A valve-type double-acting hydraulic impactor and method capable of improving working performance

Abstract

The present invention provides a valve-type double-acting hydraulic impactor and method that can improve working performance, including a connecting section, a telescopic section, an impact section, and an external shell; the connecting section is an upper joint, which is used to connect with an upper drill rod; a telescopic section is provided below the upper joint, and the telescopic section includes an upper cylinder sleeve, a limit pad, a live valve, and a piston hammer; the impact section includes an anvil and a drill bit assembly, and the external shell includes an outer shell tube; the live valve is used to interact with a high-pressure driving liquid, reciprocate relative to the outer shell tube, drive the piston hammer to periodically strike the anvil, and the impact work received by the anvil is transmitted to the drill bit assembly connected thereto to impact and break the rock. The present invention includes a valve-type structure composed of a live valve that can both slide and isolate pressure and a piston hammer, so that the live valve and the piston hammer have no rigid collision during the up and down reciprocating motion, reduce useless energy loss, reduce the additional load of the drill bit, improve the rock breaking energy and efficiency of the drill bit, reduce the risk of parts being damaged by rigid collision, and improve the life of the impactor.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas field development, in particular to the technical field of drilling, and specifically to a valve-type double-acting hydraulic impactor and a method for improving working performance. Background Art

[0002] At present, the research on hydraulic impactors has reached a very mature field worldwide. The most widely used hydraulic impactor is the valve-type double-acting hydraulic impactor. The valve-type double-acting hydraulic impactor is the most studied and widely used hydraulic impactor. It is installed on the rotary drill as an auxiliary rock-breaking tool. By changing the rock-breaking mode from cutting to cutting plus impact, it is widely used in geological exploration, oil and gas field development drilling, and drilling. It is conducive to improving drilling efficiency, increasing core recovery rate, preventing broken rock formations from blocking drill tools, increasing drill bit service life, and controlling borehole deviation. It utilizes the pressure difference caused by the area difference or the negative pressure suction effect of the jet to make the live valve reach the upper limit position before the hammer rod. Then the hammer rod moves upward and collides with the live valve to close, closing the water channel, thereby generating a huge water hammer pressure in the upper chamber of the impactor. The water hammer pressure acts on the hammer rod and the upper end surface of the live valve, generating a downward thrust, pushing the hammer rod and the live valve downward together. The live valve stops moving under the action of the lower limit device, and the hammer rod continues to move downward for a free stroke under the action of inertia force before hitting the anvil. This process is repeated to perform impact work.

[0003] From the above working principle, if the hydraulic impactor wants to play the best performance, two conditions must be guaranteed: first, there is no large amount of friction contact, water flow resistance and other energy loss before the piston hammer collides with the anvil, and the pressure of the high-pressure liquid flow is used to the maximum extent; second, it is to ensure that the piston hammer and the live valve will not have rigid collision with each other during normal operation, resulting in energy loss, premature separation and early return. However, in the valve control mechanism of the existing hydraulic impactor technology, the live valve and the hammer adopt a separate structure, and the stroke is a fixed value. After contacting the live valve at the end of the return stroke, a large amount of energy is consumed in the violent collision of the hammer valve, and even the upward impact force is greater than the downward impact force. In actual application, due to the processing matching accuracy, flushing liquid pressure changes, sand content and other reasons, the rigid collision between the hammer and the live valve will consume a lot of energy, resulting in unstable impact frequency, reduced impact work, low water energy utilization, and reduced working performance of the impactor. And the long-term impact and collision of its structure itself will affect the service life, increase the frequency of maintenance and replacement, and increase the cost of use, and fail to achieve the optimal solution. Summary of the invention

[0004] In view of the above problems, the present invention provides a valve-type double-acting hydraulic impactor and method that can improve working performance, so as to solve the technical deficiencies in the existing hydraulic impactor technology, such as the rigid collision of the hammer valve, the instability of the high-pressure liquid flow resulting in the inability of the active valve hammer to work normally, and the unstable performance of the impactor, thereby ensuring that the drill bit breaks rock smoothly, improving the rock breaking energy and efficiency of the drill bit, reducing the risk of parts being damaged by rigid collision, and increasing the life of the impactor and the stability of the entire drilling system.

[0005] In order to achieve the above object, the present invention provides a technical solution as follows:

[0006] A valve-type double-acting hydraulic impactor capable of improving working performance, characterized in that it comprises a connecting section, a telescopic section, an impact section, and an external shell; the connecting section is an upper joint for connecting to an upper drill rod; a telescopic section is provided below the upper joint, the telescopic section comprises an upper cylinder sleeve, a limit pad, a live valve, and a piston hammer; the impact section comprises an anvil and a drill bit assembly, and the external shell comprises an outer shell tube; the live valve is used to interact with a high-pressure driving liquid, reciprocate relative to the outer shell tube, drive the piston hammer to periodically strike the anvil, and the impact work received by the anvil is transmitted to the drill bit assembly connected thereto to impact and break rock; flow channels are provided in the connecting section, the telescopic section, and the impact section to allow the liquid to flow from top to bottom, and the telescopic section is driven by the liquid to move to achieve power transmission to the impact section.

[0007] Furthermore, the middle parts of the upper joint, the upper cylinder sleeve, the limit pad, the live valve, and the piston hammer are all hollow structures, forming a flow channel from top to bottom as a central waterway, and the reciprocating motion is realized by opening and closing the central waterway, and the rock is impacted and broken in the process;

[0008] The live valve is a hollow cylinder, and the outer wall of the live valve includes three sections: upper, middle and lower. The outer wall of the upper section of the live valve is in a dumbbell shape with protruding ends and contracted in the middle, and the outer diameter of the lower shoulder of the upper section is larger than the outer diameter of the upper edge, and the upper and lower ends are clamped in the limit pad, and the limit pad is used to limit the upper and lower displacement limit positions of the live valve; the outer diameter of the middle section of the live valve is larger than that of the lower section, and a flow channel with a side opening is provided at the bottom of the lower section; the upper part of the live valve is sleeved in the inner flow channel of the upper cylinder sleeve;

[0009] The piston hammer is a hollow cylinder that runs through from top to bottom. The inner wall of the piston hammer includes three sections: upper, middle and lower. The inner wall of the upper section of the piston hammer is provided with three steps from top to bottom. The inner diameter of the first section is smaller than the inner diameter of the second section, and the inner diameter of the second section is larger than the inner diameter of the third section, forming an annular cavity. The third section serves as the central water hole of the piston hammer, and the inner diameter of the first section matches the outer diameter of the middle section of the live valve, and the inner diameter of the third section matches the outer diameter of the lower section of the live valve; the inner wall of the middle section of the piston hammer is a straight pipe section as the central liquid flow channel; the lower section of the piston hammer is provided with a horizontal step between the inward-retracted cylindrical section and the central liquid flow channel, and the inward-retracted cylindrical section is provided with a horizontal step. The inner diameter of the cylindrical section is larger than the central liquid flow channel, and the inner wall of the inward-contracted cylindrical section is sleeved on the outside of the anvil; the upper side of the outer wall of the piston hammer is provided with three layers whose diameters increase from top to bottom, and a guide sleeve is provided on the outer side of the upper cylinder sleeve, and a piston hammer guide sleeve is provided below the guide sleeve, and the piston hammer guide sleeve matches the outer diameter of the second layer on the upper side of the outer wall of the piston hammer; at least two lateral throttling holes penetrating the wall of the piston hammer are provided on the side of the central liquid flow channel, and the diameter of the lateral throttling holes is much smaller than the inner diameter of the central liquid flow channel, and there is an annulus between the piston hammer and the outer shell tube as an outer drainage annulus.

[0010] Furthermore, the upper end of the drill bit assembly is connected to the bottom of the anvil, and an upper limit segment of the drill bit is provided on the upper part of the outer diameter surface of the drill bit assembly to ensure that the drill bit assembly will not fall out of the outer casing tube when moving up and down. A spline segment is provided in the middle part of the drill bit assembly, and an internal spline matching the spline segment is provided on the inner side of the outer casing tube to ensure that the drill bit can move up and down along the internal spline so that the drill bit assembly does not rotate. An impact drill bit is provided below the spline segment, and the impact drill bit is located on the lower side of the outer casing tube. The outer diameter of the impact drill bit is larger than the spline segment, and the limit displacement of the drill bit assembly upward is maintained by the step between the impact drill bit and the spline segment.

[0011] Furthermore, the inner wall of the outer shell tube corresponding to the drill bit assembly is provided with a guide bushing, a stop ring and a sleeve in sequence from top to bottom. The sleeve is provided with an internal spline, and the stop ring cooperates with the upper limit segment of the drill bit to limit the downward displacement of the drill bit assembly; the outer side of the sleeve is provided with an external thread, and the bottom of the outer shell tube is provided with an internal thread. The sleeve is fixed to the bottom of the outer shell tube by screwing, and a step is provided inside the lower side of the outer shell tube. When the sleeve is installed in place, the guide bushing is pressed against the step on the lower side of the outer shell tube.

[0012] Furthermore, the bottom of the movable valve is a closed structure, and the flow channel with a side opening above the bottom of the movable valve is used as a lateral drainage hole. The bottom of the annular cavity corresponding to the lateral drainage hole remains close to the bottom of the movable valve in an initial state, and the bottom of the movable valve is provided with a chamfer, and the upper edge of the central water hole of the piston hammer is also provided with a chamfer, so that a gap is maintained between the bottom of the movable valve and the central water hole of the piston hammer in an initial state.

[0013] Furthermore, the anvil includes an upper section whose inner diameter matches the inward-retracted cylindrical section and a lower section whose inner diameter is larger than that of the inward-retracted cylindrical section, and the upper section of the anvil contacts the horizontal step of the inward-retracted cylindrical section, and the step between the lower section of the anvil and the upper section of the anvil contacts the bottom of the piston hammer, and when the piston hammer abuts against the anvil, there are multiple grooves between the horizontal step of the inward-retracted cylindrical section and the top of the anvil, serving as hammer lifting grooves;

[0014] The lower section of the anvil is upwardly provided with a countersink, a step between the lower section of the anvil and the upper section of the anvil is provided with a plurality of outer drainage holes connected to the countersink, and a plurality of drainage holes are provided on the piston hammer corresponding to the outer drainage holes;

[0015] A drill bit center water hole is arranged in the drill bit assembly to receive the liquid sent from the outer drainage hole and discharge it from the impact drill bit.

[0016] Furthermore, the upper joint is connected to the upper inner side of the outer shell tube through a threaded section arranged on the lower side, and a sealing ring is arranged between the upper joint and the outer shell tube; the upper cylinder sleeve is arranged in the guide sleeve, and the upper cylinder sleeve is shorter than the guide sleeve, and the bottom of the guide sleeve is provided with an inwardly contracted step, and a limiting pad is fixed between the upper cylinder sleeve and the guide sleeve through the step, and the limiting pad is an annular structure with an opening on one side, and the width of the open side is the same as the minimum outer diameter of the upper section of the active valve. After the limiting pad is inserted into the active valve, the limiting of the up and down movement is achieved through the active valve.

[0017] A method for hydraulic impact using the valve-type double-acting hydraulic actuator without rigid collision comprises the following steps:

[0018] S1. In the initial state, the piston hammer and the valve are both at the lowest position under the action of gravity;

[0019] S2. The pressure of the liquid input from the top includes a start value and an upper limit value; when the pressure is greater than the upper limit value, the high-pressure liquid sent from the wellhead is sent into the hydraulic impactor through the water inlet of the upper joint of the central drill pipe column, and first enters the inner cavity of the live valve, and flows into the annular cavity formed by the live valve and the piston hammer from the lateral drainage hole at the bottom of the inner cavity. Since the live valve is at the lowest position at this time, the gap between it and the piston hammer is too small to allow a large amount of liquid to enter the central water hole of the piston hammer. The pressure in the annular cavity increases rapidly, forcing the lighter live valve to move upward rapidly until the shoulder of the live valve is blocked by the limit pad;

[0020] After the live valve rises, the flow channel from the annular cavity to the central water hole of the piston hammer opens, and the high-pressure liquid enters the lower end of the central liquid flow channel of the piston hammer. The high-pressure liquid flows out through the lateral throttle hole. However, due to the small size of the lateral throttle hole, it is impossible to discharge all the liquid in the central liquid flow channel in time. At this time, a large amount of liquid is pressed in the central liquid flow channel and acts on the lower surface of the live valve again to lift it. Since the pressure on the upper surface area of ​​the live valve and its own gravity are less than the pressure on the lower surface, the live valve continues to maintain at the upward displacement limit;

[0021] S3, after the pressure in the central liquid flow channel is suppressed, the lifting hammer groove is pressurized, and the entire piston hammer is lifted upward, until the piston hammer rises to the central water hole of the piston hammer and moves to the bottom of the live valve and plugs into each other. At this time, the channel from the annular cavity to the central water hole of the piston hammer is blocked, and the upward movement speed of the piston hammer decreases but does not stop. At this time, after the channel is blocked, the upper part of the live valve is under much greater pressure than the lower part, resulting in a water hammer effect. The live valve quickly moves down to the lowest position, and at the same time, the lower half of the live valve is inserted into the central water hole of the piston hammer, and the piston hammer stops from moving upward and moves downward;

[0022] When the piston hammer moves upward to the limit, the inward-retracted cylindrical section and the anvil are connected to the outer drainage annulus through the outer drainage hole. The high-pressure liquid in the central liquid flow channel flows out from the lateral throttling hole and the outer drainage hole, and enters the central water hole of the drill bit through the leakage hole, and is sprayed out from the spray hole of the impact drill bit to assist in rock breaking and chip removal.

[0023] S4. As the space of the annular cavity decreases and the pressure increases, the piston hammer accelerates downward under pressure and quickly moves to the lowest point to hit the upper surface of the anvil. The anvil evenly transfers the impact force to the drill bit assembly and impacts the drill bit to break the rock. Under the restriction of the spline section, the drill bit assembly only moves axially and does not rotate circumferentially.

[0024] S5. After the piston hammer hits the anvil, the live valve is braked by the limit pad, and after the piston hammer moves to the lowest point, it is restored to its initial position by the reverse thrust of the rock. The live valve and the piston hammer are both at the lowest point, and the situation in S2 appears again. The live valve rises again and waits for the piston hammer to rise again, and then the water hammer effect is generated again to make the piston hammer hit the anvil, realizing hydraulic impact.

[0025] Furthermore, in the aforementioned step S2, when the pressure is less than the limit value and greater than the starting value, after starting, the active valve will not quickly reach the upper limit position, but will stop at some point in the upward movement process under the action of its own weight, overcoming the downward impact force on the convex cone, and the upward pressure of the annular cavity, and will not reach the upper limit position; at the same time, the displacement limit of the piston hammer will also change accordingly, and will not reach the upward displacement limit described in step S2, that is, will turn to downward movement. This situation will not affect normal rock breaking, but will reduce the impact work of rock breaking.

[0026] Compared with the existing hydraulic impactor, the characteristics and advantages of the present invention are:

[0027] 1. The present invention adopts a piston hammer and a movable valve separated structure, which can achieve the whole drill bit without rigid collision of the hammer valve structure during rock breaking drilling, thereby eliminating the possibility that the upward striking force is greater than the downward impact force. The water hammer pressure acts on the force-bearing surface of the annular hammer, and the force-bearing area is small, so that the piston hammer obtains a very high downward impact speed during the stroke movement, improves the energy utilization rate, and thus ensures that the hydraulic impactor drill bit has a sufficiently large impact work, can break rocks smoothly and efficiently, and improves the life of the drill bit and the stability of the entire drilling system.

[0028] 2. There is an annular cavity around the piston hammer to reduce friction loss. There are lateral throttling holes and outer drainage holes at the lower end, which can minimize the weakening of the impact work by the residual liquid flow in the piston hammer and further improve drilling efficiency.

[0029] 3. The present invention adopts the design of upper and lower piston hammer guide sleeves, which can dynamically change the usage mode according to the input high-pressure liquid flow. It has a simple structure, is easy to disassemble and assemble, does not require high processing precision, and saves costs.

[0030] 4. The present invention can realize the conversion between full stroke and partial stroke by adjusting the water pressure so as to adapt to the impact force required by different rock formations. At the same time, it can make more reasonable use arrangement of the drill bit assembly and the valve and prolong the service life.

[0031] 5. The lateral throttle holes and outer drainage holes can relieve pressure when the pressure inside the piston hammer is too high, thus avoiding structural deformation. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the cross-sectional structure of the present invention;

[0033] Figure 2 for Figure 1 The upper schematic diagram of

[0034] Figure 3 for Figure 1 The lower schematic diagram of

[0035] Figure 4 It is a schematic diagram of the hammer valve structure;

[0036] Figure 5 It is a structural schematic diagram of a drill bit assembly;

[0037] Figure 6 It is a schematic diagram of the piston hammer structure;

[0038] Figure 7 It is a schematic diagram of the structure of the live valve;

[0039] Figure 8 is a schematic diagram of the anvil structure;

[0040] Fig. 9 for Figure 1 AA section diagram in;

[0041] Fig.10 for Figure 1 Schematic diagram of the state after the middle live valve moves upward;

[0042] Fig.11 for Fig.10 Schematic diagram of the piston hammer moving upward.

[0043] In the figure:

[0044] 1. Upper joint, 2. Sealing ring, 3. Upper cylinder sleeve, 4. Guide sleeve, 5. Limit pad, 6. Live valve, 7. Piston hammer guide sleeve, 8. Piston hammer, 9. Shell tube, 10. Anvil, 11. Guide bushing, 12. Limit section, 13. Stop ring, 14. Spline section, 15. Sleeve, 16. Closed cylindrical section, 17. Impact drill bit, 18. Water inlet, 19 Ring groove, 20. Shoulder, 21. Sand discharge groove, 22. Annular cavity, 23. Lateral drainage hole, 24 Piston hammer center water hole, 25. Center liquid flow channel, 26. Outer drainage annulus, 27. Lateral throttling hole, 28. Inward-shrinking cylindrical section, 29. Lifting hammer groove, 30. Outer drainage hole, 31. Leakage hole, 32. Drill center water hole. DETAILED DESCRIPTION

[0045] The present invention is further described below in conjunction with the embodiments. It should be noted that, in this article, words such as "upper", "lower", etc. are only used to facilitate the description of the drawings, and do not limit the direction in actual use, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprises", or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device that includes a series of elements includes not only those elements, but also includes other elements that are not explicitly listed, or also includes elements inherent to such process, method, article, or device.

[0046] like Figure 1-11As shown, a valve-type double-acting hydraulic impactor capable of improving working performance comprises a connecting section, a telescopic section, an impact section, and an external shell; the connecting section is an upper joint 1, which is used to connect with an upper drill pipe; a telescopic section is provided below the upper joint 1, and the telescopic section comprises an upper cylinder sleeve 3, a limit pad 5, a live valve 6, and a piston hammer 8; the impact section comprises an anvil 10 and a drill bit assembly, and the external shell comprises an outer shell tube 9; the live valve 6 is used to interact with a high-pressure driving liquid, and reciprocate relative to the outer shell tube 9, so as to drive the piston hammer 8 to periodically strike the anvil 10, and the impact work received by the anvil 10 is transmitted to the drill bit assembly connected thereto, so as to impact and break the rock; flow channels are provided in the connecting section, the telescopic section, and the impact section, so that the liquid flows from top to bottom, and the telescopic section is driven to move by the liquid to realize power transmission to the impact section. The middle parts of the upper joint 1, the upper cylinder sleeve 3, the limit pad 5, the live valve 6, and the piston hammer 8 are all hollow structures, forming a flow channel from top to bottom as a central waterway, and realizing reciprocating motion by opening and closing the central waterway, and impacting and breaking rocks in the process; the live valve 6 and the piston hammer 8 form a valve structure, the live valve 6 is a hollow cylinder, the lower half of the hollow cylinder is a convex cone extending inward for a short section, and the cone angle is 120°; the outer wall of the live valve 6 includes three sections, the upper, middle and lower sections, the upper section of the live valve 6 is a dumbbell-shaped outer wall with protruding ends and contracted in the middle, and the outer diameter of the lower shoulder 20 of the upper section is larger than the outer diameter of the upper edge, and the upper and lower ends are stuck in the limit pad 5, and the limit pad 5 Used to limit the upper and lower displacement limit positions of the live valve 6; the annular groove 19 on the inner side of the upper part of the live valve 6 is processed with a chamfer of 25°, so that the upper end of the live valve will not be unable to move up due to high pressure, and the aggregation of the driving liquid is also guaranteed. The live valve 6 can move freely up and down in the limit pad 5; the up and down movement of the live valve 6 is limited by the shoulder 20 and the limit pad 5. The shoulder 20 protrudes outward by 10mm and has a chamfer of 5mm; the outer diameter of the middle section of the live valve 6 is larger than that of the lower section, and a flow channel with a side opening is provided at the bottom of the lower section; the middle section of the live valve 6 is a smooth cylindrical surface, the radial runout of the major diameter is 0.01~0.03mm, and the surface roughness Ra value is 0.63~0.16 , the bottom of the live valve 6 is chamfered by 5mm; the upper part of the live valve 6 is sleeved in the inner flow channel of the upper cylinder sleeve 3; the piston hammer 8 is a hollow cylinder penetrating from top to bottom, and the inner wall of the piston hammer 8 includes three sections, upper, middle and lower. The inner wall of the upper section of the piston hammer 8 is provided with three steps from top to bottom, the inner diameter of the first section is smaller than the inner diameter of the second section, the inner diameter of the second section is larger than the inner diameter of the third section, forming an annular cavity 22, the third section is used as the central water hole 24 of the piston hammer, and the inner diameter of the first section is the same as the outer diameter of the middle section of the live valve 6. The inner diameter of the third section matches the outer diameter of the lower section of the live valve 6; the force-bearing surface at the lower end of the live valve 6 is a horizontal circular surface, and the force-bearing surface at the upper end is a conical surface; the inner wall of the middle section of the piston hammer 8 is a straight pipe section as the central liquid flow channel 25; the lower section of the piston hammer 8 is a shrinking cylindrical section 28 and a horizontal step is provided between the central liquid flow channel 25, and the inner diameter of the shrinking cylindrical section 28 is larger than the central liquid flow channel 25, and the inner wall of the shrinking cylindrical section 28 is sleeved on the outer side of the anvil 10 and maintained at 2mm The clearance fit of the piston hammer 8 is such that repeated impacts will not deviate from the center position of the anvil 10; the upper side of the outer wall of the piston hammer 8 is provided with three layers whose diameters increase from top to bottom, and a guide sleeve 4 is provided on the outer side of the upper cylinder sleeve 3, and a piston hammer guide sleeve 7 is provided below the guide sleeve 4, and the piston hammer guide sleeve 7 matches the outer diameter of the second layer on the upper side of the outer wall of the piston hammer 8; the side of the central liquid flow channel 25 is provided with at least two lateral throttling holes 27 penetrating the wall of the piston hammer 8, and the diameter of the lateral throttling holes 27 is much smaller than the inner diameter of the central liquid flow channel 25; there is an annulus between the piston hammer 8 and the outer shell tube 9, which serves as an outer drainage annulus 26, and the outer cylindrical surface of the piston hammer 8 where the lateral throttling holes 27 are located is a closed cylindrical section 16 that shrinks inward by 10 mm, so as to reduce the impact force of the liquid ejected from the lateral throttling holes 27 on the outer shell tube 9 and reduce the damage to the outer shell tube 9. The shrinkage distance of 10 mm is selected to consider the maximum shrinkage value when the strength meets the requirements. The clearance between the upper part of the piston hammer 8 and the middle part of the live valve 6 is matched, and the high-pressure liquid flow will not spray out from the clearance between the upper part of the piston hammer 8 and the middle part of the live valve 6; the lower end surface of the live valve 6 is flush with the upper end surface of the central water hole 24 of the piston hammer and there is a diameter difference of 2mm. When the liquid pressure is high, the upper part of the annular cavity 22 is a 45° inclined surface, and the area of ​​the upper inclined surface is larger than the area of ​​the lower horizontal surface, forming an annular area difference. The downward pressure of the driving liquid is much greater than the upward pressure. The piston hammer 8 at the lower limit position cannot move downward, so that the small-mass live valve 6 quickly moves to the upper limit position, and the central water channel is opened. The piston hammer 8 starts to move upward until the bottom of the live valve 6 is just inserted into the central water hole 24 of the piston hammer. The central water channel is closed and water hammer pressure is generated. The water hammer pressure acts on the annular area again. Since the downward annular pressure difference generated by the driving liquid in the annular cavity is extremely large, the piston hammer 8 can be pushed downward quickly. Since the horizontal annular force area is relatively small, the piston hammer 8 has a higher downward speed during the stroke movement, thereby obtaining a higher anvil end speed, which is beneficial to increase the impact work of the hydraulic impactor and improve the working performance.

[0047] The upper end of the drill bit assembly is connected to the bottom of the anvil 10, and a drill bit upper limit section 12 is provided on the upper part of the outer diameter surface of the drill bit assembly to ensure that the drill bit assembly will not fall out of the outer shell tube 9 when moving up and down. A spline section 14 is provided in the middle of the drill bit assembly, and an internal spline matching the spline section 14 is provided on the inner side of the outer shell tube 9 to ensure that the drill bit can move up and down along the internal spline so that the drill bit assembly does not rotate. An impact drill bit 17 is provided below the spline section 14. The impact drill bit 17 is located on the lower side of the outer shell tube 9, and the outer diameter of the impact drill bit 17 is larger than the spline section 14. The limit displacement of the drill bit assembly moving upward is maintained by the step between the impact drill bit 17 and the spline section 14.

[0048] The inner wall of the outer shell tube 9 corresponding to the drill assembly is provided with a guide bushing 11, a stop ring 13, and a sleeve 15 from top to bottom. The sleeve 15 is provided with an internal spline. The stop ring 13 cooperates with the drill upper limit section 12 to limit the downward displacement of the drill assembly. The outer side of the sleeve 15 is provided with an external thread, and the bottom of the outer shell tube 9 is provided with an internal thread. The sleeve 15 is fixed to the bottom of the outer shell tube 9 by screwing. A step is provided inside the lower side of the outer shell tube 9. When the sleeve 15 is installed in place, the guide bushing 11 is pressed against the step on the lower side of the outer shell tube 9.

[0049] The bottom of the movable valve 6 is a closed structure, and the flow channel with a side opening above the bottom of the movable valve 6 is used as a lateral drainage hole 23. The bottom of the annular cavity 22 corresponding to the lateral drainage hole 23 is kept close to the bottom of the movable valve 6 in the initial state, and the bottom of the movable valve 6 is provided with a chamfer, and the upper edge of the central water hole 24 of the piston hammer is also provided with a chamfer, so that a gap is maintained between the bottom of the movable valve 6 and the central water hole 24 of the piston hammer in the initial state.

[0050] The anvil 10 includes an upper section whose inner diameter matches the inward-retracted cylindrical section 28 and a lower section whose inner diameter is larger than that of the inward-retracted cylindrical section 28, and the upper section of the anvil 10 contacts the horizontal step of the inward-retracted cylindrical section 28, and the step between the lower section of the anvil 10 and the upper section of the anvil 10 contacts the bottom of the piston hammer 8; when the piston hammer 8 abuts against the anvil 10, there are multiple grooves between the horizontal section step of the inward-retracted cylindrical section 28 and the top of the anvil 10, which serve as hammer lifting grooves 29; the lower section of the anvil 10 is provided with a countersunk hole upward, and the step between the lower section of the anvil 10 and the upper section of the anvil 10 is provided with multiple outer drainage holes 30 connected to the countersunk hole, and multiple drainage holes 31 are provided on the piston hammer 8 corresponding to the outer drainage holes 30; a drill bit center water hole 32 is provided in the drill bit assembly to receive the liquid sent from the outer drainage hole 30 and discharge it from the impact drill bit 17. All parts of the drill assembly are easy to assemble, with low requirements for axial tolerance, the increased tolerance is absorbed by the axial elastic compression, and all parts can slide easily in the impactor housing tube 9, so it is easy to disassemble when disassembling.

[0051] The piston hammer guide sleeve 7 is used to gather the piston hammer 8 to the position of the axis when it moves up. The lower end of the piston hammer guide sleeve 7 is a sand discharge groove 21. The upper part of the piston hammer 8 and the bottom of the piston hammer guide sleeve 7 are close to a transition circle chamfer of 10 mm. The inner diameter is 5 mm larger than the upper end of the piston hammer, ensuring that the piston hammer 8 can be accurately inserted into the piston hammer guide sleeve 7 without direct contact. The lower end of the piston hammer guide sleeve 7 is a sand discharge groove 21, which can guide the mud and sand entering the cavity between the upper part of the piston hammer 8 and the upper cylinder sleeve 3 into the outer drainage hole 30.

[0052] The upper joint 1 is connected to the upper inner side of the outer shell tube 9 through a threaded section arranged on the lower side, and a sealing ring 2 is arranged between the upper joint 1 and the outer shell tube 9; the upper cylinder sleeve 3 is arranged in the guide sleeve 4, and the upper cylinder sleeve 3 is shorter than the guide sleeve 4, and the bottom of the guide sleeve 4 is provided with an inwardly contracted step, and a limiting pad 5 is fixed between the upper cylinder sleeve 3 and the guide sleeve 4 through the step. The limiting pad 5 is an annular structure with an opening on one side, and the width of the open side is the same as the minimum outer diameter of the upper section of the active valve 6. After the limiting pad 5 is inserted into the active valve 6, the active valve 6 is used to limit the up and down movement.

[0053] The above scheme is adopted to simulate the gas well drilling in the southern part of Sichuan Basin, with a depth of 2400m. The main rock is brown dense blocky quartz feldspar mud siltstone. Therefore, after core sampling and analysis, the local starting value pressure P1 is set to 18MPa, P max The pressure is 20 MPa, and a computer simulation is performed. A valve-type double-acting hydraulic impact method without rigid collision is implemented, comprising the following steps:

[0054] S1. In the initial state, the piston hammer 8 and the valve 6 are both at the lowest position under the action of gravity;

[0055] S2, the pressure of the liquid input from the top includes the starting value P1 and the upper limit value P max ; When the pressure is greater than the upper limit value P max When the high-pressure liquid sent from the wellhead is sent into the hydraulic impactor through the water inlet 18 of the central drill pipe column upward joint 1, it first enters the inner cavity of the live valve 6, and flows into the annular cavity 22 formed by the live valve 6 and the piston hammer 8 from the lateral drainage hole 23 at the bottom of the inner cavity. Since the live valve 6 is at the lowest position at this time, the gap between it and the piston hammer 8 is too small to allow a large amount of liquid to enter the central water hole 24 of the piston hammer. The pressure in the annular cavity 22 increases rapidly, forcing the lighter live valve 6 to move upward rapidly until the shoulder 20 of the live valve is blocked by the limit pad 5;

[0056] After the live valve 6 rises, since the flow channel from the annular cavity 22 to the central water hole 24 of the piston hammer is opened, the high-pressure liquid enters the lower end of the central liquid flow channel 25 of the piston hammer 8, and the high-pressure liquid flows out through the lateral throttling hole 27. However, due to the small size of the lateral throttling hole 27, it is impossible to discharge all the liquid in the central liquid flow channel 25 in time. At this time, a large amount of liquid is pressed in the central liquid flow channel 25 and acts on the lower surface of the live valve 6 again to lift it. Since the pressure on the upper surface area of ​​the live valve 6 and its own gravity are less than the pressure on the lower surface, and the live valve 6 is light in weight, the live valve 6 continues to maintain at the upward displacement limit and quickly moves a distance of h to the upper limit of the live valve.

[0057] When drilling a vertical well normally, the drill string has several drill rods with an outer diameter of 127.0 mm, an inner diameter of 112.0 mm, a drilling pressure of 0-200 kN, a cam stroke of 10 mm, and an elastic modulus of the drill string steel of 206 GPa.

[0058] S3, after the pressure in the central liquid flow channel 25 is suppressed, the lifting hammer groove 29 is pressurized, and the entire piston hammer 8 is lifted upward, until the piston hammer 8 rises to the central water hole 24 of the piston hammer and moves to the bottom of the live valve 6 and plugs into each other. At this time, the passage from the annular cavity 22 to the central water hole 24 of the piston hammer is blocked, and the upward movement speed of the piston hammer 8 decreases but does not stop. At this time, the upper part of the live valve 6 is much more pressurized than the lower part after the passage is blocked, resulting in a water hammer effect, and the live valve 6 quickly moves down to the lowest position. At the same time, the lower half of the live valve 6 is inserted into the central water hole 24 of the piston hammer, and the piston hammer 8 stops moving from upward and moves downward;

[0059] When the piston hammer 8 moves upward to the limit, the inwardly contracted cylindrical section 28 and the anvil are connected to the outer drainage annulus 26 through the outer drainage hole 30, and the high-pressure liquid in the central liquid flow channel 25 flows out from the lateral throttle hole 27 and the outer drainage hole 30, and enters the central water hole 32 of the drill bit through the leakage hole 31, and is sprayed out from the spray hole of the impact drill bit 17 to assist in rock breaking and chip removal;

[0060] When the thrust distance is 10 mm and the actual drilling pressure is 40-60 kN, the impact energy of the drilling tool required for rock breaking in medium-hard formations is 300-450 J.

[0061] S4. As the space of the annular cavity 22 decreases and the pressure increases, the piston hammer 8 accelerates downward under pressure and quickly moves to the lowest point to hit the upper surface of the anvil 10. The anvil 10 evenly transfers the impact force to the drill bit assembly and impacts the rock through the impact drill bit 17. Under the restriction of the spline segment 14, the drill bit assembly only moves axially and does not rotate circumferentially.

[0062] During the test, the entire tool was first lifted about 100mm from the bottom of the well, and the pump was turned on to increase the displacement to 30L / s. After the operation was stable, the drill bit was lowered and the drilling pressure was increased to 40kN. The drilling speed, impact frequency, pump pressure, impact work, power consumption and other parameters were recorded.

[0063] S5, after the piston hammer 8 hits the anvil 10, the active valve 6 is limited and braked by the limit pad 5, and the piston hammer 8 moves to the lowest position and is restored to the initial position of the initial state by the reverse thrust of the rock. The active valve 6 and the piston hammer 8 are both at the lowest position, and the situation in S2 occurs again. The active valve 6 rises again and waits for the piston hammer 8 to rise again, and then the water hammer effect is generated again to make the piston hammer 8 impact the anvil 10, realizing the hydraulic impact;

[0064] Reduce the drilling pressure to 35kN, 30kN, 25kN, 20kN, 15kN, 10kN, and 5kN in sequence, record the above parameters, increase the displacement to 40L / s, and repeat the test.

[0065] S6. Through the above steps, the drilling speed of the device provided by the present invention in the core test is 8.61m / h; the impact function reaches 400~600J. Compared with the existing hydraulic impactor, the drilling efficiency is increased by 25% and the failure rate is reduced by 20%.

[0066] The above scheme has a simple structure and low processing requirements, which reduces costs and also increases the service life of parts, improves the utilization rate of water energy, and improves the working performance of the hydraulic impactor.

[0067] In step S2, when the pressure is less than the limit value and greater than the start value P1, after starting, the live valve 6 will not quickly reach the upper limit position, but will stop at a certain stage in the upward movement process under the action of its own weight, overcoming the downward impact force received by the convex cone, and the upward pressure of the annular cavity 22, and will not reach the upper limit position; at the same time, the displacement limit of the piston hammer 8 will also change accordingly, and will not reach the upward displacement limit described in step S2, that is, it will turn to downward movement. This situation will not affect normal rock breaking, but will reduce the impact work of rock breaking. The adaptability of downhole impact drilling tools operated from the wellhead is greatly improved, and it can be used in environments with rock breaking requirements in various formations.

[0068] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. Any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A valve-type double-acting hydraulic impactor capable of improving working performance, characterized in that: The invention comprises a connecting section, a telescopic section, an impact section and an external shell; the connecting section is an upper joint (1) for connecting to an upper drill pipe; a telescopic section is provided below the upper joint (1), the telescopic section comprises an upper cylinder sleeve (3), a limit pad (5), a live valve (6) and a piston hammer (8); the impact section comprises an anvil (10) and a drill bit assembly, and the external shell comprises an outer shell tube (9); the live valve (6) is used to interact with a high-pressure driving liquid and reciprocate relative to the outer shell tube (9) to drive the piston hammer (8) to periodically strike the anvil (10), and the impact work received by the anvil (10) is transmitted to the drill bit assembly connected thereto to perform impact rock breaking; flow channels are provided in the connecting section, the telescopic section and the impact section to allow liquid to flow from top to bottom, and the telescopic section is driven by the liquid to move so as to transmit power to the impact section; The middle parts of the upper joint (1), the upper cylinder sleeve (3), the limit pad (5), the live valve (6), and the piston hammer (8) are all hollow structures, forming a flow channel from top to bottom as a central waterway, and realizing reciprocating motion by opening and closing the central waterway, and impacting and breaking rocks in the process; The live valve (6) is a hollow cylinder, the lower half of which is a convex cone extending inward for a short distance, with a cone angle of 120°. The outer wall of the live valve (6) includes three sections: an upper section, a middle section and a lower section. The outer wall of the upper section of the live valve (6) is a dumbbell-shaped section with protruding ends and contracted in the middle. The outer diameter of the lower shoulder (20) of the upper section is larger than the outer diameter of the upper edge. The upper and lower ends are clamped in the limit pad (5), and the limit pad (5) is used to limit the upper and lower displacement limit positions of the live valve (6). The outer diameter of the middle section of the live valve (6) is larger than that of the lower section, and a flow channel with a side opening is provided at the bottom of the lower section. The upper part of the live valve (6) is sleeved in the inner flow channel of the upper cylinder sleeve (3). The piston hammer (8) is a hollow cylinder penetrating from top to bottom. The inner wall of the piston hammer (8) includes three sections: upper, middle and lower. The inner wall of the upper section of the piston hammer (8) is provided with three steps from top to bottom. The inner diameter of the first section is smaller than the inner diameter of the second section, and the inner diameter of the second section is larger than the inner diameter of the third section, forming an annular cavity (22). The third section serves as the central water hole (24) of the piston hammer. The inner diameter of the first section matches the outer diameter of the middle section of the live valve (6), and the inner diameter of the third section matches the outer diameter of the lower section of the live valve (6). The inner wall of the middle section of the piston hammer (8) is a straight pipe section serving as the central liquid flow channel (25). The upper part of the annular cavity (22) is a 45° inclined surface. The area of ​​the upper inclined surface is larger than the area of ​​the lower horizontal surface, forming an annular area difference. The lower section of the piston hammer (8) is provided with a horizontal step between the indented cylindrical section (28) and the central liquid flow channel (25). The inner diameter of the indented cylindrical section (28) is larger than the inner diameter of the central liquid flow channel (25). The inner wall of the inwardly contracted cylindrical section (28) is sleeved on the outer side of the anvil (10) and maintains a clearance fit of 2 mm; the upper side of the outer wall of the piston hammer (8) is provided with three layers whose diameters increase from top to bottom, and a guide sleeve (4) is provided on the outer side of the upper cylinder sleeve (3), and a piston hammer guide sleeve (7) is provided below the guide sleeve (4), and the piston hammer guide sleeve (7) matches the outer diameter of the second layer on the upper side of the outer wall of the piston hammer (8); the side of the central liquid flow channel (25) is provided with at least two lateral throttling holes (27) penetrating the wall of the piston hammer (8), and the diameter of the lateral throttling holes (27) is much smaller than the inner diameter of the central liquid flow channel (25); there is an annulus between the piston hammer (8) and the outer shell tube (9), which serves as an outer drainage annulus (26); the lower end surface of the active valve (6) is flush with the upper end surface of the central water hole (24) of the piston hammer and has a diameter difference of 2 mm; The anvil (10) comprises an upper section whose inner diameter matches the inward-retracted cylindrical section (28) and a lower section whose inner diameter is larger than the inward-retracted cylindrical section (28), and the upper section of the anvil (10) contacts the horizontal step of the inward-retracted cylindrical section (28), and the step between the lower section of the anvil (10) and the upper section of the anvil (10) contacts the bottom of the piston hammer (8), and when the piston hammer (8) and the anvil (10) are in contact, a plurality of grooves are provided between the horizontal step of the inward-retracted cylindrical section (28) and the top of the anvil (10), serving as hammer lifting grooves (29); The lower section of the anvil (10) is provided with a countersunk hole upwardly, a step between the lower section of the anvil (10) and the upper section of the anvil (10) is provided with a plurality of outer drainage holes (30) connected to the countersunk hole, and a plurality of drainage holes (31) are provided on the piston hammer (8) corresponding to the outer drainage holes (30); A drill bit center water hole (32) is provided in the drill bit assembly to receive liquid sent from the outer drainage hole (30) and discharge it from the impact drill bit (17).

2. A valve-type double-acting hydraulic impactor capable of improving working performance according to claim 1, characterized in that: The upper end of the drill assembly is connected to the lower part of the anvil (10); an upper drill limit section (12) is provided on the upper part of the outer diameter surface of the drill assembly to ensure that the drill assembly will not fall out of the outer shell tube (9) when the drill assembly moves up and down; a spline section (14) is provided in the middle of the drill assembly; an internal spline matching the spline section (14) is provided on the inner side of the outer shell tube (9) to ensure that the drill can move up and down along the internal spline so that the drill assembly does not rotate; an impact drill bit (17) is provided below the spline section (14); the impact drill bit (17) is located on the lower side of the outer shell tube (9); the outer diameter of the impact drill bit (17) is larger than the spline section (14); and the limit displacement of the upward movement of the drill assembly is maintained by the step between the impact drill bit (17) and the spline section (14).

3. A valve-type double-acting hydraulic impactor capable of improving working performance according to claim 2, characterized in that: The inner wall of the shell tube (9) corresponding to the drill assembly is provided with a guide bushing (11), a stop ring (13), and a sleeve (15) in order from top to bottom. The sleeve (15) is provided with an internal spline. The stop ring (13) cooperates with the drill upper limit section (12) to limit the downward displacement of the drill assembly. The outer side of the sleeve (15) is provided with an external thread. The bottom of the shell tube (9) is provided with an internal thread. The sleeve (15) is fixed to the bottom of the shell tube (9) by screw connection. A step is provided inside the lower side of the shell tube (9). When the sleeve (15) is installed in place, the guide bushing (11) is pressed against the step on the lower side of the shell tube (9).

4. A valve-type double-acting hydraulic impactor capable of improving working performance according to claim 3, characterized in that: The bottom of the live valve (6) is a closed structure, and a flow channel with a side opening above the bottom of the live valve (6) is used as a lateral drainage hole (23). The bottom of the annular cavity (22) corresponding to the lateral drainage hole (23) is kept close to the bottom of the live valve (6) in an initial state, and the bottom of the live valve (6) is provided with a chamfer, and the upper edge of the central water hole (24) of the piston hammer is also provided with a chamfer, so that a gap is maintained between the bottom of the live valve (6) and the central water hole (24) of the piston hammer in an initial state.

5. A valve-type double-acting hydraulic impactor capable of improving working performance according to claim 4, characterized in that: The upper joint (1) is connected to the inner side of the upper part of the outer shell tube (9) via a threaded section provided on the lower side, and a sealing ring (2) is provided between the upper joint (1) and the outer shell tube (9); the upper cylinder sleeve (3) is sleeved in the guide sleeve (4), and the upper cylinder sleeve (3) is shorter than the guide sleeve (4); a step contracting inward is provided at the bottom of the guide sleeve (4); a limiting pad (5) is fixed between the upper cylinder sleeve (3) and the guide sleeve (4) via the step; the limiting pad (5) is an annular structure with one side open, and the width of the open side is the same as the minimum outer diameter of the upper section of the live valve (6); after the limiting pad (5) is inserted into the live valve (6), the live valve (6) realizes the limiting of the up and down movement.

6. A valve-type double-acting hydraulic impact method capable of improving working performance, characterized in that: The valve-type double-acting hydraulic impactor with improved working performance as claimed in claim 5 comprises the following steps: S1. In the initial state, the piston hammer (8) and the valve (6) are both at the lowest position under the action of gravity; S2. The pressure of the liquid input from the top includes a starting value and an upper limit value. When the pressure is greater than the upper limit value, the high-pressure liquid sent from the wellhead is sent into the hydraulic impactor through the water inlet (18) of the central drill pipe column upward joint (1), and first enters the inner cavity of the live valve (6), and flows into the annular cavity (22) formed by the live valve (6) and the piston hammer (8) from the lateral drainage hole (23) at the bottom of the inner cavity. Since the live valve (6) is at the lowest position at this time, the gap between the live valve (6) and the piston hammer (8) is too small to allow a large amount of liquid to enter the central water hole (24) of the piston hammer. The pressure in the annular cavity (22) increases rapidly, forcing the lighter live valve (6) to move upward rapidly until the shoulder (20) of the live valve is blocked by the limit pad (5); After the live valve (6) rises, the flow passage from the annular cavity (22) to the central water hole (24) of the piston hammer opens, and the high-pressure liquid enters the lower end of the central liquid flow channel (25) of the piston hammer (8). The high-pressure liquid flows out through the lateral throttling hole (27). However, due to the small size of the lateral throttling hole (27), it is impossible to discharge all the liquid in the central liquid flow channel (25) in time. At this time, a large amount of liquid is pressed in the central liquid flow channel (25) and acts on the lower surface of the live valve (6) again to lift it. Since the pressure on the upper surface area of ​​the live valve (6) and its own gravity are smaller than the pressure on the lower surface, the live valve (6) continues to maintain the upward displacement limit; S3, after the pressure in the central liquid flow channel (25) is suppressed, the lifting hammer groove (29) is pressurized, and the entire piston hammer (8) is lifted upward until the piston hammer (8) rises to the piston hammer central water hole (24) and moves to the bottom of the live valve (6) and plugs into each other. At this time, the passage from the annular cavity (22) to the piston hammer central water hole (24) is blocked, and the upward movement speed of the piston hammer (8) decreases but does not stop. At this time, after the passage is blocked, the upper part of the live valve (6) is much more pressurized than the lower part, resulting in a water hammer effect. The live valve (6) quickly moves down to the lowest position, and at the same time, the lower half of the live valve (6) is inserted into the piston hammer central water hole (24), and the piston hammer (8) stops moving upward and moves downward; When the piston hammer (8) moves upward to the limit, the inwardly contracted cylindrical section (28) and the anvil are connected to the outer drainage annulus (26) through the outer drainage hole (30), and the high-pressure liquid in the central liquid flow channel (25) flows out from the lateral throttle hole (27) and the outer drainage hole (30), and enters the central water hole (32) of the drill bit through the leakage hole (31), and is sprayed out from the spray hole of the impact drill bit (17) to assist in rock breaking and chip removal; S4. As the space of the annular cavity (22) decreases and the pressure increases, the piston hammer (8) accelerates downward under pressure and quickly moves to the lowest point to hit the upper surface of the anvil (10). The anvil (10) evenly transfers the impact force to the drill bit assembly and impacts the drill bit (17) to break the rock. Under the restriction of the spline section (14), the drill bit assembly only moves axially and does not rotate circumferentially. S5, after the piston hammer (8) hits the anvil (10), the live valve (6) is limited and braked by the limit pad (5), and the piston hammer (8) moves to the lowest point and is restored to the initial position of the initial state by the reverse thrust of the rock. The live valve (6) and the piston hammer (8) are both at the lowest point, and the situation in S2 occurs again. The live valve (6) rises again and waits for the piston hammer (8) to rise again, and then the water hammer effect is generated again to make the piston hammer (8) hit the anvil (10), thereby realizing hydraulic impact.

7. A valve-type double-acting hydraulic impact method capable of improving working performance as claimed in claim 6, characterized in that: In step S2, when the pressure is less than the limit value and greater than the start value, after starting, the active valve (6) will not quickly reach the upper limit position, but will stop at a certain point in the upward movement process under the action of its own weight, the downward impact force on the convex cone, and the upward pressure of the annular cavity (22), and will not reach the upper limit position; at the same time, the displacement limit of the piston hammer (8) will also change accordingly, and will not reach the upward displacement limit described in step S2, that is, turn to downward movement. This situation will not affect normal rock breaking, but will reduce the impact work of rock breaking.

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