Reverse impact hydraulic down-the-hole hammer

Abstract

This invention relates to the field of drilling machinery technology, specifically a reverse impact hydraulic down-the-hole hammer. Its external structure consists of an upper connector, a housing, and a lower connector rigidly connected together. Within this external structure is a valve-hammer mechanism, integrally fitted together with a hammer body, piston, sleeve valve, and valve seat. This invention maintains the working fluid flow from the wellhead to the bottom of the well while the impact hammer impacts from the bottom of the well towards the wellhead. It can penetrate hundreds or even thousands of meters deep into wells, driven by drilling fluid under significant hydraulic pressure, converting hydraulic energy into impact energy that acts on the drilling tools. It is primarily used in geological drilling, oil drilling, water well drilling, and mining drilling for stuck or buried drill bits; for retrieving stuck casing or piles; for closed-circuit reverse circulation impact rotary drilling; for improving the efficiency of reverse reaming drilling; and for various special construction operations requiring impact or rotary impact from downhole to the wellhead.

Description

Technical Field

[0001] This invention relates to the field of drilling machinery technology, and in particular to a reverse impact hydraulic down-the-hole hammer mainly used in geological drilling, oil drilling, water well drilling and mining drilling. Background Technology

[0002] Currently, commonly used hydraulic down-the-hole hammers have various structures and working principles, but their control and execution are all achieved by a valve-hammer mechanism. The impact piston of the valve-hammer mechanism impacts in the direction of fluid flow (forward impact) to perform work, improving drilling efficiency in hard rock; it can also be used in mineral exploration to remove core blockages in the coring tube during coring drilling. However, during drilling operations, hydraulic down-the-hole hammers that require reverse impact (reverse impact) may be encountered, such as in dealing with stuck or buried drill bits in the well. Previously, this was done by driving a hammer upwards from the wellhead to impact the drill string, with the impact energy transmitted from the wellhead to the accident site downhole through the drill string. Due to losses along the way, this method has low transmission efficiency.

[0003] According to existing technology research, there were no reports on hydraulic down-the-hole hammers that perform work by reverse impact (reverse impact) prior to the filing of this application. Summary of the Invention

[0004] To address the shortcomings of the existing technologies, the present invention aims to propose a reverse impact hydraulic down-the-hole hammer. The reverse impact hydraulic down-the-hole hammer (hereinafter referred to as the reverse impact down-the-hole hammer) proposed in this invention is installed on the drill string close to the accident site. In this way, most of the impact energy can be applied to the accident site, which is more conducive to resolving the accident.

[0005] Existing hydraulic down-the-hole hammer (forward impact) technology for drilling is already mature. It typically impacts from top to bottom along the hammer body, that is, from the inlet to the outlet of the down-the-hole hammer. Furthermore, the inlet and outlet ends of the hydraulic down-the-hole hammer cannot be reversed during use, fully meeting the basic requirements for a reverse-impact down-the-hole hammer. Therefore, as long as the fluid flow within the drill string remains constant from top to bottom, while the impact piston reverses the fluid flow direction within the drill string, the reverse-impact hydraulic down-the-hole hammer of this invention can be constructed, achieving the desired technical effect. To achieve reverse impact of the hammer body, it is necessary to improve the valve hammer structure and the connection method between it and other components, changing the valve hammer mechanism from a forward impact state to a reverse impact state.

[0006] This invention is achieved through the following technical solution:

[0007] A reverse impact hydraulic down-the-hole hammer has an external structure consisting of an upper connector, a housing, and a lower connector rigidly connected together. The external structure is fitted with a valve hammer mechanism consisting of a hammer body, a piston, a sleeve valve, and a valve seat. The lower section of the hammer body is connected to the piston. The sleeve valve is fitted between the valve seat and the piston and they are dynamically sealed to each other. The valve seat is rigidly connected to the lower connector. The injector is located between the piston and the lower connector. The enclosed space between the valve hammer mechanism and the upper connector is the upper cavity.

[0008] A central tube, which is dynamically sealed to the hammer body and piston, runs through the central axis of the valve hammer mechanism. The inlet end of the central tube is rigidly connected to the upper connector, and the outlet end of the central tube is inserted into the inner cavity of the injector. Near the outlet end of the central tube, there is a radial liquid passage hole that communicates with the inner cavity of the injector. The inner cavity of the injector is connected to the inner cavity of the piston. During operation, the working fluid entering the upper connector enters the injector through the radial liquid passage hole and is sprayed from the inner cavity of the injector into the inner cavity of the piston, driving the piston and hammer body to repeatedly impact the hammering surface of the upper connector. At the same time, the discharged liquid flows into the lower connector through the discharge channel and is discharged.

[0009] This invention is also achieved through the following technical solutions:

[0010] A reverse impact hydraulic down-the-hole hammer comprises an external structure consisting of an upper connector, a housing, and a lower connector rigidly connected together. Inside the external structure's cavity is a flow-dividing valve-hammer mechanism consisting of a hammer body, a flow-dividing sleeve, a sleeve valve, a valve seat, a piston, a flow-dividing seat, and an injector, all fitted together. The lower part of the hammer body is rigidly connected to the piston. The sleeve valve is fitted between the valve seat and the piston, providing a dynamic seal. The valve seat is connected to the flow-dividing sleeve, the upper end of the flow-dividing sleeve is connected to the upper connector, and the flow-dividing seat is rigidly connected to the lower connector. An injector is installed inside the flow-dividing seat, and the injector's inner cavity communicates with the piston's inner cavity.

[0011] The diverter sleeve and diverter seat divide the drainage channel from the upper connector to the lower connector into two parts: the first part guides the working fluid entering from the upper connector into the inner cavity of the injector located in the diverter seat; the second part guides the working fluid discharged after the sleeve valve is opened into the drain port of the lower connector for discharge. During operation, the working fluid enters the inner cavity of the injector and is sprayed into the inner cavity of the piston. The alternating pressure difference between the upper and lower cavities drives the sleeve valve to continuously open and close, pushing the piston and hammer body to continuously impact the hammering surface of the upper connector upwards. At the same time, the discharged fluid flows into the lower connector for discharge through the drainage channel.

[0012] This invention is also achieved through the following technical solutions:

[0013] A reverse impact hydraulic down-the-hole hammer comprises an external structure consisting of an upper connector, a housing, and a lower connector rigidly connected together. An energy storage valve-hammer mechanism, consisting of a sleeve valve, a piston, a check valve, a valve spring, a hammer spring, a hammer body, and a hammer spring seat, is integrally installed within the cavity of the external structure. The lower end of the hammer spring seat is rigidly connected to the lower connector, and the upper end of the hammer spring seat supports the hammer spring fitted onto the outer surface of the hammer body. A dynamic seal is present between the lower section of the hammer body and the inner wall of the hammer spring seat. The sleeve valve is connected to the upper section of the hammer body and also has a dynamic seal; the sleeve valve contains a valve spring fitted onto the outer surface of the hammer body. When a check valve is placed in the fluid passage running along the central axis of the hammer body, the fluid passage is blocked. This creates a piston cavity in front of the check valve. The working fluid entering through the upper connector accumulates in the piston cavity and flows through the side passage to the lower cavity of the sleeve valve. Under hydraulic pressure, the sleeve valve is pushed and the valve spring is compressed, moving upward to the hammering surface of the upper connector until it is pressed against the hammering surface. After the hammer body end face engages with the hammering surface, the drain channel is closed. The hydraulic pressure in the piston cavity and the lower cavity of the sleeve valve continues to rise. The piston, along with the hammer body, moves downward towards the lower connector, while simultaneously compressing the hammer spring and the valve spring until the valve spring compression force increases to push open the sleeve valve and open the drain channel. At this point, the hammer spring releases energy to push the hammer body, along with the sleeve valve, upward to impact the hammering surface of the upper connector, repeating the reverse impact continuously.

[0014] The working fluid entering the upper connector is directly introduced into the injector located on the lower connector in a sealed state through the central tube, and then injected into the piston cavity through the nozzle.

[0015] The upper and lower connectors are threadedly connected to the upper and lower sections of the outer shell, respectively, to form the external structure.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] This invention is a hydraulic down-the-hole hammer (reverse down-the-hole hammer) that impacts the fluid flow direction inside the drill string. The main uses of this down-the-hole hammer are: (1) handling downhole stuck drill or buried drill accidents; (2) pulling out stuck casing or pile pipe; (3) closed-circuit reverse circulation impact rotary drilling; (4) various special constructions that require impact or rotary impact from downhole to wellhead.

[0018] The reverse down-the-hole hammer proposed in this invention, while maintaining the working fluid flow from the wellhead to the bottom of the well, impacts the hammer body from the bottom of the well towards the wellhead. It is cylindrical in shape with a diameter matching the well diameter, and can be used in wells hundreds or even thousands of meters deep. Under the pressure of a large hydraulic column (back pressure) in the well, it is driven by drilling fluid and converts hydraulic energy into impact energy, which has a large enough impact energy to act on the drill string and has high transmission efficiency. It can be connected to the drill string remaining in the downhole fishing device and can also be disassembled from the connected downhole fishing device drill string. Attached Figure Description

[0019] Figure 1This is a schematic diagram illustrating the structure and principle of Embodiment 1 of the present invention;

[0020] Figure 2 This is a schematic diagram illustrating the structure and principle of Embodiment 2 of the present invention;

[0021] Figure 3 This is a schematic diagram illustrating the structure and principle of Embodiment 3 of the present invention;

[0022] The numbers in the diagram are explained as follows: 1. Upper connector, 2. Central tube, 3. Hammer body, 4. Outer shell, 5. Sleeve valve, 6. Valve seat, 7. Piston, 8. Injector, 9. Lower connector, 10. Diverter sleeve, 11. Diverter seat, 12. Valve spring, 13. Hammer spring, 14. Ball check valve, 15. Hammer spring seat, 20. Upper chamber, 21. Piston inner chamber, 22. Upper limit of valve stroke, 23. Lower limit of valve stroke, 24. Lower chamber, 25. Injector inner chamber, 26. Lower chamber of sleeve valve, 27. Fluid passage. Detailed Implementation

[0023] The technical solutions in this embodiment will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some examples of the present invention, and not all examples. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Example 1

[0025] A reverse impact hydraulic down-the-hole hammer, with the following structure: Figure 1 The external structure is formed by the rigid connection between the upper connector 1, the outer shell 4, and the lower connector 9. The internal cavity of the hydraulic down-the-hole hammer within the external structure is equipped with a valve hammer mechanism consisting of a hammer body 3, a piston 7, a sleeve valve 5, and a valve seat 6 connected together. A central pipe 2, which is dynamically sealed and allows the working fluid to flow, runs through the central axis of the valve hammer mechanism. There is a radial fluid passage near the outlet end of the central pipe 2. The outlet end of the central pipe 2 is directly inserted into the inner cavity 25 of the injector located on the lower connector 9. The working fluid enters the inner cavity 25 of the injector through the radial fluid passage. The entire valve hammer mechanism, together with the central pipe 2, is fitted into the down-the-hole hammer cavity formed by the connection of the upper connector 1, the outer shell 4, and the lower connector 9. The valve seat 6 is connected to the lower connector 9.

[0026] The upper limit 22 and lower limit 23 of the valve travel during operation of the sleeve valve 5 are located on the inner end face of the valve seat 6 and the outer end face of the injector 8, respectively.

[0027] Working process: The working fluid enters the upper connector 1, passes through the central tube 2 and its radial liquid passage at the outlet end, and enters the injector 8. It is then sprayed from the inner cavity 25 of the injector into the inner cavity 21 of the piston. Utilizing the alternating conversion of fluid kinetic energy and pressure energy, the piston 7 and the hammer 3 are driven to continuously impact the upper connector 1 in a reverse direction, striking the hammering surface of the upper connector 1. Simultaneously, the discharged working fluid flows through the upper cavity 20 between the hammer 3 and the external structure and the discharge channel into the lower connector 9 for discharge. The valve hammer mechanism of this invention is installed in a reverse impact state within the cavity of the down-the-hole hammer, and the impact direction of the hammer body during operation is completely opposite to that of a conventional hydraulic down-the-hole hammer.

[0028] Example 2

[0029] A reverse impact hydraulic down-the-hole hammer, with the following structure: Figure 2 It consists of an upper connector 1, a hammer body 3, a housing 4, a flow divider sleeve 10, a sleeve valve 5, a valve seat 6, a piston 7, a flow divider seat 11, an injector 8, and a lower connector 9. Specifically, the hammer body 3, flow divider sleeve 10, sleeve valve 5, valve seat 6, piston 7, flow divider seat 11, and injector 8 are connected together to form a flow divider-type valve hammer mechanism. The impact direction of the hammer body 3 in the flow divider-type valve hammer mechanism is directed towards the upper connector 1, and it is entirely fitted into the downhole hammer cavity formed by the connection of the upper connector 1, the housing 4, and the lower connector 9. There is a surface between the valve seat 6 and the flow divider sleeve 10 that can be joined or separated; the distance between them is the valve stroke.

[0030] Working process: The working fluid enters the upper connector 1, passes through the diverter sleeve 10 and the diverter seat 11 and enters the inner cavity 25 of the injector, and is sprayed into the inner cavity 22 of the piston. The alternating switching of the pressure difference between the upper cavity 20 and the lower cavity 24 drives the sleeve valve 5 in the valve hammer diverter mechanism to continuously open and close the drain valve, pushing the piston 7 and the hammer body 3 to continuously impact the upper connector 1 (reverse impact). At the same time, the fluid discharged from the drain valve enters the lower connector 9 through the drain channel on the diverter sleeve 10 and the diverter seat 11 and is discharged.

[0031] Example 3

[0032] A reverse impact hydraulic down-the-hole hammer, with the following structure: Figure 3It consists of an upper connector 1, a sleeve valve 5, a piston 7, a check valve 14, a valve spring 12, a hammer spring 13, a hammer body 3, a housing 4, a hammer spring seat 15, and a lower connector 9. Specifically, the sleeve valve 5, piston 7, check valve 14, valve spring 12, hammer spring 13, hammer body 3, and hammer spring seat 15 are assembled together to form an energy storage valve hammer mechanism. During assembly, the hammer spring seat 15 compresses the hammer spring 13, forcing the hammering end face of the hammer body 3 to press tightly against the hammering surface of the upper connector 1, blocking the drainage channel. The impact direction of the hammer body 3 faces the upper connector 1. The entire assembly is then installed into the external structure formed by the connection of the upper connector 1, housing 4, and lower connector 9. Before the ball check valve 14 is inserted, the working fluid is discharged directly from the liquid passage 27 inside the hammer body 3 without passing through the sleeve valve 5. The ball check valve 14 must be engaged before starting. Operating Process: First, the check valve 14 is engaged to close the fluid passage 27 inside the hammer body 3. The working fluid entering through the upper connector 1 accumulates in the piston cavity 21 and the lower cavity 26 of the sleeve valve in front of the ball check valve 14, pushing the sleeve valve 5 to compress the valve spring 12 and move it to the hammering surface of the upper connector 1, closing the drain passage. The hydraulic pressure continues to rise, and the piston 7, together with the hammer body 3, moves towards the lower connector 9, simultaneously compressing the hammer spring 13 and the valve spring 12, until the compression force of the valve spring 12 increases to push open the sleeve valve 5, opening the drain passage. At this time, the hammer spring 13 releases energy to push the hammer body 3, together with the sleeve valve 5, to impact the upper connector 1, and the sleeve valve 5 presses tightly against the hammering surface. After the hammer body end face engages with the hammering surface, the working fluid entering the piston cavity 21 will push the sleeve valve 5 towards the hammering surface, blocking the drain passage and forcing the hammer body 3 to return, entering the next working cycle, continuously repeating the reverse impact.

[0033] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A reverse impact hydraulic down-the-hole hammer, characterized in that: The external structure is formed by the rigid connection between the upper connector (1), the outer shell (4) and the lower connector (9). The external structure is fitted with a valve hammer mechanism consisting of a hammer body (3), a piston (7), a sleeve valve (5) and a valve seat (6) connected together. The lower section of the hammer body (3) is connected to the piston (7). The sleeve valve (5) is fitted between the valve seat (6) and the piston (7) and they are dynamically sealed to each other. The valve seat (6) is rigidly connected to the lower connector (9). The injector (8) is located between the piston (7) and the lower connector (9). The closed space between the valve hammer mechanism and the upper connector (1) is the upper cavity (20). A central tube (2) is connected through the central axis of the valve hammer mechanism and is dynamically sealed to the hammer body (3) and piston (7). The inlet end of the central tube (2) is rigidly connected to the upper connector (1), and the outlet end of the central tube (2) is inserted into the inner cavity (25) of the injector. There is a radial liquid passage hole near the outlet end of the central tube (2) that connects to the inner cavity (25) of the injector. The inner cavity (25) of the injector is connected to the inner cavity (21) of the piston. When running, the working fluid entering the upper connector (1) enters the injector (8) through the radial liquid passage hole and is sprayed from the inner cavity (25) of the injector to the inner cavity (21) of the piston, driving the piston (7) and the hammer body (3) to repeatedly impact the hammering surface of the upper connector (1). At the same time, the discharged liquid flows through the discharge channel into the lower connector (9) for discharge.

2. The reverse impact hydraulic down-the-hole hammer according to claim 1, characterized in that: The working fluid entering the upper connector (1) is directly introduced into the injector (8) located on the lower connector (9) in a sealed state through the central tube (2), and then injected into the piston cavity (21) from the nozzle.

3. The reverse impact hydraulic down-the-hole hammer according to claim 1, characterized in that: The upper connector (1) and the lower connector (9) are threadedly connected to the upper and lower sections of the outer shell (4) to form the external structure.

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