An oil pipe thread connection gas-tight coupling

Abstract

The present invention discloses a gas-tight connection buckle for oil pipe threads, specifically relating to the technical field of oil pipe thread connections. It includes a connection buckle and an oil casing. The connection buckle is a cylindrical structure with openings at both ends. The oil casing is threadedly connected to the end of the connection buckle. Two symmetrically distributed gas grooves and a first sealing groove are formed inside the connection buckle, and second sealing grooves are respectively formed at both ends of the connection buckle. A dynamic sealing assembly is arranged inside the connection buckle, and a second sealing member is arranged inside each second sealing groove. A plurality of uniformly distributed air inlet pipes are formed on the inner wall of the connection buckle, and the second sealing member is communicated with the gas groove through the air inlet pipe. In the present invention, the first sealing member slides inside the adjusting member and the second sealing member seals the bottom of the connection buckle, preventing leakage caused by gaps due to loosening of the connection when the oil pipe vibrates under the impact of dynamic loads.

Description

Technical Field

[0001] The present invention relates to the technical field of oil pipe thread connections. More specifically, the present invention relates to a gas-tight connection for oil pipe threads. Background Art

[0002] A threaded joint refers to a pipe fitting with threads and is one of the most common pipe fittings in industry and daily life. Threaded joints make pipe connections simpler and easier to disassemble and replace, greatly saving the cost of pipe connections. The oil casing in a high-pressure gas well is also connected through threaded joints. Existing oil pipe thread connections improve the sealing performance between the threaded joint and the oil casing by improving the thread profile.

[0003] However, in the prior art, during the process of oil and gas exploitation, when the oil casing is placed into the oil well, the oil casing will shake, and during oil production, the casing will also be subjected to various dynamic loads, such as vibration and impact. Under long-term working conditions, the threaded connection is prone to looseness, resulting in gaps in the sealing part and leakage. Therefore, the present invention proposes a gas-tight connection for oil pipe threads to solve the above problems. Summary of the Invention

[0004] In order to overcome the above-mentioned defects of the prior art, an embodiment of the present invention provides a gas-tight connection for oil pipe threads, which solves the problems raised in the above background art by setting a dynamic sealing component and a static sealing component.

[0005] To achieve the above object, the present invention provides the following technical solution: A gas-tight connection for oil pipe threads, including a connection buckle with a cylindrical structure at both ends and an oil casing threadedly connected to the end of the connection buckle, further including:

[0006] Gas grooves, which are opened inside the connection buckle, and two gas grooves are symmetrically distributed;

[0007] First sealing grooves, which are opened inside the connection buckle, and two first sealing grooves are symmetrically distributed;

[0008] Second sealing grooves, there are two of them, which are respectively opened at both ends of the connection buckle and are located inside the connection buckle;

[0009] A dynamic sealing component, which includes:

[0010] An adjusting member, which is slidably arranged in the gas groove;

[0011] A first sealing member, which is slidably arranged in the first sealing groove;

[0012] One end of the adjusting member extends into the corresponding first sealing groove and is connected to the corresponding first sealing member;

[0013] One end of the first seal away from the adjusting member contacts the end of the oil casing.

[0014] Second seals, which are arranged in the second seal grooves. There are two second seals, corresponding to the two second seal grooves respectively.

[0015] The intake pipes are opened inside the connection buckle and are provided with a plurality of them, which are evenly distributed. The intake pipes are used to connect the second seals and the air grooves.

[0016] When the adjusting member slides inside the air groove, the second seal can be deformed.

[0017] Preferably, the adjusting member includes a piston ring slidably connected to the inner wall of the air groove. One end of the piston ring is fixedly connected with a plurality of piston rods. A first elastic member is sleeved on the outer wall of each piston rod. One end of the first elastic member is fixedly connected with the end of the piston ring close to the piston rod, and the other end of the first elastic member is fixedly connected with the inner wall of the air groove close to one end of the first seal groove.

[0018] Preferably, one end of each piston rod away from the piston ring extends into the first seal groove. One ends of each piston rod extending into the first seal groove are fixedly connected together with a slider. A chute is opened in the slider. A second elastic member is arranged inside the chute. One end of the second elastic member is fixedly connected with the top end of the chute, and the other end of the second elastic member is fixedly connected with the end of the first seal away from the oil casing.

[0019] Preferably, threads are symmetrically arranged at both ends of the connection buckle along the middle section. The threads at each end are divided into two sections, and static seal assemblies are arranged between the two internal threads.

[0020] Preferably, the static seal assembly includes a third seal and a fourth seal. The third seal is fixedly connected with the inner wall of the connection buckle. The fourth seal is movably connected with the third seal, and the fourth seal contacts the inner wall of the oil casing.

[0021] Preferably, stepped grooves are opened inside both the third seal and the fourth seal, and the stepped grooves of the third seal and the fourth seal are alternately embedded with each other.

[0022] Preferably, a plurality of exhaust ports are opened on the outer wall of the air groove, and the exhaust ports respectively correspond to the intake pipes. A plurality of intake ports are opened on the second seal, and the intake ports respectively correspond to the intake pipes.

[0023] Preferably, a plurality of exhaust pipes are opened inside the connection buckle, and the exhaust pipes are respectively communicated with the intake pipes.

[0024] Preferably, a limiting groove is formed inside the connecting buckle, a baffle is slidably connected inside the limiting groove, and a through hole corresponding to the exhaust hole is formed on the baffle.

[0025] Preferably, when the baffle slides to the extreme position inside the connecting buckle, the through hole communicates with the exhaust hole, and when the baffle slides to the extreme position outside the connecting buckle, the exhaust hole is sealed.

[0026] Technical effects and advantages of the present invention:

[0027] 1. In the present invention, the first seal slides inside the adjusting member to prevent leakage caused by gaps due to loose connections when the oil pipe vibrates in the axial direction.

[0028] 2. In the present invention, static seals cooperate with each other to form multiple-stage tracks, reducing the flow rate and pressure during leakage, enhancing the sealing effect. At the same time, the bottom of the connecting buckle is sealed by the second seal to prevent leakage caused by vibration of the oil pipe in the radial direction.

[0029] 3. In the present invention, by providing an exhaust pipe and a baffle, after the oil casing completely enters the connecting buckle, the second seal seals, and when the oil casing disengages, the second seal discharges gas, reducing the friction between the oil casing and the seal and increasing the service life of the seal. Description of the drawings

[0030] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0031] Figure 2 It is a cross-sectional view of the overall structure of the connecting buckle of the present invention.

[0032] Figure 3 It is a cross-sectional view when the oil casing is connected to the connecting buckle of the present invention.

[0033] Figure 4 For the present invention Figure 3 Enlarged view of the structure of part A.

[0034] Figure 5 It is a cross-sectional view when the oil casing is not connected to the connection port of the present invention.

[0035] Figure 6 For the present invention Figure 5 Enlarged view of the structure of part B.

[0036] Figure 7 It is a cross-sectional view of the overall structure of the adjusting member of the present invention.

[0037] Figure 8 For the present invention Figure 3 Enlarged view of the structure of part C.

[0038] Figure 9This is a cross-sectional view of the overall structure of the third and fourth seals of the present invention.

[0039] The reference numerals are: 1, connecting buckle; 11, air groove; 12, first sealing groove; 13, second sealing groove; 14, intake pipe; 15, exhaust pipe; 16, limiting groove; 17, baffle; 171, through hole; 2, dynamic sealing assembly; 21, adjusting member; 211, piston ring; 212, piston rod; 213, slider; 214, sliding groove; 22, first seal; 23, second seal; 231, air inlet; 24, first elastic member; 25, second elastic member; 3, oil casing pipe; 4, static sealing assembly; 41, third seal; 42, fourth seal. Detailed implementation manners

[0040] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention. Embodiment 1

[0041] During the actual use process, since the casing pipe will also be affected by various dynamic loads during oil production, such as vibration, impact, etc., the threaded connection is likely to become loose under long-term working conditions, resulting in gaps at the sealing parts and leakage. To solve the above problems, this embodiment is specifically invented.

[0042] Please refer to Figure 1 and Figure 2 As shown, a gas-tight connection buckle for an oil pipe thread connection according to an embodiment of the present invention includes a connecting buckle 1 and an oil casing pipe 3. The connecting buckle 1 is a cylindrical structure with openings at both ends. The oil casing pipe 3 is threadedly connected to the end of the connecting buckle 1. Two symmetrically distributed air grooves 11 and a first sealing groove 12 are provided inside the connecting buckle 1, and second sealing grooves 13 are provided at both ends of the connecting buckle 1 respectively; please combine Figure 5 and Figure 6 As shown, a dynamic sealing assembly 2 is arranged inside the connecting buckle 1. The dynamic sealing assembly 2 includes an adjusting member 21 that is slidably connected inside the corresponding air groove 11 respectively. One end of the adjusting member 21 extends into the first sealing groove 12, and a first seal 22 is arranged at the end of the adjusting member 21 that extends into the corresponding first sealing groove 12. Please combine Figure 3 and Figure 4As shown, one end of the first seal 22 away from the adjusting member 21 contacts the end of the oil casing 3; a second seal 23 is provided inside each second seal groove 13, and a plurality of uniformly distributed air inlet pipes 14 are formed inside the connecting buckle 1. The second seal 23 is communicated with the air groove 11 through the air inlet pipes 14; when the adjusting member 21 slides inside the air groove 11, the second seal 23 can be deformed. Among them, both the first seal 22 and the second seal 23 are made of elastic materials.

[0043] Please refer to Figure 4 As shown, the adjusting member 21 includes a piston ring 211 slidably connected to the inner wall of the air groove 11. One end of the piston ring 211 is fixedly connected with a plurality of piston rods 212. A first elastic member 24 is sleeved on the outer wall of each piston rod 212. One end of the first elastic member 24 is fixedly connected to the end of the piston ring 211 close to the piston rod 212, and the other end of the first elastic member 24 is fixedly connected to the inner wall of the air groove 11 close to one end of the first seal groove 12. Among them, the first elastic member 24 is a spring.

[0044] Please refer to Figure 6 and Figure 7 As shown, one end of each piston rod 212 away from the piston ring 211 extends into the first seal groove 12. One end of each piston rod 212 extending into the first seal groove 12 is fixedly connected together with a slider 213. A chute 214 is formed inside the slider 213. A second elastic member 25 is provided inside the chute 214. One end of the second elastic member 25 is fixedly connected to the top end of the chute 214, and the other end of the second elastic member 25 is fixedly connected to one end of the first seal 22 away from the oil casing 3. Among them, the second elastic member 25 is a spring, and the slider 213 is in clearance fit with the first seal groove 12.

[0045] During use, first insert the threaded end of the tubing-casing 3 into the inside of the connection buckle 1, and gradually fix the tubing-casing 3 to the connection buckle 1 through thread engagement. During the installation of the tubing-casing 3, when the end of the tubing-casing 3 comes into contact with the first seal 22, at this time, by continuing to move the tubing-casing 3 into the connection buckle 1, the first seal 22 slides inside the first seal groove 12, and at the same time, the first seal 22 slides inside the chute 214 in the direction close to the piston rod 212, so that the second elastic member 25 is compressed. As the second elastic member 25 is gradually compressed, the pressure on the slider 213 gradually increases. When the pressure on the slider 213 is greater than the elastic force of the first elastic member 24, the second elastic member 25 drives the slider 213 to slide inside the first seal groove 12. The slider 213 pushes the piston rod 212 to drive the piston ring 211 to slide inside the air groove 11, causing the first elastic member 24 to expand. The gas inside the air groove 11 enters the second seal 23 through the air inlet pipe 14, and the second seal 23 gradually expands. When the tubing-casing 3 vibrates axially and causes the threaded connection to loosen, the second elastic member 25 expands so that the first seal 22 and the tubing-casing 3 are always in a sealed state, preventing the tubing-casing 3 from vibrating axially due to the action of dynamic loads during oil production, resulting in the loosening of the threaded connection and causing oil and gas leakage. Embodiment 2

[0046] It is found in actual use that when the tubing-casing 3 vibrates in the radial direction due to the action of dynamic loads, the sealing effect of the first seal 22 is not good, resulting in leakage. Further improvements are made on the basis of the above embodiments.

[0047] Please refer to Figure 3 and Figure 5 As shown, threads are symmetrically arranged at both ends of the connection buckle 1 along the middle section. The threads at each end are divided into two sections, and a static seal assembly 4 is arranged between the two sections of internal threads. Combining Figure 8 and Figure 9 As shown, the static seal assembly 4 includes a third seal 41 and a fourth seal 42. The third seal 41 is fixedly connected to the inner wall of the connection buckle 1, the fourth seal 42 is movably connected to the third seal 41, the fourth seal 42 is in contact with the inner wall of the tubing-casing 3, stepped grooves are formed inside both the third seal 41 and the fourth seal 42, and the stepped grooves of the third seal 41 and the fourth seal 42 are alternately nested with each other. Among them, both the third seal 41 and the fourth seal 42 are made of elastic materials.

[0048] Based on the above embodiments, during use, when the oil casing 3 is completely installed inside the connection buckle 1, the third seal 41 and the fourth seal 42 are squeezed at this time. When the oil casing 3 undergoes radial vibration and causes oil and gas to leak to the static seal assembly 4, due to the radial vibration, a small gap is generated between the third seal 41 and the fourth seal 42, so that the leaked oil and gas enter the space between the third seal 41 and the fourth seal 42. Through the stepped grooves inside the third seal 41 and the fourth seal 42 being nested with each other, a multi-layer seal maze is formed, changing the flow direction of the leaked oil and gas and buffering the pressure at the oil and gas leakage point. At the same time, because the slight offset of the radial vibration of the oil casing 3 can squeeze the gas inside the second seal 23, the gas inside the second seal 23 moves from the squeezed side to the unsqueezed side, thus ensuring that the second seal 23 is always in a sealed state with the oil casing 3, preventing the situation of oil and gas leakage due to insufficient sealing performance of the first seal 22 when the oil casing 3 generates radial vibration due to dynamic load. Embodiment 3

[0049] It is found in actual use that during the installation and disassembly of the oil casing 3, since the outer wall of the thread will rub the seal during the disassembly process, the service life of the seal is reduced, increasing the risk of oil and gas leakage. Further improvements are made based on the above embodiments.

[0050] Please refer to Figure 3 As shown, a plurality of exhaust ports are provided on the outer wall of the gas groove 11, and the exhaust ports correspond to the intake pipes 14 respectively. A plurality of intake ports 231 are provided on the second seal 23, and the intake ports 231 correspond to the intake pipes 14 respectively. Please combine Figure 4 As shown, a plurality of exhaust pipes 15 are provided inside the connection buckle 1, and the exhaust pipes 15 are respectively communicated with the intake pipes 14. The first seal 22 can seal the exhaust pipes 15 by sliding.

[0051] Please refer to Figure 4 As shown, a limiting groove 16 is provided inside the connection buckle 1, and a baffle 17 is slidably connected inside the limiting groove 16. A through hole 171 corresponding to the exhaust hole is provided on the baffle 17. Please combine Figure 6 As shown, when the baffle 17 slides to the extreme position inside the connection buckle 1, the through hole 171 is communicated with the exhaust hole, and when the baffle 17 slides to the extreme position outside the connection buckle 1, the exhaust hole is sealed.

[0052] Based on the above embodiments, during use, when the piston ring 211 slides inside the gas groove 11, the gas inside the gas groove 11 is compressed at this time. When the piston ring 211 moves to contact the baffle 17, the inside of the piston ring 211 pushes the baffle 17 to move inside the connecting buckle 1, so that the gas inside the limiting groove 16 is compressed. When the piston ring 211 moves to the extreme position, the oil casing 3 is completely installed inside the connecting buckle 1 at this time. At this time, the exhaust pipe 15 is sealed by the first seal 22. At the same time, the through hole 171 communicates with the exhaust hole of the gas groove 11, and the gas enters the inside of the second seal 23 through the intake pipe 14, so that the second seal 23 expands and fits tightly with the oil casing 3 for sealing. During the process of removing the oil casing 3 after oil production is completed, as the oil casing 3 is gradually removed, the second elastic member 25 gradually expands, causing the first seal 22 to slide outside the connecting buckle 1. By the movement of the first seal 22, the exhaust pipe 15 is no longer sealed, so that the gas inside the second seal 23 is quickly discharged, causing the second seal 23 to contract. By supplying gas to the second seal 23 after the oil casing 3 completely enters the connecting buckle 1 and discharging the gas of the second seal 23 when the oil casing 3 is detached, the friction between the oil casing 3 and the seal is reduced, and the service life of the seal is increased.

[0053] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A gas-tight seal for oil pipe threaded connection, comprising a connecting buckle with cylindrical structures at both ends and an oil casing threadedly connected to the ends of the connecting buckle, characterized in that: Also includes: The air grooves are arranged inside the connecting buckle and are symmetrically distributed with two of them; The first sealing groove is provided inside the connecting buckle and two of them are symmetrically arranged; There are two second sealing grooves, which are respectively opened on the inner side and both ends of the connecting buckle; Dynamic seal assembly, including: An adjusting member, which is slidably disposed in the air groove; A first sealing member slidably disposed in the first sealing groove; One end of the adjusting member extends into the corresponding first sealing groove and is connected to the corresponding first sealing member; An end of the first sealing member away from the adjusting member contacts the end of the oil casing; There are two second sealing members, which are arranged in the second sealing grooves and correspond to the two second sealing grooves respectively; An air inlet pipe is opened inside the connecting buckle, and a plurality of the air inlet pipes are provided and evenly distributed, and the air inlet pipes are used to connect the second sealing member and the air groove; The adjusting member can cause the second sealing member to deform when sliding inside the air groove; the adjusting member includes a piston ring slidably connected to the inner wall of the air groove, one end of the piston ring is fixedly connected to a plurality of piston rods, the outer wall of each piston rod is sleeved with a first elastic member, one end of each first elastic member is fixedly connected to an end of the piston ring close to the piston rod, and the other end of each first elastic member is fixedly connected to the inner wall of one end of the air groove close to the first sealing groove; There are threads at both ends of the connecting buckle, and the threads at each end are divided into two sections, and a static sealing component is provided between the two sections of internal threads; The static seal assembly includes a third seal fixedly connected to the inner wall of the connecting buckle and a fourth seal in contact with the inner wall of the oil casing. The third seal and the fourth seal are both provided with stepped grooves inside, and the stepped grooves are alternately embedded in each other. A limit groove is provided inside the connecting buckle, a baffle is slidably connected inside the limit groove, and a through hole corresponding to the exhaust hole is provided on the baffle; When the piston ring moves to the extreme position, the exhaust pipe is sealed by the first seal, the through hole is connected with the exhaust hole of the gas groove, and the gas enters the second seal through the intake pipe, so that the second seal expands and seals with the oil casing; when the oil casing is taken out after the oil production is completed, the exhaust pipe is no longer sealed by the movement of the first seal, so that the gas inside the second seal is quickly discharged, so that the second seal contracts, and the second seal is supplied with gas after the oil casing completely enters the connecting buckle, and the gas of the second seal is discharged when the oil casing is detached; When the oil casing vibrates radially and causes oil and gas to leak to the static seal assembly, the radial vibration of the oil casing causes a slight deviation, which can squeeze the gas inside the second seal, causing the gas inside the second seal to move and flow from the squeezed side to the non-squeezed side, thereby ensuring that the second seal is always in a sealed state with the oil casing.

2. The gas-tight seal for oil pipe threaded connection according to claim 1, characterized in that: One end of each piston rod (212) away from the piston ring (211) extends into the first sealing groove (12), and one end of each piston rod (212) extending into the first sealing groove (12) is fixedly connected to a slider (213), a slide groove (214) is provided in the slider (213), a second elastic member (25) is provided inside the slide groove (214), one end of the second elastic member (25) is fixedly connected to the top end of the slide groove (214), and the other end of the second elastic member (25) is fixedly connected to one end of the first sealing member (22) away from the oil casing (3).

3. The gas-tight seal for oil pipe threaded connection according to claim 2, characterized in that: The outer wall of the air groove (11) is provided with a plurality of exhaust ports, each of which corresponds to the air intake pipe (14); the second sealing member (23) is provided with a plurality of air intake ports (231), each of which corresponds to the air intake pipe (14).

4. The hermetic seal for oil pipe threaded connection according to claim 1, characterized in that: A plurality of exhaust pipes (15) are provided inside the connecting buckle (1), and the exhaust pipes (15) are respectively connected to the air inlet pipes (14).

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