CN114856414A

CN114856414A - Underground power drilling tool

Info

Publication number: CN114856414A
Application number: CN202210549537.8A
Authority: CN
Inventors: 胡东泽; 赵海茜
Original assignee: Sichuan Zhong'an Jiasheng Petroleum Technology Co ltd
Current assignee: Sichuan Zhong'an Jiasheng Petroleum Technology Co ltd
Priority date: 2022-05-20
Filing date: 2022-05-20
Publication date: 2022-08-05

Abstract

The invention discloses an underground power drilling tool, which comprises a bypass valve and a power motor, wherein the power motor comprises a first sleeve, a rotating rod and an elastic sleeve, the first sleeve is coaxially arranged in the first sleeve, the rotating rod is in a spiral line shape, a plurality of protruding blades are formed at the end part of the rotating rod, the elastic sleeve is sleeved outside the rotating rod, the outer wall of the elastic sleeve is tightly attached to the inner wall of the first sleeve, and a plurality of spiral grooves are formed in the inner wall of the elastic sleeve.

Description

Underground power drilling tool

Technical Field

The invention relates to the technical field of downhole drilling tools, in particular to a downhole power drilling tool.

Background

Conventional drilling equipment uses an uphole motor as the output power to transmit power to the drill bit downhole through a single rod connection. When the drill bit reaches a certain depth, the loss of the torque, the rotating speed and the power transmitted from the well through each section of single rod begins to be reduced; as the drilling depth increases, the load on the single rod of the power take-off and power transmission also begins to increase, and the failure rate of the equipment also begins to rise. The factors are accumulated to bring the effects that the drilling cost per meter is improved, and the drillable depth of drilling is finally limited, so how to additionally install the underground power module becomes a new research and development direction, the underground power drilling tools are divided into electric drilling tools and turbine drilling tools at present, wherein the number of the turbine drilling tools is large, and the turbine drilling tools have the soft characteristic of high speed and large torque, have no transverse vibration and have high mechanical drilling speed; the all-metal turbine drilling tool is high-temperature resistant and is suitable for operation in deep wells and high-temperature environments; the drilling fluid is insensitive to the oil-based drilling fluid and can adapt to work in the high-density drilling fluid.

However, because the power generated by a single turbine in the traditional turbine drilling tool is too small, more than hundreds of sets of turbines are generally required to be connected in series, the drilling tool is very long, the application range is very small, the installation and adjustment of the axial clearance are complicated, the axial load becomes very large due to more turbine sets and a longer main shaft, and the complex structure and the overlong volume ensure that the bearing has short service life, more wearing parts and shorter service life of a drill bit.

Disclosure of Invention

The present invention is directed to a downhole power drill that solves the problems set forth above in the background.

The invention is realized by the following technical scheme:

an underground power drilling tool comprises a bypass valve and a power motor, wherein the power motor comprises a first sleeve with a hollow inner part, a rotating rod which is coaxially arranged in the first sleeve and is of a spiral line type and the end part of which is provided with a plurality of convex blades, an elastic sleeve which is sleeved outside the rotating rod, the outer wall of which is tightly attached to the inner wall of the first sleeve and the inner wall of which is provided with a plurality of spiral grooves, the interior of the elastic sleeve is provided with a reinforcing layer along the axial direction, the reinforcing layer comprises a plurality of reinforcing ribs which are arranged in the elastic sleeve in a penetrating way and are mutually staggered with the spiral grooves, and a metal net which is arranged among the plurality of reinforcing ribs and is used for tensioning the reinforcing ribs and forming an annular structure, the elastic sleeve is engaged with the rotating rod in a conjugate manner to form a spiral cavity, a plurality of guide seams are arranged in the spiral cavity along the direction of the spiral path, the ratio of the number of the convex blades of the rotating rod to the number of the spiral grooves of the elastic sleeve is N/(N + 1).

At present, because the power generated by a single turbine in the traditional turbine drilling tool is too small, more than one hundred sets of turbines are generally required to be connected in series, the drilling tool is very long, the application range is very small, the installation and adjustment of axial clearance are more complicated, meanwhile, the axial load becomes very large due to more turbine sets and longer main shafts, the service life of a bearing is short, a plurality of wearing parts are provided, the service life of a drill bit is short due to the complex structure and the overlong volume, furthermore, because the power generated by the single turbine in the turbine drilling tool is too small, more than one hundred sets of turbines are generally required to be connected in series, the drilling tool is very long, the application range of the turbine drilling tool is greatly limited, the axial load becomes very large due to more turbine sets and longer main shafts, in order to deal with the situation, a thrust shaft and a middle bearing need to be additionally arranged inside, a core pipe needs to be additionally arranged under some special conditions, and the structure of the turbine drilling tool is very complex, the complex structure will affect the failure rate of the worm gear drilling tool, thereby reducing the stability of the worm gear drilling tool, and the worm gear drilling tool is driven only by the flow rate of the flushing fluid rather than the pressure, so that the rotating speed is high and the torque is small, thereby affecting the drilling work of the drilling tool, based on the scheme, the scheme uses the pressure of the driving medium (drilling fluid or slurry) to generate power, generally speaking, the high pressure can generate large torque, and the rotating speed is easier to control, specifically, the power motor adopts a rotating rod arranged in a first outer sleeve, and an elastic sleeve engaged with the rotating rod in a conjugate way is arranged at the position corresponding to the rotating rod in the first outer sleeve, so that a volume motor structure is formed by the rotating rod and the elastic sleeve, further, a plurality of groups of turbines and a plurality of groups of center rods are not used, but a rotating rod with extremely high strength and a spiral line type is used as a rotor (similar to a gear, the end part of the elastic sleeve is provided with a plurality of blades), the elastic sleeve is taken as a stator elastic body and is matched and meshed with an external gear of the rotating rod through a spiral groove arranged in the elastic sleeve, the number of the raised blades of the rotating rod is N/(N + 1) compared with the number of the spiral grooves of the elastic sleeve, namely, the elastic sleeve is provided with one more spiral groove (equivalent to the external gear matched with the rotating rod) than the rotor, so the number of the raised blades of the rotating rod is different from that of the spiral groove of the elastic sleeve by 1, a cavity filled with drilling fluid is generated between the elastic sleeve and the rotating rod when the elastic sleeve is in a well, the cavity can be like a wedge when being pressed, and the driving medium can not be compressed, and the force applied to the top of the wedge can cause the rotor (namely the rotating rod) to rotate, thereby greatly reducing the complexity of the mechanical structure of the turbine drilling tool, leading a power motor to have firmer structural design, have longer service life and can bear severe drilling conditions, the drilling speed is improved to the maximum extent, the performance which can not be achieved by the traditional motor is provided, the design generates unprecedented torque and power level, the drilling cost per meter in severe environment is reduced, furthermore, when the rotating rod rotates in the elastic sleeve in a planet way, the rotating rod often generates relative extrusion friction with the inside of the elastic sleeve, after long-time work, the elastic sleeve is easy to wear and lose efficacy, thereby influencing the leakage and the failure of a drilling tool motor, on the basis of the scheme, the reinforced layer is arranged in the elastic sleeve, and the reinforced layer comprises the reinforced rib and the metal net, because the reinforced rib is arranged at the position where the inner part of the elastic sleeve is mutually staggered with the spiral groove, namely the bulge part between two adjacent spiral grooves, when the rotating rod rotates in the elastic sleeve to extrude the bulge part between the adjacent spiral grooves, the reinforced rib can provide a supporting rigidity for the bulge part, in addition, a plurality of guide seams are arranged in a spiral cavity formed between the elastic sleeve and the rotating rod along the path direction of the spiral path, so that when drilling fluid flows in the spiral cavity, the driving medium is guided, the rotating rod is pushed to rotate by the spiral cavity more smoothly, the phenomenon that the rotating rod and the elastic sleeve are abraded and accelerated due to the fact that particle substances in the driving medium block the spiral cavity due to the fact that the flow velocity of the drilling fluid is too full is avoided, and the comprehensive contact between the elastic sleeve and the rotating rod can also be avoided to a certain extent, thereby reducing the abrasion of the elastic sleeve and prolonging the service life of the elastic sleeve.

Furthermore, the bypass valve is arranged at the end part of the power motor and comprises a valve cavity arranged inside, a filling port with the bottom end connected with the first sleeve in a threaded manner, a valve body with bypass holes arranged on the periphery, a valve seat coaxially arranged at the bottom of the valve cavity and communicated with a through hole arranged in the middle of the bottom of the valve body, a valve core with the top end abutting against a step part at the upper part of the valve cavity and flow holes arranged on the periphery corresponding to the positions of the bypass holes, and a spring positioned between the valve seat and the valve core and used for elastically supporting the valve core, wherein the bottom end of the valve cavity is sleeved on the valve seat in a sliding manner, the horn-shaped flow channel is arranged in the middle of the valve seat, the spring is in a free state and elastically supports the valve core, so that the flow holes on the valve core are communicated with the bypass holes, when the drive medium enters the valve cavity through the filling port during working, when the flow and the pressure of the driving medium reach preset values, the driving medium can push the valve core to compress the spring so as to enable the valve core to slide downwards on the outer surface of the valve seat, so that the circulation hole and the bypass hole are staggered to close the bypass hole, at the moment, the driving medium can flow into the power motor through the valve core and the valve seat so as to drive the power motor to rotate, and when the flow and the pressure of the driving medium do not reach the preset values, the pressure of the driving medium on the valve core cannot overcome the spring force of the spring and the static friction force of the valve core and the valve seat, the spring always elastically supports the valve core, so that the bypass hole is ensured to be communicated with the circulation hole, and the driving medium is used for allowing drilling fluid to fill a drill string from an annulus when drilling into a shaft or discharge the drilling fluid when drilling out.

Furthermore, a sealing assembly is further arranged in a region where the valve seat and the valve core coincide, the sealing assembly comprises a hollow groove annularly formed on the outer wall of the valve seat, a sealing ring coaxially sleeved in the hollow groove and provided with a plurality of notches on the outer ring surface to form a saw-toothed shape, and a plurality of lantern rings sleeved in the notches on the outer ring surface of the sealing ring, the lantern rings are hollow and filled with cooling liquid, it needs to be noted that most of researches on the downhole power drilling tool are carried out on a power motor at present, and a bypass valve is not deeply researched, but the bypass valve is used as a part at the uppermost part of the downhole power drilling tool, the stability of the structure of the bypass valve is very important for the working state of the downhole power drilling tool, and the sealing failure between the valve core and the valve seat is very easily caused because the valve core and the valve seat frequently slide relatively when the current bypass valve works, therefore, the working effect of the bypass valve is influenced, and the normal work of the power drilling tool is further influenced, on the basis of the scheme, a sealing assembly is arranged between a valve seat and a valve core, the sealing between the valve core and the valve seat can be always ensured when the valve core slides on the valve seat through the arrangement of the sealing assembly, the driving of a driving medium to a power motor is avoided, and the driving of the driving medium to the power motor is influenced, particularly, the sealing assembly in the scheme comprises a hollow groove, a sealing ring and a spring, when the valve core slides up and down on the outer surface of the valve seat, the sealing ring can generate extrusion deformation under the action of friction force, so that the sealing ring is tightly attached to the inner part of the valve core to fill a gap between the valve seat and the valve core, further, when the sealing ring deforms, the lantern ring can be extruded, and because cooling liquid is stored in the lantern ring, when heat is generated between the sealing ring and the valve core due to sliding friction, the coolant liquid can absorb the heat, in order to avoid the sealing washer that leads to the heat to gather and make to become invalid after the long-time work of sealing washer, thereby the life of extension sealing washer, the while has injected the coolant liquid in the lantern ring, and because the compression deformation volume of coolant liquid itself is limited, therefore it can carry out certain restriction to the deformation volume of sealing washer, avoid the too big sealing washer deformation volume cause with case between frictional force increase and then cause the sealing washer extrusion failure, thereby improve the result of use of sealing washer, and then ensure seal assembly's sealed effect, with this guarantee bypass valve normal work, avoid the power drilling tool to cause the drilling fluid decompression because of taking place to leak between case and the disk seat, and lead to the power drilling tool trouble.

Further, the drill bit further comprises a transmission assembly positioned at one end of the power motor far away from the bypass valve, wherein the transmission assembly is used for transmitting the rotating torque of the power motor to the drill bit.

Furthermore, the transmission assembly comprises a second sleeve, a transmission shaft and a coupling, the end part of the second sleeve is in threaded connection with one end of the first outer sleeve far away from the bypass valve, the transmission shaft is coaxially arranged in the second sleeve, one end of the transmission shaft close to the first outer sleeve is connected with the rotating rod through the coupling, the coupling is a universal coupling and is mainly used for connecting the rotating rod which does planetary rotation with the transmission shaft which does fixed-shaft rotation, the planar planetary motion of the motor rotating rod is converted into the fixed-shaft rotation of the transmission shaft, and meanwhile, the output torque and the rotating speed of the power motor are transmitted to the drill bit through the transmission shaft.

Preferably, a plurality of discharge holes are axially formed in the outer surface of one end, far away from the first sleeve, of the second sleeve, the axis direction of any discharge hole is tangent to the outer surface of the first sleeve, the discharge holes are used for discharging a driving medium (drilling liquid or slurry) flowing through the power motor after entering the second sleeve so as to realize self circulation of the driving medium, and the discharge holes are tangent to the second sleeve, so that the driving medium can be rapidly discharged under the action of self pressure, the blockage of the discharge holes cannot be caused, the loss of a well repairing material in the driving medium is avoided, and further the well repairing material in the driving medium can effectively repair cracks at the bottom of a well.

Compared with the prior art, the invention has the following advantages and beneficial effects:

(1) the rotary rod is arranged in the first outer sleeve, the elastic sleeve which is in conjugate engagement with the rotary rod is arranged in the position, corresponding to the rotary rod, in the first outer sleeve in a fitting manner, so that the positive displacement motor is formed through the rotary rod and the elastic sleeve, and compared with the traditional drilling motor, the positive displacement motor has a firmer structural design, is longer in service life, can bear severe drilling conditions, improves the drilling Rate (ROP) to the maximum extent, and provides performance which cannot be achieved by the traditional motor;

(2) the rotating rod and the elastic sleeve are both made by presetting, and the matching degree between the rotating rod and the rotor is good, so that the mechanical and hydraulic efficiency of the power drilling tool is greatly improved, and the failure rate of the drilling tool is reduced;

(3) the rotary steering device is more adaptive to the existing rotary steering drill bit, provides higher torque, more stable rotating speed and lower failure rate for the rotary steering drill bit, and can also provide energy for underground electric signal transmission and improve the accuracy of the rotary steering device;

(4) according to the invention, the reinforcing layer is arranged in the elastic sleeve, and the reinforcing layer comprises the reinforcing rib and the metal net, the reinforcing rib is arranged at the position where the reinforcing rib is arranged in the elastic sleeve and the spiral grooves in a penetrating manner, namely the bulge part between two adjacent spiral grooves, so that when the rotating rod rotates in the elastic sleeve to extrude the bulge part between the adjacent spiral grooves, the reinforcing rib can provide a supporting rigidity for the bulge part to avoid the failure caused by excessive deformation of the bulge part, meanwhile, the metal net is positioned between the reinforcing ribs and forms an annular structure with the reinforcing ribs, the effect of a hoop on the reinforcing rib can be realized, the elastic sleeve is further wrapped and reinforced, the leakage failure between the elastic sleeve and the rotating rod due to excessive radial deformation of the elastic sleeve is avoided, and the service life of the power drilling tool is further prolonged;

(5) according to the invention, through the arrangement of the guide seam, the driving medium can be guided when the drilling fluid flows in the spiral cavity, so that the drilling fluid can more smoothly push the rotating rod to rotate through the spiral cavity, the phenomenon that the rotating rod and the elastic sleeve are abraded and accelerated due to the fact that the spiral cavity is blocked by granular substances in the driving medium due to the fact that the flow speed of the drilling fluid is too full is avoided, and the comprehensive contact between the elastic sleeve and the rotating rod can also be avoided to a certain extent, so that the abrasion of the elastic sleeve is reduced, and the service life of the elastic sleeve is further prolonged;

(6) the sealing assembly comprises a hollow groove, a sealing ring and a spring, wherein when a valve core slides up and down on the outer surface of a valve seat, the sealing ring can be extruded and deformed under the action of friction force, so that the sealing ring is tightly attached to the inside of the valve core to fill a gap between the valve seat and the valve core, further, when the sealing ring deforms, the sleeve ring can be extruded, and because cooling liquid is stored in the sleeve ring, when heat is generated between the sealing ring and the valve core due to sliding friction, the cooling liquid can absorb the heat, so that the sealing ring is prevented from being failed due to heat accumulation after the sealing ring works for a long time, the service life of the sealing ring is prolonged, meanwhile, the cooling liquid is filled in the sleeve ring, and because the compression deformation of the cooling liquid is limited, the deformation of the sealing ring can be limited to a certain extent, and the phenomenon that the friction force between the sealing ring and the valve core is increased to further cause the extrusion failure of the sealing ring due to overlarge deformation of the sealing ring is avoided, therefore, the using effect of the sealing ring is improved, the sealing effect of the sealing assembly is further ensured, the normal work of the bypass valve is ensured, and the failure of the power drilling tool caused by the pressure loss of the drilling fluid due to the leakage between the valve core and the valve seat of the power drilling tool is avoided.

Drawings

The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principles of the invention. In the drawings:

FIG. 1 is a schematic structural view (bypass valve and power motor) of embodiment 1 of the present invention;

FIG. 2 is a schematic view of the A-A viewing direction structure of the present invention;

FIG. 3 is an enlarged view of a portion of the structure of the present invention at B;

FIG. 4 is a schematic view of a partial valve seat structure according to the present invention;

FIG. 5 is an enlarged view of a portion of the structure of the present invention at C;

FIG. 6 is a schematic structural view (bypass valve, power motor and transmission assembly) of embodiment 2 of the present invention;

fig. 7 is a schematic view of embodiment 3 of the present invention.

In the drawings, the names of the components corresponding to the reference numerals are as follows:

1. a bypass valve; 10. a valve body; 100. a bypass orifice; 11. a valve seat; 12. a valve core; 120. a flow-through hole; 13. a spring; 14. a seal assembly; 140. an empty groove; 141. a seal ring; 142. a collar; 2. a power motor; 20. a first sleeve; 21. a rotating rod; 22. an elastic sleeve; 220. a reinforcing layer; 221. reinforcing ribs; 222. a metal mesh; 23. a helical cavity; 230. guiding the seam; 3. a transmission assembly; 30. a second sleeve; 300. a discharge hole; 31. a drive shaft; 32. a coupling is provided.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to examples and accompanying drawings, and the exemplary embodiments and descriptions thereof are only used for explaining the present invention and are not meant to limit the present invention.

First, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation and be operated, and thus, should not be construed as limiting the present invention.

Example 1

As shown in fig. 1 to 5, a downhole power drill includes a bypass valve 1 and a power motor 2, and is characterized in that the power motor 2 includes a first sleeve 20 having a hollow interior, a rotating rod 21 coaxially disposed in the first sleeve 20 and having a spiral shape and a plurality of protruding blades formed at an end portion thereof, an elastic sleeve 22 sleeved outside the rotating rod 21, having an outer wall closely attached to an inner wall of the first sleeve 20 and a plurality of spiral grooves formed at an inner wall thereof, a reinforcing layer 220 disposed inside the elastic sleeve 22 along an axial direction thereof, the reinforcing layer 220 including a plurality of reinforcing ribs 221 disposed in the elastic sleeve 22 and staggered with the spiral grooves, a metal mesh 222 disposed between the plurality of reinforcing ribs 221 and used for tensioning the reinforcing ribs 221 and forming a ring structure, the elastic sleeve 22 and the rotating rod 21 being in conjugate engagement to form a spiral cavity 23, a plurality of guide slits 230 disposed inside the spiral cavity 23 along a spiral path direction thereof, the ratio of the number of the convex blades of the rotating rod 21 to the number of the spiral grooves of the elastic sleeve 22 is N/(N + 1), wherein N is greater than or equal to 1, and it should be noted that in order to adapt to a rated drill, the present scheme preferably adopts 5/6 proportions of the number of the rotor/stator blades (i.e. the ratio of the number of the convex blades of the rotating rod 21 to the number of the spiral grooves of the elastic sleeve 22 is 5/6).

At present, because the power generated by a single turbine in the traditional turbine drilling tool is too small, more than one hundred sets of turbines are generally required to be connected in series, the drilling tool is very long, the application range is very small, the installation and adjustment of axial clearance are more complicated, meanwhile, the axial load becomes very large due to more turbine sets and longer main shafts, the service life of a bearing is short, a plurality of wearing parts are provided, the service life of a drill bit is short due to the complex structure and the overlong volume, furthermore, because the power generated by the single turbine in the turbine drilling tool is too small, more than one hundred sets of turbines are generally required to be connected in series, the drilling tool is very long, the application range of the turbine drilling tool is greatly limited, the axial load becomes very large due to more turbine sets and longer main shafts, in order to deal with the situation, a thrust shaft and a middle bearing need to be additionally arranged inside, a core pipe needs to be additionally arranged under some special conditions, and the structure of the turbine drilling tool is very complex, the complex structure will affect the failure rate of the worm gear drilling tool, thereby reducing the stability of the worm gear drilling tool, and at the same time, the worm gear drilling tool is driven only by the flow rate of the flushing fluid rather than the pressure, so that the rotating speed is high and the torque is small, thereby affecting the drilling work of the drilling tool, based on which, the scheme uses the pressure of the driving medium (drilling fluid or slurry) to generate power, generally speaking, the high pressure can generate large torque, and the rotating speed is easier to control, specifically, the power motor 2 adopts a rotating rod 21 arranged in the first outer sleeve, and an elastic sleeve 22 conjugated and meshed with the rotating rod 21 is arranged in the position corresponding to the rotating rod 21 in the first outer sleeve, so as to form a positive displacement motor structure by the rotating rod 21 and the elastic sleeve 22, further, a plurality of groups of turbines and a plurality of center rods are not used, but a rotating rod 21 with extremely high strength and a spiral line type is used as a rotor (similar to a gear, the end part of the elastic sleeve 22 is provided with a plurality of blades), the elastic sleeve 22 is taken as a stator elastic body and is matched and meshed with the external gear of the rotating rod 21 through the spiral groove arranged in the elastic sleeve, and as the ratio of the number of the raised blades of the rotating rod 21 to the number of the spiral groove of the elastic sleeve 22 is N/(N + 1), namely, the number of the raised blades of the rotating rod is 1 compared with that of the external gear matched with the rotating rod 21, a cavity filled with drilling fluid is generated between the elastic sleeve 22 and the rotating rod 21 in a downhole, the cavity is like a wedge when being pressed, and as the driving medium cannot be compressed, the force applied to the top of the wedge causes the rotor (namely the rotating rod 21) to rotate, thereby greatly reducing the complexity of the mechanical structure of the turbine drilling tool, leading the power motor 2 to have stronger structural design and longer service life, the design generates unprecedented torque and power level, reduces drilling cost per meter in severe environment, further, when the rotating rod 21 rotates in the elastic sleeve 22 in a planet way, the rotating rod often generates relative extrusion friction with the inside of the elastic sleeve 22, after long-time working, the elastic sleeve 22 is easy to wear and lose efficacy, thereby influencing the leakage and the failure of a drilling tool motor, based on the scheme, the reinforcing layer 220 is arranged in the elastic sleeve 22, and because the reinforcing layer 220 comprises the reinforcing ribs 221 and the metal net 222, because the reinforcing ribs 221 are arranged at the positions where the inner part of the elastic sleeve 22 and the spiral grooves are mutually staggered, namely the bulges between two adjacent spiral grooves, when the rotating rod 21 rotates in the elastic sleeve 22 to extrude the bulges between the adjacent spiral grooves, the reinforcing rib 221 can provide a supporting rigidity for the protruding portion to avoid failure due to excessive deformation, and at the same time, the metal mesh 222 is located between the reinforcing ribs 221 and forms an annular structure with the reinforcing ribs 221, so as to achieve a hoop effect on the reinforcing ribs 221, further achieve a wrapping reinforcement for the elastic sleeve 22, and avoid sealing failure between the elastic sleeve 22 and the rotating rod 21 due to excessive radial deformation, it should be noted that a plurality of guide slits 230 are formed in the spiral cavity 23 formed between the elastic sleeve 22 and the rotating rod 21 along the direction of the spiral path, through the arrangement of the guide slits 230, when the drilling fluid flows in the spiral cavity 23, the driving medium is guided, so that the driving medium is more smoothly guided when the rotating rod 21 is pushed to rotate by the spiral cavity 23, and the abrasion acceleration between the rotating rod 21 and the elastic sleeve 22 due to the blockage of the spiral cavity 23 by particulate matter in the driving medium due to over-full flow velocity of the drilling fluid is avoided, the overall contact between the elastic sleeve 22 and the rotating rod 21 can be avoided to a certain extent, thereby reducing the abrasion of the elastic sleeve 22 and prolonging the service life thereof.

Specifically, the bypass valve 1 is arranged at the end of the power motor 2, and the bypass valve 1 comprises a valve cavity arranged inside, a valve body 10 with a bottom end in threaded connection with a first sleeve 20, a top end provided with an injection port communicated with the valve cavity, a periphery provided with bypass holes 100, a valve seat 11 coaxially arranged at the bottom of the valve cavity and an inside communicated with a through hole arranged in the middle of the bottom of the valve body 10, a bottom end slidably sleeved on the valve seat 11, a trumpet-shaped flow channel arranged in the middle of the inside, a valve core 12 with a top end abutting against a step part at the upper part of the valve cavity and flow holes 120 arranged on the periphery corresponding to the positions of the bypass holes 100, and a spring 13 positioned between the valve seat 11 and the valve core 12 and used for elastically supporting the valve core 12, wherein in an initial state, the spring 13 is in a free state and elastically supports the valve core 12, so that the flow holes 120 on the valve core 12 are communicated with the bypass holes 100, when the drilling fluid drilling device works, when a driving medium enters the valve cavity through the injection port, when the flow rate and the pressure of the driving medium reach preset values, the driving medium can push the valve core 12 to compress the spring 13, so that the valve core 12 slides downwards on the outer surface of the valve seat 11, the flow hole 120 and the bypass hole 100 are dislocated, and the bypass hole 100 is closed, at the moment, the driving medium can flow into the power motor 2 through the valve core 12 and the valve seat 11 to drive the power motor 2 to rotate, and when the flow rate and the pressure of the driving medium do not reach the preset values, the pressure of the driving medium on the valve core 12 cannot overcome the force of the spring 13 and the static friction force of the valve core 12 and the valve seat 11, the spring 13 always elastically supports the valve core 12, so that the bypass hole 100 is communicated with the flow hole 120, and the drilling fluid is used for allowing the drilling fluid to be filled into a drill string from an annular space when drilling a shaft, or discharged when drilling.

Specifically, a sealing assembly 14 is further disposed in a region where the valve seat 11 and the valve element 12 overlap, the sealing assembly 14 includes a hollow groove 140 circumferentially disposed on an outer wall of the valve seat 11, a sealing ring 141 coaxially disposed in the hollow groove 140 and having a plurality of notches formed on an outer circumferential surface thereof and forming a saw-tooth shape, and a plurality of collars 142 disposed in the notches of an outer circumferential surface of the sealing ring 141, and the collars 142 are hollow and filled with a cooling liquid, it should be noted that most of the current downhole power drill researches are carried out on the power motor 2, and the bypass valve 1 is not deeply researched, but the bypass valve 1 is a component at the uppermost part of the downhole power drill, and the stability of the structure of the bypass valve 1 plays an important role in the working state of the downhole power drill, and because the valve element 12 and the valve seat 11 inside the bypass valve 1 often slide relative to each other during the working, therefore, sealing failure between the valve core 12 and the valve seat 11 is easily caused, so that the working effect of the bypass valve 1 is influenced, and further the normal operation of the power drilling tool is influenced, on the basis, the sealing component 14 is particularly arranged between the valve seat 11 and the valve core 12, through the arrangement of the sealing component 14, when the valve core 12 slides on the valve seat 11, the sealing between the valve core 12 and the valve seat 11 can be always ensured, the leakage between the valve core 12 and the valve seat 11 is avoided, and the driving of a driving medium on the power motor 2 is influenced, particularly, the sealing component 14 in the scheme comprises a hollow groove 140, a sealing ring 141 and a spring 13, when the valve core 12 slides up and down on the outer surface of the valve seat 11, the sealing ring 141 can be extruded and deformed under the action of friction force, so that the sealing ring 141 is tightly attached to the inner part of the valve core 12 to fill a gap between the valve seat 11 and the valve core 12, furthermore, when the sealing ring 141 deforms, the collar 142 is squeezed, and the collar 142 stores cooling liquid, so that when heat is generated between the sealing ring 141 and the valve element 12 due to sliding friction, the cooling liquid can absorb heat to prevent the sealing ring 141 from failing due to heat accumulation after the sealing ring 141 works for a long time, so that the service life of the sealing ring 141 is prolonged, meanwhile, the collar 142 stores cooling liquid, and because the amount of compression deformation of the cooling liquid is limited, the amount of deformation of the sealing ring 141 can be limited to a certain extent, so that the phenomenon that the sealing ring 141 is squeezed to fail due to the fact that the deformation of the sealing ring 141 is too large and the friction force between the sealing ring 141 and the valve element 12 is increased is avoided, so that the use effect of the sealing ring 141 is improved, the sealing effect of the sealing assembly 14 is ensured, the normal work of the bypass valve 1 is ensured, and the drilling fluid pressure loss caused by leakage between the valve element 12 and the valve seat 11 of a power drill is avoided, resulting in power drill failure.

Example 2

On the basis of the embodiment 1, as shown in fig. 6, the drilling machine further comprises a transmission assembly 3 positioned at one end of the power motor 2 far away from the bypass valve 1, wherein the transmission assembly 3 is used for transmitting the rotation torque of the power motor 2 to the drill bit; the transmission assembly 3 comprises a second sleeve 30, a transmission shaft 31 and a coupling 32, wherein the end of the second sleeve 30 is in threaded connection with one end of the first outer sleeve far away from the bypass valve 1, the transmission shaft 31 is coaxially arranged inside the second sleeve 30, one end of the transmission shaft 31 close to the first outer sleeve is connected with the rotating rod 21 through the coupling 32, the coupling 32 is a universal coupling 32 and is mainly used for connecting the rotating rod 21 which makes planetary rotation with the transmission shaft 31 which makes fixed-shaft rotation, the plane planetary motion of the motor rotating rod 21 is converted into fixed-shaft rotation of the transmission shaft 31, and meanwhile, the output torque and the rotating speed of the power motor 2 are transmitted to a drill bit through the transmission shaft 31.

Preferably, the outer surface of one end of the second sleeve 30, which is far away from the first sleeve 20, is axially provided with a plurality of discharge holes 300, the axial direction of any one of the discharge holes 300 is tangential to the outer surface of the first sleeve 20, the discharge holes 300 are used for discharging a driving medium (drilling fluid or slurry) flowing through the power motor 2 after entering the second sleeve 30, so as to realize self-circulation of the driving medium, and the discharge holes 300 are tangential to the second sleeve 30, so that the driving medium can be rapidly discharged under the action of self pressure without causing blockage of the discharge holes 300, thereby avoiding loss of a well repairing material in the driving medium, and further enabling the well repairing material carried in the driving medium to effectively repair a crack at the bottom of a well.

EXAMPLE 3

To facilitate understanding of the present solution, as shown in fig. 7, since different numbers of rotor/stator blade ratios will bring completely different speed/torque parameter effects, the best rotor/stator blade ratio is sought, and for this purpose, the applicant specifically simulated the torque/speed parameter ratio in 5 sets of ratios 1/2, 3/4, 5/6, 7/8, 9/10, so that when the number of rotor/stator blades is increased from the single blade arrangement of the conventional motor to the multiple blades, the bit speed is decreased and the torque is increased, and in order to adapt to the rated bit, we selected the rotor/stator blade number of 5/6 ratio.

The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are merely exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. The underground power drilling tool comprises a bypass valve (1) and a power motor (2), and is characterized in that the power motor (2) comprises a first sleeve (20) which is hollow inside, a rotating rod (21) which is coaxially arranged in the first sleeve (20) and is of a spiral line type and the end part of which forms a plurality of protruding blades, an elastic sleeve (22) which is sleeved outside the rotating rod (21), the outer wall of which is tightly attached to the inner wall of the first sleeve (20) and the inner wall of which is provided with a plurality of spiral grooves, a reinforcing layer (220) is arranged inside the elastic sleeve (22) along the axial direction of the elastic sleeve, the reinforcing layer (220) comprises a plurality of reinforcing ribs (221) which are arranged in the elastic sleeve (22) in a penetrating way and are mutually staggered with the positions of the spiral grooves, a metal net (222) which is arranged among the plurality of reinforcing ribs (221) and is used for tensioning the reinforcing ribs (221) and forming an annular structure, and the spiral cavity (23) is formed by conjugate engagement of the elastic sleeve (22) and the rotating rod (21), the interior of the helical cavity (23) is provided with a plurality of guide slits (230) along the direction of the helical path thereof.

2. A downhole motor according to claim 1, wherein the ratio of the number of lobes of the rotary rod (21) to the number of helical grooves of the resilient sleeve (22) is N/(N + 1).

3. A downhole motor according to claim 1, wherein the bypass valve (1) is provided at the end of the power motor (2), the bypass valve (1) comprises a valve cavity arranged inside, a valve body (10) with the bottom end connected with a first sleeve (20) in a threaded manner, the top end provided with an injection port communicated with the valve cavity, and the periphery provided with bypass holes (100), a valve seat (11) coaxially arranged at the bottom of the valve cavity and internally communicated with a through hole arranged in the middle of the bottom of the valve body (10), a valve core (12) with the bottom end sleeved on the valve seat (11) in a sliding manner, a horn-shaped flow channel arranged in the middle of the inside, the top end abutting against the step part at the upper part of the valve cavity, and circulation holes (120) arranged at the position of the periphery corresponding to the bypass holes (100), and a spring (13) which is positioned between the valve seat (11) and the valve core (12) and is used for elastically supporting the valve core (12).

4. A downhole motor according to claim 3, wherein a sealing assembly (14) is further provided in a region where the valve seat (11) and the valve element (12) overlap, the sealing assembly (14) comprises a hollow groove (140) circumferentially formed on an outer wall of the valve seat (11), a plurality of notched sealing rings (141) coaxially sleeved on inner and outer circumferential surfaces of the hollow groove (140) and forming a saw-tooth shape, and a plurality of collars (142) sleeved on the notches of the outer circumferential surfaces of the sealing rings (141), and the collars (142) are hollow and filled with cooling fluid.

5. A downhole motor according to claim 1, further comprising a transmission assembly (3) at an end of the power motor (2) remote from the bypass valve (1), the transmission assembly (3) being adapted to transmit the rotational torque of the power motor (2) to the drill bit.

6. A downhole motor according to claim 5, wherein the transmission assembly (3) comprises a second sleeve (30), a transmission shaft (31) and a coupling (32), the end of the second sleeve (30) being threadedly connected to the end of the first outer sleeve (20) remote from the bypass valve (1), the transmission shaft (31) being coaxially arranged inside the second sleeve (30) and having its end near the first outer sleeve (20) connected to the rotary rod (21) via the coupling (32), the coupling (32) being a universal coupling.

7. A downhole motor according to claim 4, wherein the second sleeve (30) has a plurality of axially extending discharge holes (300) formed in an outer surface of an end thereof remote from the first sleeve (20), the axial direction of any of the discharge holes (300) being tangential to the outer surface of the first sleeve (20).