A circulating sand washing liquid reversing device

Abstract

This utility model discloses a circulating sand flushing liquid reversing device, comprising a straight connecting pipe, a coupling, and an outer cylinder connected sequentially from top to bottom. The device is characterized in that a liquid control valve is connected to the upper end of the straight connecting pipe; a liquid outlet is provided on the wall of the outer cylinder; and a liquid outlet sealing device is provided inside the outer cylinder. This utility model can effectively prevent sand from blocking the oil pipe or sand from jamming the sand flushing string during single-pipe reflow; it achieves continuous pump circulation, improving work efficiency; the device has good sealing performance, no leakage, and will not cause wellhead contamination; it can be reused, reducing operating costs and demonstrating significant practical benefits.

Description

Technical Field

[0001] This utility model relates to the field of downhole sand flushing technology, specifically a circulating sand flushing liquid reversing device. Background Technology

[0002] Sand flushing is an important procedure in downhole well workover operations. When sand flushing is performed, the sand flushing pipe at the lower end of the flushing string reaches the sand surface at the bottom of the well. Then, the upper end of the flushing string at the wellhead is connected to the pump truck via a swivel or hose to pump in the sand flushing fluid. The high-speed fluid flow disperses the sand plugs in the wellbore.

[0003] Current sand flushing operations typically involve installing a self-sealing device on top of the wellhead sealing device, with the tubing coupling at the upper end of the flushing string sitting on the upper face of the self-sealing device. After flushing to the depth of a single tubing length, the pump is stopped, and the single flushing tubing length at the upper end of the flushing string is pulled up to the wellhead. Then, another tubing length is connected to the lower end of the single flushing tubing length and lowered into the well to continue flushing. This operation is referred to as "connecting single tubing lengths" on the construction site. This process of connecting single tubing lengths and starting the pump for sand flushing continues until the designed depth is reached. Currently, single-pump trucks are generally used for sand flushing operations. For wells with lost circulation, dual-pump trucks with high displacement or mixed-air water are used for sand flushing. Both sand flushing methods require stopping the pump when transferring single tubing lengths.

[0004] The disadvantages of the above-mentioned sand flushing method are:

[0005] 1. When connecting a single pipe, the pump needs to be stopped. During the unloading and reconnection of the tubing, the pressure imbalance between the tubing and the casing in the well causes oil and water to overflow from the tubing, resulting in wellhead contamination.

[0006] 2. After the pump stops, the sand flushed off the bottom of the well will sink again;

[0007] 3. If the pouring speed of a single pipe is slow, the sand will sink and bury the oil pipe, causing sand blockage, which may lead to a stuck drill accident in severe cases.

[0008] Currently, sand flushing construction costs are high. If the time for flushing a single section is too long, it can lead to sand flushing failure or sand blockage accidents, and subsequent accident handling will significantly increase construction costs.

[0009] Therefore, it is very important to develop a tool that can maintain the continuous circulation of flushing fluid in the well without stopping the pump when using a single flushing tubing.

[0010] Publication (Announcement) No.: CN209244535 discloses a forward and reverse continuous sand flushing reversing device, mainly composed of a reversing self-sealing device, a reversing valve, and a surface reversing valve assembly. The reversing self-sealing device is installed on the upper part of the wellhead blowout preventer. The reversing valve is connected to a single sand flushing tubing string. The surface reversing valve assembly is connected between the reversing valve and the reversing self-sealing device. The upper connector of the reversing valve is threadedly connected to the outer sleeve. An adjusting ring is threadedly installed inside the upper connector. A ball seat and a ball switch are installed inside the upper connector. A steel ball is installed inside the ball seat. A sealing ring, a steel ball, a bearing seat, and a sealing ring are installed on the drive shaft. The drive shaft is threadedly connected to the sliding sleeve switch. A fixing pin is installed on the outer sleeve. The sealing ring is installed on the outer sleeve. The lower connector is threadedly connected to the outer sleeve. This utility model enables continuous sand flushing operation without stopping the pump, effectively preventing accidents such as tubing string jamming during sand flushing and significantly improving sand flushing efficiency. It can also be used in any operation process that requires continuous circulation without stopping the pump.

[0011] The existing technology is not as effective as the present invention in actual use.

[0012] Publication (Announcement) No.: CN111075372A discloses a continuous reverse circulation sand flushing well string and its flushing tools. The continuous reverse circulation sand flushing well string includes tubing, a wellhead casing four-way connector, a single-gate blowout preventer (BOP), and a well-washing tee. The upper end of the wellhead casing four-way connector is connected to the single-gate BOP, and the upper end of the single-gate BOP is connected to the well-washing tee. It also includes a liner, the upper end of which is connected to a liner hanger via threads. The liner hanger is then placed inside the wellhead casing four-way connector and secured with the hanger set screw of the wellhead casing four-way connector. The liner hanger is equipped with a sealing element. Continuous reverse circulation sand flushing tools are connected to each pair of tubing sections. Both the tubing and the continuous reverse circulation sand flushing tools connected to the tubing must pass through the liner from top to bottom. This prior art enables continuous reverse circulation sand flushing operations without stopping the pump after each section, effectively avoiding sand and gravel deposition, improving operational efficiency and safety.

[0013] The existing technology is not as effective as the present invention in actual use.

[0014] Publication (Announcement) No.: CN109577888B discloses a continuous tubing injection device, injection method, and a method for changing tubing without stopping the pump. The continuous tubing injection device, injection method, and method for changing tubing without stopping the pump include a main body base and a main tube sleeved within the main body base; wherein, the main body base is provided with a wellhead connection end and an injection pipeline connection end, and the main body base is connected to the wellhead; the main tube is a circular tube; the main tube has upper and lower connectors for connecting the tubing at both ends, and a fluid inlet hole on the main tube; a sliding opening and closing device is sleeved on the main tube; the sliding opening and closing device includes a sliding sleeve body and a sliding sleeve return spring, and the sliding sleeve body is provided with a sliding sleeve opening and closing stop; the main body base is provided with an elastic steel ring corresponding to the sliding sleeve opening and closing stop; it also includes a hollow one-way valve body, one end of which is connected to the upper connector, and the other end is connected to the main tube; a valve ball and a valve ball return spring are sequentially arranged inside the one-way valve body. This prior art ensures continuous injection of well washing fluid.

[0015] The existing technology is not as effective as the present invention in actual use.

[0016] In summary, the technical solutions, technical problems to be solved, and beneficial effects of the above-disclosed technologies are all different from those of this utility model. For more technical features, technical problems to be solved, and beneficial effects of this utility model, the above-disclosed technical documents do not provide any technical inspiration. Utility Model Content

[0017] In view of the above-mentioned defects in the existing technology, the purpose of this utility model is to provide a circulating sand flushing fluid reversing device, which can continuously circulate the workover fluid at the wellhead without stopping the pump during sand flushing and switching of a single shaft or other workover operations, thereby improving the construction efficiency of sand flushing and other workover operations, reducing operating costs, and reducing well site pollution and downhole construction accidents.

[0018] To achieve the above objectives, the present invention adopts the following technical solution:

[0019] A circulating sand flushing liquid reversing device includes a straight connecting pipe, a coupling, and an outer cylinder connected sequentially from top to bottom. The device is characterized in that a liquid control valve is connected to the upper end of the straight connecting pipe, and a liquid outlet hole is provided on the wall of the outer cylinder; a liquid outlet hole sealing device is provided inside the outer cylinder.

[0020] The liquid control valve includes a valve body and a valve ball;

[0021] The valve body is axially continuous, and a spherical space matching the valve ball is provided in the valve body, wherein the axial diameter of the spherical space is smaller than the diameter of the sphere.

[0022] An operating hole is radially provided in the spherical space to connect the spherical space with the outside world;

[0023] The valve ball is provided with a through hole penetrating the center of the ball, and also with an operating handle perpendicular to the axis of the through hole;

[0024] The valve ball is disposed in the spherical space of the valve body, and the operating handle is placed in the operating hole of the valve body.

[0025] The liquid outlet sealing device is a sealing cylinder. The upper end of the sealing cylinder is connected to the inner wall of the lower end of the straight connecting pipe. When the straight connecting pipe is locked with the coupling, the lower end face of the sealing cylinder is below the liquid outlet of the outer cylinder; the liquid outlet is sealed by the sealing cylinder.

[0026] The straight connecting pipe is equipped with an anti-back-turning device above the connection point with the coupling;

[0027] The anti-tipping device includes a lever, a fixing spring, and a fixing locking pin;

[0028] The pin body of the fixing pin has a Z-shaped structure. The middle part of the fixing pin is fixed to the pipe wall of the straight connecting pipe by a pin shaft. One end of the fixing pin is provided with a locking hook, which can be engaged in the slot provided at the upper end of the coupling.

[0029] One end of the fixed spring contacts the spring seat, and the other end presses the locking hook of the fixed locking pin into the slot;

[0030] The lever is located on the wall of the straight connecting pipe above the other end of the fixing pin. The lever has a protrusion. By rotating the lever, one end of the fixing pin is pressed down, causing the locking hook to lift.

[0031] The spring seat is fixed to the outer wall of the straight connecting pipe, and the maximum outer diameter formed by the anti-backlash device is smaller than the outer diameter of the coupling.

[0032] The outer wall of the direct connection pipe is provided with a countersunk hole for a wrench.

[0033] The sealing cylinder is provided with a shoulder that divides the sealing cylinder into a small-diameter cylinder and a large-diameter cylinder;

[0034] The small-diameter cylinder is connected to the straight pipe, and the large-diameter cylinder blocks the liquid outlet hole;

[0035] The outer diameter of the small-diameter cylinder is the same as the inner diameter of the straight connecting pipe and the inner diameter of the coupling, and the inner diameter of the large-diameter cylinder is the same as the inner diameter of the sealing cylinder.

[0036] When the outlet hole is blocked, the shoulder does not contact the coupling;

[0037] When the shoulder contacts the coupling, the liquid outlet is in the open state.

[0038] The lower end of the large-diameter cylinder is provided with a first sealing ring and a second sealing ring.

[0039] When the liquid outlet is blocked, the first sealing ring is above the liquid outlet and the second sealing ring is below the liquid outlet.

[0040] The upper end of the sealing cylinder is either integrally machined with the straight connecting pipe or connected by threads.

[0041] The lower outer circle of the sealing cylinder is clearance-fitted with the inner circle of the outer cylinder; the first sealing ring and the second sealing ring complete the sealing of both sides of the liquid outlet hole.

[0042] The outer cylinder has two or more liquid outlet holes;

[0043] The outer cylinder is provided with a thickened wall, which is located in the area where the liquid outlet is located.

[0044] Its characteristic is that the lower end of the outer cylinder is connected to the sand-flushing oil pipe.

[0045] The lower end of the outer cylinder is provided with an external thread, which is an oil pipe thread. The outer cylinder is connected to the sand flushing oil pipe through an oil pipe coupling.

[0046] Compared with the prior art, the present invention has the following advantages:

[0047] 1. It can effectively prevent sand from blocking the oil pipe or sand from jamming the flushing pipe string when pouring single pipes;

[0048] 2. It enables continuous pump circulation, improving work efficiency;

[0049] 3. Excellent sealing effect, no leakage, and will not cause wellhead pollution;

[0050] 4. It can be reused, reducing operating costs. Attached Figure Description

[0051] Figure 1 This is a schematic diagram of the structure of a circulating sand flushing liquid reversing device according to the present invention;

[0052] Figure 2 This is a utility model Figure 1 Schematic diagram of the structure of the liquid control valve;

[0053] Figure 3 This is a utility model Figure 1 A schematic diagram of the external structure of the anti-overturning device;

[0054] In the diagram: 1. Internal thread; 2. Valve body; 3. Valve ball; 4. Operating handle; 5. Upper external thread; 6. Straight connecting pipe; 7. Upper internal thread of coupling; 8. Lower external thread of straight connecting pipe; 9. Coupling; 10. Outer cylinder; 11. First sealing ring; 12. First sealing ring groove; 13. Sealing cylinder; 14. Liquid outlet; 15. Second sealing ring groove; 16. Second sealing ring; 17. Lower external thread of cylinder; 18. Countersunk hole of wrench; 19. Pulley; 20. Fixing spring; 21. Fixing locking pin; 22. Slot; 23. Thickened wall; Detailed Implementation

[0055] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0056] Example 1:

[0057] Please see Figures 1 to 3 The present invention provides a circulating sand flushing liquid reversing device, comprising a liquid control valve, a straight connecting pipe 6, a coupling 9, and an outer cylinder 10 connected in sequence from top to bottom. The upper end of the straight connecting pipe 6 is connected to the liquid control valve; the outer cylinder 10 is provided with a liquid outlet hole 14; and a liquid outlet hole sealing device is provided inside the outer cylinder 10.

[0058] The liquid control valve includes a valve body 2 and a valve ball 3. The valve body 2 is axially continuous and has a spherical space that matches the valve ball 3. The axial diameter of the spherical space is smaller than the diameter of the ball. An operating hole is radially provided in the spherical space, connecting the spherical space to the outside. The valve ball 3 has a through hole penetrating its center and an operating handle 4 perpendicular to the axis of the through hole. The valve ball 3 is located in the spherical space of the valve body 3, and the operating handle 4 is placed in the operating hole of the valve body 3. The valve ball 3 is adjusted by the operating handle 4 to realize the on / off state of the liquid control valve.

[0059] The liquid outlet sealing device is a sealing cylinder 13. The upper end of the sealing cylinder 13 is connected to the inner wall of the lower end of the straight connecting pipe 6, and the lower end face of the sealing cylinder 13 is below the liquid outlet 14 of the outer cylinder 10. The liquid outlet 14 is closed by the sealing cylinder 13, and is blocked and opened by the sealing cylinder 13.

[0060] In this embodiment, the device is connected to the coupling of the downhole tubing during use. The device is moved to the tee between the wellhead self-sealing device and the self-sealing device. A water hose is then connected to the circulation pool at the tee. The liquid outlet 14 in this device is located in the tee installed between the two self-sealing devices.

[0061] During sand flushing or other well workover operations, the sealing cylinder 13 blocks the liquid outlet 14 at the lower end of the outer cylinder 10, and the liquid flow channel in the valve ball 3 of the liquid control valve is in the open position, allowing the workover fluid to circulate normally between the downhole tubing and casing.

[0062] When a single section of tubing needs to be drained or when circulating workover fluid is required during other construction operations, the hoisting clamp holding this device is positioned on the upper end of the self-sealing device. The straight connecting pipe 6 is rotated upwards, causing the sealing cylinder 13 to rise and expose the outlet hole 14. Then, the fluid flow channel in the valve ball 3 is closed using the operating handle 4. The pump at the wellhead remains running, and the workover fluid flows through the outlet hole 14, the tee pipe, and the water hose connected to the radial port of the tee pipe to the circulation pool. The workover fluid can continuously circulate between the well and the wellhead.

[0063] It should be noted that the wellhead self-sealing device, the self-sealing device and the tee pipe are existing technologies, which are known to those skilled in the art.

[0064] This embodiment has a simple structure and works in conjunction with the wellhead device to switch the circulating workover fluid at the wellhead to the circulation pool, completely solving the problem that current sand flushing operations and other workover operations require stopping the pump and not circulating the workover fluid.

[0065] Example 2:

[0066] Please refer to this carefully. Figure 3 An anti-reverse buckling device is provided below the countersunk hole 18 of the wrench in the straight connecting pipe 6. The anti-reverse buckling device includes a lever plate 19, a fixing spring 20, and a fixing locking pin 21. The pin body of the fixing locking pin 21 has a Z-shaped structure. The middle part of the locking body of the fixing locking pin 21 is fixed to the pipe wall of the straight connecting pipe 6 by a pin shaft. The lower end of one end of the fixing locking pin 21 is provided with a locking hook, which can be engaged in the slot 22 on the upper outer wall of the coupling 9. One end of the fixing spring 20 contacts the spring seat, and the other end presses the locking hook of the fixing locking pin 21 into the slot 22. The lever plate 19 is installed on the pipe wall of the straight connecting pipe 6 above the other end of the fixing locking pin 21 by a pin shaft. The lever plate 19 is provided with a protrusion. When the protrusion contacts the fixing locking pin 21, one end of the fixing locking pin 21 moves down, and the locking hook of the other end disengages from the slot 22.

[0067] The spring seat is fixed on the outer wall of the straight connecting pipe 6, and the maximum outer diameter formed by the anti-backlash device is smaller than the outer diameter of the coupling 9.

[0068] After the trapezoidal thread of the straight connecting pipe 6 is tightened, the fixing locking pin 21 is locked in the slot 22 at the upper end of the coupling 9, which can prevent the trapezoidal thread of the straight connecting pipe 6 from rotating and turning back. When it is necessary to loosen the straight connecting pipe 6, rotate the lever 19 to make the locking hook disengage from the slot 22.

[0069] The two ends of the straight connecting pipe 6 are respectively provided with an upper external thread 5 and a lower external thread 8. The upper external thread 5 is a coarse thread, and the lower external thread 8 is a trapezoidal thread. The upper and lower ends of the straight connecting pipe 6 can be threadedly connected to the valve body 2 and the coupling 9, respectively.

[0070] The valve body 2 has an upper internal thread 1 and a lower internal thread at its two ends, respectively. The upper internal thread 1 is an oil pipe thread and can be connected to an oil pipe or a sand flushing faucet thread. The lower internal thread is a coarse thread and can be connected to the upper external thread 5 of a straight connecting pipe.

[0071] The outer wall of the straight connecting pipe 6 is provided with a countersunk hole 18 for wrenches, which can be easily rotated by using pipe wrenches or countersunk holes to make the straight connecting pipe 6 drive the sealing cylinder 13 to move upward to open the fluid outlet 14 or move downward to block the fluid outlet 14, so that the workover fluid is kept in continuous circulation between the downhole and the wellhead or in normal circulation between the tubing and the casing during normal workover operations.

[0072] The upper end of the coupling 9 is provided with an internal thread 7, which is a trapezoidal thread and can be threadedly connected to the lower end external thread 8 of the straight connecting pipe; the lower end of the coupling 9 is provided with a fine-pitch internal thread and can be connected to the fine-pitch external thread on the upper end of the outer cylinder 10. The length of the coupling 9 is set to be more than 18cm. The trapezoidal internal thread 7 at the upper end of the coupling 9 makes the rotation between the straight connecting pipe 6 and the coupling 9 smoother and faster.

[0073] The sealing cylinder 13 is provided with a shoulder that divides the sealing cylinder 13 into a small-diameter cylinder and a large-diameter cylinder. The small-diameter cylinder is connected to the straight connecting pipe 6, and the large-diameter cylinder blocks the liquid outlet hole 14. The outer diameter of the small-diameter cylinder is the same as the inner diameter of the straight connecting pipe 6 and the inner diameter of the coupling 9. The inner diameter of the large-diameter cylinder is the same as the inner diameter of the sealing cylinder. When the liquid outlet hole 14 is in the blocked state, the shoulder does not contact the coupling 9. When the shoulder contacts the coupling 9, the liquid outlet hole 14 is in the open state.

[0074] The lower end of the large-diameter cylinder is provided with a first sealing ring 11 and a second sealing ring 16; when the liquid outlet 14 is in a blocked state, the first sealing ring 11 is above the liquid outlet 14 and the second sealing ring 16 is below the liquid outlet 14.

[0075] The upper end of the sealing cylinder 13 is integrally machined or threadedly connected to the straight connecting pipe 6, and the lower outer circle of the sealing cylinder 13 is clearance-fitted with the inner circle of the outer cylinder 10; when the straight connecting pipe 6 and the sealing cylinder 13 move smoothly, the first sealing ring 11 and the second sealing ring 16 complete the sealing of both sides of the liquid outlet hole 14.

[0076] The total length of the straight connecting pipe 6 and the sealing cylinder 13 is greater than the distance between the upper and lower self-sealing devices at the wellhead, ensuring that the liquid outlet hole 14 in the outer cylinder 10 located in the three-way pipe between the two self-sealing devices can be closed normally.

[0077] The lower end of the outer cylinder 10 is an external thread 17, which is a pipe thread that can be connected to the pipe coupling thread. The outer cylinder 10 has two or more outlet holes 14. The outer cylinder 10 is provided with a thickened wall 23, which is the cylinder wall where the outlet holes 14 are located, in order to improve the tensile strength of the outer cylinder 10.

[0078] This device is installed on the upper end of the sand flushing tubing. It can be run down into the well with each sand flushing tubing and connected to the sand flushing string.

[0079] In well workover operations requiring continuous circulation of sand-flushing fluid, the method of using this invention is illustrated below, taking sand-flushing operations as an example:

[0080] 1. This utility model is lowered into the well along with the sand flushing tubing. First, install one of this utility model on each sand flushing tubing to be lowered into the well and open the liquid control valve by operating handle 4. Rotate the straight connecting pipe 6 downwards. The straight connecting pipe 6 drives the sealing cylinder 13 downwards to seal the liquid outlet 14. Alternatively, the above operation can be performed before the sand flushing tubing is lowered into the well to seal the liquid outlet 14 of each device. The fixing locking pin 21 is exactly locked in the groove 22 of the coupling 9.

[0081] 2. Install two self-sealing devices above the wellhead sealer or blowout preventer, connect a tee pipe between the two self-sealing devices, connect a water hose to the outside of the radial opening of the tee pipe, and connect the water hose to the circulation tank.

[0082] 3. Connect the upper internal thread 1 of the valve body 2 of this utility model at the upper end of the sand flushing tubing to the faucet, and connect it to the water inlet of the pump truck through the faucet and water hose. Lift up the sand flushing tubing of this utility model. Connect the lower external thread 17 of the outer cylinder 10 to the tubing coupling at the upper end of the sand flushing tubing string or well workover tubing string in the well. Connect the water outlet of the pump truck to the annulus of the casing and tubing. The well flushing fluid reaches the bottom of the well from the annulus of the casing and tubing, returns from the tubing, and enters the pump truck through this utility model to form a sand flushing circulation channel.

[0083] 4. After flushing one sand-flushing oil pipe, use a lifting clamp to suspend the lower end face of coupling 9 in this device onto the upper end face of the upper self-sealing device.

[0084] 5. When continuous circulation of flushing fluid is required during single-line flushing or other well workover operations, move the lever 19 to compress the locking pin 21 and move it upward, disengaging it from the groove 22 of the coupling 9. Then rotate the straight connecting pipe 6 upward, which will drive the sealing cylinder 13 upward to expose the outlet hole 14. Then close the fluid flow channel in the valve ball 3 through the operating handle 4. The flushing fluid will flow from the outlet hole 14, the three-way pipe and the water hose into the circulation pool.

[0085] 6. Remove the faucet, and connect the lower end of the next sand-flushing oil pipe (which is connected to this utility model) to the upper end of the valve body of this utility model installed on the sand-flushing oil pipe of the sand-flushing string in the well. Connect the upper end of the valve body of this utility model installed on the upper end of the sand-flushing oil pipe to the faucet, and connect the faucet and water hose to the water inlet of the pump truck to form a sand-flushing circulation channel. Then continue to flush the sand to the designed depth by switching the faucet, this utility model and the sand-flushing oil pipe in the above manner.

[0086] It enables normal circulation of flushing fluid in and at the wellhead without stopping the pump, avoiding pump shutdown operations, improving flushing efficiency and other operational efficiency, and preventing situations such as sand blockage of oil tubing and sand jamming of flushing tubing caused by long replacement time for a single tube.

[0087] All components not discussed in detail in this application, as well as the connection methods of these components, are well-known technologies in this field. They can be directly applied and will not be elaborated further.

[0088] In this utility model, the term "multiple" refers to two or more unless otherwise explicitly defined. The terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; "linking" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0089] In the description of this utility model, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or unit referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0090] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0091] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A circulating sand flushing liquid reversing device, comprising a straight connecting pipe, a coupling, and an outer cylinder connected sequentially from top to bottom, characterized in that, A liquid control valve is connected to the upper end of the straight connecting pipe; The outer cylinder wall is provided with a liquid outlet hole; the outer cylinder is provided with a liquid outlet hole sealing device; The liquid outlet sealing device is a sealing cylinder. The upper end of the sealing cylinder is connected to the inner wall of the lower end of the straight connecting pipe. When the straight connecting pipe is locked with the coupling, the lower end face of the sealing cylinder is below the liquid outlet of the outer cylinder; the liquid outlet is sealed by the sealing cylinder. An anti-reverse buckling device is provided above the connection point between the straight pipe and the coupling; The anti-tipping device includes a lever, a fixing spring, and a fixing locking pin; The pin body of the fixing pin has a Z-shaped structure. The middle part of the fixing pin is fixed to the pipe wall of the straight connecting pipe by a pin shaft. One end of the fixing pin is provided with a locking hook, which can be engaged in the slot provided at the upper end of the coupling. The upper end of the fixed spring contacts the spring seat, and the lower end presses the locking hook of the fixed locking pin into the slot; The lever is set on the pipe wall of the straight connecting pipe above the other end of the fixed locking pin. The lever has a protrusion. By rotating the lever, one end of the fixed locking pin is pressed down, causing the locking hook of the fixed locking pin to be lifted. The sealing cylinder is provided with a shoulder that divides the sealing cylinder into a small-diameter cylinder and a large-diameter cylinder; The small-diameter cylinder is connected to the straight pipe, and the large-diameter cylinder blocks the liquid outlet hole; The outer diameter of the small-diameter cylinder is the same as the inner diameter of the straight connecting pipe and the inner diameter of the coupling, and the inner diameter of the large-diameter cylinder is the same as the inner diameter of the sealing cylinder. When the outlet hole is blocked, the shoulder does not contact the coupling; When the shoulder contacts the coupling, the liquid outlet is in the open state; The lower end of the large-diameter cylinder is provided with a first sealing ring and a second sealing ring. When the outlet is blocked, the first sealing ring is above the outlet and the second sealing ring is below the outlet; the first and second sealing rings complete the sealing of both sides of the outlet.

2. The circulating sand flushing liquid reversing device according to claim 1, characterized in that, The liquid control valve includes a valve body and a valve ball; The valve body is axially continuous, and a spherical space matching the valve ball is provided in the valve body, wherein the axial diameter of the spherical space is smaller than the diameter of the sphere. An operating hole is radially provided in the spherical space to connect the spherical space with the outside world; The valve ball is provided with a through hole penetrating the center of the ball, and also with an operating handle perpendicular to the axis of the through hole; The valve ball is disposed in the spherical space of the valve body, and the operating handle is placed in the operating hole of the valve body.

3. The circulating sand flushing liquid reversing device according to claim 1, characterized in that, The spring seat is fixed to the outer wall of the straight connecting pipe, and the maximum outer diameter formed by the anti-backlash device is smaller than the outer diameter of the coupling.

4. The circulating sand flushing liquid reversing device according to claim 1, characterized in that, The outer wall of the direct connection pipe is provided with a countersunk hole for a wrench.

5. The circulating sand flushing liquid reversing device according to claim 1, characterized in that, The upper end of the sealing cylinder is either integrally machined with the straight connecting pipe or connected by threads. The lower outer circle of the sealing cylinder is clearance-fitted with the inner circle of the outer cylinder.

6. The circulating sand flushing liquid reversing device according to claim 1, characterized in that, The outer cylinder is provided with at least two liquid outlet holes; The outer cylinder is provided with a thickened wall, which is located in the area where the liquid outlet is located.

7. A circulating sand flushing liquid reversing device according to any one of claims 1-6, characterized in that, The lower end of the outer cylinder is connected to the sand flushing oil pipe.

8. A circulating sand flushing liquid reversing device according to claim 7, characterized in that, The lower end of the outer cylinder is provided with an external thread, which is an oil pipe thread. The outer cylinder is connected to the sand flushing oil pipe through an oil pipe coupling.

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