A self-balancing mechanism for cleaning the inner wall of a wire-line core drill rod

Abstract

The application discloses a self-balancing mechanism for cleaning the inner wall mud of a wire-line core drill rod, which comprises a structure-integrated shell, a lower half cleaning column rotatably connected to the upper end of the structure-integrated shell, a transmission gear two coaxially and fixedly connected to the inside of the lower half cleaning column, a stator of a hollow motor fixedly connected to the inside of the structure-integrated shell, a rotor of the hollow motor fixedly connected to the outer wall of a driving gear, a transmission gear one rotatably connected to the inside of the structure-integrated shell and engaged with the driving gear and the transmission gear two, an upper half cleaning column fixedly connected to the inner wall of the driving gear after penetrating through the lower half cleaning column and the transmission gear two, a left-hand groove extending along the axial direction of the outer wall of the upper half cleaning column, a wedge-shaped metal belt connected to the left-hand groove, a forward cleaning brush for cleaning the well wall mounted on the outer side of the wedge-shaped metal belt, a right-hand groove extending along the axial direction of the outer wall of the lower half cleaning column, a wedge-shaped metal belt connected to the right-hand groove, and a reverse cleaning brush for cleaning the well wall mounted on the outer side of the wedge-shaped metal belt.

Description

Technical Field

[0001] This invention belongs to the field of deep geological exploration equipment technology, specifically a self-balancing mechanism for cleaning mud skin from the inner wall of a wireline coring drill pipe. Background Technology

[0002] In wireline coring operations, when the inner tube assembly is retrieved and lifted, mud cake or sludge often accumulates on the inner wall of the drill pipe, forming a mud column at the top. This continuously increases the lifting load on the wire rope. When this additional load exceeds the breaking strength of the wire rope, a complex accident occurs where the inner tube assembly falls. Handling such accidents is much less efficient than normal drill lifting, significantly extending non-productive time and increasing operational risks and costs. Therefore, developing efficient and reliable deep-level unblocking technology has become a critical issue that urgently needs to be addressed in current wireline coring operations.

[0003] To address this, Hunan University of Science and Technology proposed a "ropeway coring tool retrieval device with in-hole unblocking function" (patent number: 202411322436.2). This invention eliminates the need for deploying an unblocking cylinder or manual intervention, enabling multiple separations and captures directly, significantly improving retrieval reliability and work efficiency. The Beijing Institute of Exploration Engineering developed a "ropeway coring power head, structure, and control method for subsea drilling rigs" (patent number: 202010715649.7), which achieves unblocking via remote control, effectively avoiding premature and repeated unblocking issues. This invention has been verified and has achieved the expected results. While the above two methods solve the problem of wire rope breakage due to excessive upward pulling force, they do not address the cumulative tension caused by mud accumulation. Jilin University proposed a "method for cleaning the inner wall of a ropeway coring drill rod" (patent number: 202410938728.2), which uses a controllable self-suspended continuous cable pipe in conjunction with a bidirectional cleaner to remove scale. Jilin University has proposed a "self-suspended retrieval method for the inner tube assembly of a deep well wireline coring tool" (patent number: 202410938725.9). This method integrates a descaling and retrieval mechanism, using a combination of rotary spraying and scraping to remove mud skin, and employing a coaxial, counter-rotating structure to reduce disturbance. Theoretically, this patent completely solves the problem of increased cumulative lifting force on the wire rope due to mud accumulation. However, the mentioned continuous cable tube structure is complex, has a large diameter, and requires specialized cable storage equipment, making it unsuitable for existing wireline coring winches and systems. Summary of the Invention

[0004] The present invention aims to provide a self-balancing mechanism for cleaning mud skin on the inner wall of a wireline coring drill rod, so as to ensure that the mud skin cleaning work can be completed in a single retrieval process.

[0005] A self-balancing mechanism for cleaning mud from the inner wall of a wireline coring drill pipe includes an upper cleaning column, a lower cleaning column, a reverse cleaning brush, a forward cleaning brush, an integrated structural shell, a second transmission gear, a first transmission gear, a drive gear, a hollow motor, and a cable channel. The upper part of the integrated shell is rotatably connected to the lower half of the cleaning column. A second transmission gear is coaxially fixed inside the lower half of the cleaning column. The stator of the hollow motor is fixed inside the integrated shell, and the rotor of the hollow motor is fixed to the outer wall of the drive gear. A first transmission gear is rotatably connected inside the integrated shell and meshes with the drive gear and the second transmission gear. The upper half of the cleaning column passes through the lower half of the cleaning column and the second transmission gear before being fixed to the inner wall of the drive gear. The outer wall of the upper half of the cleaning column has a left-handed groove extending along its axial direction. A wedge-shaped metal strip is connected to the left-handed groove, and a forward cleaning brush for cleaning the well wall is installed on the outside of the wedge-shaped metal strip. The outer wall of the lower half of the cleaning column has a right-handed groove extending along its axial direction. A wedge-shaped metal strip is connected to the right-handed groove, and a reverse cleaning brush for cleaning the well wall is installed on the outside of the wedge-shaped metal strip. A cable channel is located at the axial center of the upper half of the cleaning column, the lower half of the cleaning column, the hollow motor, and the integrated shell, through which the armored cable passes.

[0006] The beneficial effects of this invention are: This invention provides a novel cleaning method suitable for deep well drilling environments to support wellbore cleaning operations during deep well drilling. The successful development of this device has significant theoretical and engineering value for breaking through the bottleneck of deep exploration technology, constructing a complete ultra-deep well wireline coring technology system, and carrying out advanced research on key technologies for 10,000-meter-level deep wells. Attached Figure Description

[0007] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and are used to understand the invention. They do not constitute an improper limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the structure of the present invention connected to the intelligent rope coring and salvage system equipment; Figure 2 This is a three-dimensional schematic diagram of the present invention; Figure 3 This is a cross-sectional schematic diagram of the present invention; Detailed Implementation

[0008] To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments and accompanying drawings, further clarifies the invention. Those skilled in the art should understand that the specific descriptions below are illustrative rather than restrictive and should not be construed as limiting the scope of protection of the present invention. To avoid obscuring the essence of the invention, well-known methods, processes, flows, elements, and circuits are not described in detail.

[0009] As shown in the figure, the present invention proposes a self-balancing mechanism for cleaning mud on the inner wall of a wireline coring drill pipe, comprising an upper cleaning column 201, a lower cleaning column 202, a reverse cleaning brush 203, a forward cleaning brush 204, an integrated shell 205, a second transmission gear 206, a first transmission gear 207, a drive gear 208, a hollow motor 209, and a cable channel 210. The upper end of the integrated structural housing 205 is rotatably connected to the lower half of the cleaning column 202. A second transmission gear 206 is coaxially fixed inside the lower half of the cleaning column 202. The stator of the hollow motor 209 is fixed inside the integrated structural housing 205, and the rotor of the hollow motor 209 is fixed to the outer wall of the drive gear 208. A first transmission gear 207 is rotatably connected inside the integrated structural housing 205 and meshes with the drive gear 208 and the second transmission gear 206. The upper half of the cleaning column 201 passes through the lower half of the cleaning column 202 and the second transmission gear 206, and is fixed to the inner wall of the drive gear 208. The outer wall of the upper half of the cleaning column 201 has a left-handed groove extending along its axial direction. A wedge-shaped metal strip is connected to the groove, and a forward cleaning brush 204 for cleaning the well wall is installed on the outside of the wedge-shaped metal strip. The outer wall of the lower half of the cleaning column 202 is provided with a right-handed groove extending along its axis. A wedge-shaped metal strip is connected to the right-handed groove, and a reverse cleaning brush 203 for cleaning the well wall is installed on the outside of the wedge-shaped metal strip. The left-handed groove on the outer wall of the upper half of the cleaning column 201 and the right-handed groove on the outer wall of the lower half of the cleaning column 202 have the same pitch but opposite directions of rotation. A cable channel 210 is provided at the axial position of the upper half of the cleaning column 201, the lower half of the cleaning column 202, the hollow motor 209, and the integrated structural housing 205. The outer wall of the armored cable is fixedly connected to the inner wall of the cable channel 210.

[0010] The working principle and process of this invention: When the device is in operation, it is located inside the wireline coring drill pipe. During operation, the hollow motor 209 drives the lower cleaning column 202 and the upper cleaning column 201 to rotate through a gear set. The forward cleaning brush 204 and the reverse cleaning brush 203 scrape away the deposits on the well wall. The hollow motor 209 is powered by the armored cable 101. The drive gear 208 is connected to the rotor of the hollow motor 209 by a thread, and the transmission ratio is designed to be 1:1. The first transmission gear 207 and the second transmission gear 206 are carburized and quenched gears with high tooth surface hardness. The cleaning effect is judged by monitoring the current fluctuation of the hollow motor 209. When the current value is stable within ±5% of the rated value, it indicates that the well section has been cleaned. It can adopt a "high frequency, low amplitude" working mode with a speed of 200-300 r / min and a stroke of 0.5-1.0 m to repeatedly clean stubborn scale sections. When the well temperature exceeds 350℃, it automatically switches to intermittent working mode: working for 5 minutes and stopping for 2 minutes for natural cooling. When the torque suddenly increases by more than 125% of the set value, the control system automatically reverses for 30 seconds and then rotates forward to try to unblock. If three attempts are unsuccessful, the safety clutch device is activated, with a maximum torque limit of 10 kN·m.

Claims

1. A self-balancing mechanism for cleaning mud from the inner wall of a wireline coring drill pipe, characterized in that: It includes an upper cleaning column (201), a lower cleaning column (202), a reverse cleaning brush (203), a forward cleaning brush (204), an integrated structural housing (205), a second transmission gear (206), a first transmission gear (207), a drive gear (208), a hollow motor (209), and a cable channel (210). The upper part of the integrated structural housing (205) is rotatably connected to the lower half of the cleaning column (202). The lower half of the cleaning column (202) is coaxially fixed to the inside of the transmission gear two (206). The stator of the hollow motor (209) is fixed inside the integrated structural housing (205). The rotor of the hollow motor (209) is fixed to the outer wall of the drive gear (208). The first transmission gear (207) is rotatably connected inside the integrated structural housing (205) and meshes with the drive gear (208) and the second transmission gear (206). The upper half of the cleaning column (201) passes through the lower half of the cleaning column (202) and the second transmission gear (206). 6) The upper half of the cleaning column (201) is fixed to the inner wall of the drive gear (208). The outer wall of the upper half of the cleaning column (201) is provided with a left-handed wedge-shaped metal strip. A forward cleaning brush (204) for cleaning the well wall is installed on the outside of the wedge-shaped metal strip. The outer wall of the lower half of the cleaning column (202) is provided with a right-handed wedge-shaped metal strip. A reverse cleaning brush (203) for cleaning the well wall is installed on the outside of the wedge-shaped metal strip. A cable channel (210) is provided at the axial position of the upper half of the cleaning column (201), the lower half of the cleaning column (202), the hollow motor (209), and the integrated structural shell (205). The armored cable (101) passes through the cable channel (210).

2. The self-balancing mechanism for cleaning mud from the inner wall of a wireline coring drill pipe according to claim 1, characterized in that: The outer wall of the upper cleaning column (201) is provided with a left-handed groove extending along its axial direction, and a wedge-shaped metal strip is connected to the left-handed groove. The outer wall of the lower cleaning column (202) is provided with a right-handed groove extending along its axial direction, and a wedge-shaped metal strip is connected to the right-handed groove.

Images