System and method for achieving thick oil injection and production integration through small oil pipe throwing and fishing electric pump

Abstract

The invention discloses a system for realizing thick oil injection and production integration by throwing and fishing an electric pump through a small oil pipe, which comprises an outer-layer heat injection tubular column and an inner-layer production tubular column, the production tubular column comprises a small oil pipe, an electric submersible pump connector and an inverted electric submersible pump from top to bottom, and the electric submersible pump connector is provided with a second diversion through hole. Ground operation equipment involved in the method is few, the operation efficiency is high, and operation resources and cost are saved; a small oil pipe is selected as an output liquid output channel, fluid soaking and scouring in an annular space of an inner-layer production pipe column and an outer-layer heat injection pipe column are avoided, the heat insulation performance of the heat insulation oil pipe can be protected, the cable insulation performance can be protected, and the failure risk is reduced. The electric submersible pump unit adopts an inverted pump design, a cable penetrates through an upper production packer and then is directly connected with an electric submersible pump motor, the cable collapse risk is reduced, and the operation stability of an electric submersible pump in a highly-deviated well is improved; the small oil pipe is high in throwing and fishing capacity, and throwing and fishing of the electric submersible pump in a highly-deviated well and a horizontal well can be achieved.

Description

Technical Field

[0001] This invention relates to the field of offshore heavy oil thermal recovery technology, and in particular to an integrated system and method for heavy oil injection and recovery using a small tubing-launched electric pump. Background Technology

[0002] Offshore oilfields are rich in heavy oil resources, and steam injection is an important means to improve oil recovery. Currently, integrated steam injection and production are mainly achieved through two technological approaches. The first approach, for example, patent application number 202210768088.6, discloses a method for integrated injection and production using an electric submersible pump. After heating, well shut-in, and blowout, a composite cable is used to deploy the electric submersible pump into the heating tubing for production. After production, the electric submersible pump is retrieved for a new round of heating. This process can save one operation of moving the tubing and improve the efficiency of steam injection; however, it requires a dedicated Christmas tree, and the continuous tubing requires numerous ground-based supporting equipment, occupying a large area, which limits its application on offshore platforms. The produced fluid production channel is an insulated tubing, and long-term scouring and soaking can easily lead to a decline in insulation performance. Using a positive-position pump, some small flat cables in the unit need to cross over a larger centrifugal pump to connect to the motor, which can easily lead to the crushing of small flat cables in highly deviated wells. The deployment and retrieval capacity of the composite cable is greatly affected by the well inclination, and its adaptability in highly deviated wells is poor. The second type, such as the patent application number 202010095172.7, discloses an integrated injection and production device for offshore heavy oil steam injection. A Y-string is installed, the tubing is insulated, and the electric submersible pump is a high-temperature electric submersible pump. During the well completion stage, the string and the electric submersible pump are directly installed into the wellbore. The string is designed with an injection / production switching valve to switch the injection / production channel. This process can achieve integrated injection and production without moving the string. However, it has extremely high requirements for the high temperature resistance of the electric submersible pump. At present, the high-temperature electric submersible pump is still in the research and development and improvement stage and has not yet entered large-scale application. Summary of the Invention

[0003] This invention provides a system and method for integrating heavy oil injection and production by deploying an electric submersible pump using a small tubing. A heat-insulated tubing is run into the casing for heating. After well shut-in and blowout, an inverted electric submersible pump is deployed using a small tubing to achieve integrated injection and production. The operation can be completed using a platform workover rig, requiring no additional equipment, thus saving operating costs. It also reduces the risk of damage to the small flat cable of the electric submersible pump and has good adaptability in highly deviated and horizontal wells.

[0004] To achieve the above objectives, this application provides the following technical solution:

[0005] A heavy oil injection and production integrated system that uses a small tubing-based electric pump for deployment includes:

[0006] The heat injection string is located inside the casing. The heat injection string includes, from top to bottom, a first insulating oil pipe, a perforated pipe, and a second insulating oil pipe. A high-temperature packer is provided between the first insulating oil pipe and the casing. The high-temperature packer is equipped with a vent valve. The perforated pipe is equipped with a first guiding hole, which is used to connect the inner cavity of the perforated pipe with the outer heat injection string and the casing annulus. A deep well safety valve is provided on the second insulating oil pipe. The second insulating oil pipe below the deep well safety valve extends into the sand control string. The diameter of the first insulating oil pipe is larger than the diameter of the second insulating oil pipe.

[0007] A production string, adapted to be inserted into the first insulated tubing, comprises a small tubing, an ESP connector, and an inverted ESP from top to bottom. An upper production packer is provided between the small tubing and the first insulated tubing, and a lower production packer is provided between the inverted ESP and the first insulated tubing. The ESP connector is provided with a second flow-through hole, which is used to connect the inner cavity of the small tubing with the annulus of the outer heat injection string and the inner production string.

[0008] When injecting hot fluid, the hot fluid passes through the first insulated oil pipe, the perforated pipe, the second insulated oil pipe, the deep well safety valve, and the second insulated oil pipe to the formation;

[0009] During gas injection, the gas passes through the oil production tree valve, the first insulated oil pipe and casing annulus, the vent valve, the first insulated oil pipe and casing annulus, the perforated pipe, the second insulated oil pipe, the deep well safety valve, and the second insulated oil pipe to the formation.

[0010] When producing through the inner layer production string, the formation produced fluid passes through the formation, the second insulated tubing, the deep well safety valve, the second insulated tubing, the perforated tubing, the inverted electric submersible pump, the inverted electric submersible pump and the first insulated tubing annulus, the electric submersible pump connector and is then produced through the small tubing.

[0011] Optionally, the electric submersible pump connector includes an upper connecting pipe and a lower connecting pipe. The upper connecting pipe has an upper interface for connecting a small oil pipe, and the side wall of the upper connecting pipe has a second guide hole. The lower connecting pipe has a lower interface for connecting an inverted electric submersible pump, and a partition plate is provided between the upper connecting pipe and the lower connecting pipe.

[0012] Optionally, the inverted electric submersible pump includes, from top to bottom, a motor, a protector, a centrifugal pump outlet, a centrifugal pump, a centrifugal pump inlet, and a guide pipe. The motor is connected to the lower interface of the lower connecting pipe. The centrifugal pump outlet is used to connect the centrifugal pump with the annulus between the outer heat injection tube column and the inner production tube column. The centrifugal pump inlet is used to connect the inner cavity of the guide pipe and the centrifugal pump. A gas separator is provided on the guide pipe.

[0013] The formation produced fluid passes through the formation, the second insulated tubing, the deep well safety valve, the second insulated tubing, the perforated pipe, the guide pipe, the centrifugal pump inlet, the centrifugal pump, the centrifugal pump outlet, the inverted electric submersible pump and the first insulated tubing annulus, the electric submersible pump connector and is produced through the small tubing.

[0014] Optionally, the lower production packer is located outside the guide pipe, below the gas separator and above the perforated pipe.

[0015] Optionally, both the upper and lower production packers employ hydraulic setting and lifting of the tubing for unsealing. The upper and lower production packers share a single hydraulic control line, and are connected to ground control equipment via this hydraulic control line.

[0016] Optionally, the high-temperature packer is hydraulically set and unsealed by lifting the tubing string. The high-temperature packer is connected to the ground control equipment via a high-temperature packer hydraulic control line. The venting valve is connected to the ground control equipment via a venting valve hydraulic control line. The deep well safety valve is connected to the ground control equipment via a deep well safety valve hydraulic control line.

[0017] Optionally, the first insulated oil pipe is suspended inside the casing by a large oil pipe hanger seal, and the small oil pipe is suspended at the four-way position of the wellhead by a small oil pipe hanger seal.

[0018] Optionally, the high-temperature packer hydraulic control line, the deep well safety valve hydraulic control line, and the vent valve hydraulic control line are fixed to the outer wall of the first insulated tubing by a pipeline protector, pass through the large tubing hanger, and then pass through the Christmas tree as a whole. The production packer hydraulic control line and the cable of the inverted electric submersible pump are fixed to the outer wall of the small tubing by a pipeline protector, pass through the small tubing hanger, and then pass through the Christmas tree as a whole.

[0019] A method for implementing an integrated heavy oil injection and production system via a small tubing-launched electric pump, comprising:

[0020] S1: Open the deep well safety valve and venting valve, set the high-temperature packer, and inject hot fluid into the well using the hot injection tubing string. Inject gas using the hot injection tubing string and casing annulus. When injecting hot fluid, the hot fluid passes through the first insulated tubing, perforated tubing, second insulated tubing, deep well safety valve, and second insulated tubing to the formation. When injecting gas, the gas passes through the production tree valve, first insulated tubing and casing annulus, venting valve, first insulated tubing and casing annulus, perforated tubing, second insulated tubing, deep well safety valve, and second insulated tubing to the formation. After the hot injection is completed, the process sequentially enters the well shut-in and blowout stages. During the blowout stage, the formation fluid flows through the hot injection tubing string to the wellhead.

[0021] S2: After the blowout is completed, the inverted pump is inserted into the first insulated tubing through the small tubing, the upper and lower production packers are set, the pump is started and production is carried out, the produced fluid is lifted to the wellhead, the formation produced fluid passes through the formation, the second insulated tubing, the deep well safety valve, the second insulated tubing, the perforated tubing, the guide pipe, the centrifugal pump inlet, the centrifugal pump, the centrifugal pump outlet, the inverted electric submersible pump and the first insulated tubing annulus, the electric submersible pump connector and is produced through the small tubing;

[0022] S3: When the output of the electric submersible pump decreases to the economic output, stop the pump, release the upper and lower production packers, and remove the inverted pump unit through the small oil pipe.

[0023] S4: Repeat step S1 again.

[0024] Optionally, when putting in and taking out the inverted pump unit, the moving tubing operation can be completed by a workover rig via a small tubing.

[0025] In summary, the technical effects and advantages of this invention are as follows:

[0026] 1) The steam injection-production process can be converted through a single-stage tubing operation, which involves fewer ground equipment, has high efficiency, and saves resources and costs.

[0027] 2) Selecting small oil pipes as the production fluid outlet channels avoids the fluid from being soaked and scourted in the annular space between the inner production tubing and the outer heat injection tubing. This can protect the heat insulation performance of the heat-insulating oil pipes and the insulation performance of the cables, reducing the risk of failure.

[0028] 3) The electric submersible pump unit adopts an inverted pump design. After the cable passes through the upper production packer, it is directly connected to the electric submersible pump motor, which reduces the risk of cable crushing and improves the operational stability of the electric submersible pump in highly deviated wells.

[0029] 4) By optimizing the flow path of the produced fluid, the gas in the produced fluid can be discharged in time, avoiding the accumulation of gas at the location of the electric submersible pump, which may lead to unstable production or gas lock.

[0030] 5) It has strong small tubing deployment and retrieval capabilities, enabling electric submersible pump deployment and retrieval in highly deviated and horizontal wells. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1This is a schematic diagram of the structure of a heavy oil injection and production integrated system that uses a small tubing to launch an electric pump in one embodiment of the present invention.

[0033] Figure 2 This is a schematic diagram of the structure of an electric submersible pump connector in one embodiment of the present invention;

[0034] Figure 3 This is the flow path of the hot fluid during heat injection through the outer heat injection tube column in one embodiment of the present invention;

[0035] Figure 4 This is the flow path of nitrogen injection through the outer heat injection pipe column-casing annulus in one embodiment of the present invention;

[0036] Figure 5 This is the flow path of the formation fluid produced during production through the inner layer production tubing in one embodiment of the present invention.

[0037] The components include: 1. Casing; 2. Main tubing hanger; 3. First insulated tubing; 4. Vent valve hydraulic control line; 5. High-temperature packer hydraulic control line; 6. Vent valve; 7. High-temperature packer; 8. Perforated tubing; 9. Second insulated tubing; 10. Deep well safety valve; 11. Sand control string; 12. Small tubing hanger; 13. Small tubing; 14. Cable; 15. Upper production packer; 16. ESP connector; 16-1. Upper connecting pipe; 16-2. Second guide hole; 16-3. Lower connecting pipe; 17. Motor; 18. Protector; 19. Production packer hydraulic control line; 20. ESP outlet; 21. Centrifugal pump; 22. Centrifugal pump inlet; 23. Guide pipe; 24. Gas separator; 25. Lower production packer; 26. Deep well safety valve hydraulic control line. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0040] This embodiment proposes an integrated heavy oil injection and production system that uses a small tubing-based electric pump for deployment, such as... Figures 1-5As shown, the system includes a heat injection tube column and a production tube column. The heat injection tube column is located inside the casing 1. The heat injection tube column includes, from top to bottom, a first insulating oil tube 3, a perforated tube 8, and a second insulating oil tube 9. A high-temperature packer 7 is provided between the first insulating oil tube 3 and the casing 1. The high-temperature packer 7 is equipped with a vent valve 6. The high-temperature packer 7 divides the outer heat injection tube column and the casing 1 into upper and lower annular sections. When the vent valve 6 is opened, gas can enter the area below the high-temperature packer 7 through the vent valve 6. The annulus between the first heat-insulating oil pipe 3 and the casing 1; the perforated pipe 8 is provided with a first guiding flow hole, which is used to connect the inner cavity of the perforated pipe 8 with the annulus of the outer heat injection string and the casing 1; the second heat-insulating oil pipe 9 is provided with a deep well safety valve 10; the second heat-insulating oil pipe 9 below the deep well safety valve 10 extends into the sand control string 11 and is sealed by positioning and sealing; the diameter of the first heat-insulating oil pipe 3 is larger than the diameter of the second heat-insulating oil pipe 9, which facilitates the lowering and lowering of the production string.

[0041] The production string is adapted to be inserted into the first insulated tubing 3. The production string includes, from top to bottom, a small tubing 13, an EDG connector 16, and an inverted EDG. An upper production packer 15 is provided between the small tubing 13 and the first insulated tubing 3, which, during setting, seals the annulus between the first insulated tubing 3 and the small tubing 13 into upper and lower parts. A lower production packer 25 is provided between the inverted EDG and the first insulated tubing 3, which, during setting, seals the annulus between the first insulated tubing 3 and the inverted EDG into upper and lower parts. The EDG connector 16 is provided with a second guide hole 16-2, which connects the inner cavity of the small tubing 13 with the annulus between the outer heating tubing and the inner production tubing.

[0042] When injecting hot fluid, such as Figure 3 As shown, the hot fluid flows through the first insulated oil pipe 3, the perforated pipe 8, the second insulated oil pipe 9, the deep well safety valve 10, and the second insulated oil pipe 9 to the formation.

[0043] When injecting air, if Figure 4 As shown, the gas passes through the tree valve, the annulus of the first insulated tubing 3 and casing 1, the vent valve 6, the annulus of the first insulated tubing 3 and casing 1, the perforated pipe 8, the second insulated tubing 9, the deep well safety valve 10, and the second insulated tubing 9 to the formation. This embodiment relies on the existing tree structure design, and the tree is an existing structure, so it will not be described in detail here.

[0044] When producing through the inner production column, such as Figure 5 As shown, the formation produced fluid is produced through the formation, the second insulated tubing 9, the deep well safety valve 10, the second insulated tubing 9, the perforated tubing 8, the inverted electric submersible pump, the annulus of the inverted electric submersible pump and the first insulated tubing 3, the electric submersible pump connector 16, and then to the small tubing 13.

[0045] This embodiment achieves the steam injection-production conversion process through a single-stage tubing operation, involving fewer surface equipment, resulting in high operational efficiency and saving operational resources and costs. The use of a small tubing 13 as the production fluid outlet avoids fluid immersion and scouring in the annular space between the inner production tubing and the outer heat injection tubing, protecting the insulation performance of the insulated tubing and the insulation performance of the cable 14, thus reducing the risk of failure. The ESP unit adopts an inverted pump design, with the cable 14 directly connected to the ESP motor 17 after passing through the upper production packer 15, reducing the risk of cable 14 breakage and improving the operational stability of the ESP in highly deviated wells. The small tubing 13 has strong deployment and retrieval capabilities, enabling ESP deployment and retrieval in highly deviated and horizontal wells.

[0046] Optionally, such as Figure 2 As shown, the electric submersible pump connector 16 includes an upper connecting pipe 16-1 and a lower connecting pipe 16-3. The upper connecting pipe 16-1 is provided with an upper interface for connecting to a small oil pipe 13. The side wall of the upper connecting pipe 16-1 is provided with a second guide hole 16-2. The lower connecting pipe 16-3 is provided with a lower interface for connecting to an inverted electric submersible pump. A partition plate is provided between the upper connecting pipe 16-1 and the lower connecting pipe 16-3, and the partition plate prevents the upper connecting pipe 16-1 and the lower connecting pipe 16-3 from communicating.

[0047] Optionally, the inverted electric submersible pump includes, from top to bottom, a motor 17, a protector 18, a centrifugal pump outlet 20, a centrifugal pump 21, a centrifugal pump inlet 22, and a guide pipe 23. The motor 17 is connected to the lower interface of the lower connecting pipe 16-3. The centrifugal pump outlet 20 is used to connect the centrifugal pump 21 with the annulus between the outer heat injection tube column and the inner production tube column. The centrifugal pump inlet 22 is used to connect the inner cavity of the guide pipe 23 and the centrifugal pump 21. A gas separator 24 is provided on the guide pipe 23. The gas separator 24 separates the gas in the formation produced fluid and guides the liquid through the guide pipe 23 to the centrifugal pump inlet 22.

[0048] like Figure 5 As shown, the formation produced fluid passes through the formation, the second insulated tubing 9, the deep well safety valve 10, the second insulated tubing 9, the perforated pipe 8, the guide pipe 23, the centrifugal pump inlet 22, the centrifugal pump 21, the centrifugal pump outlet 20, the inverted electric submersible pump and the annulus of the first insulated tubing 3, and the electric submersible pump connector 16 to the small tubing 13 for production.

[0049] Optionally, the lower production packer 25 is located outside the guide pipe 23, below the gas separator 24 and above the perforated pipe 8. The lower production packer 25, located below the gas separator 24, allows the gas separated by the gas separator 24 to be discharged into the annulus of the inverted pump-first insulated oil pipe 3. This embodiment optimizes the flow path of the produced fluid, ensuring that gas in the produced fluid can be discharged in a timely manner, preventing gas accumulation at the electric submersible pump location that could lead to unstable production or gas lock.

[0050] Optionally, both the upper production packer 15 and the lower production packer 25 employ hydraulic setting and lifting of the tubing string for unsealing. The upper production packer 15 has a slipless design. The upper production packer 15 and the lower production packer 25 share a single production packer hydraulic control line 19, and are communicatively connected to ground control equipment via the production packer hydraulic control line 19.

[0051] Optionally, the high-temperature packer 7 is hydraulically set and unsealed by lifting the tubing string. The high-temperature packer 7 is connected to the ground control equipment via the high-temperature packer hydraulic control line 5. The venting valve 6 is connected to the ground control equipment via the venting valve hydraulic control line 4. The deep well safety valve 10 is connected to the ground control equipment via the deep well safety valve hydraulic control line 26.

[0052] Optionally, the first insulated oil pipe 3 is sealed and suspended inside the casing 1 by the large oil pipe hanger 2, and the small oil pipe 13 is sealed and suspended at the four-way position of the wellhead by the small oil pipe hanger 12. In this embodiment, the wellhead is an existing structure.

[0053] Optionally, the high-temperature packer hydraulic control line 5, the deep well safety valve hydraulic control line 26, and the vent valve hydraulic control line 4 are fixed to the outer wall of the first insulated tubing 3 by a pipeline protector, pass through the large tubing hanger 2, and then pass through the Christmas tree as a whole. The production packer hydraulic control line 19 and the cable 14 of the inverted electric submersible pump are fixed to the outer wall of the small tubing 13 by a pipeline protector, pass through the small tubing hanger 12, and then pass through the Christmas tree as a whole.

[0054] This embodiment also provides a method for implementing the aforementioned integrated heavy oil injection and production system using a small tubing 13 to deploy an electric pump, comprising:

[0055] S1: Open the deep well safety valve 10 and the venting valve 6, set the high-temperature packer 7, and inject hot fluid into the well using the heating tubing string. Inject gas into the annulus of the heating tubing string and casing 1. When injecting hot fluid, the hot fluid passes through the first insulated oil pipe 3, the perforated pipe 8, the second insulated oil pipe 9, the deep well safety valve 10, and the second insulated oil pipe 9 to the formation. When injecting gas, the gas passes through the production tree valve, the annulus of the first insulated oil pipe 3 and casing 1, the venting valve 6, the annulus of the first insulated oil pipe 3 and casing 1, the perforated pipe 8, the second insulated oil pipe 9, the deep well safety valve 10, and the second insulated oil pipe 9 to the formation. After the heating is completed, the process proceeds to the well shut-in and blowout stages in sequence. During the blowout stage, the formation fluid is ejected to the wellhead through the heating tubing string. In this embodiment, the gas is nitrogen. This application does not limit the specific type of gas.

[0056] S2: After the blowout is completed, the inverted pump is inserted into the first insulated tubing 3 through the small tubing 13, the upper production packer 15 and the lower production packer 25 are set, the pump is started and production is carried out, the produced fluid is lifted to the wellhead, the formation produced fluid passes through the formation, the second insulated tubing 9, the deep well safety valve 10, the second insulated tubing 9, the perforated pipe 8, the guide pipe 23, the centrifugal pump inlet 22, the centrifugal pump 21, the centrifugal pump outlet 20, the inverted electric submersible pump and the annulus of the first insulated tubing 3, and the electric submersible pump connector 16 to the small tubing 13 for production;

[0057] S3: When the output of the electric submersible pump decreases to the economic output, stop the pump, release the upper production packer 15 and the lower production packer 25, and remove the inverted pump unit through the small oil pipe 13.

[0058] S4: Repeat step S1 again.

[0059] Optionally, when engaging or disengaging the inverted pump unit, the moving tubing operation can be completed using a workover rig via the small tubing 13.

[0060] For ease of explanation, spatial relative terms such as "upper," "lower," "outer," and "inner" are used in the embodiments to describe the relationship of one element or feature relative to another element or feature shown in the figures. It should be understood that, in addition to the orientations shown in the figures, spatial terms are intended to include different orientations of the device during use or operation. Therefore, the exemplary term "lower" can encompass both upper and lower orientations.

[0061] Moreover, relational terms such as “3” and “4” are merely used to distinguish one component from another that has the same name, without necessarily requiring or implying any such actual relationship or order between the components.

[0062] Although preferred embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not limiting. Those skilled in the art can make many specific modifications under the guidance of the present invention without departing from the spirit of the invention and the scope of protection of the claims, and these modifications all fall within the scope of protection of the present invention.

Claims

1. A system for realizing the integrated injection and production of heavy oil by using a small oil pipe to cast an electric pump, characterized in that: include: A heat injection string, the heat injection string is arranged in the casing, the heat injection string comprises from top to bottom a first heat-insulated oil pipe, a perforated pipe and a second heat-insulated oil pipe, a high-temperature packer is arranged between the first heat-insulated oil pipe and the casing, a venting valve is arranged on the high-temperature packer, a first guide flow hole is arranged on the perforated pipe, the first guide flow hole is used to connect the inner cavity of the perforated pipe with the outer heat injection string and the casing annulus, a deep well safety valve is arranged on the second heat-insulated oil pipe, the second heat-insulated oil pipe below the deep well safety valve extends into the sand control string, and the diameter of the first heat-insulated oil pipe is greater than the diameter of the second heat-insulated oil pipe; A production tubing string, the production tubing string is suitable for being lowered into the first insulated oil pipe, the production tubing string comprises from top to bottom a small oil pipe, an electric submersible pump connector and an inverted electric submersible pump, an upper production packer is provided between the small oil pipe and the first insulated oil pipe, a lower production packer is provided between the inverted electric submersible pump and the first insulated oil pipe, and a second guide hole is provided on the electric submersible pump connector, the second guide hole is used to connect the inner cavity of the small oil pipe with the outer heat injection tubing string and the inner production tubing string annulus; When injecting hot fluid, the hot fluid passes through the first insulated oil pipe, the perforated pipe, the second insulated oil pipe, the deep well safety valve, and the second insulated oil pipe to the formation; During gas injection, the gas passes through the tree wing valve, the first insulated tubing and casing annulus, the vent valve, the first insulated tubing and casing annulus, the perforated pipe, the second insulated tubing, the deep well safety valve, and the second insulated tubing to the formation; When producing through the inner production tubing, the formation production fluid passes through the formation, the second insulated oil pipe, the deep well safety valve, the second insulated oil pipe, the perforated pipe, the inverted electric submersible pump, the inverted electric submersible pump and the annulus of the first insulated oil pipe, and the electric submersible pump connector to the small oil pipe for production.

2. The system for realizing integrated injection and production of heavy oil by using a small oil pipe and electric pump according to claim 1, characterized in that: The electric submersible pump connector includes an upper connecting pipe and a lower connecting pipe, the upper connecting pipe is provided with an upper interface for connecting a small oil pipe, the side wall of the upper connecting pipe is provided with the second guide flow hole, the lower connecting pipe is provided with a lower interface for connecting an inverted electric submersible pump, and a partition plate is provided between the upper connecting pipe and the lower connecting pipe.

3. The system for realizing integrated injection and production of heavy oil by using a small oil pipe and electric pump according to claim 2, characterized in that: The inverted electric submersible pump comprises, from top to bottom, a motor, a protector, a centrifugal pump outlet, a centrifugal pump, a centrifugal pump inlet and a flow guide pipe, wherein the motor is connected to the lower interface of the lower connecting pipe, the centrifugal pump outlet is used to connect the centrifugal pump with the outer heat injection pipe string and the inner production pipe string annulus, the centrifugal pump inlet is used to connect the inner cavity of the flow guide pipe and the centrifugal pump, and a gas separator is provided on the flow guide pipe; The formation produced fluid is produced through the formation, the second insulated oil pipe, the deep well safety valve, the second insulated oil pipe, the perforated pipe, the guide pipe, the centrifugal pump inlet, the centrifugal pump, the centrifugal pump outlet, the inverted electric submersible pump and the first insulated oil pipe annulus, and the electric submersible pump connector to the small oil pipe.

4. The system for realizing integrated injection and production of heavy oil by using a small oil pipe to cast and scoop an electric pump according to claim 3, characterized in that: The lower production packer is arranged outside the flow guide pipe and is located below the gas separator and above the perforated pipe.

5. The system for realizing integrated injection and production of heavy oil by using a small oil pipe to cast and scoop an electric pump according to claim 1, characterized in that: The upper production packer and the lower production packer are both hydraulically sealed and unsealed by lifting the pipe string. The upper production packer and the lower production packer share a production packer hydraulic control pipeline. The upper production packer and the lower production packer are communicatively connected with the ground control equipment through the production packer hydraulic control pipeline.

6. The system for realizing integrated injection and production of heavy oil by using a small oil pipe to cast and scoop an electric pump according to claim 5, characterized in that: The high-temperature packer is hydraulically sealed and unsealed by lifting the pipe string. The high-temperature packer is communicatively connected to the ground control equipment via the high-temperature packer hydraulic control pipeline. The air release valve is communicatively connected to the ground control equipment via the air release valve hydraulic control pipeline. The deep well safety valve is connected to the ground control equipment via the deep well safety valve hydraulic control pipeline.

7. The system for realizing integrated injection and production of heavy oil by using a small oil pipe to cast and scoop an electric pump according to claim 6, characterized in that: The first heat-insulated oil pipe is sealed and suspended in the casing through a large oil pipe hanger, and the small oil pipe is sealed and suspended at the spool position of the Christmas tree through a small oil pipe hanger.

8. The system for realizing integrated injection and production of heavy oil by using a small oil pipe to cast and scoop an electric pump according to claim 7, characterized in that: The high-temperature packer hydraulic control pipeline, deep well safety valve hydraulic control pipeline, and bleed valve hydraulic control pipeline are fixed to the outer wall of the first insulated oil pipe through pipeline protectors, pass through the large oil pipe hanger and then pass through the entire Christmas tree. The production packer hydraulic control pipeline and the cable of the inverted electric submersible pump are fixed to the outer wall of the small oil pipe through pipeline protectors, pass through the small oil pipe hanger and then pass through the entire Christmas tree.

9. A method for realizing a heavy oil injection and production integrated system by using a small oil pipe to cast and scoop an electric pump as described in any one of claims 1 to 8, characterized in that: include: S1: Open the deep well safety valve and the bleed valve, seal the high-temperature packer, use the heat injection string to inject hot fluid into the well, and use the heat injection string and the casing annulus to inject gas. When injecting hot fluid, the hot fluid passes through the first insulated oil pipe, the perforated pipe, the second insulated oil pipe, the deep well safety valve, and the second insulated oil pipe to the formation; when injecting gas, the gas passes through the Christmas tree wing valve, the first insulated oil pipe and the casing annulus, the bleed valve, the first insulated oil pipe and the casing annulus, the perforated pipe, the second insulated oil pipe, the deep well safety valve, and the second insulated oil pipe to the formation. After the heat injection is completed, the well is sequentially turned into the soaking and blowing stages. In the blowing stage, the formation fluid is sprayed to the wellhead through the heat injection string; S2: After the blowout is completed, the inverted pump is put into the first insulated tubing through the small tubing, the upper production packer and the lower production packer are set, the pump is started for production, the produced fluid is lifted to the wellhead, and the formation produced fluid is produced through the formation, the second insulated tubing, the deep well safety valve, the second insulated tubing, the perforated pipe, the flow guide pipe, the centrifugal pump inlet, the centrifugal pump, the centrifugal pump outlet, the inverted electric submersible pump and the annulus of the first insulated tubing, and the electric submersible pump connector to the small tubing; S3: When the output of the ESP drops to the economic output, the pump is stopped, the upper production packer and the lower production packer are unsealed, and the inverted pump unit is pulled out through the small tubing; S4: Repeat step S1 again.

10. The method for realizing an integrated system of heavy oil injection and production by using a small oil pipe to cast and scoop an electric pump according to claim 9, characterized in that: When the inverted pump unit is put in and taken out through a small oil pipe, the pipe moving operation is completed by the workover rig.

Images