Immovable string rod type pump oil extraction string and working method

Abstract

The invention discloses an immovable string rod type pump oil extraction string and a working method. An oil well pump is arranged in an oil pipe, the oil well pump is provided with a pump cylinder, a plunger is arranged in the pump cylinder, and the top of the plunger is connected with a sucker rod; the packer is arranged below the oil well pump in the oil pipe, a tie-back locking and sealing device is connected to the inner wall of the packer in an inserted mode, and the top of the tie-back locking and sealing device is connected with the oil well pump; the tie-back locking and sealing device comprises a sealing cylinder, and the outer side of the sealing cylinder is sleeved with a seal. The bottom of the tie-back locking and sealing device is connected with a locking claw; the packer comprises a hollow barrel, clamping teeth are arranged on the outer side of the top of the hollow barrel, a sealing rubber barrel is arranged on the outer side of the hollow barrel in a sleeving mode, and a sealing seat and a supporting clamping seat are arranged on the inner side of the hollow barrel. According to the method, the original well oil pipe can be continuously used in the process that flowing oil production is converted into rod pump oil production, the service life of the oil pipe is prolonged, the time and economic cost of well repair operation are reduced, and the production time and efficiency of an oil well are overall improved.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas exploration and development technology, specifically relating to a stationary tubing rod pump oil production tubing string and its working method. Background Technology

[0002] In the early stages of oilfield development, the initial formation pressure is high, enabling oil wells to achieve spontaneous flow production. However, as formation energy is gradually depleted, spontaneous flow production can no longer meet the production demands, necessitating artificial lift production to maintain well output. Rod pump production, with its advantages of convenient pump inspection and deep insertion depth, has become a widely used artificial lift production method. During the transition from spontaneous flow to rod pump production, well workover operations are often required to remove the original tubing used for spontaneous flow production before installing new tubing and the corresponding rod pump string. This process presents several problems: firstly, it increases the operation time and costs associated with well workover; secondly, the original tubing removed during the workover requires repair before reuse, increasing economic costs and shortening the tubing's lifespan.

[0003] Furthermore, after oil is produced by a self-flowing rotary rod pump, the conventional rod pumps that are lowered into the well have the following shortcomings in practical applications due to the characteristics of the pump body structure: First, during the pump's entry into the well, it is often necessary to raise and lower the pump multiple times to accurately set it to the locking point, which poses a risk of failure of some seals; Second, after the pump is lowered into the well, its working position in the well is relatively fixed, which to some extent restricts the pump's working environment. Moreover, when the working position of the pump needs to be adjusted according to changes in production conditions, it is unavoidable to work on the entire tubing string structure, including the tubing, which increases the overall operation cycle.

[0004] Patent publication number CN 202338294 U, entitled "Intelligent Completion String Integrating Flowing and Mechanical Production," discloses an intelligent method for oil production using sliding sleeve stratified production in conjunction with a rod pump. However, this method relies on a surface control system to open or close the nozzles on the sliding sleeves corresponding to each oil and gas layer in the wellbore to achieve stratified and combined oil production. Without moving the production tubing, opening the nozzles on the sliding sleeves corresponding to each oil and gas layer allows for direct fracturing and / or acidizing operations in each layer. The key is the surface control of the sliding sleeve switches for stratified oil production / acidizing; the pump is an auxiliary device with a fixed position within the tubing. However, this patent application does not allow for adjusting the pump's operating position by adjusting the packer setting position. Summary of the Invention

[0005] In order to overcome the problems existing in the prior art, the purpose of this invention is to provide a rod pump oil production tubing string and working method with a fixed tubing string, which can continue to use the original well tubing during the process of switching from self-flowing oil production to rod pump oil production. This not only increases the service life of the tubing, but also reduces the time and economic cost of well workover operations, thereby improving the overall production time and efficiency of the oil well.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A stationary tubing string for rod-type pump oil production includes: tubing and a packer. An oil pump is installed inside the tubing, the oil pump having a pump barrel containing a plunger, and a sucker rod connected to the top of the plunger. The packer is located below the oil pump inside the tubing, and a reconnection locking seal device is inserted into the inner wall of the packer. The top of the reconnection locking seal device is connected to the oil pump. The reconnection locking seal device includes a sealing cylinder, with a seal fitted on the outer side of the sealing cylinder. A locking claw is connected to the bottom of the reconnection locking seal device. The packer includes a hollow cylinder, with a locking tooth on the outer top of the hollow cylinder, a sealing rubber sleeve fitted on the outer side of the hollow cylinder, and a sealing seat and a support seat on the inner side of the hollow cylinder.

[0008] Optionally, the seal includes a non-metallic seal and a metallic seal, with the non-metallic seal disposed above the metallic seal.

[0009] Optionally, the non-metallic seal includes a first non-metallic seal and a second non-metallic seal, and the first non-metallic seal, the second non-metallic seal, and the metal seal are sequentially fitted on the outer side of the sealing cylinder from top to bottom.

[0010] Optionally, the metal seal is a steel ring, and the non-metal seal is a rubber ring.

[0011] Optionally, the sealing seat includes a non-metallic sealing seat and a metallic sealing seat, wherein the non-metallic sealing seat is disposed above the metallic sealing seat.

[0012] Optionally, the non-metallic sealing seat includes a non-metallic sealing seat and a second non-metallic sealing seat, and the inner side of the hollow cylinder is sequentially fitted with a sealing rubber sleeve, a first non-metallic sealing seat and a second non-metallic sealing seat from top to bottom.

[0013] Optionally, the packer is a removable packer.

[0014] Optionally, the lowermost end of the pump barrel is provided with an embedded threaded female thread.

[0015] The method for operating a stationary tubing rod pump oil production tubing string includes the following steps:

[0016] The packer is lowered into the corresponding position designed inside the tubing. By applying pressure, the jaws at the top of the packer open outwards, and at the same time, the sealing sleeve expands under pressure, thus setting the packer.

[0017] The combination of the oil pump and the return locking seal device, when the return locking seal device comes into contact with the packer, the locking claw retracts under the action of gravity and locks in the lower support seat of the packer;

[0018] Adjust the position of the plunger connected to the lower end of the sucker rod in the pump barrel by raising or lowering the sucker rod.

[0019] Optionally, when the fluid level in the wellbore changes, the packer can be unsealed first, while keeping the tubing in the same condition, before the pump and sucker rod can be removed.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] This invention enables the continued use of the original well tubing during the transition from self-flowing oil production to rod pump oil production. This not only increases the service life of the tubing but also reduces the time and economic cost of well workover operations, thereby improving the overall production time and efficiency of the oil well.

[0022] This invention can avoid the need for well workover operations during the transition from flowing oil production to rod pump oil production, thereby improving the production time and efficiency of oil wells. Furthermore, it can adjust the working position of the pump by adjusting the packer setting position according to subsequent actual production needs, thus providing technical support for rod pump oil production.

[0023] Furthermore, another objective of this invention is to provide an oil extraction method that can reduce the risk of partial seal failure during pump entry into the well, and the working position of the pump can be adjusted according to production needs after entry into the well, effectively reducing operational procedures and providing technical support for the conversion of self-flowing oil extraction to rod pump oil extraction. Attached Figure Description

[0024] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely schematic to aid in understanding the invention and do not specifically limit the shapes and proportions of the components. In the drawings:

[0025] Figure 1 A schematic diagram of the overall structure of the rod pump oil production tubing string;

[0026] Figure 2 This is a schematic diagram of the reconnection locking sealing device.

[0027] Figure 3 Schematic diagram of packer structure.

[0028] In the diagram: 1. Oil pipe; 2. Sucker rod; 3. Oil pump; 4. Plunger; 5. Pump barrel; 6. Reconnection locking seal device; 7. Packer; 8. First non-metallic seal; 9. Second non-metallic seal; 10. Metallic seal; 11. Locking claw; 12. Clamping tooth; 13. Sealing sleeve; 14. First non-metallic seal seat; 15. Second non-metallic seal seat; 16. Metallic seal seat; 17. Support bracket. Detailed Implementation

[0029] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0030] It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0032] The present invention will now be described in detail with reference to the accompanying drawings.

[0033] like Figure 1As shown, the present invention discloses a stationary tubing string for rod-type pump oil production, characterized in that it comprises: tubing 1 and packer 7; an oil pump 3 is disposed inside the tubing 1; the oil pump 3 has a pump barrel 5; a plunger 4 is disposed inside the pump barrel 5; a sucker rod 2 is connected to the top of the plunger 4; the packer 7 is disposed below the oil pump 3 inside the tubing 1; a reconnection locking seal device 6 is inserted and connected to the inner wall of the packer 7; the top of the reconnection locking seal device 6 is connected to the oil pump 3; the reconnection locking seal device 6 includes a sealing cylinder; a seal is sleeved on the outer side of the sealing cylinder; a locking claw 11 is connected to the bottom of the reconnection locking seal device 6; the packer 7 includes a hollow cylinder; a locking tooth 12 is provided on the outer side of the top of the hollow cylinder; a sealing rubber sleeve 13 is sleeved on the outer side of the hollow cylinder; and a sealing seat and a support seat 17 are disposed on the inner side of the hollow cylinder.

[0034] The seal includes a non-metallic seal and a metallic seal 10. The non-metallic seal includes a first non-metallic seal 8 and a second non-metallic seal 9. The first non-metallic seal 8, the second non-metallic seal 9 and the metallic seal 10 are sequentially fitted on the outer side of the sealing cylinder from top to bottom.

[0035] The sealing seat includes a non-metallic sealing seat and a metallic sealing seat 16. The non-metallic sealing seat includes a non-metallic sealing seat 14 and a second non-metallic sealing seat 15. The inner side of the hollow cylinder is fitted with a sealing rubber sleeve 13, a first non-metallic sealing seat 14 and a second non-metallic sealing seat 15 from top to bottom.

[0036] Optionally, the metal seal 10 is a steel ring, and the non-metallic seal is a rubber ring. The packer 7 is a removable packer.

[0037] Specifically, the oil pump 3 in this invention has an embedded threaded female thread at the lowest end of the pump barrel 5. The working principle of the oil pump 3 is that the surface pumping unit drives the sucker rod 2 and the plunger 4 in the oil pump 3 connected to the lower end of the sucker rod 2 to move up and down in the pump barrel 5 under the action of mechanical reciprocating motion. When the plunger 4 moves upward, the volume of the lower pump chamber below the plunger 4 increases and the pressure decreases. The inlet valve opens under the action of the pressure difference between the upper and lower parts, and crude oil enters the lower chamber. At the same time, the outlet valve closes under the action of the pressure difference between the upper and lower parts, and the crude oil in the upper pump chamber above the plunger 4 is lifted and discharged to the ground along the oil pipe 1. When the plunger 4 moves downward, the plunger 4 compresses the crude oil between the inlet valve and the outlet valve, closes the inlet valve, and opens the outlet valve. The crude oil in the lower pump chamber enters the upper pump chamber through the cavity of the outlet valve and the plunger 4.

[0038] The reconnection locking sealing device 6 ensures that setting can be completed within the packer 7. The interior of the cylinder serves as a fluid flow channel, and from top to bottom, the outer surface of the cylinder is provided with a male thread, three sealing structures, and a locking claw 11. The male thread matches the female thread at the bottom of the pump barrel 5 of the oil pump 3. The three sealing structures include two non-metallic seals 10 and one metallic seal 10. The non-metallic seal 10 consists of a temperature-resistant, pressure-resistant, and corrosion-resistant composite material sealing ring nested on the outer surface of the cylinder, while the metallic seal 10 consists of a temperature-resistant, pressure-resistant, and corrosion-resistant copper alloy material nested on the outer surface of the cylinder. The locking claw 11 is located at the bottom of the reconnection locking sealing device 6, and the opening degree of the locking claw 11 can be controlled by the force applied.

[0039] The packer 7 can be one of the conventional packers 7, and its main structure, from top to bottom, includes a jaw 12, a sealing sleeve 13, two non-metallic sealing seats, a metallic sealing seat, and a support seat. Preferably, the size of the packer 7 in this invention should be designed according to the size of the tubing 1 corresponding to the designed well depth to ensure the normal insertion and setting of the packer 7 in the tubing 1.

[0040] The present invention provides a method for operating a stationary tubing rod pump oil production tubing string, comprising the following steps:

[0041] S1: Install packer 7. When the oil well is switched from self-flowing oil production to rod pump oil production, before installing the oil pump 3, the packer 7 in the tubing 1 must be installed into the tubing 1 using the coiled tubing 1.

[0042] S2: Packer 7 Sealing Verification. After the packer 7 is lowered to the designed setting position, refer to the testing procedure for packer 7 in separate production and injection wells (SY / T 5734—1995). Inject clean water into the coiled tubing 1 from the wellhead to pressurize the packer 7 to the design pressure P1, causing the jaws 12 at the upper end of the packer 7 to open outwards and support it against the inner wall of the tubing 1, thus achieving the setting of the packer 7. After the packer 7 is set in the tubing 1, inject clean water into the annulus between the casing and the coiled tubing 1 from the wellhead and pressurize it to the design pressure P2 to verify the setting of the packer 7. When the pressure drop is less than 0.5 MPa after 15 minutes, the packer 7 is considered to have passed the setting test. Finally, pull out the tubing 1.

[0043] S3: Assemble the rod pump and locking seal device. First, assemble all components of the oil pump 3 on the ground. After the pump is assembled, connect the upper part of the pump to the sucker rod 2, and connect the locking seal device 6 to the lower end of the pump by means of a threaded connection.

[0044] S4: Lower the rod pump production tubing string 1. Lower the assembled pump 3 components and the reconnection locking seal device 6 from the wellhead at a certain speed V1. When the pump is close to the packer 7 inside the tubing 1, reduce the lowering speed of the pump 3 and the reconnection locking seal device 6 to V2. When the reconnection locking seal device 6 connected to the rod pump comes into contact with the packer 7 inside the tubing 1, the locking claw 11 at the lower end of the reconnection locking seal device 6 will retract under the weight of the pump 3 and the upper sucker rod 2, causing the locking claw 11 to lock into the lower part of the packer 7 support bracket. Meanwhile, the metal and non-metal seals 10 on the upper part of the reconnection locking seal device 6 will fit against the non-metallic and metal seal seats inside the packer 7, thus completing the fixation of the pump 3 and the reconnection locking seal device 6.

[0045] S5: Verification of the sealing performance of the rod pump production tubing string 1. After all components of the rod pump production tubing string 1 structure are installed in the well, clean water is injected into the tubing 1 from the wellhead. When the wellhead pressure rises to the design pressure P3, the injection is stopped. The two composite material sealing rings on the locking sealing device, which act as non-metallic seals 10, will expand under pressure, achieving the purpose of sealing the gap between the locking sealing device 6 and the packer 7. After 15 minutes, the wellhead pressure drop is less than 0.5 MPa, which is acceptable.

[0046] S6: Adjustment of plunger 4 position. After the entire tubing has passed the sealing test, adjust the position of the plunger 4 connected to the lower end of the sucker rod 2 in the pump barrel 5 by raising or lowering the sucker rod 2. This ensures that during the production process, when the sucker rod 2 drives the plunger 4 to move up and down in the pump barrel 5, the plunger 4 will not collide with the fixed ball bearing in the pump barrel 5 or the bottom of the pump barrel 5 due to the elastic deformation of the sucker rod 2 connected to the upper end.

[0047] Example

[0048] The present invention provides a stationary tubing string for rod pump oil production, used when switching from flowing oil production to rod pump oil production in an oil well:

[0049] First, use coiled tubing to lower the packer 7 into the designed position inside tubing 1.

[0050] Subsequently, following step S2 in the above-mentioned working method of rod pump oil production tubing with stationary tubing, the packer 7 was pressure-set and its sealing was verified.

[0051] During the pressurization process, the jaws 12 at the upper end of the packer 7 open outwards and support the inner wall of the oil pipe. At the same time, the sealing sleeve 13 expands under pressure, thus setting the packer.

[0052] The pumping unit 3 and the reconnection locking seal device 6, which are assembled on the ground, are lowered into the wellhead. When the pumping unit 3 and the reconnection locking seal device 6 are lowered to a position close to the packer 7, the lowering speed of the pumping unit 3 and the reconnection locking seal device 6 is reduced. When the reconnection locking seal device 6 connected to the pumping unit 3 comes into contact with the packer in the tubing, the locking claw 11 at the lower end of the reconnection locking seal device 6 will retract under the gravity of the pumping unit 3 and the upper sucker rod 2, so that the locking claw 11 is locked at the lower support seat 17 of the packer 7, thus completing the fixation of the pumping unit 3 and the reconnection locking seal device 6. At this time, the first non-metallic seal 8, the second non-metallic seal 9, and the metal seal 10 on the upper part of the reconnection locking seal device 6 will respectively fit with the first non-metallic seal seat 14, the second non-metallic seal seat 15, and the metal seal seat 16 in the packer to form a mechanical seal. Subsequently, following step S5 of the above-described method for operating a rod pump production tubing string with a stationary tubing string, the sealing performance of the rod pump production tubing string is verified. After the sealing performance verification is passed, the position of the plunger 4 connected to the lower end of the sucker rod 2 within the pump barrel 5 is adjusted by raising or lowering it to ensure that the plunger 4 can function normally within the pump barrel 5. As production progresses, if the fluid level in the wellbore changes and the position of the pump 3 needs to be adjusted before resuming production, the packer 7 should be unsealed using a desealing tool while maintaining the tubing condition. Then, the pump 3 and sucker rod 2 should be removed, and finally, the operation should be carried out according to the above-described method for operating a rod pump production tubing string. Compared to the conventional method for adjusting the position of the pump in rod pump production, this method effectively reduces the number of tubing operations and improves the production time and efficiency of the oil well.

[0053] Unless otherwise specified, the equipment components involved in the above embodiments are all conventional equipment components, and the structural settings, working methods or control methods involved are all conventional settings, working methods or control methods in the art unless otherwise specified.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Any other modifications or equivalent substitutions made by those skilled in the art to the technical solutions of the present invention, as long as they do not depart from the spirit and scope of the technical solutions of the present invention, should be covered within the scope of the claims of the present invention.

Claims

1. A stationary tubing string for rod pump oil production, characterized in that, include: The oil pipe (1) and packer (7) are provided. An oil pump (3) is installed inside the oil pipe (1). The oil pump (3) has a pump barrel (5). A plunger (4) is installed inside the pump barrel (5). A sucker rod (2) is connected to the top of the plunger (4). The packer (7) is located below the oil pump (3) inside the oil pipe (1). A reconnection locking seal device (6) is inserted and connected to the inner wall of the packer (7). The top of the reconnection locking seal device (6) is... The part is connected to the oil pump (3); the reconnection locking sealing device (6) includes a sealing cylinder, and a seal is sleeved on the outside of the sealing cylinder; a locking claw (11) is connected to the bottom of the reconnection locking sealing device (6); the packer (7) includes a hollow cylinder, and a tooth (12) is provided on the top outside of the hollow cylinder, a sealing rubber sleeve (13) is sleeved on the outside of the hollow cylinder, and a sealing seat and a support seat (17) are provided on the inside of the hollow cylinder.

2. The oil production tubing string for a stationary tubing rod pump according to claim 1, characterized in that, The seal includes a non-metallic seal and a metallic seal (10), with the non-metallic seal disposed above the metallic seal (10).

3. The oil production tubing string for a stationary tubing rod pump according to claim 2, characterized in that, The non-metallic seal includes a first non-metallic seal (8) and a second non-metallic seal (9). The first non-metallic seal (8), the second non-metallic seal (9) and the metal seal (10) are sequentially fitted on the outer side of the sealing cylinder from top to bottom.

4. The oil production tubing string for a stationary tubing rod pump according to claim 2, characterized in that, The metal seal (10) is made of steel ring, and the non-metal seal is made of rubber ring.

5. The oil production tubing string for a stationary tubing rod pump according to claim 1, characterized in that, The sealing seat includes a non-metallic sealing seat and a metallic sealing seat (16), wherein the non-metallic sealing seat is disposed above the metallic sealing seat (16).

6. The oil production tubing string for a stationary tubing rod pump according to claim 5, characterized in that, The non-metallic sealing seat includes a non-metallic sealing seat (14) and a second non-metallic sealing seat (15). The inner side of the hollow cylinder is fitted with a sealing rubber tube (13), a first non-metallic sealing seat (14) and a second non-metallic sealing seat (15) from top to bottom.

7. The oil production tubing string for a stationary tubing rod pump according to claim 1, characterized in that, The packer (7) is a removable packer.

8. The oil production tubing string for a stationary tubing rod pump according to claim 1, characterized in that, The pump cylinder (5) is provided with an embedded threaded female thread at its lowest end.

9. A method for operating a stationary tubing rod pump oil production tubing string according to any one of claims 1 to 8, characterized in that, Includes the following steps: The packer (7) is lowered into the corresponding position designed in the oil pipe (1). By pressing, the jaws (12) at the upper end of the packer (7) are opened outward, and the sealing sleeve (13) is expanded under pressure to achieve the setting of the packer (7). The combined oil pump (3) and the reconnection locking seal device (6) are connected. When the reconnection locking seal device (6) comes into contact with the packer (7), the locking claw (11) retracts under gravity and locks at the lower support seat (17) of the packer (7). The position of the plunger (4) connected to the lower end of the sucker rod in the pump barrel (5) is adjusted by lifting or lowering the sucker rod (2).

10. The working method of a stationary tubing rod pump oil production tubing string according to claim 9, characterized in that, When the fluid level in the wellbore changes, while keeping the tubing (1) in the same condition, first unseal the packer (7), and then take out the oil pump (3) and sucker rod (2).

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