Air-tight seal buckle structure of oil casing

Abstract

The invention relates to the technical field of sleeve joint structures, and discloses an oil sleeve air-tight seal buckle structure which comprises two oil sleeve bodies and a joint pipe fitting, external threads are arranged on the outer sides of the connecting ends of the two oil sleeve bodies, and internal threads matched with the external threads are arranged on the inner sides of the two ends of the joint pipe fitting. After the opposite end faces of the two oil casing bodies abut against each other, the oil casing further comprises port clamping pieces detachably arranged at the two ends of the connector pipe fitting. According to the air-tight seal buckle structure of the oil sleeve, the port clamping pieces generate fastening force when being installed at the two ends of the connector pipe fitting, the end of the oil sleeve body is further fastened, and axial relative sliding between the oil sleeve body and the connector pipe fitting is limited. In the installation process of the port clamping piece, the load sharing piece is driven to move in the radial direction of the oil sleeve body and abut against the peripheral wall of the oil sleeve body, an auxiliary supporting structure is formed between the peripheral wall of the oil sleeve body and the inner wall of the connector pipe fitting, and stress concentration of threads on the oil sleeve body and the connector pipe fitting is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of casing joint structure, and particularly relates to a casing and tubing gas seal buckle structure. BACKGROUND

[0002] The casing and tubing gas seal is a core technology for ensuring the integrity of the wellbore in the oil and gas well engineering, and the core goal is to realize the gas seal of the pipe string under the complex conditions of high pressure, high temperature and corrosion by the special design of the gas seal buckle structure of the casing joint, the precise structure and the material optimization, and the strict compliance with the makeup process.

[0003] At present, the existing casing and tubing gas seal buckle structure is improved by the thread profile, so as to improve the sealing performance between the casing and the joint pipe, but in the actual use process of the casing, the casing is also subjected to various dynamic loads during oil production, and under the long-time working condition, the vibration or alternating load causes the axial relative sliding of the thread contact surface to the thread galling, the surface oxide layer is damaged, the intermetallic direct friction is formed, the abrasion is accelerated, the gap is generated at the thread sealing position, and the leakage phenomenon occurs. SUMMARY

[0004] In view of the above-mentioned defects in the prior art, the present application provides a casing and tubing gas seal buckle structure, which can effectively solve the problem that under the long-time working condition, the vibration or alternating load causes the axial relative sliding of the thread contact surface to the thread galling, the surface oxide layer is damaged, the intermetallic direct friction is formed, the abrasion is accelerated, the gap is generated at the thread sealing position, and the leakage phenomenon occurs. TECHNICAL SCHEME

[0005] In order to achieve the above-mentioned purpose, the present application is realized by the following technical scheme: The present application provides a casing and tubing gas seal buckle structure, which comprises two casing main bodies and a joint pipe, the outer side of the connecting end of the two casing main bodies is provided with an external thread, the inner side of the two ends of the joint pipe is provided with an internal thread matched with the external thread, when the opposite end faces of the two casing main bodies abut against each other, the joint pipe is used for sleeving on the two casing main bodies, and further comprises: The port clamping piece is detachably arranged at the two ends of the joint pipe, and the port clamping piece is used for further fastening the end portion of the casing main body; The load sharing piece is arranged on the inner side of the port clamping piece, and the load sharing piece is used for reducing the stress concentration of the thread on the casing main body and the joint pipe; During the process of installing the port adapter on the joint pipe, the driving load sharing member moves along the radial direction of the oil casing body and abuts against the outer peripheral wall of the oil casing body to form an auxiliary support structure between the outer peripheral wall of the oil casing body and the inner wall of the joint pipe.

[0006] Further, the port adapter comprises a necking sleeve arranged at the end of the joint pipe, the wall of the necking sleeve gradually reduces in diameter from the side close to the joint pipe to the distal end, and the minimum inner diameter of the necking sleeve is equal to the diameter of the oil casing body. The outer side of the necking sleeve is threadedly connected with a locking ring, the inner diameter of the locking ring is consistent with the matching size of the outer taper surface of the necking sleeve, the necking sleeve is radially contracted by the contact of the outer taper surface when the locking ring is screwed, and an anti-skid pad is arranged on the inner side wall of the necking sleeve.

[0007] Further, the opposite end faces of the two oil casing bodies are each provided with a sealing groove, and the two sealing grooves are arranged staggered with each other, and each of the sealing grooves is provided with a hollow sealing ring. Further, the outer circumferential surface of the locking ring is provided with knurling.

[0008] Further, the load sharing member comprises a sliding ring arranged on the outer side of the joint pipe, and the inner diameter of the sliding ring is smaller than the outer diameter of the locking ring, the outer wall of the joint pipe is provided with a sliding groove for the axial movement of the sliding ring, a plurality of insertion rods are movably and penetratively arranged on the wall of the joint pipe, and the wall of the joint pipe is provided with a perforation matched with the insertion rods.

[0009] Further, the number of the insertion rods is not less than two, and one end of the insertion rod is provided with a wedge, and the wedge is located on the outer side of the joint pipe. When the sliding ring moves to the middle part of the joint pipe, the wall of the sliding ring extrudes the inclined surface of the wedge, and the wedge drives the insertion rod to move to the inner side of the joint pipe.

[0010] Further, a limiting ring is sleeved on the insertion rod, a first spring is sleeved on the insertion rod, the two ends of the first spring are respectively abutted against the opposite faces of the joint pipe and the limiting ring, a piston is slidably connected in the perforation, one end of a sliding rod connected with the piston is connected with the other end of the sliding rod, the other end of the sliding rod is slidably connected in the insertion rod, a second spring is sleeved on the sliding rod, the two ends of the second spring are respectively abutted against the opposite faces of the insertion rod and the piston, an air cavity is formed between the upper surface of the piston and the lower surface of the insertion rod, an air channel is arranged in the oil casing body, one end of the air channel is communicated with the air cavity, and the other end of the air channel is communicated with the corresponding hollow sealing ring.

[0011] Further, two said sliding rings are provided with locking plates on the side close to each other, the locking plate comprises a plug-in strip connected with the outer wall of the sliding ring, and the plug-in strip is made of elastic material, and the end of the plug-in strip is integrally provided with a clamping block.

[0012] Further, the clamping block is in the shape of a trapezoidal convex structure with an inclined surface, and the inclination angle of the inclined surface of the clamping block is greater than 90 degrees.

[0013] Further, the number of the locking plates is not less than two, and the wall of the joint pipe is provided with an L-shaped slot for inserting the locking plate.

[0014] 1. In the present application, when the port clamping piece is installed at both ends of the joint pipe, a fastening force is generated to further fasten the end of the oil sleeve body and limit the axial relative sliding between the oil sleeve body and the joint pipe. During the installation of the port clamping piece, the driving load sharing piece moves radially along the oil sleeve body and abuts against the outer peripheral wall thereof, thereby forming an auxiliary support structure between the outer peripheral wall of the oil sleeve body and the inner wall of the joint pipe, and reducing the stress concentration of the threads on the oil sleeve body and the joint pipe. The two work together to reduce the thread galling and wear caused by vibration or alternating load, and avoid the generation of gaps in the threaded sealing part to prevent leakage.

[0015] 2. In the present application, the wall of the closing sleeve gradually reduces in diameter from the side close to the joint pipe to the distal end, so that the contraction force can uniformly act on the end of the oil sleeve body, thereby further clamping the oil sleeve body. The anti-skid pad fixedly installed or bonded on the inner wall of the closing sleeve increases the friction force between the oil sleeve body and the closing sleeve during the clamping of the closing sleeve on the oil sleeve body, thereby effectively preventing the relative sliding between the oil sleeve body and the closing sleeve.

[0016] 3. In the present application, when the clamping block is inserted into the L-shaped slot, the inclined surface with an inclination angle greater than 90 degrees generates greater friction force and engagement force between the inclined surface and the wall of the L-shaped slot when the clamping block is subjected to the axial tension along the wall of the L-shaped slot. Because the inclination angle is large, the component of the tension in the direction perpendicular to the inclined surface is larger, thereby increasing the pressure between the clamping block and the wall of the slot. The increase in pressure increases the friction force, which effectively prevents the clamping block from being loosened from the L-shaped slot, thereby ensuring the locking effect of the locking plate on the sliding ring and ensuring the stable operation of the load sharing piece. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0018] Figure 1 Figure 1 is a schematic view of the installation of the oil casing body according to an embodiment of the present application; Figure 2 Figure 2 is a schematic view of the structure of the joint pipe according to an embodiment of the present application; Figure 3 Figure 3 is a schematic view of the partial cross-sectional structure according to an embodiment of the present application; Figure 4 Figure 4 is a schematic view of the structure of the joint pipe according to an embodiment of the present application; Figure 1 Figure 5 is a schematic view of the structure of the joint pipe according to an embodiment of the present application; Figure 5 Figure 6 is a schematic view of the structure of the joint pipe according to an embodiment of the present application; Figure 3 Figure 7 is a schematic view of the structure of the joint pipe according to an embodiment of the present application; Figure 6 Figure 8 is a schematic view of the structure of the sliding ring according to an embodiment of the present application; Figure 7 Figure 9 is a schematic view of the installation of the locking plate according to an embodiment of the present application; Figure 8 Figure 10 is a state change diagram of the piston according to an embodiment of the present application.

[0019] In the figures, the reference numbers represent: 100, oil casing body; 110, sealing groove; 200, joint pipe; 300, port clamping member; 301, closing clamp; 302, locking ring; 303, non-slip pad; 400, load sharing member; 401, sliding ring; 402, sliding groove; 403, insertion rod; 404, perforation; 405, wedge block; 406, limiting ring; 407, first spring; 408, locking plate; 4081, insertion strip; 4082, clamping block; 409, L-shaped groove; 4010, sliding rod; 4011, piston; 4012, second spring; 500, hollow sealing ring. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme of the embodiments of the present application will be described clearly and completely below in combination with the drawings of the embodiments of the present application. Obviously, the described embodiments are some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0021] The present application will be further described below in combination with the embodiments.

[0022] Embodiment 1, refer to Figures 1-3For the first embodiment of the present application, an oil casing gas seal buckle structure is provided, comprising two oil casing bodies 100 and a joint pipe 200, the outer side of the connecting end of the two oil casing bodies 100 is provided with external threads, and the inner side of the two ends of the joint pipe 200 is provided with internal threads matched with the external threads, and when the opposite end faces of the two oil casing bodies 100 abut against each other, the joint pipe 200 is used to be sleeved on the two oil casing bodies 100.

[0023] At present, the existing oil casing body 100 and joint pipe 200 installation are all through improving the thread tooth type, thereby improving the sealing performance between the oil casing body 100 and the joint pipe 200, but in the actual use process of the oil casing body 100, due to the oil casing body 100 also being subjected to various dynamic loads during oil extraction, under the long-time working state, the vibration or alternating load makes the threaded contact surface produce axial relative sliding to the thread galling, causes the surface oxide layer of the oil casing body 100 and the joint pipe 200 to be damaged, the metal direct friction, forms the grinding dust and accelerates the wear, and causes the gap to occur and leak at the threaded sealing position.

[0024] The present application also includes: a port clamping piece 300 which is detachably installed at the two ends of the joint pipe 200, and is used for further fastening the end part of the oil casing body 100; and a load sharing piece 400 which is installed at the inner side of the port clamping piece 300 and is used for reducing the stress concentration of the threads on the oil casing body 100 and the joint pipe 200.

[0025] In the process of integrally installing the port clamping piece 300 on the joint pipe 200, the driving load sharing piece 400 moves along the radial direction of the oil casing body 100 and abuts against the outer peripheral wall of the oil casing body 100, so as to form an auxiliary support structure between the outer peripheral wall of the oil casing body 100 and the inner wall of the joint pipe 200.

[0026] Specifically, the port clamping piece 300 can be composed of a split clamp and a wedge-shaped lock ring, the inner surface of the split clamp is sprayed with a wear-resistant coating such as a tungsten carbide coating with a thickness of 50-100 μm and a friction coefficient ≤0.15, so as to avoid damaging the surface of the oil casing when clamping; the split clamp is made of two semicircular clamps made of high-strength alloy steel, the inner side is provided with a groove matched with the outer wall of the oil casing body 100, and the semicircular clamps are connected into a ring through bolts to provide radial clamping force, and the outer side of the split clamp is provided with a tapered thread matched with the inner tapered surface of the wedge-shaped lock ring, so that when the wedge-shaped lock ring is tightened, an axial component force is generated, which is converted into radial clamping force to enhance the fastening effect.

[0027] Specifically, the load sharing member 400 can be a pin made of high-strength alloy steel. The pin is inserted perpendicular to the axis of the casing body 100, with a diameter of 10-20 mm and a length covering the casing wall thickness + joint gap, to bear the radial shear force between the casing body 100 and the joint pipe 200 and reduce the thread root stress.

[0028] Specifically, the port clamping member 300 generates a fastening force when installed at both ends of the joint pipe 200, further fastening the end of the casing body 100 and limiting the axial relative sliding between the casing body 100 and the joint pipe 200. During the installation of the port clamping member 300, the driving load sharing member 400 moves radially along the casing body and abuts against the outer peripheral wall, forming an auxiliary support structure between the outer peripheral wall of the casing body 100 and the inner wall of the joint pipe 200, reducing the stress concentration of the threads on the casing body 100 and the joint pipe 200. The two work together to reduce thread galling and wear caused by vibration or alternating load, and avoid leakage caused by gaps in the threaded seal area.

[0029] Embodiment 2, refer to Figures 1-2 As a second embodiment of the present application, the difference between this embodiment and the first embodiment is that the port clamping member 300 includes a conical sleeve 301 slidingly connected to the end of the joint pipe 200. The wall of the conical sleeve 301 gradually reduces in diameter from the side close to the joint pipe 200 to the distal end, and the minimum inner diameter of the conical sleeve 301 is equal to the diameter of the casing body 100. An anti-slip pad 303 is fixedly installed or bonded on the inner side wall of the conical sleeve 301.

[0030] The outer side of the conical sleeve 301 is threadedly connected with a locking ring 302, and the inner diameter of the locking ring 302 is consistent with the mating size of the outer taper surface of the conical sleeve 301. The outer circumferential surface of the locking ring 302 is provided with knurling, which facilitates the tightening of the conical sleeve 301 by the locking ring 302 to limit the casing body 100. When the locking ring 302 is tightened, it is in contact with the outer taper surface of the conical sleeve 301, causing it to contract radially.

[0031] Specifically, when the port card connector 300 needs to be installed, first, the connecting end of the oil casing body 100 is inserted into the close-in sleeve 301 at the end of the joint pipe 200, and then the oil casing body 100 or the joint pipe 200 is rotated, so that the oil casing body 100 and the joint pipe 200 are screwed and connected. Since the minimum inner diameter of the close-in sleeve 301 is equal to the diameter of the oil casing body 100, in the initial state, due to the friction and the screwing mode, the two are in a relatively tight fit. Then, the operator rotates the locking ring 302 by manually or using a tool such as a wrench on the knurled surface of the outer circumference of the locking ring 302; as the locking ring 302 is tightened, the locking ring 302 gradually moves inward along the outer taper surface of the close-in sleeve 301. In this process, the close-in sleeve 301 is extruded by the locking ring 302 to produce radial shrinkage.

[0032] Since the wall of the close-in sleeve 301 gradually decreases in diameter from the side close to the joint pipe 200 to the distal end, the shrinkage force can uniformly act on the end of the oil casing body 100, thereby further clamping the oil casing body 100. The anti-skid pad 303 fixedly installed or bonded on the inner wall of the close-in sleeve 301 increases the friction between the two during the clamping of the close-in sleeve 301 on the oil casing body 100, effectively preventing relative sliding between the oil casing body 100 and the close-in sleeve 301.

[0033] Specifically, through the above working process, the clamping force of the close-in sleeve 301 on the end of the oil casing body 100 is greatly increased, making the connection between the oil casing body 100 and the joint pipe 200 more tight and stable, reducing the axial relative sliding caused by vibration or alternating load during oil production, effectively avoiding the occurrence of the wire slipping phenomenon, ensuring the stability of the oil casing connection part, thereby enhancing the sealing performance. Effectively prevent the leakage problem caused by the gap at the threaded sealing part, ensure the normal operation of oil production. The rest of the structure is the same as that of example 1.

[0034] Example 3, refer to Figures 1-7 This is the third embodiment of the present application, which is different from the first embodiment: the load sharing member 400 includes a sliding ring 401 slidingly installed on the outside of the joint pipe 200, and the inner diameter of the sliding ring 401 is smaller than the outer diameter of the locking ring 302, and the outer wall of the joint pipe 200 is provided with a sliding groove 402 for the axial movement of the sliding ring 401, and a plurality of insertion rods 403 are movably and penetratingly arranged on the wall of the joint pipe 200, and the wall of the joint pipe 200 is provided with perforations 404 matched with the insertion rods 403.

[0035] Refer to Figure 3 and Figure 5The opposite end faces of the two oil jacket pipe bodies 100 are provided with sealing grooves 110, the two sealing grooves 110 are staggered, each sealing groove 110 is provided with a hollow sealing ring 500, the number of the insertion rods 403 is not less than two, one end of the insertion rod 403 is provided with a wedge block 405, and the wedge block 405 is located outside the joint pipe fitting 200; when the sliding ring 401 moves to the middle part of the joint pipe fitting 200, the wall body of the sliding ring 401 extrudes the inclined surface of the wedge block 405, and the wedge block 405 drives the insertion rod 403 to move to the inside of the joint pipe fitting 200.

[0036] Specifically, the hollow sealing ring 500 is made of high-temperature-resistant material, the opposite end faces of the two oil jacket pipe bodies 100 are sealing surfaces, during the screwing of the locking ring 302, the locking ring 302 continuously approaches the middle part of the joint pipe fitting 200, and simultaneously moves the sliding ring 401 in the sliding groove 402 to move axially. When the sliding ring 401 moves to the middle part of the joint pipe fitting 200, the wall body of the sliding ring 401 extrudes the inclined surface of the wedge block 405, the wedge block 405 is connected with the insertion rod 403, after being extruded by the sliding ring 401, the wedge block 405 drives the insertion rod 403 to move to the inside of the joint pipe fitting 200, and is inserted into the perforation 404 on the joint pipe fitting 200, thereby forming an effective auxiliary support structure between the outer peripheral wall of the oil jacket pipe body 100 and the inner wall of the joint pipe fitting 200.

[0037] Referring to Figure 5 With Figure 8 A limiting ring 406 is sleeved on the insertion rod 403, a first spring 407 is sleeved on the insertion rod 403, two ends of the first spring 407 are respectively abutted against the opposite faces of the joint pipe fitting 200 and the limiting ring 406, a piston 4011 is slidably connected in the perforation 404, one end of a sliding rod 4010 connected with the piston 4011 is sleeved on the piston 4011, the other end of the sliding rod 4010 is slidably connected in the insertion rod 403, a second spring 4012 is sleeved on the sliding rod 4010, two ends of the second spring 4012 are respectively abutted against the opposite faces of the insertion rod 403 and the piston 4011, a gas cavity is formed between the upper surface of the piston 4011 and the lower surface of the insertion rod 403, a gas channel is arranged in the oil jacket pipe body 100, one end of the gas channel is communicated with the gas cavity, and the other end of the gas channel is communicated with the corresponding hollow sealing ring 500.

[0038] Specifically, the first spring 407 is arranged to facilitate the disassembly of the port card connector 300 or adjustment of the oil casing body 100. When the first spring 407 exerts an outward force on the limiting ring 406, the plunger 403 is moved outward to reset, so that the plunger 403 is separated from the outer peripheral wall of the oil casing body 100, facilitating subsequent operation. When the sliding ring 401 does not press the wedge block 405 and the plunger 403, the plunger 403 is located in the inner side wall of the joint pipe 200 under the elastic support of the first spring 407, so as not to extend into the inner cavity of the joint pipe 200, avoiding affecting the threaded installation of the oil casing body 100 in the inner cavity of the joint pipe 200. The bottom end of the plunger 403 is provided with a sealing rubber ring to ensure the air tightness of the air cavity formed between the plunger 403 and the piston 4011.

[0039] In the optional embodiment, the two oil casing bodies 100 are inserted into the two end closing sleeves 301 respectively, and the opposite end faces of the two oil casing bodies 100 abut against each other, and then the two hollow sealing rings 500 abut against the corresponding end faces of the corresponding oil casing bodies 100 respectively, so as to form two seals and improve the sealing performance. Figure 8 As shown, by moving the two sliding rings 401 towards the middle of the joint pipe 200, the wedge blocks 405 are forced to move towards the axis of the oil casing body 100. At this time, the limiting ring 406 moves downward, and the first spring 407 is compressed. At this time, the sliding rod 4010 moves downward synchronously with the piston 4011, and the second spring 4012 is in a natural state, that is, the plunger 403 is separated from the oil casing body 100. Figure 8 From the left state to the middle state, it should be noted that the volume of the air cavity does not change from the left state to the middle state, and the air passage is always in communication with the air cavity. After all the components are installed in place, the oil casing body 100 starts to transport oil and gas. When the pressure of the oil and gas transported in the oil casing body 100 becomes larger, due to the strong penetration ability of high-pressure gas molecules, it may cause a small relative displacement or separation of the sealing contact surface, resulting in a decrease in the sealing effect of the hollow sealing ring 500, which is prone to leakage problems. From the middle state to the right state, the oil casing body 100 is separated from the joint pipe 200, and the oil casing body 100 is removed from the joint pipe 200. Figure 8When the oil and gas pressure becomes larger, the oil and gas at the lower part of the perforation 404 exerts a greater pressure on the piston 4011, and the piston 4011 is displaced upward by a greater distance. In this process, the slide rod 4010 slides upward along the inside of the insertion rod 403, and the second spring 4012 is compressed, so that more gas in the air cavity enters the gas passage, and more gas enters the inside of the hollow sealing ring 500, so that the hollow sealing ring 500 is stretched to be more swollen and harder, the contact pressure of the hollow sealing ring 500 on the sealing surface is increased, the leakage of oil and gas from the sealing surface is avoided, and the temperature of the high-pressure oil and gas is also higher. The higher the temperature, the softer the hollow sealing ring 500, the lower the elasticity, and the lower the sealing performance. By inflating the hollow sealing ring 500, the hollow sealing ring 500 is stretched to be hard, so that the sealing performance is improved, and the sealing performance of the hollow sealing ring 500 is adaptively improved according to the oil and gas pressure in the oil casing main body 100. Not only is the high-pressure leakage risk eliminated, but also the traditional sealing thermal relaxation leakage problem is solved.

[0040] With reference to Figure 6 and Figure 7 The two slide rings 401 are welded or fixedly installed with locking plates 408 on the side close to each other, the locking plate 408 comprises an insertion strip 4081 connected with the outer wall of the slide ring 401, the insertion strip 4081 is made of elastic material, and the end of the insertion strip 4081 is integrally provided with a clamping block 4082; the number of the locking plates 408 is not less than two, and the wall body of the joint pipe fitting 200 is provided with an L-shaped groove 409 for inserting the locking plate 408.

[0041] Specifically, as the slide ring 401 continuously moves, the insertion strip 4081 of the locking plate 408 is made of elastic material, and the locking plate 408 is inserted into the L-shaped groove 409 on the wall body of the joint pipe fitting 200. During the insertion process, the clamping block 4082 is extruded by the groove wall of the L-shaped groove 409, so that the insertion strip 4081 is elastically deformed. When the clamping block 4082 passes the corner of the L-shaped groove 409, the insertion strip 4081 restores elasticity, and the clamping block 4082 is clamped into the transverse groove of the L-shaped groove 409, so as to fix the locking plate 408 in the L-shaped groove 409, and further limit the axial movement of the slide ring 401, so that the insertion rod 403 always maintains the state of abutting against the peripheral wall of the oil casing main body 100. When disassembling, force needs to be applied in the opposite direction to deform the insertion strip 4081 again, so that the clamping block 4082 is removed from the transverse groove of the L-shaped groove 409, so that the locking of the slide ring 401 is released. The remaining structure is the same as that of the second embodiment.

[0042] With reference to Figure 7 This is the fourth embodiment of the present application, which is different from the second embodiment in that the clamping block 4082 is in a trapezoidal protruding structure with an inclined surface, and the inclination angle a of the inclined surface of the clamping block 4082 is greater than 90 degrees.

[0043] Specifically, this special trapezoidal protruding structure makes the inclined surface of the locking piece 408 better fit the wall of the L-shaped slot 409 after being inserted into the L-shaped slot 409. The contact between the clamping block 4082 and the slot wall is more closely when the inclination angle is greater than 90 degrees, so that the clamping block 4082 and the L-shaped slot 409 do not have a gap, so that the sliding ring 401 has a loose sign. At the same time, the larger inclination angle makes the clamping block 4082 produce a certain extrusion deformation on the slot wall during the insertion process, further filling the possible small gap, enhancing the sealing and stability of the overall structure.

[0044] Specifically, when the clamping block 4082 is inserted into the L-shaped slot 409, the inclined surface greater than 90 degrees makes the clamping block 4082 generate greater friction and engagement force between the inclined surface and the L-shaped slot 409 slot wall when subjected to axial tension along the L-shaped slot 409 slot wall. Because the inclination angle is large, the component of the tension in the direction perpendicular to the inclined surface is larger, thereby increasing the pressure between the clamping block 4082 and the slot wall. The increase in pressure increases the friction, effectively preventing the clamping block 4082 from being loosened from the L-shaped slot 409, thereby ensuring the locking effect of the locking piece 408 on the sliding ring 401 and ensuring the stable operation of the load sharing member 400. The rest of the structure is the same as that of Example 3.

[0045] In summary, the working principle of the present application is as follows: In view of the problem of thread slip and wear leakage of the existing oil casing caused by dynamic load during oil production, the present application solves the sealing failure problem of the oil casing body 100 under dynamic load through the cooperation of the port clamping member 300 and the load sharing member 400. The port clamping member 300 exerts a radial clamping force on the end of the oil casing to suppress the axial sliding of the thread contact surface. During the installation of the port clamping member 300, the load sharing member 400 is driven to work to drive the insertion rod 403 to abut against the outer peripheral wall of the oil casing body 100 to form an auxiliary support structure, thereby bearing the radial shear force and reducing the leakage phenomenon of the gap between the oil casing body 100 and the threaded sealing part of the joint pipe 200.

[0046] The above examples are only used to illustrate the technical solutions of the present application, but not to limit it; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part of the technical features; and these modifications or replacements will not make the essence of the corresponding technical solutions deviate from the protection scope of the technical solutions of the embodiments of the present application.

Claims

1. An oil casing gas seal buckle structure, comprising two oil casing bodies (100) and a joint pipe (200), the connecting end of each of the two oil casing bodies (100) is provided with an external thread, and the inner side of the two ends of the joint pipe (200) is provided with an internal thread matched with the external thread, and when the opposite end faces of the two oil casing bodies (100) abut against each other, the joint pipe (200) is used to be sleeved on the two oil casing bodies (100), characterized in that, Also include: The port card connector (300) is detachably arranged at both ends of the joint pipe (200), and the port card connector (300) is used for further fastening the end of the oil casing body (100); The load sharing member (400) is arranged inside the port card connector (300), and the load sharing member (400) is used for reducing the stress concentration of the thread on the oil casing body (100) and the joint pipe (200); Wherein, during the overall installation of the port card connector (300) on the joint pipe (200), the driving load sharing member (400) moves along the radial direction of the oil casing body (100) and abuts against the outer peripheral wall of the oil casing body (100), so as to form an auxiliary support structure between the outer peripheral wall of the oil casing body (100) and the inner wall of the joint pipe (200).

2. The oil casing gas seal retainer structure of claim 1, wherein, The port card connector (300) includes a closed sleeve (301) arranged at the end of the joint pipe (200), the wall of the closed sleeve (301) gradually reduces from the side close to the joint pipe (200) to the distal end diameter, and the minimum inner diameter of the closed sleeve (301) is equal to the diameter of the oil casing body (100); The outer side of the closed sleeve (301) is threadedly connected with a locking ring (302), and the inner diameter of the locking ring (302) is consistent with the matching size of the outer taper surface of the closed sleeve (301), the closed sleeve (301) is radially contracted by the contact of the outer taper surface when the locking ring (302) is screwed, and the inner side wall of the closed sleeve (301) is provided with an anti-skid pad (303).

3. The oil casing gas seal retainer structure of claim 2, wherein, The opposite end faces of the two oil casing bodies (100) are each provided with a sealing groove (110), and the two sealing grooves (110) are arranged staggered with each other, and each of the sealing grooves (110) is provided with a hollow sealing ring (500).

4. The oil casing gas seal retainer structure of claim 2, wherein, The outer circumferential surface of the locking ring (302) is provided with knurling.

5. The oil casing gas seal retainer structure of claim 3, wherein, The load sharing member (400) includes a sliding ring (401) arranged outside the joint pipe (200), and the inner diameter of the sliding ring (401) is smaller than the outer diameter of the locking ring (302), the outer wall of the joint pipe (200) is provided with a sliding groove (402) for the axial movement of the sliding ring (401), and a plurality of insertion rods (403) are movably and penetratively arranged on the wall of the joint pipe (200), and the wall of the joint pipe (200) is provided with a perforation (404) matched with the insertion rod (403).

6. The oil casing gas seal retainer structure of claim 5, wherein, The number of the insertion rods (403) is not less than two, one end of the insertion rod (403) is provided with a wedge block (405), and the wedge block (405) is located outside the joint pipe (200); When the sliding ring (401) moves to the middle part of the joint pipe (200), the wall of the sliding ring (401) extrudes the inclined surface of the wedge block (405), and the wedge block (405) drives the insertion rod (403) to move to the inner side of the joint pipe (200).

7. The oil casing gas seal retainer structure of claim 6, wherein, The plug rod (403) is sleeved with a limiting ring (406), the plug rod (403) is sleeved with a first spring (407), the two ends of the first spring (407) are respectively abutted on the opposite surfaces of the joint pipe (200) and the limiting ring (406), the piston (4011) is slidably connected in the through hole (404), one end of the slide rod (4010) connected with the piston (4011) is slidably connected in the plug rod (403), the second spring (4012) is sleeved on the slide rod (4010), the two ends of the second spring (4012) are respectively abutted on the opposite surfaces of the plug rod (403) and the piston (4011), the air cavity is formed between the upper surface of the piston (4011) and the lower surface of the plug rod (403), the air channel is arranged in the oil jacket pipe body (100), one end of the air channel is communicated with the air cavity, the other end of the air channel is communicated with the corresponding hollow sealing ring (500).

8. The oil casing gas seal retainer structure of claim 6, wherein, The two slide rings (401) are provided with lock plates (408) on the sides close to each other, the lock plate (408) comprises an insertion strip (4081) connected with the outer wall of the slide ring (401), and the insertion strip (4081) is made of elastic material, and the end portion of the insertion strip (4081) is integrally provided with a clamping block (4082).

9. The oil casing gas seal retainer structure of claim 8, wherein, The clamping block (4082) is a trapezoidal convex structure with an inclined surface, and the inclination angle α of the inclined surface of the clamping block (4082) is greater than 90 degrees.

10. The oil casing gas seal retainer structure of claim 8 or 9, wherein, The number of the lock plates (408) is not less than two, and the wall body of the joint pipe (200) is provided with an L-shaped slot (409) for inserting the lock plate (408).

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