Fishing electric pump oil production process pipe column

Abstract

This invention relates to a tubing string for a submersible electric pump (SPMP) oil production process, comprising a production casing and an inner tubing string disposed within the production casing. The inner tubing string can be lowered to a predetermined position by a winch. A venting submersible joint is connected to the lower end of the production casing, connecting the annulus inside the production casing to the annulus outside the production casing. The inner tubing string includes a submersible electric pump (SPMP) and an electric pump suspension packer connected to the upper end of the SPMP. The electric pump suspension packer has an oil flow channel for oil circulation. The venting submersible joint is located between the electric pump suspension packer and the SPMP inlet. This invention, through the venting submersible joint, can vent the gas released at the SPMP inlet to the annulus outside the production casing, solving the problem of gas affecting the pump efficiency of the SPMP. It can be used in oil wells with high gas content. Furthermore, the inner tubing string of this invention can be lowered to a predetermined position by a winch, offering significant economic advantages and adaptability.

Description

Technical Field

[0001] This invention belongs to the field of petroleum extraction technology, specifically relating to a tubing string for an electric pump oil recovery process. Background Technology

[0002] Submersible electric pumps (SAPs) are currently the most widely used artificial lift method in offshore oilfields. Conventional oil production processes require connecting the SSP unit to the lower end of the tubing. During initial pump deployment or maintenance operations, both the tubing and SSP must be retrieved using a drill-workover module. This results in long operation cycles, low efficiency, and high well workover costs, impacting the economic viability of oilfield development. With the increasing number of rigless submersible pump platforms in offshore marginal oilfields, maintenance of pumps on these platforms requires the use of workover vessels. This leads to high workover vessel operation costs and a scarcity of workover vessels, often resulting in long waiting times or even well abandonment. Therefore, there is an urgent need for a pump deployment and retrieval technology that eliminates the need for workover rigs or vessels to meet the development and exploitation needs of marginal oilfields.

[0003] High gas content in offshore oil wells and difficulty in venting are common problems in the deployment and recovery of electric submersible pumps (ESPs). The root cause lies in the low pressure near the ESP inlet, where free gas easily precipitates from the crude oil and accumulates in the annulus between the ESP inlet (below the ESP suspension seal) and the large-diameter production casing. Since there are no dedicated venting channels inside or outside the production casing, as the gas pressure gradually increases, not only does the dynamic fluid level inside the production casing drop, but the proportion of gas drawn into the pump also increases significantly, reducing ESP efficiency and ultimately causing gas lock. Currently, the offshore deployment and recovery ESP process mainly uses an automatic pressure relief valve (ADV valve) connected between the ESP suspension seal and the ESP for venting. However, the venting effect is unsatisfactory, requiring frequent pump shutdowns for venting, which seriously affects normal production and unit lifespan. Therefore, solving the venting problem is a key technical challenge for the widespread application of the deployment and recovery ESP process. Summary of the Invention

[0004] To address all or part of the aforementioned problems, the present invention aims to provide a submersible electric pump (SAP) oil production process tubing. By incorporating an exhaust vent, the gas emanating from the SSP's inlet can be discharged to the annulus outside the production casing, thus resolving the issue of gas affecting the SSP's pump efficiency and improving production efficiency. Furthermore, the inner tubing of the present invention can be lowered to a predetermined position using a winch, thereby possessing significant economic advantages and adaptability.

[0005] According to one aspect of the present invention, a submersible electric pump (SAP) oil production process tubing is provided, comprising a production casing, an inner tubing within the production casing, the inner tubing including a submersible electric pump and an electric pump suspension packer connected to the upper end of the SSP, the electric pump suspension packer having an oil flow channel for oil circulation, the outlet of the SSP communicating with the oil flow channel, and the inner tubing being lowered to a predetermined position by a winch;

[0006] The lower end of the production casing is connected to an exhaust stub, which connects the annulus inside the production casing with the annulus outside the production casing. The exhaust stub is located between the electric pump suspension packer and the suction port of the submersible electric pump.

[0007] Furthermore, the upper end of the electric pump suspension packer is provided with a connecting joint, and a cable is connected to the connecting joint so that the inner tube column can be lowered to a predetermined position through the cable and the winch.

[0008] Furthermore, the cable includes a cable core and armored steel wires located on the outer layer of the cable core, the cable core being used to supply power to the submersible pump; the pump suspension packer has a through hole inside, the through hole being used for the cable core to pass through.

[0009] Furthermore, the electric pump suspension packer is also provided with a cable docking chamber, which divides the through hole into upper and lower parts. The cable core passes through the through hole in the upper part of the cable docking chamber, and the cable of the submersible electric pump passes through the through hole in the lower part of the cable docking chamber. The cable core is connected to the cable of the submersible electric pump in the cable docking chamber.

[0010] Furthermore, a first hydraulic control line is also provided inside the armored steel wire. The first hydraulic control line is connected to the electric pump suspension packer so that the electric pump suspension packer can be set or unsealed by pressurizing through the first hydraulic control line.

[0011] Furthermore, it also includes a female and a male through-connector. The female through-connector is used to connect to the cable core of the cut cable. The female through-connector is built into the wire cable hanger, and the wire cable hanger is connected to the cable. The wire cable hanger is fixed in the riser section of the tree trunk. The male through-connector extends through the lateral hole of the riser section to mate with the female through-connector. The cable core passes through the male through-connector and extends out of the tree trunk.

[0012] Furthermore, the wire cable hanger is located within the main channel of the riser section, and the riser section and the wire cable hanger are sealed together; the riser section has a bypass fluid flow channel.

[0013] Furthermore, the venting short section is a venting sliding sleeve, which has a venting side hole. The venting sliding sleeve is connected to a second hydraulic control line, so that the venting side hole can be opened by pressurizing the second hydraulic control line, or the venting side hole can be closed by depressurizing the second hydraulic control line; or, the venting short section is an oil pipe short section with a venting side hole.

[0014] Furthermore, a gas-liquid separator is connected to the lower end of the submersible electric pump. The gas-liquid separator is used to separate oil and gas. The oil separated by the gas-liquid separator is drawn into the suction port of the submersible electric pump.

[0015] Furthermore, the production casing is located inside the outer casing, and the lower end of the venting short section is connected from top to bottom to a set-in connector outer cylinder, an oil pipe, a safety valve, and a positioning insertion seal. A top packer is installed inside the outer casing, and the positioning insertion seal cooperates with the top packer. An oil pipe hanger is connected to the upper end of the production casing, and the oil pipe hanger is suspended inside the oil pipe cross. The safety valve is connected to a third hydraulic control line.

[0016] As can be seen from the above technical solution, the drop-out electric pump oil production process tubing provided by the present invention has the following beneficial effects:

[0017] This invention, through the design of the exhaust stub, enables the gas released at the inlet of the submersible electric pump to be discharged to the annulus outside the production casing, solving the problem of the submersible electric pump's efficiency being affected by the presence of gas, thus improving production efficiency and ensuring the stable operation of the unit. It can be used in oil wells with high gas content. Secondly, the inner tubing of this invention can be lowered to a predetermined position by a winch, meeting the needs of rapid production and pump maintenance operations on offshore well-tampering platforms, and possessing good economic advantages and adaptability. Attached Figure Description

[0018] Figure 1 This is a cross-sectional view of the tubing string for the drop-out electric pump oil production process according to an embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of the operation of lowering the outer tubing into the production casing;

[0020] Figure 3 This is a schematic diagram of the operation of lowering the inner tubular column;

[0021] Figure 4 This is a cross-sectional structural diagram of the cable according to an embodiment of the present invention;

[0022] Figure 5 This is a schematic diagram of the venting process of the tubing in the electric pump oil recovery process according to an embodiment of the present invention.

[0023] The attached diagram is labeled as follows: 1. Wellhead, 2. Raise section, 3. Tubing four-way connector, 4. Wire cable hanger, 5. Through female connector, 6. Through male connector, 7. Outer casing, 8. Production casing, 9. Vent section, 10. Settling joint outer cylinder, 11. Tubing, 12. Safety valve, 13. Positioning insert seal, 14. Top packer, 15. Cable, 16. EV pump suspension packer, 17. EV pump, 18. Gas-liquid separator, 19. Protector, 20. Second hydraulic control line, 21. Third hydraulic control line, 22. Drilling and workover module, 23. Winch, 24. Cable core, 25. First hydraulic control line, 26. Armored wire, 27. Vent side hole, 28. Detailed Implementation

[0024] To better understand the purpose, structure, and function of this invention, the following detailed description of a drop-out electric pump oil recovery process string of this invention is provided in conjunction with the accompanying drawings.

[0025] like Figure 1 As shown, this invention illustrates a deployment and retrieval electric pump (EPP) oil production process tubing, including a production casing 9. An inner tubing string is installed inside the production casing 9, comprising a submersible electric pump 18 and an electric pump suspension packer 17 connected to the upper end of the submersible electric pump 18. The electric pump suspension packer 17 has an oil flow channel for oil circulation. The outlet of the submersible electric pump 18 is connected to the oil flow channel. The inner tubing string can be lowered to a predetermined position by a winch. An venting section 10 is connected to the lower end of the production casing 9, connecting the annulus inside the production casing 9 and the annulus outside the production casing 9. The venting section 10 is located between the electric pump suspension packer 17 and the suction port of the submersible electric pump 18.

[0026] Specifically, the tubing string in this embodiment includes a production casing 9 and an inner tubing string disposed within the production casing 9. The inner tubing string specifically includes a submersible electric pump 18 and an electric pump suspension packer 17. The electric pump suspension packer 17 has suspension slips and an expansion sealing sleeve. When pressurized through the hydraulic control line, the electric pump suspension packer 17 can be seated on the inner wall of the production casing 9. Similarly, it can be released after being pressurized to a higher pressure value. The submersible electric pump 18 is used for oil production. The electric pump suspension packer 17 has an oil flow channel for oil circulation. The outlet of the submersible electric pump 18 is connected to the oil flow channel, so that the oil sucked in by the submersible electric pump 18 can be lifted through the oil flow channel to the top of the electric pump suspension packer 17, and finally lifted into the manifold of the surface-deployed electric pump-specific production tree.

[0027] Secondly, the inner tubing string can be lowered to the predetermined position by a winch. Therefore, the lowering of the inner tubing string does not require the participation of the drilling and workover module, meeting the rapid production and pump maintenance needs of offshore workover rig-less platforms, and possessing good economic advantages and adaptability. In specific implementation, for example, the inner tubing string is connected to cable 16, thereby lowering the inner tubing string to the predetermined position via cable 16 and winch 24. Figure 3 As shown.

[0028] Furthermore, the lower end of the production casing 9 is connected to an exhaust stub 10, which is located between the electric pump suspension packer 17 and the suction inlet of the submersible electric pump 18. Therefore, free gas generated at the suction inlet of the submersible electric pump 18 can be discharged to the annulus outside the production casing 9 through the exhaust stub 10. This solves the problem of the submersible electric pump 18's pump efficiency being affected by the presence of gas, improves production efficiency, ensures stable operation of the unit, and can be used in oil wells with high gas content. In specific implementation, a protector 20 can be installed at the lower end of the submersible electric pump 18 as needed.

[0029] In one specific embodiment, a gas-liquid separator 19 is connected to the lower end of the submersible electric pump 18. The gas-liquid separator 19 is used to separate oil and gas. The oil separated by the gas-liquid separator 19 is sucked into the suction port of the submersible electric pump 18.

[0030] In this embodiment, the gas-liquid separator 19 is used to separate oil and gas, thereby reducing the gas content in the oil. The oil separated by the gas-liquid separator 19 is drawn into the suction port of the submersible pump 18, thereby lifting the oil. This embodiment can be used in oil wells with high gas content.

[0031] In one specific embodiment, the upper end of the electric pump suspension packer 17 is provided with a connecting joint, and a cable 16 is connected to the connecting joint so that the inner tube column can be lowered to a predetermined position through the cable 16 and the winch.

[0032] Specifically, in this embodiment, a connecting connector is provided at the upper end of the electric pump suspension packer 17. The cable 16 can be connected to the electric pump suspension packer 17 through the connecting connector. By connecting the cable 16 to the winch, the purpose of lowering the inner tube column to the predetermined position can be achieved by the winch.

[0033] In one specific embodiment, such as Figure 4 As shown, the cable 16 includes a cable core 25 and an armored steel wire 27 located on the outer layer of the cable core 25. The cable core 25 is used to supply power to the submersible electric pump 18. The electric pump suspension packer 17 is provided with a through hole for the cable core 25 to pass through.

[0034] In this embodiment, cable 16 includes cable core 25 and armored steel wire 27. This allows the inner tubing to be lowered to a predetermined position via a winch, and also enables the transmission of ground power to the submersible electric pump 18 via the cable core 25, thus powering the submersible electric pump 18. The corresponding pump suspension packer 17 has through holes for the cable core 25 to pass through. In practice, the armored steel wire 27 can be layered as needed to achieve high tensile strength. Cable 16 must be able to withstand the weight of the submersible electric pump 18 unit and the weight of the entire cable 16.

[0035] In one specific embodiment, the electric pump suspension packer 17 is further provided with a cable docking chamber. The cable docking chamber divides the through hole into upper and lower parts. The cable core 25 passes through the through hole in the upper part of the cable docking chamber, and the cable of the submersible electric pump 18 passes through the through hole in the lower part of the cable docking chamber. The cable core 25 is connected to the cable of the submersible electric pump 18 in the cable docking chamber.

[0036] In this embodiment, the cable core 25 and the cable of the submersible pump 18 are connected within a cable docking chamber located inside the pump suspension packer 17. Specifically, the cable docking chamber is located inside the pump suspension packer 17, and the through hole is divided into upper and lower parts. The cable core 25 passes through the through hole in the upper part of the cable docking chamber, while the small flat cable of the submersible pump 18 passes through the through hole in the lower part of the cable docking chamber. The cable core 25 connects with the small flat cable within the cable docking chamber, and a seal is provided at the connection point. In specific implementations, the through hole and the oil flow channel can be set to be the same as needed.

[0037] In one specific embodiment, such as Figure 4 As shown, a first hydraulic control line 26 is also provided inside the armored steel wire 27. The first hydraulic control line 26 is connected to the electric pump suspension packer 17 so that the electric pump suspension packer 17 can be set or unsealed by pressurizing the first hydraulic control line 26.

[0038] In this embodiment, a first hydraulic control line 26 is also provided inside the armored steel wire 27, so that the setting or unsealing of the electric pump suspension packer 17 can be controlled through the first hydraulic control line 26. Specifically, after the inner tube is lowered to the predetermined position, the electric pump suspension packer 17 can be set by pressurizing through the first hydraulic control line 26. When the pressure is increased to a higher pressure value through the first hydraulic control line 26, the electric pump suspension packer 17 is immediately unsealed.

[0039] The cable 16 in this embodiment has high tensile strength and is lighter than the continuous tubing composite cable. The drum winch is small in size and light in weight, and has lower requirements for working space and equipment, making it more suitable for promotion and application on workover rig-less platforms.

[0040] In one specific embodiment, the venting sub 10 is a venting slide sleeve with a venting side hole 28. The venting slide sleeve is connected to a second hydraulic control line 21 so that the venting side hole 28 can be opened by pressurizing the second hydraulic control line 21, or the venting side hole 28 can be closed by depressurizing the second hydraulic control line 21; or, the venting sub 10 is an oil pipe sub with a venting side hole.

[0041] In this embodiment, the venting sub-section 10 is a venting sliding sleeve with a venting side hole; or the venting sub-section 10 is an oil pipe sub-section with a venting side hole; thereby achieving the purpose of connecting the external annulus of the production casing 9 and the internal annulus of the production casing 9 below the electric pump suspension packer 17. When the venting sub-section 10 is a venting sliding sleeve, the venting side hole of the venting sliding sleeve can be opened or closed through the second hydraulic control line 21.

[0042] In the prior art, during the normal start-up and operation of the tubing string, the pressure drop near the suction port of the submersible electric pump 18 can easily cause free gas to be released from the crude oil. This gas rises and accumulates in the production casing 9 below the sealing rubber sleeve of the electric pump suspension packer 17 and above the suction port of the submersible electric pump 18. As the amount of gas increases, the gas pressure and volume gradually increase, and eventually the gas pressure will cause the crude oil level to drop. In this embodiment, the venting sub-section 10 is located between the electric pump suspension packer 17 and the suction inlet of the submersible electric pump 18. If the venting sub-section 10 is a tubing sub-section with a venting side hole, the generated gas can directly escape through the venting side hole to the annulus outside the production casing 9. At the same time, the liquid in the annulus outside the production casing 9 can enter the production casing 9 through the venting side hole to replenish the liquid level. If the venting sub-section 10 is a venting sliding sleeve, since the venting side hole of the venting sliding sleeve is normally closed, it is necessary to pressurize through the second hydraulic control line 21 to open the venting side hole of the venting sliding sleeve, so as to realize the conduction of the annulus inside and outside the production casing 9, thereby realizing the automatic discharge of gas. After the venting is completed, the venting side hole can be restored to the closed state by depressurizing through the second hydraulic control line 21. Figure 5 The middle exhaust short section 10 is the exhaust sliding sleeve, which is connected to the second hydraulic control line 21, through which gas flows... Figure 5 The gas overflows from the exhaust side hole into the outer annulus of the production casing 9. This achieves automatic gas discharge, improves the pumping efficiency of the submersible electric pump 18, and avoids air lock.

[0043] In one specific embodiment, the production casing 9 is located inside the outer casing 8. The lower end of the venting stub 10 is connected from top to bottom to the outer cylinder 11 of the set-in connector, the oil pipe 12, the safety valve 13, and the positioning insertion seal 14. A top packer 15 is provided inside the outer casing 8. The positioning insertion seal 14 and the top packer 15 cooperate with each other. The upper end of the production casing 9 is connected to the oil pipe hanger 5, which is suspended inside the oil pipe cross 3. The safety valve 13 is connected to the third hydraulic control line 22.

[0044] Specifically, the production casing 9, venting sub 10, landing joint outer cylinder 11, tubing 12, safety valve 13, and positioning insertion seal 14 are collectively referred to as the outer tubing string. The outer tubing string is installed inside the casing. Before the initial well completion of the process tubing string composed of the outer and inner tubing strings, a top packer 15 needs to be pre-installed in the bottom sand control section of the outer casing 8. When installing the outer tubing string, the positioning insertion seal 14, safety valve 13, tubing 12, landing joint outer cylinder 11, venting sub 10, and production casing 9 are sequentially installed from bottom to top using the drill-workover module 23. Figure 2 As shown. The positioning and sealing 14 at the end of the outer tubing string is inserted into the top packer 15 for positioning and sealing. Finally, the upper end of the outer tubing string is connected to the tubing hanger 5 and suspended in the tubing cross 3.

[0045] The top packer 15 is used to set the annulus between the outer sleeve 8 and the production sleeve 9. The safety valve 13 is used in abnormal situations, and its opening or closing is achieved by pressurizing or depressurizing through the third hydraulic control line 22.

[0046] After the outer tubing string is lowered and the top packer 15 sets the annulus between the outer tubing string and the outer sleeve 8, a pressure test is required. When the venting sub 10 is a venting sleeve, the venting side hole of the venting sleeve is normally closed. Therefore, the annulus outside the production casing 9 and the annulus inside the production casing 9 are not connected, and a pressure test can be performed directly on the annulus outside the production casing 9. If a pressure test is to be performed on the annulus inside the production casing 9, the plug matching the outer sleeve 11 of the set-in connector needs to be lowered in advance via wireline operation to plug the outer sleeve 11 of the set-in connector. When the venting sub 10 is a tubing sub with a venting side hole, the annulus outside the production casing 9 and the annulus inside the production casing 9 are connected. Therefore, after the plug matching the outer sleeve 11 of the set-in connector is lowered via wireline operation, a pressure test can be performed.

[0047] After the pressure test is passed, connect the submersible electric pump 18 and the pump suspension packer 17, and lower the inner tubing string to the predetermined position via cable 16.

[0048] In one specific embodiment, it also includes a female through connector 6 and a male through connector 7. The female through connector 6 is used to connect to the cable core 25 of the cut cable 16. The female through connector 6 is built into the wire cable hanger 4, and the wire cable hanger 4 is connected to the cable 16. The wire cable hanger 4 is fixed in the riser section 2 of the tree trunk 1. The male through connector 7 extends through the lateral hole of the riser section 2 to connect with the female through connector 6. The cable core 25 passes through the male through connector 7 and extends out of the tree trunk 1.

[0049] Specifically, the tubing string in this embodiment of the invention further includes a male through connector 7 and a female through connector 6. After the outer tubing string is lowered to the predetermined position, the cable 16 is cut at the wellhead. Then, the armored steel wire 27 on the outer side of the upper cable 16 is stripped, and the cable core 25 is connected to the female through connector 6 and integrated inside the wire cable hanger 4. The cable 16 without stripped armored steel wire 27 is connected to the wire cable hanger 4 through its armored steel wire 27. After completing the connection of the wire cable hanger 4, it is lowered to the predetermined position inside the riser section 2 of the Christmas tree 1, and then the wire cable hanger 4 is fixed inside the riser section 2 of the Christmas tree 1 by tightening the set screw.

[0050] Next, after the wire cable hanger 4 is fixed, the male connector 7 is inserted through the lateral hole of the riser stub 2. The male connector 7 and the female connector 6 cooperate, and the cable core 25 passes through the male connector 7 and extends out of the tree 1, thus realizing the entire cable core 25 of the submersible pump 18 passing through the tree 1.

[0051] In one specific embodiment, the wire cable hanger 4 is located within the main channel of the riser section 2, and the riser section 2 and the wire cable hanger 4 are sealed together; the riser section 2 has a bypass fluid flow channel.

[0052] Specifically, the main channel of the riser section 2 is equipped with a steel wire cable hanger 4 and the upper and lower ends are sealed to prevent liquid from entering the side holes of the riser section 2. The riser section 2 also has a bypass fluid flow channel to allow crude oil to pass through.

[0053] In this embodiment of the invention, the entire process tubing needs to be lowered into the outer tubing in one go via the drilling and workover module. Subsequent operations such as lowering the ESP and maintenance pumps do not require the drilling and workover module; the unit can be quickly retrieved and lowered using only cable 16 and a winch. This meets the needs of rapid production and maintenance pump operations on offshore workover rig-free platforms, demonstrating good economy and adaptability. Cable 16 in this embodiment has high tensile strength and is lighter than coiled tubing composite cables. The drum winch is small in size and light in weight, requiring less space and equipment, making it more suitable for widespread application on workover rig-free platforms. The process tubing in this embodiment completely solves the inherent venting difficulties of traditional ESP process tubing, is applicable to wells with higher gas content, improves production efficiency, and ensures stable unit operation.

[0054] It should be noted that, unless otherwise stated, the technical or scientific terms used in this application should have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0055] Furthermore, the terms "a," "two," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly defined.

[0056] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A tubing string for drop-and-retrieve electric pump oil production, characterized in that, The equipment includes a production sleeve, which contains an inner tube column, which is lowered to a predetermined position by a winch. The lower end of the production casing is connected to an venting section, which connects the annulus inside the production casing to the annulus outside the production casing. The inner tubing string includes a submersible electric pump and an electric pump suspension packer connected to the upper end of the submersible electric pump. The electric pump suspension packer has an oil flow channel for oil circulation. The venting section is located between the electric pump suspension packer and the suction port of the submersible electric pump. The upper end of the electric pump suspension packer is provided with a connecting joint, and a cable is connected to the connecting joint so that the inner tubing string can be lowered to a predetermined position via the cable and a winch. The cable includes an electric... The cable core and the armored steel wire located on the outer layer of the cable core are used to supply power to the submersible pump. The pump suspension packer is provided with a through hole for the cable core to pass through. The pump suspension packer is also provided with a cable docking chamber, which divides the through hole into upper and lower parts. The cable core passes through the through hole in the upper part of the cable docking chamber, and the cable of the submersible pump passes through the through hole in the lower part of the cable docking chamber. The cable core is connected to the cable of the submersible pump in the cable docking chamber. It also includes a female through connector and a male through connector. The female through connector is used to connect to the cable core of the cut cable. The female through connector is built into a steel wire cable hanger, and the steel wire cable hanger is connected to the cable. The wire cable hanger is fixed inside the riser section of the wellhead. The male connector extends through the lateral hole of the riser section to mate with the female connector. The cable core passes through the male connector and extends out of the wellhead. The wire cable hanger is located in the main channel of the riser section, and the riser section and the wire cable hanger are sealed together. The riser section has a bypass fluid flow channel.

2. The drop-and-retrieve electric pump oil recovery tubing string according to claim 1, characterized in that, The armored steel wire is also equipped with a first hydraulic control line, which is connected to the electric pump suspension packer so that the electric pump suspension packer can be set or unsealed by pressurizing the first hydraulic control line.

3. The drop-and-retrieve electric pump oil recovery process tubing according to claim 1, characterized in that, The venting section is a venting slide sleeve with a venting side hole. The venting slide sleeve is connected to a second hydraulic control line so that the venting side hole can be opened by pressurizing the second hydraulic control line, or closed by depressurizing the second hydraulic control line; or, the venting section is an oil pipe section with a venting side hole.

4. The drop-and-retrieve electric pump oil recovery tubing string according to claim 1, characterized in that, The lower end of the submersible electric pump is connected to a gas-liquid separator, which is used to separate oil and gas. The oil separated by the gas-liquid separator is drawn into the suction port of the submersible electric pump.

5. The drop-and-retrieve electric pump oil production process tubing according to claim 1, characterized in that, The production casing is located inside the outer casing. The lower end of the venting sub is provided with, from top to bottom, a set-in connector outer cylinder, an oil pipe, a safety valve, and a positioning insertion seal. A top packer is provided inside the outer casing. The positioning insertion seal and the top packer cooperate with each other. An oil pipe hanger is connected to the upper end of the production casing. The oil pipe hanger is suspended inside the oil pipe cross. The safety valve is connected to a third hydraulic control line.

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