Old oil pipe pressure test sealing system

Abstract

An old oil pipe pressure test sealing system belongs to the technical field of oil pipe pressure test, and comprises two groups of plugging assemblies, each plugging assembly comprises a cover plate and a push rod; a guide cylinder is coaxially arranged on one side of the cover plate, a baffle is arranged at the tail end of the guide cylinder, a plurality of strip-shaped holes are formed in the side wall of the guide cylinder along the circumference, the guide cylinder is sleeved with a pressing ring and a sealing ring, and the sealing ring is located between the pressing ring and the baffle; the front end of the push rod coaxially penetrates through the cover plate and the baffle, a connecting rod penetrating through the strip-shaped hole is arranged at the front end of the push rod towards the outer side, the outer end of the connecting rod is connected to the pressing ring, a liquid injection hole is formed in the push rod in the axis direction and used for injecting liquid into the oil pipe, and the liquid injection hole is connected with an external pressurization detection instrument. The ends, provided with the baffles, of the two plugging assemblies are oppositely and coaxially arranged, and the plugging assemblies are further provided with driving elements for driving the push rods. According to the scheme, the oil pipe can be quickly blocked and unblocked, sealing of the circumferential sealing end face can be achieved at the same time, and better sealing performance is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of oil pipe pressure testing, and in particular relates to a pressure testing sealing system for an old oil pipe. Background Art

[0002] Pressure testing is an important means of inspecting the quality of various oil pipelines. To reduce production costs, used oil pipelines in oil fields can be reused after repair. However, to ensure the quality of the repaired oil pipelines, pressure testing is usually required.

[0003] In the existing pressure testing process, in order to maintain the pressure inside the oil pipe, threaded plugs are usually connected to the two ends of the oil pipe. Since the two ends of the oil pipe are internally threaded and externally threaded respectively, not only do plugs with different structures need to be prepared, but the process of disassembling and assembling the plugs in this way is also time-consuming and labor-intensive. On the other hand, this sealing method usually uses gaskets to form end face seals, the sealing structure is relatively simple, and the sealing effect is average. Summary of the Invention

[0004] In order to solve the deficiencies of the existing technology, the present invention provides a used oil pipe pressure test sealing system, which can quickly seal and unseal the oil pipe, and can simultaneously achieve circumferential sealing and end face sealing, with better sealing performance.

[0005] In order to achieve the purpose of the present invention, the following scheme is proposed: A pressure test sealing system for an old oil pipe comprises: two sets of sealing components, each of which comprises a cover plate and a push rod; The outer diameter of the cover plate is larger than the outer diameter of the oil pipe. A guide cylinder is coaxially provided on one side of the cover plate. A baffle with a larger diameter is coaxially provided at the end of the guide cylinder. A plurality of strip-shaped holes are opened along the circumference of the side wall of the guide cylinder, and the length direction of the strip-shaped holes is parallel to the axial direction of the guide cylinder. A pressure ring and a sealing ring are sleeved on the outside of the guide cylinder. The sealing ring is located between the pressure ring and the baffle. The outer diameters of the pressure ring and the baffle are both smaller than the inner diameter of the oil pipe. Before the sealing ring is compressed, its outer diameter is less than or equal to the inner diameter of the oil pipe. The front end of the push rod coaxially passes through the cover plate and the baffle, and a sealing ring is provided between the cover plate, the baffle and the outer wall of the push rod. A connecting rod passing through the strip hole is provided at the front end of the push rod toward the outside. The outer end of the connecting rod is connected to the pressure ring. An injection hole is opened inside the push rod along the axial direction for injecting liquid into the oil pipe. The injection hole is connected to an external pressure detection instrument. The two groups of blocking components are provided with baffles at one end thereof which are arranged opposite to each other and coaxially. The blocking components are also provided with a driving element for directly driving the push rod to move along the axial direction.

[0006] The beneficial effects of the present invention are: 1. This solution only requires moving the push rod along the axis to achieve the sealing and unsealing operations of the oil pipe, which has higher disassembly and assembly efficiency. At the same time, the axial pressure applied to the oil pipe during sealing can effectively fix the oil pipe, avoiding the need for a separate clamping mechanism; 2. When plugging, by pushing the push rod, the cover plate can be pressed against the end face of the oil pipe and the sealing ring can be pressed against the inner wall of the oil pipe at the same time, achieving both end face sealing and circumferential sealing, which helps to improve the sealing effect. In addition, the realization of the two sealing structures only requires driving the push rod, and the implementation method and process are more convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present invention.

[0008] Figure 1 The schematic diagram of the structure of the preferred solution of this application is shown.

[0009] Figure 2 Shown Figure 1 A partial enlarged view of point A in the middle.

[0010] Figure 3 Shows a structural exploded view of the plugging assembly.

[0011] Figure 4 Shows an overall schematic diagram of the plugging assembly.

[0012] Figure 5 A cross-sectional view of this solution is shown when the baffle and the sealing ring are inserted into the end of the oil pipe.

[0013] Figure 6 Shown Figure 5 A partial enlarged view of point B in the middle.

[0014] Figure 7 A cross-sectional view of this solution is shown when the oil pipe is blocked.

[0015] Figure 8 Shown Figure 7 A partial enlarged view of point C in the middle.

[0016] Markings in the figure: cover plate -1, claw -11, protrusion -111, guide cylinder -2, baffle -21, strip hole -22, push rod -3, injection hole -301, connecting rod -31, return spring -32, pressure ring -4, annular groove -41, cylindrical section -42, limit groove -43, sealing ring -5, contraction groove -51, driving element -6, rectangular frame -7, support rod -8, V-shaped support -9, support plate -91, protrusion -911, strip groove -912. DETAILED DESCRIPTION

[0017] To make the objectives, technical solutions and advantages of the embodiments of the present invention more clear, the embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the embodiments described in the present invention are only part of the embodiments of the present invention, rather than all the embodiments.

[0018] like Figure 1 and Figures 3 to 8 As shown, a pressure test sealing system for an old oil pipe includes: two sets of sealing components, and the sealing components include a cover plate 1 and a push rod 3.

[0019] The outer diameter of the cover plate 1 is larger than that of the oil pipe. A guide cylinder 2 is coaxially mounted on one side of the cover plate 1. A baffle 21, with a larger diameter than the guide cylinder 2, is coaxially mounted at the end of the guide cylinder 2. The sidewall of the guide cylinder 2 is circumferentially defined with multiple strip-shaped holes 22, whose lengths are parallel to the axial direction of the guide cylinder 2. A pressure ring 4 and a sealing ring 5 are sleeved around the guide cylinder 2. The sealing ring 5 is positioned between the pressure ring 4 and the baffle 21. The outer diameters of the pressure ring 4 and the baffle 21 are both smaller than the inner diameter of the oil pipe. Before compression, the outer diameter of the sealing ring 5 is less than or equal to the inner diameter of the oil pipe. Optionally, the sealing ring 5 is made of rubber.

[0020] The front end of the push rod 3 coaxially passes through the cover plate 1 and the baffle 21, and a sealing ring is provided between the cover plate 1 and the baffle 21 and the outer wall of the push rod 3. A connecting rod 31 passing through the strip hole 22 is provided at the front end of the push rod 3 toward the outside, and the outer end of the connecting rod 31 is connected to the pressure ring 4. As a preferred solution, a connecting rod 31 is passed through the strip hole 22, and the strip hole 22 and the connecting rod 31 are arranged in a circular array. An injection hole 301 is opened inside the push rod 3 along the axial direction for adding liquid to the oil pipe. The injection hole 301 is connected to an external pressure detection instrument.

[0021] The two groups of blocking assemblies are provided with baffles 21 at one end thereof which are arranged opposite to each other and coaxially. The blocking assemblies are further provided with a driving element 6 for directly driving the push rod 3 to move along the axial direction.

[0022] As a preferred structure, the guide cylinder 2 is connected to the cover plate 1 by screws, and the strip hole 22 passes through one end of the guide cylinder 2 connected to the cover plate 1, so as to facilitate the installation of the connecting rod 31; the baffle 21 can be integrally formed with the guide cylinder 2, or it can be made into a split structure and connected by screws.

[0023] After the oil pipe is in contact with the oil end face, the push rod 3 is pushed forward. Because the cover plate 1 is restricted by the oil pipe end face, the cover plate 1, the guide cylinder 2 and the baffle 21 cannot move further into the oil pipe, while the pressure ring 4 can continue to move into the oil pipe with the push rod 3. During the movement, the pressure ring 4 is used to press the sealing ring 5 against the baffle 21, and the pressure between the baffle 21 and the pressure ring 4 is used to compress the sealing ring 5. Since the inner side of the sealing ring 5 is restricted by the guide cylinder 2, the compressed sealing ring 5 can only expand outward, and then the outer side of the expanded sealing ring 5 is fitted with the inner wall of the oil pipe to form a sealing structure. In this way, the end of the oil pipe can be quickly sealed by moving the push rod 3 toward the oil pipe along the axial direction, which has high installation efficiency. Furthermore, when sealing, the cover plate 1 is used to contact the end face of the oil pipe, which can prevent the sealing ring 5 from tilting in the oil pipe and ensure that the axis of the sealing ring 5 is parallel to the axis of the oil pipe, thereby ensuring that the contact surface of the sealing ring 5 with the inner wall of the oil pipe at all locations around the circumference is balanced, thereby ensuring the sealing effect. On the other hand, after the cover plate 1 is set, even if the edge of the sealing ring 5 leaks locally during the pressurization process, causing liquid to spray outward, the cover plate 1 can be used to block the sprayed liquid, preventing the sprayed high-pressure liquid from causing harm to personnel and damaging the surrounding environment; if the sealing ring 5 is regarded as the first sealing structure and is used to form a circumferential seal, then the cover plate 1 is the second sealing structure and forms an end face seal. To further ensure the effect of the end face seal, a rubber layer can be provided on the surface of the cover plate 1 or a rubber gasket can be provided between the cover plate 1 and the end face of the oil pipe. In this solution, the same sealing component forms two sealing structures at two locations of the oil pipe, which can effectively improve the sealing effect. In addition, the two sealing structures are driven by the same push rod 3, making the process of achieving contact sealing simpler and faster. This solution not only drives the sealing ring 5 to seal the inner wall of the oil pipe while pushing the two sets of plugging components toward the oil pipe, but also achieves the purpose of securing the oil pipe, eliminating the need for a separate clamping mechanism. This can also be understood as utilizing the two sets of plugging components to secure the oil pipe while simultaneously achieving the purpose of plugging the leak, eliminating the need for a separate drive device to drive the push rod 3. During the pressure test, the pressure testing instrument injects liquid into the oil pipe through the liquid injection hole 301 to reach a predetermined pressure value, then maintains the pressure according to the design pressure requirement. The pressure inside the oil pipe is fed back through the pressure testing instrument. If the pressure feedback from the pressure testing instrument decreases, it indicates a leak in the oil pipe.When the pressure test is completed, it is only necessary to move the push rod 3 backward, that is, to the outer end of the oil pipe, to remove the pressing force on the sealing ring 5. The sealing ring 5 will also automatically shrink under the action of the rebound force and release the pressing force of the sealing ring 5 on the inner wall of the oil pipe. In this way, the sealing assembly can be quickly removed from the end of the oil pipe. After the pressure test is completed, the liquid inside the oil pipe can be discharged through the injection hole 301, or the liquid can be allowed to flow out on its own after the sealing assembly is removed.

[0024] Preferably, the end faces of the baffle 21 and the pressure ring 4 abutting the sealing ring 5 are all conical surfaces, and the cone tops are arranged relative to each other. This structural design can use the conical surface to actively guide the sealing ring 5 to expand outward when the baffle 21 and the pressure ring 4 press the sealing ring 5. In this way, the sealing ring 5 can expand outward to a greater extent when the push rod 3 moves forward the same distance, and under the condition that the push rod 3 is subjected to the same thrust, the sealing ring 5 can also have a greater outward expansion amount, thereby reducing the moving stroke or driving pressure of the push rod 3 and reducing the power demand of the driving element 6.

[0025] Preferably, Figure 3 、 Figure 6 and Figure 8 As shown, the baffle 21 and the pressure ring 4 are provided with multiple annular grooves 41 on the end faces for abutting the sealing ring 5. When the sealing ring 5 is squeezed, the materials at both ends thereof will sink into the annular grooves 41, thereby forming a multi-channel sealing ring structure on the end faces where the baffle 21 and the pressure ring 4 abut against the sealing ring 5, so as to further improve the sealing effect.

[0026] Preferably, Figure 6 、 Figure 8 As shown, the distance between the strip hole 22 and the baffle 21 is greater than or equal to the thickness of the sealing ring 5 in its natural state. This allows the sealing ring 5 to be completely located in the solid part of the guide cylinder 2 during sealing, preventing the strip hole 22 and the sealing ring 5 from overlapping during sealing, causing the sealing ring 5 to be squeezed into the strip hole 22, thereby reducing the pressure between the outside of the sealing ring 5 and the oil pipe, and thus reducing the sealing effect. The connecting rod 31 is located on the side of the pressure ring 4 facing the cover plate 1, so that the pressure ring 4 protrudes from the connecting rod 31, thereby preventing the connecting rod 31 from abutting the end of the strip hole 22 when the sealing ring 5 is compressed, thereby affecting the travel of the sealing ring 5.

[0027] Preferably, Figure 6 、 Figure 8 As shown, the sealing ring disposed between the baffle 21 and the outer wall of the push rod 3 has a V-shaped or U-shaped cross-section, with its opening facing the front end of the push rod 3. When the oil pipe is pressurized, liquid enters the open end of the sealing ring, pressing the inner side of the sealing ring inward against the surface of the push rod 3 and the outer side of the sealing ring outward against the wall of the hole in the baffle 21 where the push rod 3 is mounted, thereby achieving the purpose of sealing. The greater the pressure inside the oil pipe, the better the sealing effect between the sealing ring, the baffle 21, and the push rod 3.

[0028] Preferably, combined Figure 3 、 Figure 4 、 Figure 6 and Figure 8 As shown, the rear end of the pressure ring 4 is coaxially provided with a cylindrical section 42 whose outer diameter is smaller than that of the pressure ring 4, and a limiting groove 43 of a circular ring structure is coaxially formed between the cylindrical section 42 and the pressure ring 4. The side of the limiting groove 43 close to the cylindrical section 42 is an inclined surface, and a plurality of claws 11 are provided in a circumferential array on the side of the cover plate 1 facing the pressure ring 4. The claws 11 are provided with a protrusion 111, and the thickness of the protrusion 111 is equal to the difference between the radius of the cylindrical section 42 and the oil pipe. When the claws 11 are clamped in the limiting groove 43, the sealing ring 5 is in a natural state. When the cam 111 is in the closed position, the cam 111 is in the closed position, and the cam 111 is in the closed position, so that the cam 111 is pressed against the inner wall of the oil pipe and the outer wall of the oil pipe is pressed against the outer wall of the oil pipe. When the cam 111 is pressed against the inner wall of the oil pipe, the cam 111 is pressed against the inner wall of the oil pipe and the outer wall of the oil pipe is pressed against the outer wall of the oil pipe. When the cam 111 is pressed against the inner wall of the oil pipe, the cam 111 is pressed against the inner wall of the oil pipe and the inner wall of the oil pipe is pressed against the outer wall of the oil pipe.

[0029] Preferably, Figure 8 As shown, a return spring 32 is sleeved on the front section of the push rod 3, which is located between the connecting rod 31 and the baffle 21, and the return spring 32 is in a compressed state to ensure that after the cover plate 1 is separated from the oil pipe, the return spring 32 is used to push the baffle 21, the guide cylinder 2 and the cover plate 1 to move forward, so that the protrusion 111 is automatically stuck in the limit groove 43, and the pressure ring 4 quickly releases the pressure on the sealing ring 5, so that the sealing ring 5 is quickly retracted to prevent the sealing ring 5 from being scratched during the process of being pulled out of the oil pipe.

[0030] Preferably, Figure 6 、 Figure 8 As shown, the cross-section of the sealing ring 5 is rectangular or isosceles trapezoidal, and multiple circles of contraction grooves 51 are staggered on its outer wall and inner wall to increase the compression and expansion of the sealing ring 5. After compression, the contraction grooves 51 will form a labyrinth sealing structure, which helps to improve the sealing effect.

[0031] Preferably, Figure 1As shown, the old oil pipe pressure test sealing system also includes a rectangular frame 7, which has driving elements 6 at both opposite ends. The movable rods of the driving elements 6 are relatively arranged, and the movable rods of the driving elements 6 are connected to the push rod 3. The scheme enables the two sets of sealing components to be connected as an integral structure through the rectangular frame 7, which is convenient for the overall transfer and installation of the system; as a preferred scheme, the push rod 3 can be welded to the movable rod of the driving element 6 through the outer wall, and this structure allows the injection hole 301 to pass through both ends of the push rod 3; as another preferred scheme, the push rod 3 is coaxially connected to the movable rod, and the injection hole 301 is led out from the side wall of the middle section of the push rod 3, and is connected to the pressure detection instrument through a pipe joint.

[0032] More preferably, Figure 1 As shown, the cover plate 1 is provided with support rods 8 in parallel, and both ends of the support rods 8 extend to the opposite sides of the cover plate 1. The two ends of the support rods 8 are slidably connected to the two parallel side rods of the rectangular frame 7. In this way, the sealing assembly is connected to the rectangular frame 7 through the support rods 8, which not only improves the coaxial accuracy of the two groups of sealing assemblies, but also ensures the installation stability of the sealing assembly and ensures the stability of the disassembly process.

[0033] Preferably, at least two groups of V-shaped support members 9 are provided at the bottom of the rectangular frame 7 for supporting the oil pipe to ensure the coaxial accuracy of the oil pipe and the sealing ring 5 .

[0034] As a further preferred solution, the V-shaped support member comprises a pair of opposing support plates 91, each having an inclined top surface at one end. The two inclined surfaces of the two paired support plates 91 form a V-shaped groove for supporting the oil pipe. The two support plates 91 in the same group are movable along the connecting line to adjust the support height of the oil pipe, thereby accommodating oil pipes of different outer diameters. Furthermore, the V-shaped groove can be opened by moving the support plates 91 outward, facilitating direct blanking from below. Specifically, each support plate 91 is mounted on the movable end of a hydraulic or pneumatic cylinder, which is used to control the movement of the support plates 91.

[0035] As another preferred solution, Figure 2 As shown, the two support plates 91 of the same group are staggered in the width direction, and the opposite sides of the two support plates 91 are respectively provided with mutually cooperating ridges 911 and strip grooves 912. Specifically, the ridge 911 is provided on one of the support plates 91, and the strip groove 912 is opened on the other support plate 91, so as to improve the connection strength and support strength between the support plates 91 of the same group.

[0036] The above description is only a preferred embodiment of the present invention and is not intended to be the only one or to limit the present invention. It should be understood by those skilled in the art that various changes or equivalent replacements made to the present invention without departing from the scope of the present invention are within the scope of protection of the present invention.

Claims

1. A pressure test sealing system for old oil pipes, characterized in that: include: Two sets of blocking components, the blocking components including a cover plate (1) and a push rod (3); The outer diameter of the cover plate (1) is larger than the outer diameter of the oil pipe. A guide cylinder (2) is coaxially provided on one side of the cover plate (1). A baffle (21) with a larger diameter is coaxially provided at the end of the guide cylinder (2). A plurality of strip holes (22) are opened along the circumference of the side wall of the guide cylinder (2), and the length direction of the strip holes is parallel to the axial direction of the guide cylinder (2). A pressure ring (4) and a sealing ring (5) are sleeved on the outside of the guide cylinder (2). The sealing ring (5) is located between the pressure ring (4) and the baffle (21). The outer diameters of the pressure ring (4) and the baffle (21) are both smaller than the inner diameter of the oil pipe. Before the sealing ring (5) is compressed, its outer diameter is smaller than or equal to the inner diameter of the oil pipe. The front end of the push rod (3) coaxially passes through the cover plate (1) and the baffle (21), and a sealing ring is provided between the cover plate (1) and the baffle (21) and the outer wall of the push rod (3). A connecting rod (31) passing through the strip hole (22) is provided at the front end of the push rod (3) toward the outside. The outer end of the connecting rod (31) is connected to the pressure ring (4). A liquid injection hole (301) is opened inside the push rod (3) along the axial direction for injecting liquid into the oil pipe. The liquid injection hole (301) is connected to an external pressure detection instrument. The two groups of blocking assemblies are provided with baffles (21) at one end thereof which are arranged opposite to each other and coaxially. The blocking assemblies are also provided with a driving element (6) for directly driving the push rod (3) to move along the axial direction.

2. The old oil pipe pressure test sealing system according to claim 1, characterized in that: The end faces of the baffle (21) and the pressure ring (4) abutting against the sealing ring (5) are all conical surfaces, and the cone tops are arranged opposite to each other.

3. The old oil pipe pressure test sealing system according to claim 1, characterized in that: The baffle (21) and the pressure ring (4) are provided with a plurality of annular grooves (41) on their end surfaces for contacting the sealing ring (5).

4. The old oil pipe pressure test sealing system according to claim 1, characterized in that: The distance between the strip hole (22) and the baffle (21) is greater than or equal to the thickness of the sealing ring (5) in its natural state, and the connecting rod (31) is located on the side of the pressure ring (4) facing the cover plate (1).

5. The old oil pipe pressure test sealing system according to claim 1, characterized in that: The sealing ring disposed between the baffle (21) and the outer wall of the push rod (3) has a V-shaped or U-shaped cross-section, and its opening faces the front end of the push rod (3).

6. The old oil pipe pressure test sealing system according to claim 1, characterized in that: A cylindrical section (42) with a smaller outer diameter is coaxially provided at the rear end of the pressure ring (4), and a limiting groove (43) with a circular ring structure is coaxially formed between the cylindrical section (42) and the pressure ring (4). The side of the limiting groove (43) close to the cylindrical section (42) is an inclined surface. A plurality of claws (11) are provided along a circumferential array on the side of the cover plate (1) facing the pressure ring (4). The claws (11) are provided with a protrusion (111). The thickness of the protrusion (111) is equal to the difference between the radius of the cylindrical section (42) and the oil pipe. When the claws (11) are clamped in the limiting groove (43), the sealing ring (5) is in a natural state.

7. The old oil pipe pressure test sealing system according to claim 6, characterized in that: The front section of the push rod (3) is sleeved with a return spring (32), which is located between the connecting rod (31) and the baffle (21), and the return spring (32) is in a compressed state.

8. The old oil pipe pressure test sealing system according to claim 1, characterized in that: The cross section of the sealing ring (5) is rectangular or isosceles trapezoidal, and the outer wall and the inner wall thereof are staggered with multiple circles of shrinkage grooves (51).

9. The old oil pipe pressure test sealing system according to claim 1, characterized in that: It also includes a rectangular frame (7), with driving elements (6) provided at both opposite ends. The movable rods of the driving elements (6) are arranged opposite to each other, and the movable rods of the driving elements (6) are connected to the push rod (3).

10. The old oil pipe pressure test sealing system according to claim 9, characterized in that: The cover plate (1) is provided with support rods (8) in parallel, with both ends of the support rods (8) extending to opposite sides of the cover plate (1), and both ends of the support rods (8) being slidably connected to two parallel side rods of the rectangular frame (7).

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