Feedback type active cleaning device for sand filter tube

Abstract

The present invention discloses a feedback type active cleaning device for sand filter tubes, wherein a piston short circuit and an upstream movable valve body are connected to the upper part of an oil pumping piston, the lower part of the oil pumping piston is connected to the downstream movable valve body and a connecting sleeve, the lower part of the connecting sleeve is connected to a connecting rod, the connecting rod passes through a connecting rod sealing sleeve and can slide in the connecting rod sealing sleeve, and the lower part of the connecting rod is connected to an expanding piston; the oil pumping piston is arranged in an oil pump barrel. The present invention causes the sand filter tube to generate micro-vibrations through positive and negative pressure fluctuations and impacts of feedback liquid, and at the same time, the positive strong impact flow has a real-time unblocking effect on the mechanical blockages on its outer wall, keeps its penetration ability from being damaged, is beneficial to the normal production of the oil well, and can achieve real-time and continuous removal of blockages on the sand filter tube during the production process of the oil well, so as to maintain or even restore the penetration ability of the sand filter tube, thereby ensuring the long-term production capacity of the oil well.

Description

Technical Field

[0001] The invention relates to the technical field of sandstone oil reservoir rod pump lifting, sand filtering and unblocking of sand filter pipes, in particular to a feedback type sand filter pipe active cleaning device. Background Art

[0002] At present, one of the main contradictions in the development of sandstone reservoirs is the uninterrupted sand production in the oil layer. The sand production in the oil layer not only reduces the production time of the oil well and affects the oil well production, but also increases the production cost of the oil well and damages the oilfield production facilities. In order to solve the development contradiction of sand production in the oil layer, oil workers have developed a variety of process methods such as mechanical sand control and chemical sand control. Among them, most oil wells in mechanical sand control use the method of filtering sand with a sand filter pipe under the oil pump, which does have a certain effect. However, the effect of this method is good in the initial stage of use. After a period of sand filtering, the oil well production is significantly reduced. After research, it was found that the sand filter pipe was blocked and had poor permeability, which affected the well fluid from entering the tail pipe under the pump, thereby affecting the production capacity of the oil well.

[0003] In the prior art, the only way to deal with a clogged sand filter tube is to remove the pump and the sand filter structure and replace them. However, this operation not only affects the oil well production but also increases the production cost of the oil well. Frequent operation will also damage the oil layer. At present, there is no feasible technical solution to the blockage of the sand filter tube under the pump except for passively optimizing the pore structure of the filter sand. However, optimizing the pore structure of the filter sand has limited effect and cannot fundamentally change this technical deficiency. In view of this, in-depth research was conducted on the above-mentioned problems, which led to the present case. Summary of the invention

[0004] The purpose of the present invention is to solve the above-mentioned problems. A feedback type active cleaning device for filter sand pipes is designed to solve the current solution to the blockage of filter sand pipes under the pump. There is no feasible technical solution except passively optimizing the pore structure of the filter sand. However, the effect of optimizing the pore structure of the filter sand is limited and cannot fundamentally change the problem of this technical deficiency.

[0005] The technical scheme of the present invention for achieving the above-mentioned purpose is as follows: a feedback type active cleaning device for sand filter tube, wherein a piston short circuit and an upstream movable valve body are connected to the upper part of the pumping piston, and the lower part of the pumping piston is connected to the downstream movable valve body and a connecting sleeve, an upper valve ball and an upper valve seat are installed in the upstream movable valve body, and a lower valve ball and a lower valve seat are installed in the downstream movable valve body, the lower part of the connecting sleeve is connected to a connecting rod, the connecting rod passes through a connecting rod sealing sleeve and can slide in the connecting rod sealing sleeve, and the lower part of the connecting rod is connected to an expanding piston; the pumping piston is arranged in a pump barrel;

[0006] The lower part of the oil pump barrel is connected to the annular fixed valve through a fixed valve short circuit. The fixed valve short circuit is set as a stepped hole and an internal thread is set in the small diameter section to connect the oil pump barrel. The fixed valve short circuit is set with an external thread outside to connect the fixed valve outer sleeve. A concentric valve seat inner sleeve and valve seat outer sleeve are installed in the fixed valve outer sleeve. An annular valve ball is installed at one end of the annular space of the valve seat inner sleeve and the valve seat outer sleeve.

[0007] The inner end surface of the valve seat outer sleeve and the outer end surface of the valve seat inner sleeve are both provided with the same smooth chamfer, the inner end surface of the valve seat outer sleeve and the valve seat inner sleeve are axially fixed by a valve seat bridging sleeve, and radially fixed by a fixed valve outer sleeve and a fixed valve inner sleeve, and form an annular valve seat sealing structure, the valve seat bridging sleeve is provided with an inner through hole, and the inner through hole is provided with a thread and is connected to the fixed valve inner sleeve, the outer wall of the valve seat bridging sleeve is provided with an external thread and is connected to the fixed valve outer sleeve, and a plurality of axial through holes are provided on the valve seat bridging sleeve, partitions are provided between the axial through holes, and the lower end of the fixed valve outer sleeve is connected with a fixed valve lower joint.

[0008] The outer wall surface of the above-mentioned fixed valve inner sleeve is arranged in a stepped shape, which includes the first step, the second step and the third step from top to bottom. The first step is matched with the clearance of the through hole in the annular valve ball, the second step is matched with the clearance of the through hole in the valve seat inner sleeve, and the axial position of the valve seat inner sleeve is limited by the step. The second step is provided with a section of external thread, and the third step is provided with a section of internal thread. The external thread of the second step is connected to the valve seat bridging sleeve, and the internal thread of the third step is connected to the connecting rod sealing sleeve. The inner hole of the fixed valve inner sleeve is arranged as a stepped hole, the upper diameter expansion step of the stepped hole limits the downward position of the connecting sleeve, and the lower expansion hole is provided with an internal thread connected to the connecting rod sealing sleeve.

[0009] The above-mentioned annular valve ball can slide up and down in the fixed valve sleeve. The upper inner and outer wall end faces of the annular valve ball are arranged to be streamlined and the lower inner and outer wall end faces are arranged to be smooth chamfers with a certain angle. The smooth chamfer on the annular valve ball and the smooth chamfers on the inner end face of the valve seat sleeve and the outer end face of the valve seat inner sleeve are matched and sealed with each other.

[0010] A plurality of axial liquid-passing grooves are arranged on the inner and outer walls of the annular valve ball. The liquid-passing grooves are arranged as inclined grooves at a certain angle to the axis. The incoming liquid generates a certain axial force through the inclined grooves, causing the valve ball to rotate, thereby extending the service life of the valve ball.

[0011] The above-mentioned expanding piston includes an expanding piston locking ring, a plurality of expanding piston blocks, a return spring and an expanding piston valve pressure cap. A radial through groove is arranged in the expanding piston block, and small-diameter circular steps are arranged at both ends. The return spring is installed in the radial through groove. A plurality of the expanding piston blocks form a variable-diameter piston assembly with a variable diameter, and the upper end is installed in the expanding piston locking ring, and the lower end is installed in the expanding piston valve pressure cap.

[0012] The expanded piston valve seat, expanded piston valve ball and liquid inlet reset spring are installed in the expanded piston valve bonnet. The liquid inlet reset spring presses on the expanded piston valve ball, so that the expanded piston valve ball is in a liquid inlet state during the upward stroke.

[0013] The inner and outer parts of the aforementioned enlarged diameter piston blocks form a concentric circle to form a circular tube body, namely a variable diameter piston assembly.

[0014] The above-mentioned expanded diameter piston valve pressure cap is arranged in a stepped shape, which is divided into four sections from top to bottom. The first section is provided with an internal thread, the second section is necked, and the third section is expanded. A number of axial liquid inlet grooves are arranged in the second section to communicate with the third section, and a number of axial through holes are arranged in the fourth section, with isolation sections left between the axial through holes.

[0015] The feedback type sand filter tube active cleaning device manufactured by the technical solution of the present invention is

[0016] The upward stroke of the pumping piston drives the connecting rod, which further drives the expanding piston upward. Under the action of the liquid inlet return spring, the expanding piston valve ball remains away from the valve seat of the expanding piston, so that the liquid at the bottom of the expanding piston enters the pump barrel through the annular valve. When the inlet liquid passes through the inclined groove of the annular fixed valve, an axial force is generated, causing the annular valve ball to rotate to a certain extent, which can extend the life of the valve body;

[0017] The downward stroke of the oil pump piston drives the connecting rod, which further drives the expansion piston downward. The expansion piston valve ball overcomes the axial force of the liquid inlet reset spring under the action of hydraulic force and sits on the expansion piston valve seat, closing the expansion piston inlet passage. The expansion piston pushes the liquid to increase the pressure in the sand filter tube, forming a pressure difference between the inside and outside of the sand filter tube. Under the action of the pressure difference, the contaminants composed of mechanical impurities, paraffin, and colloid asphalt on the outer wall of the sand filter tube are removed, so that the sand filter tube maintains or restores its permeability, thereby making the fluid channel in and out of the screen tube unobstructed;

[0018] The present invention causes the sand filter tube to generate micro-vibration through its positive and negative pressure fluctuations and feedback liquid impact. At the same time, the positive strong impact flow has a real-time unblocking effect on the mechanical blockages on its outer wall, keeping its permeability intact, which is beneficial to the normal production of the oil well. During the production of the oil well, the blockages on the sand filter tube can be cleared in real time and continuously, so as to maintain or even restore the permeability of the sand filter tube, thereby ensuring the long-term production capacity of the oil well.

[0019] At present, more than 90% of my country's oil fields are sandstone reservoirs. Sand production from oil wells is a common feature of sandstone reservoirs, especially shallowly buried oil wells. Due to cost constraints, the current mechanical sand control mainly uses the sand-blocking process with a sand filter pipe under the pump. Therefore, the present invention has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a front view schematic diagram of the present invention.

[0021] Figure 2 For the present invention Figure 1 Schematic diagram of the cross-sectional structure at the AA position.

[0022] Figure 3 For the present invention Figure 1 Schematic diagram of the cross-sectional structure of the BB position.

[0023] Figure 4 For the present invention Figure 1 Schematic diagram of the cross-sectional structure of the CC position.

[0024] In the figure: 1-oil pump barrel; 2-upper movable valve body; 3-upper valve ball; 4-upper valve seat; 5-piston short circuit; 6-oil pump piston; 7-downstream movable valve body; 8-lower valve ball; 9-lower valve seat; 10-connecting sleeve; 11-fixed valve short circuit; 12-fixed valve outer sleeve; 13-annular valve ball; 14-valve seat outer sleeve; 15-valve seat inner sleeve; 16-valve seat bridge sleeve; 17-fixed valve inner sleeve; 18-connecting rod; 19-fixed valve lower joint; 20-connecting rod sealing sleeve; 21-expanded piston lock ring; 22-expanded piston block; 23-reset spring; 24-liquid inlet reset spring; 25-expanded piston valve seat; 26-expanded piston valve ball; 27-expanded piston valve pressure cap. DETAILED DESCRIPTION

[0025] The present invention will be described in detail below in conjunction with the accompanying drawings. Figure 1-4 As shown, the components in this case are connected in sequence by those skilled in the art. The specific connection and operation sequence should refer to the following working principle. The detailed connection means are well-known technologies in the art. The following mainly introduces the working principle and process.

[0026] Embodiment: By the specification attached Figure 1-4It can be seen that in this scheme, the piston short circuit 5 and the upstream movable valve body 2 are connected at the upper part of the pumping piston 6, and the lower part of the pumping piston 6 is connected to the downstream movable valve body 7 and the connecting sleeve 10. The upper valve ball 3 and the upper valve seat 4 are installed in the upstream movable valve body 2, and the lower valve ball 8 and the lower valve seat 9 are installed in the downstream movable valve body 7. The lower part of the connecting sleeve 10 is connected to the connecting rod 18, and the connecting rod 18 passes through the connecting rod sealing sleeve 20 and can slide in the connecting rod sealing sleeve 20. The lower part of the connecting rod 18 is connected to the enlarged piston; the pumping piston 6 is arranged in the pump barrel 1; the lower part of the pump barrel 1 is connected to the fixed valve short circuit 11 is connected with the annular fixed valve, the fixed valve short-circuit 11 is set as a stepped hole and an internal thread is set in the small diameter section to connect the oil pump barrel 1, the fixed valve short-circuit 11 is provided with an external thread outside to connect the fixed valve outer sleeve 12, the fixed valve outer sleeve 12 is installed with a concentric valve seat inner sleeve 15 and a valve seat outer sleeve 14, and an annular valve ball 13 is installed at one end of the annular space of the valve seat inner sleeve 15 and the valve seat outer sleeve 14; the inner end surface of the valve seat outer sleeve 14 and the outer end surface of the valve seat inner sleeve 15 are all provided with the same smooth chamfer, and the inner end surface of the valve seat outer sleeve 14 and the valve seat inner sleeve 15 are provided with the same smooth chamfer. The axial direction is fixed by the valve seat bridge sleeve 16, and the radial direction is fixed by the fixed valve outer sleeve 12 and the fixed valve inner sleeve 17, and an annular valve seat sealing structure is formed. The valve seat bridge sleeve 16 is provided with an inner through hole, and the inner through hole is provided with a thread and connected to the fixed valve inner sleeve 17. The outer wall of the valve seat bridge sleeve 16 is provided with an external thread and connected to the fixed valve outer sleeve 12, and the valve seat bridge sleeve 16 is provided with a plurality of axial through holes, and partitions are provided between the axial through holes. The lower end of the fixed valve outer sleeve 12 is connected to the fixed valve lower joint 19, and the upper stroke of the pumping piston 6 drives the connecting rod 18 , further drives the expansion piston upward, so that the liquid at the bottom of the expansion piston enters the pump barrel 1 through the annular fixed valve, and the downward stroke of the oil pump piston 6 drives the connecting rod 18, which further drives the expansion piston downward, so that the expansion piston liquid inlet channel is closed, and the expansion piston further pushes the liquid to increase the pressure in the sand filter tube, forming a pressure difference between the inside and outside of the sand filter tube. Under the action of the pressure difference, the contaminants composed of mechanical impurities, paraffin, and colloid asphalt on the outer wall of the sand filter tube are removed, so that the sand filter tube maintains or restores its permeability, thereby making the fluid channel in and out of the screen tube unobstructed.

[0027] In the specific implementation process, the outer wall surface of the fixed valve inner sleeve 17 is set to be stepped, and from top to bottom are respectively the first step, the second step and the third step, the first step is matched with the clearance of the through hole in the annular valve ball 13, the second step is matched with the clearance of the through hole in the valve seat inner sleeve 15, and the axial position of the valve seat inner sleeve 15 is limited by the step, the second step is provided with a section of external thread, the third step is provided with a section of internal thread, the external thread of the second step is connected to the valve seat bridge sleeve 16, the internal thread of the third step is connected to the connecting rod sealing sleeve 20, the inner hole of the fixed valve inner sleeve 17 is set as a stepped hole, and the upper diameter expansion step of the stepped hole limits the connection sleeve 10 An internal threaded connecting rod sealing sleeve 20 is arranged at the downward position and the lower expanded hole, wherein the annular valve ball 13 can slide up and down in the fixed valve outer sleeve 12, the upper inner and outer wall end faces of the annular valve ball 13 are arranged to be streamlined and the lower inner and outer wall end faces are arranged to be smooth chamfers at a certain angle, the smooth chamfers on the annular valve ball 13 and the smooth chamfers on the inner end face of the valve seat outer sleeve 14 and the outer end face of the valve seat inner sleeve 15 are matched and sealed with each other, and a plurality of axial liquid passing grooves are arranged on the inner and outer walls of the annular valve ball 13, and the liquid passing grooves are arranged to be inclined grooves at a certain angle to the axis, and the incoming liquid generates a certain axial force through the inclined grooves, so that the valve ball rotates, thereby extending the service life of the valve ball.

[0028] In the specific implementation process, the above-mentioned expanding piston includes an expanding piston locking ring 21, a plurality of expanding piston blocks 22, a return spring 23 and an expanding piston valve pressing cap 27. A radial through groove is arranged in the expanding piston block 22, and small-diameter circular steps are arranged at both ends. The return spring 23 is installed in the radial through groove. The plurality of expanding piston blocks 22 form a variable-diameter piston assembly with a variable diameter, and the upper end is installed in the expanding piston locking ring 21, and the lower end is installed in the expanding piston valve pressing cap 27. The expanding piston valve seat 25, the expanding piston valve ball 26, and the liquid inlet return spring 24 are installed in the expanding piston valve pressing cap 27. The liquid inlet return spring 24 presses on the expanding piston. On the piston valve ball 26, during the upward stroke, the expanded piston valve ball 26 is in a liquid-intake state. The inside and outside of the above-mentioned expanded piston blocks 22 form a concentric circle to form a circular tube body, that is, a variable-diameter piston assembly, wherein the expanded piston valve pressure cap 27 is arranged in a stepped shape, and is divided into four sections from top to bottom. The first section is provided with an internal thread, the second section is necked, and the third section is expanded. A plurality of axial liquid-intake grooves are arranged in the second section to communicate with the third section, and a plurality of axial through holes are arranged in the fourth section, and isolation sections are left between the axial through holes. The upward stroke of the pumping piston 6 drives the connecting rod 18, which further drives the expanded piston upward, and the expanded piston valve ball is further in the liquid-intake reset spring. Under the action of the spring, the expanded piston valve seat is kept away, so that the liquid at the bottom of the expanded piston enters the pump barrel 1 through the annular valve. When the incoming liquid passes through the inclined groove of the annular fixed valve, an axial force is generated, which causes the annular valve ball to rotate a certain amount, thereby extending the life of the valve body; the downward stroke of the oil pump piston drives the connecting rod, which further drives the expanded piston downward. Further, the expanded piston valve ball 26 overcomes the axial force of the inlet return spring 24 under the action of hydraulic force, sits on the expanded piston valve seat 25, and closes the expanded piston inlet passage. Further, the expanded piston pushes the liquid to increase the pressure in the sand filter tube, forming a pressure difference between the inside and outside of the sand filter tube. The contaminants composed of mechanical impurities, paraffin and colloid asphaltene on the outer wall of the sand filter tube are removed, so that the sand filter tube maintains or restores its permeability, thereby making the fluid channel in and out of the screen tube unblocked; the present invention causes the sand filter tube to produce micro-vibration through its positive and negative pressure fluctuations and feedback liquid impact, and at the same time, the positive strong impact flow has a real-time unblocking effect on the mechanical blockages on its outer wall, keeping its permeability intact, which is beneficial to the normal production of the oil well, and can achieve real-time and continuous removal of blockages on the sand filter tube during the production process of the oil well, so as to maintain or even restore the permeability of the sand filter tube, thereby ensuring the long-term production capacity of the oil well.

[0029] The above technical solutions only reflect the preferred technical solutions of the technical solutions of the present invention. Some changes that may be made to certain parts thereof by technicians in this technical field all reflect the principles of the present invention and fall within the protection scope of the present invention.

Claims

1. A feedback type sand filter tube active cleaning device, characterized in that: The upper part of the pumping piston (6) is connected to a piston short circuit (5) and an upstream movable valve body (2); the lower part of the pumping piston (6) is connected to a downstream movable valve body (7) and a connecting sleeve (10); an upper valve ball (3) and an upper valve seat (4) are installed in the upstream movable valve body (2); a lower valve ball (8) and a lower valve seat (9) are installed in the downstream movable valve body (7); the lower part of the connecting sleeve (10) is connected to a connecting rod (18); the connecting rod (18) passes through a connecting rod sealing sleeve (20) and can slide in the connecting rod sealing sleeve (20); the lower part of the connecting rod (18) is connected to an expanding piston; the pumping piston (6) is arranged in an oil pump barrel (1); The lower part of the oil pump barrel (1) is connected to the annular fixed valve through a fixed valve short circuit (11); the fixed valve short circuit (11) is arranged as a stepped hole and an internal thread is arranged at the small diameter section for connecting to the oil pump barrel (1); the fixed valve short circuit (11) is arranged with an external thread outside for connecting to the fixed valve outer sleeve (12); a concentric valve seat inner sleeve (15) and a valve seat outer sleeve (14) are installed in the fixed valve outer sleeve (12); an annular valve ball (13) is installed at one end of the annular space of the valve seat inner sleeve (15) and the valve seat outer sleeve (14); The inner end surface of the valve seat outer sleeve (14) and the outer end surface of the valve seat inner sleeve (15) are both provided with the same smooth chamfer. The inner end surface of the valve seat outer sleeve (14) and the valve seat inner sleeve (15) are axially fixed by a valve seat bridge sleeve (16) and radially fixed by a fixed valve outer sleeve (12) and a fixed valve inner sleeve (17), and form an annular valve seat sealing structure. The valve seat bridge sleeve (16) is provided with an inner through hole, and a thread is provided in the inner through hole and connected to the fixed valve inner sleeve (17). The outer wall of the valve seat bridge sleeve (16) is provided with an external thread and connected to the fixed valve outer sleeve (12). The valve seat bridge sleeve (16) is provided with a plurality of axial through holes, and partitions are provided between the axial through holes. The lower end of the fixed valve outer sleeve (12) is connected to a fixed valve lower joint (19); The annular valve ball (13) can slide up and down in the fixed valve sleeve (12), the upper inner and outer wall end faces of the annular valve ball (13) are set to be streamlined, and the lower inner and outer wall end faces are set to be smooth chamfers with a certain angle, and the smooth chamfers on the annular valve ball (13) are matched and sealed with the smooth chamfers of the inner end face of the valve seat sleeve (14) and the outer end face of the valve seat inner sleeve (15); The expanding piston comprises an expanding piston lock ring (21), a plurality of expanding piston blocks (22), a return spring (23) and an expanding piston valve cap (27); a radial through groove is arranged in the expanding piston block (22) and small-diameter circular steps are arranged at both ends; the return spring (23) is installed in the radial through groove; a plurality of expanding piston blocks (22) form a variable-diameter piston assembly, and the upper end is installed in the expanding piston lock ring (21) and the lower end is installed in the expanding piston valve cap (27).

2. A feedback type sand filter tube active cleaning device according to claim 1, characterized in that: The outer wall surface of the fixed valve inner sleeve (17) is arranged in a stepped shape, which comprises the first step, the second step and the third step from top to bottom. The first step is in clearance with the inner through hole of the annular valve ball (13), the second step is in clearance with the inner through hole of the valve seat inner sleeve (15), and the axial position of the valve seat inner sleeve (15) is limited by the step. The second step is provided with a section of external thread, and the third step is provided with a section of internal thread. The external thread of the second step is connected to the valve seat bridge sleeve (16), and the internal thread of the third step is connected to the connecting rod sealing sleeve (20). The inner hole of the fixed valve inner sleeve (17) is arranged as a stepped hole, the upper diameter expansion step of the stepped hole limits the downward position of the connecting sleeve (10), and the lower expansion hole is provided with an internal thread connected to the connecting rod sealing sleeve (20).

3. The feedback type sand filter tube active cleaning device according to claim 1, characterized in that: A plurality of axial liquid-passing grooves are arranged on the inner and outer walls of the annular valve ball (13), and the liquid-passing grooves are arranged as inclined grooves that form a certain angle with the axis.

4. The feedback type active cleaning device for sand filter tube according to claim 1, characterized in that: The expanded piston valve seat (25), the expanded piston valve ball (26) and the liquid inlet reset spring (24) are installed in the expanded piston valve pressing cap (27). The liquid inlet reset spring (24) presses on the expanded piston valve ball (26) to put the expanded piston valve ball (26) in a liquid inlet state during the upward stroke.

5. A feedback type sand filter tube active cleaning device according to claim 4, characterized in that: A plurality of the enlarged diameter piston blocks (22) are concentrically circled inside and outside to form a circular tube body, namely a variable diameter piston assembly.

6. A feedback type sand filter tube active cleaning device according to claim 5, characterized in that: The expanded piston valve bonnet (27) is arranged in a stepped shape and is divided into four sections from top to bottom. The first section is provided with an internal thread, the second section is necked, and the third section is expanded. The second section is provided with a plurality of axial liquid inlet grooves connected to the third section, and the fourth section is provided with a plurality of axial through holes, with isolation sections left between the axial through holes.

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