Rodless oil extraction device and method for cable dropping and fishing electric submersible plunger pump

Abstract

The invention discloses a cable throwing and fishing electric submersible plunger pump rodless oil extraction device which comprises an underground rodless oil extraction unit and an inner cable throwing and fishing device which are sequentially arranged in a shaft from bottom to top, the upper end of the inner cable throwing and fishing device is connected with a Christmas tree and a frequency conversion control cabinet, and the Christmas tree and the frequency conversion control cabinet are both located above the shaft. And a cable sealing device is arranged above the Christmas tree. The invention further discloses an oil extraction method of the oil extraction device, the rodless oil extraction unit is tripped, then the throwing-fishing cable is tripped along the interior of an oil pipe, and after the throwing-fishing cable reaches a preset position, a lower connector of the throwing-fishing cable is in accurate butt joint with an upper connector of the throwing-fishing cable, the throwing-fishing cable is connected with the underground unit, a Christmas tree is installed, and data collection is achieved through the sensor. And normal production is carried out. According to the cable throwing and fishing electric submersible plunger pump rodless oil extraction device and the using method thereof, the problems that in the prior art, an armored cable bound outside a steel oil pipe is prone to damage, and the well control risk is high are solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of oil production engineering, and relates to a rodless oil production device of a fishing cable electric submersible plunger pump. The present invention also relates to an oil production method using this device. Background Art

[0002] With the progress of exploration and development technologies for unconventional oil and gas reservoirs, the development in fields such as extra-low permeability, ultra-low permeability, and shale oil has increasingly become dominant. The development mode of large platforms, multiple well types, multiple formations, and three-dimensional development has become inevitable. Traditional rod pumping units in pumping wells face technical problems such as "more rod-tubing eccentric wear failures in large well clusters and less room for efficiency improvement in low-liquid-volume wells".

[0003] Rodless oil production realizes the purpose of lifting and pumping oil by directly driving a submersible pump to reciprocate through a downhole motor. Compared with the rod pumping oil production system of a pumping unit, this process does not require sucker rods, fundamentally solving the problem of rod-tubing eccentric wear commonly existing in cluster wells. Since the intermediate transmission link is omitted, the pump efficiency is improved, further enhancing the system efficiency; the system operation parameters are adjusted by a numerical control method, reducing the system operation and maintenance costs and labor intensity, and realizing intelligent production. However, in the actual use process of rodless oil production devices, there are problems such as easy damage to the armored cable externally bound to the steel tubing and high well control risks. Summary of the Invention

[0004] The purpose of the present invention is to provide a fishing cable electric submersible plunger pump rodless oil production device, which solves the problems of easy damage to the armored cable externally bound to the steel tubing and high well control risks in the prior art.

[0005] Another purpose of the present invention is to provide a method for producing oil using this rodless oil production device.

[0006] The technical solution adopted by the present invention is that the fishing cable electric submersible plunger pump rodless oil production device includes a wellbore. Inside the wellbore, a downhole rodless oil production unit and an internal fishing cable device are successively arranged from bottom to top. The upper end of the internal fishing cable device is respectively connected to a Christmas tree and a variable frequency control cabinet. Both the Christmas tree and the variable frequency control cabinet are located above the wellbore. A cable sealing device is arranged above the Christmas tree. The downhole rodless oil production unit is electrically connected to the variable frequency control cabinet.

[0007] The characteristics of the present invention also lie in that:

[0008] The downhole rodless oil production unit includes a sand control screen pipe. One end of the sand control screen pipe close to the wellhead is connected to an anti-scaling device. A double-packer is sleeved outside the anti-scaling device. The outer wall of the double-packer fits with the inner wall of the wellbore. A downhole sensor is installed on the outer wall of the anti-scaling device. The downhole sensor is electrically connected to the variable frequency control cabinet. One end of the anti-scaling device far from the sand control screen pipe is connected to a linear motor. The output shaft of the linear motor is connected to a plunger pump. The upper end of the plunger pump is connected to the internal fishing cable device.

[0009] The internal fishing cable device includes a fishing cable lower joint. The lower end of the fishing cable lower joint is connected to one end of the plunger pump away from the linear motor. The upper end of the fishing cable lower joint is communicated with an oil pipe. A fishing cable upper joint matching with the fishing cable lower joint penetrates through the oil pipe. The lower end of the fishing cable upper joint penetrates through the fishing cable lower joint and contacts it. The upper end of the fishing cable upper joint is connected to a fishing cable. The upper end of the fishing cable penetrates through the oil pipe and is connected to a frequency conversion control cabinet. The upper end of the oil pipe is communicated with a Christmas tree.

[0010] The fishing cable lower joint includes a connecting seat. The lower end of the connecting seat is connected to the plunger pump. An outer fishing cylinder is fixedly connected above the connecting seat. An inner fishing seal seat matching the inner diameter of the outer fishing cylinder is arranged above the inner part of the outer fishing cylinder. The lower end of the inner fishing seal seat is communicated with an inner fishing insulating pipe. An annular cavity is arranged between the inner fishing insulating pipe and the outer fishing cylinder. A slide rail type rotary guiding track is fixedly connected to the inner wall of the inner fishing insulating pipe. A fishing cable pin is arranged on the connecting seat. One end of the fishing cable pin away from the slide rail type rotary guiding track is connected to a cable lead-out seal joint. The free end of the cable lead-out seal joint penetrates through the side wall of the connecting seat and is connected to the linear motor. The free end of the fishing cable pin penetrates through the lower wall of the inner fishing insulating pipe and faces the inner fishing seal seat.

[0011] The slide rail type rotary guiding track adopts a nib slide rail structure, and the guiding head is arc-shaped.

[0012] The fishing cable pin is made of red copper material, with a peak current carrying capacity of 100A and corrosion resistance L80-13cr.

[0013] The inner fishing insulating pipe adopts a polytetrafluoroethylene insulating material, with a voltage resistance ≥ DC3500V, a temperature resistance ≥ 200°C, and corrosion resistance L80-13cr.

[0014] The fishing cable upper joint includes a weight rod. The lower end of the weight rod penetrates through the inner fishing insulating pipe. The lower end of the weight rod is connected to a fishing cable insulating plug. The free end of the fishing cable insulating plug is connected to the fishing cable pin. A rotary guiding joint matching with the slide rail type rotary guiding track is arranged on the outer wall of the weight rod. The rotary guiding joint is in fit with the slide rail type rotary guiding track. A centralizer is sleeved outside the weight rod. A locking spring seal is arranged on the weight rod. The locking spring seal is located at the connection between the outer fishing cylinder and the weight rod. The upper end of the weight rod is connected to the fishing cable.

[0015] The centralizer is located between the rotary guiding joint and the locking spring seal.

[0016] Another technical solution adopted by the present invention is a method for oil production by an oil production device, which is specifically as follows:

[0017] S1: Lower and install a rodless electrical submersible plunger pump unit, from bottom to top: a sand control screen pipe, an anti-scaling device, a double leather cup packer, a downhole sensor, a linear motor, a plunger pump, a fishing cable lower joint, an oil pipe to the wellhead;

[0018] S2: Lower the fishing cable along the upper end of the tubing, and precisely align the upper connector of the fishing cable at the lower end of the fishing cable with the lower connector of the fishing cable to connect the fishing cable with the downhole unit.

[0019] S3: Install the Christmas tree, conduct system joint debugging, and carry out normal production.

[0020] S4: Through downhole sensors, collect, transmit, and implement an intelligent closed-loop control system for rodless oil production parameters, adaptively control the reasonable flow pressure and rotational speed, and achieve the dynamic balance between production parameters and formation fluid supply.

[0021] The beneficial effects of the present invention are as follows:

[0022] 1. The rodless oil production device with a fishing cable and an electric submersible plunger pump provided by the present invention realizes the docking of the internal fishing cable with the downhole rodless oil production unit, solves the problems of easy damage to the armored cable externally tied to the steel tubing and high well control risk, solves the problem of eccentric wear of the tubing and rod in cluster wells, and improves the efficiency of the oil well system.

[0023] 2. The rodless oil production device with a fishing cable and an electric submersible plunger pump provided by the present invention uses downhole sensors to collect parameters such as downhole pressure in real time, and realizes intelligent production of oil wells by adaptively adjusting the rotational speed of the system. Description of the Drawings

[0024] Figure 1 It is a schematic structural diagram of the rodless oil production device of the present invention;

[0025] Figure 2 It is a schematic structural diagram of the lower connector of the fishing cable of the rodless oil production device of the present invention;

[0026] Figure 3 It is a schematic structural diagram of the upper connector of the fishing cable of the rodless oil production device of the present invention.

[0027] In the figure, 1. Sand control screen pipe, 2. Scale inhibitor, 3. Double cup packer, 4. Downhole sensor, 5. Linear motor, 6. Plunger pump, 7. Lower connector of fishing cable, 7-1. Cable lead-out seal joint, 7-2. Fishing cable plug pin, 7-3. Slide rail type rotary guide track, 7-4. Fishing insulation pipe, 7-5. Fishing outer cylinder, 7-6. Fishing seal seat, 7-7. Connecting seat, 8. Upper connector of fishing cable, 8-1. Fishing cable insulation plug, 8-2. Rotary guide joint, 8-3. Centralizer, 8-4. Locking spring seal, 8-5. Weight rod, 9. Tubing, 10. Fishing cable, 11. Christmas tree, 12. Cable sealing device, 13. Frequency conversion control cabinet. Detailed Embodiments

[0028] The present invention will be described in detail below in conjunction with the drawings and specific embodiments.

[0029] The fishing cable electric submersible plunger pump rodless oil production device, as Figure 1 shown, includes a wellbore. Inside the wellbore, a downhole rodless oil production unit and an internal fishing cable device are successively arranged from bottom to top. The upper end of the internal fishing cable device is respectively connected to a Christmas tree 11 and a variable frequency control cabinet 13. The Christmas tree 11 and the variable frequency control cabinet 13 are both located above the wellbore. A cable sealing device 12 is arranged above the Christmas tree 11. The downhole rodless oil production unit is electrically connected to the variable frequency control cabinet 13. The cable sealing device 12 is used for the gravity suspension of the fishing cable 10 and the sealing of the oil production wellhead 11. The variable frequency control cabinet 13 mainly processes data such as downhole pressure and three-phase electrical parameters collected by downhole sensors, sets reasonable flow pressure and rotational speed adaptive control, and realizes the dynamic balance of production parameters and formation liquid supply.

[0030] The downhole rodless oil production unit includes a sand control screen pipe 1. One end of the sand control screen pipe 1 close to the wellhead is connected to a scale inhibitor 2. A double cup packer 3 is sleeved outside the scale inhibitor 2. The outer wall of the double cup packer 3 fits with the inner wall of the wellbore. Among them, the sand control screen pipe 1, the scale inhibitor 2, and the double cup packer 3 mainly prevent formation sand production, scaling, and gas influence, and provide a good wellbore environment for the linear motor 5 and the plunger pump 6.

[0031] A downhole sensor 4 is installed on the outer wall of the scale inhibitor 2. The downhole sensor 4 is electrically connected to the variable frequency control cabinet 13. Its main function is to collect parameters such as pump suction pressure, pump discharge pressure, pump suction temperature, leakage current, X-axis vibration, Y-axis vibration, and three-phase electrical parameters, and transmit them to the variable frequency control cabinet 13. Then, according to the transmitted data, reasonable flow pressure and rotational speed adaptive control are carried out to realize the dynamic balance of production parameters and formation liquid supply. One end of the scale inhibitor 2 far from the sand control screen pipe 1 is connected to a linear motor 5. The output shaft of the linear motor 5 is connected to a plunger pump 6. The upper end of the plunger pump 6 is connected to the internal fishing cable device. During operation, the linear motor 5 drives the plunger pump 6 to reciprocate up and down through the fishing cable 10 to provide power. During the upstroke, the crude oil in the formation flows into the pump barrel from the liquid inlet. During the downstroke, the crude oil flows from the pump barrel into the oil pipe and is finally lifted to the surface oil pipeline for gathering and transportation.

[0032] The internal fishing cable device includes a fishing cable lower joint 7. The lower end of the fishing cable lower joint 7 is connected to one end of the plunger pump 6 away from the linear motor 5. The upper end of the fishing cable lower joint 7 is communicated with an oil pipe 9, specifically a 2 7 / 8" oil pipe. A fishing cable upper joint 8 that cooperates with the fishing cable lower joint 7 penetrates through the oil pipe 9. The lower end of the fishing cable upper joint 8 penetrates through the fishing cable lower joint 7 and is in contact with it. The upper end of the fishing cable upper joint 8 is connected to a fishing cable 10. The upper end of the fishing cable 10 penetrates through the oil pipe 9 and is connected to a frequency conversion control cabinet 13. The upper end of the oil pipe 9 is communicated with a Christmas tree 11. During operation, the fishing cable 10 is lowered into the oil pipe 9. After being lowered to a predetermined position through the fishing cable upper joint 8, it is accurately docked with the fishing cable lower joint 7. On the one hand, it provides power for the linear motor 5, and on the other hand, it conducts signal transmission, uploading key parameters such as the pump suction pressure, pump discharge pressure, pump suction temperature, leakage current, X-axis vibration, Y-axis vibration, and three-phase electrical parameters to the ground.

[0033] As Figure 2 shown, specifically, the fishing cable lower joint 7 includes a connecting seat 7-7. Above the connecting seat 7-7, there is a fishing outer cylinder 7-5 connected. The fishing outer pipe 7-5 is an oil passage, providing an oil passage for the lifting of the rodless oil production unit. The lower end of the connecting seat 7-7 is connected to the plunger pump 6. Above the connecting seat 7-7, there is a fishing outer cylinder 7-5 fixedly connected. Inside the fishing outer cylinder 7-5, there is a fishing sealing seat 7-6 that matches the inner diameter of the fishing outer cylinder 7-5. The lower end of the fishing sealing seat 7-6 is communicated with a fishing insulating pipe 7-4. The fishing insulating pipe 7-4 uses polytetrafluoroethylene insulating material, with a withstand voltage ≥ DC3500V, a temperature resistance ≥ 200°C, and a corrosion resistance of L80-13cr. There is an annular cavity between the fishing insulating pipe 7-4 and the fishing outer cylinder 7-5. On the inner wall of the fishing insulating pipe 7-4, there is a slide rail type rotary guiding track 7-3 fixedly connected. Among them, the slide rail type rotary guiding track 7-3 adopts a pen tip slide rail structure, and the guiding head is arc-shaped, and it is accurately positioned by welding it inside the rotary joint outer cylinder and changing the direction into the keyway.

[0034] On the connecting seat 7-7, there is a fishing cable pin 7-2. The fishing cable pin 7-2 uses red copper material, with a peak current carrying capacity of 100A and a corrosion resistance of L80-13cr. One end of the fishing cable pin 7-2 away from the slide rail type rotary guiding track 7-3 is connected to a cable lead-out sealing joint 7-1. The free end of the cable lead-out sealing joint 7-1 penetrates through the side wall of the connecting seat 7-7 and is connected to the linear motor 5. This structure can not only connect the cable to the linear motor 5 to provide current for it, but also achieve a sealing effect. The free end of the fishing cable pin 7-2 penetrates through the lower end of the fishing insulating pipe 7-4 and faces the fishing sealing seat 7-6.

[0035] As Figure 3As shown in the figure, the upper joint 8 of the fishing cable includes a weight rod 8-5. The lower end of the weight rod 8-5 penetrates through the fishing insulation pipe 7-4. A fishing cable insulation plug 8-1 is connected to the lower end of the weight rod 8-5. The free end of the fishing cable insulation plug 8-1 is connected to the fishing cable pin 7-2. The fishing cable insulation plug 8-1 adopts a precise guiding docking device, a four-stage self-dissolving high-pressure sealing device, which can meet the good sealing performance under the conditions of 150°C and 35 MPa pressure. A rotary guiding joint 8-2 is arranged on the outer wall of the weight rod 8-5 and is matched with the slide rail type rotary guiding track 7-3. The rotary guiding joint 8-2 fits with the slide rail type rotary guiding track 7-3, mainly used to enter the fishing insulation pipe 7-4 and accurately position with the slide rail type rotary guiding track 7-3. A centralizer 8-3 is sleeved outside the weight rod 8-5. A locking spring seal 8-4 is arranged on the weight rod 8-5. The centralizer 8-3 is located between the rotary guiding joint 8-2 and the locking spring seal 8-4. The locking spring seal 8-4 is located at the connection between the fishing outer cylinder 7-5 and the weight rod 8-5, mainly used to form a locking seal after the lower joint 7 of the fishing cable and the upper joint 8 of the fishing cable are successfully docked, providing a sealed space for the fishing cable plugging assembly. The upper end of the weight rod 8-5 is connected to the fishing cable 10.

[0036] The oil production wellhead 11 is used to hang the 2 7 / 8" tubing 9 and connect the 5 1 / 2" casing to form a wellbore lifting space.

[0037] The oil production method using the rodless oil production device of the fishing cable electric submersible plunger pump of the present invention is as follows:

[0038] S1: Lower and install the rodless oil production unit of the electric submersible plunger pump, from bottom to top: sand control screen pipe 1, scale inhibitor 2, double leather cup packer 3, downhole sensor 4, linear motor 5, plunger pump 6, lower joint 7 of the fishing cable, tubing 9 to the wellhead;

[0039] S2: Lower the fishing cable 10 along the upper end of the tubing 9, so that the upper joint 8 of the fishing cable at the lower end of the fishing cable 10 is accurately docked with the lower joint 7 of the fishing cable, realizing the connection between the fishing cable 10 and the downhole unit;

[0040] S3: Install the Christmas tree 11, conduct system joint debugging, and carry out normal production;

[0041] S4: Through the downhole sensor 4, realize the collection, transmission and intelligent closed-loop control system of rodless oil production parameters, reasonable flow pressure and rotational speed adaptive control, and realize the dynamic balance of production parameters and formation liquid supply.

[0042] Embodiment 1

[0043] The fishing cable electric submersible plunger pump rodless oil production device includes a wellbore. Inside the wellbore, a downhole rodless oil production unit and an internal fishing cable device are successively arranged from bottom to top. The upper ends of the internal fishing cable device are respectively connected to a Christmas tree and a variable frequency control cabinet. Both the Christmas tree and the variable frequency control cabinet are located above the wellbore. A cable sealing device is arranged above the Christmas tree. The downhole rodless oil production unit is electrically connected to the variable frequency control cabinet.

[0044] The oil production method using the fishing cable electric submersible plunger pump rodless oil production device is as follows:

[0045] S1: Lower and install the downhole rodless oil production unit of the electric submersible plunger pump, from bottom to top: sand control screen pipe 1, scale inhibitor 2, double leather cup packer 3, downhole sensor 4, linear motor 5, plunger pump 6, fishing cable lower joint 7, tubing 9 to the wellhead;

[0046] S2: Lower the fishing cable 10 along the upper end of the tubing 9, and precisely dock the fishing cable upper joint 8 at the lower end of the fishing cable 10 with the fishing cable lower joint 7 to realize the connection between the fishing cable 10 and the downhole unit;

[0047] S3: Install the Christmas tree 11, conduct system joint debugging, and carry out normal production;

[0048] S4: Through the downhole sensor 4, realize the acquisition, transmission and intelligent closed-loop control system of rodless oil production parameters, and the adaptive control of reasonable flow pressure and speed to achieve the dynamic balance of production parameters and formation liquid supply.

[0049] Embodiment 2

[0050] The fishing cable electric submersible plunger pump rodless oil production device includes a wellbore. Inside the wellbore, a downhole rodless oil production unit and an internal fishing cable device are successively arranged from bottom to top. The upper ends of the internal fishing cable device are respectively connected to a Christmas tree 11 and a variable frequency control cabinet 13. Both the Christmas tree 11 and the variable frequency control cabinet 13 are located above the wellbore. A cable sealing device 12 is arranged above the Christmas tree 11. The downhole rodless oil production unit is electrically connected to the variable frequency control cabinet 13. During operation, the downhole rodless oil production unit is mainly used to prevent formation sand production, scaling and gas influence, and at the same time carry out oil production work. The internal fishing cable device realizes precise positioning. The oil production wellhead 11 is used to hang the 2 7 / 8" tubing 9 and connect the 5 1 / 2" casing to form a wellbore lifting space. The cable sealing device 12 is used for the gravity suspension of the fishing cable 10 and the sealing of the oil production wellhead 11.

[0051] Embodiment 3

[0052] The cable fishing electric submersible plunger pump rodless oil production device includes a wellbore. Inside the wellbore, a downhole rodless oil production unit and an internal cable fishing device are successively arranged from bottom to top. The upper ends of the internal cable fishing device are respectively connected to a Christmas tree 11 and a variable frequency control cabinet 13. The Christmas tree 11 and the variable frequency control cabinet 13 are both located above the wellbore. A cable sealing device 12 is arranged above the Christmas tree 11. The downhole rodless oil production unit is electrically connected to the variable frequency control cabinet 13.

[0053] The internal cable fishing device includes a fishing cable lower joint 7. The lower end of the fishing cable lower joint 7 is connected to the plunger pump 6. The upper end of the fishing cable lower joint 7 is connected to a tubing 9. Inside the tubing 9, a fishing cable upper joint 8 that cooperates with the fishing cable lower joint 7 is arranged. The upper end of the fishing cable upper joint 8 is connected to a submersible cable 10. The upper end of the submersible cable 10 penetrates through the tubing 9 and is connected to the variable frequency control cabinet 13. The upper end of the tubing 9 is connected to the Christmas tree 11.

[0054] Example 4

[0055] The cable fishing electric submersible plunger pump rodless oil production device includes a wellbore. Inside the wellbore, a downhole rodless oil production unit and an internal cable fishing device are successively arranged from bottom to top. The upper ends of the internal cable fishing device are respectively connected to a Christmas tree 11 and a variable frequency control cabinet 13. The Christmas tree 11 and the variable frequency control cabinet 13 are both located above the wellbore. A cable sealing device 12 is arranged above the Christmas tree 11. The downhole rodless oil production unit is electrically connected to the variable frequency control cabinet 13.

[0056] The internal cable fishing device includes a fishing cable lower joint 7. The lower end of the fishing cable lower joint 7 is connected to the plunger pump 6. The upper end of the fishing cable lower joint 7 is connected to a tubing 9. Inside the tubing 9, a fishing cable upper joint 8 that cooperates with the fishing cable lower joint 7 is arranged. The upper end of the fishing cable upper joint 8 is connected to a submersible cable 10. The upper end of the submersible cable 10 penetrates through the tubing 9 and is connected to the variable frequency control cabinet 13. The upper end of the tubing 9 is connected to the Christmas tree 11.

[0057] The fishing cable lower joint 7 includes a connecting seat 7-7. Above the connecting seat 7-7, a fishing outer cylinder 7-5 is connected. Inside the upper end of the fishing outer cylinder 7-5, a fishing sealing seat 7-6 is arranged. The lower end of the fishing sealing seat 7-6 communicates with a fishing insulating tube 7-4. An annular cavity is arranged between the fishing insulating tube 7-4 and the fishing outer cylinder 7-5. A slide rail type rotary guiding track 7-3 is fixedly connected to the inner wall of the fishing insulating tube 7-4. A fishing cable pin 7-2 is arranged on the connecting seat 7-7. The fishing cable pin 7-2 is connected to a cable lead-out sealing joint 7-1. The free end of the cable lead-out sealing joint 7-1 penetrates through the connecting seat 7-7 and is connected to the linear motor 5. The free end of the fishing cable pin 7-2 penetrates through the lower end of the fishing insulating tube 7-4 and faces the fishing sealing seat 7-6.

Claims

1. A rodless oil production device with a cable electric submersible piston pump, characterized in that: The invention comprises a wellbore, wherein a downhole rodless oil production unit and an internal fishing cable device are arranged in sequence from bottom to top inside the wellbore, and the upper end of the internal fishing cable device is respectively connected to a Christmas tree (11) and a frequency conversion control cabinet (13), and the Christmas tree (11) and the frequency conversion control cabinet (13) are both located above the wellbore, and a cable sealing device (12) is arranged above the Christmas tree (11), and the downhole rodless oil production unit is electrically connected to the frequency conversion control cabinet (13).

2. The cable-casting electric submersible plunger pump rodless oil production device according to claim 1 is characterized in that: The downhole rodless oil production unit comprises a sand screen (1), one end of the sand screen (1) close to the wellhead is connected to a scale preventer (2), a double leather cup packer (3) is sleeved on the outside of the scale preventer (2), the outer wall of the double leather cup packer (3) is in contact with the inner wall of the wellbore, a downhole sensor (4) is installed on the outer wall of the scale preventer (2), the downhole sensor (4) is electrically connected to a frequency conversion control cabinet (13), the end of the scale preventer (2) away from the sand screen (1) is connected to a linear motor (5), the output shaft of the linear motor (5) is connected to a plunger pump (6), and the upper end of the plunger pump (6) is connected to an inner fishing cable device.

3. The cable-casting electric submersible piston pump rodless oil production device according to claim 1 is characterized in that: The inner fishing cable device comprises a fishing cable lower joint (7), the lower end of which is connected to an end of a plunger pump (6) away from a linear motor (5), the upper end of which is connected to an oil pipe (9), the oil pipe (9) having an upper fishing cable joint (8) matching the lower fishing cable joint (7) passing through it, the lower end of which passes through the lower fishing cable joint (7) and contacts it, the upper end of which is connected to a fishing cable (10), the upper end of which passes through the oil pipe (9) and is connected to a frequency conversion control cabinet (13), the upper end of which is connected to a Christmas tree (11).

4. The cable-casting electric submersible piston pump rodless oil production device according to claim 3 is characterized in that: The lower connector (7) of the salvaging cable comprises a connection seat (7-7), the lower end of which is connected to a plunger pump (6), a salvaging outer tube (7-5) is fixedly connected to the upper portion of the connection seat (7-7), a salvaging sealing seat (7-6) matching the inner diameter of the salvaging outer tube (7-5) is provided at the upper portion of the interior of the salvaging outer tube (7-5), a salvaging insulating tube (7-4) is communicated with at the lower end of the salvaging sealing seat (7-6), an annular cavity is provided between the salvaging insulating tube (7-4) and the salvaging outer tube (7-5), and the salvaging insulating tube (7-4) is provided with a sealing seat (7-6) configured to match the inner diameter of the salvaging outer tube (7-5). 4) A slide rail type rotary guide track (7-3) is fixedly connected to the inner wall, a casting cable pin (7-2) is provided on the connection seat (7-7), one end of the casting cable pin (7-2) away from the slide rail type rotary guide track (7-3) is connected to a cable lead-out sealing joint (7-1), a free end of the cable lead-out sealing joint (7-1) penetrates the side wall of the connection seat (7-7) and is connected to the linear motor (5), and a free end of the casting cable pin (7-2) penetrates the lower wall of the casting insulation tube (7-4) and faces the casting sealing seat (7-6).

5. The cable-casting electric submersible plunger pump rodless oil production device according to claim 4 is characterized in that: The slide rail type rotary guide track (7-3) adopts a pen tip slide rail structure, and the guide head is in an arc shape.

6. The cable-casting electric submersible plunger pump rodless oil production device according to claim 4, characterized in that: The fishing cable plug pin (7-2) is made of red copper material, has a peak current carrying capacity of 100A, and is corrosion-resistant to L80-13cr.

7. The cable-casting electric submersible plunger pump rodless oil production device according to claim 4, characterized in that: The salvage insulating pipe (7-4) is made of polytetrafluoroethylene insulation material with a withstand voltage of ≥DC3500V, a temperature of ≥200°C, and a corrosion resistance of L80-13cr.

8. The cable-casting electric submersible piston pump rodless oil production device according to claim 4, characterized in that: The upper connector (8) of the casting and salvaging cable comprises a weighted rod (8-5), the lower end of which passes through the casting and salvaging insulating tube (7-4), the lower end of which is connected to a salvaging cable insulating plug (8-1), the free end of which is connected to a casting and salvaging cable plug pin (7-2), the outer wall of the weighted rod (8-5) is provided with a rotary guide connector (8-2) matched with a slide-type rotary guide track (7-3), the rotary guide connector (8-2) is fitted with the slide-type rotary guide track (7-3), the outer sleeve of the weighted rod (8-5) is provided with a centralizer (8-3), the weighted rod (8-5) is provided with a locking spring seal (8-4), the locking spring seal (8-4) is located at the connection between the casting and salvaging outer tube (7-5) and the weighted rod (8-5), and the upper end of the weighted rod (8-5) is connected to the casting and salvaging cable (10).

9. The cable-casting electric submersible plunger pump rodless oil production device according to claim 8, characterized in that: The centralizer (8-3) is located between the rotary guide joint (8-2) and the locking spring seal (8-4).

10. The method for oil production according to any one of claims 1 to 9, characterized in that: The details are as follows: S1: lowering and installing the electric submersible piston pump rodless oil production unit, from bottom to top: sand screen (1), anti-scaling device (2), double cup packer (3), downhole sensor (4), linear motor (5), piston pump (6), lower connector of the casting and fishing cable (7), and oil pipe (9) to the wellhead; S2: lowering the salvaging cable (10) along the upper end of the oil pipe (9) so that the salvaging cable upper connector (8) at the lower end of the salvaging cable (10) is precisely connected with the salvaging cable lower connector (7), thereby achieving connection between the salvaging cable (10) and the downhole unit; S3: Install the Christmas tree (11), conduct system joint debugging, and carry out normal production; S4: Through the downhole sensor (4), the rodless oil production parameter collection, transmission and intelligent closed-loop control system are realized, and the flow pressure and speed are adaptively controlled to achieve a dynamic balance between the production parameters and the formation fluid supply.

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