Underground hydraulic radial tapping device

Abstract

The invention relates to the technical field of tapping tools for oil and gas field development, in particular to an underground hydraulic radial tapping device. Comprising a body; a partition plate is installed in a cavity of the body in a sliding mode, a basin-shaped driving gear and a basin-shaped driven gear are arranged in the lower sealing cavity, the lower end of the transmission shaft penetrates through the partition plate to be fixedly installed together with the basin-shaped driving gear, a liquid flow channel is formed in the body on the right side, and an installation channel is formed in the portion, between the lower sealing cavity and the liquid flow channel, of the body. A piston is installed on the right portion of the installation channel, and a drilling tool is installed on the piston. The hydraulic radial trepanning device is reasonable and compact in structure and convenient to use, the ground pumping pressure reaches a set value, the basin-shaped driving gear moves downwards to be meshed with the basin-shaped driven gear and drives the basin-shaped driven gear to rotate, a drilling tool is carried to rotate, the piston pushes the drilling tool to stretch out in the radial direction under the hydraulic effect, and the purpose of hydraulic radial trepanning is achieved; the device has the advantages of being safe, reliable and easy to control trepanning operation, operation is convenient, and production cost and construction risks are greatly reduced.

Description

Technical Field

[0001] This invention relates to the field of drilling tools for oil and gas field development, and is a downhole hydraulic radial drilling device. Background Technology

[0002] Gas injection enhanced oil recovery (GERD) is a widely used production enhancement technology in major oilfields. However, during field applications, situations frequently arise where the casing pressure exceeds the injection pressure, requiring downhole drilling, unsealing, removal of the tubing string to investigate the cause, and configuration of downhole structures. Furthermore, with the increase in horizontal wells and the length of horizontal sections, severe stuck pipe and blockage of the casing circulation channels are prone to occur during production and development operations, necessitating downhole drilling to establish casing circulation and effectively unslip the pipe. Currently, there are three methods for radial downhole drilling both domestically and internationally: 1. Sandblasting perforation: This method involves complex procedures, numerous construction equipment and facilities, high costs, and is prone to damaging the casing. In addition, the sand sediment during the sandblasting perforation process can pose construction risks to the subsequent packer unsealing operation.

[0003] 2. Downhole punching: This method relies on mechanical or hydraulic impact and extrusion to open holes in the well. The opening effect is not easy to control and it is easy to cause accidental damage to the tubing. At the same time, the recovery effect of the anchoring device and the opening device is difficult to guarantee. Therefore, it is rarely used in actual operation.

[0004] 3. Downhole radial drilling: Because the drilling tools are easily damaged during operation, it is rarely used in actual operations at present.

[0005] Currently, there is no efficient and reliable downhole radial drilling tool in China to effectively solve the above problems.

[0006] Penetrators, a Canadian company, once developed a radial drilling tool that used a double-acting hydraulic cylinder to control the operation of the milling tool and position the drill bit. Radial drilling was achieved under the action of a hydraulic motor. However, at that time, the hydraulic motor had a high speed, the drilling speed control system had a complex structure, and poor field adaptability.

[0007] Patent document CN204113114U discloses a rigid motor drill bit, including a casing, a motor, a drill bit housing, a drill collar, a first stabilizer, a short section, a second stabilizer, and a drill bit. The motor is located at the upper end of the drill bit housing. The lower end of the drill collar is sequentially connected to the first stabilizer, the short section, and the second stabilizer. The drill bit is connected below the second stabilizer. A wireless measurement-while-drilling (MWD) instrument is installed inside the short section. The drill collar is located inside the drill bit housing, which is mounted inside the casing via bearings. A wear-resistant rubber ring is provided between the drill bit housing and the casing. This invention improves the efficiency of downhole horizontal drilling. The drill bit in the drill bit is made of strip-shaped wear-resistant alloy, and the motor's feed direction is axial with the casing, reducing the space occupied by the drill bit. The wear-resistant rubber ring between the casing and the drill bit housing not only reduces friction between the casing and the drill bit housing but also provides a sealing effect. However, this device cannot meet the process requirements of existing downhole hydraulic radial drilling.

[0008] Patent document CN112065279A discloses a mechanical rotary guide tool, including an auxiliary unit, a control unit, and an execution unit. The technical solution is as follows: When the pump pressure is increased, drilling fluid enters the upper cavity of the commutator through the hole at the upper end of the central tube, causing it to compress the lower return spring and move downwards. Due to the engagement of the pin fixed to the upper housing with a special groove on the outer wall of the commutator, the commutator rotates a certain angle while moving downwards, driving the wedge-shaped switch to rotate and return to its upper engagement position. This allows the high-pressure drilling fluid to enter the execution mechanism through the lower opening of the central tube and the radial opening of the switch. The push block moves outwards along the guide joint cavity, causing the guide pusher to expand radially around the rotating shaft and push against the rock wall, thus achieving the tool's guiding function. When the pump pressure is increased again, the commutator will again compress the return spring downwards and drive the switch to rotate a certain angle, causing the lower radial opening of the switch to offset the execution mechanism cavity, disconnecting the connection between the drilling fluid inside the central tube and the execution structure cavity. The guide pusher loses its thrust and retracts under the action of the rock wall, stopping the guiding operation. This invention is a mechanical rotary steering tool that enables control of the wellbore trajectory in complex downhole environments, making it suitable for use in horizontal wells, extended reach wells, and other structural wells. However, this device cannot meet the process requirements of existing downhole hydraulic radial drilling.

[0009] Patent document CN114233194A discloses a split-type hydraulic directional drilling tool assembly for coal mines, comprising a communication sub-section, a power unit, a universal sub-section, a directional drilling sub-section, and a directional drill bit connected in sequence. The directional drilling unit includes a measurement and control component, a hydraulic directional drilling component, and a push-and-adhesion directional drilling component connected in sequence. The measurement and control component is electrically connected to a solenoid valve for controlling the on / off state of the water passage. By controlling the water flow through the solenoid valve, the hydraulic directional drilling component and the push-and-adhesion directional drilling component are radially pushed against the borehole wall along the outer tube of the directional drilling sub-section, causing the outer tube of the directional drilling sub-section to deflect relative to the axis of the universal joint. This invention, through the synergistic effect of the hydraulic directional drilling component and the push-and-adhesion directional drilling component, significantly improves the directional drilling force of the drilling tool assembly, meeting the requirements for borehole trajectory adjustment in deep hole drilling operations. Simultaneously, the magnitude of the directional drilling force can be adjusted through the measurement and control component, enhancing the adaptability of the screw drill to different formations and drilling conditions. However, this device cannot meet the process requirements of existing downhole hydraulic radial drilling.

[0010] Patent document CN204986218U discloses an oil pipe perforator, comprising a body, a support, a cylinder, a locator, and a lower connector. The body includes a retrieval neck and an assembly rod. A groove is axially formed on one side of the assembly rod, and a track is provided within the groove. A bushing mounting hole is radially formed at the upper end of the support, and a bushing is installed within the bushing mounting hole. The support is secured to the side of the assembly rod with the groove by inserting a punch through the hole in the bushing. The lower base of the punch is slidably connected to the track. The locator, equipped with a spring, is installed inside the end of the assembly rod. The spring pushes out the locator after the perforator penetrates the oil pipe or before penetrating it. The cylinder is fitted over the support and the assembly rod. Shear pin holes are provided at both ends of the cylinder, body, and support, and shear pins are inserted into the shear pin holes after the cylinder, body, and support are aligned at both ends. This invention is easy to operate and use, has strong perforation capability, will not puncture the casing, poses no risk of explosion, and can automatically retract after perforation. However, this device has drawbacks: the opening effect is difficult to control, it can easily cause accidental damage to the tubing, and the recovery effect of the opening device is difficult to guarantee. Therefore, it is rarely used in actual operation.

[0011] Patent document CN216370287U discloses a cable lateral drilling tool, which is composed of multiple units connected in series, with the cylindrical shells of adjacent units connected by threaded engagement. The multiple units specifically include an electronic circuit unit, a hydraulic power unit, a pushing unit, and an execution unit. Each execution unit has a pushing unit at each end. The pushing unit includes a pushing assembly that is telescopically oriented. The execution unit includes a main spindle drill bit that is telescopically oriented, with the extension direction of the main spindle drill bit opposite to that of the pushing assembly. This invention achieves automated in-pipe operations through integrated control of the electronic circuit unit; the combination of hydraulic and mechanical transmission results in a simple and low-cost transmission method; and the telescopic arrangement of the main spindle drill bit and pushing assembly makes the overall tool structure compact, which helps protect the drill bit and improves its service life, making it practical. However, this device is not suitable for horizontal well operations, and the control system is still immature. Summary of the Invention

[0012] This invention provides a downhole hydraulic radial drilling device that overcomes the shortcomings of the prior art. It effectively solves the problems of existing devices being difficult to control during drilling operations, having high costs, being prone to damaging the casing, and posing construction risks, and thus failing to meet the process requirements of existing downhole hydraulic radial drilling.

[0013] The technical solution of the present invention is achieved through the following measures: a downhole hydraulic radial drilling device, comprising a body and a drive shaft; a partition plate is slidably installed in the cavity of the body, dividing the cavity into an upper sealing cavity and a lower sealing cavity; a matching basin-shaped driving gear and a basin-shaped driven gear are provided in the lower sealing cavity; the lower end of the drive shaft passes through the partition plate and is fixedly installed together with the basin-shaped driving gear; a vertical liquid flow channel is provided in the body on the right side; a horizontally connected installation channel is provided on the body between the lower sealing cavity and the liquid flow channel; a piston is installed on the right side of the installation channel; a drill bit is installed on the left end of the piston; the drill bit passes through the installation channel and is fixedly installed together with the basin-shaped driven gear; an extension hole communicating with the lower sealing cavity is provided at the left end of the body; the left end of the drill bit is located in the extension hole; an annular straightening and limiting device is fixedly installed at the left end of the installation channel; a horizontal tension spring is fixedly connected between the annular straightening and limiting device and the piston.

[0014] The following are further optimizations and / or improvements to the above-mentioned technical solution: A cover plate is fixedly installed on the top of the upper sealing cavity. Mounting holes are provided in the middle of the cover plate and the partition plate. The lower end of the drive shaft passes through the mounting holes on the cover plate and the partition plate in sequence and is fixedly installed together with the basin-shaped drive gear. An annular groove is provided on the inner wall of the partition plate located at the mounting hole. At least two elastic protrusions are symmetrically fixedly installed on the lower outer side of the drive shaft along the circumference. The elastic protrusions are installed in the annular groove of the partition plate, and there is a gap between the elastic protrusions and the bottom wall of the annular groove. At least two vertical tension springs are symmetrically fixedly connected between the cover plate and the partition plate. A liquid flow hole is provided on the body between the upper sealing cavity and the liquid flow channel.

[0015] The aforementioned rotary connection device is fixedly installed on the left end face of the piston, and the right end of the drill bit is installed on the rotary connection device.

[0016] The aforementioned rotary connection device is a bearing housing. The drilling tool includes a drill rod and a drill bit. The right end of the drill rod is mounted on the bearing housing, and the right part of the drill rod is located in the installation channel. The pot-shaped driven gear is fixedly mounted in the middle of the drill rod, and the drill bit is fixedly mounted on the left end of the drill rod, with the drill bit located in the protruding hole.

[0017] The aforementioned straightening bearing sleeve is fixedly installed inside the protruding hole, and the drill bit is located inside the straightening bearing sleeve.

[0018] The above also includes an adapter and a screw motor. The upper outer side of the adapter and the lower inner side of the screw motor are fixedly installed together. The lower inner side of the adapter and the upper outer side of the body are fixedly installed together. An adapter sleeve is fixedly installed at the lower end of the power output shaft of the screw motor. The adapter sleeve is located inside the adapter. At least two sliders are symmetrically fixed along the circumference on the upper outer side of the drive shaft. The lower inner wall of the adapter sleeve is provided with a number of grooves equal to the number of sliders along the shaft. The upper part of the drive shaft and the lower part of the adapter sleeve are installed together by the sliders and the grooves.

[0019] The above-mentioned sealing rings are installed between the partition plate and the body, between the cover plate and the body, between the cover plate and the drive shaft, and on the outside of the piston; or / and, a sand-proof hydraulic anchor is fixedly installed at the lower end of the body, the liquid flow channel of the body and the liquid flow channel of the sand-proof hydraulic anchor are connected, and a back pressure valve is fixedly installed on the liquid flow channel of the sand-proof hydraulic anchor; or / and, a pressure limiting valve is fixedly installed on the liquid flow hole, and a pressure limiting valve is fixedly installed at the right end of the liquid flow channel.

[0020] This invention has a reasonable and compact structure and is easy to use. When the tool reaches the set position, the ground pumping equipment increases the system displacement to the set value, the hydraulic anchor is anchored, the pot-shaped drive gear moves downward and meshes with the pot-shaped driven gear, driving the pot-shaped driven gear to rotate. The pot-shaped driven gear carries the drill bit to rotate, and at the same time, the piston pushes the drill bit to extend radially under hydraulic action, thereby achieving the purpose of hydraulic radial drilling. It has the characteristics of safety, reliability and easy control of drilling operation, which facilitates operation, greatly reduces production costs and construction risks, and can well meet the process requirements of existing downhole hydraulic radial drilling. Attached Figure Description

[0021] Appendix Figure 1 This is a schematic diagram of the front cross-sectional structure of the present invention.

[0022] The codes in the attached diagram are as follows: 1 is the main body, 2 is the drive shaft, 3 is the upper sealing cavity, 4 is the lower sealing cavity, 5 is the pot-shaped driving gear, 6 is the pot-shaped driven gear, 7 is the liquid flow channel, 8 is the installation channel, 9 is the piston, 10 is the extension hole, 11 is the annular straightening and limiting device, 12 is the horizontal tension spring, 13 is the cover plate, 14 is the partition plate, 15 is the installation hole, 16 is the annular groove, 17 is the elastic protrusion, 18 is the vertical tension spring, 19 is the liquid flow hole, 20 is the rotary connection device, 21 is the drill rod, 22 is the drill bit, and 23 is the straightening bearing sleeve. Detailed Implementation

[0023] The present invention is not limited to the following embodiments, and the specific implementation can be determined according to the technical solution of the present invention and the actual situation.

[0024] In this invention, for ease of description, the description of the relative positions of the components is based on the appendix to the specification. Figure 1 The layout is described using a diagrammatic method, such as the positional relationships of front, back, top, bottom, left, and right, which are based on the instructions attached. Figure 1 The orientation of the layout is determined by the direction of the map.

[0025] The present invention will be further described below with reference to embodiments and accompanying drawings: As attached Figure 1As shown, the downhole hydraulic radial drilling device includes a body 1 and a drive shaft 2. A partition plate 14 is slidably installed in the cavity of the body 1, dividing the cavity into an upper sealing cavity 3 and a lower sealing cavity 4. In the lower sealing cavity 4, there are a matching basin-shaped driving gear 5 and a basin-shaped driven gear 6. The lower end of the drive shaft 2 passes through the partition plate 14 and is fixedly installed together with the basin-shaped driving gear 5. A vertical liquid flow channel 7 is provided in the body 1 on the right side. A horizontally connected installation channel 8 is provided on the body 1 between the lower sealing cavity 4 and the liquid flow channel 7. A piston 9 is installed on the right side of the installation channel 8. A drill bit is installed on the left end of the piston 9. The drill bit passes through the installation channel 8 and is fixedly installed together with the basin-shaped driven gear 6. An extension hole 10 communicating with the lower sealing cavity 4 is provided on the left end of the body 1. The left end of the drill bit is located in the extension hole 10. An annular straightening and limiting device 11 is fixedly installed on the left end of the installation channel 8. A horizontal tension spring 12 is fixedly connected between the annular straightening and limiting device 11 and the piston 9. The pot-shaped drive gear 5 and pot-shaped driven gear 6 are existing common and known components; the annular centering and limiting device 11 can be a common centering sleeve; thus, in use, the downhole hydraulic radial drilling device of the present invention is connected to the well tool string. When the tool reaches the set position, the surface pumping equipment increases the system displacement to the set value, the sand-proof hydraulic anchor is anchored, the pot-shaped drive gear 5 descends and meshes with the pot-shaped driven gear 6 and drives the pot-shaped driven gear 6 to rotate. The pot-shaped driven gear 6 carries the drill string to rotate, and at the same time, the piston 9 pushes the drill string to extend radially under hydraulic action, thereby achieving the purpose of hydraulic radial drilling. It has the characteristics of safety and reliability and easy control of drilling operation, which facilitates operation, greatly reduces production costs and construction risks, and can well meet the process requirements of existing downhole hydraulic radial drilling.

[0026] The above-mentioned downhole hydraulic radial orifice opening device can be further optimized and / or improved according to actual needs: As attached Figure 1As shown, a cover plate 13 is fixedly installed on the top of the upper sealing cavity 3. Mounting holes 15 are respectively provided in the middle of the cover plate 13 and the partition plate 14. The lower end of the drive shaft 2 passes through the mounting holes 15 on the cover plate 13 and the partition plate 14 in sequence and is fixedly installed together with the basin-shaped drive gear 5. An annular groove 16 is provided along the circumference on the inner wall of the partition plate 14 located at the mounting hole 15. At least two elastic protrusions 17 are symmetrically fixedly installed along the circumference on the lower outer side of the drive shaft 2. The elastic protrusions 17 are installed in the annular groove 16 of the partition plate 14, and there is a gap between the elastic protrusions 17 and the bottom wall of the annular groove 16. At least two vertical tension springs 18 are symmetrically fixedly connected between the cover plate 13 and the partition plate 14. A liquid flow hole 19 is provided on the body 1 between the upper sealing cavity 3 and the liquid flow channel 7. The cover plate 13 can be fixedly installed to the inner wall of the body 1 by means of a locking block or a locking ring; the elastic protrusion 17 can also be a torsion spring. In order to facilitate the installation of the torsion spring in the annular slide groove 16, an installation opening can be provided at the upper part of the annular slide groove 16; the partition plate 14 located at the mounting hole 15 can also be installed with the corresponding drive shaft 2 through a keyway and a key. The drive shaft 2 can rotate relative to the partition plate 14, and the drive shaft 2 can also move with the up and down movement of the partition plate 14; in this way, when the tool reaches the set position, the ground pumping equipment increases the system discharge to the set value, the sand-proof hydraulic anchor is anchored, and the liquid in the liquid flow channel 7 enters the upper sealing cavity 3, squeezing and distributing. The partition 14 moves downward, causing the drive shaft 2 to move downward, which in turn meshes the pot-shaped drive gear 5 and the pot-shaped driven gear 6. This starts the drive shaft 2 to rotate, and the elastic protrusion 17 rotates within the annular groove 16 of the partition 14. The drive shaft 2 then drives the pot-shaped drive gear 5 to rotate, which in turn drives the pot-shaped driven gear 6 to rotate. The pot-shaped driven gear 6 carries the drill bit and rotates together, causing the drill bit to open a hole. After the hole is opened, the sand-proof hydraulic anchor is released, and the pressure in the upper sealing cavity 3 decreases. Under the action of the vertical tension spring 18, the partition 14 moves the drive shaft 2 upward, causing the pot-shaped drive gear 5 and the pot-shaped driven gear 6 to separate.

[0027] As attached Figure 1 As shown, a rotary connecting device 20 is fixedly installed on the left end face of the piston 9, and the right end of the drill bit is installed on the rotary connecting device 20. This facilitates the rotation of the drill bit.

[0028] As needed, the rotary connection device 20 is a bearing housing. The drilling tool includes a drill rod 21 and a drill bit 22. The right end of the drill rod 21 is mounted on the bearing housing, and the right part of the drill rod 21 is located in the mounting channel 8. The pot-shaped driven gear 6 is fixedly mounted in the middle of the drill rod 21, and the drill bit 22 is fixedly mounted on the left end of the drill rod 21, located in the protrusion hole 10. Thus, when the pot-shaped driving gear 5 and the pot-shaped driven gear 6 mesh together, the transmission shaft 2 drives the pot-shaped driving gear 5 to rotate, the pot-shaped driving gear 5 drives the pot-shaped driven gear 6 to rotate, and the pot-shaped driven gear 6 carries the drill rod 21 to rotate together. The right end of the drill rod 21 rotates within the bearing housing.

[0029] As attached Figure 1 As shown, a centering bearing sleeve 23 is fixedly installed inside the protrusion hole 10, and the drill bit 22 is located inside the centering bearing sleeve 23. This facilitates the rotation and extension of the drill bit 22 during operation. The centering bearing sleeve 23 can be a conventionally known bearing housing.

[0030] As needed, it also includes an adapter and a screw motor. The upper outer side of the adapter and the lower inner side of the screw motor are fixedly installed together. The lower inner side of the adapter and the upper outer side of the body 1 are fixedly installed together. An adapter sleeve is fixedly installed at the lower end of the power output shaft of the screw motor. The adapter sleeve is located inside the adapter. At least two sliders are symmetrically fixed along the circumference on the upper outer side of the drive shaft 2. The lower inner wall of the adapter sleeve is provided with a number of grooves equal to the number of sliders along the shaft. The upper part of the drive shaft 2 and the lower part of the adapter sleeve are installed together by the sliders and the grooves. The screw motor is a known and commonly used one, and can be a low-speed screw motor with a speed of 20 rpm to 60 rpm. When the power output shaft of the screw motor rotates, it can drive the conversion sleeve to rotate, thereby driving the transmission shaft 2 to rotate. At the same time, when the partition plate 14 moves downward, the partition plate 14 can drive the transmission shaft 2 to move downward. The slider on the transmission shaft 2 can move downward along the slide groove in the conversion sleeve, so that the basin-shaped driving gear 5 and the basin-shaped driven gear 6 mesh together. The basin-shaped driving gear 5 drives the basin-shaped driven gear 6 to rotate, and the basin-shaped driven gear 6 carries the drill bit to rotate together.

[0031] As needed, a sealing ring is installed between the partition plate 14 and the body 1, between the cover plate 13 and the body 1, between the cover plate 13 and the drive shaft 2, and on the outside of the piston 9; or / and, a sand-proof hydraulic anchor is fixedly installed at the lower end of the body 1, the liquid flow channel 7 of the body 1 is connected to the liquid flow channel of the sand-proof hydraulic anchor, and a back pressure valve is fixedly installed on the liquid flow channel of the sand-proof hydraulic anchor; or / and, a pressure limiting valve is fixedly installed on the liquid flow hole 19, and a pressure limiting valve is fixedly installed on the right end of the liquid flow channel 7. The sand-proof hydraulic anchor is a known and commonly used one; the lower outer side of the body 1 can be fixedly installed together with the upper inner side of the sand-proof hydraulic anchor; the conversion joint converts the fluid from the screw motor outlet to the liquid flow channel 7 (eccentric flow channel) on the right side of the body 1, and then into the liquid flow channel of the sand-proof hydraulic anchor.

[0032] The functions and roles of each component in this invention are as follows: Component 1: The screw motor is a low-speed screw motor, which is connected to the main body 1 by threaded connection, and provides power for the downhole hydraulic radial drilling device of the present invention. The drive shaft assembly, universal joint assembly, motor assembly (low-speed screw motor), downhole hydraulic radial drilling device of the present invention and sand-proof hydraulic anchor are installed together in sequence from top to bottom.

[0033] Component 2: Drive shaft 2, which can be connected to the power output end of the screw motor through a conversion sleeve with a built-in spline structure, can drive the pot-shaped drive gear 5 to rotate, and can slide axially within the conversion sleeve.

[0034] 1) Adapter: The upper part connects to the screw motor and has a fluid flow chamber inside; the lower part connects to the main body 1.

[0035] 2) Flow channel conversion chamber: The fluid from the screw motor outlet flows sequentially into the liquid flow chamber of the conversion joint, the liquid flow channel 7 (eccentric flow channel) on the right side of the body 1, and then into the liquid flow channel of the sand-proof hydraulic anchor.

[0036] 3) Cover plate 13 and partition plate 14: Cover plate 13 and partition plate 14, together with vertical tension spring 18, constitute the reset spring cavity (upper sealing cavity 3). Double-stage O-ring pressure seals can be installed on the inner and outer walls of cover plate 13 and partition plate 14 to seal the upper sealing cavity 3. The outer ring of cover plate 13 can be axially limited by a snap ring against the inner wall of body 1. Partition plate 14 can drive the drive shaft 2 and the drive bevel gear to move axially.

[0037] Component 3: Active pot gear, the upper part of the drive shaft 2 (spindle) may be designed with splines, which are axially slidably connected to the conversion sleeve; the lower part of the drive shaft 2 (spindle) is a smooth rod, which is sealed at the partition plate 14.

[0038] The downhole hydraulic radial drilling device of the present invention can adjust the position of the basin-shaped drive gear 5 by changing the system pressure, and control the meshing and disengagement of the basin-shaped drive gear 5 and the basin-shaped driven gear 6, thereby realizing the output and cut-off of the drill bit power.

[0039] Component 4: Liquid flow channel 7. Fluid enters the liquid flow channel 7 (eccentric flow channel) on the right side of the main body 1 through the screw motor, and splits into three paths: one path enters the upper sealing cavity 3, drives the partition plate 14 to move down, thereby driving the transmission shaft 2 and the basin-shaped drive gear 5 to move down together, so that the basin-shaped drive gear 5 and the basin-shaped driven gear 6 mesh together; one path enters the installation channel 8, drives the piston 9 and the drill bit to move to the left; and one path drives the sand-proof hydraulic anchor, so that the sand-proof hydraulic anchor is anchored, the basin-shaped drive gear 5 and the basin-shaped driven gear 6 mesh, and the drill bit drills radially.

[0040] Component 5: Horizontal tension spring 12 drives the basin-shaped driven gear 6 to reset.

[0041] Component 6: Basin-shaped drive gear 5. After the sand-proof hydraulic anchor is anchored, the system pressure drives the basin-shaped drive gear 5 to move downward and mesh with the basin-shaped driven gear 6, converting the axial rotation of the screw into the radial rotation of the transmission gear, driving the drill bit to make radial holes at the set position.

[0042] Component 7: Piston 9, used in conjunction with horizontal tension spring 12, with a double-stage O-ring seal installed on the outer surface of piston 9; when the system pressure is higher than the set value, the liquid pushes piston 9, and the drill assembly extends out of the extension hole 10 of the body 1; when the system pressure is released, horizontal tension spring 12 pushes piston 9 and drill assembly back into the body 1.

[0043] Component 8: The basin-shaped driven gear 6, after meshing with the basin-shaped driving gear 5, converts the axial rotation of the transmission shaft 2 into the radial rotation of the basin-shaped driven gear 6, thereby driving the drill bit to perform radial drilling.

[0044] Component 9: Drill string assembly, with both ends stably supported by a centralizing bearing sleeve 23 and a rotary connecting device 20 (which can also be a sealed bearing or a sleeve bearing) mounted on the main body 1. The drill string is connected to the piston 9 via the rotary connecting device 20. When the piston 9 is not rotating, the drill string can rotate and drill under the drive of the bevel gear. A horizontal tension spring 12 is connected between the annular centralizing limiting device 11 (centralizing bushing or centralizing sleeve) and the piston 9. After the system pressure is released, the drill string retracts into the main body 1 under the action of the horizontal tension spring 12. The drill bit 22 can be a carbide drill bit to prevent accidental damage to the drill string during operation.

[0045] Component 10: Centering bearing sleeve 23, which is freely rotatable and has a sealing function, and provides radial rotation support and centering for the drill bit. Snap rings can be installed on the left and right sides of the centering bearing sleeve 23 to prevent radial movement.

[0046] Component 11: Annular centering and limiting device 11, which limits the drill bit in the left and right directions, and at the same time limits the running position of piston 9.

[0047] Component 12: Sand-proof hydraulic anchor (in-pipe hydraulic anchor), used to anchor the downhole hydraulic radial opening device of the present invention. When the inner diameter is large, the sand-proof hydraulic anchor can be selected, and when the inner diameter is small, the in-pipe hydraulic anchor can be selected.

[0048] Component 13: Install channel 8. The flow channel size is determined according to the cross-sectional area and volume of piston 9. It should be ensured that the drill bit extends out of the body 1 only after it is fully anchored by the sand-proof hydraulic anchor.

[0049] Component 14: Sand-proof hydraulic anchor fluid flow channel. The flow channel size is determined based on the cross-sectional area of ​​the anchor claw, the total volume of the anchor claw cavity, the horizontal tension spring 12, the piston 9, etc. The cross-sectional area of ​​the sand-proof hydraulic anchor fluid flow channel and the installation channel 8 are determined. It should be ensured that the sand-proof hydraulic anchor is fully anchored before the pot-shaped gear set (pot-shaped driving gear 5 and pot-shaped driven gear 6) meshes.

[0050] Component 15: Back pressure valve. The operating parameters of the back pressure valve are set according to the pressure parameters required for normal operation of the operating system.

[0051] Advantages of this invention: 1. The upper part of the main body 1 of the present invention is connected to a low-speed screw motor (the speed can be stabilized at 20rpm to 60rpm). The screw motor provides power and the axial rotation of the screw motor is converted into the radial rotation of the drill bit through the bowl gear set (bowl-shaped driving gear 5 and bowl-shaped driven gear 6).

[0052] 2. The lower part of the main body 1 of the present invention is connected to a sand-proof hydraulic anchor (in-pipe hydraulic anchor), which can provide stable working conditions for downhole radial drilling tools after anchoring.

[0053] 3. A back pressure valve is installed at the bottom of the sand-proof hydraulic anchor (in-pipe hydraulic anchor) to control the pressure of the working system.

[0054] 4. When the tool reaches the set position, the ground pumping equipment increases the system discharge to the set value, the sand-proof hydraulic anchor is anchored, the pot-shaped drive gear 5 descends to the set position and meshes with the pot-shaped driven gear 6 and drives the pot-shaped driven gear 6 (carrying the drill bit) to rotate, and the piston 9 pushes the drill bit to extend radially under hydraulic action and drills a hole at the set position.

[0055] 5. The straightening bearing sleeve 23 of the present invention is beneficial to the stability of the drill bit during the drilling process; the preferred material and shape of the drill bit 22 prevent accidental damage to the drill bit during operation; during the drilling process, the system liquid pressure drives the piston 9 and the drill bit to perform stable radial drilling.

[0056] 6. After the radial hole is opened, when the discharge rate in the pipe is lower than the set discharge rate, the drill bit is reset under the action of the horizontal tension spring 12, and the drill bit 22 retracts into the centering bearing sleeve 23; the pot-shaped drive gear 5 is reset under the action of the vertical tension spring 18 and disengages from the pot-shaped driven gear 6; the sand-proof hydraulic anchor is released from anchoring.

[0057] 7. This invention is a highly efficient and reliable tool for downhole radial drilling. It is used to perform downhole drilling operations in situations such as gas injection casing pressure overpressure, requiring unsealing and removal of the tubing string to investigate the cause, or serious stuck drill bit incidents during sand flushing, unblocking, or other operations where it is impossible to establish an oil-casing circulation channel. This establishes an oil-casing connection channel to facilitate the smooth progress of subsequent work.

[0058] The working process of this invention is as follows: Well MHD10XX is a carbon dioxide injection well in an oilfield. During the injection process, the casing pressure exceeded the limit, requiring the well to be unsealed, the tubing string to be removed to investigate the cause, and downhole structures to be installed. Due to the packer separation, the tubing and casing are not connected, necessitating the creation of a circulation channel by drilling a hole in the tubing to facilitate subsequent operations.

[0059] Using the downhole hydraulic radial perforation device of the present invention for operation: 1. Preferred low-speed screw motor: speed 20rpm to 60rpm; 2. Carbide drill bits are preferred; 3. Connect the downhole hydraulic radial drilling device of the present invention to the well tool string and perform a visual inspection; conduct a surface test according to the designed circulation displacement and observe the status of the tool string: under the circulation displacement, the drill string and the sand control hydraulic anchor should be in a non-working state. 4. Conduct ground tests according to the designed hole displacement and observe the status of the tool string: Under the hole displacement, the sand-control hydraulic anchor should be in the anchored state, and the drill bit should extend out of the body 1 and rotate; test the extension state, elongation and rotation of the drill bit, as well as the extension state and elongation of the sand-control hydraulic anchor. 5. The tool string enters the well at the designed circulation displacement, and the pot-shaped driving gear 5 and the pot-shaped driven gear 6 are disengaged at this time; 6. After the tool string reaches the designed opening, slowly increase the circulation rate to the opening rate, and use the sand-proof hydraulic anchor to anchor the tool string. 7. Piston 9 pushes the drill bit to compress the horizontal tension spring 12, positioning it at the drilling position; 8. Under the pressure of the system, the pot-shaped drive gear 5 overcomes the action of the vertical tension spring 18 and moves downward, meshing with the pot-shaped driven gear 6, driving the drill bit to open the hole; 9. After the drilling operation is completed, restore the system pressure to the circulating pressure; 10. Release the hydraulic anchor for sand control; 11. The drill bit stops rotating and retracts back into the body 1; 12. Under the action of the vertical tension spring 18, the basin-shaped driving gear 5 disengages from the basin-shaped driven gear 6 and resets; 13. Lift toolchain.

[0060] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the needs of different situations.

Claims

1. A downhole hydraulic radial drilling device, characterized in that... It includes a main body and a drive shaft. A partition plate is slidably installed in the cavity of the main body, dividing the cavity into an upper sealing cavity and a lower sealing cavity. In the lower sealing cavity, there are mating basin-shaped driving gear and basin-shaped driven gear. The lower end of the drive shaft passes through the partition plate and is fixedly installed with the basin-shaped driving gear. A vertical liquid flow channel is provided in the main body on the right side. A horizontally connected installation channel is provided on the main body between the lower sealing cavity and the liquid flow channel. A piston is installed on the right side of the installation channel. A drill bit is installed on the left end of the piston. The drill bit passes through the installation channel and is fixedly installed with the basin-shaped driven gear. An extension hole communicating with the lower sealing cavity is provided on the left end of the main body. The left end of the drill bit is located in the extension hole. An annular straightening and limiting device is fixedly installed on the left end of the installation channel. A horizontal tension spring is fixedly connected between the annular straightening and limiting device and the piston.

2. The downhole hydraulic radial drilling device according to claim 1, characterized in that... A cover plate is fixedly installed on the top of the upper sealing cavity. Mounting holes are provided in the middle of the cover plate and the partition plate respectively. The lower end of the drive shaft passes through the mounting holes on the cover plate and the partition plate in sequence and is fixedly installed together with the basin-shaped drive gear. An annular groove is provided on the inner wall of the partition plate located at the mounting hole. At least two elastic protrusions are symmetrically fixedly installed on the lower outer side of the drive shaft along the circumference. The elastic protrusions are installed in the annular groove of the partition plate, and there is a gap between the elastic protrusions and the bottom wall of the annular groove. At least two vertical tension springs are symmetrically fixedly connected between the cover plate and the partition plate. A liquid flow hole is provided on the body between the upper sealing cavity and the liquid flow channel.

3. The downhole hydraulic radial drilling device according to claim 1 or 2, characterized in that... A rotary connection device is fixedly installed on the left end face of the piston, and the right end of the drill bit is installed on the rotary connection device.

4. The downhole hydraulic radial drilling device according to claim 3, characterized in that... The rotary connection device is a bearing seat. The drilling tool includes a drill rod and a drill bit. The right end of the drill rod is mounted on the bearing seat. The right part of the drill rod is located in the installation channel. The pot-shaped driven gear is fixedly mounted in the middle of the drill rod. The drill bit is fixedly mounted on the left end of the drill rod and is located in the protruding hole.

5. The downhole hydraulic radial drilling device according to claim 4, characterized in that... A centering bearing sleeve is fixedly installed inside the protruding hole, and the drill bit is located inside the centering bearing sleeve.

6. The downhole hydraulic radial drilling device according to claim 1 or 2, characterized in that... It also includes an adapter and a screw motor. The upper outer side of the adapter and the lower inner side of the screw motor are fixedly installed together. The lower inner side of the adapter and the upper outer side of the body are fixedly installed together. An adapter sleeve is fixedly installed at the lower end of the power output shaft of the screw motor. The adapter sleeve is located inside the adapter. At least two sliders are symmetrically fixed along the circumference on the upper outer side of the drive shaft. The lower inner wall of the adapter sleeve is provided with grooves along the shaft, the number of which is equal to the number of sliders. The upper part of the drive shaft and the lower part of the adapter sleeve are installed together by the sliders and the grooves.

7. The downhole hydraulic radial drilling device according to claim 3, characterized in that... It also includes an adapter and a screw motor. The upper outer side of the adapter and the lower inner side of the screw motor are fixedly installed together. The lower inner side of the adapter and the upper outer side of the body are fixedly installed together. An adapter sleeve is fixedly installed at the lower end of the power output shaft of the screw motor. The adapter sleeve is located inside the adapter. At least two sliders are symmetrically fixed along the circumference on the upper outer side of the drive shaft. The lower inner wall of the adapter sleeve is provided with grooves along the shaft, the number of which is equal to the number of sliders. The upper part of the drive shaft and the lower part of the adapter sleeve are installed together by the sliders and the grooves.

8. The downhole hydraulic radial drilling device according to claim 5, characterized in that... It also includes an adapter and a screw motor. The upper outer side of the adapter and the lower inner side of the screw motor are fixedly installed together. The lower inner side of the adapter and the upper outer side of the body are fixedly installed together. An adapter sleeve is fixedly installed at the lower end of the power output shaft of the screw motor. The adapter sleeve is located inside the adapter. At least two sliders are symmetrically fixed along the circumference on the upper outer side of the drive shaft. The lower inner wall of the adapter sleeve is provided with grooves along the shaft, the number of which is equal to the number of sliders. The upper part of the drive shaft and the lower part of the adapter sleeve are installed together by the sliders and the grooves.

9. The downhole hydraulic radial drilling device according to claim 2, characterized in that... A sealing ring is installed between the partition plate and the body, a sealing ring is installed between the cover plate and the body, a sealing ring is installed between the cover plate and the drive shaft, and a sealing ring is installed on the outside of the piston; or / and, a sand-proof hydraulic anchor is fixedly installed at the lower end of the body, the liquid flow channel of the body and the liquid flow channel of the sand-proof hydraulic anchor are connected, and a back pressure valve is fixedly installed on the liquid flow channel of the sand-proof hydraulic anchor; or / and, a pressure limiting valve is fixedly installed on the liquid flow hole, and a pressure limiting valve is fixedly installed at the right end of the liquid flow channel.

10. The downhole hydraulic radial drilling device according to claim 8, characterized in that... A sealing ring is installed between the partition plate and the body, a sealing ring is installed between the cover plate and the body, a sealing ring is installed between the cover plate and the drive shaft, and a sealing ring is installed on the outside of the piston; or / and, a sand-proof hydraulic anchor is fixedly installed at the lower end of the body, the liquid flow channel of the body and the liquid flow channel of the sand-proof hydraulic anchor are connected, and a back pressure valve is fixedly installed on the liquid flow channel of the sand-proof hydraulic anchor; or / and, a pressure limiting valve is fixedly installed on the liquid flow hole, and a pressure limiting valve is fixedly installed at the right end of the liquid flow channel.

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