A device for flushing a wellbore mud cake

Abstract

The utility model relates to a kind of complete drilling well mud cake flushing devices, it is applied in shaft, including central tube, the outer wall bottom end of the central tube is provided with the scraping mechanism that carries out physical scraping to mud cake, and the outer wall of the central tube and located above scraping mechanism is provided with the flushing mechanism that carries out high pressure flushing to mud cake;The scraping mechanism includes rotating seat, and the rotating seat rotationally connects at the outer wall bottom end center of central tube, and the outer wall bottom end of the rotating seat is fixed with drill bit.The utility model is set by the chemical agent spraying head that can spray the chemical agent that makes mud cake soften, then by making arc plate and scraper plate rotate to carry out physical scraping to mud cake in the inner wall of shaft, finally by liquid inlet pipe to annular liquid storage pipe inside delivery clean water, so that high pressure nozzle will clean water high pressure spray to carry out flushing to mud cake in the inside of shaft, to reduce the thickness of mud cake in the inside of shaft, avoid its to the safety inside shaft cause harm.

Description

Technical Field

[0001] This utility model relates to the field of drilling equipment technology, and specifically to a drilling mud cake flushing device. Background Technology

[0002] Drilling mud cake is a dense, layered substance formed by the accumulation of solid particles from a mixture of mud, mineral powder, clay, and other materials around the well wall, in front of the drill bit, or at the bottom of the well during the drilling process.

[0003] During vertical shaft drilling, drilling mud plays a role in cooling, lubrication, and proppant carrying on the well wall, bottom of the borehole, and around the drill bit. However, under certain conditions (such as changes in mud viscosity, particle size, formation pressure, and well diameter), it can accumulate, dehydrate, and compact, forming a mud cake. A small amount of mud cake can seal the inside of the well and improve its service life. However, if the mud cake is too thick, it will block mud circulation, causing the bottom hole pressure to rise and making it difficult to control the well pressure effectively. It may also induce a blowout or well control event, especially in areas with high formation pressure or aquifers, thus posing a significant hazard. Utility Model Content

[0004] This utility model provides a drilling mud cake flushing device, which physically scrapes away the mud cake on the inner wall of the wellbore by rotating the arc plate and scraper, and flushes the mud cake inside the wellbore with high-pressure water sprayed from the high-pressure nozzle, thereby reducing the thickness of the mud cake inside the wellbore and preventing it from causing harm to the safety of the wellbore.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a drilling mud cake flushing device, which is used in the wellbore, including a central tube, a scraping mechanism for physically scraping off the mud cake is provided at the bottom of the outer wall of the central tube, and a flushing mechanism for high-pressure flushing of the mud cake is provided on the outer wall of the central tube above the scraping mechanism.

[0006] The scraping mechanism includes a rotating seat, which is rotatably connected to the center of the bottom of the outer wall of the central tube, and a drill bit is fixed to the bottom of the outer wall of the rotating seat.

[0007] Preferably, a liquid inlet protection tube is fixed at the center of the top of the outer wall of the central tube, and multiple lifting lugs are fixed at the top of the outer wall of the central tube and outside the liquid inlet protection tube.

[0008] Preferably, the multiple lifting lugs are evenly arranged in an array, and steel wire ropes are fixed to the outer walls of the lifting lugs. Multiple telescopic sleeves are fixed to the outer side of the central tube.

[0009] Preferably, the multiple telescopic sleeves are evenly arranged in a ring array, and each telescopic sleeve has a sliding rod slidably connected to its inner wall side. One end of each sliding rod inserted into the telescopic sleeve is fixed with a ring plate, and a clamping spring is fixed between the outer wall of the ring plate and the inner wall of the telescopic sleeve for clamping.

[0010] Preferably, a drive motor is installed at the bottom of the inner wall of the central tube, the output shaft of the drive motor passes through the bottom of the outer wall of the central tube and is fixedly connected to the top of the outer wall of the rotating seat, and multiple arc-shaped plates are provided on the side of the outer wall of the rotating seat.

[0011] Preferably, the multiple arc-shaped plates are evenly arranged in a ring array, the outer wall side of the rotating seat is fixed to the inner wall side of the arc-shaped plate by a fixing rod, and multiple scrapers for scraping off mud cake are fixed to the outer wall side of the arc-shaped plate.

[0012] Preferably, the flushing mechanism includes multiple annular liquid storage tubes, each annular liquid storage tube being fixed to the inner wall side of the central tube, and a high-pressure nozzle for high-pressure flushing of the mud cake being fixed to the outer wall side of the central tube at a position corresponding to the annular liquid storage tube.

[0013] The beneficial effects of this utility model are:

[0014] This invention uses an arc-shaped plate and scraper to physically scrape away the mud cake on the inner wall of the well. Clean water is then supplied to the annular storage pipe through the inlet pipe, and the high-pressure nozzle sprays the clean water at high pressure to flush the mud cake inside the well, reducing the thickness of the mud cake inside the well and preventing it from posing a safety hazard to the well. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of this utility model;

[0016] Figure 2 This utility model Figure 1 A cross-sectional view of the central tube;

[0017] Figure 3 This is a cross-sectional structural diagram of the telescopic sleeve rod of this utility model;

[0018] Figure 4 This is a schematic diagram of the arc-shaped plate and scraper in this utility model.

[0019] In the diagram: 100, wellbore; 200, central pipe; 210, inlet protection pipe; 220, lifting lug; 221, wire rope; 300, telescopic sleeve; 301, sliding rod; 302, tightening spring; 310, guide pulley; 320, inlet pipe; 330, annular storage pipe; 331, high-pressure nozzle; 340, drive motor; 350, rotating seat; 351, drill bit; 352, arc plate; 353, scraper; 360, chemical spray head. Detailed Implementation

[0020] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0021] See attached document Figures 1-4 This utility model provides a drilling mud cake flushing device, which is applied in a wellbore 100. It includes a central pipe 200, with a liquid inlet protection pipe 210 fixed at the center of the top of the outer wall of the central pipe 200. The liquid inlet protection pipe 210 is used to protect the liquid delivery pipe. Multiple lifting lugs 220 are fixed at the top of the outer wall of the central pipe 200, outside the liquid inlet protection pipe 210. These lugs 220 are evenly arranged in an array. Steel wire ropes 221 are fixed to the outer walls of each lug 220. The other end of each steel wire rope 211 can be connected to a winch, which controls the vertical movement of the central pipe 200 by winding the steel wire rope 221. Multiple telescopic sleeves 300 are fixed to the side of the outer wall of the central pipe 200. Multiple telescopic sleeves 300 are evenly arranged in a ring array. Each telescopic sleeve 300 has a sliding rod 301 slidably connected to its inner wall side. One end of the sliding rod 301 inserted into the telescopic sleeve 300 is fixed with an annular plate. A clamping spring 302 is fixed between the outer wall of the annular plate and the inner wall of the telescopic sleeve 300. The clamping spring 302 can push the sliding rod 301 outward through elastic force. The end of the sliding rod 301 away from the telescopic sleeve 300 is equipped with a guide pulley 310 through a fixing frame, so that the outer wall of the central tube 200 can move downward along the inner wall of the shaft 100. The telescopic sleeve 300 and the clamping spring 302 are provided to ensure the stability of the movement of the telescopic sleeve 300.

[0022] A scraping mechanism for physically removing mud cake is provided at the bottom of the outer wall of the central tube 200. The scraping mechanism includes a rotating seat 350, which is rotatably connected to the center of the bottom of the outer wall of the central tube 200. A drill bit 351 is fixed at the bottom of the outer wall of the rotating seat 350. When the drill bit 351 rotates, it can break through the obstructing mud. A drive motor 340 is installed at the bottom of the inner wall of the central tube 200. The drive motor 340 can be a hydraulic piston motor. A hydraulic piston motor is a device that uses the pressure of hydraulic oil to drive the movement of a piston. It is usually used to convert hydraulic energy into mechanical rotation or linear motion. Its operation is usually provided by a hydraulic pump. The oil circuit may include control elements such as throttle valves, relief valves, and directional valves to control speed, stroke, and torque. The hydraulic oil pipe of the machine 340 can be protected inside the inlet protection pipe 210. The output shaft of the drive motor 340 passes through the bottom of the outer wall of the central tube 200 and is fixedly connected to the top of the outer wall of the rotating seat 350. Multiple arc-shaped plates 352 are provided on the outer wall side of the rotating seat 350. The multiple arc-shaped plates 352 are evenly arranged in a ring array. The outer wall side of the rotating seat 350 is fixed to the inner wall side of the arc-shaped plates 352 by fixing rods. Multiple scrapers 353 for scraping mud cake are fixed on the outer wall side of the arc-shaped plates 352. The arc-shaped plates 352 and the fixing rods can be fixed by bolts or other detachable means to facilitate personnel to replace the arc-shaped plates 352. The scrapers 353 can scrape the mud cake on the inner wall of the well 100 by rotating with the scrapers 353.

[0023] A flushing mechanism for high-pressure flushing of mud cake is provided on the outer wall of the central tube 200 above the scraping mechanism. The flushing mechanism includes multiple annular liquid storage tubes 330, all of which are fixed to the inner wall side of the central tube 200. High-pressure nozzles 331 for high-pressure flushing of mud cake are fixed at the outer wall side of the central tube 200 and at positions corresponding to the annular liquid storage tubes 330. The inlet of the annular liquid storage tube 330 can be connected to the delivery pump through the inlet pipe 320, and the inlet pipe 320 can be protected by the inlet protection pipe 210. A chemical agent spray head 360 is fixed at the bottom of the outer wall of the central tube 200 above the rotating seat 350 by a bearing seat. The chemical agent spray head 360 can be connected to the chemical mixing tank through the delivery pipe. The chemical agent spray head 360 can be used to spray mud-breaking agent, soluble acid / complexing agent, or surfactant, which can improve the cleaning effect of mud cake on the inner wall of the well 100.

[0024] The usage process of this utility model is as follows: Those skilled in the art can first assemble the device according to the above description, then connect all electrical equipment to an external power supply, and control the operation of the device through an external controller. The control programs of all electrical equipment are edited by the production personnel in advance before production. This utility model does not make any technical improvements here, but only assumes that it can normally meet the needs of the operators.

[0025] The operator can install the central tube 200 inside the wellbore 100, allowing it to move up and down along the inner wall of the wellbore 100 via the telescopic sleeve 300 and guide pulley 310. The movement of the central tube 200 is controlled by unwinding the wire rope 221. After the central tube 200 is in place, the chemical mixing tank delivers the chemical solution to the chemical spray head 360 via a pump and pipe. The spray head 360 then sprays the solution onto the mud cake on the inner wall of the wellbore 100, loosening the mud cake. Hydraulic oil is then delivered to the drive motor via a hydraulic cylinder and pump. Within 340, the drive motor 340 drives the arc plate 352 and scraper 353 to rotate, so that the scraper 353 can physically scrape and crush the mud cake on the inner wall of the well 100. At the same time, flushing water is delivered to the annular liquid storage pipe 330 through the liquid inlet pipe 320, so that the annular liquid storage pipe 330 can spray clean water through the high-pressure nozzle 331 to flush the inner wall of the well 100, so that the mud cake can be further removed. The flushing force of the high-pressure nozzle 331 and the size of the scraper 353 can be set by the operator according to the thickness of the mud cake in the well 100 and the thickness to be removed.

[0026] This invention utilizes a chemical spray head to spray out a chemical agent that softens the mud cake. Then, by rotating an arc-shaped plate and scraper, the mud cake on the inner wall of the wellbore is physically scraped off. Finally, clean water is supplied to the annular storage pipe through the inlet pipe, and the high-pressure nozzle sprays the clean water at high pressure to flush the mud cake inside the wellbore. This reduces the thickness of the mud cake inside the wellbore and prevents it from posing a safety hazard to the wellbore.

[0027] The above description is merely a preferred embodiment of this utility model. Any person skilled in the art may modify this utility model or modify it into an equivalent technical solution using the technical solutions described above. Therefore, any simple modifications or equivalent substitutions made based on the technical solutions of this utility model are within the scope of protection claimed by this utility model.

Claims

1. A drilling mud cake flushing device, used in a wellbore (100), characterized in that: Includes a central tube (200), the bottom of the outer wall of the central tube (200) is provided with a scraping mechanism for physically scraping off mud cake, and the outer wall of the central tube (200) and above the scraping mechanism is provided with a rinsing mechanism for high-pressure rinsing of mud cake; The scraping mechanism includes a rotating seat (350), which is rotatably connected to the center of the bottom of the outer wall of the central tube (200), and a drill bit (351) is fixed to the bottom of the outer wall of the rotating seat (350).

2. The drilling mud cake flushing device according to claim 1, characterized in that: A liquid inlet protection tube (210) is fixed at the center of the top of the outer wall of the central tube (200), and a plurality of lifting lugs (220) are fixed at the top of the outer wall of the central tube (200) and outside the liquid inlet protection tube (210).

3. The drilling mud cake flushing device according to claim 2, characterized in that: The multiple lifting lugs (220) are evenly arranged in an array, and the outer wall of each lifting lug (220) is fixed with a steel wire rope (221). The outer wall side of the central tube (200) is fixed with multiple telescopic sleeves (300).

4. The drilling mud cake flushing device according to claim 3, characterized in that: Multiple telescopic sleeves (300) are evenly arranged in a ring array. Each telescopic sleeve (300) has a sliding rod (301) slidably connected to its inner wall side. One end of the sliding rod (301) inserted into the telescopic sleeve (300) is fixed with an annular plate. A clamping spring (302) is fixed between the outer wall of the annular plate and the inner wall of the telescopic sleeve (300).

5. The drilling mud cake flushing device according to claim 1, characterized in that: A drive motor (340) is installed at the bottom of the inner wall of the central tube (200). The output shaft of the drive motor (340) passes through the bottom of the outer wall of the central tube (200) and is fixedly connected to the top of the outer wall of the rotating seat (350). A plurality of arc plates (352) are provided on the side of the outer wall of the rotating seat (350).

6. The drilling mud cake flushing device according to claim 5, characterized in that: The multiple arc-shaped plates (352) are evenly arranged in a ring array. The outer wall side of the rotating seat (350) is fixed to the inner wall side of the arc-shaped plate (352) by a fixing rod. The outer wall side of the arc-shaped plate (352) is fixed with multiple scrapers (353) for scraping off mud cake.

7. The drilling mud cake flushing device according to claim 1, characterized in that: The flushing mechanism includes multiple annular liquid storage tubes (330), each annular liquid storage tube (330) is fixed to the inner wall side of the central tube (200), and each central tube (200) is fixed with a high-pressure nozzle (331) for high-pressure flushing of the mud cake at the outer wall side of the central tube (200) and at the position corresponding to the annular liquid storage tube (330).

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