Rodless oil extraction device lifted by hydraulic oil cylinder

Abstract

The invention belongs to the technical field of oil exploitation, and particularly discloses a rodless oil extraction device for hydraulic oil cylinder lifting, which comprises a Christmas tree, a valve core, an oil cylinder and an oil well pump, a top wellhead of the Christmas tree is communicated with a ground liquid inlet pipe and a ground liquid outlet pipe respectively, and a right passage of the Christmas tree is communicated with an output liquid pipe; a sleeve and an oil pipe are respectively arranged at a bottom wellhead of the Christmas tree, a valve body is arranged in the oil cylinder, a valve core is positioned between the valve body and an oil well pump piston rod, and an upper positioning ring and a lower positioning ring which are used for pushing the valve core up and down are respectively arranged on the oil well pump piston rod. The problems that in the reversing process of an existing reversing valve, a hydraulic pipeline is prone to connector oil leakage and pipe explosion are solved. The valve body and the valve element of the reversing valve are arranged in the underground oil cylinder, the positioning ring on the piston rod is used for pushing the valve element to achieve reversing, and the service life of a hydraulic pipeline is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of oil production, and in particular to a rodless oil production device lifted by a hydraulic oil cylinder. Background Art

[0002] In the oil production operations of the petroleum industry at home and abroad, there are various types of commonly used oil pumps (oil production pumps), including rod pumps, electric submersible pumps, screw pumps, jet pumps, etc. In many oil wells, the surface pumping unit usually drives the plunger through the sucker rod to make reciprocating movements in the pump barrel, thereby driving oil and water into the plunger and oil pipe to realize the production of oil and water.

[0003] In the hydraulic control system of the oil pump, the reversing valve plays a key role. The reversing valve can change the flow path of the hydraulic oil inside the valve body according to the needs of oil production, and realize selective connection between different oil ports.

[0004] The reversing valves currently on the market are so large that they can only be installed on the ground for reversing operations. Since the reversing valves are on the ground, the hydraulic pipes need to be laid over a longer length to connect the downhole equipment. During the reversing process, the pressure of the hydraulic pipelines will alternate between high and low. If the pressure fluctuates for a long time, the service life of the hydraulic pipelines will be reduced, making it easy for the hydraulic pipelines to leak oil from the joints and burst, and even cause the entire oil production system to fail. Summary of the invention

[0005] The purpose of the present invention is to provide a rodless oil production device lifted by a hydraulic cylinder, so as to solve the problem that during the reversing process of the reversing valve in the current oil production, the pressure of the hydraulic pipeline changes alternately, which reduces the service life of the hydraulic pipeline, and the hydraulic pipeline is prone to joint oil leakage and pipe burst, and even causes the entire oil production system to fail.

[0006] To achieve the above-mentioned purpose, the basic scheme provided by the present invention is: a rodless oil production device lifted by a hydraulic cylinder, comprising an oil tree, a valve core, an oil cylinder and an oil pump, the top wellhead of the oil tree is respectively connected with a ground liquid inlet pipe and a ground liquid outlet pipe, the right passage of the oil tree is connected with a production liquid pipe, a casing and an oil pipe are respectively arranged at the bottom wellhead of the oil tree, the oil pipe is located in the casing, the bottom wellhead of the oil tree is respectively connected with a downhole liquid inlet pipe and a downhole liquid outlet pipe, the downhole liquid inlet pipe, the downhole liquid outlet pipe, the cylinder and the oil pump are all located in the oil pipe, the bottoms of the casing, the oil pipe and the cylinder are all openings, the suction end of the oil pump is located at the opening of the oil pipe, the oil pump is abutted against the oil pipe, the cylinder is located directly above the oil pump, the plunger of the oil pump is connected with the oil cylinder, a limit plate is arranged in the oil cylinder, the piston rod of the oil pump rotates and passes through the limit plate, and a fixing plate is arranged at the end of the piston rod of the oil pump, The oil cylinder is provided with an oil port 1 and an oil port 2, respectively, and the oil port 1 and the oil port 2 are located between the top of the oil cylinder and the fixed plate. A valve body is provided in the oil cylinder, and the valve body is provided with an oil port 3, an oil port 4, an oil port 5 and an oil port 6. The downhole liquid inlet pipe and the downhole liquid outlet pipe are respectively connected with the oil port 5 and the oil port 3, and the oil port 4 and the oil port 6 are respectively connected with the oil port 2 and the oil port 1. The valve body is provided with an annular groove 1, annular groove 2, annular groove 3, annular groove 4 and annular groove 5, respectively. Annular groove five, the annular groove one, annular groove two, annular groove three and annular groove four are connected with oil port three, oil port four, oil port five and oil port six respectively, the annular groove one and annular groove five are connected, the valve core is located between the valve body and the oil pump piston rod, the valve body is provided with a limiting unit for limiting the downward movement of the valve core, the upper and lower ends of the valve body are respectively provided with limiting blocks, and the oil pump piston rod is respectively provided with an upper positioning ring and a lower positioning ring for pushing the valve core up and down.

[0007] The working principle of the present invention is that when the oil pump needs to be lifted for oil extraction, the hydraulic oil first enters the Christmas tree through the ground inlet pipe, then enters the oil port 5 of the valve body through the downhole inlet pipe, and then enters the annular groove 3 from the oil port 5. The internal channel of the valve core is in a connected state with the annular groove 3 and the annular groove 2. The hydraulic oil in the annular groove 3 enters the oil port 4 through the annular groove 2. The hydraulic oil flowing out of the oil port 4 enters the oil cylinder through the pipeline and the oil port 2. As the hydraulic oil continues to enter the oil cylinder, the hydraulic oil will push the fixed plate on the piston rod to move upward, and the piston rod drives the plunger of the oil pump to move upward, thereby realizing the lifting action of the oil pump. At the same time, the hydraulic oil between the fixed plate and the top of the oil cylinder enters the oil port 6 through the oil port 1 and the pipeline, and enters the annular groove 4 from the oil port 6. The internal channel of the valve core is in a connected state with the annular groove 4 and the annular groove 5. The hydraulic oil in the annular groove 4 is discharged through the annular groove 5, the annular groove 1, the oil port 3, the downhole outlet pipe and the ground outlet pipe.

[0008] When the fixed plate on the piston rod moves to the top of the oil cylinder, the lower positioning ring pushes the valve core upward as the piston rod moves upward, and the valve core moves upward under the action of the thrust. When the valve core moves to the limit block above the valve body, the valve core blocks the passage between the annular groove 2 and the annular groove 3, and the hydraulic oil in the annular groove 3 cannot enter the annular groove 2, and then the hydraulic oil cannot enter between the top of the oil cylinder and the fixed plate. Therefore, the piston rod stops moving upward, and the lower positioning ring no longer pushes the valve core. At this time, the annular groove 3 is in a connected state with the annular groove 4, and the annular groove 1 is in a connected state with the annular groove 2. The hydraulic oil enters the annular groove 3 from the oil port 5, and then passes through the internal passage of the valve core, through the annular groove 4, the oil port 6 and the oil port 1 into the oil cylinder. The hydraulic oil pushes the fixed plate on the piston rod to move downward, and the piston rod drives the plunger of the oil pump to move downward, so that the oil sucked by the oil pump enters the oil pipe through the oil discharge port on the oil cylinder. At the same time, the hydraulic oil between the fixed plate and the bottom of the oil cylinder enters the oil port four through the oil port two and the pipeline, and enters the annular groove two from the oil port four. The internal channel of the valve core is connected with the annular groove two and the annular groove one. The hydraulic oil in the annular groove two is discharged through the annular groove one, the oil port three, the downhole liquid outlet pipe and the ground liquid outlet pipe.

[0009] When the fixed plate on the piston rod approaches the limit plate, the upper positioning ring moves with the movement of the piston rod and pushes the valve core downward. When the valve core moves to the limit block below the valve body, the valve core blocks the passage between the annular groove four and the annular groove three, and the hydraulic oil in the annular groove three cannot enter the annular groove four, and then the hydraulic oil cannot enter between the limit plate and the fixed plate. Therefore, the piston rod stops moving downward, and the upper positioning ring no longer pushes the valve core. The valve body, valve core, upper positioning ring and lower positioning ring work in this cycle to achieve the reversal of the hydraulic oil.

[0010] The beneficial effects of the present invention are as follows: the valve body and valve core of the reversing valve are arranged in the downhole oil cylinder, and the positioning ring on the piston rod is used to push the valve core to achieve reversal, thereby reducing the excessive length of the hydraulic pipeline. At the same time, the hydraulic pipeline is arranged in the oil pipe, which increases the service life of the hydraulic pipeline and reduces the risk of system failure caused by hydraulic pipeline problems.

[0011] Option 2, which is a preferred option of the basic option, the limiting unit includes a steel ball, the valve body is provided with a groove, the groove is provided with a spring, the spring is connected to the steel ball, and the valve core is provided with a limiting groove for placing the steel ball; when the positioning ring on the piston rod pushes the valve core, the valve core overcomes the elastic force of the spring to make the steel ball disengage from the limiting groove, thereby realizing the movement of the valve core; when the positioning ring no longer pushes the valve core, an upward friction force is generated between the valve core and the steel ball to prevent the valve core from falling downward due to its own gravity.

[0012] Option three is the preferred basic option. Flow meters are provided on the surface inlet pipe and the output pipe. Since the displacement ratio of the inlet liquid to the output liquid is the ratio of the area of ​​the oil pump plunger to the area of ​​the oil cylinder piston, it can be judged whether there is a dry pumping phenomenon due to insufficient liquid supply based on the displacement of the inlet liquid and the output liquid. The flow meter can measure the flow of the hydraulic oil entering and outputting in real time, so as to facilitate the operator to increase or decrease the inlet liquid, thereby obtaining maximum production and minimum energy consumption.

[0013] Option 4 is a preferred option of the basic option. Ball bearings are rotatably connected to both sides of the fixed plate. The arrangement of the balls reduces the friction between the fixed plate and the inner wall of the cylinder, making the piston rod move more smoothly.

[0014] Option 5, which is the preferred option of the basic option, is that the top wellhead of the Christmas tree is provided with a sealing assembly for sealing the ground liquid inlet pipe and the ground liquid outlet pipe; they are connected through a wellhead sealer to improve the sealing performance of the connection between the Christmas tree wellhead and the ground pipeline to prevent liquid leakage.

[0015] Option 6, which is a preferred embodiment of Option 5, the sealing assembly includes a shell, a steel ring, a pressure pad and a sealing sleeve. The top wellhead surface of the Christmas tree and the bottom of the shell are provided with an annular groove for embedding the steel ring. A concave groove is provided in the shell. The pressure pad and the sealing sleeve are located in the concave groove. The pressure pad is located directly above the sealing sleeve. An upper cover is bolted to the shell. Two through holes for penetrating a ground liquid inlet pipe and a ground liquid outlet pipe are provided in the shell, the pressure pad, the sealing sleeve and the upper cover. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of a rodless oil production device lifted by a hydraulic cylinder according to the present invention; Figure 2 It is a structural schematic diagram of a rodless oil production device lifted by a hydraulic cylinder according to the present invention when the piston rod moves upward; Figure 3 for Figure 2 The enlarged view of point A in the middle; Figure 4 It is a structural schematic diagram of a rodless oil extraction device lifted by a hydraulic cylinder according to the present invention when an upper positioning ring pushes a valve core downward; Figure 5 for Figure 4 The enlarged view of point B in the middle; Figure 6 The present invention is a structural schematic diagram of a sealing assembly in a rodless oil production device lifted by a hydraulic cylinder. DETAILED DESCRIPTION

[0017] The present invention is further described in detail below through specific embodiments: The reference numerals in the drawings of the specification include: 1 Christmas tree, 101 surface liquid inlet pipe, 102 surface liquid outlet pipe, 103 production liquid pipe, 104 downhole liquid inlet pipe, 105 downhole liquid outlet pipe, 106 flow meter, 2 casing, 3 oil pipe, 4 oil cylinder, 401 limit plate, 402 oil port 1, 403 oil port 2, 5 oil pump, 501 plunger, 502 piston rod, 503 fixing plate, 504 upper positioning ring, 505 Lower locating ring, 506 ball, 6 valve body, 601 valve core, 602 limit block, 603 oil port three, 604 oil port four, 605 oil port five, 606 oil port six, 607 steel ball, 608 spring, 609 annular groove one, 610 annular groove two, 611 annular groove three, 612 annular groove four, 613 annular groove five, 701 shell, 702 steel ring, 703 pressure pad, 704 sealing sleeve, 705 upper cover.

[0018] like Figures 1 to 6 As shown: a rodless oil production device lifted by a hydraulic cylinder, comprising a Christmas tree 1, a valve core 601, a cylinder 4 and a pump 5, the top wellhead of the Christmas tree 1 is connected with a ground liquid inlet pipe 101 and a ground liquid outlet pipe 102, the right passage of the Christmas tree 1 is connected with a production liquid pipe 103, flow meters 106 are provided on the ground liquid inlet pipe 101 and the production liquid pipe 103, the top wellhead of the Christmas tree 1 is provided with a sealing assembly for sealing the ground liquid inlet pipe 101 and the ground liquid outlet pipe 102, the sealing assembly comprises a housing 701, a steel ring 702 , a pressure pad 703 and a sealing sleeve 704, the top wellhead surface of the Christmas tree 1 and the bottom of the shell 701 are provided with an annular groove for embedding the steel ring 702, a concave groove is opened in the shell 701, the pressure pad 703 and the sealing sleeve 704 are located in the concave groove, the pressure pad 703 is located directly above the sealing sleeve 704, an upper cover 705 is bolted to the shell 701, and two through holes for penetrating the ground liquid inlet pipe 101 and the ground liquid outlet pipe 102 are opened on the shell 701, the pressure pad 703, the sealing sleeve 704 and the upper cover 705.

[0019] The bottom wellhead of the Christmas tree 1 is respectively fixedly connected with a casing 2 and an oil pipe 3, the oil pipe 3 is located in the casing 2, and the bottom wellhead of the Christmas tree 1 is respectively connected with a downhole liquid inlet pipe 104 and a downhole liquid outlet pipe 105, the downhole liquid inlet pipe 104, the downhole liquid outlet pipe 105, the oil cylinder 4 and the oil pump 5 are all located in the oil pipe 3, the downhole liquid inlet pipe 104 and the downhole liquid outlet pipe 105 are hydraulic pipes made of high temperature resistant and corrosion resistant materials, the bottoms of the casing 2, the oil pipe 3 and the oil cylinder 4 are all open, and the pump 5 The suction end of the oil pump 5 is located at the opening of the oil pipe 3, and the outer wall of the suction end of the oil pump 5 is against the inner wall of the opening of the oil pipe 3. The oil cylinder 4 is located directly above the oil pump 5. The plunger 501 of the oil pump 5 is connected to the oil cylinder 4. A limit plate 401 is fixedly connected inside the oil cylinder 4. The piston rod 502 of the oil pump 5 rotates and passes through the limit plate 401. The end of the piston rod 502 of the oil pump 5 is fixedly connected to a fixed plate 503, and balls 506 are rotatably connected to both sides of the fixed plate 503.

[0020] The oil cylinder 4 is provided with an oil port 1 402 and an oil port 2 403, respectively. The oil port 1 402 and the oil port 2 403 are located between the top of the oil cylinder 4 and the fixed plate 503. A valve body 6 is embedded in the oil cylinder 4. The valve body 6 is provided with an oil port 3 603, an oil port 4 604, an oil port 5 605 and an oil port 606. The downhole liquid inlet pipe 104 and the downhole liquid outlet pipe 105 are respectively connected with the hydraulic pipe between the oil port 5 605 and the oil port 3 603 through a hydraulic pipe rotary joint. The oil port 4 604 and the oil port 6 606 are respectively connected with the oil port 2 403 and the oil port 1 402. The valve body 6 is provided with an annular groove 1 609, an annular groove 2 610, an annular groove 3 611, annular groove 4 612 and annular groove 5 613, and the annular groove 1 609, the annular groove 2 610 , annular groove three 611 and annular groove four 612 are connected with oil port three 603, oil port four 604, oil port five 605 and oil port six 606 respectively, annular groove one 609 and annular groove five 613 are connected, the valve core 601 is located between the valve body 6 and the piston rod 502 of the oil pump 5, the valve body 6 is provided with a limiting unit for limiting the downward movement of the valve core 601, the limiting unit includes a steel ball 607, the valve body 6 is provided with a groove, a spring 608 is provided in the groove, the spring 608 is connected to the steel ball 607, the valve core 601 is provided with a limiting groove for placing the steel ball 607, the upper and lower ends of the valve body 6 are respectively provided with limiting blocks 602, and the piston rod 502 of the oil pump 5 is respectively provided with an upper positioning ring 504 and a lower positioning ring 505 for pushing the valve core 601 up and down.

[0021] The implementation method of this embodiment is as follows: when it is necessary to lift the oil pump 5 for oil production, the hydraulic oil first enters the Christmas tree 1 through the ground liquid inlet pipe 101, then enters the oil port 5 605 of the valve body 6 through the downhole liquid inlet pipe 104, and then enters the annular groove 3 611 from the oil port 5 605. The internal channel of the valve core 601 is in a connected state with the annular groove 3 611 and the annular groove 2 610. The hydraulic oil in the annular groove 3 611 enters the oil port 4 604 through the annular groove 2 610. The hydraulic oil flowing out of the oil port 4 604 enters the oil cylinder 4 through the pipeline and the oil port 2 403. As the hydraulic oil continues to enter the oil cylinder 4, the hydraulic oil will push the fixed plate 503 on the piston rod 502 to move upward, and the piston rod 502 drives the plunger 501 of the oil pump 5 to move upward, thereby realizing the lifting action of the oil pump 5. At the same time, the hydraulic oil between the fixed plate 503 and the top of the oil cylinder 4 enters the oil port 6 606 through the oil port 1 402 and the pipeline, and enters the annular groove 4 612 from the oil port 606. The internal channel of the valve core 601 is connected with the annular groove 4 612 and the annular groove 5 613. The hydraulic oil in the annular groove 4 612 is discharged through the annular groove 5 613, the annular groove 1 609, the oil port 3 603, the downhole liquid outlet pipe 105 and the ground liquid outlet pipe 102.

[0022] When the fixing plate 503 on the piston rod 502 moves to the top of the oil cylinder 4, the lower positioning ring 505 that moves upward with the piston rod 502 pushes the valve core 601 upward. Under the action of the thrust, the steel ball 607 below the valve body 6 of the valve core 601 disengages from the limiting groove, the spring 608 is compressed, the steel ball 607 enters the groove, and the valve core 601 moves upward. When the valve core 601 moves to the limiting block 602 above the valve body 6, the valve core 601 blocks the passage between the annular groove 2 610 and the annular groove 3 611, and the hydraulic oil in the annular groove 3 611 cannot enter the annular groove 2 610, and then the hydraulic oil cannot enter between the top of the oil cylinder 4 and the fixing plate 503. Therefore, the piston rod 502 stops moving upward, and the lower positioning ring 505 no longer pushes the valve core 601. Under the push of the spring 608, the steel ball 607 above the valve body 6 is re-stuck in the limiting groove. At this time, annular groove three 611 is in a connected state with annular groove four 612, and annular groove one 609 is in a connected state with annular groove two 610. The hydraulic oil enters annular groove three 611 from oil port five 605, and then passes through the internal passage of valve core 601, annular groove four 612, oil port six 606 and oil port one 402 to enter oil cylinder 4. The hydraulic oil pushes the fixed plate 503 on the piston rod 502 to move downward, and the piston rod 502 drives the plunger 501 of the oil pump 5 to move downward, so that the oil sucked by the oil pump 5 enters the oil pipe 3 through the oil discharge port on the oil cylinder 4. At the same time, the hydraulic oil between the fixed plate 503 and the bottom of the oil cylinder 4 enters the oil port four 604 through the oil port two 403 and the pipeline, and enters the annular groove two 610 from the oil port four 604. The internal channel of the valve core 601 is connected with the annular groove two 610 and the annular groove one 609. The hydraulic oil in the annular groove two 610 is discharged through the annular groove one 609, the oil port three 603, the downhole liquid outlet pipe 105 and the ground liquid outlet pipe 102.

[0023] When the fixed plate 503 on the piston rod 502 approaches the limit plate 401, the upper positioning ring 504 that moves with the piston rod 502 pushes the valve core 601 downward. Under the action of the thrust, the steel ball 607 above the valve body 6 of the valve core 601 disengages from the limit groove, the spring 608 is compressed, the steel ball 607 enters the groove, and the valve core 601 moves downward. When the valve core 601 moves to the limit block 602 below the valve body 6, the valve core 601 blocks the passage between the annular groove four 612 and the annular groove three 611, and the hydraulic oil in the annular groove three 611 cannot enter the annular groove four 612, and then the hydraulic oil cannot enter between the limit plate 401 and the fixed plate 503. Therefore, the piston rod 502 stops moving downward, and the upper positioning ring 504 no longer pushes the valve core 601. Under the push of the spring 608, the steel ball 607 below the valve body 6 is re-stuck in the limit groove. In the above process, the valve body 6, the valve core 601, the upper positioning ring 504 and the lower positioning ring 505 work in a cycle to achieve the reversal of the hydraulic oil.

[0024] The above is only an embodiment of the present invention, and the common knowledge such as the known specific structure and characteristics in the scheme is not described in detail here. It should be pointed out that for those skilled in the art, several deformations and improvements can be made without departing from the structure of the present invention, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A rodless oil extraction device lifted by a hydraulic cylinder, characterized in that: The invention comprises a Christmas tree (1), a valve core (601), an oil cylinder (4) and an oil pump (5). The top wellhead of the Christmas tree (1) is respectively connected to a surface liquid inlet pipe (101) and a surface liquid outlet pipe (102). The right passage of the Christmas tree (1) is connected to a production liquid pipe (103). The bottom wellhead of the Christmas tree (1) is respectively provided with a casing (2) and an oil pipe (3). The oil pipe (3) is located in the casing (2). The bottom wellhead of the Christmas tree (1) is respectively connected to a downhole liquid inlet pipe (104) and a downhole liquid outlet pipe (105). The downhole liquid inlet pipe (104), the downhole liquid outlet pipe (105), the oil cylinder (4) and the oil pump (5) are all located in the oil pipe (3). The casing (2), the oil pipe ( The bottoms of the oil pipe (3) and the oil cylinder (4) are both open, the suction end of the oil pump (5) is located at the opening of the oil pipe (3), the oil pump (5) and the oil pipe (3) are butted against each other, the oil cylinder (4) is located directly above the oil pump (5), the plunger (501) of the oil pump (5) is connected to the oil cylinder (4), a limit plate (401) is provided in the oil cylinder (4), the piston rod (502) of the oil pump (5) rotates and passes through the limit plate (401), a fixing plate (503) is provided at the end of the piston rod (502) of the oil pump (5), and the oil cylinder (4) is respectively opened with an oil port 1 (402) and an oil port 2 (403), the oil port 1 (402) and the oil port 2 (403) are located at the top of the oil cylinder (4). The oil cylinder (4) is provided with a valve body (6) between the end and the fixed plate (503). The valve body (6) is provided with oil port 3 (603), oil port 4 (604), oil port 5 (605) and oil port 6 (606). The downhole liquid inlet pipe (104) and the downhole liquid outlet pipe (105) are respectively connected with oil port 5 (605) and oil port 3 (603). The oil port 4 (604) and oil port 6 (606) are respectively connected with oil port 2 (403) and oil port 1 (402). The valve body (6) is provided with an annular groove 1 (609), an annular groove 2 (610), an annular groove 3 (611), an annular groove 4 (612) and an annular groove 5 (613). The annular groove 1 (609), Annular groove 2 (610), annular groove 3 (611) and annular groove 4 (612) are respectively connected to oil port 3 (603), oil port 4 (604), oil port 5 (605) and oil port 6 (606); annular groove 1 (609) and annular groove 5 (613) are connected; the valve core (601) is located between the valve body (6) and the piston rod (502) of the oil pump (5); a limiting unit for limiting the downward movement of the valve core (601) is provided on the valve body (6); limiting blocks (602) are respectively provided at the upper and lower ends of the valve body (6); an upper positioning ring (504) and a lower positioning ring (505) for pushing the valve core (601) up and down are respectively provided on the piston rod (502) of the oil pump (5).

2. A rodless oil extraction device lifted by a hydraulic cylinder according to claim 1, characterized in that: The limiting unit comprises a steel ball (607), the valve body (6) is provided with a groove, a spring (608) is provided in the groove, the spring (608) is connected to the steel ball (607), and the valve core (601) is provided with a limiting groove for accommodating the steel ball (607).

3. The rodless oil extraction device lifted by a hydraulic cylinder according to claim 1, characterized in that: The surface liquid inlet pipe (101) and the output liquid pipe (103) are both provided with flow meters (106).

4. The rodless oil extraction device lifted by a hydraulic cylinder according to claim 1, characterized in that: Balls (506) are rotatably connected to both sides of the fixing plate (503).

5. The rodless oil extraction device lifted by a hydraulic cylinder according to claim 1, characterized in that: The top wellhead of the Christmas tree (1) is provided with a sealing assembly for sealing a surface liquid inlet pipe (101) and a surface liquid outlet pipe (102).

6. A rodless oil extraction device lifted by a hydraulic cylinder according to claim 5, characterized in that: The sealing assembly comprises a shell (701), a steel ring (702), a pressure pad (703) and a sealing sleeve (704); the top wellhead surface of the Christmas tree (1) and the bottom of the shell (701) are provided with an annular groove for embedding the steel ring (702); a concave groove is provided in the shell (701); the pressure pad (703) and the sealing sleeve (704) are located in the concave groove; the pressure pad (703) is located directly above the sealing sleeve (704); an upper cover (705) is bolted to the shell (701); and two through holes for penetrating a surface liquid inlet pipe (101) and a surface liquid outlet pipe (102) are provided in the shell (701), the pressure pad (703), the sealing sleeve (704) and the upper cover (705).

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