Drill rod structure for preventing cuttings deposition in inclined hole drilling

Abstract

This invention discloses a drill rod structure for preventing cuttings deposition in inclined hole drilling, relating to drilling in soil or rock layers, and solving the problem of cuttings deposition in inclined hole drilling. The technical solution adopted by this invention is as follows: the drill rod structure for preventing cuttings deposition in inclined hole drilling includes a drill rod, with at least two mounting seats fixedly arranged circumferentially on the outer wall of the drill rod. Each mounting seat is rotatably connected to a blade. An electric control device is provided between the blade and the drill rod or between the blade and the mounting seat to adjust the angle between the length direction line of the blade and the center line of the drill rod. A battery is also provided inside the drill rod, mounting seats, or blades, and the battery is electrically connected to the electric control device. During inclined hole drilling, the blades rotate together with the drill rod, actively disturbing the drilling fluid and cuttings in the annular space formed by the outer wall of the drill rod and the borehole wall, generating an annular vortex. This causes the cuttings to flow with the drilling fluid, effectively preventing cuttings deposition and reducing the risk of stuck pipe in inclined hole drilling.

Description

Technical Field

[0001] This invention relates to the field of drilling in soil or rock, specifically a drill rod structure for inclined hole drilling, arranged on the drill rod to prevent rock cuttings from depositing under gravity. Background Technology

[0002] The drill pipe drives the drill bit to rotate and break the rock, and the resulting cuttings are carried out of the borehole by the circulating drilling fluid. For inclined hole drilling, because the centerline of the borehole is not vertical, the force imbalance during cuttings transport makes them prone to accumulating at the bottom of the borehole, causing problems such as stuck drill bit, trajectory deviation, and increased torque. The problem of cuttings deposition in inclined hole drilling is the core bottleneck restricting drilling efficiency and safety.

[0003] For the problem of cuttings deposition in inclined hole drilling, the existing solutions include the following three.

[0004] First, adding additives to the drilling fluid optimizes its performance, increases its viscosity and the suspension of cuttings, thereby enhancing its cuttings-carrying capacity. However, the borehole wall is prone to leakage under geostress, leading to a decline in drilling fluid performance. Therefore, this method has limited effect on improving the suspension of cuttings below the inclined borehole.

[0005] Secondly, increasing the pressure and flow rate of the drilling fluid can improve the flushing of rock cuttings by increasing the flow velocity of the drilling fluid. However, the drilling fluid has a long path and high resistance, which will significantly increase energy consumption and easily cause borehole collapse.

[0006] Third, a flow guide is added to the front end of the drill pipe (the end connected to the drill bit) to guide the flow of fluid. However, since the flow guide is fixed, it cannot adapt to the control requirements of different rock cutting particle size distributions, and the problem of rock cutting accumulation at the bottom of the borehole still exists.

[0007] The aforementioned solutions to the cuttings deposition problem in inclined hole drilling all fail to break free from the logic of "passively relying on drilling fluid circulation," and cannot effectively address the deposition of cuttings below the borehole annulus. The first method, by increasing the suspension of the drilling fluid, and the second method, by increasing the drilling fluid flow rate to achieve cuttings transport, neither can actively exert an upward disturbance force on the cuttings below the borehole. The cuttings concentration below the borehole is typically 2-3 times that above, failing to resolve the core contradiction of gravity-driven cuttings deposition. The fixed drilling fluid properties, circulation flow rate, and guide angle of the three methods are all unable to adapt to changes in borehole wall morphology caused by variations in borehole depth and geological conditions, nor can they adapt to changes in cuttings particle size. The control effect diminishes significantly with increasing borehole depth, easily leading to problems such as increased friction between drill pipe and cuttings, increased torque, increased risk of stuck pipe, and drill pipe deviation. The aforementioned solutions to the cuttings deposition problem regulate the annular space formed by the drill pipe outer wall and the borehole wall, but do not focus on the "drill pipe outer wall-cuttings contact area." Cuttings adhere directly to the drill pipe outer wall, resulting in a high coefficient of friction between the drill pipe outer wall and the borehole wall. This does not fundamentally alleviate the risk of stuck drill pipe and drill pipe misalignment. The direct adhesion of cuttings to the drill pipe outer wall and the high coefficient of friction between the drill pipe outer wall and the borehole wall fail to effectively solve the problems of stuck drill pipe and drill pipe misalignment. Summary of the Invention

[0008] This invention provides a drill rod structure for preventing rock cuttings deposition in inclined hole drilling, thus solving the problem of rock cuttings deposition in inclined hole drilling.

[0009] The technical solution adopted in this invention is: a drill rod structure for preventing rock cuttings deposition during inclined hole drilling, including a drill rod, at least two mounting seats are fixedly arranged circumferentially on the outer wall of the drill rod, each mounting seat is rotatably connected to a blade, the rotation axis of the blade relative to the mounting seat is arranged along the tangent direction of the annulus of the drill rod cross section, an electric control device is provided between the blade and the drill rod or between the blade and the mounting seat for adjusting the angle between the length direction line of the blade and the center line of the drill rod, and a storage battery is also provided in the drill rod, mounting seat or blade, the storage battery is electrically connected to the electric control device and supplies power to the electric control device.

[0010] To further enhance the active disturbance effect of the blade on drilling fluid and cuttings, the drill pipe is also equipped with a fluid outlet, and the end of the blade away from the mounting base is equipped with a jet outlet. The fluid outlet and the jet outlet are connected by a connecting pipe, or the fluid outlet and the jet outlet are connected by a through hole in the mounting base, and the jet outlet between the end of the blade rotated and mounted on the mounting base and the end away from the mounting base are connected in sequence.

[0011] In order to further regulate the flow rate of drilling fluid ejected from the drill pipe through the ejection orifice, the connecting pipe is equipped with an electric control valve, the mounting base is equipped with an electric control valve, and the battery is electrically connected to the electric control valve and supplies power to the electric control valve.

[0012] To facilitate the fixing of the mounting base to the drill rod, specifically: the mounting base is a tubular structure, one end of the mounting base is inserted into the fluid outlet hole of the drill rod and fixed, and the other end of the mounting base is rotatably connected to the blade.

[0013] The electric control device is used to adjust the angle between the length direction line of the blade and the center line of the drill pipe. Specifically, the electric control device is an electro-hydraulic telescopic device, one end of which is rotatably mounted on the blade, and the other end is rotatably mounted on the mounting base or the outer wall of the drill pipe.

[0014] To facilitate monitoring of the liquid pressure and cuttings concentration in the annular space between the drill pipe outer wall and the borehole wall, a liquid pressure sensor and / or cuttings concentration sensor are further provided on the drill pipe outer wall.

[0015] To further reduce the impact of the mounting base and blades on construction, the following additional measures are taken: the intersection of the centerline of the drill pipe's fluid outlet and the centerline of the drill pipe is taken as the endpoint; the ray extending in the drilling direction of the drill pipe is taken as the first ray; the ray extending in the fluid outlet direction of the drill pipe's fluid outlet is taken as the second ray; the angle formed by the first ray and the second ray is an obtuse angle; on the cross section passing through the centerline of the drill pipe and the length direction line of the blade, the blade is inclined in the opposite direction to the drilling direction of the drill pipe.

[0016] To achieve efficient and low-resistance rotation of the blade with the drill pipe, the following further design is implemented: on a cross-section perpendicular to the blade's length direction, the outer contour of the blade forms an airfoil shape, with the two opposite sides of the airfoil being the liquid-facing side and the liquid-returning side, respectively. The radius of curvature of the liquid-facing side is greater than that of the liquid-returning side, and the two opposite ends of the airfoil are the leading edge and the trailing edge, both of which are smooth curves.

[0017] To optimize the flow field and improve the blade's disturbance effect on the mixture (drilling fluid and cuttings), a further step is taken: the blade exhibits continuous torsion along its length. For example, the torsion angle between the end of the blade furthest from the mounting base and the end mounted on the mounting base is 15° to 25°.

[0018] The beneficial effects of this invention are as follows: The drill pipe has blades on its outer side. During inclined hole drilling, the blades rotate with the drill pipe, actively disturbing the mixture (drilling fluid and cuttings) within the annular space formed by the outer wall of the drill pipe and the borehole wall. This generates annular swirling flow within the annular space, significantly disturbing the cuttings below the borehole and disrupting their gravitational deposition equilibrium. The rotational speed of the drill pipe and blades is controllable, thereby breaking the gravitational deposition of cuttings through controllable swirling flow. This significantly reduces the concentration difference of cuttings between the lower and upper parts of the borehole, allowing the cuttings to flow with the drilling fluid and effectively preventing cuttings deposition.

[0019] The electric control device can adjust the angle between the blades and the drill pipe, that is, it can adjust the distance between the end of the blade furthest from the drill pipe and the centerline of the drill pipe. During inclined hole drilling, parameters such as the drill pipe rotation speed and the angle between the blades and the drill pipe can be dynamically adjusted based on real-time data (cuttings concentration, fluid pressure, etc.) within the borehole, better adapting to the complex geological conditions of inclined holes (ground stress, changes in cuttings particle size). This invention also reduces direct contact between cuttings and the outer wall of the drill pipe, lowers the friction coefficient of the drill pipe, and reduces the risk of stuck drill in inclined hole drilling. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of one embodiment of the drill rod structure for preventing rock cuttings deposition during inclined hole drilling according to the present invention.

[0021] Figure 2 yes Figure 1 A schematic diagram of the blade in a cross section perpendicular to its length direction.

[0022] Attached reference numerals: 1. Drill rod; 1-1. Centerline of drill rod; 2. Mounting seat; 3. Blade; 3-1. Length direction line; 3-2. Jet hole; 3-3. Liquid-facing surface; 3-4. Liquid-returning surface; 3-5. Leading edge; 3-6. Trailing edge; 4. Electric control device; 5. Battery; 6. Electric control valve; 7. Liquid pressure sensor; 8. Cuttings concentration sensor. Detailed Implementation

[0023] The invention will now be further described with reference to the accompanying drawings.

[0024] like Figure 1As shown, the drill rod structure for preventing rock cuttings deposition in inclined hole drilling according to the present invention includes a drill rod 1. The drill rod 1 has a circular cross-section. At least two mounting seats 2 are fixedly arranged circumferentially on the outer wall of the drill rod 1. Each mounting seat 2 is located at the same cross-section of the drill rod 1, that is, each mounting seat 2 is located at the same cross-section of the drill rod 1, or each mounting seat 2 is located at different cross-sections of the drill rod 1. When each mounting seat 2 is located at the same cross-section of the drill rod 1, the mounting seats 2 are preferably evenly distributed, that is, the central angles of any two adjacent mounting seats 2 relative to the center line 1-1 of the drill rod 1 are equal. Each mounting seat 2 is rotatably connected to a blade 3, that is, the blade 3 can rotate around the mounting seat 2. The rotation axis of the blade 3 relative to the mounting seat 2 is arranged along the tangent direction of the circular cross-section of the drill rod 1. The positional relationship between the rotation axis of the blade 3 relative to the mounting seat 2 and the center line 1-1 of the drill rod 1 is perpendicular but does not intersect. When the blade 3 rotates relative to the mounting seat 2, the distance between the end of the blade away from the mounting seat 2 and the drill rod 1 increases or decreases accordingly. To ensure the strength of blade 3, blade 3 is generally made of high-strength wear-resistant alloy material with a hardness of HRC55 or higher. An electric adjustment device 4 is provided between blade 3 and drill pipe 1, or between blade 3 and mounting base 2, to adjust the angle between the length direction line 3-1 of blade 3 and the center line 1-1 of drill pipe 1. The length direction line 3-1 of blade 3 refers to the line connecting the end of blade 3 rotatably mounted on mounting base 2 and the end furthest from mounting base 2. A battery 5 is also provided inside drill pipe 1, mounting base 2, or blade 3. The battery 5 is electrically connected to the electric adjustment device 4 and supplies power to the electric adjustment device 4. The battery 5 generally has a built-in controller, which can receive signals from the ground control unit and control the electric adjustment device 4 accordingly.

[0025] During inclined hole drilling, blade 3 and mounting base 2 rotate together with drill pipe 1. Blade 3 actively disturbs the mixture (drilling fluid and cuttings) within the annular space formed by the outer wall of drill pipe 1 and the borehole wall. The drilling fluid and cuttings generate annular swirling flow within the annular space. The cuttings below the borehole are significantly disturbed upwards, causing the settled cuttings to suspend in the drilling fluid, facilitating their discharge from the borehole with the drilling fluid. Generally, this invention can control the mass concentration difference of cuttings between the lower and upper regions of the annular space to within 10%. This invention also reduces direct contact between cuttings and the outer wall of drill pipe 1, potentially reducing the friction coefficient of drill pipe 1 to below 0.2, thus reducing the risk of stuck pipe by more than 50%. The blades are arranged at intervals along the centerline 1-1 of drill pipe 1, for example, at intervals of 50m.

[0026] The electric control device 4 is used to adjust the angle between the blade 3 and the drill pipe 1, that is, the electric control device 4 can adjust the distance between the end of the blade 3 furthest from the drill pipe 1 and the centerline 1-1 of the drill pipe 1. For example, the electric control device 4 is an electro-hydraulic telescopic device, one end of which is rotatably mounted on the blade 3, and the other end is rotatably mounted on the mounting base 2 or the outer wall of the drill pipe 1. See also Figure 1 The angle between the centerline 1-1 of the drill pipe 1 and the length direction line 3-1 of the blade 3 is generally an acute angle. For example, the electric control device 4 controls the rotation of the blade 3 so that the angle between the centerline 1-1 of the drill pipe 1 and the length direction line 3-1 of the blade 3 varies within the range of 15° to 45°.

[0027] To facilitate monitoring of the fluid pressure in the annular space between the outer wall of drill pipe 1 and the borehole wall, a fluid pressure sensor 7 is installed on the outer wall of drill pipe 1. The fluid pressure sensor 7 monitors the drilling fluid pressure within the annular space, used to determine borehole stability, and provides a basis for adjusting the jet pressure of blade 3. For example, the fluid pressure sensor 7 is a Kulite standard pressure sensor HKM-312(M). To facilitate monitoring of the cuttings concentration in the annular space between the outer wall of drill pipe 1 and the borehole wall, a cuttings concentration sensor 8 is installed on the outer wall of drill pipe 1. The cuttings concentration sensor 8 monitors the cuttings concentration, providing data for calculating the concentration ratio between the upper and lower parts of the annular space. For example, the cuttings concentration sensor 8 is an L-Com5530 density sensor and an Optek AF16 sand content sensor.

[0028] To enhance the active disturbance effect of blade 3 on drilling fluid and cuttings, drill pipe 1 is also equipped with a fluid outlet. The end of blade 3 furthest from mounting base 2 has a jet outlet 3-2, which is connected to the fluid outlet and jet outlet 3-2 via a connecting pipe. During inclined hole drilling, the hydraulic pressure inside drill pipe 1 is greater than the hydraulic pressure in the annular space between the outer wall of drill pipe 1 and the borehole wall. The high-pressure drilling fluid inside drill pipe 1 enters the fluid outlet and connecting pipe, and then is ejected from the jet outlet 3-2 of blade 3, actively disturbing the drilling fluid and cuttings in the annular space. To regulate the flow rate of drilling fluid ejected from drill pipe 1 through the jet outlet, the connecting pipe is equipped with an electric control valve 6. Battery 5 is electrically connected to and powers the electric control valve 6.

[0029] In addition, to avoid exposing the connecting pipe, see Figure 1 The drill rod 1 is provided with a liquid outlet hole. The liquid outlet hole and the ejection hole 3-2 are connected in sequence through a through hole in the mounting base 2 and the ejection hole 3-2 between one end of the blade 3 rotatably mounted on the mounting base 2 and the end away from the mounting base 2. The ejection hole 3-2 is provided between one end of the blade 3 rotatably mounted on the mounting base 2 and the end away from the mounting base 2. Figure 1 and Figure 2As shown, the ejector holes 3-2 are generally arranged along the length direction line 3-1 of the blade 3. The diameter of the ejector holes 3-2 is selected according to needs; for example, ejector holes 3-2 with a diameter of 5mm to 8mm are opened inside the blade 3. During inclined hole drilling, the high-pressure drilling fluid in the inner cavity of the drill pipe 1 enters the outlet hole of the drill pipe 1, the through hole in the mounting base 2, and the ejector holes 3-2 of the blade 3 and is ejected. Generally, the pressure of the drilling fluid ejected from the ejector holes 3-2 is 0.5MPa to 3.0MPa, and the pressure can be changed as needed. In order to regulate the flow rate of the drilling fluid ejected from the drill pipe 1 through the ejector holes, the mounting base 2 is equipped with an electric control valve 6. The battery 5 is electrically connected to the electric control valve 6 and supplies power to the electric control valve 6. The battery 5 generally has a built-in controller, which can receive signals from the ground control unit and control the electric control valve 6 accordingly.

[0030] Mounting base 2 is mainly used to install blade 3. To facilitate the fixed installation of mounting base 2 on drill rod 1, mounting base 2 has a tubular structure. One end of mounting base 2 is inserted into the liquid outlet hole of drill rod 1 and fixed, while the other end of mounting base 2 is rotatably connected to blade 3. For example, one end of mounting base 2 is inserted into the liquid outlet hole of drill rod 1 and welded to it, while ensuring the stability and sealing between mounting base 2 and the liquid outlet hole of drill rod 1.

[0031] To minimize the impact of mounting base 2 and blade 3 on construction, especially on the insertion of drill rod 1 into the borehole, mounting base 2 is tilted away from the direction in which drill rod 1 is inserted into the borehole. Figure 1 As shown. When the mounting base 2 is a tubular structure and fixed inside the fluid outlet hole of the drill rod 1, the first ray extends from the intersection of the centerline of the fluid outlet hole of the drill rod 1 and the centerline 1-1 of the drill rod 1, and the second ray extends from the direction of the drill rod 1's drilling. The angle formed by the first ray and the second ray is obtuse. On the cross-section passing through the centerline 1-1 of the drill rod 1 and the length direction line 3-1 of the blade 3, the blade 3 is inclined in the opposite direction to the drilling direction of the drill rod 1. The inclination direction of the blade 3 is consistent with the inclination direction of the mounting base 2. By controlling the end of the blade 3 away from the mounting base 2 to be as close as possible to the drill rod 1 through the electric control device 4, the influence of the mounting base 2 and the blade 3 on the insertion of the drill rod 1 into the borehole can be minimized.

[0032] To achieve efficient and low-resistance rotation of blade 3 with drill pipe 1, and to ensure the effective disturbance of drilling fluid and cuttings by blade 3, blade 3 adopts the following shape. For example... Figure 2As shown, in a cross-section perpendicular to the length line 3-1 of blade 3, the outer contour of blade 3 forms an airfoil. The airfoil is an asymmetrical structure, with its two opposite sides being the upstream side 3-3 and the downstream side 3-4. The upstream side 3-3 faces the rotation direction of drill pipe 1, while the downstream side 3-4 faces away from the rotation direction of drill pipe 1. The radius of curvature of the upstream side 3-3 is greater than that of the downstream side 3-4. The two opposite ends of the airfoil are the leading edge 3-5 and the trailing edge 3-6, both of which are smooth curves. Compared to the trailing edge 3-6, the leading edge 3-5 is relatively smooth, while the trailing edge 3-6 is relatively sharp. With the above shape, when blade 3 rotates with drill pipe 1, according to Bernoulli's principle, a pressure difference is generated between the upstream side 3-3 and the downstream side 3-4 of blade 3. This results in a stronger and more stable annular vortex than that of a flat blade, while consuming the same amount of energy.

[0033] To further optimize the flow field and improve the disturbance effect of blade 3 on drilling fluid and cuttings, blade 3 has a continuous twist along its length line 3-1. For example, the twist angle between the end of blade 3 furthest from the mounting base 2 and the end mounted on the mounting base 2 is 15° to 25°. The twisted structure of blade 3 allows it to maintain a better angle of attack at different radii, resulting in a more uniform distribution of swirling velocity across the entire cross-section of the annular space and avoiding local eddies and energy loss.

Claims

1. A drill rod structure for preventing cuttings deposition during inclined hole drilling, comprising a drill rod (1), characterized in that: At least two mounting seats (2) are fixedly installed on the outer wall of the drill rod (1) along the circumferential direction. Each mounting seat (2) is rotatably connected to a blade (3). The rotation axis of the blade (3) relative to the mounting seat (2) is arranged along the tangent direction of the annulus of the cross section of the drill rod (1). An electric control device (4) is provided between the blade (3) and the drill rod (1) or between the blade (3) and the mounting seat (2) to adjust the angle between the length direction line (3-1) of the blade (3) and the center line (1-1) of the drill rod (1). A storage battery (5) is also provided in the drill rod (1), the mounting seat (2) or the blade (3). The storage battery (5) is electrically connected to the electric control device (4) and supplies power to the electric control device (4).

2. The drill rod structure for preventing cuttings deposition during inclined hole drilling as described in claim 1, characterized in that: The drill rod (1) is also provided with a liquid outlet hole, and the blade (3) is provided with a spray hole (3-2) at the end away from the mounting base (2). The liquid outlet hole and the spray hole (3-2) are connected by a connecting pipe.

3. The drill rod structure for preventing cuttings deposition during inclined hole drilling as described in claim 2, characterized in that: The connecting pipe is equipped with an electric control valve (6), the mounting base (2) is equipped with an electric control valve (6), the battery (5) is electrically connected to the electric control valve (6) and supplies power to the electric control valve (6).

4. The drill rod structure for preventing cuttings deposition during inclined hole drilling as described in claim 1, characterized in that: The drill rod (1) is provided with a liquid outlet hole. The blade (3) is rotatably installed between one end of the mounting base (2) and the other end away from the mounting base (2) and is provided with a spray hole (3-2). The mounting base (2) is a tubular structure. One end of the mounting base (2) is inserted into the liquid outlet hole of the drill rod (1) and fixed. The other end of the mounting base (2) is rotatably connected to the blade (3). The liquid outlet hole and the spray hole (3-2) are connected through the through hole in the mounting base (2).

5. The drill rod structure for preventing cuttings deposition during inclined hole drilling as described in claim 1, characterized in that: The electric control device (4) is an electric hydraulic telescopic device. One end of the electric hydraulic telescopic device is rotatably installed on the blade (3), and the other end is rotatably installed on the mounting base (2) or the outer wall of the drill rod (1).

6. The drill rod structure for preventing cuttings deposition during inclined hole drilling as described in claim 1, characterized in that: The drill pipe (1) is equipped with a liquid pressure sensor (7) and / or a cuttings concentration sensor (8) on its outer wall.

7. The drill rod structure for preventing cuttings deposition during inclined hole drilling as described in any one of claims 1 to 6, characterized in that: The first ray is the ray extending in the direction of drilling (1) and the direction of drilling (1) with the center line of the liquid outlet hole of the drill rod (1) as the endpoint. The second ray is the ray extending in the direction of liquid outlet of the drill rod (1) with the direction of liquid outlet of the liquid outlet hole of the drill rod (1) as the extension direction. The angle formed by the first ray and the second ray is an obtuse angle. On the cross section passing through the center line (1-1) of the drill rod (1) and the length direction line (3-1) of the blade (3), the blade (3) is inclined in the opposite direction of drilling (1).

8. The drill rod structure for preventing cuttings deposition during inclined hole drilling as described in claim 7, characterized in that: On the cross section perpendicular to the length direction line (3-1) of the blade (3), the shape enclosed by the outer contour line of the blade (3) is an airfoil. The two opposite sides of the airfoil are the liquid-facing surface (3-3) and the liquid-backing surface (3-4), respectively. The radius of curvature of the liquid-facing surface (3-3) is greater than that of the liquid-backing surface (3-4). The two opposite ends of the airfoil are the leading edge (3-5) and the trailing edge (3-6), respectively. Both the leading edge (3-5) and the trailing edge (3-6) are smooth curves.

9. The drill rod structure for preventing cuttings deposition during inclined hole drilling as described in claim 8, characterized in that: The blade (3) is twisted along its length direction line (3-1).

10. The drill rod structure for preventing cuttings deposition during inclined hole drilling as described in claim 9, characterized in that: The twist angle of the blade (3) at the end away from the mounting base (2) relative to the end of the mounting base (2) is 15° to 25°.

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