Hydraulic pipe column anchor

Abstract

The invention belongs to the field of oilfield exploitation, and particularly relates to a hydraulic tubular column anchor which comprises an upper connector, a lower connector and a lower center pipe, the lower connector is connected to the bottom end of the lower center pipe and fixedly connected with the lower center pipe, an anchor body is installed outside the lower center pipe, and the anchor body is fixedly connected with the lower center pipe. The anchor body comprises a sheath, a slip, a plate spring, an upper cone, a lower cone and a lifting and hanging pin; a pressure relief lifting and hanging mechanism is connected to the upper portion of the anchor body and comprises an upper center pipe and a lifting and hanging sleeve, and a pressure relief hole is formed in the position, close to the bottom end of the upper center pipe, of the side face of the upper cone. The lower part of the anchor body is connected with an extrusion propulsion mechanism; sufficient anchoring force can be provided for the tubular column, jam releasing can be carried out through an auxiliary jam releasing means, and operation is easy and convenient.

Description

Technical Field

[0001] The invention belongs to the field of oil field exploitation, and in particular relates to a hydraulic pipe column anchor. Background Art

[0002] During the development of oil fields, pipe anchors are often used in production pipes. The pipes are composed of: oil pipe + oil pump + pipe anchor + packer + auxiliary tools, etc. Its function is to prevent the pipe from creeping up and down during the production and pumping process, which leads to the breakage and wear of the pipe. More importantly, the creep of the pipe will cause the packer rubber tube to wear, damage, and deformation, resulting in a serious shortening of the effective period of the packer plugging, increasing the workload of minor repairs, affecting the efficient extraction of crude oil, and increasing production costs. At present, there are two most commonly used anchors in production, one is a hydraulic anchor and the other is an expansion anchor. The principle of the hydraulic anchor is that the pressure of the liquid column in the pipe directly acts on the anchor teeth of the anchor. The anchor teeth are circular cylinders embedded in the main body of the anchor. The hydraulic pressure acts on the circular cylinder so that the anchor teeth are squeezed on the casing wall to achieve the function of anchoring the pipe. Due to the structural characteristics of this type of anchor, the cross-sectional area of ​​the circular cylinder is limited, and the extrusion force formed is limited, so its anchoring force is also small. The expansion anchor is a two-way slip anchoring device. Its principle is to use the relative rotation of the thread to push the sleeve forward relatively, squeeze the two-way slip cone surface, and make the slip firmly anchored on the casing wall. Its characteristic is that the anchoring force is large, and the disadvantage is that the operation is relatively complicated. When unsealing and unblocking, the lifting force is often too large, and there is a lack of auxiliary means of unblocking. Summary of the invention

[0003] The purpose of the present invention is to solve the problems of large unlocking force and poor anchoring effect in the prior art, thereby providing a hydraulic pipe string anchor, which can provide sufficient anchoring force for the pipe string and can be unlocked by auxiliary unlocking means, and is simple and convenient to operate.

[0004] The objective of the present invention is achieved in this way: a hydraulic pipe column anchor comprises an upper joint, a lower joint and a lower center tube, the lower joint is connected to the bottom end of the lower center tube, the lower joint is fixedly connected to the lower center tube, an anchor body is installed on the outside of the lower center tube, the anchor body comprises a sleeve, a slip, a leaf spring, an upper cone, a lower cone, and a lifting pin, the upper cone and the lower cone are sleeved on the outside of the lower center tube, the sleeve is sleeved on the outside of the upper cone and the lower cone, and the upper cone is hung on the step surface of the inner side surface of the sleeve, the lower cone is hung on the lifting pin on the side surface of the sleeve, a slot is provided on the side surface of the sleeve, a slip is provided in the slot, the slip is located between the upper cone and the lower cone, the upper The lower end surfaces respectively adopt a conical structure, and the upper and lower end surfaces of the slip are respectively slidably connected with the conical surfaces of the upper cone and the lower cone, the slips are evenly distributed around the lower center tube, and a leaf spring is arranged between the slips and the sleeve; a pressure relief lifting mechanism is connected to the top of the anchor body, and the pressure relief lifting mechanism comprises an upper center tube and a lifting sleeve, the upper center tube is connected to the upper cone by a thread, the upper center tube is fixedly connected to the upper joint, the lifting sleeve is arranged on the outside of the upper center tube, and the lifting sleeve is fixedly connected to the upper center tube and connected to the upper cone by a thread, and a pressure relief hole is arranged on the side of the upper cone near the bottom end of the upper center tube; an extrusion and propulsion mechanism is connected to the bottom of the anchor body.

[0005] Furthermore, the extrusion propulsion mechanism includes a spacer sleeve, a cylinder sleeve, a piston, and a control pin. The spacer sleeve and the piston sleeve are arranged on the outside of the lower center tube, and the piston is located between the spacer sleeve and the lower joint. The cylinder sleeve is arranged on the outside of the spacer sleeve and the piston. The piston is hung on the step surface on the inner side surface of the cylinder sleeve, and the piston is connected to the lower center tube in an up and down sliding manner. The cylinder sleeve and the lower joint are connected by a control pin, and a pressure relief hole is arranged on the side wall of the cylinder sleeve.

[0006] Furthermore, the spacer sleeve and the lower center pipe are fixedly connected via threads.

[0007] Furthermore, the lower joint is connected to the lower center pipe via threads.

[0008] Furthermore, the upper central pipe and the upper joint are connected via threads.

[0009] Furthermore, the upper cone and the lower central tube are connected via reverse threads.

[0010] Beneficial effects of the present invention: 1. The present invention adopts a bidirectional slip to anchor the pipe string, providing an anchoring force in both the upper and lower directions for the pipe string, so that the pipe string can neither move upward nor downward. The slip is pushed by a piston, and the force of the piston can be appropriately designed according to the situation. In the working state, the pressure of the liquid column in the pipe string pushes the piston, so that the slip is firmly anchored on the casing wall. The anchoring force is large and can provide sufficient anchoring force for the pipe string. When unblocking, the oil pipe is rotated forward to open the oil drain mechanism to drain the liquid column pressure in the pipe string, release the piston thrust, and the slip cone loses thrust. The pipe string is lifted to recover the slip. If the lifting force is too large to unblock, the oil drain channel can be closed and reverse pressure can be applied from the casing to assist in unblocking. 2. The present invention can not only eliminate the influence of pipe creep on the plugging performance of the packer or the supporting tools of the pipe, but also has a large anchoring force, is firmly and reliably anchored, and puts the pipe in a better working state, which is beneficial to pumping production and extending the life of the pipe. At the same time, since it has a pipe pressure relief function, during the construction operation of pulling out the pipe, the oil in the pipe can flow back to the oil well through the pressure relief channel, avoiding the oil in the oil pipe from being discharged to the wellhead and causing pollution. The invention utilizes the hydraulic pressure of the pipe column or the ground pump to press the cava, adopts bidirectional anchoring, and rotates the oil pipe in the forward direction to release the pressure and lift it up to release the jam, and has reliable performance and simple structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments of the present invention or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0012] Figure 1 The present invention is a schematic diagram of the cross-sectional structure of a hydraulic pipe string anchor.

[0013] Description of reference numerals: 1. Lower center tube; 2. Lower joint; 3. Upper joint; 4. Sheath; 5. Slip; 6. Leaf spring; 7. Upper cone; 8. Lower cone; 9. Lifting pin; 10. Slot hole; 11. Upper center tube; 12. Lifting sleeve; 13. Pressure relief hole; 14. Spacer; 15. Cylinder liner; 16. Piston; 17. Control pin. DETAILED DESCRIPTION

[0014] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0015] In the description of the present invention, it is necessary to understand that the terms "length", "width", "up", "down", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0016] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0017] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0018] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0019] In one embodiment of the present invention, Figure 1As shown, a hydraulic pipe column anchor comprises an upper joint 3, a lower joint 2 and a lower center pipe 1, wherein the lower joint 2 is connected to the bottom end of the lower center pipe 1, the lower joint 2 is fixedly connected to the lower center pipe 1, an anchor body is installed on the outside of the lower center pipe 1, the anchor body comprises a sleeve 4, a slip 5, a leaf spring 6, an upper cone 7, a lower cone 8, and a lifting pin 9, the upper cone 7 and the lower cone 8 are sleeved on the outside of the lower center pipe 1, the sleeve 4 is sleeved on the outside of the upper cone 7 and the lower cone 8, and the upper cone 7 is hung on the step surface of the inner side surface of the sleeve 4, the lower cone 8 is hung on the lifting pin 9 on the side surface of the sleeve 4, a slot 10 is provided on the side surface of the sleeve 4, a slip 5 is provided in the slot 10, the slip 5 is located between the upper cone 7 and the lower cone 8, and the upper and lower end surfaces of the slip 5 A conical structure is adopted respectively, and the upper and lower end faces of the slip 5 are slidably connected with the conical surfaces of the upper cone 7 and the lower cone 8 respectively, the slip 5 is evenly distributed around the lower center tube 1, and a leaf spring 6 is arranged between the slip 5 and the sleeve 4; a pressure relief lifting mechanism is connected to the top of the anchor body, and the pressure relief lifting mechanism includes an upper center tube 11 and a lifting sleeve 12, the upper center tube 11 is connected to the upper cone 7 by a thread, the upper center tube 11 is fixedly connected to the upper joint 3, the lifting sleeve 12 is sleeved on the outside of the upper center tube 11, and the lifting sleeve 12 is fixedly connected to the upper center tube 11 and connected to the upper cone 7 by a thread, and a pressure relief hole 13 is arranged on the side of the upper cone 7 near the bottom end of the upper center tube 11; an extrusion and propulsion mechanism is connected to the bottom of the anchor body.

[0020] In one embodiment of the present invention, Figure 1 As shown, the extrusion and propulsion mechanism includes a spacer sleeve 14, a cylinder sleeve 15, a piston 16, and a control pin 17. The spacer sleeve 14 and the piston 16 are sleeved on the outside of the lower center tube 1, and the piston 16 is located between the spacer sleeve 14 and the lower joint 2. The cylinder sleeve 15 is sleeved on the outside of the spacer sleeve 14 and the piston 16. The piston 16 is hung on the step surface on the inner side of the cylinder sleeve 15, and the piston 16 is connected to the lower center tube 1 in an up and down sliding manner. The cylinder sleeve 15 is connected to the lower joint 2 by a control pin 17, and a pressure relief hole is provided on the side wall of the cylinder sleeve 15.

[0021] In one embodiment of the present invention, Figure 1As shown, a hydraulic pipe column anchor includes a hydraulic seating structure and an oil leakage lifting and hanging mechanism, wherein the hydraulic seating mechanism includes a lower joint 2, a lower center pipe 1, a piston 16, a control pin 17, a cylinder sleeve 15, a spacer 14, a lower cone 8, a sheath 4, a leaf spring 6, a slip 5, an upper cone 7, a lifting and hanging pin 9, etc. The lower center pipe 1 is cylindrical, and the upper, middle and lower parts are provided with external threads and two hydraulic seating holes. The lower joint 2 is stepped inside and outside, and the inner step is provided with threads. The inner and outer walls of the upper cone 7 are The cylindrical step-type structure has a conical surface at the lower end and an oil drain channel in the middle. The inner step of the upper cone 7 is provided with upper and lower threads, and the upper end of the outer step is provided with an outer thread. The upper end thread of the inner step of the upper cone 7 is a reverse thread. The outer thread at the lower end of the lower center tube 1 is connected with the inner step thread of the lower joint 2, and the outer thread at the upper end of the lower center tube 1 is connected with the lower end thread of the inner step of the upper cone 7. The hydraulic seat mechanism is located at the periphery of the upper cone 7, the lower center tube 1 and the lower joint 2. The partition The sleeve 14 is provided with an inner thread, which is connected to the middle thread of the lower center tube 1 through the inner thread. The piston 16 is cylindrical and sleeved on the outer periphery of the lower center tube 1, and is located between the lower end surface of the spacer sleeve 14 and the upper end surface of the lower joint 2. The lower cone 8 is cylindrical in shape inside and outside, with a conical surface at the upper end, and the outer step of the lower end is provided with a thread. The cylinder sleeve 15 is cylindrical, with a step on the inner circle, a thread on the upper step, a pressure discharge hole on the middle step, and a pin threaded hole on the lower step. The inner step of the lower cone 8 is provided with a threaded hole on the lower step. The step is sleeved on the lower center tube 1, the outer thread at the lower end of the lower cone 8 is threadedly connected with the upper step of the cylinder sleeve 15, the cylinder sleeve 15 is sleeved on the lower cone 8, the spacer 14, the piston 16 and the outer periphery of the lower joint 2, the upper end face of the piston 16 is stuck on the middle step of the cylinder sleeve 15, and the lower end face is supported on the upper end face of the lower joint 2, the front end of the control pin 17 is inserted into the outer step of the lower joint 2, and is connected with the threaded hole of the cylinder sleeve 15 through a thread. The upper end of the sleeve 4 is provided with a cylindrical step, and 8 slots 10 for placing the slips 5 are opened in the middle, and a pin threaded hole is provided in the lower part. The sleeve 4 is hung on the outer step of the upper cone 7 through the internal step. The upper and lower end faces of the two-way slip 5 are conical surfaces, and a groove is provided in the middle, which is placed in the slot 10 in the middle position of the sleeve 4. The upper conical surface of the two-way slip 5 is close to the conical surface of the upper cone 7, and there is a partition between the middle slot 10 of the sleeve 4. The leaf spring 6 is placed between the partition and the middle groove of the two-way slip 5. The lower cone 8 is located inside the sleeve 4, and the conical surface of the lower cone 8 is close to the conical surface of the lower end of the two-way slip 5. The lower cone 8 is provided with a step groove on the outside, and the front end of the lifting pin 9 is inserted into the step groove on the outside of the lower cone 8 to hang the sleeve 4 and the lower cone 8 together.

[0022] The oil leakage lifting mechanism includes an upper joint 3, an upper center pipe 11 and a lifting sleeve 12. The upper center pipe 11 is cylindrical, and the outer surface is a stepped structure. The upper end is provided with an outer thread, and the middle step is provided with a reverse outer thread. The upper center pipe 11 is connected to the reverse inner thread on the upper end of the upper cone 7 through the reverse outer thread on the middle step. The inner wall of the lifting sleeve 12 is provided with large and small steps, and the inner wall of the step with a large diameter is provided with an inner thread. The lifting sleeve 12 is sleeved on the periphery of the upper center pipe 11, and the inner wall thread of the lifting sleeve 12 is connected to the outer thread on the upper end of the upper cone 7. The upper joint 3 is provided with upper and lower inner wall threads, and is connected to the upper center pipe 11 through the lower inner wall thread.

[0023] The present invention uses a bidirectional slip 5 to anchor the tubing. The slip 5 is pushed by a piston 16 when it is stuck. The force of the piston 16 can be appropriately designed according to the situation. In the working state, the pressure of the liquid column in the tubing pushes the piston 16, so that the slip 5 is firmly anchored on the casing wall. The anchoring force is large and can provide sufficient anchoring force for the tubing. When unblocking, the oil pipe is rotated forward to open the oil leakage mechanism to leak the pressure of the liquid column in the tubing, release the thrust of the piston 16, and the tapered surface of the slip 5 loses the thrust. The tubing is lifted to recover the slip 5. If the lifting force for unblocking is too large, the oil leakage channel can be closed and the casing can be pressed in the reverse direction to assist in unblocking. The tubing has a pressure relief function. During the construction operation of lifting the tubing, the oil in the tubing can flow back into the oil well through the pressure relief hole 13 to avoid the oil in the tubing from being discharged to the wellhead and causing pollution.

[0024] The implementation process includes the following steps: The first step is to connect the hydraulic string anchor, oil pump, packer and other supporting tools together according to production needs. For example, the connection sequence is: oil pipe + oil pump + oil pipe + a hydraulic string anchor + oil pipe + packer, etc., and deliver the hydraulic string anchor to the oil well production design position through the pipe string; The second step is to connect the ground cement truck and other pumping equipment with the pipe string according to the design requirements, inject water pressure into the pipe string, and set the hydraulic pipe string anchor, packer, etc. The water pressure enters the piston cavity through the pipe string, the upper joint 3, and the water inlet channel on the lower center pipe 1, pushing the piston 16 and the lower cone 8 forward. The thrust of the piston 16 and the lower cone 8 is directly or indirectly transmitted to the control pin 17 through the cylinder sleeve 15, and the control pin 17 is cut off. The piston 16 and the lower cone 8 continue to move forward, pushing the slip 5 to protrude and expand outward along the cone surface of the upper and lower cones 8, and then close to the casing wall. As the pressure continues to increase, the slip 5 is firmly anchored on the casing wall. After that, the sealing and pressure equipment is removed, and the inner cavity of the oil pipe is filled with a liquid column. Under the pressure of the liquid column, the thrust of the piston 16 and the upper cone 7 always anchors the slip 5 on the casing wall, completing the anchoring process; The third step is that during the production process, the tubing is always filled with oil, and the oil column generates pressure, squeezing the piston 16 and the upper cone 7, so that the slip 5 is firmly anchored on the casing wall, playing the role of anchoring the tubing. In addition, when the lower matching packer is subjected to downward thrust, the force is transmitted to the lower joint 2, the center pipe and the upper cone 7 of a hydraulic tubing anchor through the packer and the oil pipe, and the slip 5 is squeezed through the conical surface of the upper cone 7, so that the slip 5 is firmly anchored on the casing. When the lower matching packer is subjected to upward thrust, the force is transmitted to the oil pipe and the lower cone 8 of the hydraulic tubing anchor, thereby firmly anchoring the slip 5 on the casing. The tubing support force and the anchoring force of the slip 5 prevent the packer from moving. The fourth step is that when the production string needs to be pulled out after a period of production, the wellhead is removed, the string is rotated forward, and the rotation torque is transmitted to the upper joint 3 and the upper center pipe 11 of a hydraulic string anchor through the string. The upper center pipe 11 rotates relative to the upper cone 7. Under the action of the reverse thread, the upper center pipe 11 moves upward relative to the upper cone 7, leaving the pressure relief hole 13. At this time, the inside and outside of the string are connected, and the liquid in the string flows out of the string. The pressure generated by the liquid column in the pipe is eliminated, and the squeezing force of the piston 16 and the upper cone 7 on the slip 5 is eliminated. After stopping the rotation of the string, the string is lifted, and the lifting force of the string is transmitted to the lifting sleeve 12, the upper cone 7 and the sheath 4 through the upper joint 3 and the upper center pipe 11, forcing the slip 5 to be recovered, and realizing the unblocking action.

[0025] The above are only preferred embodiments of the present invention, and only specifically describe the technical principles of the present invention. These descriptions are only for explaining the principles of the present invention and cannot be interpreted as limiting the scope of protection of the present invention in any way. Based on the explanations here, any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention, and other specific implementations of the present invention that can be associated with by technicians in this field without creative labor, should be included in the scope of protection of the present invention.

Claims

1. A hydraulic pipe string anchor, comprising an upper joint (3), a lower joint (2) and a lower center pipe (1), wherein the lower joint (2) is connected to the bottom end of the lower center pipe (1), the lower joint (2) and the lower center pipe (1) are fixedly connected, and an anchor body is installed outside the lower center pipe (1), characterized in that: The anchor body comprises a sheath (4), a slip (5), a leaf spring (6), an upper cone (7), a lower cone (8), and a lifting pin (9); the upper cone (7) and the lower cone (8) are sleeved on the outside of the lower center pipe (1); the sheath (4) is sleeved on the outside of the upper cone (7) and the lower cone (8); the upper cone (7) is hung on the step surface on the inner side of the sheath (4); the lower cone (8) is hung on the lifting pin (9) on the side of the sheath (4); the sheath ( 4) is provided with a slot hole (10), a slip (5) is provided in the slot hole (10), the slip (5) is located between the upper cone (7) and the lower cone (8), the upper and lower end surfaces of the slip (5) respectively adopt a conical structure, and the upper and lower end surfaces of the slip (5) are respectively slidably connected to the conical surfaces of the upper cone (7) and the lower cone (8), the slip (5) is evenly distributed around the lower center pipe (1), and a leaf spring (6) is provided between the slip (5) and the sleeve (4); A pressure relief lifting mechanism is connected to the upper part of the anchor body, and the pressure relief lifting mechanism comprises an upper center tube (11) and a lifting sleeve (12); the upper center tube (11) is connected to the upper cone (7) by means of threads, the upper center tube (11) is fixedly connected to the upper joint (3), the lifting sleeve (12) is sleeved on the outside of the upper center tube (11), and the lifting sleeve (12) is fixedly connected to the upper center tube (11) and connected to the upper cone (7) by means of threads; a pressure relief hole (13) is provided on the side surface of the upper cone (7) near the bottom end of the upper center tube (11); and an extrusion and propulsion mechanism is connected to the lower part of the anchor body.

2. A hydraulic pipe string anchor as claimed in claim 1, characterized in that: The extrusion and propulsion mechanism comprises a spacer sleeve (14), a cylinder sleeve (15), a piston (16), and a control pin (17); the spacer sleeve (14) and the piston (16) are sleeved on the outside of the lower center tube (1), and the piston (16) is located between the spacer sleeve (14) and the lower joint (2); the cylinder sleeve (15) is sleeved on the outside of the spacer sleeve (14) and the piston (16); the piston (16) is hung on a step surface on the inner side surface of the cylinder sleeve (15), and the piston (16) is slidably connected to the lower center tube (1) in an upward and downward manner; the cylinder sleeve (15) and the lower joint (2) are connected via the control pin (17); and a pressure relief hole is provided on the side wall of the cylinder sleeve (15).

3. A hydraulic pipe string anchor as claimed in claim 1, characterized in that: The spacer (14) and the lower center pipe (1) are fixedly connected via threads.

4. A hydraulic pipe string anchor as claimed in claim 1, characterized in that: The lower joint (2) is connected to the lower center pipe (1) via threads.

5. A hydraulic pipe string anchor as claimed in claim 1, characterized in that: The upper central pipe (11) and the upper joint (3) are connected via threads.

6. A hydraulic pipe string anchor as claimed in claim 1, characterized in that: The upper cone (7) and the lower center tube (1) are connected via reverse threads.

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