RU2733563C2 - Method of producing bituminous oil from a horizontal well - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention relates to a method of producing bituminous oil from a horizontal well. Method of producing bituminous oil from a horizontal well includes installing a casing string, annular space cementing above a horizontal portion, in which there is a perforation in the end portion and at the beginning of the horizontal portion, lowering the tubing string with the pump and drive, installing the packer between the perforated parts, lowering the production string, pumping of steam into the formation through the service column into the initial part and extraction of liquid by the pump with the drive from the formation through the end part of the horizontal section. Pump inlet is located in end part of horizontal section after lowering of tubing string. Technical string is located inside the tubing string and is communicated via radial channels for steam injection with the initial part of the horizontal section.

EFFECT: technical result is reduction of pressure and heat losses at pump inlet.

1 cl, 2 dwg, 1 ex

Description

The invention relates to the oil industry, to thermal methods for extracting high-viscosity oil or bitumen from a single horizontal well.

There is a known method for the development of an oil field (Patent RU No. 2350747, IPC Е21В 43/24, publ. 20.07.2012 in Bull. No. 20), including drilling a horizontal storey well with the placement of two horizontal shafts in one vertical plane and displacing viscous oil or bitumen by coolant injection, while specifying the distribution of productive strata over the area of the deposit, horizontal wells are placed in the interval of the most permeable layer at least 6 m above the bottom of the formation of viscous oil or bitumen or water-bitumen contact and with the distance between the bottom of these shafts not exceeding 5 m , sidetracking windows of horizontal boreholes are located in the oil-saturated reservoir at a distance of 8-10 m from each other, horizontal boreholes are drilled along an ascending trajectory and placed towards the dome of the reservoir, and the bottom of each borehole is located above the sidetracking window, two tubing pipes are lowered with centralizers, the coolant is pumped cyclically or constantly through the upper horizontal wellbore while maintaining pressure at its bottom close to hydrostatic, while the viscous oil or bitumen is withdrawn continuously through the lower horizontal wellbore.

The disadvantages of this method are the high cost and complexity of drilling a horizontal storey well with the placement of two horizontal boreholes in one vertical plane, the complexity of the installation of the lowered equipment. The need to drill two horizontal wellbores limits the choice of the development area in terms of the thickness of the productive formation.

A known method of thermal displacement of oil from a horizontal well (RF Patent No. 2067168, IPC Е21В 43/24, publ. 09/27/1996), including the production of high-viscosity oil by the method of cyclic pumping of a coolant into the end of the horizontal wellbore and withdrawal of liquid from the steam injection zone separated by the packer the nearest site. The method is implemented as follows: perforation is performed along the annular generatrix at the beginning and at the end of the horizontal part of the production casing section, tubing pipes (tubing) equipped with a packer device that disconnect the horizontal wellbore between these two groups of perforation are lowered to the perforation interval closest to the bottom ... The coolant is pumped along the tubing into the formation through the remote perforation zone, and the fluid is withdrawn from the perforated zone near the wellhead. The liquid is transported to the surface along the annular annular space of the well.

The method has the following disadvantages:

- the proposed method provides only a gusher method for lifting liquid to the surface along the annular space, which gives an unstable and low fluid withdrawal;

- no preheating of the entire zone is provided.

The closest in terms of the totality of features is a method of high-viscosity oil production by the method of simultaneous steam injection and liquid withdrawal from a single horizontal well (Patent RU No. 2456441, IPC Е21В 43/24, published on July 20, 2012 in Bull. No. 20), including the installation of a casing, cementing the annular space above the horizontal section, in which perforation was performed in the end part and at the beginning of the horizontal section, running the tubing string (tubing) with a packer installed between the perforated sections, injecting steam into the formation and withdrawing fluid from the formation, and before running the string The tubing string is lowered into the well to the horizontal section, into which the tubing string is lowered with a pump located in the lower part of the technical string and allowing steam to be injected into the formation through it, and steam is first pumped into the formation along the space between the technical string and the tubing string, as well as along the tubing string through the pump, while the total volume The volume of injected steam is 5-7 t / m of the total length of the perforated sections, after which the injection is continued in the space between the technical string and the tubing string, and the fluid is withdrawn by a pump along the tubing string.

The disadvantages of this method are a large decrease in pressure when supplying formation products through the liner to the pump inlet, which leads to a decrease in pump efficiency, large heat losses when pumping steam through a technical column interacting with the annular space and casing, and through it with the opened wellbore breed.

The technical objectives of the proposed invention are to reduce the pressure loss at the pump inlet and heat due to respectively placing the pump in the immediate vicinity of the production area of the horizontal well and pumping steam through the technical pipe string located inside the tubing string.

Technical problems are solved by the method of bituminous oil production from a horizontal well, including the installation of a casing string, cementing of the annular space above the horizontal section, in which perforation is performed in the end part and at the beginning of the horizontal section, running the tubing string - tubing with a pump and a drive, installation the packer between the perforated sections, running the service string, injecting steam into the formation through the service string into the initial section and withdrawing fluid from the formation by a pump driven from the formation through the end of the horizontal wellbore.

The novelty is that the pump inlet is located at the end of the horizontal wellbore after running the tubing string, the technical string is positioned inside the tubing string and radial channels communicate with the initial part of the horizontal wellbore for steam injection.

It is also new that a steam turbine is installed in the form of a pump drive, and the technical string is connected to the drive inlet, the output of which is communicated by radial channels for steam injection with the initial part of the horizontal wellbore.

FIG. 1 shows a diagram of the implementation of the method.

FIG. 2 shows a section A-A, see Fig. 1.

The method is implemented as follows

The method of producing bituminous oil from a horizontal well includes the installation of a casing string 1 (Fig. 1), cementing the annular space (not shown) above the horizontal section 2, in which perforation is made in the end part 3 by holes 4 and the initial part 5 by holes 6 of the horizontal section 2, running the tubing string - tubing 7 with pump 8 and drive 9, installing packer 10 between perforated parts 3 and 5, running service string 11, injecting steam into the reservoir through service string 11 into the initial part 5 and withdrawing fluid by pump 8 with a drive 9 from reservoir 12 through the end part 3 of the horizontal section 2. The inlet 13 of the pump 8 is located in the end part 3 of the horizontal section 2 after running the tubing string 7. The technical string 11 is placed inside the tubing string 7 and radial channels 14 (Fig. 2) are communicated for injection pair with the initial part 5 of the horizontal section 2 (Fig. 1). A steam turbine can be installed in the form of a drive 9 of a pump 8, and the technical column 11 is connected to the inlet 15 of the drive 9, the outlet 16 of which by radial channels 14 (Fig. 2) communicates for steam injection with the initial part 5 (Fig. 1) of the horizontal section 2. Holes 4 and 6 can be made using a perforator (not shown) or when running the liner with finished holes 4 and 6 in the corresponding parts 3 and 5. Technical and / or technological elements that do not affect the performance of the method are not shown or are shown in the figures conventionally.

An example of a specific implementation

A well was built from the surface with a siege column 1 (Fig. 1) and a horizontal section 2, located in the productive stratum 12. The reservoir and thermal properties of the exposed stratum 12 were clarified. The development section of the productive stratum 12, on which the claimed technology was carried out, has geometric dimensions of 400 × 100 × 15 m.The average thickness of formation 12 is 15 m. Cementing of the casing string 1 was carried out to the horizontal section 2, in which perforation was made in the end part 3 with holes 4 and in the initial part 5 holes 6 of the horizontal section 2, for which a liner was run with ready holes 4 and 6 in respective parts 3 and 5. We ran tubing string 7 with packer 10, pump 8 ("PCM Vulcain ™") and drive 9. Packer 10 was installed between perforated parts 3 and 5, and inlet 13 of pump 8 was located in the end part 3 behind the packer 10. The technical string 11 was lowered to communicate with the radial channels 14 (Fig. 2) communicated with the space of the initial part 5 (Fig. 1 ) of the horizontal section 2 outside the tubing string 7. A steam turbine was used as a drive 9, through which the technical string 11 communicates with the radial channels 14 (Fig. 2). The drive 9 (Fig. 1) is in communication with the column 11 with its inlet 15, and with the outlet 16 with radial channels 14 (Fig. 2).

For pumping into formation 12 (Fig. 1) through the corresponding holes 4 and 6 along the tubing string 7, 1000 tons of steam were pumped into the end part 3 through the screw pump 8, 1300 tons of steam were pumped in the space between the casing string 1 and the tubing string. couple. After receiving the heated zone 17 with a temperature of at least 90 ° C, injection through the tubing string 7 was stopped. We started the pump 8 using the drive 9 and began to take the production of the formation 12 of the end part 3 of the horizontal section 2. For this, steam is injected along the technical string 11, which passes through the drive 9, the radial holes 14 (Fig. 2) and then outside the tubing string 7 ( Fig. 1) through the initial part 5 with holes into the formation 12, maintaining the temperature in the heated zone 17.

For the comparison base, the option of steam injection was adopted using a single horizontal well with a horizontal wellbore of 419 m, operating according to the technology of the closest analogue. The results showed that the efficiency of the proposed method for extracting bituminous oil due to the reduction of energy and heat losses is higher: the maximum achievable oil recovery factor is 5% higher, the maximum oil production rate was 7 tons / day versus 1.5 tons / day.

The proposed method for the extraction of bituminous oil from a horizontal well allows to reduce the pressure loss at the pump inlet and heat due to, respectively, placing the pump in the immediate vicinity of the production area of the horizontal well and pumping steam through a technical pipe string located inside the tubing string.

Claims (2)

1. A method for producing bituminous oil from a horizontal well, including the installation of a casing string, cementing the annular space above the horizontal section, in which perforation is performed in the end part and at the beginning of the horizontal section, lowering the tubing string - tubing with a pump and drive, installing a packer between the perforated parts, lowering the technical string, injecting steam into the reservoir through the technical string into the initial part and withdrawing fluid from the reservoir by a pump driven from the reservoir through the end part of the horizontal section, characterized in that the pump inlet is located at the end of the horizontal section after running the tubing string, technical the string is placed inside the tubing string and the radial channels communicate for steam injection with the initial part of the horizontal section. 2. The method for producing bituminous oil from a horizontal well according to claim 1, characterized in that a steam turbine is installed as a pump drive, and the technical string is connected to the drive inlet, the output of which is communicated by radial channels for steam injection with the initial part of the horizontal section.

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