Positive circulation constant pressure control valve

Abstract

The invention discloses a positive circulation constant pressure control valve which comprises a central pipe, one end of the central pipe is fixedly connected with an upper positioning sleeve, the other end of the upper positioning sleeve is fixedly connected with an upper connector, the other end of the central pipe is fixedly connected with a lower positioning sleeve, and the other end of the lower positioning sleeve is fixedly connected with a lower connector. A well washing piston is fixedly embedded in the inner wall of the upper positioning sleeve, a through hole is formed in the inner wall of the well washing piston, an annular groove is formed in the inner wall of the well washing piston, an annular cavity is formed in the inner wall of the well washing piston, and an annular rack is slidably connected to the inner wall of the annular cavity. By arranging the piezoelectric sensor, the conductive spring, the triangular plate and other structures, flushing fluid enters the center pipe through the oil pipe, and when the flushing pressure reaches a set value, the control valve is opened, so that the flushing fluid circulates through the through hole and can return to the ground through the discharge hole, the using amount of the flushing fluid is small, and pollution to an oil layer is small.

Description

Technical Field

[0001] The invention relates to the technical field of control valves, and in particular to a positive cycle constant pressure control valve. Background Art

[0002] Oil well wax prevention and wax removal is to prevent wax accumulation on the wall of the oil pipe and near the bottom of the well to ensure the normal production of the oil well. Crude oil contains different amounts of paraffin wax, which is generally in a dissolved state under the conditions of the oil layer. When crude oil rises from the bottom of the well and flows through the oil pipe, the temperature and pressure gradually decrease, and the wax gradually precipitates, gathers, and accumulates on the pipe wall, which is called oil well wax deposition. It reduces the inner diameter of the oil pipe, affects the production capacity of the well, and in severe cases, causes the oil well to stop production.

[0003] The wax deposition in mechanical oil wells in oil fields will increase energy consumption and even affect the operating efficiency. Regular hot washing and wax removal are usually adopted. At present, conventional hot washing and wax removal often adopts reverse circulation. Backwashing is the process in which the well washing fluid enters the wellbore from the casing and returns to the ground through the oil pump and the oil pipe. This well washing method has low thermal efficiency and large liquid volume. The well washing fluid easily enters the formation, causing great damage to the oil layer. The period for the oil well to resume normal oil production is long, which affects the oil well production.

[0004] For this purpose, we designed a positive cycle constant pressure control valve. Summary of the invention

[0005] The purpose of the present invention is to solve the problems existing in the prior art and to propose a positive cycle constant pressure control valve.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: A positive cycle constant pressure control valve comprises a center tube, one end of the center tube is fixedly connected to an upper positioning sleeve, the other end of the upper positioning sleeve is fixedly connected to an upper joint, the other end of the center tube is fixedly connected to a lower positioning sleeve, and the other end of the lower positioning sleeve is fixedly connected to a lower joint; a well-washing piston is embedded and fixed on the inner wall of the upper positioning sleeve, a through hole is provided on the inner wall of the well-washing piston, an annular groove is provided on the inner wall of the well-washing piston, an annular cavity is provided on the inner wall of the well-washing piston, an annular rack is slidably connected to the inner wall of the annular cavity, a plurality of rotating shafts are evenly distributed and rotatably connected to the inner wall of the annular cavity, and each of the side walls of the rotating shaft is fixedly connected There is a gear, and a plurality of sliding cavities are evenly distributed on the inner wall of the annular cavity, and each of the sliding cavity inner walls is sealed and slidably connected with a slide plate, and each of the slide inner walls is fixedly connected with a rack, and the rack passes through and is slidably connected to the inner wall of the annular cavity, and the end of the rack away from the slide plate is fixedly connected with a triangular plate, and an arc-shaped cavity is opened on the inner wall of the well-washing piston, and a sliding plug is sealed and slidably connected to the inner wall of the arc-shaped cavity, and the arc-shaped cavity is fixedly connected to the sliding cavity through a connecting pipe, and a conductive spring is fixedly connected to the side wall of the sliding plug, and the other end of the conductive spring is fixedly connected to the inner wall of the arc-shaped cavity, and a trigger mechanism for powering the conductive spring is provided inside the lower positioning sleeve.

[0007] Furthermore, the trigger mechanism includes a piezoelectric sensor fixedly connected to the inner wall of the lower positioning sleeve, a constant pressure piston is slidably connected to the inside of the central tube, a pressure block is fixedly connected to the side wall of the constant pressure piston, a first spring is fixedly connected to the side wall of the lower positioning sleeve, the other end of the first spring is fixedly connected to the constant pressure piston, and the piezoelectric sensor is electrically connected to the conductive spring.

[0008] Furthermore, a liquid storage cavity is provided on the inner wall of the well-washing piston, and the liquid storage cavity is filled with a cleaning agent.

[0009] Furthermore, a pumping cavity is provided on the inner wall of the well-washing piston, a piston plate is sealingly and slidably connected inside the pumping cavity, and an arc rod is fixedly connected to the other end of the piston plate.

[0010] Furthermore, one end of the arc rod away from the piston plate passes through the inner wall of the pumping chamber and is fixedly connected to the side wall of the sliding plug. The inner wall of the pumping chamber is fixedly connected to the liquid storage chamber through a one-way liquid inlet pipe.

[0011] Furthermore, a plurality of spray holes are formed on the inner wall of the central tube, and the spray holes are fixedly connected to the liquid extraction cavity through a one-way liquid outlet pipe.

[0012] Furthermore, a rectangular cavity is opened on the inner wall of the upper positioning sleeve, an electric push rod is installed on the inner wall of the rectangular cavity, a connecting rod is fixedly connected to the movable end of the electric push rod, and an end of the connecting rod away from the electric push rod passes through the inner wall of the rectangular cavity and is fixedly connected to a sealing sleeve.

[0013] Furthermore, an inlet hole is provided on the inner wall of the central tube, an outlet hole is provided on the inner wall of the upper positioning sleeve, the sealing sleeve and the side wall of the central tube are fitted and slid in a sealed manner, and the triangular plate and the inner wall of the arc groove are fitted and slid in a sealed manner.

[0014] Furthermore, each of the gears is meshed and connected with an annular rack, and each of the gears is meshed and connected with a corresponding rack.

[0015] The present invention has the following advantages: 1. By setting up structures such as piezoelectric sensors, conductive springs and triangular plates, the well washing fluid enters the center pipe through the oil pipe. When the well washing pressure reaches the set value, the control valve opens, allowing the well washing fluid to flow through the through hole, and the well washing fluid can return to the ground through the discharge hole. The positive circulation has higher thermal efficiency than the reverse circulation well washing, uses less well washing fluid, and has less pollution to the oil layer. It can effectively reduce the drainage time after well washing, and the well washing quality is good; 2. By setting up structures such as the pumping chamber, the arc rod and the spray hole, in the above process, the piston plate can also squeeze the cleaning agent inside the pumping chamber to the multiple spray holes for spraying, thereby cleaning the inside of the central tube of the control valve, avoiding impurities in the well washing fluid from remaining inside the central tube and affecting the use of the control valve.

[0016] 3. The present invention relates to a positive circulation constant pressure control valve for hot washing and paraffin removal of oil wells, which is connected to an oil pipe at a predetermined depth of a production string. A positive circulation method is adopted during hot washing and paraffin removal, and the well washing fluid enters through the oil pipe. When the well washing pressure reaches a set value, the positive circulation constant pressure control valve opens, and the well washing fluid returns to the ground through the oil casing. The positive circulation has higher thermal efficiency than the reverse circulation well washing, uses less well washing fluid, and has less pollution to the oil layer. It can effectively reduce the drainage time after well washing, and the well washing quality is good. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a structural schematic diagram of a positive cycle constant pressure control valve proposed by the present invention; Figure 2 This is a schematic diagram of the structure inside the well-washing piston in a positive cycle constant pressure control valve proposed by the present invention; Figure 3 for Figure 2 A magnified schematic diagram of the structure of part A.

[0018] In the figure: 1 center tube, 2 upper positioning sleeve, 3 upper joint, 4 lower positioning sleeve, 5 lower joint, 6 piezoelectric sensor, 7 constant pressure piston, 8 well washing piston, 9 annular cavity, 10 annular groove, 11 through hole, 12 annular rack, 13 rotating shaft, 14 gear, 15 sliding cavity, 16 slide plate, 17 rack, 18 triangular plate, 19 rectangular cavity, 20 electric push rod, 21 arc cavity, 22 sealing sleeve, 23 entry hole, 24 pressure block, 25 first spring, 27 discharge hole, 29 sliding plug, 30 conductive spring, 32 pumping cavity, 33 piston plate, 34 arc rod, 35 liquid storage cavity, 36 spray hole. DETAILED DESCRIPTION

[0019] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific implementation disclosed below.

[0020] Reference Figure 1-3A positive cycle constant pressure control valve comprises a central tube 1, one end of the central tube 1 is fixedly connected with an upper positioning sleeve 2, the other end of the upper positioning sleeve 2 is fixedly connected with an upper joint 3, the other end of the central tube 1 is fixedly connected with a lower positioning sleeve 4, and the other end of the lower positioning sleeve 4 is fixedly connected with a lower joint 5; a well-washing piston 8 is embedded and fixed on the inner wall of the upper positioning sleeve 2, a through hole 11 is opened on the inner wall of the well-washing piston 8, an annular groove 10 is opened on the inner wall of the well-washing piston 8, an annular cavity 9 is opened on the inner wall of the well-washing piston 8, an annular rack 12 is slidably connected to the inner wall of the annular cavity 9, a plurality of rotating shafts 13 are evenly distributed and rotatably connected to the inner wall of the annular cavity 9, each of the side walls of the rotating shaft 13 is fixedly connected with a gear 14, and a plurality of sliding cavities are evenly distributed on the inner wall of the annular cavity 9 15, each sliding cavity 15 inner wall is sealed and slidably connected with a slide plate 16, each slide plate 16 inner wall is fixedly connected with a rack 17, the rack 17 penetrates and is slidably connected to the inner wall of the annular cavity 9, the end of the rack 17 away from the slide plate 16 is fixedly connected with a triangular plate 18, after a plurality of triangular plates 18 are in contact with each other, they can form a cover on the through hole 11, an arc cavity 21 is opened on the inner wall of the well washing piston 8, a sliding plug 29 is sealed and slidably connected with the inner wall of the arc cavity 21, the arc cavity 21 is fixedly connected with the sliding cavity 15 through a connecting pipe, a conductive spring 30 is fixedly connected to the side wall of the sliding plug 29, the other end of the conductive spring 30 is fixedly connected to the inner wall of the arc cavity 21, and a trigger mechanism for supplying power to the conductive spring 30 is provided inside the lower positioning sleeve 4.

[0021] The trigger mechanism includes a piezoelectric sensor 6 fixedly connected to the inner wall of the lower positioning sleeve 4. The piezoelectric sensor 6 is a prior art. A constant pressure piston 7 is slidably connected inside the central tube 1. A pressure block 24 is fixedly connected to the side wall of the constant pressure piston 7. A first spring 25 is fixedly connected to the side wall of the lower positioning sleeve 4. The other end of the first spring 25 is fixedly connected to the constant pressure piston 7. The piezoelectric sensor 6 is electrically connected to the conductive spring 30, and a resistor is provided in the circuit formed by the piezoelectric sensor 6 and the conductive spring 30.

[0022] A liquid storage chamber 35 is provided on the inner wall of the well-washing piston 8. The liquid storage chamber 35 is filled with a cleaning agent. A liquid filling valve cover is provided on the inner wall of the liquid storage chamber 35 to facilitate the addition of the cleaning agent.

[0023] A pumping cavity 32 is formed on the inner wall of the well-washing piston 8 , a piston plate 33 is sealingly and slidably connected inside the pumping cavity 32 , and an arc-shaped rod 34 is fixedly connected to the other end of the piston plate 33 .

[0024] The end of the arc rod 34 away from the piston plate 33 passes through the inner wall of the pumping chamber 32 and is fixedly connected to the side wall of the sliding plug 29. The inner wall of the pumping chamber 32 is fixedly connected to the liquid storage chamber 35 through a one-way liquid inlet pipe. The one-way liquid inlet pipe only allows the cleaning agent inside the liquid storage chamber 35 to be pumped into the pumping chamber 32.

[0025] The inner wall of the central tube 1 is provided with a plurality of spray holes 36 , which are fixedly connected to the liquid extraction chamber 32 via a one-way liquid outlet pipe. The one-way liquid outlet pipe only allows the cleaning agent inside the liquid extraction chamber 32 to be squeezed to the spray holes 36 for spraying.

[0026] A rectangular cavity 19 is formed in the inner wall of the upper positioning sleeve 2. An electric push rod 20 is installed in the inner wall of the rectangular cavity 19. A connecting rod is fixedly connected to the movable end of the electric push rod 20. The end of the connecting rod away from the electric push rod 20 passes through the inner wall of the rectangular cavity 19 and is fixedly connected to a sealing sleeve 22.

[0027] An inlet hole 23 is opened on the inner wall of the center tube 1 , an outlet hole 27 is opened on the inner wall of the upper positioning sleeve 2 , the sealing sleeve 22 and the side wall of the center tube 1 fit and slide in a sealed manner, the triangular plate 18 and the inner wall of the annular groove 10 fit and slide in a sealed manner, and the sealing sleeve 22 covers and seals the inlet hole 23 .

[0028] Each gear 14 is meshed and connected with the annular rack 12 , and each gear 14 is meshed and connected with the corresponding rack 17 . The annular rack 12 and the rack 17 are staggered.

[0029] In the present invention, when using the device, the electric push rod 20 is first turned on, and the movable end of the electric push rod 20 drives the connecting rod to move, and then the connecting rod drives the sealing sleeve 22 away from the entry hole 23, and the well washing fluid enters the center tube 1 through the entry hole 23. Under the injection pressure of the well washing fluid, the constant pressure piston 7 is pushed to slide to the right for a distance, and the constant pressure piston 7 will drive the pressure block 24 to move synchronously until the end of the pressure block 24 away from the constant pressure piston 7 is pressed against the piezoelectric sensor 6. After the piezoelectric sensor 6 is subjected to a certain extrusion force, the piezoelectric effect is applied to the conductive spring 30, and then the conductive spring 30 is energized and contracts. When the conductive spring 30 is energized, it is equivalent to an energized solenoid. Each turn of the spring is equivalent to a circular current, and the current direction in each turn of the spring is the same. According to the mutual attraction between currents in the same direction, each turn of the spring attracts the adjacent springs, so the conductive spring 30 will shrink as a whole, and the conductive spring 30 will drive the sliding plug 29 to slide a certain distance to the left. The sliding cavity 15 is filled with hydraulic oil, so that the sliding plug 29 drives the slide plate 16 to slide a certain distance through the hydraulic oil, and then the slide plate 16 drives the rack 17 to move, and the rack 17 drives the corresponding triangular plate 18 to slide a certain distance away from the through hole 11. At this time, the multiple triangular plates 18 no longer limit the through hole 11, and the well washing fluid flows through the through hole 11 and is then discharged through the discharge hole 27.

[0030] And during the sliding of the sliding plug 29 , the piston plate 33 will be driven to move synchronously through the arc rod 34 , so that the piston plate 33 draws the cleaning agent inside the liquid storage chamber 35 into the liquid extraction chamber 32 . The inner wall of the liquid storage chamber 35 is provided with unidirectional micropores.

[0031] When the well washing operation is stopped, the well washing fluid will no longer flow inside the central pipe 1. When the pressure inside the central tube 1 decreases, the constant-pressure piston 7 will slide a certain distance to the left under the action of the first spring 25, so that the pressure block 24 and the piezoelectric sensor 6 will be separated from each other, and the conductive spring 30 will stop being energized. Then the conductive spring 30 will be de-energized and extend, and then the sliding plug 29 will slide in the reverse sealing state, so that the slide plate 16 drives the corresponding rack 17 to slide in the reverse direction, and the rack 17 drives the corresponding triangular plate 18 to move in the reverse direction, and multiple triangular plates 18 are in contact with each other, thereby covering the through hole 11.

[0032] In the above process, the sliding plug 29 will also drive the piston plate 33 to move synchronously through the arc rod 34, and then the piston plate 33 will squeeze the cleaning agent inside the pumping chamber 32 to the multiple spray holes 36 for spraying, thereby cleaning the inside of the central tube 1 to prevent impurities in the well washing fluid from remaining inside the central tube 1 and affecting the use of the control valve.

[0033] The above are only preferred specific implementation modes of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A positive cycle constant pressure control valve, comprising a central tube (1), characterized in that: One end of the central tube (1) is fixedly connected to an upper positioning sleeve (2), the other end of the upper positioning sleeve (2) is fixedly connected to an upper joint (3), the other end of the central tube (1) is fixedly connected to a lower positioning sleeve (4), the other end of the lower positioning sleeve (4) is fixedly connected to a lower joint (5); A well-washing piston (8) is embedded and fixed on the inner wall of the upper positioning sleeve (2), a through hole (11) is provided on the inner wall of the well-washing piston (8), an annular groove (10) is provided on the inner wall of the well-washing piston (8), an annular cavity (9) is provided on the inner wall of the well-washing piston (8), an annular rack (12) is slidably connected to the inner wall of the annular cavity (9), a plurality of rotating shafts (13) are evenly distributed and rotatably connected to the inner wall of the annular cavity (9), a gear (14) is fixedly connected to the side wall of each rotating shaft (13), a plurality of sliding cavities (15) are evenly distributed on the inner wall of the annular cavity (9), a slide plate (16) is sealingly and slidably connected to the inner wall of each sliding cavity (15), a rack (17) is fixedly connected to the inner wall of each slide plate (16), the rack (17) penetrates and is slidably connected to the inner wall of the annular cavity (9), and a triangular plate (18) is fixedly connected to the end of the rack (17) away from the slide plate (16).

2. A positive cycle constant pressure control valve according to claim 1, characterized in that: The inner wall of the well-washing piston (8) is provided with an arc-shaped cavity (21), the inner wall of the arc-shaped cavity (21) is sealed and slidably connected to a sliding plug (29), the arc-shaped cavity (21) is fixedly connected to the sliding cavity (15) through a connecting pipe, a conductive spring (30) is fixedly connected to the side wall of the sliding plug (29), the other end of the conductive spring (30) is fixedly connected to the inner wall of the arc-shaped cavity (21), a trigger mechanism for supplying power to the conductive spring (30) is provided inside the lower positioning sleeve (4), the trigger mechanism comprises a piezoelectric sensor (6) fixedly connected to the inner wall of the lower positioning sleeve (4), a constant pressure piston (7) is slidably connected inside the central tube (1), a pressure block (24) is fixedly connected to the side wall of the constant pressure piston (7), a first spring (25) is fixedly connected to the side wall of the lower positioning sleeve (4), the other end of the first spring (25) is fixedly connected to the constant pressure piston (7), and the piezoelectric sensor (6) and the conductive spring (30) are electrically connected.

3. A positive cycle constant pressure control valve according to claim 2, characterized in that: The inner wall of the well-cleaning piston (8) is provided with a liquid storage chamber (35), and the liquid storage chamber (35) is filled with a cleaning agent.

4. A positive cycle constant pressure control valve according to claim 3, characterized in that: The inner wall of the well-washing piston (8) is provided with a pumping cavity (32), the interior of the pumping cavity (32) is sealingly and slidably connected to a piston plate (33), and the other end of the piston plate (33) is fixedly connected to an arc-shaped rod (34).

5. A positive cycle constant pressure control valve according to claim 4, characterized in that: One end of the arc-shaped rod (34) away from the piston plate (33) penetrates the inner wall of the pumping chamber (32) and is fixedly connected to the side wall of the sliding plug (29). The inner wall of the pumping chamber (32) is fixedly connected to the liquid storage chamber (35) via a one-way liquid inlet pipe.

6. A positive cycle constant pressure control valve according to claim 5, characterized in that: The inner wall of the central tube (1) is provided with a plurality of spray holes (36), and the spray holes (36) are fixedly connected to the liquid extraction cavity (32) via a one-way liquid outlet tube.

7. A positive cycle constant pressure control valve according to claim 1, characterized in that: The inner wall of the upper positioning sleeve (2) is provided with a rectangular cavity (19), the inner wall of the rectangular cavity (19) is provided with an electric push rod (20), the movable end of the electric push rod (20) is fixedly connected to a connecting rod, and the end of the connecting rod away from the electric push rod (20) passes through the inner wall of the rectangular cavity (19) and is fixedly connected to a sealing sleeve (22).

8. A positive cycle constant pressure control valve according to claim 1, characterized in that: The inner wall of the central tube (1) is provided with an inlet hole (23), the inner wall of the upper positioning sleeve (2) is provided with an outlet hole (27), the sealing sleeve (22) and the side wall of the central tube (1) are fitted and slid in a sealed manner, and the triangular plate (18) and the inner wall of the annular groove (10) are fitted and slid in a sealed manner.

9. A positive cycle constant pressure control valve according to claim 1, characterized in that: Each of the gears (14) is meshedly connected to the annular rack (12), and each of the gears (14) is meshedly connected to the corresponding rack (17).

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