RU2324049C2 - Installation and utilisation of replaceable heaters in carbohydrate pool - Google Patents

Abstract

FIELD: oil and gas industry; methods and systems for producing carbohydrates (CH).

SUBSTANCE: system, capable to heat at least part of CH pool, contains heater, which can be placed in bed borehole and retrieved to transfer heat from heater to bed with purpose of thermal decomposition. Heater presents type of electric conductor inside tube, which can be installed and/or removed from open or uncased segment with use of coil or installation/removal system with reeled pipes. At the same time, heater can be used at least in one more alternative open or uncased borehole segment in bed.

EFFECT: productivity efficiency and reliability are increased; cost of heating method and system is reduced.

20 cl, 18 dwg

Description

FIELD OF THE INVENTION

This invention relates generally to methods and systems for producing hydrocarbons and / or other products from various hydrocarbon containing formations. Some embodiments relate to the installation of relocatable heaters in hydrocarbon containing formations and / or for using relocatable heaters to supply heat to hydrocarbon containing formations.

State of the art

Hydrocarbons mined from underground (e.g., sedimentary) formations are often used as sources of energy, raw materials and consumer products. Concerns over the depletion of available hydrocarbon resources and a decrease in the overall quality of produced hydrocarbons have led to the development of processes for more efficient extraction, processing and / or use of available hydrocarbon resources. In-situ processes can be used to extract hydrocarbon materials from underground formations. The chemical and / or physical properties of hydrocarbon materials within a subterranean formation sometimes need to be changed to allow easier recovery from subterranean formations. Chemical and physical changes may include in-situ reactions, which can result in the removal of fluids, changes in composition, changes in solubility, changes in density, changes in phase and / or change in viscosity of the hydrocarbon material within the formation. The fluid may be, but is not limited to, a gas, liquid, emulsion, suspension and / or solid particle stream that has flow characteristics similar to a liquid stream.

You can use a heat source to heat the subterranean formation. Electric heaters may be used to heat the subterranean formation through radiation and / or conductivity. An electric heater can heat the element resistively. US Pat. No. 2,548,360 to Germain describes an electric heating element located inside a viscous oil inside a well. The heating element heats and reduces the viscosity of the oil to allow oil to be pumped out of the well. US Pat. No. 4,716,960 to Eastlund et al. Describes the electrical heating of an oil well tubing by passing a relatively low voltage current to prevent the formation of solids. US Pat. No. 5,065,818 to Van Egmond describes an electric heating element that is cemented into a test well without a sheath surrounding the heating element.

US Pat. No. 6,023,554 to Vinegar et al. Describes an electric heating element that is located in a shell. The heating element creates radiation energy that heats the shell. A granular solid filler material may be located between the shell and the formation. The shell due to conductivity can heat the filling material, which in turn, due to the conductivity heats the formation.

US Pat. No. 4,570,715 to Van Meurs et al. Describes an electric heating element. The heating element has an electrically conductive core surrounded by a layer of insulating material and a metal casing surrounding it. The conductive core may have a relatively low resistance at high temperatures. The insulation material may have electrical resistance, compressive strength, and heat-conducting properties that are relatively high at high temperatures. Insulation material can prevent the formation of an electric arc between the core and the metal casing. The metal casing may have tensile strength and flow resistance, which are relatively high at high temperatures.

US Pat. No. 5,060,287 to Van Egmond describes an electric heating element having a copper-nickel alloy core.

Combustion can be used to heat the formation. Burning fuel to heat the formation can be more economical than using electrical energy to heat the formation. Several different types of heaters can use fuel combustion as a source of heat that heats the formation. Combustion may occur within the formation, in the well and / or near the surface. Combustion in the formation may be in situ combustion. An oxidizer can be ignited to advance the front of the fire towards the production well. The oxidizing agent injected into the formation may flow through the formation along fault lines in the formation. The ignition of the oxidizing agent may not lead to the formation of a fire front passing evenly through the formation.

Flameless combustion chambers can be used to burn fuel inside the formation. U.S. Patent Nos. 5,255,742 issued to Mikus, 5404952 issued to Vinegar et al., 5862858 to Wellington et al. Describe flameless combustion chambers. Flameless combustion can be carried out by pre-heating the fuel and air to a temperature above the temperature of the spontaneous combustion of the mixture. Fuel and air can be mixed in the heating zone for combustion. In the heating zone of the flameless combustion chamber, a catalytic surface may be provided to lower the temperature of spontaneous combustion of the mixture of fuel and air.

Heat can be supplied to the formation from a surface heater. A surface heater can produce combustible gases that circulate through wells to heat the formation. Alternatively, surface burners can be used to heat the heat transfer fluid that passes through the well to heat the formation. Examples of fired heaters or surface burners that can be used to heat an underground formation are shown in US Pat. No. 6,056,057 to Vinegar et al. And US Pat. No. 6,079,499 to Mikus et al.

From the above it follows that considerable efforts have been made to develop methods and systems for the economical production of hydrocarbons, hydrogen and / or other products from hydrocarbon containing formations. However, currently there are still hydrocarbon containing formations from which it is not economically feasible to produce hydrocarbons, hydrogen and / or other products. Thus, there is still a need for improved methods and systems for the extraction of hydrocarbons, hydrogen and / or other products from various hydrocarbon containing formations. In some applications, it may be useful to place the heaters in the holes in the formation, so that the heaters can be removed from the hole. In some cases, heaters can be relocated to another hole in the formation. Heaters can also be removed to inspect and / or repair heaters. The ability to remove, replace and / or relocate the heater favorably affects the cost of equipment and / or operation of the in-situ process.

Disclosure of invention

One or more heaters may be located inside the hole in the hydrocarbon containing formation, so that the heaters transfer heat to the formation. In some embodiments, the heater may be located in an open well in the formation. An “open hole” in a formation may be without a shell or an “uncased well”. Heat can be transferred from the heater to the formation due to conductivity or radiation. Alternatively, the heater may be located inside a heating well, which may be clogged with gravel, sand and / or cement, or in a heating well with a sheath.

In one embodiment, the heater may comprise a conductor-in-channel heater. The conductor may be located inside the channel. The conductor may provide heat for at least a portion of the formation. A centralizer can be connected to the conductor. The centralizer may impede the movement of the conductor within the channel. The conductor-type heater in the channel may be configured to be removed from the hole in the formation.

The supply of electric current to the conductor can provide heat for part of the formation. The generated heat can be transferred from the conductor to part of the formation. Heat can lead to the pyrolysis of certain hydrocarbons in a part of the formation.

In one embodiment, it is possible to assemble a conductor-type heater in a channel having a desired length. The conductor may be placed in the channel to form a conductor-type heater in the channel. Two or more conductor-type heaters in a channel may be connected to each other to form a heater having a desired length. The conductors of the conductor type heaters in the channel may be electrically connected to each other. Additionally, the channels can be electrically connected to each other. The desired length of the conductor in the channel may be located in the hole in the hydrocarbon containing formation. In some embodiments, individual sections of a conductor-in-channel heater can be connected using active gas welding to protect the weld zone.

In some embodiments, a heater of a desired length can be collected in the vicinity of a hydrocarbon containing formation. Then the assembled heater can be coiled. The heater may be placed in a hydrocarbon containing formation by unwinding the heater into an opening in the hydrocarbon containing formation.

In one embodiment, heat may be provided by one or more heaters for a portion of the formation. The heat provided may be transferred to a selected section of the formation. A mixture can be mined from the formation. The mixture may contain at least some pyrolyzed hydrocarbons. In some embodiments, the heater can be removed from the hole in the formation and re-placed in at least one alternative hole in the formation.

Brief Description of the Drawings

Advantages of the present invention will follow for those skilled in the art from the following detailed description of embodiments with reference to the drawings, in which:

figure 1 - stage heating containing hydrocarbons;

2 is a diagram of an embodiment of a portion of an in-situ conversion system for processing a hydrocarbon containing formation;

figure 3 is an embodiment of a heat source in the form of a natural distributed furnace;

4 is an embodiment of a heat source in the form of an insulated conductor;

5 is an embodiment of heaters with three insulated conductors located inside the channel;

6 is an embodiment of a conductor type heat source in a channel in a formation;

Fig.7 is a sectional view of an embodiment of a replaceable heat source of the type conductor in the channel;

Fig. 8 is an embodiment of a wellhead with a conductor type heat source in a channel;

Fig.9 is a diagram of an embodiment of a conductor-type heater in a channel in which a portion of the heater is located substantially horizontally within the formation;

figure 10 - embodiment of the connection of the heater type conductor in the channel on an enlarged scale;

11 is a diagram of an embodiment of a conductor-type heater in a channel in which a portion of the heater is located substantially horizontally in the formation;

12 is a diagram of an embodiment of a conductor-type heater in a channel in which a portion of the heater is located substantially horizontally in the formation;

13 is a diagram of an embodiment of a conductor-type heater in a channel in which a portion of the heater is located substantially horizontally in the formation;

Fig - embodiment of the centralizer;

Fig - embodiment of the centralizer;

Fig - embodiment of the Assembly of the heat source type conductor in the channel and install the heat source in the reservoir;

17 is an embodiment of a conductor type heat source in a channel for installation in a formation;

Fig. 18 is an embodiment of a heat source in a formation.

Although various modifications and alternative embodiments are possible, the drawings show specific embodiments as examples, which are described below. Drawings may not scale. However, it should be noted that the drawings and their detailed description should not limit the invention to the disclosed particular embodiments, but rather, the invention covers all modifications, equivalents and alternatives that are included in the idea and scope of the invention defined by the attached claims.

The implementation of the invention

The following description generally relates to systems and methods for treating a hydrocarbon containing formation (e.g., a coal containing formation (including lignite, sapropelite, etc.), oil shale, carbon shale, shungite, kerogen, bitumen, oil, kerogen and oil in a matrix with low permeability, heavy hydrocarbons, asphaltites, natural mineral waxes, formations in which kerogen blocks the production of other hydrocarbons, etc.). Such formations can be processed to produce relatively high quality hydrocarbon products, hydrogen and other products.

“Hydrocarbons” generally mean molecules formed primarily by carbon and hydrogen atoms. Hydrocarbons may also contain other elements, such as, but not limited to, halogens, metal elements, nitrogen, oxygen and / or sulfur. Hydrocarbons can be, but are not limited to, kerogen, bitumen, pyrobitumen, oil, natural mineral waxes and asphalts. Hydrocarbons can be located inside or adjacent to mineral matrices inside the earth. Matrices may include, but are not limited to, sedimentary rock, sands, silicites, carbonates, diatomites and other porous media. “Hydrocarbon liquids” are liquids that contain hydrocarbons. Hydrocarbon fluids may include, entrain, or be entrained in non-hydrocarbon fluids (e.g., hydrogen (H ₂ ), nitrogen (N ₂ ), carbon monoxide, carbon dioxide, hydrogen sulfide, water, and ammonia).

A “formation” includes one or more hydrocarbon-containing layers, one or more non-hydrocarbon layers, a cover layer and / or an underburden. The “overburden” and / or “underburden” includes one or more types of impermeable materials. For example, the overburden and / or underburden may include rock, shale, mudstone, or wet / dense carbonate (i.e., impermeable carbonate without hydrocarbons). In some embodiments of the in-situ conversion process, the overburden and / or underlying layer may include a hydrocarbon-containing layer or hydrocarbon-containing layers that are relatively impermeable and not exposed to temperature during the conversion process, resulting in a significant change in the performance of the hydrocarbon-containing overburden layers and / or the underlying layer. For example, the underlying layer may contain shale or mudstone. In some cases, the overburden and the underburden may be somewhat permeable.

The terms “formation fluids” or “produced fluids” refer to fluids removed from a hydrocarbon containing formation and may include pyrolysis fluid, synthesis gas, mobile hydrocarbon, and water (steam). The term “moving fluid” refers to fluids within a formation that are capable of flowing as a result of heat treatment of the formation. Formation fluids may include hydrocarbon fluids as well as non-hydrocarbon fluids.

A “heat source" is any system for providing heating of at least a portion of a formation substantially by heat transfer via conductivity and / or radiation. For example, the heat source may include electric heaters, such as an insulated conductor, an elongated element and / or a conductor located inside the channel. The heat source may also include heat sources that generate heat by burning fuel outside or inside the formation, such as surface burners, downhole gas burners, flameless distributed furnaces, and natural distributed furnaces. Additionally, it is contemplated that in some embodiments, heat generated or generated in one or more heat sources can be supplied by other energy sources. Other heat sources may directly heat the formation, or energy may be supplied to a heat transfer medium that directly or indirectly heats the formation. It should be noted that one or more heat sources that supply heat to the formation can use various energy sources. For example, with a given formation, some heat sources can supply heat from electric resistive heaters, some heat sources can supply heat through combustion, and some heat sources can generate heat from one or more other energy sources (for example, chemical reactions, solar energy, wind energy, biomass or other sources of renewable energy). A chemical reaction may include an exothermic reaction (e.g., an oxidation reaction). The heat source may include a heater that provides heat to an area close to and / or surrounding a heating location, such as a heating well.

A “heater” is any system for generating heat in a well or in an area near a well. Heaters may include, but are not limited to, electric heaters, burners, combustion chambers that react with material within the formation or produced from the formation (e.g., natural distributed furnaces), and / or combinations thereof. “Heat source block” refers to several heat sources that form a group that repeats to create a pattern of heat sources within the formation.

The term “well” refers to a hole in a formation made by drilling or introducing a channel into the formation. The well may have a substantially circular cross-section or other cross-sectional shapes (e.g., circular, oval, rectangular, triangular, slotted, or other regular or irregular shapes). In this description, the concepts of "well" and "hole", when they refer to a hole in the reservoir, can be used with the replacement of the concept of "well".

"Naturally distributed furnace" refers to a heater that uses an oxidizing agent to oxidize at least a portion of the carbon in the formation in order to generate heat, and oxidation occurs near the well. Most of the combustion products created in a natural distributed furnace are removed through the borehole.

“Holes” refer to openings (eg, openings in channels) having a wide variety of sizes and cross-sectional shapes, including, but not limited to, circular, oval, square, rectangular, triangular, slotted, or other regular or non-regular shapes.

“Reaction zone” refers to the volume of a hydrocarbon containing formation that undergoes a chemical reaction, such as an oxidation reaction.

"Insulated conductor" refers to any elongated material that is capable of conducting electricity and which is coated, partially or completely, with electrically insulating material. The term “self-management” refers to controlling the output of a heater without external control of any type.

“Pyrolysis fluids” or “pyrolysis products” refer to fluids produced substantially during the pyrolysis of hydrocarbons. Fluids produced by pyrolysis reactions can mix with other fluids in the formation. A mixture is considered a pyrolysis fluid or a pyrolysis product. As used herein, a “pyrolysis zone” refers to a volume of a formation (eg, relative to a permeable formation, such as a tar sands formation) that is reacted or reacted to form a pyrolysis fluid.

"Condensable hydrocarbons" are hydrocarbons that condense at 25 ° C and absolute pressure in one atmosphere. Condensable hydrocarbons may include a mixture of hydrocarbons having a carbon number of more than 4. “Non-condensable hydrocarbons” are hydrocarbons that do not condense at 25 ° C. and an absolute pressure of less than one atmosphere. Non-condensable hydrocarbons may include a mixture of hydrocarbons having a carbon number of less than 5.

Hydrocarbons in formations can be treated in various ways to produce many different products. In some embodiments, such formations can be treated in several stages. Figure 1 shows several stages of heating a hydrocarbon containing formation. Figure 1 shows an example of production (in barrels of oil equivalent per tonne) (along the y axis) of the formation fluid from the hydrocarbon containing formation, depending on the temperature (in ° C) (along the x axis) of the formation (when the formation is heated at a relatively low speed) .

Methane desorption and evaporation of water occurs during stage 1 of the heating. The heating of the formation in stage 1 can be carried out as quickly as possible. For example, upon initial heating of a hydrocarbon containing formation, hydrocarbons in the formation may desorb adsorbed methane. Desorbed methane can be extracted from the reservoir. If the hydrocarbon containing formation is further heated, then the water contained within the hydrocarbon containing formation may evaporate. Water may occupy in some hydrocarbon containing formations between about 10% and about 50% of the pore volume in the formation. In other formations, water may occupy larger or smaller parts of the pore volume. Water usually evaporates in the formation at temperatures between about 160 ° C and about 285 ° C and at pressures from about 6 bar (absolute value) to about 70 bar (absolute value). In some embodiments, evaporated water may cause a change in wettability in the formation and / or an increase in pressure of the formation. Changes in wettability or elevated pressure can affect pyrolysis reactions or other reactions in the formation. In some embodiments, evaporated water may be produced from the formation. In other embodiments, evaporated water may be used to isolate and / or distill steam in or out of the well. Removing water and increasing pore volume in the formation can increase the storage space for hydrocarbons within the pore volume.

After the heating step 1, the formation can be heated further, so that the temperature inside the formation reaches (at least) the initial pyrolysis temperature (for example, the temperature at the lower end of the temperature range shown in FIG. 2). During stage 2, pyrolysis of hydrocarbons within the formation may occur. The pyrolysis temperature range may vary depending on the type of hydrocarbon within the formation. The pyrolysis temperature range may include temperatures between about 250 ° C and about 900 ° C. The pyrolysis temperature range for the extraction of the desired products can extend only in part of the full pyrolysis temperature range. In some embodiments, the pyrolysis temperature range for producing the desired products may include temperatures between about 250 ° C and about 400 ° C. If the temperature of hydrocarbons in the formation is slowly raised in the temperature range from about 250 ° C to about 400 ° C, then the creation of pyrolysis products can be essentially completed when the temperature approaches 400 ° C. Heating a hydrocarbon containing formation with several heat sources can create temperature gradients around heat sources that slowly increase the temperature of the hydrocarbons in the formation in the pyrolysis temperature range.

In some in-situ conversion embodiments, the temperature of the hydrocarbons to be pyrolyzed can not be increased slowly in the pyrolysis temperature range from about 250 ° C. to about 400 ° C. Hydrocarbons in the formation can be heated to the desired temperature (for example, about 325 ° C). Other temperatures may be selected as desired temperatures. Applying heat from heat sources can achieve the desired temperature relatively quickly and efficiently in the formation. The introduction of heat into the formation from heat sources can be adjusted to maintain the temperature in the formation at substantially the desired temperature. Hydrocarbons can be maintained substantially at the desired temperature until the pyrolysis decreases, so that the production of the desired fluids from the formation becomes not economical.

Formation fluids, including pyrolysis fluids, may be produced from the formation. Pyrolysis fluids may include, but are not limited to, hydrocarbons, hydrogen, carbon dioxide, carbon monoxide, hydrogen sulfide, ammonia, nitrogen, water, and mixtures thereof. As the temperature of the formation increases, the amount of condensable hydrocarbons in the produced fluids of the formation tends to decrease. At high temperatures, mainly methane and / or hydrogen can be extracted from the formation. If the hydrocarbon containing formation is heated over the entire pyrolysis range, then only small amounts of hydrogen can be produced from the formation near the upper limit of the pyrolysis range. After depletion of all available hydrogen, a minimum amount of fluid is typically produced from the formation.

After pyrolysis of hydrocarbons, a large amount of carbon and some hydrogen are still present in the formation. A significant portion of the remaining carbon in the formation can be produced from the formation in the form of synthesis gas. Generation of synthesis gas may occur during stage 3, shown in figure 1. Stage 3 may include heating the hydrocarbon containing formation to a temperature sufficient to permit generation of synthesis gas. For example, synthesis gas can be produced within a temperature range from about 400 ° C to about 1200 ° C. The temperature of the formation, when the synthesis gas generating fluid is introduced into the formation, can determine the composition of the synthesis gas produced from the formation. If the synthesis gas generating fluid is injected into the formation at a temperature sufficient to ensure the generation of synthesis gas, synthesis gas may be generated within the formation. Generated synthesis gas can be removed from the formation through a production well or production wells. During the generation of the synthesis gas, a large volume of the generated synthesis gas can be produced.

Figure 2 shows a diagram of an embodiment of a portion of an in-situ conversion system for treating a hydrocarbon containing formation. Heat sources 100 may be located within at least a portion of the hydrocarbon containing formation. Heat sources 100 may include, for example, electric heaters such as insulated conductors, conductor-in-channel heaters, surface burners, flameless distributed furnaces and / or natural distributed furnaces. Heat sources 100 may also include other types of heaters. Heat sources 100 may provide heating for at least a portion of the hydrocarbon containing formation. Energy can be supplied to the heat sources 100 through the supply lines 102. The supply lines may have a different structure depending on the type of heat source or heat sources used to heat the formation. Supply lines for heat sources can transmit electrical energy to electric heaters, can transport fuel for furnaces, or they can transport heat-transfer fluid that circulates inside the formation.

Production wells 104 may be used to remove fluid from the formation. Formation fluid produced from production wells 104 can be transported through a manifold piping 106 to processing units 108. Formation fluids can also be extracted from sources of 100 heat. For example, it is possible to produce fluid from heat sources 100 to control pressure within the formation near heat sources. Fluid produced from heat sources 100 can be transported through pipes or pipelines to a manifold piping 106, or produced fluid can be transported through pipes or pipelines directly to treatment plants 108. Processing units 108 may include separation units, reaction units, quality improvement units, fuel cells, turbines, storage tanks, and other systems and units for processing produced formation fluids.

The in-situ conversion system for treating hydrocarbons may include barrier wells 110. In some embodiments, barriers can be used to prevent the migration of fluids (eg, generated fluids and / or groundwater) to and / or from the portion of the formation in which the in-situ conversion process is performed. Barriers may include, but are not limited to, naturally present parts (e.g., overburden and / or underburden), freeze wells, frozen barrier zones, low temperature barrier zones, cemented walls, sulfur wells, dewatering wells, injection wells, a barrier formed gel created in the formation, a barrier formed by the deposition of salts in the formation, a barrier formed by a polymerization reaction in the formation, sheets introduced into the formation, or a combination thereof.

As shown in FIG. 2, in addition to the heat sources 100, typically one or more production wells 104 may be located within a portion of the hydrocarbon containing formation. Formation fluids can be produced from production wells 104. In some embodiments, production well 104 may comprise a heat source. A heat source can heat parts of a formation at or near a production well and provides for removal of the vapor phase of the formation fluids. The need to pump high temperature fluids from a production well can be reduced or eliminated. Eliminating or restricting the pumping of high temperature fluids can significantly reduce the cost of production. Providing heating to or through the production well may: (1) inhibit condensation and / or reflux of the produced fluid when such produced fluid moves in the production well near the overburden, (2) increase heat input to the formation and / or (3) increase the permeability of the formation at or near a production well. In some embodiments of the in-situ conversion process, the amount of heat supplied to production wells is significantly less than the amount of heat supplied to heat sources that heat the formation.

In one embodiment, the hydrocarbon containing formation can be heated using a system of naturally distributed furnaces located in the formation. The generated heat may be allowed to be transferred to a selected section of the formation.

A temperature sufficient to maintain oxidation may be at least about 200 ° C or 250 ° C. A temperature sufficient for oxidation may vary depending on many factors (for example, the composition of the hydrocarbons in the hydrocarbon containing formation, the water content in the formation and / or the type and amount of oxidizing agent). Some water can be removed from the formation before heating. For example, water can be pumped out of the formation using dewatering wells. The heated portion of the formation may be near or substantially adjacent to the opening in the hydrocarbon containing formation. The hole in the formation may be a heating well formed in the formation. The heated portion of the hydrocarbon containing formation may extend radially from the hole to a width of about 0.3 m to about 1.2 m. However, the width may also be less than 0.9 m. The width of the heated portion may vary over time. In some embodiments, the change depends on factors including the width of the formation necessary to generate enough heat during carbon oxidation to support the oxidation reaction without supplying heat from an additional heat source.

After the part of the formation reaches a temperature sufficient to maintain oxidation, it is possible to feed the oxidizing fluid into the hole to oxidize part of the hydrocarbons in the reaction zone or in the zone of the heat source inside the formation. Hydrocarbon oxidation generates heat in the reaction zone. The generated heat in most embodiments is transferred from the reaction zone to the pyrolysis zone in the formation. In some embodiments, the generated heat is transferred at a speed between about 650 W per meter and between about 1650 W per meter when measured along the depth of the reaction zone. After the oxidation of at least some hydrocarbons in the formation, the energy supplied to the heater to initially heat the formation to a temperature sufficient to maintain oxidation can be reduced or disabled. The cost of energy input can be significantly reduced by using natural distributed furnaces, which provides a much more efficient system for heating the formation.

In one embodiment, a channel may be provided in the hole for supplying oxidizing fluid to the hole. The channel may have flow openings or other flow control mechanisms (eg, slots, venturi meters, valves, etc.) to allow fluid to flow into the opening. The term “openings” includes openings having various cross-sectional shapes, including, but not limited to, circular, oval, square, rectangular, triangular, slotted, or other regular or non-regular shapes. The flow openings may in some embodiments be critical flow openings. The flow openings can provide a substantially constant flow of oxidizing fluid into the opening, regardless of the pressure in the opening.

The flow of oxidizing fluid into the hole can be controlled so that the oxidation rate in the reaction zone is controlled. The heat transfer between the inlet oxidizing agent and the outgoing oxidation products can heat the oxidizing fluid. Heat transfer can also keep the channel below the operating temperature of the channel.

Figure 3 shows an embodiment of a natural distributed furnace that can heat a hydrocarbon containing formation. Channel 112 may be located at hole 114 in hydrocarbon reservoir 116. Channel 112 may be internal channel 118. Oxidation fluid source 120 may supply oxidative fluid 122 to internal channel 118. Internal channel 118 may have critical flow openings 124 along its length. Critical flow holes 124 may be spirally (or any other pattern) along the length of the inner channel 118 in the hole 114. For example, critical flow holes 118 may be spirally located with a distance of from about 1 m to about 2.5 m between adjacent holes. The inner channel 118 may be sealed at the bottom. Oxidizing fluid 122 may be supplied to hole 114 through holes 124 of the critical flow of internal channel 118.

Critical flow openings 124 can be configured to provide substantially the same flow rate of oxidizing fluid 122 through each critical flow opening. Critical flow openings 124 can also provide a substantially uniform flow of oxidizing fluid 122 along the length of the internal channel 118. Such a flow can provide substantially uniform heating of the hydrocarbon layer 116 along the length of the internal channel 118.

Packaging material 126 may surround the channel 112 in the overburden 128 of the formation. Packaging material 126 may inhibit fluid flow from opening 114 to surface 130. Packaging material 126 may include any material that inhibits fluid flow to surface 130, such as cement, compacted sand or gravel. A channel or opening through the packaging material may provide a path for products to oxidize to surface.

The oxidation products 132 typically enter the channel 112 from the opening 114. The oxidation products 132 may include carbon dioxide, nitrogen oxides, sulfur oxides, carbon monoxide and / or other products resulting from the reaction of oxygen with hydrocarbons and / or carbon. The oxidation products 132 can be removed through the channel 112 to the surface 130. The oxidation products 132 can flow along the surface of the reaction zone 134 into the hole 114 almost to the upper end of the hole 114, where the oxidation products 132 can flow into the channel 112. The oxidation products 132 can also be removed through one or more channels located in the hole 114 and / or in the hydrocarbon layer 116. For example, oxidation products 132 can be removed through a second channel located in the hole 114. Removing oxidation products 132 through the channel may prevent product from flowing 132 s oxidation of a production well located in a formation. Critical flow openings 124 may also prevent oxidation products 132 from entering the internal channel 118.

The flow rate of the oxidation products 132 can be balanced with the flow rate of the oxidizing fluid 122, so that a substantially constant pressure is maintained within the bore 114. For a heating section 100 m long, the oxidizing fluid flow rate can be between 0.5 standard cubic meters to about 5 standard cubic meters per minute, or from about 1.0 standard cubic meter to about 4 standard cubic meters per minute, or for example, about 1.7 standard cubic meters per minute. The flow rate of oxidizing fluid into the formation can be gradually increased during use to match the expansion of the reaction zone. The pressure in the hole may be, for example, about 8 bar (absolute value). Oxidizing fluid 122 may oxidize at least a portion of the hydrocarbons in the heated portion 136 of the hydrocarbon layer 116 in the reaction zone. The heated portion 136 can be preheated to a temperature sufficient to maintain oxidation using an electric heater. In some embodiments, an electric heater may be placed inside or attached to the outside of the inner channel 118.

In some embodiments, pressure control within the bore 114 may inhibit the passage of oxidation products and / or oxidative fluids into the formation pyrolysis zone. In some cases, the pressure inside the hole 114 can be controlled so that it is slightly greater than the pressure in the formation, in order to ensure that the fluid flows inside the hole into the formation, but to prevent the formation of a pressure gradient that allows the fluid to be transported sufficiently far into the formation.

Although heat from oxidation is transferred to the formation, oxidation products 132 (and excess oxidizing fluid such as air) are excluded from passing through the formation and / or to a production well in the formation. Instead, oxidation products 132 and / or excess oxidative fluid can be removed from the formation. In some embodiments, the oxidation product and / or excess oxidative fluid is removed through channel 112. Removing the oxidation products and / or excess oxidative fluid can provide heat transfer from the oxidation reactions to the pyrolysis zone without entering a significant amount of the oxidation product and / or excess oxidative fluid into the zone pyrolysis.

The heat generated in the reaction zone 134 can be transferred through heat conduction to the selected section 138 of the hydrocarbon layer 116. In addition, the generated heat can be transferred from the reaction zone to the selected section to a lesser extent by convective heat transfer. The selected section 138, sometimes referred to as the "pyrolysis zone", may be substantially adjacent to the reaction zone 134. Removing the oxidation product (and excess oxidizing fluid, such as air) can provide heat to the pyrolysis zone from the reaction zone without affecting the oxidation product or oxidizing agents present in the reaction zone. The oxidation product and / or oxidizing fluids can lead to the formation of undesirable products if they are present in the pyrolysis zone. Removal of the oxidation product and / or oxidizing fluids may provide support for the reduction conditions in the pyrolysis zone.

In some embodiments, a second channel may be located in the hole 114 of the heater in the form of a naturally distributed firebox. The second channel can be used to remove oxidation products from the hole 114. The second channel may have holes located along its length. In some embodiments, oxidation products can be removed from the upper zone of the hole 114 through holes located on the second channel. The holes can be arranged along the length of the second channel so that more oxidation products can be removed from the upper zone of the hole 114.

In some embodiments of the natural distributed furnace, openings on the second channel may be opposite the critical flow openings 124 on the internal channel 118. Such an orientation may prevent the oxidizing fluid from flowing through the internal channel 118 from passing directly to the second channel.

An electric heater may heat a portion of the hydrocarbon containing formation to a temperature sufficient to support hydrocarbon oxidation. The portion may be located close to or substantially adjacent to the hole in the formation. The part may extend radially with a width of less than about 1 m from the opening. The electric current supplied to the electric heater can be gradually reduced or turned off. A natural distributed firebox can be used in conjunction with an electric heater to provide a method with a reduced energy input cost for heating a hydrocarbon containing formation compared to using only an electric heater.

An insulated conductor heater may be a heating element of a heat source. In one embodiment of the insulated conductor heater, the insulated conductor heater is a mineral insulated cable or rod. An insulated conductor heater may be placed in a hole in a hydrocarbon containing formation. An insulated conductor heater may be placed in an open hole in a hydrocarbon containing formation. Placing a heater with an insulated conductor in an open hole in a hydrocarbon containing formation may transfer heat from the heater to the formation using radiation as well as conductivity. Using an open hole may facilitate removal, if necessary, of the heater from the well. Using an open hole can significantly reduce the cost of heating by eliminating the need for a casing part that can withstand high temperature conditions. In some embodiments of the heater, an insulated conductor heater may be placed inside the casing in the formation; it can be cemented inside the formation or it can be packaged in a hole with sand, gravel or other filler material. An insulated conductor heater may be supported by a support member located within the opening. The support member may be a cable, rod, or conduit (e.g., pipe). The support element may be made of metal, ceramic, inorganic material, or combinations thereof. Parts of the support member can be exposed to formation fluids and heat during use, so that the support member can be chemically stable and heat resistant.

Clamps, spot welding, and other types of joints can be used to connect a heater with an insulated conductor to a support element in various places along the length of the heater with an insulated conductor. The support element may be attached to the wellhead on the upper surface of the formation. In one embodiment of the insulated conductor heater, the insulated conductor heater is provided with sufficient structural strength, so that there is no need for a support member. In many cases, an insulated conductor heater has some flexibility to prevent damage due to thermal expansion during heating or cooling.

In some embodiments, insulated conductor heaters may be located in wells without support elements and / or centralizers. An insulated conductor heater without support elements and / or centralizers may have a suitable combination of temperature and corrosion resistance, creep strength, length, thickness (diameter) and metal composition to prevent failure of the insulated conductor during use.

Many firms make insulated conductor heaters. Such manufacturers include, but are not limited to, MI Cable Technologies (Calgary, Alberta), Pyrotenax Cable Company (Trenton, Ontario), Idaho Laboratories Corporation (Idaho Falls, Idaho) and Watlow (St. Louis, Montana). For example, an insulated conductor heater can be ordered from Idaho Laboratories as a model cable 355-A90-310- "H" 30 '/ 750' / 30 'with an Inconel 600 sheath for a Y-shaped three-phase configuration with cold pins and conductors connected to the bottom . The heater specification may also include a 1000 VAC cable and for temperatures up to 1400 ° F. Designation 355 defines the outer diameter of the cable (0.355 inches); A90 indicates conductor material; 310 indicates a shell alloy in a heating zone (SS310); “H” means a mixture of MgO; and 30 '/ 750' / 30 'indicates a heating zone with a length of 230 m with a top with cold pins and a bottom having a length of about 9 m. A similar part number with the same specification using standard purity MgO cable can be ordered from Pyrotenax Cable Company.

One or more insulated conductor heaters may be placed inside a hole in the formation to form a heater or heaters. Electric current can be passed through each heater with an insulated conductor in the hole for heating the formation. Alternatively, electric current can be passed through selected heaters with an insulated conductor in the hole. Unused conductors may be spare heaters. Insulated conductor heaters may be electrically connected to an energy source in any conventional manner. Each end of the insulated conductor heater may be connected to a lead cable that passes through the wellhead. This configuration typically has a 180 ° bend (hairpin bend) or a bend located at the bottom of the heater. An insulated conductor heater that includes bending or turning through 180 ° does not require a lower end, however bending or turning through 180 ° may mean electrical and / or structural attenuation of the heater. Insulated conductor heaters can be electrically connected to each other in series, in parallel, or in combination in series and parallel. In some embodiments of the heaters, electric current can be passed through the heater conductor with an insulated conductor and returned through the shell of the heater with an insulated conductor.

In the embodiment of the heater shown in FIG. 4, three heaters 140 are electrically connected to a three-phase Y-shape configuration with a power source. The power source can supply alternating current with a frequency of 60 Hz to electrical conductors. Insulated conductor heaters may not require bottom connections. As an alternative solution, all three conductors of a three-phase circuit can be connected to each other near the bottom of the heater opening. The connection can be made directly at the ends of the heating sections of the insulated conductor heaters or at the ends of the cold pins connected to the heating sections at the bottom of the insulated conductor heaters. The lower connections can be made using insulator filled and sealed enclosures or epoxy resin filled enclosures. The insulator may have the same composition as the insulator used for electrical insulation.

The three insulated conductor heaters shown in FIG. 4 can be connected to the support member 142 using centralizers 144. As an alternative, the three insulated conductor heaters can be attached directly to the support pipe using metal clamps. Centralizers 144 may hold or inhibit the movement of insulated conductor heaters 140 on support elements 142. Centralizers 144 may be made of metal, ceramic, or combinations thereof. The metal may be stainless steel or any other type of metal capable of withstanding corrosive and hot conditions. In some embodiments, centralizers 144 may be curved metal strips welded to the support member at a distance of less than about 6 m from each other. The ceramics used in centralizers 144 may be, but are not limited to, Al ₂ O ₃ , MgO, or another insulator. Centralizers 144 can hold the position of insulated conductor heaters 140 on the support members 142, so that insulated conductor heaters are not allowed to move at insulated conductor heaters. Insulated conductor heaters 140 may also be somewhat flexible to withstand the expansion of the support member 142 during heating.

The support member 142, the insulated conductor heater 140, and centralizers 144 may be located in the hole 114 in the hydrocarbon layer 116. The insulated conductor heaters 140 may be connected to the bottom conductor connection 146 using a transition pin 148 with cold pins. The bottom conductor connection 146 may electrically connect the insulated conductor heaters 140 to each other. The bottom conductor connection 146 may include materials that are electrically conductive and do not melt at temperatures present in the hole 114. The cold pin adapter conductor 148 may be an insulated conductor heater having a lower electrical resistance than an insulated conductor heater 140.

The lead conductor 150 may be connected to the wellhead 152 to supply electrical energy to the insulated conductor heater 140. The lead conductor 150 may be made of a conductor with a relatively small electrical resistance, so that relatively little heat is generated when electric current passes through the lead conductor 150. In some embodiments, lead conductor 150 is a multi-core copper cable with rubber or polymer insulation. In some embodiments, lead conductor 150 may be a mineral insulated conductor and a copper core. The lead conductor 150 may be connected to the wellhead 152 on the surface 130 through a sealing flange located between the overburden 128 and the surface 130. The sealing flange may prevent fluid from leaving the hole 114 on the surface 130.

In some embodiments, reinforcing material 154 may protect the casing 156 in the overburden from the overburden 128. In one embodiment, the casing in the overburden is a 7.6 cm (3 in) pipe of process 40. The reinforcing material 154 may include e.g. Portland cement grades G and H mixed with silica powder to improve high temperature performance, slag or silica powder and / or a mixture thereof (e.g. 1.58 g per cubic centimeter of slag / powder dio silicon xide). In some embodiments of the heater, reinforcing material 154 extends in a radial direction with a width of from about 5 cm to about 25 cm. In some embodiments, reinforcing material 154 can extend in a radial direction with a width of from about 10 cm to about 15 cm.

In some embodiments, one or more channels may be provided to supply additional elements (e.g., nitrogen, carbon dioxide, reducing reagents, such as gas containing hydrogen, etc.) into the formation openings to release fluids and / or to pressure control. Formation pressures are usually maximum near heat sources. Using pressure control equipment in heaters can be helpful. In some embodiments, the addition of a reducing reagent near a heat source helps to provide more favorable pyrolysis conditions (e.g., a greater partial pressure of hydrogen). Since permeability and porosity tend to increase more rapidly near a heat source, it is often optimal to add a reducing reagent near a heat source so that the reducing reagent can more easily move into the formation.

Channel 158, shown in FIG. 4, may be provided to add gas from gas source 160 through valve 162 and to orifice 114. Channel 158 and valve 164 may be used at different times to relieve pressure and / or control pressure near orifice 114. It should be note that any of these heat sources may also be provided with channels for supplying additional components for the release of fluids and / or pressure control.

As shown in FIG. 4, the support member 142 and the lead conductor 150 may be connected to the wellhead 152 on the formation surface 130. Surface conductor 166 may span reinforcing material 150 and couple to wellhead 152. Embodiments of surface conductor 166 may have an outer diameter of about 22 cm. Embodiments of surface conductors may extend to a depth of from about 3 m to about 515 m into a hole in the formation. Alternatively, the surface conductor may extend to a depth of about 9 m into the hole. Electric current can be supplied from a power source to an insulated conductor heater 140 to generate heat. For example, a voltage of about 330 V and a current of about 266 A can be supplied to an insulated conductor heater 140 to generate about 1150 W / m in an insulated conductor heater 140. The heat generated by the three insulated conductor heaters 140 can be transferred (for example, by radiation) inside the opening 114 for heating at least a portion of the hydrocarbon layer 116.

Heat generated by an insulated conductor heater can heat at least a portion of the hydrocarbon containing formation. In some embodiments, heat can be transferred to the formation substantially by radiation of the generated heat into the formation. A certain amount of heat can be transferred through conduction or convection of heat due to the gases present in the hole. The hole may be an open hole. An open hole eliminates the costs associated with the thermal connection of the heater to the formation, the costs associated with the casing, and / or the costs associated with packing the heater inside the hole. Additionally, heat transfer due to radiation is usually more efficient than due to conductivity, so that heaters can operate at a lower temperature in an open well. Heat transfer due to conductivity during the initial operation of the heater can be increased by adding gas to the hole. Gas pressure can be maintained up to about 27 bar (absolute value). The gas may include, but is not limited to, carbon dioxide and / or helium. An insulated conductor heater in an open well may preferably expand or contract freely in accordance with thermal expansion and contraction. An insulated conductor heater may preferably be removed or relocated from an open well.

In one embodiment, an insulated conductor heater may be installed using a winding assembly. You can use more than one winding unit to simultaneously install both an insulated conductor and a support element. US Pat. No. 4,572,299 to Van Egmond et al. Describes the unwinding of an electric heater into a well. As an alternative solution, the support element can be installed using a coiled pipe unit. The pipe winding technology is described in PCT patents Nos. WO / 0043630 and WO / 0043631. Heaters can be rewound and connected to the support member when the support member is inserted into the well. The heater and support element can be wound from winding units. Spacers can be attached to the support member and heater along the length of the support member. Additional winding units can be used for additional electric heating elements.

In one embodiment of the in-situ conversion process, the heater may be installed in a substantially horizontal well. The installation of a heater in the well (vertical or horizontal) may include the location of one or more heaters (for example, three heaters with an insulated mineral conductor) inside the channel. FIG. 5 shows an embodiment of a portion of three insulated conductor heaters 140 located within channel 168. Insulated conductor heaters 140 may be spaced apart from channel 168 using spacers 170 to position the insulated conductor heater within the channel.

The channel can be wound on a reel. The coil may be located on a transportation platform, such as a tractor unit or other platform that can be transported to the well. The channel can be reeled from the coil at the well and introduced into the well to install a heater inside the well. A welded bowl may be located at the end of the coiled channel. The welded bowl may be located at the end of the channel, which is introduced first into the well. The channel provides a simple installation of the heater in the well. The channel may also provide support for the heater.

Installing coiled tubing can reduce the number of welded and / or threaded joints along the length of the casing. Welded and / or threaded joints can be subjected to a preliminary integrity test (for example, by means of a hydraulic test). Coiled tubing is offered by Quality Tubing, Inc. (Houston, Texas) and Precision Tubing (Houston, Texas) and other manufacturers. Coiled pipes are available in various sizes and materials. Wound pipe sizes can range from about 2.5 cm (1 inch) to about 15 cm (6 inches). Coiled pipes are available in a variety of metals, including carbon steel. Coiled pipes can be wound around large diameter drums. The drum can be supported by a pipe winder. Suitable pipe winding units are available from Halliburton (Duncan, Oklahoma), Fleet Cementers, Inc. (Cisco, Texas) and Coiled Tubing Solutions, Inc. (Eastland, Texas). Wound pipes can be wound from the drum, passed through a straightener and introduced into the well. The wellbore may be attached (for example, welded) to one end of the wound pipe before introducing the wound pipe into the well. After insertion, the wound pipe can be cut off from the pipe wound on the drum.

Figure 6 shows an embodiment of a conductor-type heater in a channel that can heat a hydrocarbon containing formation. Conductor 174 may be located in channel 176. Conductor 174 may be a rod or channel of electrically conductive material. At both ends of conductor 174, low resistance sections 178 may be provided to generate less heat in these sections. The low resistance section 178 can be made with a larger cross-sectional area of the conductor 174 in this section, or the sections can be made of a material having a lower resistance. In some embodiments, low resistance section 178 includes a low resistance conductor connected to conductor 174. In some embodiments, heaters 174 may be stainless steel rods 316, 304, or 310 with a diameter of about 2.8 cm. In some embodiments, conductors are conductors are 316, 304 or 310 stainless steel tubes with diameters of about 2.5 cm. Rods and tubes with larger or smaller diameters can be used to provide the desired heating of the formation. The diameter and / or wall thickness of the conductor 174 can be varied along the length of the conductor to provide different heating rates in different parts of the conductor.

Channel 176 may be made of electrically conductive material. For example, channel 176 may be a mode 40 pipe with a diameter of 7.6 cm made of stainless steel 316, 304, or 310. Channel 176 may be located in a hole 114 in hydrocarbon layer 116. The hole 114 has a diameter that allows for channel 176. Diameter holes can be from about 10 cm to about 13 cm. Larger or smaller diameters of the holes can be used to accommodate special channels or structures.

The conductor 174 can be located in the center of the channel 176 using centralizers 180. The centralizer 180 can electrically isolate the conductor 174 from the channel 176. The centralizer 180 can inhibit the movement and correctly position the conductor 174 inside the channel 176. The centralizer 180 can be made of ceramic material or a combination of ceramic and metallic materials. Centralizers 180 may inhibit deformation of conductor 174 in channel 176. Centralizers may be spaced apart from about 0.5 m to about 3 m along conductor 174.

A second low resistance section 178 of conductor 174 may connect conductor 174 to wellhead 152, as shown in FIG. 6. An electric current can be supplied to the conductor 174 from the supply cable 184 through the low resistance section 178 of the conductor 174. An electric current can pass from the conductor 174 through the slider 188 into the channel 176. The channel 176 can be electrically isolated from the casing 156 of the overburden and from the wellhead 156 of the well to return electric current to the supply cable 184. Heat can be generated in the conductor 174 and channel 176. Generated heat can be radiated inside the channel 176 and the hole 114 for heating at least a portion of the hydrocarbon oya 116. For example, the conductor 174 and the channel 176 of the heated section length 229 m (750 feet) can apply a voltage of about 330 V and a current of about 795 A to generate about 1150 watts / m of the conductor 174 and the channel 176.

In the overburden 128, the overburden casing 156 may be located. Casing layer casing 156 may in some embodiments be surrounded by materials that prohibit heating of the coating layer. Section 178 of the low resistance of the conductor 174 may be located in the casing 156 of the overburden. The low resistance section 178 of the conductor 174 may be made, for example, of carbon steel. The low resistance section 178 may have a diameter between about 2 cm and about 5 cm, or, for example, a diameter of about 4 cm. The low resistance section 178 of the conductor 174 may be centered on the casing of the overburden using centralizers 180. Centralizers 180 may be located at intervals of about 6 m to about 12 m or, for example, about 9 m along the low resistance section 178 of the conductor 174. In one embodiment of the heater, the low resistance section 178 of the conductor 174 is connected to the conductor by one or more welding spot. In other embodiments of the heater, low resistance section 178 may generate little and / or no heat in the casing 156 of the overburden. Packaging material 126 may be located between the overburden casing 156 and the hole 114. The packaging material 126 may prevent fluids from passing from the hole 114 to the surface 130.

In one embodiment of the heater, the overburden casing 156 is a mode 40 stainless steel pipe with a diameter of 7.6 cm. In some embodiments, the overburden casing 156 may be cemented into the overburden. Reinforcing material 154 may be slag or silica powder, or a mixture thereof (for example, about 1.58 g per cubic centimeter of slag / silica powder). The reinforcing material 154 can extend radially with a width of about 5 cm to about 25 cm. The reinforcing material 154 can also be made of a material that is designed to prohibit the passage of heat into the cover layer 128. In other embodiments of the heater, the cover casing 156 may not be cemented into the formation. The presence of a non-cemented casing of the overburden may facilitate removal of channel 176 if removal is necessary.

Surface conductor 166 may connect to wellhead 152. The surface conductor 166 may have a diameter of from about 10 cm to about 30 cm, or in some embodiments, a diameter of about 22 cm. Electrically insulating sealing flanges can mechanically connect the low resistance section 178 of the conductor 174 to the wellhead 152 and electrically connect the low resistance section 178 to supply cable 184. Electrically insulating sealing flanges can connect the supply cable 184 to the wellhead 152. For example, supply cable 184 may be a copper cable, wire, or other elongated element. Supply cable 184 may include any materials having a substantially low resistance. The power cable can be connected with a clamp to the bottom of the low resistance section of the conductor to make electrical contact.

In one embodiment, heat may be generated in or through channel 176. From about 10% to about 30%, or, for example, about 20% of the total heat generated by the heater, can be generated in the channel 176 or using it. Both conductor 174 and channel 176 may be made of stainless steel. The dimensions of conductor 174 and channel 176 can be selected so that the conductor can dissipate heat in the range from about 650 W / m to 1650 W / m. The temperature in channel 176 may be from about 480 ° C. to about 815 ° C., and the temperature of conductor 174 may be from about 500 ° C. to 840 ° C. Substantially uniform heating of the hydrocarbon containing formation may be provided along conductor 176 with a length of more than 300 m and even more than 600 m.

A channel 186 may be provided for adding gas from the gas source 160 through the valve 162 to the hole 114. A hole is provided in the reinforcing material 154 to allow gas to pass into the hole 114. The channel 186 and valve 164 can be used at different times to relieve pressure and / or control pressure close to opening 114. It should be noted that any of the heat sources described herein may be provided with channels for supplying additional components, discharging fluids, and / or pressure control.

7 shows a section of one embodiment of a replaceable conductor-type heater in a channel. The channel 176 can be placed in the hole 114 through the cover layer 128, so that there is a gap between the channel and the casing 156 of the cover layer. Fluids can be removed from the hole 114 through the gap between the channel 176 and the casing 156 of the overburden. Fluids can be removed from the gap through channel 186. Channel 176 and heater components contained within the channel, which are connected to wellhead 152, can be removed from hole 114 as a single unit. The heater can be removed as a single unit for repair, replacement and / or use in another part of the reservoir.

In some embodiments, a portion of the conductor type heater in the channel can be moved or removed to control part of the formation that is heated by the heater. For example, in a horizontal well, a conductor-in-channel heater may initially have a length equal to the length of the hole in the formation. As the product is extracted from the formation, the conductor-type heater in the channel can be moved so that it is located farther from the end of the hole in the formation. Heat can be supplied to various parts of the formation by adjusting the location of the heater. In some embodiments, one end of the heater may be coupled to a sealing mechanism (eg, a packaging mechanism or a closing mechanism) to seal the perforations in the liner or casing. The sealing mechanism may prohibit unwanted fluid production from parts of a heating well from which a conductor-type heater in a channel has been removed.

On Fig shows an embodiment of the wellhead. The wellhead 152 may be connected to the electrical junction box 190 via a flange 192 or any other suitable mechanical device. The electrical junction box 190 can control the power (current and voltage) supplied to the electric heater. A power source 194 may be included in the electrical junction box 190. In one embodiment of the heater, the electric heater is a conductor-in-channel heater. Flange 192 may contain stainless steel or any other material suitable for sealing. Conductor 196 may electrically connect channel 176 to power source 194. In some embodiments, the power source 194 may be located outside the wellhead 152, and in this case, the power source is connected to the wellhead with a power cable 184, as shown in FIG. 6. A low resistance section 178 may be coupled to the power source 194. Compressible seal 198 may seal conductor 196 on the inner surface of electrical junction box 190.

Flange 192 may be sealed with a metal ring 200 of circular cross section. Channel 202 may connect flange 192 to flange 214. Flange 214 may connect to the casing of the overburden. Flange 214 may be sealed with O-ring 204 (e.g., a metal O-ring or a steel O-ring). The conductor low resistance section 178 can be connected to the electrical junction box 190. The low resistance section 178 can pass through the flange 192. The low resistance section 178 can be sealed in the flange 192 using a circular section 218. The assembly 218 is configured to isolate the low resistance section 178 from the flange 192 and the flange 214 and can be sealed with a metal ring 200 of circular cross section. Compressible seal 198 may be configured to electrically isolate conductor 196 from flange 192 and junction box 190. Centralizers 180 may connect to low resistance section 178. Thermocouples 208 can be connected to thermocouple flange 220 using conductors 206 and wires 210. Thermocouples 208 can be enclosed in an electrically insulated sheath (eg, metal sheath). Thermocouples 208 can be sealed in thermocouple flange 220 using compressible seals 212. Thermocouples 208 can be used to monitor temperatures in the heated portion of the well. In some embodiments, fluids (e.g., vapors) can be removed through wellhead 152. For example, fluids from outer channel 176 can be removed through flange 222, or fluids can be removed inside of channel through flange 224.

FIG. 9 shows an embodiment of a conductor-type heater in a channel arranged substantially horizontally within hydrocarbon layer 116. Heated section 226 may be arranged substantially horizontally within hydrocarbon layer 116. Heater casing 238 may be located inside hydrocarbon layer 116. Casing 238 of the heater may be made of a corrosion resistant, relatively rigid material (e.g., 304 stainless steel). The casing 238 may be connected to the casing 156 of the overburden. The overburden casing 156 may contain materials such as carbon steel. In one embodiment, the overburden casing 156 and the heater casing 238 have a diameter of about 15 cm. At one end of the casing 238, an expansion mechanism 246 may be located to accommodate the thermal expansion of the channel during heating and / or cooling.

To install the heater casing 238 substantially horizontally within the hydrocarbon layer 116, the casing layer 156 of the overburden layer may bend from the vertical direction in the overburden layer 128 to the horizontal direction within the hydrocarbon layer 116. A curved well may be formed while drilling the well in the formation. Heater casing 238 and overburden casing 156 may be installed in the bent well. The radius of curvature of a bent well can be determined by drilling properties in the overburden and in the formation. For example, the radius of curvature may be about 200 m from point 234 to point 248.

Channel 176 may be located within heater casing 238. In some embodiments, channel 176 may be made of a corrosion resistant material (e.g., 304 stainless steel). Channel 176 can be heated to a high temperature. Channel 176 may also be open to hot formation fluids. Channel 176 can be processed to provide high emissivity. Channel 176 may have an upper section 230. In some embodiments, the upper section may be made of a material that is less resistant to corrosion than other parts of channel 176 (eg, carbon steel). Most of the upper section 230 may be located in the overburden 128 of the formation. The upper section 230 may be affected by temperatures the same as the temperature of the channel 176. In one embodiment, the channel 176 and the upper section 230 have a diameter of about 7.6 cm.

The conductor 174 can be placed in the channel 176. The part of the channel located near the conductor 174 can be made of metal, which has the desired electrical properties, emissivity, creep resistance and corrosion resistance at high temperatures. Conductor 174 may include, but is not limited to, stainless steel 310, stainless steel 304, stainless steel 316, stainless steel 347, and / or other steel and non-steel alloys. The conductor 174 may have a diameter of about 3 cm, however, the diameter of the conductor 174 may vary depending, but not limited to, heating requirements and power requirements. The conductor 174 may be located in the channel 176 using one or more centralizers 180. The centralizers 180 may be ceramic or a combination of ceramic and metal. Centralizers 180 may prevent the conductor 174 from coming into contact with channel 176. In some embodiments, centralizers 180 may be connected to conductor 174. In other embodiments, centralizers may be connected to channel 176. Conductor 174 may be electrically connected to channel 176 using a slider. 188.

Conductor 174 can be connected to adapter conductor 236. Adapter conductor 236 can be used as an electrical junction between lead conductor 232 and conductor 174. In one embodiment, adapter conductor 236 may be carbon steel. The junction conductor 236 may be connected to the junction conductor 232 by an electrical connector 242. FIG. 10 shows, on an enlarged scale, one embodiment of a junction of the junction conductor 236, the electrical connector 242, the insulator 240, and the lead wire 232. The lead wire 232 may include one or more conductors (e.g. three conductors). In some embodiments, one or more of the conductors may be insulated copper conductors (eg, rubber insulated copper cable). In some embodiments, one or more conductors may be an insulated or non-insulated stranded copper cable. As shown in FIG. 10, an insulator 240 may be located inside the lead conductor 232. The insulator 240 may include electrically insulating materials such as fiberglass. An insulator 240 may connect an electrical connector 242 to a heater support 228, as shown in FIG. 9. In one embodiment, an electric current may flow from a power source through a lead conductor 232, through a junction conductor 236 to a conductor 174, and return through channel 176 and the upper section 230.

As shown in FIG. 9, the heater support 228 may include a support that is used to install the heating section 226 in the hydrocarbon layer 116. For example, the heater support 228 may be a sucker rod that is introduced through the cover layer 128 from the earth's surface. The sucker rod may include one or more parts that can be connected to each other on the surface by introducing the rod into the formation. In some embodiments, heater support 228 is a single piece assembled in an assembly workshop. The introduction of the heater support 228 into the formation may cause the heating section 226 to be pushed into the formation.

The overburden casing 156 may be supported within the overburden 128 using reinforcing material 154. The reinforcing material may include cement (eg, Portland cement). The surface conductor 166 may surround the reinforcing material 154 and the casing 156 of the covering layer in part of the covering layer 128 near the earth's surface. Surface conductor 166 may include a surface casing.

11 shows an alternative embodiment of a conductor-type heater in a channel arranged substantially horizontally within the formation. In one embodiment, heater support 228 may be a low resistance conductor (eg, low resistance section 178 shown in FIG. 6). Heater support 228 may include carbon steel or other electrically conductive materials. Heater support 228 may be electrically connected to adapter conductor 236 and conductor 174.

In some embodiments, a heater may be located inside an open hole in a hydrocarbon containing formation. 12 schematically shows an embodiment of a conductor-type heater in a channel arranged substantially horizontally inside an open hole in the formation. The heating portion 226 may be located within the opening 114 in the hydrocarbon layer 116. In some embodiments, the heater support 228 may be a low resistance conductor (for example, low resistance section 178 shown in FIG. 6). The heater support 228 may be electrically connected to the adapter conductor 236 and the conductor 174. FIG. 13 shows an alternative embodiment of the conductor-in-channel heater shown in FIG. 12. In some embodiments, perforated casing 250 may be located in hole 114, as shown in FIG. 13. In some embodiments, centralizers 180 may be used to support the casing 250 within the bore 114.

In other embodiments of the heater, the heating section 226, as shown in FIGS. 9, 11 and 12, may be located in the wellbore with an orientation different from substantially horizontal in the hydrocarbon layer 116. For example, the heating section 226 may be located in the hydrocarbon layer 116 at an angle of about 45 ° or substantially vertically in the formation. In addition, heater elements located in the cover layer 128 (e.g., heater support 228, cover layer casing 156, upper section 230, etc.) may have an orientation other than substantially horizontal within the cover layer.

In some embodiments of the heater, the heater may be removably installed in the formation. Heater support 228 can be used to install and / or remove a heater, including heating section 226, from a formation. The heater may be removed for repair, replacement, and / or for using the heater in another well. The heater can be reused in the same layer or in different layers. In some embodiments, a heater or part of a heater may be wound on a pipe carriage and moved to another well.

In some embodiments of heating a hydrocarbon containing formation, it is possible to install more than one heater in a well or in a well of heating. The presence of more than one heater in the well allows the selected part or parts of the formation to be heated at a different rate than other parts of the formation. Having more than one heater in the well provides a backup heater in the well if one or more heaters fail. The presence of more than one heater in the well provides the ability to create a uniform temperature profile along the desired part of the well. The presence of more than one heater in the well provides the ability to quickly heat the hydrocarbon layer or layers from the ambient temperature to the pyrolysis temperature. More than one heater may include similar types of heaters, or may include various types of heaters. For example, more than one heater may be a heater in the form of a natural distributed furnace, a heater with an insulated conductor, a heater in the channel type, a heater with an elongated element, a downhole combustion chamber (for example, a downhole flameless combustion chamber or a downhole combustion chamber, etc.) .

On Fig shows an embodiment of a centralizer 180 located on the conductor 174. The disks 258 maintain the position of the centralizer 180 relative to the conductor 174. The disks 258 can be metal disks welded to the conductor 174. The disks 258 can be welded to the conductor 174 with a tack weld. On Fig shown in a top view an embodiment of the centralizer. Centralizer 180 may be made of any suitable electrically insulating material capable of withstanding high voltages at high temperatures. Examples of such materials include, but are not limited to, alumina and / or Macor. Centralizer 180 may electrically isolate conductor 174 from channel 176, as shown in FIGS. 14 and 15.

Heat can be generated inside an open well using a conductor-type channel heater. The generated heat can heat through radiation a portion of the hydrocarbon containing formation in the vicinity of a conductor-in-channel heater. To a lesser extent, due to the conductivity of the gas, part of the formation can be heated near the conductor-type heater in the channel. The use of an open well reduces the cost of casing and packaging associated with filling the hole with material to ensure heat transfer due to conductivity between the insulated conductor and the formation. Additionally, heat transfer due to radiation can be more efficient than heat transfer due to conductivity in the formation, so that heaters can operate at a lower temperature when using heat transfer due to radiation. Operating at a lower temperature extends the life of the heater and / or reduces the cost of the material needed to make the heater.

The conductor-type heater in the channel may be installed in the hole 114. In one embodiment, the conductor-type heater in the channel may be installed in sections in the well. For example, a first section of a conductor-type heater in a channel may be suspended in a well using a drilling rig. A section may have a length of about 12 m. A second section (for example, substantially the same length) may be connected to the first section in the well. The second section can be connected to the first section by welding and / or by means of a thread located on the first and second sections. An orbital welding machine located at the wellhead can weld the first section to the first section. The first section can be lowered into the well using a drilling rig. This process can be repeated with the following sections connected to the previous sections until a heater of a given length is placed in the well. In some embodiments, three sections can be welded together before being placed in the well. Welding points can be performed and tested before using the rig to attach three sections to a string already placed in the ground. Three sections can be lifted using a crane to the rig. The presence of already welded three sections reduces the installation time of the heater.

Assembling a heater in a location close to the formation (for example, at the site of the formation) may be more economical than transporting the preformed heater and / or channels to the hydrocarbon formation. For example, assembling a heater on a formation site can reduce the cost of transporting assembled heaters over long distances. Additionally, heaters can be more easily assembled at the site of the formation when changing lengths and / or changing materials in accordance with special requirements for the formation. For example, the part of the heater to be heated can be made of material (for example, stainless steel 304 or another high-temperature alloy), while the part of the heater in the coating layer can be made of carbon steel. The formation of the heater on site allows the heater to be made specifically for the hole in the formation, so that part of the heater in the overburden may be carbon steel, rather than a more expensive heat-resistant alloy. The length of the heater can be changed in accordance with changes in the depth of the layers of the reservoir and the properties of the reservoir. For example, the formation may have a varying thickness and / or may be located under rough terrain, an uneven surface, and / or may be a covering layer with a varying depth. Heaters with varying lengths and from various materials can be assembled at a site with a length depending on the depth of each hole in the formation.

On Fig shows an embodiment of the Assembly of the heater type conductor in the channel and install the heater in the reservoir. A conductor-type heater in a channel can be assembled in an assembly workshop 272. In some embodiments, a heater is assembled from channels transported to a formation site. In other embodiments, heaters can be made from stocks of plates that form into channels in an assembly workshop. An advantage of forming a channel in an assembly workshop is that the surface of the plates can be machined with the desired coating (e.g., a coating that provides the desired emissivity) or cladding (e.g., copper plating) before forming the channel so that the treated surface is the inner surface of the channel . In some embodiments, parts of the heater may be formed from plates in the assembly shop, while other parts of the heater are formed from channels transported to the formation site.

A separate conductor-type heater 274 in a channel may comprise a conductor 174 and a channel 176, as shown in FIG. In one embodiment, conductor 174 and channel 176 may be made of several sections connected together. In one embodiment, each section is a standard 40-foot (12.2 m) pipe section. Sections of other lengths may also be made and / or used. Additionally, sections of the conductor 174 and / or channel 176 can be processed in the assembly shop 272 before, during, or after processing. Sections can be processed, for example, in order to increase the emissivity of the sections by roughening and / or oxidizing the sections.

Each conductor type heater 274 in the channel can be assembled in an assembly workshop. The components of the conductor-type heater 274 in the channel may be located on or inside the conductor-type heater 274 in the channel in the assembly workshop. Components may include, but are not limited to, one or more centralizers, low resistance sections, sliders, insulating layers, cladding, or connecting materials.

As shown in FIG. 16, each individual conductor-type heater 274 in the channel can be connected to at least one separate conductor-type heater 274 in the channel at the connecting portion 278 to form a conductor-type heater 276 in the channel of a desired length. The desired length may be, for example, the length of the conductor-type heater in the channel required for the selected hole in the formation. In some embodiments, connecting a separate conductor-type heater 274 to the channel with at least one additional separate conductor-type heater 274 includes welding a separate conductor-type heater in the channel with at least one additional separate conductor-type channel heater. In one embodiment, the welding of each individual conductor-type heater 274 in a channel with an additional separate conductor-type heater in a channel is performed by forging two adjacent sections with each other.

In some embodiments, sections of the welded heater type 276, the conductor in the channel of the desired length are placed on the desktop, holding tray or in the hole in the ground, until the length of the heater is complete. The integrity of the weld can be checked as each weld is completed. For example, the integrity of a weld can be verified by non-fracture testing methods such as X-ray test, acoustic test and / or electromagnetic test. After the full length of the conductor type heater 276 in the channel of the desired length can be wound, it can be wound around the reel 282 in the direction of arrow 284. The coiling of the conductor type heater 276 in the channel of the desired length allows easier transport to the hole in the formation. For example, a conductor type heater 276 in a channel of a desired length can be more easily transported by tractor or train to a hole in the formation.

In some embodiments, a set of conductor-in-channel heaters welded together can be wound onto a coil 282, while other sections are formed on a connecting portion 278. In some embodiments, the assembly workshop may be mobile equipment (for example, located on one or more tractors or semi-trailers) that can be moved to the hole in the formation. After supplying the welded conductor type heater in the total length channel with components (for example, centralizers, coatings, claddings, sliders), the conductor type heater in the full length channel can be lowered into the hole in the formation.

In some embodiments, a conductor type heater 274 in a channel of a desired length can be tested in test section 280 before reeling up the heater. Test section 280 may be used to test the entire conductor heater 276 in a channel of a desired length or sections of a conductor heater in a channel of a desired length. Test section 280 can be used to test selected properties of a conductor heater 276 in a channel of a desired length. For example, test section 280 can be used to test properties, such as, but not limited to, electrical conductivity, weld integrity, thermal conductivity, emissivity, and mechanical strength. In one embodiment, test section 280 is used to test the integrity of the welds using weld verification technology using electromagnetic acoustic radiation (EMAT).

A conductor type heater 276 in a channel of a desired length can be wound around a reel 282 for transportation from an assembly hall 272 to an opening in the formation. In one embodiment, an assembly shop 272 is located at a formation site. For example, the assembly shop may be part of the surface equipment used to process fluids from the formation, or may be located near the formation (for example, less than about 10 km from the formation, in some embodiments, less than about 20 km or less than about 30 km) . Other types of heaters (for example, insulated conductor heaters, naturally distributed heaters) can also be assembled in an assembly workshop 272. These other heaters can also be wound onto a coil 282, transported to a hole in a formation, and installed in a hole, as described for heater 276 type conductor in the channel of the desired length. In some embodiments, coil 282 may be part of a pipe-wound rig (e.g., an insulated conductor heater or a conductor-in-channel heater).

The transportation of the conductor type heater 276 in a channel of a desired length to the hole in the formation is represented by arrow 286 in FIG. 16. Transporting a conductor heater 276 in a channel of a desired length may include transporting the heater on a platform, trailer, tractor truck or train, or in a pipe winding unit. In some embodiments, more than one heater may be located on the platform. Each heater can be installed in a separate hole in the formation. In one embodiment, a rail system (e.g., for a train) may be laid to transport heaters from assembly plant 272 to each of the openings in the formation. In some cases, a lifting and moving system may be used in which the rails for a train, after being used in one place, are lifted and moved to another place.

After transporting the coil 282 with a conductor heater 276 in the channel of the desired length to the hole 114, the heater can be reeled up and installed in the hole in the direction of arrow 288. The conductor heater 276 in the channel of the desired length can be coiled from the coil 282 while the coil is on the platform tractor or train. In some embodiments, it is possible to install more than one conductor type heater 276 at a time in a channel of a desired length. In one embodiment, more than one heater can be installed in one hole 114. Coil 282 can be reused for additional heaters after installing a conductor heater 276 in a channel of a desired length. In some embodiments, coil 282 can be used to remove a conductor type heater 276 in a channel of a desired length from the hole. A conductor heater 276 in a channel of a desired length can again be wound on a coil 282 when the heater is removed from a hole 114. After that, a conductor heater 276 in a channel of a desired length can be reinstalled from a coil 282 in a hole 114 or transported to another hole in the formation and installed in another hole.

In some embodiments, a conductor-type heater 276 in a channel of a desired length, or any heater (for example, an insulated-conductor heater or a heater in the form of a naturally distributed furnace) can be installed to remove from opening 114. The heater can be removed for repair or replacement if the heater is out out of order or broken. In other cases, the heater may be removed from the hole and transported for installation in another hole in the formation (or in another formation) at a later time. In still other cases, the heater may be removed and replaced with a cheaper heater in later stages of heating. The ability to remove, replace and / or relocate the heater may be preferred to reduce the cost of equipment and / or operation. In addition, the ability to remove and replace an inefficient heater can eliminate the need for well formation in the immediate vicinity of existing wells that have failed heaters in a heated or heated formation.

In some embodiments, a channel of a desired length may be placed in a hole 114 before placing a conductor of a desired length. The conductor and the channel of the desired length can be assembled in the assembly shop 272. The channel of the desired length can be installed in the hole 114. After installing the channel of the desired length in the hole 114, you can install the conductor of the desired length. In one embodiment, a channel and conductor of a desired length are wound onto a coil in an assembly workshop 272 and wound from a coil for installation in hole 114. Components (eg, centralizers, sliders, etc.) can be placed on a conductor or channel when the conductor is inserted into the channel and hole 114.

In some embodiments, the centralizer 180 may have at least two parts connected to each other to form a centralizer (for example, a centralizer with a clamping shell). In one embodiment, the parts are placed on the conductor and connected to each other when the conductor is inserted into a channel or hole. Parts can be connected using fasteners, such as, but not limited to, clamps, bolts, screws, latches and / or glue. The parts may be shaped such that the first part is included in the second part. For example, one end of the first part may have a slightly smaller width than the end of the second part, so that both ends are located one above the other when connecting the two parts.

In some embodiments, the low resistance section is connected to a conductor heater 276 in a channel of the desired length in the assembly workshop 272. In other embodiments, the low resistance section is connected to a conductor heater 276 in a channel of the desired length after installing the heater in the hole 114. The low resistance section is desired lengths can be assembled in assembly shop 272. The assembled low-resistance conductor can be wound around a reel. The assembled low resistance conductor can be unwound from the coil and connected to the heater type 276 in the channel of the desired length after installing the heater in the hole 114. In another embodiment, the low resistance section is assembled when the low resistance conductor is connected to the heater type 276 in the channel of the desired length and installed into the hole 114. A conductor heater 276 in a channel of a desired length can be connected to the support after installation, so that the low resistance section is connected to the mouth copulating heater.

Assembling the desired length of the low resistance conductor may include connecting the individual low resistance heaters to each other. The individual low resistance conductors may be plate conductors obtained from the manufacturer. The individual low-resistance conductors can be connected to an electrically conductive material to lower the electrical resistance of the low-resistance conductor. The electrically conductive material can be connected to a separate low resistance conductor before assembling the desired length of the low resistance conductor. In one embodiment, the individual low resistance conductors may have threaded ends that connect to each other. In another embodiment, the low resistance conductors may be shaped such that one end of the first individual low resistance conductor enters the end of the second individual low resistance conductor. For example, one end of the first separate low resistance conductor can be made in the form of a socket, while one end of the second separate low resistance conductor is a pin made end.

In another embodiment, a conductor-type heater in a channel of a desired length can be assembled at a well (or hole) in a formation and installed in a well when assembling a conductor-type heater in a channel. The individual conductors can be connected to form the first part of the conductor of the desired length. In a similar manner, channels can be connected to form a first channel section of a desired length. The first formed sections of the conductor and channel can be installed in the well. The first formed sections of the conductor and channel can be electrically connected at the first end, which is installed in the well. The first sections of the conductor and the channel can in some embodiments be connected essentially simultaneously. Additional sections of the conductor and / or channel can be formed during or after the installation of the first formed sections. Additional sections of the conductor and / or channel can be connected to the first formed sections of the conductor and / or channel and installed in the well. Centralizers or other components can be connected to sections of the conductor and / or channel and installed with the conductor and channel into the well.

In one embodiment, the elongated member may be located within an opening (eg, an open well) in a hydrocarbon containing formation. The hole may be an open hole in the hydrocarbon containing formation. The elongated element may be a piece of metal (strip) or any other elongated piece of metal (for example, a rod). The elongated element may include stainless steel. The elongated element may be made of a material capable of resisting corrosion at high temperatures inside the hole.

The elongated element may be an open metal heater. "Open metal" refers to a metal that does not have a layer of electrical insulation, such as mineral insulation, which provides electrical insulation for the metal within the operating temperature range of the elongated element. The exposed metal may comprise a metal that includes a corrosion inhibitor, such as a naturally occurring oxide layer, a supported oxide layer and / or film. Open metal includes metal with polymer or other type of electrical insulation that cannot maintain insulating properties at the normal operating temperature of an elongated element. Such material may be placed on the metal and may be thermally destroyed during use of the heater.

An elongated element can have a length of about 650 m. Larger lengths can be achieved using sections of stronger alloys, however, such elongated elements can be expensive. In some embodiments, the elongated member may rest on a plate in the well. The elongated element may include sections of various conductive materials that are welded to each other end to end. You can use a large amount of electrically conductive welding material to connect the individual sections with each other to increase the strength of the obtained element and to provide a path of electricity that does not lead to the formation of an electric arc discharge and / or corrosion in welded joints. In some embodiments, the various sections can be welded to each other using blacksmithing. Various conductive materials may include alloys with high flow resistance. Sections of different conductive materials may have different diameters to ensure uniform heating along the elongated element. The first metal, which has a higher flow resistance than the second metal, usually has a higher electrical resistivity than the second metal. The difference in resistivity allows a section with a larger cross-sectional area of a creep-resistant first metal to dissipate the same amount of heat as a section with a smaller cross-sectional area of the second metal. The cross-sectional areas of two different metals can be selected so as to provide substantially the same amount of dissipated heat in two sections of metals welded together. Conductive materials may include, but are not limited to, Inconel 617, HR-120, 316 stainless steel, and 304 stainless steel. For example, the elongated element may have a 60 m long Inconel 617 section, a 60 m long HR-120 section, and a stainless steel 304 with a length of 150 m. In addition, the elongated element may have a low resistance section that can extend from the wellhead through the overburden. This low resistance section may reduce heating within the formation from the wellhead through the overburden. The low resistance section may be the result of, for example, selection of an electrically conductive material and / or an increase in the cross-sectional area available for electrical conductivity.

In one embodiment of the heater, the support member may extend through the overburden and the elongated member or open metal members may be coupled to the support member. A plate, centralizer or other type of support element may be located near the interface between the overburden and the hydrocarbon layer. A low resistance cable, such as a stranded copper cable, may extend along the support member and may be connected to an elongated member or members. A low resistance cable can be connected to a power source that supplies electrical energy to the elongated element or elements.

On Fig shows an embodiment of several elongated elements that can heat the hydrocarbon containing formation. Two or more (eg, four) elongated members 300 may be supported by the support member 304. The elongated members 300 may be connected to the support member 304 using insulated centralizers 302. The support member 304 may be a pipe or duct. The support member 304 may also be a perforated pipe. The support member 304 may provide an oxidizing fluid flow to the bore 114. The support member 304, elongated members 300, and insulated centralizers 302 may be located in the bore 114 in the hydrocarbon layer 116. The insulated centralizers 302 maintain the position of the elongated members 300 on the support member 304, so that lateral movement of elongated elements 300 at temperatures high enough to deform the support element 304 or elongated elements 300. The elongated elements 300 in some embodiments may l metal strips of stainless steel with a width of about 2.5 cm and a thickness of about 0.3 cm. Electric current can be supplied to the elongated elements 300 so that the elongated elements 300 generate heat due to electrical resistance.

The elongated elements 300 can be connected electrically in series. Electric current can be supplied to the elongated elements 300 using the lead wire 150. The lead wire 150 can be connected to the wellhead 152. Electric current can be returned to the wellhead 152 using a lead-in conductor 308 connected to elongated elements 300. The lead-in conductor 150 and the lead-out conductor 308 can be connected to the wellhead 152 on the surface 130 through a sealing flange located between the wellhead 152 and the overburden 128 The sealing flange may prevent fluid from flowing out of opening 114 onto surface 130 and / or into the atmosphere. The lead-in conductor 150 and the lead-out conductor 308 can be connected to the elongated elements 300 using an adapter conductor with cold pins. The lead-in conductor 150 and the lead-out conductor 308 can be made of low-resistance conductors, so that when an electric current passes through the lead-in conductor 150 and the lead-out conductor 308, essentially no heat is generated.

In some embodiments, the overburden casing 156 may be placed in reinforcing material 154 in the overburden 128. In other embodiments, the casing may not be cemented into the formation. Surface conductor 166 may be located in reinforcing material 154. Support member 304 may be coupled to wellhead 152 on surface 130. Centralizers 180 may maintain the position of support member 304 within the liner casing 156. Electric current can be supplied to elongated elements 300 to generate heat. The heat generated by the elongated elements 300 may be radiated inside the opening 114 for heating at least a portion of the hydrocarbon layer 116.

The oxidizing fluid may be supplied along the length of the elongated elements 300 from the oxidizing fluid source 120. Oxidizing fluid may inhibit carbon deposition on or near elongated elements. For example, an oxidizing fluid can react with hydrocarbons to form carbon dioxide. Carbon dioxide can be removed from the hole. Holes 306 in support member 304 may provide an oxidizing fluid flow along the length of elongated members 300. Holes 306 may be critical flow holes. In some embodiments, a conduit for controlling pressure in the formation and / or for introducing oxidizing fluid into the hole 114 may be located adjacent to the elongated members 300. Without the flow of the oxidizing fluid, carbon may settle on or near the elongated members 300 or on isolated centralizers 302. Carbon deposits may cause a short circuit between the elongated elements 300 and the insulated centralizers 302 or hot spots along the elongated elements 300. The oxidizing fluid can be used to reacting with carbon in the formation. The heat generated by the reaction with carbon can complement or maintain the heat generated by electricity.

The underground pressure in the hydrocarbon containing formation may correspond to the pressure of the fluid generated within the formation. Heating hydrocarbons within a hydrocarbon containing formation may create fluids through pyrolysis. Created fluids can evaporate inside the formation. Vapors and pyrolysis reactions can increase pressure inside the formation. Fluids that increase pressure include, but are not limited to, fluids formed during pyrolysis and water that evaporates during heating. As the temperature inside the selected section of the heated portion of the formation rises, the pressure inside the selected section may increase as a result of increased fluid generation and water evaporation. Controlling the rate of fluid removal from the formation provides the ability to control pressure in the formation.

In some embodiments, the pressure inside the selected section of the heated portion of the hydrocarbon containing formation may vary depending on factors such as depth, distance from the heat source, hydrocarbon productivity within the hydrocarbon containing formation, and / or distance from the production well. The pressure inside the formation can be determined in several different places (for example, near or in production wells, near or in heat sources, or in monitoring wells).

Heating a hydrocarbon containing formation to a pyrolysis range can occur before significant permeability is created within the hydrocarbon containing formation. An initial lack of permeability may prevent the transportation of generated fluids from the pyrolysis zone within the formation to the production well. When the heat is initially transferred from the heat source to the hydrocarbon containing formation, the pressure of the fluids within the hydrocarbon containing formation may increase near the heat source. Such an increase in fluid pressure can lead to fluid generation during the pyrolysis of at least some hydrocarbons in the formation. Elevated fluid pressure can be vented, monitored, modified and / or controlled by a heat source. For example, the heat source may include a valve that allows some fluid to be removed from the formation. In some embodiments of the heater, the heater may include an open hole configuration that prevents pressure damage to the heater.

In one embodiment of the in-situ conversion process, the pressure within the selected section of the portion of the hydrocarbon containing formation may be increased to the selected pressure during pyrolysis. The selected pressure may be within a range of about 2 bar (absolute value) to about 72 bar (absolute value) or, in some embodiments, from about 2 bar (absolute value) to 36 bar (absolute value). Alternatively, the selected pressure may be within a range of from about 2 bar (absolute value) to about 18 bar (absolute value). In some embodiments of the in-situ conversion process, most hydrocarbon fluids can be produced from a formation having a pressure in the range of from about 2 bar (absolute value) to about 18 bar (absolute value). The pressure during pyrolysis may vary or may vary. The pressure can be changed to change and / or control the composition of the produced fluids of the formation, to control the percentage of the condensed fluid compared to the non-condensed fluid, and / or to control the density of the API of the produced fluid. For example, a decrease in pressure can lead to a higher content of condensed fluid. Condensable fluid may have a higher percentage of olefins.

In some embodiments of the in-situ conversion process, increased pressure due to fluid generation can be maintained within the heated portion of the formation. Maintaining increased pressure within the formation may inhibit subsidence of the formation during in-situ conversion. Increased formation pressure can help create high-quality products during pyrolysis. Increased formation pressure may facilitate production of vapor phase fluids from the formation. Mining of the vapor phase reduces the size of the collector channels used to transport the fluids extracted from the reservoir. Increased formation pressure can reduce or eliminate the need to compress formation fluids on the surface in order to transport fluids through the collector channels to surface equipment. Maintaining high pressure within the formation can also facilitate the generation of electricity using produced non-condensing fluid. For example, produced non-condensing fluid can be passed through a turbine to generate electricity.

The increased pressure in the formation can also be maintained in order to produce more fluids and / or higher quality fluids from the formation. In some in-situ conversion process embodiments, significant amounts (eg, most) of the hydrocarbon fluids produced from the formation may be non-condensable hydrocarbons. The pressure can be selectively increased and / or maintained within the formation to allow formation of shorter chain hydrocarbons in the formation. The formation of small chain hydrocarbons in the formation allows the production of more non-condensable hydrocarbons from the formation. Condensable hydrocarbons produced from the formation at a higher pressure may have higher quality (e.g. API density) than condensed hydrocarbons produced from the formation at a lower pressure.

Increased pressure can be maintained within the heated portion of the hydrocarbon containing formation to prevent the production of formation fluids having fewer carbon atoms, for example, about 25. Some compounds with a large number of carbon atoms can be entrained by the vapor in the formation and removed from the formation together with the steam. High pressure in the formation may prevent steam entrainment of compounds with a large number of carbon atoms and / or polycyclic hydrocarbon compounds. Increased pressure within the hydrocarbon containing formation may increase the boiling point of the fluid within the formation. Compounds with a large number of carbon atoms can remain in the liquid phase in the formation for significant periods of time. Significant time intervals can provide sufficient time for the pyrolysis of compounds to form compounds with fewer carbon atoms.

Maintaining increased pressure inside the heated portion of the formation may unexpectedly provide the production of large quantities of high quality hydrocarbons. Maintaining high pressure can facilitate vapor transport of pyrolysis fluids within the formation. The increase in pressure often provides for the production of hydrocarbons with a lower molecular weight, since such hydrocarbons with a lower molecular weight are more easily transported in the vapor phase in the reservoir.

We can assume that the creation of hydrocarbons with a lower molecular weight (and, correspondingly, increased transport of the vapor phase) is a consequence of the partially spontaneous formation and reaction of hydrogen inside a part of the hydrocarbon containing formation. For example, maintaining high pressure can force the hydrogen created during pyrolysis into the liquid phase (for example, by dissolution). Heating a portion of the formation to a temperature within the pyrolysis temperature range can lead to pyrolysis of hydrocarbons within the formation to form pyrolysis fluids in the liquid phase. Created components may include double bonds and / or radicals. H ₂ in the liquid phase can restore double bonds of the created pyrolysis fluids, thereby reducing the possibility of polymerization or the formation of long-chain compounds from the created pyrolysis fluids. In addition, hydrogen can also neutralize radicals in the formed pyrolysis fluids. Therefore, H ₂ in the liquid phase can inhibit the reaction of the formed pyrolysis fluids with each other and / or with other compounds in the formation. Short-chain hydrocarbons can go into the vapor phase and can be mined from the reservoir.

Performing the in-situ conversion process at elevated pressure can provide for the production of formation fluid in the vapor phase. Vapor phase mining can provide enhanced removal of lighter (and higher quality) pyrolysis fluids. Vapor phase production can result in fewer fluids remaining in the formation after fluid generation by pyrolysis. Vapor phase production results in fewer production wells in the formation than is currently used for producing the liquid phase and / or liquid and vapor phase. Fewer production wells significantly reduce the costs associated with performing an in-situ conversion process.

In one embodiment, a portion of the hydrocarbon containing formation may be heated to increase the partial pressure of H ₂ . In some embodiments, the increased partial pressure of H ₂ may include partial pressures of H ₂ in the range of from about 0.5 bar to about 7 bar. Alternatively, the range of increased partial pressure of H ₂ may include partial pressures of H ₂ in the range from about 5 bar to about 7 bar. For example, most hydrocarbon hydrocarbons can be produced with a partial pressure of H ₂ within a range of from about 5 bar to about 7 bar. The range of partial pressures H ₂ within the range of partial pressures H _{2 of} pyrolysis can vary depending, for example, on the temperature and pressure of the heated part of the formation.

Maintaining the partial pressure of H ₂ within the formation above atmospheric pressure can increase the API densities of produced condensed hydrocarbon fluids to more than about 25 ° or, in some cases, more than about 30 °. Maintaining an increased partial pressure of H ₂ inside the heated portion of the hydrocarbon containing formation may increase the concentration of H ₂ within the heated portion. H ₂ may be available for reaction with pyrolyzed hydrocarbon components. The reaction of H ₂ with pyrolyzed hydrocarbon components can reduce the polymerization of olefins to bitumen and other crosslinked products that are difficult to improve quality. Therefore, production of hydrocarbon fluids having low API densities may be prohibited.

The control of pressure and temperature within the hydrocarbon containing formation may control the properties of the produced formation fluids. For example, the composition and quality of formation fluids produced from the formation can be changed by changing the average pressure and / or average temperature in a selected section of the heated portion of the formation. The quality of the produced fluids can be estimated based on the characteristics of the fluid, such as, but not limited to, API density, percentage of olefins in produced fluids of the formation, ratio of ethene to ethane, atomic ratio of hydrogen to carbon, percentage of hydrocarbons in produced fluids of the formation having a number more than 25 carbon atoms, total equivalent production (gas and liquid), total production of liquids and / or liquid yield as a percentage in the Fisher analysis.

In light of this description, additional modifications and alternative embodiments of various aspects of the invention may be apparent to those skilled in the art. In accordance with this, this description should be considered only as an illustration for the purpose of demonstrating to specialists in this field of technology the General principle of the invention. It should be noted that the shown and described embodiments of the invention should be considered as currently preferred embodiments. Elements and materials can be replaced by the shown and described elements and materials, parts and processes can be performed in the reverse order, and some features of the invention can be used independently, as is obvious to specialists in this field of technology based on this description. You can make changes to the described elements without departing from the idea and scope of the invention presented in the following claims. Additionally, it should be noted that those described as independent features may be combined in certain embodiments.

Claims (20)

1. A system configured to heat at least a portion of a hydrocarbon containing formation (116), comprising a heater configured to be placed in a well in the formation and removed to transfer heat from the heater to a part of the formation (116) for pyrolysis, at least some hydrocarbons in the reservoir (116), characterized in that the heater is a heater (140, 168, 174, 176) of the type of electrical conductor in the pipe, which is configured to install and / or extract from an open or open hole (114) using a coil (282) or an installation / removal system with coiled pipes, wherein the heater (140, 168, 174, 176) of the type electric conductor in the pipe can again be used in at least one alternative open or open section (114) of the well in the reservoir (116). 2. The system according to claim 1, in which the open or uncased portion (114) of the well has a diameter of at least about 5 cm, or at least about 7 cm, or at least about 10 cm, and however, the system is configured to enter an open or open hole section (114) of the well. 3. The system according to claim 1 or 2, in which the heater (140, 168, 174, 176) is configured to be removed from the well to repair the heater or to replace the heater with another heater. 4. The installation method of the system according to any one of claims 1 to 3 in the hydrocarbon containing formation, characterized in that it contains the arrangement of at least a portion of the heater (140, 168, 174, 176) of an electric conductor type in a pipe in an open or uncased portion (114) of the well in a hydrocarbon containing formation (116) by coiling at least a portion of the heater (140, 168, 174, 176) of the type of electric conductor in the pipe of the system from the coil and then placing at least part of the coiled heater (140, 168, 174, 176) of the type of electric conductor in the pipe in an open or open hole section (114) of the well. 5. The method according to claim 4, further comprising connecting at least one low resistance conductor to a heater (140, 168, 174, 176) of the type electric conductor in the pipe, wherein at least one low resistance conductor is made with the possibility of placement in the overburden (128) of the formation. 6. The method according to claim 5, further comprising assembling at least a portion of a heater (140, 168, 174, 176) of the type of electrical conductor in the pipe in a place near or adjacent to the hydrocarbon containing formation (116). 7. The method according to claim 5, further comprising winding at least a portion of the heater (140, 168, 174, 176) of the type of electrical conductor in the pipe to a coil (282). 8. The method according to claim 5, further comprising removing at least a portion of the heater (140, 168, 174, 176) of the type of electrical conductor in the pipe system from an open or open hole section (114) of the well by re-winding at least parts (140, 168, 174, 176). 9. The method according to claim 5, further comprising winding and / or unwinding the heater (140, 168, 174, 176) from the coil (282). 10. The method according to claim 5, further comprising transporting the heater (140, 168, 174, 176) on a trolley or train from the assembly site to an open or open hole section (114) of the well in the hydrocarbon containing formation (116). 11. The method according to claim 10, in which the cart or train can be additionally used to transport more than one heater (140, 168, 174, 176) to more than one open or open hole section (114) of the well in the hydrocarbon containing formation (116). 12. The method according to any one of claims 4-11, further comprising removing the heater (140, 168, 174, 176) from the open or open hole section (114) of the well in the formation (116) to check and / or repair the heater (140, 168 , 174, 176) and re-installing the heater in an open or open hole section (114) of the well, to relocate the heater (140, 168, 174, 176) in at least one alternative open or open hole section (114) of the well in the formation ( 116) or to replace at least a portion of the heater (140, 168, 174, 176). 13. A method of in situ treatment of at least a portion of a hydrocarbon containing formation (116) comprising providing heat from one or more heaters configured to be extracted, located in one or more wells in the formation (116), for at least one part of the formation (116); providing heat transfer from one or more heaters to a part of the formation (116); and the production of a mixture from the reservoir (116), characterized in that at least one heater (140, 168, 174, 176) of the type of electrical conductor in the pipe, which is configured to install and / or remove from an open or open hole (114 ) wells using a coil (282) or an installation / removal system with wound pipes, while (140, 168, 174, 176) type electric conductor in the pipe can be used in at least one alternative open or uncased section ( 114) wells in the reservoir (116). 14. The method according to item 13, further comprising maintaining the temperature inside at least part of the formation (116) within the pyrolysis temperature range with a lower pyrolysis temperature of about 250 ° C and an upper pyrolysis temperature of about 400 ° C. 15. The method of claim 13, further comprising heating at least a portion of the formation (116) to substantially pyrolyze at least some hydrocarbons within the formation (116). 16. The method according to item 13, further comprising controlling pressure and temperature inside at least most of the formation (116), the pressure being controlled as a function of temperature, or the temperature is controlled as a function of pressure. 17. The method according to item 13, in which the heat transfer from one or more heaters (140, 168, 174, 176) to part of the reservoir contains heat transfer essentially using thermal conductivity. 18. The method according to item 13, in which the produced mixture contains condensable hydrocarbons having a density in degrees of the American Petroleum Institute of at least about 25 °. 19. The method according to item 13, further comprising controlling pressure within at least most of the formation, wherein the controlled pressure is at least 2.0 bar (absolute value). 20. The method according to item 21, further comprising controlling the conditions inside the formation so that the produced mixture has a partial pressure of H ₂ inside the mixture of more than about 0.5 bar. Priority: 10.24.2001 according to claims 1-20

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