Stratum liquid pumping device

Abstract

The utility model relates to the technical field of devices for extracting fluid from strata, in particular to a strata fluid extraction device which comprises an upper pipe body and a lower pipe body, an inner ring table is arranged at the lower end of the upper pipe body, the upper end of the lower pipe body penetrates through a center hole of the inner ring table, a piston is arranged on the portion, stretching into the upper pipe body, of the lower pipe body, and the lower pipe body is connected with a packer. The piston is located above the inner ring table so that a liquid pumping cavity can be formed between the piston and the inner ring table when the upper pipe body moves downwards relative to the piston, and the lower pipe body is provided with an upper check valve structure and a lower check valve structure which allow liquid to flow upwards. A communicating hole for communicating the inner cavity of the lower pipe body with the liquid pumping cavity is formed between the upper check valve structure and the lower check valve structure on the lower pipe body; liquid pumping is achieved through relative movement of the upper pipe body and the lower pipe body of the stratum liquid pumping device, the stratum liquid pumping device can be tripped into a tubular column along with an oil pipe and a packer, and operation convenience is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of devices for extracting fluid from a stratum, in particular to a stratum liquid extraction device. Background Art

[0002] For newly developed oil wells, in order to understand the characteristics of the reservoir, it is necessary to sample, test and analyze the formation fluid. The liquid in the wellbore is often a mixture of fluids from multiple formations and working fluids (such as well washing fluids). In order to accurately obtain the target formation fluid, it is usually necessary to lower the pipe string to isolate the corresponding formation and extract a certain amount of target formation fluid, and then pull out the pipe string to bring the formation fluid to the surface. For sampling of formation fluid, a conventional plunger oil pump is currently used. For the downhole operation of the plunger oil pump, it is necessary to first lower the pump barrel of the oil pump and the oil pipe connected to it into the wellbore, and then lower the plunger of the oil pump and the sucker rod connected to it into the oil pipe. This requires two trips of pipe and rod strings, which is inconvenient. Utility Model Content

[0003] The utility model aims to provide a formation pumping device to solve the problem that two trips of pipe and rod strings are required when sampling formation fluid using a plunger oil pump, which is inconvenient.

[0004] The technical solution of the formation pumping device of the utility model is:

[0005] The formation pumping device comprises an upper tube body and a lower tube body, wherein the upper end of the upper tube body is provided with an upper connecting structure for connecting the oil pipe, the lower end of the upper tube body is provided with an inner ring platform, the upper end of the lower tube body passes through the central hole of the inner ring platform and the lower tube body and the inner ring platform are slidingly and sealingly matched, the part of the lower tube body extending into the upper tube body is provided with a piston matched with the inner wall of the upper tube body, and the lower tube body is provided with a lower connecting structure for connecting the packer below the upper tube body, the piston is located above the inner ring platform so that a pumping cavity is formed between the piston and the inner ring platform when the upper tube body moves downward relative to the piston, the lower tube body is provided with an upper check valve structure and a lower check valve structure for upward flow of liquid, and the lower tube body is provided with a connecting hole for connecting the lower tube body cavity with the pumping cavity between the upper check valve structure and the lower check valve structure in the up and down directions.

[0006] Furthermore, the upper check valve structure is arranged on the piston, and the piston has a central hole that can connect the inner cavity of the upper tube body and the inner cavity of the lower tube body. The upper check valve structure includes a blocking body movably arranged on the piston for blocking the central hole.

[0007] Furthermore, the blocking body is a sphere, and the piston is provided with a sealing surface that seals with the sphere.

[0008] Furthermore, an upward abutting surface is provided on the lower tube body below the inner ring platform, and a spring is sleeved outside the lower tube body, the upper end of the spring abuts against the lower end surface of the inner ring platform, and the lower end abuts against the upward abutting surface.

[0009] Furthermore, the lower tube body includes an inner tube and a lower joint connected to the lower end of the inner tube, and the upward abutting surface is arranged on the lower joint.

[0010] Furthermore, the lower tube body comprises an inner tube, the upper end of the inner tube passes through the inner ring platform and extends into the upper tube body, and the piston is connected to the inner tube.

[0011] Furthermore, the upper tube body comprises an outer tube, and a sealing ring is connected to the inner wall of the lower end of the outer tube, and the sealing ring constitutes the inner ring platform.

[0012] Furthermore, the lower check valve structure includes a valve seat and a valve ball. The valve seat is arranged on the inner wall of the lower tube body, and a matching surface for sealing with the valve ball is provided on the valve seat.

[0013] Furthermore, the upper connection structure is an upper joint provided at the upper end of the upper tube body.

[0014] Furthermore, the lower connecting structure is located above the lower check valve structure.

[0015] Beneficial effect: The utility model provides a formation pumping device which is convenient for lifting and lowering a pipe string. A set of pipe strings formed by connecting the upper pipe body of the formation pumping device to the oil pipe and the lower pipe body to the packer are lowered into the wellbore. After the packer is seated above the target formation, the lower pipe body is fixed, and the piston on the lower pipe body extending into the upper pipe body is fixed. At this time, the upper pipe body can be moved downward by lowering the oil pipe. The upper pipe body moves downward relative to the piston, so that the inner ring platform at the lower end of the upper pipe body moves downward away from the piston, thereby forming a pumping chamber between the piston and the inner ring platform. As the upper pipe body moves downward, the volume of the pumping chamber increases to form a negative pressure, so that the upper check valve structure remains closed and the lower check valve structure opens. The liquid in the lower pipe body below the upper check valve structure is sucked into the pumping chamber through the connecting hole, and then can be lifted up The oil pipe causes the upper pipe body to move upward, and the upper pipe body moves upward relative to the piston, so that the inner ring platform at the lower end of the upper pipe body moves upward and approaches the piston. As the upper pipe body moves upward, the volume of the pumping chamber decreases, and pressure is applied to the liquid therein, so that the upper single-flow valve structure opens and the lower single-flow valve structure closes. The liquid in the pumping chamber is discharged through the connecting hole and can enter the space in the upper pipe body above the upper single-flow valve structure, thereby realizing the pumping of the liquid in the wellbore. Through multiple pumping, the target formation fluid can be extracted and fill the lumen of the lower pipe body between the upper single-flow valve structure and the lower single-flow valve structure. In this way, the pipe string can be lifted out to complete the formation fluid sampling. Since the liquid pumping is realized by utilizing the relative movement of the upper pipe body and the lower pipe body of the formation pumping device, the formation pumping device can be lowered into the pipe string along with the oil pipe and the packer in one trip, thereby improving the convenience of the operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of an embodiment of the formation liquid pumping device of the utility model;

[0017] Figure 2 for Figure 1 Schematic diagram of the local structure at the piston.

[0018] In the figure: 1. upper joint; 2. first sealing ring; 3. outer tube; 4. upper valve ball; 5. piston; 6. second sealing ring; 7. connecting hole; 8. sealing ring; 9. third sealing ring; 10. inner tube; 11. spring; 12. lower joint; 13. connecting pipe; 14. lower valve ball; 15. lower valve seat; 100. pumping chamber; 200. packer. DETAILED DESCRIPTION

[0019] The upper tube body of the formation pumping device of the utility model is connected to the oil pipe, and the lower tube body is connected to the packer to form a set of pipe strings. After the pipe string is lowered into the wellbore and the packer is sealed above the target formation, the lower tube body is fixed, and the piston on the lower tube body that extends into the upper tube body is fixed. At this time, the upper tube body can be moved downward by lowering the oil pipe, and the upper tube body moves downward relative to the piston, so that the inner ring platform at the lower end of the upper tube body moves downward away from the piston, thereby forming a pumping chamber between the piston and the inner ring platform. As the upper tube body moves downward, the volume of the pumping chamber increases to form a negative pressure, so that the upper check valve structure remains closed and the lower check valve structure opens, and the liquid in the lower tube body and below the upper check valve structure is sucked into the pumping chamber through the connecting hole, and then the upper tube body can be moved upward by lifting the oil pipe. The piston moves upward, so that the inner ring platform at the lower end of the upper tube body moves upward and approaches the piston. As the upper tube body moves upward, the volume of the pumping chamber decreases, and pressure is applied to the liquid therein, so that the upper single-flow valve structure opens and the lower single-flow valve structure closes. The liquid in the pumping chamber is discharged through the connecting hole and can enter the space in the upper tube body above the upper single-flow valve structure, thereby realizing the pumping of the liquid in the wellbore. Through multiple pumping, the target formation fluid can be extracted and fill the tube cavity between the upper single-flow valve structure and the lower single-flow valve structure of the lower tube body. In this way, the formation fluid sampling can be completed by lifting the pipe string. Since the liquid pumping is realized by the relative movement of the upper tube body and the lower tube body of the formation pumping device, the formation pumping device can be lowered into the pipe string along with the oil pipe and the packer in one trip, thereby improving the convenience of the operation.

[0020] Embodiment of the formation pumping device of the utility model:

[0021] like Figure 1 and Figure 2As shown, the formation pumping device includes an upper tube body and a lower tube body, the upper tube body includes an outer tube 3, the upper end of the outer tube 3 is provided with an upper joint 1, and the lower end is provided with a sealing ring 8. The lower tube body includes an inner tube 10, the upper end of the inner tube 10 is provided with a piston 5, and the lower end is provided with a lower joint 12, the lower joint 12 is connected to a connecting pipe 13, and the connecting pipe 13 is provided with a lower connecting structure for connecting the packer 200. The upper end of the inner tube 10 passes through the center hole of the sealing ring 8, the piston 5 is located in the outer tube 3 of the upper tube body, and the piston 5 is located above the sealing ring 8. The outer tube 3 constitutes a cylinder body that cooperates with the piston 5. When the formation pumping device is used, the cylinder body moves up and down while the piston 5 does not move. The piston 5 has an end face facing the sealing ring 8 so that a pumping chamber 100 is formed between the piston 5 and the sealing ring 8 when the upper tube body moves downward relative to the piston 5. The lower tube body is provided with an upper check valve structure and a lower check valve structure for upward flow of liquid. The lower tube body is provided with a connecting hole 7 between the upper check valve structure and the lower check valve structure in the up and down directions. The connecting hole 7 is used to connect the inner cavity of the lower tube body with the pumping chamber 100 so as to cooperate with the upper check valve structure and the lower check valve structure to realize the extraction of formation fluid when the upper tube body moves up and down relative to the lower tube body.

[0022] The upper joint 1 has a central hole that passes through from top to bottom. The upper end of the upper joint 1 is provided with an internal thread for connecting the upper oil pipe. The lower end of the upper joint 1 is provided with an external thread and a sealing ring mounting groove. The upper end of the outer tube 3 is provided with an internal thread for threaded connection with the lower end of the upper joint 1. The sealing ring mounting groove at the lower end of the upper joint 1 is provided with a first sealing ring 2 to seal the upper joint 1 with the outer tube 3. The upper joint 1 that is sealed and threadedly connected with the outer tube 3 is convenient for adapting and connecting the oil pipe.

[0023] The inner wall of the outer tube 3 is smooth, and the lower end of the outer tube 3 is provided with an internal thread. The sealing ring 8 is provided with an external thread. The sealing ring 8 is threadedly connected to the lower end of the outer tube 3 and is located inside the outer tube 3. The sealing ring 8 is sealed with the outer tube 3. The sealing ring 8 constitutes an inner ring platform of the upper tube body opposite to the piston 5, and the inner ring platform is located at the lower end of the upper tube body. Two sealing ring installation grooves are provided on the inner circumference of the sealing ring 8, and a third sealing ring 9 is installed in the sealing ring installation grooves to form a seal with the outer circumference of the inner tube 10.

[0024] The upper end of the inner tube 10 extending into the outer tube 3 is provided with an external thread, and the piston 5 has a central hole that passes through from top to bottom. The central hole of the piston 5 includes an upper tapered hole section and a lower connecting hole section. The lower connecting hole section is provided with an internal thread so that the piston 5 is connected to the upper end of the inner tube 10. The conical surface of the upper tapered hole section constitutes an upper valve seat. The upper check valve structure is arranged on the piston 5. The upper check valve structure includes an upper valve seat and an upper valve ball 4. When the upper valve ball 4 falls on the upper valve seat, the central hole of the piston 5 can be blocked. The outer diameter of the piston 5 is adapted to the inner diameter of the outer tube 3 so that the outer tube 3 can slide relative to the piston 5. Two sealing ring installation grooves are provided on the outer peripheral surface of the piston 5, and a second sealing ring 6 is installed in the sealing ring installation grooves, so that a seal is formed between the outer peripheral surface of the piston 5 and the inner peripheral surface of the outer tube 3. The piston 5 and the inner tube 10 are arranged separately, which is convenient for the production of the lower tube body. The upper check valve structure is arranged on the piston 5, which has a simple structure and is easy to install.

[0025] The lower end face of the piston 5 faces the upper end face of the sealing ring 8. When the outer tube 3 moves relative to the piston 5, the piston 5 and the sealing ring 8 are separated from each other to form a pumping chamber 100 between the two. The pumping chamber 100 is an annular cavity surrounded by the piston 5, the sealing ring 8, the outer tube 3, and the inner tube 10. A connecting hole 7 for communicating with the pumping chamber 100 is provided on the inner tube 10 below and adjacent to the piston 5. The connecting hole 7 is used to connect the inner cavity of the inner tube 10 with the pumping chamber 100. When the upper valve ball 4 does not fall on the upper valve seat, the center hole of the piston 5 can connect the space above the piston 5 in the inner cavity of the outer tube 3 with the inner cavity of the inner tube 10. The valve ball constitutes a plugging body for blocking the center hole of the piston 5. The plugging body is a sphere. The upper conical hole section of the piston 5 constitutes a sealing surface that seals with the sphere. The upper valve ball 4 and the upper valve seat cooperate to form a one-way valve structure for upward one-way flow of liquid. The structure is simple and reliable. When the upper tube body slides downward relative to the lower tube body, the third sealing ring 9 can keep the sealing ring 8 and the inner tube 10 sealed, and the second sealing ring 6 can keep the piston 5 and the outer tube 3 sealed, so that negative pressure is formed in the liquid extraction chamber 100, thereby sucking the liquid in the inner chamber of the inner tube 10.

[0026] The lower end of the inner tube 10 is provided with an external thread, the lower joint 12 has a central hole that runs through from top to bottom, the upper end of the lower joint 12 is provided with an internal thread to be threadedly connected with the lower end of the inner tube 10, and the lower end of the lower joint 12 is provided with an external thread to be connected with the connecting pipe 13. The inner tube 10 is sheathed with a spring 11, which is a compression spring. The spring 11 is located between the sealing ring 8 and the lower joint 12. The upper end of the spring 11 abuts against the lower end surface of the sealing ring 8, and the lower end abuts against the upper end surface of the lower joint 12. The upper end surface of the lower joint 12 constitutes an upward abutting surface, which is convenient for installing the spring 11. Under the elastic force of the spring 11, the lower end surface of the piston 5 can be tightly abutted against the upper end surface of the sealing ring 8 when the upper pipe body is not moved downward, so as to avoid the upper pipe body from moving relative to the lower pipe body during the process of lowering the pipe string into the wellbore.

[0027] A lower connecting structure for connecting the packer 200 is provided on the lower pipe body below the upper pipe body. The lower connecting structure is provided on the connecting pipe 13. The part of the connecting pipe 13 fixed with the packer 200 constitutes the lower connecting structure. A lower check valve structure is provided in the connecting pipe 13 so that the lower connecting structure is located above the lower check valve structure, so as to facilitate the use of the hydraulically seated packer 200. The packer 200 is a hydraulically seated bidirectional slip packer 200. The packer 200 is used to seal the annulus between the connecting pipe 13 and the wellbore above the target formation to be sampled. The space below the packer 200 is connected to the inner cavity of the connecting pipe 13. The lower check valve structure includes a lower valve seat 15 and a lower valve ball 14. The outer peripheral surface of the lower valve seat 15 is provided with an external thread. The inner wall of the connecting pipe 13 is provided with an internal thread for threading the lower valve seat 15. The lower valve seat 15 has a central hole that passes through from top to bottom. The central hole of the lower valve seat 15 has an upward tapered hole section. The inner wall surface of the tapered hole section constitutes a mating surface for sealing with the lower valve ball 14. When the lower valve ball 14 falls on the corresponding mating surface, the upper and lower spaces can be separated. The lower valve ball 14 and the lower valve seat 15 cooperate to form a check valve structure for upward one-way flow of liquid. The structure is simple and reliable.

[0028] When in use, the upper joint 1 of the formation pumping device is connected to the oil pipe, and the packer 200 is connected to the connecting pipe 13. A screen pipe and a wire plug can be connected below the connecting pipe 13 to form a pumping pipe string. The upper valve ball 4 is not lowered into the well with the pipe string first to facilitate the seating of the packer 200. After the pipe string is lowered into the wellbore and a position is set, and the packer 200 is seated above the formation, the valve ball 4 is dropped. After the upper valve ball 4 falls onto the upper valve seat, the pipe string is continued to be lowered. The oil pipe above the formation pumping device moves downward with the upper pipe body. Under the fixing action of the packer 200, the lower pipe body does not move, and the sealing ring 8 compresses the spring 11 downward and separates from the piston 5. The annular space volume between the upper pipe body and the lower pipe body between the sealing ring 8 and the piston 5 increases to form a pumping cavity 100, the connecting hole 7 connects the pumping chamber 100 with the inner cavity of the inner tube 10 below the piston 5. Under the action of negative pressure suction, the upper valve ball 4 remains sealed with the upper valve seat, and the lower valve ball 14 leaves the lower valve seat 15 upward, so as to extract the fluid from the formation below the packer 200. The formation fluid flows from the formation into the wellbore, and by lifting the tubing string, the oil pipe above the formation pumping device moves up with the upper pipe body, and the sealing ring 8 moves upward close to the piston 5, and the volume of the pumping chamber 100 decreases. The liquid in the pumping chamber 100 enters the inner cavity of the inner tube 10 from the connecting hole 7. Under the action of pressure, the upper valve ball 4 leaves the upper valve seat, and the lower valve ball 14 is sealed with the lower valve seat 15, and the liquid is sent to the space above the upper check valve structure of the outer tube 3 through the opened upper check valve structure. By lifting and lowering the pipe string several times, the liquid below the packer 200 is repeatedly sucked, and the formation fluid can eventually fill the space between the upper check valve structure and the lower check valve structure in the inner cavity of the inner tube 10, and the target formation fluid sample can be obtained by pulling out the pipe string. The formation fluid pumping device is used to pump liquid, and only one trip of the pipe string is required, which is conducive to simplifying the pipe string structure and facilitating operation, and is suitable for extracting liquid samples with relatively small demand in the wellbore.

[0029] In other implementations, the inner tube may also pass upward through the center hole of the piston, and the upper check valve structure is separately arranged at the upper end of the inner tube.

[0030] In other implementations, a blocking cover may also be hinged on the piston. The blocking cover can be flipped upward to open the center hole of the piston. When covering the piston, the center hole is blocked, and the blocking cover constitutes a blocking body.

[0031] In other implementations, the spring may not be provided, and the sealing ring and the inner tube may be pre-fixed by shear pins. When the upper tube body is moved downward, the shear pins are sheared off to cause the upper tube body to move downward relative to the piston.

[0032] In other embodiments, an outer ring platform is integrally provided on the outer circumferential surface of the inner tube, and an upward abutting surface is provided on the outer ring platform.

[0033] In other implementations, the inner tube and the sealing ring may also be provided integrally.

[0034] In other implementations, the upper joint may not be provided, and a threaded section directly connected to the oil pipe is provided at the upper end of the upper connecting pipe, and the threaded section constitutes an upper connecting structure.

[0035] Finally, it should be noted that the above is only a preferred embodiment of the utility model and is not intended to limit the utility model. Although the utility model is described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions recorded in the above embodiments without creative work, or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A formation pumping device, characterized in that: It comprises an upper tube body and a lower tube body, the upper end of the upper tube body is provided with an upper connecting structure for connecting the oil pipe, the lower end of the upper tube body is provided with an inner ring platform, the upper end of the lower tube body passes through the central hole of the inner ring platform and the lower tube body and the inner ring platform are slidingly and sealingly matched, the part of the lower tube body extending into the upper tube body is provided with a piston matched with the inner wall of the upper tube body, the lower tube body is provided with a lower connecting structure for connecting the packer below the upper tube body, the piston is located above the inner ring platform so that a pumping cavity is formed between the piston and the inner ring platform when the upper tube body moves downward relative to the piston, the lower tube body is provided with an upper check valve structure and a lower check valve structure for liquid to flow upward, and the lower tube body is provided with a connecting hole for connecting the inner cavity of the lower tube body with the pumping cavity between the upper check valve structure and the lower check valve structure in the up and down directions.

2. The formation pumping device according to claim 1, characterized in that: The upper check valve structure is arranged on the piston, and the piston has a central hole which can connect the inner cavity of the upper tube body with the inner cavity of the lower tube body. The upper check valve structure includes a blocking body which is movably arranged on the piston and is used to block the central hole.

3. The formation pumping device according to claim 2, characterized in that: The blocking body is a sphere, and a sealing surface which cooperates with the sphere in a sealing manner is arranged on the piston.

4. The formation pumping device according to claim 1, 2 or 3, characterized in that: An upward abutting surface is arranged on the lower tube body below the inner ring platform, and a spring is sleeved outside the lower tube body, the upper end of the spring abuts against the lower end surface of the inner ring platform, and the lower end abuts against the upward abutting surface.

5. The formation pumping device according to claim 4, characterized in that: The lower tube body comprises an inner tube and a lower joint connected to the lower end of the inner tube, and the upward abutting surface is arranged on the lower joint.

6. The formation pumping device according to claim 1, 2 or 3, characterized in that: The lower tube body comprises an inner tube, the upper end of the inner tube passes through the inner ring platform and extends into the upper tube body, and the piston is connected to the inner tube.

7. The formation pumping device according to claim 1, 2 or 3, characterized in that: The upper tube body comprises an outer tube, and a sealing ring is connected to the inner wall of the lower end of the outer tube, and the sealing ring constitutes the inner ring platform.

8. The formation pumping device according to claim 1, 2 or 3, characterized in that: The lower check valve structure comprises a valve seat and a valve ball. The valve seat is arranged on the inner wall of the lower tube body, and a matching surface for sealing with the valve ball is arranged on the valve seat.

9. The formation pumping device according to claim 1, 2 or 3, characterized in that: The upper connection structure is an upper joint arranged at the upper end of the upper tube body.

10. The formation pumping device according to claim 1, 2 or 3, characterized in that: The lower connecting structure is located above the lower check valve structure.

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