RU2597303C1 - Method of high-viscosity oil and bitumen deposits development - Google Patents

Abstract

FIELD: oil industry.

SUBSTANCE: invention relates to oil and gas industry and is intended for development of high-viscosity oil and bitumen deposits by heating. Technical result is increase of efficiency of deposit heating, increased coverage of deposit heating, higher volumes of extraction of oil and bitumen, reliability of the method. Method of high-viscosity oil and bitumen deposit development includes drilling of two process wells and one production well with horizontal shafts, installation of electrodes in horizontal shafts of process wells, connection of electrodes to electric substation at wellhead, placing of electric centrifugal pump in the horizontal shaft of production well, heating of the deposit with electric current with the help of electrodes installed in horizontal shafts of process wells, extraction of heated oil and bitumen from deposit by electric centrifugal pump from horizontal shaft of production well. Initially at least one production well and one heating well with horizontal shafts are drilled arranged in parallel to each other at distance of 15 m. Then in the upper horizontal shaft of the heating well hydraulic fracturing is performed with formation of longitudinal cracks and attachment of current-conducting material. Then, perpendicular to the initial section of horizontal shaft of heating well first process well with horizontal shaft is drilled, and perpendicular to the end section of horizontal shaft of the heating well second process well with horizontal shaft is drilled, wherein, horizontal shafts of process wells are placed within the limits of cracks of hydraulic fracturing of formation. Then between process wells parallel to their vertical shafts and perpendicular to their horizontal shafts of heating and production wells two additional production wells are drilled. Horizontal shafts of additional production wells are arranged in parallel and between the upper and lower horizontal shafts of heating and production wells. Pump string rods are used as electrodes. Lower horizontal shaft of production well and horizontal shafts of the additional production wells are equiped with electric-centrifugal pumps. Deposit is heated by means of upper horizontal shaft of heating well, and heated oil and bitumen are extracted by electric centrifugal pumps through the lower horizontal shaft of production well and horizontal shafts of additional production wells.

EFFECT: proposed method of development increases efficiency of heating of high-viscosity oil and bitumen, simplifies technological process of method implementation, increases coverage of deposit heating, increases volume of heated oil and bitumen extraction, reliability of method implementation.

1 cl, 2 dwg

Description

The proposal relates to the oil and gas industry and is intended for the development of deposits of high viscosity oil and bitumen by heating.

A known method of developing deposits of highly viscous oil and bitumen (Vakhitov G.G., Simkin E.M. Use of physical fields to extract oil from the reservoirs. - M .: Nedra, 1985, p. 192-194), including the impact of an electric field on the reservoir through the wells.

The disadvantage of this method is the low efficiency of the development of deposits of highly viscous oil and bitumen due to insufficient coverage of the formation by an electric field and heating.

A known method of developing deposits of highly viscous oil and bitumen (patent RU No. 2418163, IPC E21B 43/24, publ. 05/10/2011, bull. No. 13), including the construction of a well with an underground capacity, opening the formation with horizontal wells, the mouth of which is tied through remotely controlled valves and a collector with an underground reservoir, heating the reservoir, collecting products in the underground reservoir and pumping them to the surface with pumps, while heating the reservoir to bring its products to a fluid state is carried out by the combined action of electromagnetic and acus fields created by emitters placed in horizontal wells with the possibility of periodic movement and connected through wellhead seals and corresponding transmission lines inside the well with ground-based generators of high-frequency and acoustic vibrations, and heating of the formation sections begins according to the accepted production technology from the mouth of horizontal wells to the bottom for associated subsequent warming up of unheated fields of the reservoir with the heat of the flowing product, the optimum temperature of which they are achieved by controlling the flow rate by remotely controlled valves, while the production of the formation in the gravitational mode and under the influence of reservoir pressure enters the underground tank, and pumps for pumping the products are placed in an additional well connected to the ground-based system for trapping light fractions and perforated in the zone of the underground tank, generators of high-frequency and acoustic vibrations are placed in the formation zone in the well, and wells are being built at the field under development, covering its entire area, and oyaniya therebetween selected lengths more double horizontal wells.

The disadvantages of the method are:

- firstly, a complex process of implementing the method;

- secondly, the high cost of implementing the method associated with the use of a large number of technological equipment (ground-based generators of high-frequency and acoustic vibrations, emitters, underground tanks, etc.) and the construction of an additional well. These costs increase the cost of oil production;

- thirdly, a small thermal exposure of the reservoir and, as a result, low coverage and oil recovery coefficients of the highly viscous oil and bitumen deposits.

The closest in technical essence is the method of developing deposits of highly viscous oil and bitumen (patent RU No. 2085715, IPC E21B 43/24, publ. 07/27/1997, bull. No. 21), including drilling the deposits with two production wells and a production well with horizontal trunks directed parallel to each other, while electrodes are installed in the horizontal wells of the technological wells, and electrodes are connected to the high-frequency installation at the wellhead, and the electric centrifugal pump is lowered into the horizontal well of the producing well double-acting action, the reservoir is heated by electric current using the electrodes installed in the horizontal boreholes of the technological wells — the anode and cathode; after the reservoir is warmed up, the heated products from the horizontal well of the producing well are sent to the part of the reservoir not covered by the electric field, followed by pumping out of the heated oil pump to the daytime surface.

The disadvantages of the method are:

- firstly, the low efficiency of heating a deposit with electric current generated by a high-frequency installation, due to the spot electrodes heating a limited area of the reservoir in the initial section (from the mouth side) of a horizontal well to obtain a limited volume of heated products, and then pumping this volume of heated products with a reversible pump perforations made in the final section (from the bottom side) of horizontal wells in order to heat the reservoir with highly viscous ty and bitumen on the faces of horizontal wells. In addition, all this complicates the process of implementing the method;

- secondly, a small coverage (10-12 m) of the deposit by heating with an electric field in the initial section of the horizontal well and even less coverage (5-6 m) of the deposit by heating the heated products in the final section of the horizontal well and, as a result, uneven heating of the deposit, leading to low oil recovery deposits of highly viscous oil and bitumen;

- thirdly, the low volumes of extraction (flow rate) of heated oil and bitumen from production wells during the development of the deposit are due to the fact that before the selection, the heated products raised to the surface are pumped back into the reservoir with the aim of warming them up, where they manage to partially cool down and are not taken back ;

- fourthly, the low reliability of the implementation of the method, since it is necessary to use pumps of a special design for reversing products in the well, which will work in adverse horizontal conditions, and a large amount of expensive pumping equipment will be required to develop the entire deposit.

The technical objectives of the invention are to increase the efficiency of heating deposits of highly viscous oil and bitumen, simplifying the process of implementing the method, increasing the coverage of deposits by heating, increasing the selection of heated oil and bitumen and increasing the reliability of the method.

The stated technical problems are solved by the method of developing a highly viscous oil and bitumen deposit, including drilling the deposits with two technological wells and a producing well with horizontal shafts, installing electrodes in horizontal shafts of technological wells, connecting electrodes to an electrical substation at the wellhead, and launching an electric centrifugal pump into the horizontal well of a producing well , heating deposits with electric current using technological s installed in horizontal trunks bore holes of electrodes, selection of heated oil and bitumen from a deposit by an electric centrifugal pump from a horizontal wellbore of a producing well.

It is new that at least one production and one heating well is drilled with horizontal shafts located parallel and one below the other at a distance of 15 m, then a hydraulic fracturing of the formation is made in the upper horizontal well of the heating well with the formation of a longitudinal crack followed by its fastening with conductive material, then perpendicular to the initial section of the horizontal well of the heating well, drill the first production well with a horizontal well ohm, and perpendicular to the end portion of the horizontal well of the heating well, a second technological well is drilled with a horizontal well, the horizontal wells of technological wells being placed within the hydraulic fractures, then between the technological wells parallel to their vertical wells and perpendicular to the horizontal wells, two pairs of heating and producing wells are drilled additional production wells, horizontal shafts of additional production wells They run parallel to and between the upper and lower horizontal shafts of the heating and production wells, pump rods are used as electrodes lowered into the well, the lower horizontal well of the producing well and the horizontal shafts of additional producing wells are equipped with electric centrifugal pumps, and the deposits are heated using the upper horizontal well a heating well, and the selection of heated oil and bitumen is carried out using electric centrifugal pumps through the lower horizon ny barrel production well and horizontal trunks of additional production wells.

In FIG. 1 and 2 depict diagrams of the proposed method for developing deposits of high viscosity oil and bitumen.

The method of developing deposits of high viscosity oil and bitumen is implemented as follows.

In reservoir 1 (see FIGS. 1 and 2) of highly viscous oil and bitumen at a distance of, for example, 50 m from each other, pairs of heating 2 ′, 2 ″, 2 ″ ′, ... 2 ⁿ and producing 3 ′, 3 ″ are drilled , 3 ″ ′, ... 3 ⁿ wells with parallel horizontal shafts 4 ′, 4 ″, 4 ″ ′, ... 4 ⁿ and 5 ′, 5 ″, 5 ″ ’, ... 5 ^n, respectively, located one below the other at a distance A = 15 m

Then, in the upper horizontal shafts 4 ′, 4 ″, 4 ″ ′, ... 4 ^{n of the} heating wells 2 ′, 2 ″, 2 ″ ′, ... 2 ⁿ , hydraulic fracturing is performed with formation of longitudinal cracks 6 ′, 6 ″, 6 '', ... 6 ⁿ and their subsequent fastening a conductive material.

For longitudinal fractures 6 ', 6 ", 6'', ... 6 ⁿ drilled horizontal stems 4', 4", 4 "', ... 4 ⁿ respective heater wells 2', 2", 2 "', ... 2 ⁿ in the direction of the maximum stress σ _max in reservoir 1.

Hydraulic fracturing is carried out by any known method, for example, as described in patent RU No. 2485306, IPC E21B 43/26, publ. 06/20/2013, bull. Number 17.

As conductive material, injected into the longitudinal cracks 6 of the horizontal shafts 4 and 5 of the corresponding wells 2 and 3 for the purpose of fixing them, for example, artificial graphite mixed with aluminum powder in a ratio of 3: 1 by weight is used. Artificial graphite has the following physicochemical properties:

- bulk density, g / cm, not less than 0.05;

- carbon,%, not less than 99.0;

- humidity,%, not more than 1.0;

- sulfur,%, not more than 0.05;

- ash content,%, not more than 1.0.

Aluminum powder is produced in accordance with GOST 5494-95.

For example, to attach one horizontal trunk 200 m long, it is necessary to use 12 tons of granular graphite and 4 tons of aluminum powder.

Mixing artificial graphite weighing 12 tons and aluminum powder weighing 4 tons is carried out at the wellhead in the hopper of the mixing unit (not shown in Figs. 1 and 2).

Then, perpendicular to the initial section of the upper horizontal shafts 4 ′, 4 ″, 4 ″ ′, ... 4 ⁿ (see FIGS. 1 and 2) of the heating wells 2 ′, 2 ″, 2 ″ ′, ... 2 ⁿ drill the first production well 7 s horizontal well 7 ′, and perpendicular to the end portion of the upper horizontal shafts 4 ′, 4 ″, 4 ″ ’, ... 4 ⁿ heating wells 2 ′, 2 ″, 2 ″’, ... 2 ⁿ drill the second production well 8 with horizontal well 8 ′ .

Horizontal shafts 7 ′ and 8 ′ of production wells 7 and 8, respectively, were drilled within the hydraulic fractures 6 ′, 6 ″, 6 ″ ′, ... 6 ⁿ . The fixed hydraulic fractures 6 ′, 6 ″, 6 ″ ′, ... 6 ⁿ can have a height of up to 7 m.

Between production wells 7 and 8, additional production wells 9 ′ and 9 ″ are drilled perpendicular to the horizontal shafts of heating pairs 2 ′, 2 ″, 2 ″ ″, ... 2 ⁿ and production 3 ′, 3 ″, 3 ″ ’, ... 3 ⁿ wells with parallel horizontal trunks 4 ′, 4 ″, 4 ″ ′, ... 4 ⁿ and 5 ′, 5 ″, 5 ″ ′, ... 5 ^n, respectively.

The horizontal trunks of the additional production wells 9 ′ and 9 ″ are placed in the middle between the upper 4 ′, 4 ″, 4 ″ ″, ... 4 ⁿ and the lower 5 ′, 5 ″, 5 ″ ’, ... 5 ⁿ horizontal trunks of the heating 2 ′, 2 ″ , 2 ″ ′, ... 2 ⁿ and production 3 ′, 3 ″, 3 ″ ′, ... 3 ⁿ wells, respectively.

For example, with a length L = 150 m of horizontal shafts 4 ′, 4 ″, 4 ″ ″, ... 4 ^{n of} heating wells 2 ′, 2 ″, 2 ″ ’, ... 2 ⁿ two additional production wells 9 and 9 are drilled at equidistant distances ″, I.e. at a distance of b = 50 m from the first 7 and second 8 technological wells, respectively, as well as at a distance of b = 50 m between additional production wells 9 ′ and 9 ″ with horizontal shafts located in the middle, i.e. at a distance c = 15/2 = 7.5 m between the upper 4 ′, 4 ″, 4 ″ ′, ... 4 ⁿ and the lower 5 ′, 5 ″, 5 ″ ′, ... 5 ⁿ horizontal trunks of the heating 2 ′, 2 ″ , 2 ″ ′, ... 2 ⁿ and production 3 ′, 3 ″, 3 ″ ′, ... 3 ⁿ wells, respectively.

In the horizontal wellbore 7 ′ of the first production well 7, an electrode 10 is installed - the cathode “+”.

In the horizontal shaft 8 ′ of the second production well 8, an electrode 11 is installed - an anode “-”.

Electrodes 10 and 11 intersect hydraulic fractures 6 ′, 6 ″, 6 ″ ′, ... 6 ⁿ in the upper horizontal shafts 4 ′, 4 ″, 4 ″ ’, ... 4 ⁿ heating wells 2 ′, 2 ″, 2 ″’, ... 2 ⁿ and interact with the conductive material filling the hydraulic fractures 6 ′, 6 ″, 6 ″ ′, ... 6 ⁿ .

As electrodes lowered into the well, a column of sucker rods with a diameter of 22 mm is used. At the wellhead, electrodes 10 and 11 are connected to an electrical substation 12 of any well-known manufacturer.

They equip the lower horizontal shafts 5 ′, 5 ″, 5 ″ ″, ... 5 ⁿ production wells 3 ′, 3 ″, 3 ″ ’, ... 3 ⁿ and horizontal shafts of additional production wells 9 ′, 9 ″ with electric centrifugal pumps.

The development of deposit 1 is started. The electric substation 12 is launched into operation, which supplies electric current to the electrodes 10 and 11, through which the electric current passes through cracks 6 ′, 6 ″, 6 ″ ′, ... 6 ⁿ fixed by the conductive material along the entire length (L = 150 m) of horizontal shafts 4 ′, 4 ″, 4 ″ ″, ... 4 ^{n of} heating wells 2 ′, 2 ″, 2 ″ ’, ... 2 ⁿ , while cracks 6 ″, 6 ″ ″, 6 fixed by conductive material ⁿ work as heating elements.

The heat generated from cracks 6 ′, 6 ″, 6 ″ ′, ... 6 ⁿ is transferred to the surrounding rock (deposit 1), causing them to heat up. As a result, high-viscosity oil and bitumen located in reservoir 1 are heated to a temperature sufficient for its flow in reservoir 1 under the influence of gravitational forces. The pumps placed in the lower horizontal shafts 5 ′, 5 ″, 5 ″ ″, ... 5 ⁿ production wells 3 ′, 3 ″, 3 ″ ’, ... 3 ⁿ , as well as in horizontal shafts of the additional production wells 9 ′, are put into operation, 9".

The efficiency of heating a highly viscous oil and bitumen deposit increases due to the fact that heating covers the entire area of reservoir 1. This occurs along the entire length (L = 150 m) of horizontal shafts 4 ′, 4 ″, 4 ″ ″, ... 4 ⁿ heating wells 2 ′, 2 ″, 2 ″ ′, ... 2 ⁿ , as well as over the entire width of deposit 1 at a distance of a = 50 m between parallel horizontal shafts 4 ′, 4 ″, 4 ″ ’, ... 4 ^{n of} heating wells 2 ′, 2 ″, 2 '', ... 2 ^n, wherein a heating point is excluded deposits electric field generated between the electrodes with the electrical substation after uyuschey pumping limited amount of oil and heated bitumen reservoir to another part, so simplifies the technological process of the method.

As a result of the process in the upper horizontal shafts 4 ', 4 ", 4"', ... 4 ⁿ heater wells 2 ', 2 ", 2"', ... 2 ⁿ are formed respective longitudinal crack 6 ', 6 ", 6"', ... 6 ⁿ up to 7 m high, which allows to increase the reservoir coverage by heat exposure up to 15 m, while the reservoir is uniformly heated along the entire length of the horizontal trunk, the oil recovery of the highly viscous oil and bitumen deposits increases.

Heated high-viscosity oil and bitumen under the influence of gravity flow down into the lower horizontal shafts 5 ′, 5 ″, 5 ″ ’, ... 5 ⁿ producing wells 3 ′, 3 ″, 3 ″’, ... 3 ⁿ and into horizontal shafts of additional producing wells 9 ′, 9 ″. From where submersible electric centrifugal pumps (shown in Fig. 2 conventionally) are selected on the day surface.

The re-injection of heated oil and bitumen into the reservoir is eliminated, where they manage to partially cool, and the presence of two additional horizontal production wells 9 ′, 9 ″ (see Figs. 1 and 2), drilled in parallel at an equidistant distance from each other and between the upper 4 ′, 4 ″, 4 ″ ′, ... 4 ⁿ and lower 5 ′, 5 ″, 5 ″ ′, ... 5 ^{n with} horizontal shafts of heating 2 ′, 2 ″, 2 ″ ′, ... 2 ⁿ , and mining 3 ′, 3 ″, 3 ″ ′, ... 3 ⁿ wells, respectively, allows to increase the volumes of extraction (flow rate) of heated oil and bitumen from reservoir 1.

When implementing the proposed method, the use of submersible electric centrifugal pumps of a special design for reversing products in the well is excluded, therefore, due to the exclusion of reversal, it is not necessary to place the pumps in horizontal conditions, and therefore the working conditions of submersible electric centrifugal pumps are improved and the reliability of the method is improved.

The proposed development method allows to increase the efficiency of heating deposits of high viscosity oil and bitumen by heating, to simplify the process of implementing the method, to increase the coverage of the deposit by heating, to increase the volumes of selection of heated oil and bitumen, and the reliability of the method.

Claims (1)

A method for developing a deposit of high-viscosity oil and bitumen, including drilling a deposit with two technological wells and a producing well with horizontal shafts, installing electrodes in horizontal shafts of technological wells, connecting electrodes to an electrical substation at the wellhead, lowering an electric centrifugal pump into a horizontal well of a producing well, heating the deposit with an electric electric current using electrodes installed in horizontal trunks of technological wells, selection of heated oil and itum from a deposit by an electric centrifugal pump from a horizontal wellbore of a producing well, characterized in that at least one producing and one heating well with horizontal shafts located parallel and under each other at a distance of 15 m is drilled, then hydraulic fracturing is performed in the upper horizontal well of the heating well formation with the formation of a longitudinal crack with its subsequent fastening with conductive material, then perpendicular to the initial section of horizontal c the borehole of the heating well is drilled the first production well with a horizontal wellbore, and perpendicularly to the end portion of the horizontal well of the heating well is drilled the second technological well with a horizontal wellbore, and the horizontal wells of the technological wells are placed within hydraulic fractures, then between the technological wells are parallel to their vertical shafts and perpendicular horizontal trunks pairs of heating and producing wells are drilling two additional whole production wells, horizontal shafts of additional production wells are placed parallel and between the upper and lower horizontal shafts of the heating and production wells, pump rods are used as electrodes lowered into the well, the lower horizontal trunk of the production well and horizontal shafts of the additional production wells are equipped with electric centrifugal pumps , carry out the heating of the deposits using the upper horizontal shaft of the heating well, and the selection is heated x oil and bitumen is carried out using electrical submersible pump via the lower horizontal wellbore of the production well and the horizontal production wells additional trunks.

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