Valve type axial impact tool

Abstract

The application provides a valve type axial impact tool, relates to the technical field of oil and gas exploitation, and aims to solve the technical problem of low working efficiency of the valve type axial impact tool. The valve type axial impact tool comprises a plurality of cavities formed by a characteristic structure inside the valve type axial impact tool, and a pressure difference is formed by drilling fluid introduced into the cavities. The pressure difference enables the components inside the valve type axial impact tool to move axially in coordination to achieve different movement and working states, thereby realizing linear reciprocating movement of a hammer inside the valve type axial impact tool and generating periodic impact load through periodic impact contact with a second joint. The periodic impact load is further transmitted to a drill bit, thereby significantly improving the working efficiency of the drill bit. The valve type axial impact tool provided by the application is used for assisting rock breaking work in deep well oil and gas exploitation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil and gas exploitation, and particularly relates to a valve type axial impact tool. BACKGROUND

[0002] Exploration and development of oil and gas resources has been continuously developed as a key part of resource excavation, and the depth of exploration and development of oil and gas resources has gradually shifted from shallow strata to deep strata. The exploration and development of oil and gas resources in deep strata is mainly carried out by establishing deep or ultra-deep wells from the ground to the underground. In the drilling operation of deep or ultra-deep wells, as the drilling depth increases, the abrasiveness of the drilled rock gradually increases, that is, the strength and hardness of the drilled rock increase, and the wear resistance also increases, which increases the difficulty of drilling operation and easily causes the damage and instability of the drilling tool components and the combination drilling string. The combination drilling string mainly refers to the connection and cooperation of drilling tools including a drill bit and a drill string. The drill string includes a drill rod, a drill collar, a joint and a centralizer. The rock of the deeper hard stratum, i.e. the abrasive stratum, will reduce the rock breaking efficiency of the drill bit, resulting in a decrease in the mechanical drilling speed of the drill tool and a decrease in the operation efficiency.

[0003] In addition, the abrasive stratum is also prone to stick-slip vibration of the drill bit. The stick-slip vibration refers to a damaged form of the drill bit under high pressure. When the drill bit drills the rock of the abrasive stratum, the drill bit will be subjected to periodic load given by the rock of the abrasive stratum. Under the action of the periodic load, stress concentration will occur in the drill bit, and then cracks will occur on the surface and inside the drill bit. The process of crack generation will cause relative sliding between the bonded materials and the broken materials or between the broken materials and the matrix. The above-mentioned material bonding and material sliding phenomenon alternately occur on the drill bit during the drilling process. The fracture surface will periodically jump and slide. Under the action of the periodic stress, the accumulated strain energy will be gradually released, thereby embodying the stick-slip phenomenon.

[0004] In this way, the wear of the drill bit is accelerated, and even the fracture of the drill bit cutting teeth occurs. The failure and instability of the drill bit will also cause the instability of the drill string connected and cooperated with the drill bit. In this way, the service life of the drill bit and the drill string is reduced, and the drilling cost is significantly increased.

[0005] At present, the axial impact drilling technology is used to solve the problem of low mechanical drilling speed in the process of deep well drilling. The axial impact drilling technology mainly generates an axial impact load on the drill bit through an axial impact tool to increase the cutting depth of the cutting teeth and thereby improve the rock breaking efficiency of the drill bit. However, the existing valve type axial impact tool has low working efficiency. SUMMARY

[0006] In view of the low efficiency of the valve type axial impact tool in the deep well drilling process, and the low rock breaking efficiency of the drill bit, based on the axial impact drilling technology, a valve type axial impact tool is provided, a plurality of cavities are formed through the internal structure design of the drilling tool, the hydraulic pressure difference generated in the plurality of cavities by the drilling fluid is used to drive the hammer to generate periodic axial impact load on the drill bit, so as to increase the cutting depth of the cutting teeth, and the working efficiency of the valve type axial impact tool is improved to improve the rock breaking efficiency of the drill bit.

[0007] In order to achieve the above-mentioned purpose, the present application provides the following technical scheme:

[0008] The valve type axial impact tool comprises a shell, a drilling tool joint and a flow guide cylinder, a control valve assembly and a hammer arranged in the shell, and the hammer is in sliding fit with the shell.

[0009] The flow guide cylinder, the control valve assembly and the hammer have flow guide holes in sequence, and the outer peripheral surface of the hammer is sleeved with a pressure bearing ring.

[0010] The drilling tool joint comprises a first joint and a second joint, the first joint is mounted at the first end of the shell, and the first joint abuts against the flow guide cylinder; the second joint is mounted at the second end of the shell, and the second joint is configured to abut against the hammer when the hammer is at the first position.

[0011] The side of the first joint facing the pressure bearing ring, the side of the pressure bearing ring facing the first joint, the outer peripheral surface of the flow guide cylinder, the outer peripheral surface of the control valve assembly and the inner surface of the shell form a first cavity; the inner surface of the shell is provided with a first boss, the first boss is located between the pressure bearing ring and the second joint, the side of the pressure bearing ring away from the first joint, the inner surface of the shell, the side of the first boss facing the first joint and the outer peripheral surface of the hammer form a second cavity; the side of the first boss away from the first joint, the inner surface of the shell and the outer peripheral surface of the hammer form a third cavity.

[0012] The side wall of the shell is provided with a first through hole to communicate the third cavity with the outside of the shell.

[0013] The first cavity, the second cavity and the third cavity are configured to form a first pressure difference between the first cavity and the second cavity when the drilling fluid flows into the shell, and a second pressure difference between the third cavity and the inside of the hammer, when the first pressure difference is greater than the second pressure difference, the drilling fluid pushes the hammer to slide relative to the shell to impact the second joint to transmit load to the drill bit.

[0014] The present application has at least the following advantages:

[0015] The valve type axial impact tool provided by the application takes high-pressure drilling fluid as a driving medium, and realizes valve type control of reciprocating movement of a hammer through a control valve assembly arranged inside, so that stable periodic axial impact load can be generated on a second joint, and then transmitted to a drill bit and the rock breaking energy of the drill bit is increased. On the basis of rotary rock breaking, the cutting tooth penetration depth of the drill bit is increased, and the rock breaking efficiency and the rate of penetration are effectively improved. Moreover, the valve type axial impact tool has fewer moving parts, is stable and reliable, has a short overall structure, and has a wide application range.

[0016] In the valve type axial impact tool, optionally, the flow guide hole includes a plurality of first flow guide holes which are circumferentially spaced apart on the side wall of the flow guide cylinder and are used for guiding fluid from the first joint.

[0017] In the valve type axial impact tool, optionally, a flow guide part is arranged in the flow guide cylinder, and the inside of the flow guide cylinder is divided into two cavities in the axial direction by the flow guide part. The cavity close to the first joint is a flow guide cavity which is used for guiding fluid from the first joint into the first cavity. The cavity away from the first joint is a sliding cavity, and the control valve assembly is located in the sliding cavity and can slide relative to the flow guide cylinder.

[0018] In the valve type axial impact tool, optionally, the flow guide part is a conical flow guide part, and a first conical surface of the conical flow guide part faces the first joint.

[0019] In the valve type axial impact tool, optionally, the control valve assembly includes a control valve core, a control valve outer cylinder which is sleeved on the control valve core, and a control valve end cover which covers the end of the control valve outer cylinder. The control valve outer cylinder is slidingly connected to the flow guide cylinder, and the control valve outer cylinder abuts against the pressure bearing ring.

[0020] In the valve type axial impact tool, optionally, the flow guide hole includes a second flow guide hole, a third flow guide hole and a fourth flow guide hole. A plurality of the second flow guide holes are circumferentially spaced apart on the cylinder wall of the control valve outer cylinder.

[0021] A second boss is arranged on the side wall of the control valve core and abuts against the control valve outer cylinder. A plurality of the third flow guide holes are circumferentially spaced apart on the side wall of the second boss, and each of the third flow guide holes in the plurality of the third flow guide holes is in communication with each of the second flow guide holes, so that the inside of the control valve assembly is in communication with the first cavity.

[0022] The fourth flow guide hole is arranged on the side wall of the hammer, so that the inside of the hammer is in communication with the second cavity.

[0023] In the valve type axial impact tool, optionally, the valve type axial impact tool further comprises an adjusting plug arranged at the end of the control valve element, and the adjusting plug is provided with a plug body through hole.

[0024] In the valve type axial impact tool, optionally, the control valve element is provided with a first pressure through hole and a second pressure through hole on the side wall on both sides of the second boss and axially opposite to each other.

[0025] The valve type axial impact tool further comprises a first adjusting spring and a second adjusting spring, the first adjusting spring is elastically connected between the control valve end cover and the second boss, and the second adjusting spring is elastically connected between the second boss and the impact hammer.

[0026] In the valve type axial impact tool, optionally, the inner wall of the impact hammer is provided with a first step for limiting the movement of the control valve assembly, and the outer wall of the impact hammer is axially spaced apart to form a second step and a third step, the second step is in abutment with the pressure bearing ring, and the side wall of the third step is in abutment with the inner wall of the shell.

[0027] In the valve type axial impact tool, optionally, the first joint is threadedly connected with the shell, and the second joint is slidingly connected with the shell.

[0028] The outer wall surface of the second joint is provided with a sliding groove, and a hanging nail is arranged through the sliding groove, so that the second joint is hung on the shell and can slide relative to the shell. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings described below are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0030] Figure 1 The structure sectional view of the valve type axial impact tool provided by the embodiment of the present application;

[0031] Figure 2 The structure schematic view of the control valve outer cylinder of the valve type axial impact tool provided by the embodiment of the present application;

[0032] Figure 3 The structure schematic view of the control valve element of the valve type axial impact tool provided by the embodiment of the present application;

[0033] Figure 4 The structure schematic view of the impact hammer of the valve type axial impact tool provided by the embodiment of the present application;

[0034] Figure 5 A structure schematic view of a first working state of a valve type axial impact tool provided by an embodiment of the present application is shown in the figure;

[0035] Figure 6 A structure schematic view of a second working state of a valve type axial impact tool provided by an embodiment of the present application is shown in the figure;

[0036] Figure 7 A structure schematic view of a third working state of a valve type axial impact tool provided by an embodiment of the present application is shown in the figure;

[0037] Figure 8 A structure schematic view of a fourth working state of a valve type axial impact tool provided by an embodiment of the present application is shown in the figure;

[0038] Figure 9 A structure schematic view of a fifth working state of a valve type axial impact tool provided by an embodiment of the present application is shown in the figure.

[0039] Explanation of reference signs:

[0040] 1 - housing; 2 - first joint; 3 - second joint; 4 - first boss; 5 - first through hole; 6 - hanging nail; 7 - pressure bearing ring; 8 - hammer body; 9 - first step; 10 - second step; 11 - third step; 12 - fourth flow guide hole; 13 - first cavity; 14 - second cavity; 15 - third cavity; 16 - flow guide cylinder; 17 - conical flow guide part; 18 - first conical surface; 19 - first flow guide hole; 20 - control valve core; 21 - control valve end cover; 22 - control valve outer cylinder; 23 - second flow guide hole; 24 - second boss; 25 - third flow guide hole; 26 - first pressure through hole; 27 - second pressure through hole; 28 - adjusting plug; 29 - plug body through hole; 30 - first adjusting spring; 31 - second adjusting spring; 32 - first pressure bearing end surface; 33 - second pressure bearing end surface; 34 - third pressure bearing end surface; 35 - fourth pressure bearing end surface. DETAILED DESCRIPTION

[0041] As described in the background, with the continuous increase of the drilling depth of oil and gas exploitation under the earth's crust, the rock breaking difficulty of deep rock also increases. In the related technology, the axial impact technology is used to assist the drill bit to break the rock of the earth's crust, and there is a problem of low rock breaking efficiency. The inventor found that the main reason for this problem is that the component structure of the drilling tool in the related technology is more, and the connection structure between the components is complex, so that the overall structure length formed by the combination of the drilling tool is too long, which is not suitable for the power drill and is not conducive to the directional control of the operation trajectory when the two are combined for operation, and thus the rock breaking efficiency is low.

[0042] In order to solve the above technical problems, the valve type axial impact tool provided by the embodiment of the present application is characterized in that a plurality of cavities are formed inside the drilling tool, and the hydraulic pressure difference generated in the plurality of cavities by the drilling fluid is used to drive the impact hammer to generate periodic axial impact load on the drill bit, so as to increase the cutting depth of the cutting teeth of the drill bit, and further improve the working efficiency of the valve type axial impact tool, i.e., improve the rock breaking efficiency of the drill bit.

[0043] In order to make the above-mentioned purposes, features and advantages of the embodiments of the present application more obvious and easy to understand, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0044] As shown in Figure 1 The valve type axial impact tool provided by the embodiment of the present application includes a control assembly, a drilling tool joint, an impact hammer, and a shell 1 sleeved on the control assembly, the drilling tool joint and the impact hammer, and the impact hammer is used to provide axial impact force.

[0045] The drilling tool joint includes a first joint 2 and a second joint 3, the first joint 2 is connected to one end of the flow guide cylinder 16 away from the control assembly, and the second joint 3 is connected to one end of the impact hammer away from the control assembly. During drilling operation, the valve type axial impact tool is installed on the upper part of the drill bit, i.e., the second joint 3 is connected to one end of the drill bit away from the rock to be drilled. As shown in the drawings, the first joint 2 is located above the control assembly in the vertical direction, which can also be called the upper joint. The second joint 3 is located below the control assembly, which can also be called the lower joint.

[0046] The first joint 2 is threadedly connected to the shell 1, and the second joint 3 is slidingly connected to the shell 1. Further, the second joint 3 and the shell 1 are connected through a hanging nail 6. The outer wall surface of the second joint is provided with a sliding groove, and the hanging nail 6 is arranged in the sliding groove, so that the second joint 3 is suspended in the central hole of the shell 1 and can slide relative to the shell 1.

[0047] The first boss 4 is arranged on the inner wall of the shell 1, the protruding part of the first boss 4 extends to the inside of the shell 1, and a plurality of first through holes 5 are arranged on the side wall of the shell 1 in the circumferential direction, and the plurality of first through holes 5 are located below the side end surface of the first boss 4 close to the second joint 3. The first through hole 5 is used for connecting the valve type axial impact tool to the annulus of the wellbore, i.e., the downhole environment space outside the valve type axial impact tool.

[0048] Further, the first joint 2, the shell 1 and the second joint 3 are all hollow structures, and the first joint 2, the shell 1 and the second joint 3 have a first joint 2 central hole, a shell 1 central hole and a second joint 3 central hole respectively, and the first joint 2, the shell 1 and the second joint 3 are coaxially communicated in sequence along the vertical direction to form a first central cavity.

[0049] In combination Figure 4 The ram includes a pressure bearing ring 7 and a ram body 8 connected together, the ram body 8 is a hollow rotary body, and further, the ram body 8 is a hollow cylinder.

[0050] The inner wall of the ram body 8 is provided with a first step 9 extending to the inner cavity of the ram body 8, and the outer lateral wall of the ram body 8 is axially spaced apart to provide a second step 10 and a third step 11; the lateral wall of the ram body 8 on the side away from the third step 11 is processed with a first thread, and a plurality of fourth flow guide holes 12 are equidistantly arranged on the lateral wall of the ram body 8 between the second step 10 and the third step 11; the second step 10 is the surface of the second step 10 away from the third step 11, and the third step 11 is the surface close to the second step 10.

[0051] The pressure bearing ring 7 is sleeved on the ram body 8, the inner wall of the pressure bearing ring 7 is provided with a second thread, and the outer wall surface of the pressure bearing ring 7 is attached to the inner wall surface of the shell 1, one end of the pressure bearing ring 7 abuts against the second step 10, and further, the end surface of the pressure bearing ring 7 close to the ram body 8 is threadedly connected with the first thread and the second thread of the second step 10 away from the ram body 8 for the connection between the ram body 8 and the pressure bearing ring 7.

[0052] The first boss 4 is located between the pressure bearing ring 7 and the third step 11; when the end of the second step 10 close to the third step 11 is located in the same horizontal direction as the first boss 4, the lateral wall of the second step 10 is immediately adjacent to the first boss 4 along the hole diameter direction of the central hole of the shell 1, the end surface of the lateral wall of the second step 10 close to the third step 11 is attached to the lateral wall surface of the first boss 4 away from the shell 1, and the surface of the third step 11 away from the ram central hole is attached to the inner wall of the shell 1.

[0053] The end surface of the first joint 2 close to the control assembly and the end surface of the pressure bearing ring 7 close to the control assembly form a first cavity 13 along the axial direction of the shell 1, the end surface of the pressure bearing ring 7 away from the control assembly and the end surface of the first boss 4 close to the control assembly form a second cavity 14 along the axial direction of the shell 1, and the end surface of the first boss 4 away from the control assembly and the end surface of the third step 11 towards the control assembly form a third cavity 15.

[0054] The control assembly comprises a control valve assembly, the control valve assembly and the ram are coaxially arranged in the first central cavity, the control valve is connected to the end of the ram close to the first joint 2, so that when the valve type axial impact tool is used to assist the drilling operation, the control valve assembly can perform linear reciprocating motion with the ram under the hydraulic action in the first central cavity and realize the regulation of the motion state of the ram through the force generated by the contact action with the ram to periodically transmit impact load to the drill bit.

[0055] The control assembly further comprises a flow guide sleeve 16 slidably connected to the control valve assembly, one end of the flow guide sleeve 16 is coaxially fixed in the central hole of the first joint 2, for example, the one end of the flow guide sleeve 16 is coaxially nested in the central hole of the first joint 2, the other end of the flow guide sleeve 16 is connected to the control valve assembly, the flow guide sleeve 16 is provided with a conical flow guide part 17, the conical flow guide part 17 divides the flow guide sleeve 16 into two cavities, wherein the cavity close to the first joint 2 is a first flow guide cavity, and the cavity away from the first joint 2 is a first sliding cavity, the first taper surface 18 of the conical flow guide part 17 faces the first joint 2, and the first taper surface 18 is used as a flow guide surface for the drilling fluid, a plurality of first flow guide holes 19 are arranged on the side wall of the flow guide sleeve 16 on the side of the first taper surface 18 at equal intervals in the circumferential direction, and are used to guide the fluid from the first flow guide cavity.

[0056] The control valve assembly comprises a control valve core 20, a control valve end cover 21 and a control valve outer sleeve 22 sleeved on the control valve core 20, the control valve outer sleeve 22 is coaxially and slidably connected to the end of the flow guide sleeve 16 away from the first joint 2, and when the control valve outer sleeve 22 slides relative to the flow guide sleeve 16, the end of the control valve outer sleeve 22 can extend into the first sliding cavity, and the end surface of the control valve outer sleeve 22 away from the flow guide sleeve 16 abuts against the surface of the pressure bearing ring 7 facing the flow guide sleeve 16.

[0057] In combination Figure 2 , the inner wall of the end of the control valve outer sleeve 22 away from the flow guide sleeve 16 is provided with an internal thread, the outer wall of the end of the ram body 8 close to the flow guide sleeve 16 is provided with an external thread, and the internal thread and the external thread are matched to be used for the threaded fixing between the control valve outer sleeve 22 and the ram body 8.

[0058] The control valve end cover 21 covers the end of the control valve outer sleeve 22 connected to the flow guide sleeve 16, and the control valve end cover 21 is located in the first sliding cavity.

[0059] The control valve outer sleeve 22 is further provided with a plurality of second flow guide holes 23 at equal intervals in the circumferential direction, for example, the plurality of second flow guide holes 23 can be arranged at equal intervals in the circumferential direction on the middle part of the sleeve wall of the control valve outer sleeve 22, and exemplarily, the middle part of the sleeve wall can be a sleeve wall region extending from the end to one third to two thirds of the sleeve length in the axial direction of the control valve outer sleeve 22, including the sleeve wall at one half of the sleeve length.

[0060] As Figure 3As shown, the control valve core 20 can slide relative to the control valve outer cylinder 22, which is a hollow cylinder, and the control valve core 20 is in communication with the hammer body 8, and the inner diameter of the central hole of the control valve core 20 is equal to that of the hammer body 8.

[0061] The side wall of the control valve core 20 near the control valve outer cylinder 22 is provided with a second boss 24, and the outer wall of the second boss 24 abuts the inner wall of the control valve outer cylinder 22.

[0062] The side wall of the second boss 24 is circumferentially spaced apart and provided with a plurality of third flow guide holes 25, and each of the plurality of third flow guide holes 25 is in communication with each second flow guide hole 23.

[0063] The control valve core 20 is provided with a first pressure through hole 26 and a second pressure through hole 27 on the side walls on both sides of the second boss 24.

[0064] Further, the control assembly further comprises an adjusting plug 28, which is fixed to one end of the control valve core 20 near the control valve end cover 21 and is inserted into the central hole of the control valve core 20. Further, the adjusting plug 28 is cylindrical to better match the control valve core 20 and improve installation convenience. The adjusting plug 28 is provided with a plug body through hole 29 in the middle along the axis. In this way, by connecting the adjusting plug 28 provided with the plug body through hole 29 to the control valve core 20, the pressure difference inside and outside the plug body through hole 29 of the adjusting plug 28 can be changed. That is, by changing the fluid flow at both ends of the control valve core 20, the pressure on the end of the control valve core 20 is changed, thereby playing a role in adjusting the movement speed of the control valve core 20.

[0065] The control assembly further comprises adjusting springs, including a first adjusting spring 30 and a second adjusting spring 31. The first adjusting spring 30 and the second adjusting spring 31 are both sleeved on the control valve core 20. The first adjusting spring 30 is elastically connected between the end face of the control valve end cover 21 away from the flow guide cylinder 16 and the end face of the second boss 24 near the flow guide cylinder 16. The second adjusting spring 31 is elastically connected between the end face of the second boss 24 away from the flow guide cylinder 16 and the end face of the hammer body 8 near the flow guide cylinder 16.

[0066] In this way, by arranging the first adjusting spring 30 between the control valve core 20 and the control valve end cover 21, and the second adjusting spring 31 between the control valve core 20 and the hammer body 8, the terminal velocity of the control valve core 20 when moving alone relative to the control valve outer cylinder 22 can be reduced, so as to reduce the impact on the control valve core 20, thereby achieving good buffering protection for the end of the control valve core 20 and prolonging the service life of the control valve core 20.

[0067] As an example, the shell 1 is a sleeve, and the first joint 2 and the second joint 3 are both sleeved by the sleeve, so that the first joint 2 and the second joint 3 are located at both ends of the sleeve.

[0068] The valve type axial impact tool can be applied to drilling operation. The working process of the valve type axial impact tool is described below. During drilling, the valve type axial impact tool is installed on the upper part of the drill bit. A plurality of cavities are formed by the design of the features inside the valve type axial impact tool. The pressure difference is formed by the drilling fluid flowing into the plurality of cavities. The pressure difference can make the components inside the valve type axial impact tool move axially to achieve different movement and working states, so as to realize the linear reciprocating movement of the impact hammer in the valve type axial impact tool and generate periodic impact load through the periodic impact contact with the second joint 3. The periodic impact load is further transmitted to the drill bit, which significantly improves the working efficiency of the drill bit. The valve type axial impact tool further adjusts the movement and working state of the control component and / or the impact hammer through the control component arranged inside.

[0069] The upper part of the drill bit refers to the part of the drill bit that is away from the end of the drill bit that contacts the rock being drilled during drilling.

[0070] During drilling, the drilling fluid is introduced into the valve type axial impact tool. The drilling fluid flows into the inside of the drilling tool from the center hole of the first joint 2, flows into the first flow guide cavity along the axial direction of the flow guide cylinder 16 through the plurality of first flow guide holes 19 arranged on the side wall of the flow guide cylinder 16, and then flows into the center hole of the control valve core 20 and the center hole of the impact hammer body 8 through the second flow guide hole 23 on the control valve outer cylinder 22 and the third flow guide hole 25 on the side wall of the control valve core 20. Finally, the drilling fluid flows out of the valve type axial impact tool through the second joint 3.

[0071] It should be noted that the drilling fluid is a circulating fluid that meets the needs of drilling work with its multiple functions during drilling. For example, the drilling fluid includes clean water, mud, clay-free flushing fluid, emulsion, foam, and compressed air.

[0072] During the tool lowering process, the second joint 3 for connecting with the drill bit is located in the center hole of the outer sleeve. The second joint 3 will extend a distance from the inside of the center hole of the outer sleeve to the outside of the outer sleeve along the axial direction of the outer sleeve under the action of gravity. At the same time, the impact hammer body 8 will move a distance downward along the axial direction of the outer sleeve, that is, there is a clearance between the first boss 4 and the side wall of the impact hammer body 8 near the second joint 3. That is, the position of the fourth flow guide hole 12 is close to the surface of the body wall of the impact hammer body 8 near the second joint 3, which is located below the first boss 4 of the outer sleeve. At this time, the valve type axial impact tool is in the first working state. Figure 5 )。

[0073] In the first working state, the hole in the center of the hammer body 8, the second cavity 14 and the third cavity 15 are connected with the annulus of the wellbore through the first through hole 5 provided on the side wall of the outer sleeve, wherein those skilled in the art can understand that the annulus of the wellbore is the annular space around the drilling tool in the well.

[0074] At the end of the hammer body 8 away from the second joint 3, the end face of the hammer body 8 close to the control valve outer sleeve 22 is the first pressure bearing end face 32, in the axial direction of the hammer body 8, the first pressure bearing end face 32 is subjected to the pressure from the fluid in the first cavity 13, the end face of the hammer body 8 opposite to the first pressure bearing end face 32 and away from the control valve outer sleeve 22 is the second pressure bearing end face 33, at the end of the hammer body 8 close to the second joint 3, the end face of the hammer body 8 away from the second joint 3 is the third pressure bearing end face 34, and the end face of the hammer body 8 close to the second joint 3 is the fourth pressure bearing end face 35, the second pressure bearing end face 33, the third pressure bearing end face 34 and the fourth pressure bearing end face 35 are subjected to the pressure from the fluid in the annulus of the wellbore, the pressure on the second pressure bearing end face 33, the third pressure bearing end face 34 and the fourth pressure bearing end face 35 is less than the pressure on the first pressure bearing end face 32, so that the hammer is subjected to the vertical downward force along the axial direction of the hammer body, so that the hammer remains stationary relative to the outer sleeve, effectively preventing the axial impact of the hammer body on the second joint 3 without contacting the bottom of the well, and preventing the structure from being empty.

[0075] In combination Figure 6 When the valve type axial impact tool is lowered to the bottom of the well, the end of the valve type axial impact tool away from the bottom of the well is connected with the drill string, the drill string drives the outer sleeve to move downward, the fluid passage between the space in the fourth flow guide hole 12 of the hammer body 8 and the second cavity 14 is blocked by the first boss 4. The control valve core 20 is at the lowermost position of the sliding stroke of linear sliding relative to the flow guide cylinder 16 in the vertical direction, i.e. the position closest to the second joint 3; at this time, the end face of the control valve core 20 abuts against the surface of the first step 9 of the hammer body 8, the communication space formed between the second flow guide hole 23 in the side wall of the control valve outer sleeve 22 and the third flow guide hole 25 in the side wall of the control valve core 20 reaches the maximum, i.e. the fluid flow efficiency of the two is the highest, and the valve type axial impact tool is in the second working state.

[0076] In the second working state described above, the first pressure-bearing end face 32 is subjected to pressure from the fluid in the first cavity 13, and the second pressure-bearing end face 33 is subjected to pressure from the fluid in the central hole of the hammer body. At this time, the pressure on the first pressure-bearing end face 32 is greater than the pressure on the second pressure-bearing end face 33. The pressure difference between the first pressure-bearing end face 32 and the second pressure-bearing end face 33 is the first pressure difference. The first pressure difference is the pressure difference generated when the drilling fluid flows through the second guide hole 23 of the outer cylinder 22 of the control valve and the third guide hole 25 of the control valve core 20. The force formed by the first pressure difference is directed downward along the axial direction of the hammer body, which is the force that causes the hammer body to move towards the second connector 3.

[0077] The third pressure-bearing end face 34 is subjected to pressure from the annular fluid in the wellbore, and the fourth pressure-bearing end face 35 is subjected to pressure from the fluid in the central hole of the hammer. The pressure on the third pressure-bearing end face 34 is less than the pressure on the fourth pressure-bearing end face 35. The pressure difference between the third pressure-bearing end face 34 and the fourth pressure-bearing end face 35 is the second pressure difference. The drill bit end is connected to a drill bit nozzle. The second pressure difference is the pressure difference generated when the drilling fluid flows through the drill bit nozzle. The force generated by the second pressure difference is upward along the axial direction of the hammer. When the first pressure difference is less than the second pressure difference, that is, when the pressure difference of the drilling fluid flowing through the second guide hole 23 and the third guide hole 25 of the control valve assembly is less than the pressure difference at the drill bit nozzle, the force on the hammer body is upward along the axial direction, and the hammer body moves upward along the axial direction, that is, the hammer body moves towards the guide tube 16.

[0078] like Figure 7 As shown, when the hammer body moves towards the guide cylinder 16 to its maximum stroke position, the control valve end cap 21 abuts against the guide cylinder 16, the hammer body stops moving, and the tool is in the third working state. Subsequently, the control valve core 20 continues to move towards the guide cylinder 16. During the process of the control valve core 20 continuing to move towards the guide cylinder 16, the fluid flow rate in the flow space formed by the second guide hole 23 and the third guide hole 25 gradually decreases. That is, the flow area of ​​the fluid flowing through the inner wall of the control valve core 20 located at the third guide hole 25 and the control valve outer cylinder 22 located at the second guide hole 23 gradually decreases, which is the first flow area.

[0079] Combination Figure 8 and Figure 9When the control valve core 20 moves to the direction close to the guide cylinder 16 to the end of the control valve core 20 abutting against the control valve end cover 21, the control valve core 20 stops moving, the tool is in the fourth working state, in which the first flow area reaches the minimum, the pressure difference of the drilling fluid at the place is greater than the pressure difference at the drill bit nozzle, that is, the first pressure difference is greater than the second pressure difference, at this time, the overall stress direction of the hammer body is axially downward, the hammer body starts to move downward, that is, to the direction close to the second joint 3. When the hammer body moves to collide with the end of the second joint 3, an axial impact load is generated and transmitted to the drill bit, at this time, the valve type axial impact tool is in the fifth working state.

[0080] Further, the control valve core 20 continues to move downward, the first flow area gradually increases, when the control valve core 20 moves to the end thereof abutting against the first step 9 of the hammer body, the control valve core 20 stops moving, at this time, the tool returns to the second working state. The first flow area reaches the maximum again, the first pressure difference is less than the second pressure difference. At this time, the overall stress direction of the hammer body is axially upward, the hammer body starts to move upward to reset. In this way, the valve type axial impact tool circulates in the second, third, fourth and fifth working states in turn, the hammer body body moves axially reciprocatingly to collide with the second joint 3, to generate a periodic axial impact load on the second joint 3, and then transmitted to the drill bit connected with the second joint 3.

[0081] The valve type axial impact tool provided by the application uses high-pressure drilling fluid as a driving medium, and realizes valve type control of reciprocating movement of the hammer through the control valve assembly arranged inside, so that a stable periodic axial impact load can be generated on the second joint, and then transmitted to the drill bit and increase the rock breaking energy of the drill bit. On the basis of rotary rock breaking, the cutting tooth penetration depth of the drill bit is increased, and the rock breaking efficiency and the rate of penetration are effectively improved. Moreover, the valve type axial impact tool has fewer moving parts, is stable and reliable, has a short overall structure, and has a wide application range.

[0082] In the description of the application, it should be understood that the orientations or positional relationships indicated by the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the application.

[0083] In addition, the terms "first", "second", etc. are used only to describe different instances, and cannot be construed to indicate or imply relative importance or imply the number of indicated technical features. Therefore, the features defined as "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise explicitly specified and limited.

[0084] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and other terms should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrated; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0085] In the present application, unless otherwise explicitly specified and limited, the first feature is above or below the second feature, which can be direct contact between the first and second features, or indirect contact between the first and second features through intermediate medium. Moreover, the first feature above, above and above the second feature can be directly above or obliquely above the first feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The first feature below, below and below the second feature can be directly below or obliquely below the first feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.

[0086] The embodiments or embodiments in the specification are described in a progressive manner, and each embodiment focuses on the difference from other embodiments. The same and similar parts between the embodiments can be referred to each other.

[0087] It should be noted that the "one embodiment", "embodiment", "exemplary embodiment", "some embodiments" and the like mentioned in the specification can include specific features, structures or characteristics, but not necessarily every embodiment includes the specific features, structures or characteristics. In addition, such phrases do not necessarily refer to the same embodiment. In addition, when a specific feature, structure or characteristic is described in combination with an embodiment, it is within the scope of those skilled in the art to realize such features, structures or characteristics in combination with other embodiments explicitly or implicitly described.

[0088] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions recorded in the above embodiments can be modified, or some or all of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A valve-type axial impact tool characterized by, The shell, the drill tool joint, and the flow guide, the control valve assembly and the hammer are arranged in the shell, and the hammer is in sliding fit with the shell; The flow guide, the control valve assembly and the hammer have flow guide holes in sequence, and the outer periphery of the hammer is sleeved with a pressure bearing ring; The drill tool joint comprises a first joint and a second joint, the first joint is installed at the first end of the shell, and the first joint is in abutment with the flow guide; the second joint is installed at the second end of the shell, and the second joint is configured to be in abutment with the hammer when the hammer is at a first position; The first joint, the side of the pressure bearing ring facing the first joint, the outer periphery of the flow guide, the outer periphery of the control valve assembly and the inner surface of the shell form a first cavity; the inner surface of the shell is provided with a first boss, the first boss is located between the pressure bearing ring and the second joint, the side of the pressure bearing ring facing away from the first joint, the inner surface of the shell, the side of the first boss facing the first joint and the outer periphery of the hammer form a second cavity; the side of the first boss facing away from the first joint, the inner surface of the shell and the outer periphery of the hammer form a third cavity; The side wall of the shell is provided with a first through hole to communicate the third cavity with the outside of the shell; The first cavity, the second cavity and the third cavity are configured to form a first pressure difference between the first cavity and the second cavity when drilling fluid flows into the shell, and a second pressure difference between the third cavity and the inside of the hammer, when the first pressure difference is greater than the second pressure difference, the drilling fluid pushes the hammer to slide relative to the shell to impact the second joint to transmit load to the drill bit; The flow guide holes comprise a plurality of first flow guide holes circumferentially spaced apart on the side wall of the flow guide for guiding fluid from the first joint; The control valve assembly comprises a control valve core, a control valve outer cylinder sleeved on the control valve core and a control valve end cover covering the end of the control valve outer cylinder; the control valve outer cylinder is in sliding connection with the flow guide, and the control valve outer cylinder is in abutment with the pressure bearing ring; The flow guide holes comprise second flow guide holes, third flow guide holes and fourth flow guide holes, and a plurality of the second flow guide holes are circumferentially spaced apart on the cylinder wall of the control valve outer cylinder; The side wall of the control valve core is provided with a second boss, and the second boss is in abutment with the control valve outer cylinder; A plurality of third flow guide holes are circumferentially spaced apart on the side wall of the second boss, and each of the third flow guide holes in the plurality of third flow guide holes is in one-to-one communication with each of the second flow guide holes, so that the inside of the control valve assembly is in communication with the first cavity; The fourth flow guide hole is arranged on the side wall of the hammer to communicate the inside of the hammer with the second cavity.

2. The valve-type axial impact tool according to claim 1, wherein The guide cylinder is provided with a guide part, and the guide cylinder is divided into two cavities by the guide part along the axial direction, wherein the cavity close to the first joint is a guide cavity for guiding the fluid from the first joint into the first cavity, and the cavity away from the first joint is a sliding cavity, and the control valve assembly is located in the sliding cavity and can slide relative to the guide cylinder.

3. The valve-type axial impact tool according to claim 2, wherein The guide part is a conical guide part, and a first conical surface of the conical guide part faces the first joint.

4. The valve-type axial impact tool according to claim 1, wherein The valve type axial impact tool further comprises an adjusting plug arranged at the end of the control valve core, and the adjusting plug is provided with a plug body through hole.

5. The valve-type axial impact tool according to claim 4, wherein The control valve core is located on the side wall of the second boss and is provided with a first pressure through hole and a second pressure through hole relative to the axial direction of the control valve core; The valve type axial impact tool further comprises a first adjusting spring and a second adjusting spring, the first adjusting spring is elastically connected between the control valve end cover and the second boss, and the second adjusting spring is elastically connected between the second boss and the impact hammer.

6. The valve-type axial impact tool according to claim 1, wherein The inner wall of the impact hammer is provided with a first step for limiting the movement of the control valve assembly, and the outer wall of the impact hammer is provided with a second step and a third step which are axially spaced, the second step abuts against the pressure bearing ring, and the side wall of the third step is attached to the inner wall of the shell.

7. The valve-type axial impact tool according to claim 1, wherein The first joint is threadedly connected with the shell, and the second joint is slidingly connected with the shell. The outer wall surface of the second joint is provided with a sliding groove, and a hanging nail is arranged through the sliding groove, so that the second joint is hung on the shell and can slide relative to the shell.

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