Hydraulic accelerator with long service life

Abstract

The invention discloses a long-life hydraulic accelerator, which belongs to the technical field of speed-increasing and efficiency-improving tools in the petroleum drilling industry and comprises a mandrel, an oil cavity is arranged between the mandrel and an upper joint, an upper cylinder sleeve and a middle cylinder sleeve, the upper joint is provided with an automatic pressure relief mechanism, and the oil cavity is communicated with the automatic pressure relief mechanism. The automatic pressure relief mechanism comprises a pressure relief hole, a pressure relief groove, a sealing rod and an oil discharge hole, the pressure relief groove is communicated with the oil cavity through the pressure relief hole, the oil discharge hole is communicated with the pressure relief groove, and the sealing rod is arranged in the pressure relief groove and is provided with a first position for opening the pressure relief hole and a second position for closing the pressure relief hole. The design can effectively relieve the high temperature condition caused by high oil pressure of the hydraulic accelerator, reduce the probability of metal thermal deformation fatigue strength reduction, and prolong the service life of the hydraulic accelerator.

Description

Technical Field

[0001] The invention relates to a long-life hydraulic accelerator, belonging to the technical field of speed-up and efficiency-improving tools in the oil drilling and production industry. Background Art

[0002] The accelerator is usually used in conjunction with the jar and connected above the jar. It is effective in deep directional wells, horizontal wells or shallow wells with limited drill string extension where the well is deep and the friction resistance is large. The accelerator accelerates the impact of the jar connected below to obtain a greater shock force on the stuck point. It is always under load and works reciprocatingly for a long time. The increase in oil temperature causes the performance of the seal to deteriorate or fail. The increase in oil temperature in the oil chamber also causes the oil chamber pressure to increase. At the same time, the metal thermal deformation fatigue strength is reduced, and the life of the high-life hydraulic accelerator is shortened. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a long-life hydraulic accelerator.

[0004] The present invention provides a long-life hydraulic accelerator, comprising a core shaft, an upper joint, an upper cylinder sleeve, a middle cylinder sleeve, a pressure cap and a lower joint which are installed in sequence, an oil chamber is arranged between the core shaft and the upper joint, the upper cylinder sleeve and the middle cylinder sleeve, the upper joint is provided with an automatic pressure relief mechanism, the oil chamber is communicated with the automatic pressure relief mechanism, the automatic pressure relief mechanism comprises a pressure relief hole, a pressure relief groove, a sealing rod and an oil drain hole, the pressure relief groove is communicated with the oil chamber through the pressure relief hole, the oil drain hole is communicated with the pressure relief groove, the sealing rod is arranged in the pressure relief groove and has a first position for opening the pressure relief hole and a second position for closing the pressure relief hole.

[0005] Furthermore, a plugging rod is threadedly connected to the inner surface of the pressure relief groove, and the sealing rod has a connecting groove. The plugging rod is inserted into the connecting groove and abuts against the sealing rod through a disc spring.

[0006] Furthermore, the sealing rod has a first oil inlet hole and a first oil outlet hole connected to the connecting groove, and the first oil outlet hole is connected to the oil drain hole.

[0007] Furthermore, the screw plugging rod is provided with an oil passage chamber, and the oil passage chamber also has a second oil inlet hole and a second oil outlet hole. When the sealing rod is located at the first position, the second oil inlet hole is connected to the first oil inlet hole, and the second oil outlet hole is connected to the first oil outlet hole.

[0008] Furthermore, a filter plug is provided in the oil drain hole.

[0009] Furthermore, an oil storage tank is provided between the core shaft and the upper joint.

[0010] Furthermore, a first stress relief groove is provided on the core shaft.

[0011] Furthermore, a shock pad is provided in the middle cylinder sleeve, the shock pad is connected to the middle cylinder sleeve by threads, the tail of the shock pad is threadedly connected to the pressure cap, a V-shaped combined seal and a retaining ring are provided between the shock pad and the pressure cap, and an O-ring and a retaining ring are provided between the shock pad, the pressure cap and the middle cylinder sleeve.

[0012] By adopting the above technical scheme, the advantage of the present invention is that after the long-life hydraulic accelerator has reciprocated for a certain period of time, since the oil pressure in the long-life hydraulic accelerator is greater than that in the outside, as the oil temperature increases, the oil volume increases, and the oil pressure also increases. When the designed oil pressure value is exceeded, the oil flows into the pressure relief hole and pushes the sealing rod, so that the sealing rod is located in the first position, and the high-pressure oil will enter the pressure relief groove and flow out from the oil drain hole connected to the pressure relief groove. When the pressure relief ends, the oil pressure in the oil chamber is restored, and the sealing rod is located in the second position to block the pressure relief hole. This design can effectively alleviate the high temperature caused by the high oil pressure of the hydraulic accelerator, reduce the probability of reduced metal thermal deformation fatigue strength, and extend the life of the hydraulic accelerator. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a cross-sectional view of the long-life hydraulic accelerator; Figure 2 for Figure 1 Partial cross-sectional view of the middle CC plane; Figure 3 A cross-sectional view of the shock pad portion of the long-life hydraulic accelerator; Figure 4 It is a partial structural schematic diagram of the core shaft of the long-life hydraulic accelerator; Figure 5 It is a partial structural schematic diagram of the upper cylinder sleeve of the long-life hydraulic accelerator; In the figure: core shaft 1, upper joint 2, upper cylinder sleeve 3, middle cylinder sleeve 4, pressure cap 5, lower joint 6, oil chamber 7, pressure relief hole 8, pressure relief groove 9, sealing rod 10, oil drain hole 11, screw plug rod 12, connecting groove 13, disc spring 14, first oil inlet hole 15, first oil outlet hole 16, oil chamber 17, second oil inlet hole 18, second oil outlet hole 19, filter plug 20, oil storage groove 21, first stress relief groove 22, second stress relief groove 23, shock pad 24, O-ring and retaining ring 25, V-shaped combination seal and retaining ring 26. DETAILED DESCRIPTION

[0014] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0015] The terms "first", "second", etc. (if any) in the specification and claims of the present invention are used to distinguish similar objects, rather than to describe a specific order or sequence. Even if "second" is used to distinguish before a certain technical feature, it does not necessarily indicate that "first" is present. It should be understood that in the present invention, "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. It should be understood that in the present invention, "multiple" refers to two or more. "And / or" is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, X and / or Y can represent: X exists alone, X and Y exist at the same time, and Y exists alone. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "Including X, Y and Z", "Including X, Y, Z" means that X, Y, and Z are all included, "Including X, Y or Z" means that one of X, Y, and Z is included, and "Including X, Y and / or Z" means that any one, any two, or three of X, Y, and Z are included.

[0016] like Figures 1 to 5 As shown, the present invention provides a long-life hydraulic accelerator, including a core shaft 1, an upper joint 2, an upper cylinder sleeve 3, a middle cylinder sleeve 4, a pressure cap 5 and a lower joint 6 installed in sequence, an oil chamber 7 is provided between the upper joint 2 and the upper cylinder sleeve 3, the upper joint 2 is provided with an automatic pressure relief mechanism, the oil chamber 7 is connected with the automatic pressure relief mechanism, the automatic pressure relief mechanism includes a pressure relief hole 8, a pressure relief groove 9, a sealing rod 10 and an oil discharge hole 11, the pressure relief groove 9 is connected with the oil chamber 7 through the pressure relief hole 8, the oil discharge hole 11 is connected with the pressure relief groove 9, the sealing rod 10 is arranged in the pressure relief groove 9 and has a first position for opening the pressure relief hole 8 and a second position for closing the pressure relief hole 8.

[0017] According to the present invention, after the long-life hydraulic accelerator has reciprocated for a certain period of time, since the oil pressure in the long-life hydraulic accelerator is greater than that in the outside, as the oil temperature increases, the oil volume increases, and the oil pressure also increases. When the designed oil pressure value is exceeded, the oil flows into the pressure relief hole 8 and pushes the sealing rod 10, so that the sealing rod 10 is located in the first position, and the high-pressure oil will enter the pressure relief groove 9 and flow out from the oil drain hole 11 connected to the pressure relief groove 9. When the pressure relief ends, the oil pressure in the oil chamber 7 is restored, and the sealing rod 10 is located in the second position, blocking the pressure relief hole 8. This design can effectively alleviate the high temperature caused by the high oil pressure of the hydraulic accelerator, reduce the probability of reduced fatigue strength of metal thermal deformation, and extend the life of the hydraulic accelerator.

[0018] Among them, in this embodiment, in order to facilitate the high-pressure oil to push the sealing rod 10, the sealing rod 10 is designed in an inverted cone shape, and the tip of the cone is inserted into the pressure relief hole 8. When the high-pressure oil flows into the pressure relief hole 8, the high-pressure oil can move along the two cone edges toward the pressure relief groove 9, making it convenient for the high-pressure oil to push the sealing rod 10.

[0019] Specifically, a screw rod 12 is connected to the inner thread of the pressure relief groove 9, and the sealing rod 10 has a connecting groove 13. The screw rod 12 is inserted into the connecting groove 13 and abuts against the sealing rod 10 through a disc spring. The screw rod 12 serves as a fixed rod and abuts against the sealing rod 10 through a disc spring 14. It can serve as a lever point for the sealing rod 10 so that the sealing rod 10 can complete the switching between the first position and the second position.

[0020] Specifically, the sealing rod 10 has two first oil inlet holes 15 and a first oil outlet hole 16 connected to the connecting groove 13 , and the first oil outlet hole 15 is connected to the oil drain hole 11 .

[0021] Of course, in order to cooperate with the work of the first oil inlet hole 15 and the first oil outlet hole 16, the screw plug rod 12 is provided with an oil passage chamber 17, and the oil passage chamber 17 also has a second oil inlet hole 18 and a second oil outlet hole 19. When the sealing rod 10 is in the first position, the second oil inlet hole 18 is connected with the first oil inlet hole 15, and the second oil outlet hole 19 is connected with the first oil outlet hole 16.

[0022] A filter plug is provided in the oil drain hole 11. When the automatic pressure relief mechanism stops releasing pressure, the filter plug 20 also prevents foreign matter from entering the interior of the automatic pressure relief mechanism.

[0023] In this embodiment, an oil storage tank 21 is further provided between the core shaft and the upper joint 2. During reciprocating operation, the oil in the oil storage tank 21 can provide a certain surface lubrication for the core shaft 1 to prevent the core shaft from causing dry friction with other components and damaging the surface of the core shaft 1.

[0024] Among them, Figure 4 As shown, the core shaft 1 is also provided with a first stress relief groove 22 to reduce stress concentration during operation. The circular hole on the first stress relief groove 22 has the function of reducing and guiding the impact of air or liquid.

[0025] Understandable, such as Figure 5 As shown, a second stress relief groove 23 is also provided on the upper cylinder sleeve 3. When the long-life hydraulic accelerator rotates, the sharp stress caused by the rotation of the core shaft 1 is reduced. At the same time, the second stress relief groove 23 increases the oil flow area and assists in lubrication to a certain extent.

[0026] The middle cylinder sleeve 4 is provided with a shock pad 24, which is connected to the middle cylinder sleeve 4 by threads, and the tail of the shock pad 24 is threadedly connected to the pressure cap 5, and a V-shaped combined seal and a retaining ring 26 are provided between the shock pad 24 and the pressure cap 5, and an O-ring and a retaining ring 25 are provided between the shock pad 24, the pressure cap 5 and the middle cylinder sleeve 4. The shock pad 24 is used as a limiting part, and the pressure cap 5 performs a secondary reinforcement connection on the shock pad 24, and adopts a V-shaped combined seal and an O-ring for double sealing protection to improve the reliability of the mechanism.

[0027] In addition to the above-mentioned preferred embodiments, the present invention also has other implementation modes. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work are within the scope of protection requested by the present invention.

Claims

1. A long-life hydraulic accelerator, comprising a core shaft (1), an upper joint (2), an upper cylinder sleeve (3), a middle cylinder sleeve (4), a pressure cap (5) and a lower joint (6) which are installed in sequence, characterized in that: An oil chamber (7) is provided between the core shaft (1) and the upper joint (2), the upper cylinder sleeve (3) and the middle cylinder sleeve (4); the upper joint (2) is provided with an automatic pressure relief mechanism; the oil chamber (7) is communicated with the automatic pressure relief mechanism; the automatic pressure relief mechanism comprises a pressure relief hole (8), a pressure relief groove (9), a sealing rod (10) and an oil discharge hole (11); the pressure relief groove (9) is communicated with the oil chamber (7) via the pressure relief hole (8); the oil discharge hole (11) is communicated with the pressure relief groove (9); the sealing rod (10) is arranged in the pressure relief groove (9) and has a first position for opening the pressure relief hole (8) and a second position for closing the pressure relief hole (8).

2. The long-life hydraulic accelerator according to claim 1 is characterized in that: The pressure relief groove (9) is internally threadedly connected to a plugging rod (12), the sealing rod (10) has a connecting groove (13), the plugging rod (12) is inserted into the connecting groove (13) and abuts against the sealing rod (10) via a disc spring (14).

3. The long-life hydraulic accelerator according to claim 2 is characterized in that: The sealing rod (10) has a first oil inlet hole (15) and a first oil outlet hole (16) which are connected to the connecting groove (13); the first oil outlet hole (16) is connected to the oil drain hole (11).

4. The long-life hydraulic accelerator according to claim 3 is characterized in that: The screw plug rod (12) is provided with an oil passage chamber (17), and the oil passage chamber (17) further has a second oil inlet hole (18) and a second oil outlet hole (19). When the sealing rod (10) is located at the first position, the second oil inlet hole (18) is communicated with the first oil inlet hole (15), and the second oil outlet hole (19) is communicated with the first oil outlet hole (16).

5. The long-life hydraulic accelerator according to claim 1 is characterized in that: A filter plug (20) is provided in the oil drain hole (11).

6. The long-life hydraulic accelerator according to claim 1, characterized in that: An oil storage tank (21) is also provided between the core shaft (1) and the upper joint (2).

7. The long-life hydraulic accelerator according to claim 1 is characterized in that: The core shaft (1) is also provided with a first stress relief groove (22).

8. The long-life hydraulic accelerator according to claim 1, characterized in that: A shock pad (24) is provided in the middle cylinder sleeve (4), the shock pad (24) is connected to the middle cylinder sleeve (4) by means of a thread, the rear end of the shock pad (24) is threadedly connected to the pressure cap (5), a V-shaped combined seal and a retaining ring (26) are provided between the shock pad (24) and the pressure cap (5), and an O-ring and a retaining ring (25) are provided between the shock pad (24), the pressure cap (5) and the middle cylinder sleeve (4).

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