Downhole casing tapper for oil well

Abstract

The invention provides an oil well downhole casing tapper, and relates to the field of casing perforation. The oil well downhole casing tapper comprises a center shell, a drilling assembly, a power assembly and a sealing assembly, auxiliary covers are fixedly installed at the two ends of the center shell, circulating connecting covers are installed at the ends, away from the center shell, of the auxiliary covers in a threaded mode, the sealing assembly is installed in the auxiliary covers in a threaded mode, and the power assembly is connected with the drilling assembly through the sealing assembly. According to the downhole casing tapper, the drilling assembly and the power assembly are arranged, and constant pressure is formed inside and outside the center shell, so that transverse movement of a drill bit is not affected by water pressure in a casing with any depth, chippings produced by the drill bit are prevented from directly falling on the center shell, and compared with a hydraulic driving mode in the prior art, the drilling precision is higher, hydrostatic pressure does not need to be counteracted, and the drilling efficiency is improved. The hydraulic pressure does not need to be changed according to the pressure, the sealing assembly is arranged, sealing treatment is conducted in the closed pipe, and accurate operation in the underground casing pipe with the depth of thousands of meters can be achieved.

Description

Technical Field

[0001] The invention relates to the field of casing perforation, in particular to a casing perforator downhole in an oil well. Background Art

[0002] In the hydraulic fracturing construction process in recent years, it is necessary to first perforate the casing to form a flow drill channel between the inside and outside of the casing, which is convenient for water and sand to enter the formation during the hydraulic fracturing process, and also for oil and gas in the formation to enter the casing in the later stage, forming a convenient drill channel. Oil and gas production tools are generally placed in the casing. First, the hydraulic jet method is adopted, that is, a high-pressure pump truck is connected to the oil pipe, so that the high-speed sand-carrying water flow is sent from the ground device through the oil pipe to the designated point underground, and then ejected from the lateral hole of the sandblaster, perpendicular to the inner wall of the casing, and the casing is shot through in a few minutes.

[0003] The hydraulic jet drilling method is first used for manual operation of oil pipe dragging operation. In this method, the pressure must be released during the construction process, and the wellhead must be opened later before the oil pipe can be manually dragged. This has the disadvantages of wasting time and polluting the external environment of the well site.

[0004] In order to save time and avoid environmental pollution, the continuous tubing operation method is adopted, and the pressure operation device must be added. When the pressure operation device is used, the pressure in the well does not need to be reduced, and the wellhead does not need to be opened. The continuous tubing can be directly dragged to the next point for perforation and fracturing operations. Because the inner diameter of the continuous tubing is smaller than that of the traditional manually dragged tubing, its sandblasting perforation is limited to 4 holes 4.0mm or 6 holes 3.125mm, and the nozzle aperture is small. Compared with the traditional 8-hole 5.0mm sandblaster, the drill channel cross-sectional area formed on the casing is cumulatively small, which is not convenient for large-volume construction in the later stage, and has a greater restriction on the production capacity of later oil and gas production.

[0005] The cable pumping bridge plug method follows the continuous operation method (no need to wait for pressure reduction, no need to open the wellhead, and eliminate waste of time and pollution of the environment), and is assisted by a pressurized operation device. It uses explosives for perforation. In one construction, 20-30 holes can be made on the casing. Under the control of the pressurized operation device at the wellhead, the cable can be directly dragged to drive the explosive perforating tool to move upward, and the electric control system can be used for multi-stage perforation. It uses a pressurized operation blowout prevention device and a continuously draggable armored steel cable. It does not pollute the environment, does not waste time, and perforates in large quantities. The use efficiency is relatively high. However, the use cost of the fire attack product is relatively high, including the cost of each use and the safety management cost. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention provides a downhole casing hole opener for an oil well, which solves the problems raised in the above background technology.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions: A downhole casing hole opener for oil wells, comprising a center shell, a drilling assembly, a power assembly and a sealing assembly, both ends of the center shell are fixedly mounted with auxiliary covers, one end of the auxiliary cover away from the center shell is threadedly mounted with a circulation connection cover, the sealing assembly is threadedly mounted in the auxiliary cover, and the power assembly is connected to the drilling assembly through the sealing assembly; The drilling assembly includes a column gear, a threaded drill bit mounting frame is fixedly installed at both ends of the center hole of the column gear, and a drill bit is fixedly installed in the threaded drill bit mounting frame; it also includes a gear outer frame, the gear outer frame is an incomplete circular tube structure, and a connecting frame is fixedly installed at both ends of the gear outer frame, the connecting frame is sleeved on the corresponding threaded drill bit mounting frame, the threaded drill bit mounting frame is rotatably connected to the connecting frame, and a worm gear groove is provided on one side of the gear outer frame; The column gear is provided with a circle of circulating water channels which are equally spaced and circumferentially distributed. The circulating water channels penetrate the column gear from top to bottom. The end surface of the column gear is located on one side of the circulating water channel and is fixedly installed with a water guide plate. The water guide plate is arranged obliquely. The two groups of water guide plates on the upper and lower surfaces of the column gear are in opposite directions. When the column gear rotates, the water guide plate can guide the water flow in the circulating water channel to pass through. Two drill channels that penetrate inside and outside are provided in the middle position of the center shell, and the drill channels correspond to the two drill bits. A limiting clamp ring is fixedly installed in the middle position of the center shell, and the gear outer frame is clamped in the limiting clamp ring and connected with it for up and down sliding. A circle of circulating water inlet holes is also provided on one side of the outer surface of the center shell, and the circulating water inlet holes are connected to the center shell.

[0008] Preferably, the diameter of the drill bit channel is larger than the diameter of the drill bit, and the end of the drill bit channel corresponding to the outer wall of the center shell is a trumpet expansion structure, and a conical ring is fixedly installed on the inner wall of the center shell corresponding to the position of the drill bit channel, and the end of the conical ring away from the drill bit channel is a conical expansion structure.

[0009] Preferably, the power assembly includes a rotating shaft, and two rotating shafts are provided, respectively located on both sides of the gear outer frame, wherein a pinion is fixedly sleeved in the middle of one rotating shaft, and the pinion is meshed with the column gear, and a worm wheel is fixedly sleeved in the middle of the other rotating shaft, and the worm wheel is meshed with the worm wheel tooth groove of the gear outer frame, and when the worm wheel rotates, it can mesh with the worm wheel tooth groove to drive the gear outer frame to slide along the limiting clamp ring, and at this time the column gear does not leave the pinion gear, and the ends of the two rotating shafts are both inserted into the center shell and rotatably connected thereto; It also includes a motor, two of which are located on the left and right sides of the gear outer frame and correspond to each other axially. The output shafts of the motors are fixedly installed with transmission shafts, which pass through the sealing assembly and are rotationally connected thereto. The motor is fixed on one end of the sealing assembly, and the end of the transmission shaft away from the motor drives the rotating shaft to rotate.

[0010] Preferably, a bevel gear A is fixedly mounted on one end of the transmission shaft away from the motor, and a bevel gear B is fixedly mounted on the rotating shaft, the bevel gear A is meshed with the bevel gear B, and one of the bevel gears A corresponds to the circulating water inlet hole.

[0011] Preferably, the sealing assembly includes a closed tube, which is threadedly installed in the auxiliary cover, the motor is fixed to one end of the closed tube away from the center shell, the transmission shaft passes through the center position of the closed tube and is rotatably connected to the closed tube by a roller bearing, a water sealing ring is also installed in the closed tube, and a plane pressure bearing is installed at one end of the closed tube close to the center shell, and the plane pressure bearing is clamped by the closed tube and the bevel gear A.

[0012] Preferably, a concave platform is provided at one end of the closed tube close to the center shell, and the plane pressure bearing is located in the concave platform. The end of the bevel gear A away from the rotating shaft is a planar structure, and a convex ring is fixedly installed on the plane, and the convex ring is against the side of the plane pressure bearing away from the concave platform.

[0013] Preferably, the motor is located in a circulation connection cover, and a thread is provided on an outer wall of one end of the circulation connection cover away from the auxiliary cover.

[0014] Preferably, the limiting collar is an annular structure, and the outer wall of the column gear and the tooth groove of the worm gear both pass through the limiting collar.

[0015] Preferably, the inner wall of the limiting collar is provided with a strip-shaped groove, and the outer wall of the gear outer frame is provided with a strip-shaped protrusion, and the two cooperate with each other.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. The downhole casing hole opener of the oil well is provided with a drilling assembly and a power assembly, wherein one motor can drive the column gear through the pinion gear and then drive the drill bit to rotate, and the other motor can drive the gear outer frame through the worm gear and then drive the drill bit to move, so that the casing can be opened. Since there is water pressure in the casing to be opened, water can flow into the center shell through the drill bit channel and the circulating water inlet hole. The drill bit, the column gear, the pinion gear and the worm gear are all in water, and the pressure inside and outside the center shell is constant. Therefore, no matter in what depth of the casing, the lateral movement of the drill bit is not affected by the water pressure, and the drill bit can be moved linearly and stably. Moreover, when the column gear rotates, an undercurrent will appear inside the center shell, and the water flow will flow through the column gear to the drill bit that is drilling. The drill bit channel cooperates with the conical ring to realize directional disturbance of the water flow, so as to prevent the debris knocked down by the drill bit from falling directly on the center shell. Compared with the hydraulic drive mode of the prior art, the drilling accuracy is higher, and there is no need to offset the hydrostatic pressure, nor is there a need to convert the liquid pressure according to the pressure.

[0017] 2. The oil well downhole casing hole opener is provided with a sealing component. The water pressure in the downhole casing is mainly concentrated in the center shell and on the two bevel gears A. The bevel gears A will be pressed against the plane pressure bearing under the action of the water pressure, and then the sealing treatment is performed inside the closed tube, so that precise operation can be achieved in the downhole casing at a depth of several thousand meters. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the present invention; Figure 2 It is a cross-sectional view of the structure of the present invention; Figure 3 For the present invention Figure 2 A magnified view of the structure at center A; Figure 4 This is a structural breakdown diagram of the present invention; Figure 5 It is a structural schematic diagram of the central shell of the present invention; Figure 6 It is a structural diagram of the center shell and the punching assembly of the present invention; Figure 7 For the present invention Figure 6 A magnified view of the structure at B in the middle; Figure 8 It is a structural diagram of the punching assembly of the present invention; Fig. 9 This is a disassembled diagram of the punching assembly structure of the present invention; Fig.10 For the present invention Fig. 9 Enlarged view of the structure at C in the middle.

[0019] In the figure: 1. center shell; 2. drilling assembly; 201. column gear; 202. threaded drill bit mounting frame; 203. drill bit; 204. gear outer frame; 205. connecting frame; 206. worm gear groove; 207. circulating water channel; 208. water guide plate; 209. drill bit channel; 210. limiting clamp ring; 211. circulating water inlet hole; 212. tapered ring; 3. power assembly; 301. rotating shaft; 302. pinion; 303. worm wheel; 304. motor; 305. transmission shaft; 306. bevel gear A; 307. bevel gear B; 4. sealing assembly; 401. closing tube; 402. roller bearing; 403. plane pressure bearing; 404. convex ring; 5. auxiliary cover; 6. circulating connection cover. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0021] It should be noted that all directional indications in the embodiments of the present application are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0022] In this application, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0023] In addition, in this application, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0024] like Figure 1-10 As shown, a downhole casing hole opener for oil wells comprises a central shell 1, a drilling assembly 2, a power assembly 3 and a sealing assembly 4. Auxiliary covers 5 are fixedly installed at both ends of the central shell 1. A circulation connection cover 6 is threadedly installed at one end of the auxiliary cover 5 away from the central shell 1. The sealing assembly 4 is threadedly installed in the auxiliary cover 5. The power assembly 3 is connected to the drilling assembly 2 through the sealing assembly 4. The drilling assembly 2 includes a column gear 201, and threaded drill bit mounting frames 202 are fixedly installed at both ends of the center hole of the column gear 201, and a drill bit 203 is fixedly installed in the threaded drill bit mounting frame 202; it also includes a gear outer frame 204, the gear outer frame 204 is an incomplete circular tube structure, and connecting frames 205 are fixedly installed at both ends of the gear outer frame 204, and the connecting frame 205 is sleeved on the corresponding threaded drill bit mounting frame 202, and the threaded drill bit mounting frame 202 is rotatably connected to the connecting frame 205, and a worm gear groove 206 is provided on one side of the gear outer frame 204; A circle of circulating water channels 207 equidistantly distributed around the column gear 201 is provided. The circulating water channels 207 penetrate the column gear 201 from top to bottom. The end surface of the column gear 201 is located on one side of the circulating water channel 207 and is fixedly installed with water guide plates 208. The water guide plates 208 are tilted. The two groups of water guide plates 208 on the upper and lower surfaces of the column gear 201 are in opposite directions. When the column gear 201 rotates, the water guide plates 208 can guide the water flow in the circulating water channel 207 to pass through. Two drill channels 209 that penetrate inside and outside are provided in the middle position of the center shell 1, and the drill channels 209 correspond to the two drill bits 203. A limiting clamp ring 210 is fixedly installed in the middle position of the center shell 1. The gear outer frame 204 is stuck in the limiting clamp ring 210 and is connected with it for up and down sliding. A circle of circulating water inlet holes 211 is also provided on one side of the outer surface of the center shell 1, and the circulating water inlet holes 211 are connected to the center shell 1.

[0025] The circulation connection cover 6 at the end can be used to connect the control compartment where the battery pack and the control panel are placed, and the circulation connection cover 6 at the end can also be used to connect the bridge plug and the locator to achieve accurate positioning of the device at a determined depth in the downhole casing. The device itself is connected to a cable, which does not provide power but is mainly responsible for signal transmission. The cable can also be used to measure depth and later as a cable for going up and down the well.

[0026] The drill bit 203 can be firmly mounted on the threaded drill bit mounting frame 202, and the connection method is a bolt-tightened coupling. The connecting frame 205 matches the shape of the column gear 201. When supporting the column gear 201, it is also necessary to reduce the occupied volume inside the center shell 1. A bearing is installed at the connection position between the threaded drill bit mounting frame 202 and the connecting frame 205. Although the device operates underwater, it is still necessary to reduce the friction between the column gear 201 and the gear outer frame 204.

[0027] The circulating water channel 207 is processed on the column gear 201 in a hollowed-out form, which requires that the column gear 201 is in a vertically penetrating shape as a whole. The hollowed-out column gear 201 can reduce its own weight and can also be filled with water.

[0028] Since the center shell 1 is provided with a drill channel 209 for the drill bit 203 to extend, the interior of the center shell 1 is quickly filled with water during underwater processing to achieve constant pressure inside and outside. A circulating water inlet hole 211 is provided to ensure the constancy of the water pressure between the center shell 1 and the outside, and to avoid changes in the water pressure inside the center shell 1 when the drill bit 203 runs quickly.

[0029] The diameter of the drill channel 209 is larger than the diameter of the drill bit 203. The end of the drill channel 209 corresponding to the outer wall of the center shell 1 is a trumpet expansion structure. A conical ring 212 is fixedly installed on the inner wall of the center shell 1 corresponding to the position of the drill channel 209. The end of the conical ring 212 away from the drill channel 209 is a conical expansion structure.

[0030] The drill channel 209 is larger than the diameter of the drill bit 203, so that when the drill bit 203 extends out of the drill channel 209, the space between the drill channel 209 and the drill bit 203 can still allow water to flow through, and water flow disturbance can be achieved when the drill bit 203 rotates. When the column gear 201 rotates, the disturbed water flow can converge near the conical ring 212, and then flow from the drill channel 209 to the direction in which the drill bit 203 extends, and the other drill channel 209 will be replenished with water at any time, and the circulating water inlet hole 211 will also be replenished with water at any time, so even when the hole is opened, the water pressure will not affect the drill bit 203, and the disturbed water flow can also prevent the debris from the hole from falling directly into the center shell 1 and causing unnecessary precision impact.

[0031] The power assembly 3 includes a rotating shaft 301. There are two rotating shafts 301, which are respectively located on both sides of the gear outer frame 204. A pinion 302 is fixedly sleeved in the middle of one of the rotating shafts 301, and the pinion 302 meshes with the column gear 201. A worm wheel 303 is fixedly sleeved in the middle of the other rotating shaft 301, and the worm wheel 303 meshes with the worm wheel tooth groove 206 of the gear outer frame 204. When the worm wheel 303 rotates, it can mesh with the worm wheel tooth groove 206 to drive the gear outer frame 204 to slide along the limiting clamp ring 210. At this time, the column gear 201 does not leave the pinion 302. The ends of the two rotating shafts 301 are both inserted into the center housing 1 and are rotatably connected thereto. It also includes a motor 304. Two motors 304 are provided, which are respectively located on the left and right sides of the gear outer frame 204 and correspond to each other in the axial direction. The output shafts of the motors 304 are fixedly installed with transmission shafts 305. The transmission shafts 305 pass through the sealing assembly 4 and are rotationally connected thereto. The motor 304 is fixed on one end of the sealing assembly 4, and the end of the transmission shaft 305 away from the motor 304 drives the rotating shaft 301 to rotate.

[0032] When the pinion 302 is meshed with the column gear 201, no matter whether the column gear 201 moves up or down, the two always maintain a meshing relationship, and the power will not be interrupted. The worm wheel 303 and the worm wheel tooth groove 206 are matched to form a worm gear structure in the prior art, which can accurately feed the drill bit 203 through the motor 304.

[0033] The two motors 304 are distributed at both ends of the drill bit 203 and are coaxially arranged to maximize the use of space and achieve a better balance. One motor 304 provides a rotational force for the drill bit 203, and the other motor 304 realizes the feeding action of the drill bit 203 according to the control signal.

[0034] A bevel gear A306 is fixedly mounted on one end of the transmission shaft 305 away from the motor 304 , and a bevel gear B307 is fixedly mounted on the rotating shaft 301 . The bevel gears A306 mesh with the bevel gears B307 , and one of the bevel gears A306 corresponds to the circulating water inlet hole 211 .

[0035] Bevel gear A 306 and bevel gear B 307 are used to realize the lateral rotation force of motor 304 and transform it into the longitudinal rotation force of rotating shaft 301 .

[0036] The sealing assembly 4 includes a closed tube 401, which is threadedly installed in the auxiliary cover 5. The motor 304 is fixed to the end of the closed tube 401 away from the center shell 1. The transmission shaft 305 passes through the center position of the closed tube 401 and is rotatably connected to the closed tube 401 by a roller bearing 402. A water sealing ring is also installed in the closed tube 401. A plane pressure bearing 403 is installed at the end of the closed tube 401 close to the center shell 1, and the plane pressure bearing 403 is clamped by the closed tube 401 and the bevel gear A306.

[0037] The cooperation between the closed tube 401 and the auxiliary cover 5 is used to ensure that the motor 304 is always in a water-free environment. When the transmission shaft 305 rotates, the water sealing ring between it and the closed tube 401 can achieve a water-blocking effect. The roller bearing 402 is used to reduce the friction between the two, and a plane pressure bearing 403 is provided to receive the water pressure on the bevel gear A306 to prevent the water pressure from acting on the main shaft of the motor 304.

[0038] A concave platform is provided at one end of the closed tube 401 close to the central shell 1, and the plane pressure bearing 403 is in the concave platform. The end of the bevel gear A306 away from the rotating shaft 301 is a planar structure, and a convex ring 404 is fixedly installed on its plane, and the convex ring 404 is against the side of the plane pressure bearing 403 away from the concave platform.

[0039] The recessed platform is used to place the plane pressure bearing 403. Since the closed tube 401 is a fixed structure, the recessed platform plays the role of supporting the plane pressure bearing 403. No matter how large the water pressure is, the water pressure acting on the bevel gear A306 will be jointly acted on the closed tube 401 by the convex ring 404 and the plane pressure bearing 403, so the transmission shaft 305 can operate stably.

[0040] The motor 304 is located in the circulation connection cover 6 , and a thread is provided on the outer wall of one end of the circulation connection cover 6 away from the auxiliary cover 5 .

[0041] When underground, water will not enter the circulation connection cover 6. The outer end of the circulation connection cover 6 can also be used to connect the same equipment. Multiple sets of perforating equipment can be connected together. Just connect the power lines. Only the battery pack and the control panel need to be installed at the end to form a longer underground perforating equipment.

[0042] The limiting collar 210 is an annular structure, and the outer wall of the column gear 201 and the worm gear tooth groove 206 both pass through the limiting collar 210 .

[0043] The inner wall of the limiting collar 210 is provided with a strip-shaped groove, and the outer wall of the gear outer frame 204 is provided with a strip-shaped protrusion, and the two cooperate with each other.

[0044] The limiting collar 210 is mainly used to limit the movement of the gear outer frame 204, so as to keep the gear outer frame 204 from moving only in the axial direction relative to the drill bit 203 and avoid shaking.

[0045] When in use, multiple groups of devices are combined and connected to bridge plugs, battery packs and controllers. Magnetic positioning is used to determine the depth of the pipe when lowering the pipe. When the specified depth is reached, one of the motors 304 is turned on to operate. When the motor 304 is operating, the bevel gear A306 can be used to drive the rotating shaft 301 to rotate, so that the rotating shaft 301 drives the column gear 201 to rotate through the pinion 302, and the drill bit 203 installed on the column gear 201 can rotate in the water. When another motor 304 is operating, the other rotating shaft 301 can be driven to rotate in the same way, so that the gear outer frame 204 can be driven to move through the worm gear 303, so that the drill bit 203 can move in a rotating state. After the drill bit 203 moves out of the center shell 1, a hole can be opened in the downhole casing. The gear outer frame 204 can be controlled in reverse, and another drill bit 203 can be used to drill a hole again. One set of devices can drill two holes at a time.

[0046] When drilling, since the surface of the center shell 1 is provided with a drill channel 209 and a circulating water inlet hole 211, the water flow in the casing will enter the center shell 1, so that the pressure inside and outside the center shell 1 is constant, and the rotating shaft 301, the drill bit 203, the column gear 201, the pinion 302 and the worm gear 303 are all in the water. The water pressure is mainly concentrated on the two bevel gears A306, so the rotation and feed of the drill bit 203 are not affected by the water pressure. No matter what depth it is positioned at, the water pressure changes or whether it is stable or not, it will not affect the drilling operation.

[0047] Since the column gear 201 is treated as a circulating water channel 207, when the column gear 201 rotates, an undercurrent will appear inside the center shell 1, and the water will flow through the column gear 201 to the drill bit 203 that is drilling. The drill bit channel 209 cooperates with the conical ring 212 to achieve directional disturbance of the water flow, preventing the debris knocked down by the drill bit 203 from falling directly on the center shell 1. When drilling holes in the cast casing, there will not be much debris affecting the operation of the device.

[0048] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification.

[0049] In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0050] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A downhole casing hole opener for an oil well, characterized in that: The invention comprises a central shell (1), a drilling assembly (2), a power assembly (3) and a sealing assembly (4); auxiliary covers (5) are fixedly mounted on both ends of the central shell (1); a circulation connection cover (6) is threadedly mounted on one end of the auxiliary cover (5) away from the central shell (1); the sealing assembly (4) is threadedly mounted in the auxiliary cover (5); and the power assembly (3) is connected to the drilling assembly (2) via the sealing assembly (4); The drilling assembly (2) comprises a column gear (201), wherein threaded drill bit mounting frames (202) are fixedly mounted at both upper and lower ends of the center hole of the column gear (201), and a drill bit (203) is fixedly mounted in the threaded drill bit mounting frames (202); and further comprises a gear outer frame (204), wherein the gear outer frame (204) is an incomplete circular tube structure, wherein both upper and lower ends of the gear outer frame (204) are fixedly mounted with connecting frames (205), wherein the connecting frame (205) is sleeved on the corresponding threaded drill bit mounting frame (202), wherein the threaded drill bit mounting frame (202) is rotatably connected to the connecting frame (205), and a worm gear tooth groove (206) is provided on one side of the gear outer frame (204); The column gear (201) is provided with a circle of circulating water channels (207) which are equidistantly distributed around the column gear (201). The circulating water channels (207) penetrate the column gear (201) from top to bottom. The end surface of the column gear (201) is located on one side of the circulating water channel (207) and is fixedly mounted with a water guide plate (208). The water guide plate (208) is arranged obliquely. The two groups of water guide plates (208) on the upper and lower surfaces of the column gear (201) are in opposite directions. When the column gear (201) rotates, the water guide plate (208) can guide the water flow in the circulating water channel (207) to pass through. Two drill channels (209) are provided in the middle of the center shell (1), and the drill channels (209) correspond to the two drill bits (203). A limiting collar (210) is fixedly installed in the middle of the center shell (1). The gear outer frame (204) is clamped in the limiting collar (210) and connected to the limiting collar (210) in an upward and downward sliding manner. A circle of circulating water inlet holes (211) is also provided on one side of the outer surface of the center shell (1). The circulating water inlet holes (211) are connected to the inside of the center shell (1).

2. The oil well casing hole opener according to claim 1, characterized in that: The diameter of the drill channel (209) is greater than the diameter of the drill (203); one end of the drill channel (209) corresponding to the outer wall of the center shell (1) is a trumpet expansion structure; a conical ring (212) is fixedly installed on the inner wall of the center shell (1) at a position corresponding to the drill channel (209); one end of the conical ring (212) away from the drill channel (209) is a conical expansion structure.

3. The oil well casing hole opener according to claim 1, characterized in that: The power assembly (3) comprises a rotating shaft (301), wherein two rotating shafts (301) are provided and are respectively located on both sides of the gear outer frame (204), wherein a pinion (302) is fixedly sleeved in the middle of one rotating shaft (301), and the pinion (302) meshes with the column gear (201), and a worm wheel (303) is fixedly sleeved in the middle of the other rotating shaft (301), and the worm wheel (303) meshes with a worm wheel tooth groove (206) of the gear outer frame (204), and when the worm wheel (303) rotates, it can mesh with the worm wheel tooth groove (206) to drive the gear outer frame (204) to slide along the limiting clamping ring (210), and at this time, the column gear (201) does not leave the pinion (302), and the ends of the two rotating shafts (301) are both inserted into the center housing (1) and are rotationally connected thereto; It also includes a motor (304), wherein two motors (304) are provided, respectively located on the left and right sides of the gear outer frame (204) and axially corresponding to each other, and the output shafts of the motors (304) are fixedly mounted with a transmission shaft (305), the transmission shaft (305) passes through the sealing assembly (4) and is rotationally connected thereto, the motor (304) is fixed on one end of the sealing assembly (4), and the end of the transmission shaft (305) away from the motor (304) drives the rotating shaft (301) to rotate.

4. The oil well casing hole opener according to claim 3, characterized in that: A bevel gear A (306) is fixedly mounted on one end of the transmission shaft (305) away from the motor (304), and a bevel gear B (307) is fixedly mounted on the rotating shaft (301). The bevel gear A (306) is meshed with the bevel gear B (307), and one of the bevel gears A (306) corresponds to the circulating water inlet hole (211).

5. The downhole casing hole opener for oil wells according to claim 3, characterized in that: The sealing assembly (4) comprises a closed tube (401), the closed tube (401) being threadedly mounted in the auxiliary cover (5), the motor (304) being fixed to one end thereof away from the center housing (1), the transmission shaft (305) passing through the center position of the closed tube (401) and being rotationally connected to the closed tube (401) by a roller bearing (402), a water sealing ring being further mounted in the closed tube (401), a plane pressure bearing (403) being mounted at one end of the closed tube (401) close to the center housing (1), and the plane pressure bearing (403) being clamped by the closed tube (401) and the bevel gear A (306).

6. The oil well casing hole opener according to claim 5, characterized in that: The end of the closed tube (401) close to the center shell (1) is provided with a concave platform, and the plane pressure bearing (403) is located in the concave platform. The end of the bevel gear A (306) away from the rotating shaft (301) is a plane structure, and a convex ring (404) is fixedly installed on the plane. The convex ring (404) abuts against a surface of the plane pressure bearing (403) away from the concave platform.

7. The oil well casing hole opener according to claim 3, characterized in that: The motor (304) is located in the circulation connection cover (6), and a thread is provided on the outer wall of one end of the circulation connection cover (6) away from the auxiliary cover (5).

8. The oil well casing hole opener according to claim 1, characterized in that: The limiting collar (210) is an annular structure, and the outer wall of the column gear (201) and the worm gear tooth groove (206) both pass through the limiting collar (210).

9. The oil well casing hole opener according to claim 1, characterized in that: The inner wall of the limiting clamping ring (210) is provided with a strip-shaped groove, and the outer wall of the gear outer frame (204) is provided with a strip-shaped protrusion, and the two cooperate with each other.

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