RU2375560C1 - Natural bitumen production method - Google Patents

Abstract

FIELD: oil-and-gas production.

SUBSTANCE: invention related to oil-and-gas production, particularly to natural bitumen or crude viscous oil production. Essence of invention: to locate boring string inside casing string, column or columns for heat transfer agent supply, and hydro-monitoring nozzles for heat transfer injection. Generate heat transfer agent circulation. Bore a hole in a natural bitumen reservoir and supply it with the heat transfer agent. And dilute natural bitumen with water crushing a rock at the same time, and lift up created bituminous with heat transfer agent to the surface. Methods provides natural bitumen production from different reservoir types.

EFFECT: increase in bitumen production efficiency because of intensification of hydraulic and thermal treatment with a heat transfer agent also with decrease of power consumption.

7 cl, 7 dwg

Description

The inventive method relates to the oil industry, namely the extraction of natural bitumen or heavy viscous oil.

A known method for the extraction of natural bitumen is a steam-thermal method based on gravity drainage using steam [1]. To implement this method, two horizontal wells with parallel shafts are drilled. Steam is pumped into the upper barrel, and heated bitumen is mined from the lower barrel.

In the mining process, the following principle is used. The injected steam tends to the upper part of the formation, heats the bitumen, which, under the influence of its own weight, falls to the lower trunk. Bitumen and hot steam condensate are taken from the lower horizontal well.

This mining method has the following disadvantages.

As domestic experience has shown, the distance between the upper and lower trunks should optimally be no more than 5 meters. However, even at this distance, considerable time and energy are spent on heating the bitumen.

Productive strata with bitumen, as a rule, have a heterogeneous structure: intercalation of bitumen with water-saturated layers represented by weakly cemented sandstones. However, the known method of mining bitumen is not adjustable depending on the type of rock.

In addition, the known method is not economical, since a lot of coolant goes beyond the boundaries of the operating area.

The closest technical solution adopted for the prototype is a method of extracting natural bitumen using underground surface technology, including displacing bitumen from the formation with a coolant through a well drilled from the surface [2]. For uniform distribution of steam over the formation, special underground steam distribution wells are drilled to the bottom faces of surface injection wells.

Drilling a large number of wells for drilling bitumen in this way accelerates the heating of the reservoir, but it is economically justified only at those facilities where horizontal wells already exist. If there are loose sands in the fields, the wells are blocked by them, after which they are difficult to recover.

When using the above-described method for Mordovo- Karmalskoye field Tatarstan annual vapor gas flow of 4.4 million m ^3, the specific consumption of which was 3.4 thousand ^m3 / t bitumen specific steam consumption of about 3.5 ton / ton. The method turned out to be uneconomical, since heating is carried out over a large space, and bitumen is not heated to a fluid state.

The objective of the present invention is to increase the efficiency of production of bitumen from the reservoir due to the intensification of the hydraulic and thermal effects of heat carrier on it while reducing energy costs.

The problem is solved due to the fact that in the method of extracting natural bitumen by displacing it from the passable rocks by the coolant in the process of drilling a well using a drill pipe string and a coolant supply column, the extraction is carried out by washing the natural bitumen coolant with the simultaneous destruction of rocks.

The method of extraction of bitumen by the wash method differs in its technology, depending on the properties of the rock in which natural bitumen (PB) is deposited.

The inventive method is illustrated in Fig.1-7.

When mining from a reservoir composed of loose uncemented PB, the layout shown in Fig. 1 is proposed. It consists of a casing string 1, within which a drill pipe string 2 and a coolant supply string 3 are placed. When the drill pipe is located inside the string of pipes for the coolant at the end of the latter is installed hydromonitor nozzle 4.

The method is implemented as follows. First, a circular coolant circulation is provided in the well. Then the layout goes down to the bottom of the borehole and the drill string 2 and the drill string 3 rotate simultaneously. Hot water or brine is used as the coolant and a circular circulation is created. Due to the flow of fluid flowing out of the nozzle 4, the loose non-cemented PB at the bottom is destroyed and transported to the surface together with the coolant.

When the PB is located close to the surface at a shallow depth, there is no need for a constant supply of coolant, as a result of which the column for supplying the coolant is lowered to the bottom as the technological need.

In this case, the proposed arrangement shown in figure 2, including the casing 1, the drill pipe string 2 and the coolant string 5, located not inside, but in the annular space between the drill and casing.

When mining from a reservoir composed of loose, with the inclusion of cemented individual particles of PB, the layout shown in figure 3 is applied. It consists of a casing string 1, a drill pipe string 2 and a transport string 6. At the lower end of the drill string there is an ejector device consisting of a casing 7 with an annular cavity 8. The casing has outer 9 and inner 10 radial holes, as well as axial holes 11 and 12 made in the form of nozzles. The hole 12 is used to wash out the particles of the drilled rock, and the hole 11 is designed to create an ejector effect in order to feed the pulp into the transport column 6.

To destroy the bottom of the bottom end of the housing 7 is equipped with teeth 13. Between the drill string 2 and the transport string 6 is installed packing sleeve 14.

The method is implemented as follows. First, a circular coolant circulation is provided in the well. Then the layout goes down to the bottom and the rotation of the drill string begins. The coolant from the surface through the annular space formed by the columns 2 and 6, through the holes 10 enters the annular cavity 8 and then into the holes (nozzles) 11 and 12. The hole 12 together with the teeth 13 provides erosion and drilling of bitumen pulp, which through the openings 9 enters in the lower part of the transport column 6 and is carried away by the flow of coolant to the surface under the influence of a jet flowing from the hole 11.

Figure 4 presents the layout for the extraction of PB from the reservoir, composed of coarse sand and pebbles. The device consists of a casing string 1, inside of which a drill pipe string 2 and a transport string 15 are located. Between the pillars 2 and 15, a ring 16 is installed in the lower part with several hydraulic monitor nozzles 4 located at the periphery. A bell 17 is placed in the lower part of the drill string 2, end which is made in the form of a mill 13. Inside the column 15, the fittings 18 are mounted.

The method is implemented as follows. The layout is lowered into the well, a circular circulation of the coolant is provided and the rotation of the drill string begins. PB, being destroyed under the influence of the hydro-monitor effect and teeth 13 on the bell 17, is directed inside the transport column 15. The bell helps to capture the destroyed PB. The coolant goes to the bottom, forming a large-sized PB concentrated in the liquid into a uniform pulp, and then rises to the surface through the transport pipe 15. The necessity of using a hydromonitor system with several nozzles is determined by the difficulty of uniformly supplying PB with coarse sand and pebbles to the transport pipe without their accumulation at the inlet and thereby blocking the column for transporting PB to the surface. Thanks to the fittings 18 installed in the inner pipe, large particles are mixed together to create a uniform pulp stream with dispersed particles of coarse sand, pebbles and conglomerates of PB. This arrangement is especially effective when operating horizontal wells.

When extracting bitumen from the reservoir, the skeleton of which is represented by dense permeable rocks, the layout shown in Fig. 5 is used. It includes a casing string 1, through which drill pipe string 2 and string 5, designed to supply coolant. Column 5 can be placed both inside the drill string 2 and in the annular space between the drill and casing.

A hydraulic monitor nozzle 4 is installed at the end of the column 5, and an electric drill 20 is installed at the lower end of the drill string 2, the hollow output shaft of which (not shown) is connected to the pump 21 and the bit 22.

The method is implemented as follows. The layout is lowered into the well and circular circulation of the coolant is provided. Through a cable located inside the drill string, voltage is supplied to the electric drill 20. An electric drill with a bit 22 is included in the work. The rock with PB destroyed by the bit, together with the coolant, enters the hollow shaft of the electric drill and then is pumped to the surface by the drill string 2 with the pump 21.

At small depths of the location of the PB, it is advisable to apply a technological scheme with an external arrangement of the column for supplying the coolant, while during the pumping of the coolant, the column can be lifted from the well. Such a need arises in connection with complications in the well in the form of assembly puffs during tripping operations, etc.

A feature of this arrangement, depicted in Fig.6, is that the column 5 for supplying coolant to the bottom is placed not inside the drill string, but in the annular space between the casing 1 and the drill pipe 2, as well as in the installation of an additional pump 23 and a heater 24 of the moving pulp located in the vertical part of the wellbore.

The principle of operation of this arrangement is similar to that described above and presented in figure 5.

Figure 7 presents a diagram of the production of PB from a large-capacity bituminous formation using multilateral wells with branches from the main cased trunks in the form of numerous open trunks of smaller diameter. In such cases, the main shaft is drilled at the entire thickness of the formation at the same time as the casing is lowered, which, at the end of the drilling, makes it possible, without lifting it, to fasten and then guide the lateral shafts through the windows cut into it, using the main shaft to inflow PB from the entire system branched open trunks.

Formations with PB in most fields have a large capacity. Efficient production is achieved if additional layers in the form of horizontal shafts are drilled over the thickness of the bitumen reservoir. Due to this, a system of intensive inflow of PB from them to the central trunk is created, from which the PB rises to the surface through thermal or pumping methods of operation.

Sources of information taken into account

1. Shandrygin A.N., Nukhaev M.T., Tertychny V.V. Development of heavy oil and natural bitumen deposits by the method of steam gravity drainage. Oil industry, No. 6, 2006, p. 94.

2. Tabakov V.P., Gurov E.I. Thermal mine method for developing oil and bitumen deposits. Oil industry, No. 3, 1993, p. 43 (prototype).

Claims (7)

1. A method of producing natural bitumen, characterized in that a drill string, a column or columns for supplying a coolant are placed inside the casing, and a hydraulic monitor nozzle or hydraulic monitor nozzles for supplying a coolant provide circular circulation of the coolant, a well is drilled through a natural bitumen reservoir with a coolant supply , while natural bitumen is eroded and at the same time the rock is destroyed, and the resulting bitumen pulp is lifted by the flow of coolant to the surface. 2. The method according to claim 1, characterized in that when producing from a reservoir composed of loose non-cemented natural bitumen, a hydraulic monitor nozzle is installed at the end of the coolant supply column, which is placed inside or outside the drill string. 3. The method according to claim 1, characterized in that when producing from a reservoir composed of friable with the inclusion of cemented individual particles of natural bitumen, a drill string is used with an ejector device having a cavity through which the coolant is supplied, and the hydraulic nozzles are central in the ejector device. 4. The method according to claim 1, characterized in that when producing from a formation composed of coarse sand and pebbles and saturated with bitumen, a transport column is placed inside the drill string, and the hydraulic nozzles are placed in their lower part in the annular space. 5. The method according to claim 1, characterized in that when mining bitumen from the formation, the skeleton of which is represented by dense permeable rocks, an electric drill is installed at the end of the drill string, the hollow output shaft of which is connected to the pump and the bit, while the column for supplying a heat carrier with a hydraulic monitor the nozzle at the end is placed inside or outside the drill string. 6. The method according to claim 1 or 5, characterized in that in the vertical part of the barrel an additional pump and heater are installed for the moving pulp. 7. The method according to claim 1, characterized in that additional layers in the form of horizontal shafts are drilled during the power of the bitumen formation.

Images