Sealed sand prevention throttler

Abstract

The utility model relates to the field of well holes in wells or valve devices of the wells, in particular to a sealing sand prevention flow controller which comprises a central pipe and a first connector, a liquid passing hole is formed in the central pipe, and a piston is further sleeved on the central pipe in a sealing and sliding mode. The center pipe is further provided with a spring which enables the piston and the first connector to keep tight contact so as to seal the liquid passing hole, and the piston and / or the first connector are / is provided with a flexible sealing ring so that the contact position of the piston and the first connector can be sealed. The sand prevention throttling device solves the problem that in the prior art, in the well washing process of a sand prevention throttling device, gravel or impurities may be left between a throttling sleeve and a corresponding connector, so that sealing fails when the throttling device is closed.

Description

Technical Field

[0001] The utility model relates to the field of a wellbore or a well valve device, in particular to a sealing sand-proof throttle. Background Art

[0002] The throttle is a commonly used downhole control tool in oil fields. It is mainly used in processes such as stratified water injection, leakage detection, chemical water plugging and acidification. In the existing technology, the throttle is generally used in conjunction with a hydraulic expansion packer. The high-pressure liquid acts on the inner cavity of the rubber tube through the pressure transmission pores inside the packer. Under the throttling pressure difference of the throttle, the rubber tube expands to isolate the annulus of the oil casing. When the oil pressure is released and the pressure of the oil casing is balanced, the rubber tube shrinks back to its original state by its own resilience to achieve unsealing.

[0003] However, after the pump is stopped, the throttle in the prior art is still in an open state, and the pressure inside and outside the oil pipe will be balanced. At this time, the hydraulic expansion packer will fail, resulting in the inability to carry out subsequent processes.

[0004] The Chinese utility model patent with the authorization announcement number CN219587546U discloses a throttle that can prevent back-spitting, including an upper joint and a lower joint, a center tube is arranged between the upper joint and the lower joint, an adjustment sleeve is detachably connected to one end of the upper joint near the lower joint, and a throttle sleeve is detachably connected to one end of the lower joint near the upper joint, and the throttle sleeve is sleeved on the outer periphery of the center tube, and a spring is arranged between the adjustment sleeve and the throttle sleeve, which is located on the outer periphery of the center tube. When a certain pressure is reached, the throttle sleeve is pushed upward to compress the spring, open the water injection channel to realize water injection, and when the injection is stopped, the throttle sleeve is reset and closed under the action of the spring force, which can prevent the formation from spitting out sand through the throttle. And after the water injection and other operations are completed, the technical solution disclosed in the patent is that the throttle sleeve is reset and closed under the action of the spring force, so that the pressure difference between the inside and outside of the oil pipe still exists, and the packer will not fail.

[0005] However, if the throttle disclosed in the technical solution of the patent is used, and the well washing operation is performed before the throttle is closed, gravel or impurities may be left between the piston and the lower joint during the well washing operation. When the piston is reset, the gravel or impurities are clamped by the piston and the lower joint, and the throttle cannot be completely closed, which results in the throttle being unable to achieve the effects of pressure maintenance and sand prevention. Utility Model Content

[0006] The utility model aims to provide a sealed sand-proof throttle to solve the problem that sand or impurities may remain between the throttle sleeve and the corresponding joint during the well washing process in the prior art, resulting in sealing failure when the throttle is closed.

[0007] A sealing and sand control throttle device, comprising a central tube and a first joint. The central tube is provided with liquid passing holes, and a piston is hermetically and slidably sleeved on the central tube. A spring is also arranged on the central tube to keep the piston in close contact with the first joint to close the liquid passing holes. A flexible sealing ring is arranged on the piston and / or the first joint to seal the contact position between the two.

[0008] Further, the flexible sealing ring includes an annular main body and an outer flange. The piston is provided with an installation groove for installing the flexible sealing ring. The installation groove includes a concave part, and the concave part cooperates with the outer flange to limit the flexible sealing ring in the axial direction.

[0009] Further, the piston is provided with an annular groove extending axially. A retaining ring is installed in the annular groove, and the retaining ring cooperates with the groove wall of the installation groove on the piston to limit the flexible sealing ring in the radial direction.

[0010] Further, one side of the retaining ring contacts the central tube, and the other side contacts the piston. The retaining ring and the piston are in a blocking fit in the direction away from the first joint. When the piston contacts the first joint, there is a certain distance between the retaining ring and the first joint. The side of the retaining ring facing the first joint forms a pressure-bearing surface for receiving water pressure.

[0011] Further, the end face of the piston in contact with the first joint is a conical surface, the end face of the flexible sealing ring is an inclined surface adapted to the end face of the piston, and the end face of the first joint in contact with the piston is an inclined surface adapted to the conical surface of the piston.

[0012] Further, the sealing and sand control throttle device further includes a second joint. The first joint is a lower joint, and the second joint is an upper joint.

[0013] Further, an adjusting ring is movably installed on the second joint. The spring is sleeved on the central tube. By adjusting the position of the adjusting ring relative to the first joint, the initial compression amount of the spring can be changed.

[0014] Further, the adjusting ring is movably installed on the second joint through threads.

[0015] The utility model improves the prior art. Specifically: when in use, when the pressure in the central tube of the throttle device is too high, the piston is pushed to open the liquid passing holes. When the pressure in the central tube of the throttle device is less than a certain pressure, under the action of the spring, the liquid passing holes are closed again by the cooperation of the reset piston and the first joint. Due to the flexible sealing structure arranged on the piston and / or the first joint, when flushing the well normally through the throttle device, even if there are sand grains or impurities clamped between the two, the flexible sealing structure can seal between the two by relying on its own deformation, solving the problem that in the prior art, sand grains or impurities may remain between the piston and the corresponding joint during the well flushing process, resulting in sealing failure when the throttle device is closed. Description of the Drawings

[0016] Figure 1 It is: a structural schematic diagram of the sealing and sand control throttle of the first embodiment of the sealing and sand control throttle of the present utility model.

[0017] In the figure: 1. Second joint; 2. Sealing ring; 3. Spring; 4. Piston; 5. Flexible sealing ring; 6. Retaining ring; 7. Liquid passing hole; 8. Central tube; 9. First joint; 10. Spacer ring; 11. Ring groove; 12. Installation groove; 13. Adjusting ring. Specific implementation mode

[0018] Specific concept of the sealing and sand control throttle of the present utility model:

[0019] A sealing and sand control throttle includes a first joint and a central tube sealingly connected to the first joint. A liquid passing hole is provided on the central tube, and a piston is also sealingly sleeved and slidably arranged on the central tube. A spring is also arranged on the central tube to keep the piston in close contact with the first joint to close the liquid passing hole. A flexible sealing ring is arranged on the piston and / or the first joint to seal the contact position between the two.

[0020] When the pressure in the tubing is too high, the liquid in the tubing drives the piston to move and compress the spring to open the liquid passing hole, so that the liquid inside the tubing can flow into the tubing annulus. When the pressurization in the tubing stops, the pressure in the tubing drops. Under the action of the spring, the piston resets to close the liquid passing hole again. Due to the existence of the acting force of the spring, when the piston and the first joint cooperate to close the liquid passing hole, the pressure in the tubing is greater than the pressure in the tubing-casing annulus, thereby ensuring that the packer will not easily fail.

[0021] The present utility model closes the liquid passing hole through the cooperation of the piston and the first joint. In order to ensure the reliability of the seal, a ring-shaped flexible sealing structure is arranged on the piston and / or the first joint. When the piston is opened and closed again, even if there are sand grains or impurities during well flushing staying between the piston and the corresponding joint, the ring-shaped flexible seal can rely on its own deformation to seal the surface where the piston contacts the first joint again, solving the problem that in the prior art, sand grains or impurities may stay between the piston and the first joint during well flushing, resulting in seal failure when the throttle is closed.

[0022] The features and performance of the present utility model are further described in detail below in conjunction with embodiments.

[0023] The first embodiment of the sealing and sand control throttle of the present utility model:

[0024] As Figure 1As shown: A sealing and sand control restrictor includes a first joint 9, a second joint 1, and a central tube 8 sealingly connected between the first and second joints 1. The first joint 9 and the second joint 1 are sealingly connected to the central tube 8 through a sealing ring 2. The central tube 8 is provided with liquid passing holes 7. A piston 4 is also sealingly and slidably sleeved on the central tube 8. A spring 3 is also arranged on the central tube 8 to keep the piston 4 in close contact with the first joint 9 to close the liquid passing holes 7. The spring 3 is sleeved on the central tube 8, and corresponding spacer rings 10 are arranged at both ends of the spring 3. One side of the spacer ring 10 abuts against the second joint 1, and the other side of the spacer ring 10 abuts against the piston 4. A flexible sealing ring 5 is arranged on the piston 4 to seal the contact position between the piston 4 and the first joint 9. The end of the piston 4 in contact with the first joint 9 is tapered, and the end of the first joint 9 in contact with the piston 4 is also provided with an inclined surface structure adapted to the tapered piston 4. When the piston 4 contacts the first joint 9, the end of the flexible sealing ring 5 is flush with the end of the piston 4. Of course, in other embodiments, it may also be that the flexible sealing ring 5 is arranged on the piston 4 and the first joint 9 or the flexible sealing ring 5 is arranged on the first joint 9.

[0025] The flexible sealing ring 5 can adopt a common sealing rubber ring in the prior art. A corresponding annular installation groove is opened at the end of the piston 4, and the sealing rubber ring is installed in the annular installation groove. Since the liquid in the central tube 8 was originally in a high-pressure environment and would have a very high speed when discharged through the liquid passing holes 7, if a common sealing rubber ring in the prior art is used as the flexible sealing ring 5, the flexible sealing ring 5 may be disengaged from the piston 4, resulting in sealing failure. Therefore, preferably: The flexible sealing ring 2 includes an annular main body and an outer flange. An installation groove 12 for installing the flexible sealing ring 2 is opened on the piston 4. The installation groove 12 includes a concave portion. The concave portion and the outer flange cooperate to limit the flexible sealing ring 2 in the axial direction to prevent the flexible sealing ring 2 from moving. An annular installation groove 12 is opened on the side of the piston 4 close to the central tube 8, and a concave portion is opened on the side of the installation groove 12 close to the second joint 1. During assembly, the flexible sealing ring 5 is installed in the installation groove 12, and the outer flange of the flexible sealing ring 5 is installed in the concave portion of the installation groove 12, so that the side wall of the concave portion and the outer flange of the flexible sealing ring 5 are in a blocking fit in the axial direction, thereby ensuring that the flexible sealing ring 5 will not easily disengage from the piston 4 when following the movement of the piston 4.

[0026] However, to ensure that the flexible sealing ring 5 does not detach from the piston 4, the width of the notch of the installation groove 12 is equal to or even smaller than the thickness of the annular body of the flexible sealing ring 5. This results in extremely difficult installation when installing the flexible sealing ring 5. Therefore, to reduce the installation difficulty of the flexible sealing ring 5 and further improve the assembly efficiency, preferably: a ring groove 11 extending axially is provided on the piston 4, and a retaining ring 6 is installed in the ring groove 11. The retaining ring 6 cooperates with the groove wall of the installation groove 12 on the piston 4 to limit the flexible sealing ring 2 in the radial direction. When installing the flexible sealing ring 5, due to the presence of the ring groove 11, the flexible sealing ring 5 can first enter the installation groove 12 through the cooperation of the ring groove 11 and the installation groove 12, and the outer flange of the flexible sealing ring 5 can be easily sent into the concave portion. However, due to the presence of the ring groove 11, the flexible sealing ring 5 has a certain amount of movement in the radial direction. Therefore, a retaining ring 6 is installed in the ring groove 11, and the flexible seal is fixed in the radial direction through the cooperation of the retaining ring 6 and the groove wall of the installation groove 12. By providing the retaining ring 6 and the ring groove 11, the installation difficulty of the flexible sealing ring 5 is reduced, making the assembly more convenient.

[0027] If the liquid in the throttler is to push the piston 4 towards the second joint 1 under the action of pressure and allow the liquid passing hole 7 to pass through, a corresponding pressure-bearing surface needs to be provided on the piston 4. A bevel can be provided on one side of the piston 4 close to the liquid passing hole 7 of the central tube 8, and the liquid in the central tube 8 exerts a force on the bevel to push the piston 4 towards the first joint 9. However, in this way, the processing process is slightly cumbersome, and it is necessary to machine the installation groove 12, the ring groove 11, and the bevel on the piston 4. Therefore, preferably: one side of the retaining ring 6 contacts the central tube 8, and the other side contacts the piston 4. The retaining ring 6 and the piston 4 are in a blocking fit in the direction away from the first joint 9. When the piston 4 contacts the first joint 9, the retaining ring 6 has a certain distance from the first joint 9. The side of the retaining ring 6 facing the first joint 9 forms a pressure-bearing surface for receiving the water pressure. The ring groove 11 is provided on the side of the piston 4 close to the central tube 8, so that the retaining ring 6 is arranged adjacent to the central tube 8. And there is a certain distance between the retaining ring 6 and the first joint 9, so that the liquid in the central tube 8 can enter between the end of the retaining ring 6 and the first joint 9, and directly exert a force on the end of the retaining ring 6 in the direction of the second joint 1. And the retaining ring 6 and the bottom of the ring groove 11 of the piston 4 are in a blocking fit in the direction away from the first joint 9 and close to the second joint 1, so that the retaining ring 6 can push the piston 4 in the direction away from the first joint 9, achieving the purpose of allowing the liquid passing hole 7 to pass through. Using the end of the retaining ring 6 as the pressure-bearing surface relatively saves the step of machining the pressure-bearing surface, reduces the manufacturing difficulty of the entire device, and saves machining time.

[0028] The ends of the piston 4, the flexible sealing ring 5, and the first joint 9 can all adopt planes. For further optimization, the end face of the piston 4 in contact with the first joint 9 is a conical surface, and the end face of the flexible sealing ring 5 is a conical surface. The cone angles of the two are the same. The end face of the first joint 9 in contact with the piston 4 is an inclined surface adapted to the conical surface of the piston. The ends of the piston and the flexible sealing ring fixed on the piston are arranged in a conical shape. The cooperation between the conical surface and the matching inclined surface further improves the tightness of the contact between the piston 4 and the first joint 9, ensuring the reliability of the seal between the two.

[0029] There is no restriction on which joint the first joint 9 and the second joint 1 are. For example: the first joint 9 is the upper joint and the second joint 1 is the lower joint; or the first joint 9 is the lower joint and the second joint 1 is the upper joint. However, if the first joint 9 is the upper joint, when the spring 3 makes the piston 4 in close contact with the first joint 9, it needs to overcome the gravity of the piston 4 itself. Relatively speaking, the piston 4 can move more easily to open the liquid passing hole 7. Therefore, preferably: the first joint 9 is the lower joint and the second joint 1 is the upper joint. In this way, when the piston 4 moves, it not only needs to overcome the force exerted by the spring 3, but also needs to overcome the gravity of the piston 4 itself, making it easier for the piston 4 to reset and further ensuring a larger pressure difference inside and outside the throttle.

[0030] At the same time, in order to adjust the opening pressure of the liquid passing hole 7 of the throttle, the initial elastic force of the spring 3 needs to be adjusted. Preferably: an adjusting ring 13 is movably installed on the second joint 1. By adjusting the position of the adjusting ring 13 relative to the first joint 9, the initial compression amount of the spring is changed. The adjusting ring 13 is in a blocking fit with the cushion ring 10 abutted against the second joint 1. An elastic piece extending away from the first joint 9 is arranged inside the adjusting ring 13, and a plurality of axially extending grooves are formed on the second joint 2. The elastic piece can be clamped in the grooves. By adjusting the elastic piece to be clamped in different grooves, the position of the cushion ring 10 is adjusted to achieve the purpose of changing the initial compression amount of the spring.

[0031] However, relatively speaking, the adjustment accuracy of this method is not high. The elastic piece can only be transferred from one groove to another groove, and the adjusting ring 13 cannot be fixed at the position between the two grooves. Therefore, preferably: the adjusting ring 13 is movably installed on the second joint 1 through a thread. The adjusting ring 13 is provided with an internal thread, and the second joint 1 is provided with an external thread matching the internal thread of the adjusting ring 13. The adjusting ring 13 is adjustably installed on the second joint 1 through a thread. When the initial elastic force of the spring 3 needs to be adjusted, the adjusting ring 13 is screwed, thereby changing the position of the cushion ring 10 and further changing the initial elastic force of the spring 3.

[0032] During use, liquid is injected into the tubing and pressured until the pressure in the tubing is maintained at 15 MPa. When the pressure in the well reaches 15 MPa, the liquid in the well pushes the baffle and then drives the piston 4 to move, causing the piston 4 to move away from the first joint 9 and open the liquid passing hole 7. The liquid in the well flows out. When the injection and pressure application stop, under the action of the spring 3, the piston 4 is pushed to move towards the first joint 9 until the piston 4 contacts the first joint 9 and squeezes the flexible sealing ring 5 to seal between the two, and the piston 4 and the first joint 9 close the liquid passing hole 7 again. After the pump stops, the pressure in the well does not drop within 30 minutes, indicating that the packer has good sealing performance.

[0033] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. The patent protection scope of the present invention is subject to the claims. Any equivalent structural changes made by using the description and drawings of the present invention should, by the same token, be included in the protection scope of the present invention.

Claims

1. A sealed sand control throttle, comprising a central tube and a first joint, wherein a liquid passage hole is provided on the central tube, a piston is provided on the central tube in a sealing sliding sleeve, and a spring is provided on the central tube to keep the piston in close contact with the first joint to close the liquid passage hole, wherein the characteristics are: A flexible sealing ring is arranged on the piston and / or the first joint to seal the contact position between the two.

2. The sealing sand control throttle according to claim 1, characterized in that: The flexible sealing ring comprises an annular body and an outer flange. The piston is provided with an installation groove for installing the flexible sealing ring. The installation groove comprises an inner recess. The inner recess cooperates with the outer flange to limit the flexible sealing ring in the axial direction.

3. The sealing sand control throttle according to claim 2, characterized in that: The piston is provided with an annular groove extending in the axial direction, in which a retaining ring is installed. The retaining ring cooperates with the groove wall of the mounting groove on the piston to limit the position of the flexible sealing ring in the radial direction.

4. The sealing sand control throttle according to claim 3, characterized in that: The retaining ring is in contact with the center tube on one side and in contact with the piston on the other side. The retaining ring and the piston are stopped and cooperated in the direction away from the first joint. When the piston is in contact with the first joint, the retaining ring has a certain distance from the first joint. The side of the retaining ring facing the first joint corresponds to the liquid hole to form a pressure-bearing surface for bearing water pressure.

5. The sealing sand control throttle according to any one of claims 1 to 4, characterized in that: The end surface of the piston in contact with the first joint is a conical surface, the end surface of the flexible sealing ring is an inclined surface matched with the end surface of the piston, and the end surface of the first joint in contact with the piston is an inclined surface matched with the conical surface of the piston.

6. The sealing sand control throttle according to any one of claims 1 to 4, characterized in that: The sealing sand control throttle further comprises a second joint, wherein the first joint is a lower joint and the second joint is an upper joint.

7. The sealed sand control throttle according to claim 6, characterized in that: An adjusting ring is movably mounted on the second joint, and the spring is sleeved on the central tube. The position of the adjusting ring is adjusted relative to the position of the first joint to change the initial compression amount of the spring.

8. The sealed sand control throttle according to claim 7, characterized in that: The adjusting ring is movably mounted on the second joint through threads.

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