Slip type underground throttler and integrated sand prevention fishing device

Abstract

The invention relates to the technical field of throttlers, in particular to a slip type underground throttler and an integrated sand prevention salvage device.The slip type underground throttler comprises a retracting and releasing structure, an end cover, an axis, a slip bowl, a slip body, a center pipe, a cone, a rubber barrel, a baffle ring, a sand prevention mechanism, an adjusting mechanism and a throttling nozzle, and the retracting and releasing structure is located at the rear end of the end cover; the shaft center is located at the center position of the end cover, the slip body is installed at the front end of the slip bowl, the center pipe sequentially penetrates through the rubber sleeve, the cone, the slip body and the slip bowl, the slip bowl is connected with the end cover, the shaft center is located at the center position, the retracting and releasing structure is connected with the shaft center, and the rubber sleeve is arranged on the outer side of the center pipe in a sleeving mode. The baffle ring is installed at the front end of the rubber sleeve, the adjusting mechanism is located on the right side of the baffle ring, the throttling nozzle is located at the front end of the axis, and through three-stage collaborative filtering, the setting effect of the slip is further enhanced while long-term sand prevention is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of restrictors, and more specifically to a slip-type downhole restrictor and an integrated sand control and fishing device. Background Art

[0002] A slip-type downhole restrictor is a downhole tool used in natural gas wells. It is fixed by slipping and anchoring on the inner wall of the tubing, forms a seal in combination with a sealing rubber barrel, and uses a throttle nozzle to reduce the diameter to generate a pressure difference, reduce the wellhead pressure and prevent the formation of hydrates. Its core functions include anchoring, sealing, throttling, and sand control. After it is placed, a fishing device is required for recovery. Sand grains are intercepted through a multi-stage sand control structure (such as a sand control pipe and a lock ring sleeve), and the restrictor is quickly unsealed and fished through mechanisms such as springs and shear pins, avoiding the negative impacts caused by sand plugging or rubber barrel deformation in traditional fishing.

[0003] During the process of being put into use, the restrictor is fixed to the well wall through slips. After long-term use, due to the impact of the fluid flow in the well and the influence of the self-weight of the restrictor, the clamping force at the slips will gradually decrease or even become loose. Moreover, traditional downhole restrictors are prone to low efficiency due to seal failure in a high-pressure difference environment. After seal failure, sand grains in the fluid are likely to invade and cause wear of the restrictor components. For small restrictors, after loosening, they will fall downward and the center will shift, resulting in difficult fishing.

[0004] To solve the above problems, various solutions have been proposed in the prior art, such as increasing the filter screen to improve the filtering effect of sand and gravel. However, since the fluid flows from bottom to top, after long-term impact, the surface of the sand control device is easily blocked or damaged by impact. At this time, sand and gravel will still enter the axial position, further blocking the flow channel and even wearing the components, affecting the normal operation of the restrictor.

[0005] Based on this, in order to solve the problem that it is difficult to calibrate the face cover and the bottom box due to the unfixed shape during the automatic assembly of the infrared detector, the present invention designs a slip-type downhole restrictor and an integrated sand control and fishing device. Summary of the Invention

[0006] The slip-type downhole restrictor and the integrated sand control and fishing device provided by the present invention solve the problem that the restrictor is easily blocked and impacted by sand and gravel during long-term use, thereby affecting the efficiency of the restrictor. By setting three-stage collaborative filtering, while providing long-term sand control, the setting effect of the slips is further enhanced.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A slip-type downhole throttle provided by the present invention includes a retractable structure, an end cap, an axis, a slip seat, a slip body, a central tube, a cone, a rubber cylinder, a retaining ring, a sand control mechanism, an adjustment mechanism, and a throttle nozzle. The retractable structure is located at the rear end of the end cap. The axis is located at the central position of the end cap. The slip body is installed at the front end of the slip seat. The central tube sequentially passes through the rubber cylinder, the cone, the slip body, and the slip seat. The slip seat is connected to the end cap. The axis is located at the central position. The retractable structure is connected to the axis. The rubber cylinder is sleeved outside the central tube. The retaining ring is installed at the front end of the rubber cylinder. The adjustment mechanism is located on the right side of the retaining ring. The throttle nozzle is located at the front end of the axis. The sand control mechanism is installed at the very front end of the axis. When the slip seat pushes the slip body to be fixed, the sand control mechanism drives the adjustment mechanism to drive the retaining ring in the reverse direction, and the retaining ring drives the rubber cylinders to lock each other.

[0009] The sand control mechanism is installed at the lowermost end of the throttle to prevent sand and gravel from flowing upward from the axis. At the same time, the sand control mechanism cooperates with the adjustment mechanism to further fix and seal the throttle under long-term use and rapid impact of substances, thereby improving the use efficiency of the throttle. The throttle nozzle is used for the flow of substances, and a certain pressure difference is formed above and below the throttle nozzle, and the pressure difference makes the throttle seat seal more firmly.

[0010] Preferably, the retractable structure includes a dropping head, a fishing head, a dropping pin, and a connecting head. The dropping head and the fishing head are both installed at the front end of the axis. The dropping pin is installed between the dropping head and the fishing head. The connecting head is located at the dropping pin.

[0011] By rotating the rope, the dropping head rotates relative to the connecting head and then disengages along the dropping pin, achieving the effect of convenient installation and disengagement.

[0012] Preferably, the sand control mechanism includes a transition sleeve, a lock ring sleeve, a sand control pipe, and a spiral blade. The transition sleeve is installed at the front end of the retaining ring. The lock ring sleeve is installed between the retaining ring and the transition sleeve. The sand control pipe is installed at the front end of the axis. The spiral blade is installed inside the sand control pipe.

[0013] On the one hand, it reduces the direct impact of sand and gravel on the sand control pipe, thereby avoiding damage to the sand control pipe. It only needs to replace the spiral blade at that time. On the other hand, it can guide the path of sand and gravel to avoid sand and gravel accumulation at the sand control pipe, thereby affecting the normal transmission of fluid, and thus ensuring the stability of the throttle.

[0014] Preferably, the front end of the sand control pipe is conical, and a mud guard is installed inside the sand control pipe.

[0015] After the fluid passes through the spiral blades, the liquid can flow toward the fender under the action of pressure difference. At the same time, the sand and gravel will flow upward along the edge of the fender, and then move upward along the side wall of the axis, and then reach the transition sleeve. Under the action of long-term accumulation, it can gradually form an obstruction, further ensuring that the slip body and the rubber cylinder will not reset, thereby improving the use efficiency of the throttle.

[0016] Preferably, the adjustment mechanism includes a slide groove, a wedge block, and an extrusion block. The slide groove is opened in the transition sleeve, the wedge block is installed in the slide groove, the extrusion block is located at the front end of the locking ring sleeve, and the extrusion block is provided with an inclined surface on the side facing the wedge block.

[0017] The extrusion ring slides outward and fits with the edges of the locking ring sleeve and the transition sleeve, thereby forming a seal and improving the connection strength between the two, thereby improving the stability of the throttle.

[0018] Preferably, a limiting ring is provided between the slip seat and the slip body, and the cross section of the limiting ring is I-shaped.

[0019] During the repeated lifting process, the slip body and the limiting ring collide repeatedly, which can make the limiting ring gradually embedded in the gaps of the slip body, thereby improving the fixing effect of the slip body on the side wall.

[0020] Preferably, the number of the rubber cylinders is two, and mutually staggered protrusions are provided on opposite surfaces of the two rubber cylinders.

[0021] When the rubber sleeve extends outward to achieve sealing, the offset protrusions on the two corresponding surfaces can fit into each other, thereby forming radial fixation.

[0022] An integrated sand control and salvage device, which is suitable for any of the above-mentioned slip-body downhole chokes, includes a casing, a pawl and a return spring are provided in the casing, the pawls are arranged in an annular array on the inside of the casing, the return spring is located between the pawl and the casing, and the end of the salvage head is provided with a clamping portion, which fits with the pawl.

[0023] When salvage is required, the salvage head is gradually wrapped by the casing. Then, under the action of the pawl and the return spring, the clamping part on the salvage head passes the pawl, and the pawl reversely locks the salvage head. At this time, when the casing moves upward, the pawl will drive the salvage head to move upward, thereby achieving salvage.

[0024] The beneficial effects of the present invention are as follows:

[0025] 1. The present invention proposes a slip-type downhole choke, in which a sand prevention mechanism is installed at the lowest end of the choke to prevent sand and gravel from flowing upward from the axis. At the same time, the sand prevention mechanism cooperates with the adjustment mechanism to further fix and seal the choke under long-term use and rapid impact of materials, thereby improving the use efficiency of the choke.

[0026] 2. A slip-type downhole throttle proposed by the present invention, during the process of fluid flowing from bottom to top, it will first pass through the spiral blades. At this time, the spiral blades will block the impact of the fluid on the sand control pipe, and at the same time, they will also guide the sand and gravel to flow along the spiral blades to both sides. On the one hand, it reduces the direct impact of the sand and gravel on the sand control pipe, thus avoiding damage to the sand control pipe. Only the spiral blades need to be replaced at that time. On the other hand, it can guide the path of the sand and gravel, avoiding the accumulation of sand and gravel at the sand control pipe, thus affecting the normal transmission of the fluid. Under the action of the spiral blades, the sand and gravel carried in the fluid will flow along the path of the spiral blades to the side wall of the sand control pipe, thus forming a filling.

[0027] 3. A slip-type downhole throttle proposed by the present invention, through the three-stage collaborative filtering structure of the sand control pipe, the lock ring sleeve, and the retaining ring, the sand and gravel gradually reach the inclined plane position of the extrusion block, thereby pushing the extrusion block. And the extrusion block moves radially, so it will push the extrusion block to move outwards. Thus, under the lateral extrusion, the compaction effect of the sand and gravel at the extrusion block is improved, and its friction force is increased. And the radially moving extrusion block will gradually push the wedge block, thereby driving the wedge block to move upwards gradually, so that the wedge block abuts against the lock ring sleeve. On the other hand, the extrusion ring slides outwards and will fit with the edges of the lock ring sleeve and the transition sleeve. Thus, while forming a seal, it also improves the connection strength between the two, and further improves the stability of the throttle. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are one embodiment of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0029] Figure 1 is the overall view of the throttle of the present invention;

[0030] Figure 2 is the semi-sectional schematic view of the throttle of the present invention;

[0031] Figure 3 is Figure 2 the enlarged view of part A in

[0032] Figure 4 is Figure 2 the enlarged view of part B in

[0033] Figure 5 is Figure 2 the enlarged view of part C in

[0034] Figure 6 is Figure 2Enlarged view at D in [the figure];

[0035] Figure 7 is Figure 2 Enlarged view at E in [the figure];

[0036] Figure 8 is a schematic diagram of the sand control mechanism of the present invention;

[0037] Figure 9 is Figure 8 Enlarged view at F in [the figure];

[0038] Figure 10 is a schematic diagram of the adjustment mechanism of the present invention;

[0039] Figure 11 is a schematic diagram of the fishing device of the present invention.

[0040] In the figure: 1. Reeling-in and paying-out structure; 101. Delivery head; 102. Fishing head; 1021. Clamping part; 103. Delivery pin; 104. Connector; 2. End cover; 3. Axis; 4. Slip seat; 5. Slip body; 6. Central tube; 7. Cone; 8. Rubber cylinder; 81. Protrusion; 9. Retaining ring; 11. Sand control mechanism; 111. Transition sleeve; 112. Locking ring sleeve; 113. Sand control pipe; 1131. Mud guard; 114. Helical blade; 12. Adjustment mechanism; 121. Slide groove; 122. Wedge block; 123. Extrusion block; 1231. Inclined surface; 13. Limiting ring; 14. Unsealing shear pin; 15. Casing; 16. Pawl; 17. Return spring; 18. Throttle nozzle. Detailed implementation manner

[0041] In order to better understand the above solutions, the above technical solutions will be described in detail below in conjunction with the accompanying drawings of the specification and the specific implementation manners.

[0042] Such as Figure 1 、 2As shown in the figure, a slip-type downhole choke provided by the present invention includes a retracting and deploying structure 1, an end cap 2, an axis 3, a slip seat 4, a slip body 5, a central tube 6, a cone 7, a rubber barrel 8, a retaining ring 9, a sand control mechanism 11, an adjustment mechanism 12, and a choke nozzle 18. The retracting and deploying structure 1 is located at the rear end of the end cap 2. The axis 3 is located at the central position of the end cap 2. The slip body 5 is installed at the front end of the slip seat 4. The central tube 6 passes through the rubber barrel 8, the cone 7, the slip body 5, and the slip seat 4 in sequence. The slip seat 4 is connected to the end cap 2. The axis 3 is located at the central position. The retracting and deploying structure 1 is connected to the axis 3. The rubber barrel 8 is sleeved outside the central tube 6. The retaining ring 9 is installed at the front end of the rubber barrel 8. The adjustment mechanism 12 is located on the right side of the retaining ring 9. The choke nozzle 18 is located at the front end of the axis 3. The sand control mechanism 11 is installed at the frontmost end of the axis 3. When the slip seat 4 pushes the slip body 5 to be fixed, the sand control mechanism 11 drives the adjustment mechanism 12 to drive the retaining ring 9 in the reverse direction, and the retaining ring 9 drives the rubber barrel 8 to be locked with each other.

[0043] The retracting and deploying structure 1 is used to drive the slip-type choke to rise and fall, so as to meet the placement and extraction of the choke. The axis 3 is a hollow structure, which can realize the flow of substances, so as to realize the throttling of substances. During the placement process, the retracting and deploying structure 1 drives the axis 3 to move downward, thereby driving the central tube 6 and the cone 7, etc. to move downward. However, at this time, the end cap 2, the slip seat 4, and the slip body 5 are affected by gravity and will move downward, and the relative moving distance is greater than that of the cone 7. Therefore, the distance between the slip body 5 and the cone 7 is further reduced. When reaching the pre-installed position, quickly lift the retracting and deploying structure 1 at this time, thereby driving the rubber barrel 8, the cone 7, etc. to move upward instantaneously, so as to form a relative movement with the slip body 5, and then drive the slip body 5 to be squeezed. After repeated squeezing for many times, at this time, the slip body 5 is gradually clamped on the outside, so as to form the fixation of the overall choke. After the slip body 5 is clamped, at this time, the cone 7 synchronously squeezes the rubber barrel 8, and then, in cooperation with the retaining ring 9, the rubber barrel 8 is pushed upward, so as to expand outward and form a seal for the outside, avoiding the outflow from the outside when substances flow, and then reducing the efficiency of the choke.

[0044] The sand control mechanism 11 is installed at the lowermost end of the choke, and is used to prevent sand and gravel from flowing upward from the axis 3. At the same time, the sand control mechanism 11 cooperates with the adjustment mechanism 12 to further fix and seal the choke under long-term use and rapid impact of substances, so as to improve the use efficiency of the choke. The choke nozzle 18 is used for the flow of substances. A certain pressure difference is formed above and below the choke nozzle 18, and the pressure difference makes the choke seat seal more firmly.

[0045] As Figure 1 、 2As shown, the retracting and deploying structure 1 includes a delivery head 101, a fishing head 102, a delivery pin 103, and a connecting head 104. The delivery head 101 and the fishing head 102 are both installed at the front end of the axis 3. The delivery pin 103 is installed between the delivery head 101 and the fishing head 102, and the connecting head 104 is located at the position of the delivery pin 103.

[0046] A rope is installed above the delivery head 101. The delivery head 101 is suspended downward by the rope, and then drives the delivery pin 103 and the connecting head 104 to drive the axis 3 to move synchronously. The delivery pin 103 is used for rotational fixation. Initially, the rope above is rotated, causing the delivery head 101 to drive the delivery pin 103 to rotate, so that the delivery head 101 engages with the connecting head 104. The delivery head 101 is driven downward by the rope, thereby driving the entire throttle valve downward. When the throttle valve is fixed and sealed, by rotating the rope, the delivery head 101 rotates relative to the connecting head 104 and then disengages along the delivery pin 103, achieving the effect of convenient installation and disengagement.

[0047] As Figure 2 、 3 As shown in Figures 4, 5, and 10, the sand control mechanism 11 includes a transition sleeve 111, a lock ring sleeve 112, a sand control pipe 113, and a spiral blade 114. The transition sleeve 111 is installed at the front end of the retaining ring 9. The lock ring sleeve 112 is installed between the retaining ring 9 and the transition sleeve 111. The sand control pipe 113 is installed at the front end of the axis 3, and the spiral blade 114 is installed inside the sand control pipe 113.

[0048] During the process of fluid flowing upward from bottom to top, it will first pass through the spiral blade 114. At this time, the spiral blade 114 will block the impact of the fluid on the sand control pipe 113, and at the same time, it will also guide the sand and gravel to flow to both sides along the spiral blade 114. On the one hand, it reduces the direct impact of the sand and gravel on the sand control pipe 113, thereby avoiding damage to the sand control pipe 113. It only needs to replace the spiral blade 114 at that time. On the other hand, it can guide the path of the sand and gravel to avoid the accumulation of sand and gravel at the sand control pipe 113, thereby affecting the normal transmission of the fluid. Under the action of the spiral blade 114, the sand and gravel carried in the fluid will flow along the path of the spiral blade 114 to the side wall of the sand control pipe 113, thus forming a filling. On this basis, if the gravity of the sand and gravel is less than the flow force of the water flow, the sand and gravel can be located at that place and can push the small throttle valve to a certain extent. This is for the small throttle valve with a diameter of about dozens of millimeters. For the large throttle valve, although it cannot play a pushing role, it can gradually increase the filling over time, thereby ensuring the stability of the throttle valve.

[0049] As Figure 2 、 7 As shown in Figures 8 and 9, the front end of the sand control pipe 113 is conical, and a mud guard 1131 is installed inside the sand control pipe 113.

[0050] The mudguard 1131 here further protects the axis 3 to prevent sand and gravel from entering. At the same time, the mudguard 1131 is perpendicular to the axis of the axis 3 and tangent to the spiral line of the spiral blade 114. After the fluid passes through the spiral blade 114, the liquid can flow toward the mudguard 1131 under the action of the pressure difference. At the same time, the sand and gravel will flow upward along the edge of the mudguard 1131, thereby moving upward along the side wall of the axis 3 and reaching the transition sleeve 111. Under the action of long-term accumulation, a barrier can be gradually formed. After long-term use, when the cava body 5 is worn, the transition sleeve 111 at the bottom will provide an upward extrusion force, thereby further ensuring that the cava body 5 and the rubber cylinder 8 will not reset, thereby improving the use efficiency of the throttle.

[0051] like Figure 2 、 6 As shown, the adjustment mechanism 12 includes a slide groove 121, a wedge block 122, and an extrusion block 123. The slide groove 121 is opened in the transition sleeve 111, the wedge block 122 is installed in the slide groove 121, and the extrusion block 123 is located at the front end of the locking ring sleeve 112. The extrusion block 123 is provided with an inclined surface 1231 on the side facing the wedge block 122.

[0052] As the sand and gravel flow upward, they will gradually reach the inclined surface 1231 of the extrusion block 123, thereby pushing the extrusion block 123. The extrusion block 123 moves radially, so it will push the extrusion block 123 to move outward, thereby improving the compaction effect of the sand and gravel at the extrusion block 123 under lateral extrusion, and increasing its friction. The radially moving extrusion block 123 will gradually push the wedge block 122, thereby driving the wedge block 122 gradually upward, so that the wedge block 122 is pressed against the locking ring sleeve 112. On the other hand, the extrusion ring slides outward and fits with the edges of the locking ring sleeve 112 and the transition sleeve 111, thereby forming a seal and improving the connection strength between the two, thereby improving the stability of the throttle.

[0053] like Figure 2 As shown, a limiting ring 13 is provided between the slip seat 4 and the slip body 5 , and the cross section of the limiting ring 13 is an I-shape.

[0054] The limiting ring 13 is used to protect and fix the cava body 5. When the whole is placed downward, the cava seat 4 will drive the cava body 5 downward, and then under the action of gravity, the cava seat 4 will slide downward toward the limiting ring 13, and then push the cava body 5, and then extract the delivery head 101 upward. Under repeated action, the cava seat 4 and the cava body 5 will be gradually driven to be squeezed. At this time, the limiting ring 13 forms a fixing and protective effect, which further pushes the cava body 5. At the same time, it can be hard rubber, which can be deformed when the pressure is large enough. Then, in the process of repeated lifting, the cava body 5 and the limiting ring 13 repeatedly collide, which can make the limiting ring 13 gradually embedded in the gap between the cava body 5, thereby improving the fixing effect of the cava body 5 on the side wall.

[0055] like Figure 2 、 4 As shown in FIG. 5 , there are two rubber tubes 8 , and mutually staggered protrusions 81 are provided on opposite sides of the two rubber tubes 8 .

[0056] When the rubber sleeve 8 extends outward to achieve sealing, the rubber sleeve 8 expands in the radial direction of the axis. When the rubber sleeve 8 expands, the offset protrusions 81 on the two corresponding surfaces can fit together to form a radial fixation, which can resist part of the gravity and thus improve the sealing effect of the rubber sleeve 8. An unsealing shear pin 14 is installed between the slip seat 4 and the fishing head 102.

[0057] like Figure 1 、 2 11, an integrated sand control and salvage device is suitable for any of the above-mentioned slip body 5-type downhole chokes, including a casing 15, wherein a pawl 16 and a return spring 17 are provided in the casing 15, the pawl 16 is arranged in a circular array on the inner side of the casing 15, and the return spring 17 is located between the pawl 16 and the casing 15, and the end of the salvage head 102 is provided with a clamping portion 1021, and the clamping portion 1021 fits with the pawl 16.

[0058] When salvaging is required, the salvaging head 102 is gradually wrapped by the sleeve 15. Then, under the action of the pawl 16 and the return spring 17, the clamping portion 1021 on the salvaging head 102 passes over the pawl 16, and the pawl 16 reversely locks the salvaging head 102. At this time, when the sleeve 15 moves upward, the pawl 16 will drive the salvaging head 102 to move upward, thereby achieving salvage.

[0059] During the deployment phase, the staff connects the choke with a tool (such as a rope) and places it into the well. Before the seal is set, the deployment tool is connected to the choke via the deployment pin 103. The slips are now relaxed and the sealing rubber sleeve 8 is in a naturally contracted state.

[0060] Setting stage: By repeatedly lifting the wire rope to a preset tension, the retracting and releasing structure 1 drives the slip-type throttle valve to rise and fall. The retracting and releasing structure 1 drives the shaft center 3 to move downward, thereby driving the central tube 6, the cone 7, etc. to move downward. However, at this time, the end cap 2, the slip seat 4 and the slip body 5 are affected by gravity and will move downward, and the relative moving distance is greater than that of the cone 7. Thus, the distance between the slip body 5 and the cone 7 is further reduced. After the throttle valve reaches the predetermined position, wait for a few minutes, record the tension value, and then quickly lift. The tension gauge value rises. Continue to lift the wire rope and control the tension value. Repeat the operations of lowering and lifting. Pay attention to the change of the tension gauge value when lowering. The throttle valve is released by repeatedly shocking through lifting and lowering. At this time, the rubber barrel 8, the cone 7, etc. move upward instantaneously, thus forming a relative movement with the slip body 5, and then driving the slip body 5 to be extruded. After being extruded repeatedly for many times, the slip body 5 is gradually clamped on the outside, thus fixing the overall throttle valve. The dropping head 101 is driven to move downward by the wire rope, thereby driving the entire throttle valve to move downward. When the throttle valve is fixed and sealed, by rotating the wire rope, the dropping head 101 rotates relative to the connector 104, and then disengages along the dropping pin 103. Along with the upward movement of the wire rope operation, only the dropping head 101 is lifted out of the wellbore, and the rest of the throttle valve remains in the wellbore. The throttle valve setting is successful. A certain pressure difference is formed above and below the throttle nozzle 18, and the pressure difference makes the setting of the throttle valve more reliable;

[0061] Fishing stage: The dropping tool is replaced with a fishing tool. The tool string is connected and lowered into the well. The fishing head 102 is gradually wrapped by the casing 15. Subsequently, under the action of the pawl 16 and the return spring 17, the clamping part 1021 on the fishing head 102 passes over the pawl 16, and the pawl 16 locks the fishing head 102 in the reverse direction. At this time, when the casing 15 moves upward, the pawl 16 will drive the fishing head 102 to move upward. The unsealing shear pin 14 is cut off under the pulling force. Continue to lift to loosen the slip and the cone 7. At the same time, the sealing rubber barrel 8 shrinks. Then continue to lift to lift out the downhole throttle valve.

[0062] The above shows and describes the basic principles and beneficial effects of the present invention. At the same time, the present invention is not limited by the above embodiments. Without departing from the effects and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A slip-type downhole choke, characterized by: It includes a retractable structure (1), an end cap (2), an axis (3), a slip seat (4), a slip body (5), a central tube (6), a cone (7), a rubber cylinder (8), a retaining ring (9), a sand control mechanism (11), an adjusting mechanism (12) and a choke nozzle (18). The retractable structure (1) is located at the rear end of the end cap (2). The axis (3) is located at the central position of the end cap (2). The slip body (5) is installed at the front end of the slip seat (4). The central tube (6) is sequentially arranged through the rubber cylinder (8), the cone (7), the slip body (5) and the slip seat (4). The slip seat (4) is connected to the end cap (2). The axis (3) is located at the central position. The retractable structure (1) is connected to the axis (3). The rubber cylinder (8) is sleeved outside the central tube (6). The retaining ring (9) is installed at the front end of the rubber cylinder (8). The adjusting mechanism (12) is located on the right side of the retaining ring (9). The choke nozzle (18) is located at the front end of the axis (3). The sand control mechanism (11) is installed at the foremost end of the axis (3). When the slip seat (4) pushes the slip body (5) to be fixed, the sand control mechanism (11) drives the adjusting mechanism (12) to drive the retaining ring (9) in the reverse direction, and the retaining ring (9) drives the rubber cylinders (8) to lock each other.

2. The slip-type downhole choker according to claim 1, characterized in that: The retractable structure (1) includes a dropping head (101), a fishing head (102), a dropping pin (103) and a connecting head (104). The dropping head (101) and the fishing head (102) are both installed at the front end of the axis (3). The dropping pin (103) is installed between the dropping head (101) and the fishing head (102). The connecting head (104) is located at the position of the dropping pin (103).

3. The slip-type downhole choke according to claim 1, characterized in that: The sand control mechanism (11) includes a transition sleeve (111), a lock ring sleeve (112), a sand control pipe (113) and a spiral blade (114). The transition sleeve (111) is installed at the front end of the retaining ring (9). The lock ring sleeve (112) is installed between the retaining ring (9) and the transition sleeve (111). The sand control pipe (113) is installed at the front end of the axis (3). The spiral blade (114) is installed inside the sand control pipe (113).

4. A slip-type downhole choke according to claim 3, characterized in that: The front end of the sand control pipe (113) is conical, and a mud guard (1131) is installed inside the sand control pipe (113).

5. The slip-type downhole choke according to claim 3, characterized in that: The adjusting mechanism (12) includes a chute (121), a wedge block (122), and an extrusion ring (123). The chute (121) is opened in the transition sleeve (111). The wedge block (122) is installed in the chute (121). The extrusion ring (123) is located at the front end of the lock ring sleeve (112), and a slope (1231) is provided on one side of the extrusion ring (123) facing the wedge block (122).

6. The slip-type downhole choke according to claim 1, characterized in that: A limit ring (13) is provided between the slip seat (4) and the slip body (5), and the cross-section of the limit ring (13) is I-shaped.

7. The slip-type downhole choke according to claim 1, characterized in that: The number of the rubber cylinders (8) is two, and the opposite sides of the two rubber cylinders (8) are provided with staggered protrusions (81).

8. The slip-type downhole choke according to claim 6, characterized in that: A releasing shear pin (14) is installed between the slip seat (4) and the fishing head (102).

9. An integrated sand control and salvage device, adapted for use with any of the slip-type downhole chokes described in 1-8 above, characterized in that: It includes a casing (15) in which a pawl (16) and a return spring (17) are provided. The pawls (16) are annularly arrayed on the inner side of the casing (15), and the return spring (17) is located between the pawl (16) and the casing (15). A clamping portion (1021) is provided at the end of the fishing head (102), and the clamping portion (1021) is engaged with the pawl (16).

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