Non-self-balancing type underground steel wire safety valve

Abstract

The utility model discloses a non-self-balancing type underground steel wire safety valve which is an important tool for guaranteeing safe operation of an oil and gas well. The steel wire safety valve comprises an upper connector, a piston, a flow pipe, a valve plate, a valve seat and the like. Under the condition that an oil pipe safety valve fails, a steel wire can be tripped into the steel wire safety valve and then is set in the seal to serve as a secondary safety valve, and smooth construction operation is guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of underground oil and gas field completion equipment, in particular to a non-self-balancing underground steel wire safety valve. Background Art

[0002] During the completion of underground oil and gas fields, safety devices are usually designed inside the oil and gas wells to prevent accidents. As a type of safety device, safety valves are indispensable. When a fire alarm, a pipeline rupture in the well, or other unnatural accidents occur during the production process, the safety valve can be closed urgently to prevent blowouts and avoid major accidents that cause immeasurable losses. However, when the safety valve also fails, a wire safety valve needs to be inserted inside the safety valve as a secondary safety valve to replace the work of the conventional safety valve.

[0003] When the downhole tubing safety valve fails to work properly due to an unexpected situation, it may incur huge maintenance costs if it is taken out for repair, and it will also affect the progress of the construction work. The process is relatively cumbersome and will consume a lot of manpower and material resources. At this time, inserting a wire safety valve for replacement work will be the best choice.

[0004] Comparing the existing steel wire safety valves, there are great defects in the structural design. There are three aspects of defects that need to be improved urgently. Defect 1: The piston is long, large, and has no flow holes. This aspect will make it difficult for the coaxiality of each step in the piston component to meet the technical requirements, and the processing is difficult. The lack of flow holes will cause a pressure difference between the inside and outside of the piston. In addition, due to the spring elastic force and its own volume, a large hydraulic pressure is required to push it, which will cause cost waste and increase the difficulty of work; Defect 2: The common steel wire safety valve structural design is unreasonable for assembly and installation. Most steel wire safety valves are to put the spring on the piston step, and then put the spring cylinder on the piston, and use the steps inside the spring cylinder to squeeze the spring until the spring cylinder is completely connected to the connector. This aspect will make it difficult to buckle the spring cylinder and the connector. Buckling under the condition of overcoming the spring elastic force may cause thread biting and cause the parts to be scrapped. It may also cause the piston to be scratched, causing the reciprocating motion of the spring to be not smooth, or even the spring to fail. This structural design also has huge safety hazards for assembly operators. Defect 3: Because the valve plate and valve seat need to be tightly sealed, they must be manually ground. At present, the common wire safety valve connector and valve seat are integrated, which saves the processing route, but it is quite difficult to manually grind them later. The parts themselves are heavy and long, and manual grinding is difficult to ensure uniform force at multiple angles. Once the grinding force of the two parts is not well controlled, resulting in mismatch of the parts, the valve plate and valve seat will be directly scrapped. Utility Model Content

[0005] The utility model aims to provide a non-self-balancing downhole wireline safety valve to solve the problems raised in the above background technology.

[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0007] A non-self-balancing downhole steel wire safety valve includes: an upper joint, a spring cylinder, a valve body assembly, a piston, and a flow tube, wherein the lower end of the upper joint is connected to the spring cylinder by a thread, and the lower thread of the spring cylinder is connected to the valve body assembly by a thread. A piston is arranged inside the upper joint, and the lower part of the piston is connected to the flow tube. A spring, a retaining ring and a C-ring are sleeved on the outside of the flow tube, and the C-ring is inserted into the slot inside the spring cylinder to limit the spring.

[0008] As a further implementation of the utility model, the valve body assembly includes: a valve seat, a valve sleeve, a sealing ring, a fixing screw, a pin shaft, a torsion spring and a valve plate; the upper end of the valve seat is connected to the lower end of the spring tube, and a fourth back ring and a fourth O-ring are provided on the sealing surface of the valve seat and the spring tube, the lower end of the valve seat is connected to the valve sleeve, the valve plate is fixed in the valve sleeve by a pin shaft, the torsion spring is sleeved on the pin shaft, and both ends of the pin shaft are fixed by fixing screws.

[0009] As a further implementation of the utility model, an O-ring groove is provided at the upper end of the valve seat, a fourth back ring and a fourth O-ring are provided in the O-ring groove, a second upper thread is provided below the O-ring groove, the valve seat is connected to the spring tube via the second upper thread, a second lower thread is provided at the lower end of the valve seat, and a third sealing groove is provided at the lower part of the second lower thread.

[0010] As a further embodiment of the utility model, the upper end of the inner tube of the valve sleeve is provided with an internal thread, the internal thread is connected to the second lower thread, and the upper end of the internal thread is provided with a screw hole. The outer end of the valve sleeve is provided with a groove, an extended end of the torsion spring is embedded in the groove, the lower part of the groove is provided with a through hole from the side, the pin is arranged in the through hole, the two sides of the through hole are provided with first threaded holes, and the fixing screws are installed in the first threaded holes.

[0011] As a further implementation method of the utility model, the upper end of the piston is a smooth sealing surface, which is sealed with the inside of the upper joint. The lower end of the piston is provided with a second sealing groove, which forms a seal with the inner wall of the spring tube. A flow hole is opened at the lower end of the second sealing groove, and a connecting thread is provided inside the rear end of the piston, which is connected to the flow tube.

[0012] As a further implementation mode of the present utility model, a first upper thread is provided at the upper end of the upper joint, a first sealing groove is provided inside the upper joint, a first back ring and a first O-ring are installed in the first sealing groove, a punching hole is provided below the first sealing groove, a V-shaped packing is provided on the outer side of the lower end of the upper joint, a first lower thread is provided at the bottom of the upper joint, and the first lower thread is connected to the spring tube.

[0013] As a further implementation of the present utility model, a third upper thread is provided at the upper end of the spring barrel, and the third upper thread cooperates with the first lower thread. An upper screw hole is opened at the top of the third upper thread, and a set screw is installed in the upper screw hole. A fourth sealing groove is provided below the third upper thread, and the fourth sealing groove cooperates with the sealing surface at the lower end of the upper joint. A spring groove is opened inside the spring barrel, and a spring is installed in the spring groove. A retaining ring groove is provided at the lower end of the spring groove, and a C-shaped ring is installed in the retaining ring groove to fix the spring. A third lower thread is provided at the lower part of the retaining ring groove, and a second threaded hole is still opened at the tail end of the lower thread, and a set screw is installed in the second threaded hole.

[0014] The utility model is beneficial in that:

[0015] 1. The piston and the flow tube are made into a split type. The piston is provided with a sealing section to seal the hydraulic pressure. A flow hole is opened at the lower end of the seal to keep the internal and external pressures of the piston balanced, eliminate the pressure caused by the internal and external pressure difference, and make the opening and closing of the safety valve easier.

[0016] 2. When assembling the spring, you can directly install the spring into the spring barrel, and put the retaining ring and C-ring in sequence, and then use the special spring compression tooling to compress the spring until the C-ring is successfully inserted into the spring barrel groove, and then slowly release the spring. At this time, the spring barrel and spring can be installed as a sub-assembly, which solves the problem of laborious buckling and reduces the risk of damage to parts.

[0017] 3. The intermediate connector is eliminated, and the valve seat is directly connected to the spring cylinder through a threaded form, which reduces the length and volume of the valve seat and allows for better manual grinding. In addition, a sealing ring is added to the contact area between the valve seat and the valve plate, which increases the sealing effect and can also play a buffering role during the closing process of the valve plate, making it less likely to damage the sealing surface.

[0018] Other features and advantages of the present invention will be disclosed in detail in the following specific implementations and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of the overall structure for implementing the utility model;

[0020] Figure 2 A cross-sectional view of the overall structure for implementing the utility model;

[0021] Figure 3 A cross-sectional view of the upper joint structure for implementing the utility model;

[0022] Figure 4 A sectional view of a piston structure for implementing the utility model;

[0023] Figure 5 A cross-sectional view of a valve seat structure for implementing the utility model;

[0024] Figure 6 A schematic diagram of the valve sleeve structure for implementing the utility model;

[0025] Figure 7 It is a cross-sectional view of the spring tube structure for implementing the utility model.

[0026] List of reference numerals: upper joint 1, piston 2, first back ring 3, first O-ring 4, set screw 5, second back ring 6, second O-ring 7, third back ring 8, third O-ring 9, spring tube 10, flow tube 11, spring 12, retaining ring 13, C-ring 14, fourth back ring 15, fourth O-ring 16, valve seat 17, valve sleeve 18, sealing ring 19, fixing screw 20, pin 21, torsion spring 22, valve plate 23, packing 24, dust plug 25, first upper thread 101, first sealing groove 102, pressure hole 103, First lower thread 104, second sealing groove 201, through hole 202, connecting thread 203, screw hole 1801, groove 1802, internal thread 1803, through hole 1804, first threaded hole 1805, O-ring groove 1701, second upper thread 1702, second lower thread 1703, third sealing groove 1704, upper screw hole 1001, third upper thread 1002, fourth sealing groove 1003, spring groove 1004, retaining ring groove 1005, third lower thread 1006, second threaded hole 1007. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model. Embodiment 1:

[0028] In conjunction with the accompanying drawings, the assembly method of the non-self-balancing wire safety valve disclosed in the present application is described in detail;

[0029] 1. First, install all seals into the corresponding sealing grooves or insert them into the corresponding sealing surface positions;

[0030] 2. Place the spring 12 and retaining ring 13 into the spring groove 1004 of the spring tube 10, use a special spring compression tool to compress the spring until the retaining ring groove 1005 is exposed, and use retaining ring pliers to install the C-ring 14 into the retaining ring groove 1005.

[0031] 3. At this time, slowly retract the spring compression tooling to slowly reset the spring 12 until it is fixed in the spring tube 10, forming a spring tube assembly;

[0032] 4. Connect the piston 2 and the flow tube 11 together through threads, and then insert them into the inner hole of the upper joint 1 together to form an upper joint subassembly;

[0033] 5. At this time, connect the installed upper joint sub-assembly to the spring tube sub-assembly through threads, and set aside after the connection is completed.

[0034] 6. Grind the sealing surface of the valve plate 23 and the valve seat 17 with grinding paste. After grinding to the specified standard, prepare for installation;

[0035] 7. Align the valve plate 23 with the through hole 1804 on the valve sleeve 18, use a special torsion spring wrench to fix the torsion spring 22, and then insert the pin 21 into the through hole 1804 to fix the torsion spring.

[0036] 8. Then install the fixing screws 20 into the first threaded holes 1805 on the left and right sides of the valve sleeve 18 to prevent the pin from slipping off;

[0037] 9. Connect the second lower thread 1703 at the rear end of the valve seat 17 with the internal thread 1803 at the top end of the valve sleeve 17 so that the two pieces are connected together to form a valve body assembly.

[0038] 10. Connect the valve body assembly to the third lower thread 1006 at the rear end of the spring tube 10, and then tighten all the set screws 5.

[0039] 11. The non-self-balancing wire safety valve is assembled.

[0040] Compared with the existing steel wire safety valve, the advantages of this application in terms of assembly procedure are:

[0041] (1) It can greatly shorten the installation time and improve the delivery efficiency;

[0042] (2) There are no potential safety hazards during assembly, and the safety performance is very reliable.

[0043] (3) The number of parts in the present application is less than that of previous wire safety valves, which reduces machining time and greatly saves costs. Embodiment 2:

[0044] The method for using the non-self-balancing wire safety valve of the present application is described in detail with reference to the accompanying drawings;

[0045] 1. The first upper thread 101 of the upper joint 1 of the steel wire safety valve is connected to the extension tube, and the upper end of the extension tube is connected to the locking mandrel. The steel wire safety valve is seated into the oil pipe safety valve using a running tool. The sealing assembly on the locking mandrel is sealed on the sealing surface of the upper joint of the oil pipe safety valve, and the packing on the steel wire safety valve is sealed on the sealing surface of the lower joint of the oil pipe safety valve. At this time, the steel wire safety valve can closely cooperate with the sealing surfaces of the upper and lower joints of the oil pipe safety valve to form a seal.

[0046] 2. After completing the above operations, directly inject hydraulic pressure through the hydraulic control line of the oil pipe safety valve, and the liquid pressure is transmitted through the pressure hole 103 of the steel wire safety valve.

[0047] 3. When the liquid pressure is greater than the elastic force of the spring 12, the piston 2 drives the flow tube to advance slowly.

[0048] 4. Continue to increase the hydraulic pressure so that the flow tube 11 overcomes the elastic force of the torsion spring 22 and pushes open the valve plate 23 until the valve plate 23 is fully opened.

[0049] 5. Then slowly release the pressure, when the hydraulic pressure is less than the pressure of the spring 12, the piston 2 and the flow tube 11 are gradually reset by the elastic force of the spring 12. The valve plate 23 is closed by the reaction force of the torsion spring 22.

[0050] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-restrictive from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention. Any reference numeral in a claim should not be regarded as limiting the claim to which it relates.

[0051] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A non-self-balancing downhole wireline safety valve, characterized in that: include: Upper connector (1), spring cylinder (10), valve body assembly, piston (2), flow tube (11), The lower end of the upper joint (1) is connected to the spring barrel (10) by means of a thread, the lower thread of the spring barrel (10) is connected to the valve body assembly by means of a thread, a piston (2) is provided inside the upper joint (1), the lower part of the piston (2) is connected to the flow tube (11), the outer part of the flow tube (11) is covered with a spring (12), a retaining ring (13) and a C-shaped ring (14), and the C-shaped ring (14) is inserted into a groove inside the spring barrel (10) to limit the spring (12).

2. A non-self-balancing downhole wireline safety valve according to claim 1, characterized in that: The valve body assembly comprises: a valve seat (17), a valve sleeve (18), a sealing ring (19), a fixing screw (20), a pin (21), a torsion spring (22) and a valve plate (23); The upper end of the valve seat (17) is connected to the lower end of the spring tube (10), and a fourth back ring (15) and a fourth O-ring (16) are provided on the sealing surface between the valve seat (17) and the spring tube (10). The lower end of the valve seat (17) is connected to the valve sleeve (18), the valve plate (23) is fixed in the valve sleeve (18) by means of a pin shaft (21), the torsion spring (22) is sleeved on the pin shaft (21), and both ends of the pin shaft (21) are fixed by means of fixing screws (20).

3. A non-self-balancing downhole wireline safety valve according to claim 2, characterized in that: An O-ring groove (1701) is provided at the upper end of the valve seat (17), and a fourth backing ring (15) and a fourth O-ring (16) are provided in the O-ring groove (1701). A second upper thread (1702) is provided below the O-ring groove (1701), and the valve seat (17) is connected to the spring tube (10) via the second upper thread (1702). A second lower thread (1703) is provided at the lower end of the valve seat (17), and a third sealing groove (1704) is provided at the lower portion of the second lower thread (1703).

4. A non-self-balancing downhole wireline safety valve according to claim 3, characterized in that: The upper end of the inner tube of the valve sleeve (18) is provided with an internal thread (1803), and the internal thread (1803) is connected to the second lower thread (1703). The upper end of the internal thread (1803) is provided with a screw hole (1801). The outer end of the valve sleeve (18) is provided with a groove (1802), and an extended end of the torsion spring (22) is embedded in the groove (1802). The lower part of the groove (1802) is provided with a through hole (1804) from the side. The pin shaft (21) is arranged in the through hole (1804), and first threaded holes (1805) are provided on both sides of the through hole (1804). Fixing screws (20) are installed in the first threaded hole (1805).

5. A non-self-balancing downhole wireline safety valve according to claim 1, characterized in that: The upper end of the piston (2) is a smooth sealing surface, which is sealed with the interior of the upper joint (1). The lower end of the piston (2) is provided with a second sealing groove (201), which forms a seal with the inner wall of the spring tube (10). The lower end of the second sealing groove (201) is provided with a flow hole (202). The rear end of the piston (2) is provided with a connecting thread (203), which is connected to the flow tube (11).

6. A non-self-balancing downhole wireline safety valve according to claim 1, characterized in that: The upper end of the upper joint (1) is provided with a first upper thread (101), the interior of the upper joint (1) is provided with a first sealing groove (102), a first backing ring (3) and a first O-ring (4) are installed in the first sealing groove (102), and a punching hole (103) is provided below the first sealing groove (102). A V-shaped packing (24) is provided on the outer side of the lower end of the upper joint (1), and a first lower thread (104) is provided on the bottom of the upper joint (1), wherein the first lower thread (104) is connected to the spring tube (10).

7. A non-self-balancing downhole wireline safety valve according to claim 6, characterized in that: The upper end of the spring tube (10) is provided with a third upper thread (1002), the third upper thread (1002) cooperates with the first lower thread (104), an upper screw hole (1001) is formed at the top of the third upper thread (1002), a set screw (5) is installed in the upper screw hole (1001), A fourth sealing groove (1003) is provided below the third upper thread (1002), and the fourth sealing groove (1003) cooperates with a sealing surface at the lower end of the upper joint (1). The spring tube (10) has a spring groove (1004) formed inside, a spring (12) being installed in the spring groove (1004), a snap ring groove (1005) being provided at the lower end of the spring groove (1004), a C-shaped ring (14) being installed in the snap ring groove (1005) to fix the spring, a third lower thread (1006) being provided at the lower portion of the snap ring groove (1005), a second threaded hole (1007) still being formed at the tail end of the lower thread, a set screw (5) being installed in the second threaded hole (1007).

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