Drill rod structure capable of preventing rock debris deposition during inclined hole drilling

Abstract

The invention discloses a drill rod structure for preventing rock debris deposition in inclined hole drilling, relates to the field of drilling of soil layers or rocks, and solves the problem of rock debris deposition in inclined hole drilling. According to the technical scheme, the drill rod structure capable of preventing rock debris deposition during inclined hole drilling comprises a drill rod, at least two mounting bases are fixedly arranged on the outer wall of the drill rod in the circumferential direction, and each mounting base is rotationally connected with a blade; an electric regulation and control device used for regulating and controlling the included angle between the length direction line of the blade and the center line of the drill rod is arranged between the blade and the drill rod or between the blade and the installation base, a storage battery is further arranged in the drill rod or the installation base or the blade, and the storage battery is electrically connected with the electric regulation and control device. During inclined hole drilling, the blades rotate along with the drill rod, the blades actively disturb drilling fluid and rock debris in an annular space formed by the outer wall of the drill rod and the hole wall of a drill hole and generate annular rotational flow, the rock debris flows along with the drilling fluid, the rock debris deposition phenomenon is effectively prevented, and the drill jamming risk during inclined hole drilling is further reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of drilling soil or rock, and particularly relates to a drill pipe structure for inclined hole drilling, which is arranged on a drill pipe and plays a role of preventing cuttings from depositing under the action of gravity. BACKGROUND

[0002] The drill pipe drives the drill bit to rotate and break the rock, and the generated cuttings are taken out of the borehole by the circulating drilling fluid. For inclined hole drilling, since the center line of the borehole is not vertical, the force balance of the cuttings transport is unbalanced, and the cuttings are prone to accumulate below the borehole, causing problems such as sticking, trajectory deviation, and increased torque. The cuttings deposition problem in inclined hole drilling is the core bottleneck restricting the drilling efficiency and safety.

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

[0004] First, additives are added to the drilling fluid to optimize the performance of the drilling fluid and improve the viscosity and suspension of the cuttings, so as to enhance the carrying capacity of the drilling fluid. However, the borehole wall is prone to leakage under the action of ground stress, which leads to the attenuation of the performance of the drilling fluid, so this method has limited effect on improving the suspension of the cuttings below the inclined hole.

[0005] Second, the pressure and flow of the drilling fluid are increased to improve the scouring of the drilling fluid on the cuttings by increasing the flow rate of the drilling fluid. However, the path of the drilling fluid is long and the resistance is large, so this method will significantly increase the energy consumption and is also prone to cause the collapse of the borehole wall.

[0006] Third, a flow guide is added to the front end (the end connected to the drill bit) of the drill pipe, and the flow direction of the fluid is guided by the flow guide. Since the flow guide is fixedly installed, the flow guide cannot adapt to the regulation and control requirements of different cuttings size gradations, and the problem of cuttings accumulation below the borehole still exists.

[0007] The above solutions to the cuttings deposition problem of inclined hole drilling do not break through the logic of "passive dependence on drilling fluid circulation" and cannot effectively solve the deposition problem of cuttings below the annular space of the drilling hole. The first method improves the suspension of the drilling fluid, and the second method improves the flow rate of the drilling fluid to achieve the migration of cuttings. None of them can actively apply an upward disturbing force to the cuttings below the drilling hole. The concentration of cuttings below the drilling hole is usually 2-3 times that above the drilling hole, and the core contradiction of gravity deposition of cuttings cannot be solved. The three methods cannot adapt to the changes in hole shape caused by changes in hole depth and geological conditions, and cannot adapt to changes in cuttings size. The control effect decreases significantly with the increase of drilling depth, and problems such as increased friction between the drill pipe and the cuttings, increased torque, increased risk of sticking, and drill pipe deviation are likely to occur. The above solutions to the cuttings deposition problem control the annular space formed by the outer wall of the drill pipe and the hole wall, and do not focus on the "drill pipe outer wall-cuttings contact area". The cuttings directly adhere to the outer wall of the drill pipe, the friction coefficient between the outer wall of the drill pipe and the hole wall is high, and the problems of sticking and drill pipe deviation have not been fundamentally alleviated. The cuttings directly adhere to the outer wall of the drill pipe, the friction coefficient between the outer wall of the drill pipe and the hole wall is high, and the problems of sticking and drill pipe deviation cannot be effectively solved. SUMMARY

[0008] The present application provides a drill pipe structure for preventing cuttings deposition in inclined hole drilling, which solves the problem of cuttings deposition in inclined hole drilling.

[0009] The technical scheme adopted by the present application is as follows: a drill pipe structure for preventing cuttings deposition in inclined hole drilling, comprising a drill pipe, at least two mounting seats are fixedly arranged on the outer wall of the drill pipe in the circumferential direction, each mounting seat is rotatably connected with a blade, the rotation axis of the blade relative to the mounting seat is arranged in the tangential direction of the circular ring of the cross section of the drill pipe, an electric control device is arranged between the blade and the drill pipe or between the blade and the mounting seat for controlling the included angle between the length direction line of the blade and the center line of the drill pipe, a battery is further arranged in the drill pipe, the mounting seat or the blade, and the battery is electrically connected with the electric control device and supplies power to the electric control device.

[0010] In order to improve the active disturbance effect of the blade on the drilling fluid and cuttings, further, the drill pipe is further provided with a liquid outlet hole, the end of the blade away from the mounting seat is provided with a spray hole, the liquid outlet hole and the spray hole are connected through a connecting pipe, or the liquid outlet hole and the spray hole are sequentially connected through the through hole in the mounting seat and the spray hole between the one end of the blade rotatably installed in the mounting seat and the end away from the mounting seat.

[0011] In order to control the flow rate of the drilling fluid in the drill pipe sprayed through the spray hole, further, the connecting pipe is provided with an electric control valve, the mounting seat is provided with an electric control valve, and the battery is electrically connected with the electric control valve and supplies power to the electric control valve.

[0012] In order to facilitate the mounting seat to be fixedly installed on the drill pipe, specifically, the mounting seat is in a tubular structure, one end of the mounting seat is inserted into the liquid outlet hole of the drill pipe and is fixed, and the other end of the mounting seat is rotationally connected to the blade.

[0013] The electric control device is used to control the included angle between the length direction line of the blade and the center line of the drill pipe, and specifically, the electric control device is an electric hydraulic telescopic device, one end of the electric hydraulic telescopic device is rotationally installed on the blade, and the other end of the electric hydraulic telescopic device is rotationally installed on the mounting seat or the outer wall of the drill pipe.

[0014] In order to facilitate the monitoring of the liquid pressure and the cuttings concentration in the annular space between the outer wall of the drill pipe and the hole wall, further, the outer wall of the drill pipe is provided with a liquid pressure sensor and / or a cuttings concentration sensor.

[0015] In order to reduce the influence of the mounting seat and the blade on the construction, further, the intersection point of the center line of the liquid outlet hole of the drill pipe and the center line of the drill pipe is taken as an end point, a ray extending in the drilling direction of the drill pipe is taken as a first ray, and a ray extending in the liquid outlet direction of the liquid outlet hole of the drill pipe is taken as a second ray, the angle formed by the first ray and the second ray is an obtuse angle; on the cross section passing through the center line of the drill pipe and the length direction line of the blade, the blade is inclined to the opposite direction of the drilling direction of the drill pipe.

[0016] In order to realize the high efficiency and low resistance of the blade rotating with the drill pipe, further, on the cross section perpendicular to the length direction line of the blade, the figure enclosed by the outer contour line of the blade is in a wing shape, the opposite edges of the wing shape are respectively a liquid-facing surface and a liquid-backing surface, the curvature radius of the liquid-facing surface is greater than that of the liquid-backing surface, and the opposite ends of the wing shape are respectively a leading edge and a trailing edge, and the leading edge and the trailing edge are both smooth curves.

[0017] In order to optimize the flow field and improve the disturbance effect of the blade on the mixed liquid (drilling fluid and cuttings), further, the blade has a continuous twist along the length direction line thereof. For example, the twist angle of the end of the blade away from the mounting seat relative to the end of the mounting seat is 15°-25°.

[0018] The beneficial effects of the present application are as follows: the outer side of the drill pipe is provided with the blade, when the inclined hole is drilled, the blade rotates with the drill pipe, the blade actively disturbs the mixed liquid (drilling fluid and cuttings) in the annular space formed between the outer wall of the drill pipe and the hole wall, the drilling fluid and the cuttings generate annular cyclone in the annular space, the cuttings below the hole are obviously subjected to upward disturbance, and the gravity deposition balance of the cuttings is broken. The rotating speed of the drill pipe and the blade is controllable, so that the gravity deposition of the cuttings is broken through the controllable cyclone, the difference between the cuttings concentrations of the lower part and the upper part of the hole is significantly reduced, the cuttings flow with the drilling fluid, and the cuttings deposition phenomenon is effectively prevented.

[0019] The electric control device can control the included angle between the blade and the drill pipe, that is, the electric control device can control the distance from the end of the blade away from the drill pipe to the center line of the drill pipe. During inclined hole drilling, the rotation speed of the drill pipe, the included angle between the blade and the drill pipe and other parameters can be dynamically controlled based on real-time data (cuttings concentration, fluid pressure, etc.) in the drill hole, so as to better adapt to the complex geological conditions (ground stress, cuttings size change) of the inclined hole. The present application also reduces the direct contact between the cuttings and the outer wall of the drill pipe, reduces the friction coefficient of the drill pipe, and reduces the risk of sticking of the inclined hole drilling. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a structural schematic diagram of an embodiment of the drill pipe structure for preventing cuttings deposition in inclined hole drilling of the present application.

[0021] Figure 2 is Figure 1 is a schematic diagram of the blade in the cross section perpendicular to the length direction line thereof.

[0022] Reference signs: drill pipe 1, center line of drill pipe 1-1, mounting seat 2, blade 3, length direction line 3-1, ejection hole 3-2, liquid-facing surface 3-3, liquid-backing surface 3-4, leading edge 3-5, trailing edge 3-6, electric control device 4, battery 5, electric control valve 6, liquid pressure sensor 7, cuttings concentration sensor 8. DETAILED DESCRIPTION

[0023] The present application will be further described below in conjunction with the drawings.

[0024] As Figure 1As shown, the drill pipe structure for preventing rock debris deposition in inclined hole drilling of the present application comprises a drill pipe 1, the cross section of the drill pipe 1 is circular ring, at least two mounting seats 2 are fixedly arranged on the outer wall of the drill pipe 1 along the circumferential direction, each mounting seat 2 is arranged at the same cross section of the drill pipe 1, that is, each mounting seat 2 is located at the same cross section of the drill pipe 1, or each mounting seat 2 is arranged at different cross sections of the drill pipe 1. When each mounting seat 2 is arranged at the same cross section of the drill pipe 1, each mounting seat 2 is preferably uniformly arranged, that is, the central angle of any two adjacent mounting seats 2 relative to the center line 1-1 of the drill pipe 1 is equal. Each mounting seat 2 is rotatably connected with 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 ring of the cross section of the drill pipe 1, and 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 pipe 1 is perpendicular but not intersected. When the blade 3 rotates relative to the mounting seat 2, the distance between the end of the blade 3 away from the mounting seat 2 and the drill pipe 1 correspondingly increases or decreases. In order to ensure the strength of the blade 3, the blade 3 is generally made of high-strength wear-resistant alloy material with hardness HRC55 or above. An electric control device 4 for adjusting the angle between the length direction line 3-1 of the blade 3 and the center line 1-1 of the drill pipe 1 is arranged between the blade 3 and the drill pipe 1 or between the blade 3 and the mounting seat 2, wherein the length direction line 3-1 of the blade 3 refers to the connecting line between the end of the blade 3 rotatably mounted on the mounting seat 2 and the end away from the mounting seat 2. A storage battery 5 is further arranged in the drill pipe 1, the mounting seat 2 or the blade 3, the storage battery 5 is electrically connected with the electric control device 4 and is used for supplying power to the electric control device 4. The storage battery 5 is generally provided with a built-in controller, the controller can receive the signal of the ground control unit and correspondingly control the electric control device 4.

[0025] During inclined hole drilling, the blade 3 and the mounting seat 2 rotate with the drill pipe 1, the blade 3 actively disturbs the mixed liquid (drilling fluid and rock debris) in the annular space formed by the outer wall of the drill pipe 1 and the hole wall, the drilling fluid and the rock debris generate annular vortex flow in the annular space, the rock debris below the hole is obviously disturbed upward, so that the settled rock debris is suspended in the drilling fluid, and the rock debris is easily discharged from the hole with the drilling fluid. Generally, the present application can control the mass concentration difference of the rock debris in the lower and upper regions of the annular space within 10%. The present application also reduces the direct contact between the rock debris and the outer wall of the drill pipe 1, which can reduce the friction coefficient of the drill pipe 1 to below 0.2, and the risk of pipe sticking is reduced by more than 50%. The present application is arranged along the center line 1-1 of the drill pipe 1, for example, the interval is 50m.

[0026] The electric control device 4 is used for adjusting 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 away from the drill pipe 1 and the center line 1-1 of the drill pipe 1. For example, the electric control device 4 is an electric hydraulic telescopic device, one end of the electric hydraulic telescopic device is rotatably mounted on the blade 3, and the other end is rotatably mounted on the mounting seat 2 or the outer wall of the drill pipe 1.Figure 1 The angle between the center line 1-1 of the drill pipe 1 and the length direction line 3-1 of the vane 3 is generally an acute angle, for example, the electric control device 4 controls the rotation of the vane 3, so that the angle between the center line 1-1 of the drill pipe 1 and the length direction line 3-1 of the vane 3 changes in the range of 15°-45°.

[0027] In order to facilitate the monitoring of the liquid pressure in the annular space between the outer wall of the drill pipe 1 and the borehole wall, the outer wall of the drill pipe 1 is provided with a liquid pressure sensor 7. The liquid pressure sensor 7 is used to monitor the drilling fluid pressure in the annular space, to judge the borehole wall stability, and to provide a basis for adjusting the jet pressure of the vane 3. For example, the liquid pressure sensor 7 is a kulite standard pressure sensor HKM-312(M). In order to facilitate the monitoring of the cuttings concentration in the annular space between the outer wall of the drill pipe 1 and the borehole wall, the outer wall of the drill pipe 1 is provided with a cuttings concentration sensor 8. The cuttings concentration sensor 8 is used to monitor the cuttings concentration, to provide data for calculating the up-down concentration ratio in the annular space. For example, the cuttings concentration sensor 8 is an L-Com5530 density sensor and an Optek AF16 sand content sensor.

[0028] In order to improve the active disturbance effect of the vane 3 on the drilling fluid and cuttings, the drill pipe 1 is also provided with a liquid outlet hole, and the end of the vane 3 away from the mounting base 2 is provided with a spray hole 3-2. The liquid outlet hole and the spray hole 3-2 are connected through a connecting pipe. During inclined hole drilling, the liquid pressure in the inner cavity of the drill pipe 1 is higher than the liquid pressure in the annular space between the outer wall of the drill pipe 1 and the borehole wall. The high-pressure drilling fluid in the inner cavity of the drill pipe 1 enters the liquid outlet hole and the connecting pipe, and is then sprayed out of the spray hole 3-2 of the vane 3, to actively disturb the drilling fluid and cuttings in the annular space. In order to adjust the flow rate of the drilling fluid in the drill pipe 1 sprayed out of the spray hole, the connecting pipe is provided with an electric control valve 6, and the battery 5 is electrically connected to the electric control valve 6 and supplies power to the electric control valve 6.

[0029] In addition, in order to avoid the exposure of the connecting pipe, referring to Figure 1 The drill pipe 1 is provided with a liquid outlet hole, and the liquid outlet hole and the spray hole 3-2 are connected in sequence through the through hole in the mounting base 2, and the spray hole 3-2 between the end of the vane 3 rotatably mounted in the mounting base 2 and the end away from the mounting base 2. The spray hole 3-2 is provided between the end of the vane 3 rotatably mounted in the mounting base 2 and the end away from the mounting base 2, as shown in Figure 1 and Figure 2The spray holes 3-2 are generally arranged along the length direction line 3-1 of the blade 3 at this time, as shown. The diameters of the spray holes 3-2 are selected according to requirements, for example, the spray holes 3-2 with a diameter of 5mm to 8mm are arranged in the blade 3. When the inclined hole drilling is performed, the high-pressure drilling fluid in the inner cavity of the drill rod 1 enters the liquid outlet hole of the drill rod 1, the through hole in the mounting seat 2, the spray hole 3-2 of the blade 3, and is sprayed out. Generally, the pressure of the drilling fluid sprayed out of the spray hole 3-2 is 0.5MPa to 3.0MPa, and the pressure can be changed according to requirements. In order to control the flow of the drilling fluid in the drill rod 1 sprayed out of the spray hole, the mounting seat 2 is provided with an electric control valve 6, and a storage battery 5 is electrically connected with the electric control valve 6 and supplies power to the electric control valve 6. The storage battery 5 is generally provided with a controller, which can receive signals of a ground control unit and control the electric control valve 6 accordingly.

[0030] The mounting seat 2 is mainly used for mounting the blade 3. In order to facilitate the mounting of the mounting seat 2 on the drill rod 1, the mounting seat 2 is in a tubular structure, one end of the mounting seat 2 is inserted into the liquid outlet hole of the drill rod 1 and is fixed, and the other end of the mounting seat 2 is rotationally connected with the blade 3. For example, one end of the mounting seat 2 is inserted into the liquid outlet hole of the drill rod 1 and is welded and fixed, while the stability and sealing between the mounting seat 2 and the liquid outlet hole of the drill rod 1 are ensured.

[0031] In order to reduce the influence of the mounting seat 2 and the blade 3 on the construction, especially the influence of the mounting seat 2 and the blade 3 on the placing of the drill rod 1 into the borehole, the mounting seat 2 is inclined to the direction opposite to the direction in which the drill rod 1 is placed into the borehole, as shown. Figure 1 When the mounting seat 2 is in a tubular structure and is fixed in the liquid outlet hole of the drill rod 1, the intersection of the center line of the liquid outlet hole of the drill rod 1 and the center line 1-1 of the drill rod 1 is taken as an end point, a ray with the drilling direction of the drill rod 1 as an extension direction is taken as a first ray, and a ray with the liquid outlet direction of the liquid outlet hole of the drill rod 1 as an extension direction is taken as a second ray, and 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 to the opposite direction of the drilling direction of the drill rod 1. The inclination direction of the blade 3 is consistent with the inclination direction of the mounting seat 2, and by controlling the blade 3 to be as close as possible to the drill rod 1 through the electric control device 4, the influence of the mounting seat 2 and the blade 3 on the placing of the drill rod 1 into the borehole can be reduced to the maximum extent.

[0032] In order to realize the high-efficiency and low-resistance rotation of the blade 3 with the drill rod 1 and ensure the disturbance effect of the blade 3 on the drilling fluid and the cuttings, the blade 2 adopts the following shape. As shown in Figure 2As shown, in the cross section perpendicular to the length direction line 3-1 of the blade 3, the outer contour line of the blade 3 encloses a wing shape, the wing shape is an asymmetric structure, and opposite edges of the wing shape are a liquid-facing surface 3-3 and a liquid-backing surface 3-4, respectively. The liquid-facing surface 3-3 faces the rotating direction of the drill pipe 1, and the liquid-backing surface 3-4 faces away from the rotating direction of the drill pipe 1. The curvature radius of the liquid-facing surface 3-3 is greater than that of the liquid-backing surface 3-4. The opposite ends of the wing shape are a leading edge 3-5 and a trailing edge 3-6, respectively. The leading edge 3-5 and the trailing edge 3-6 are both smooth curves. Compared with the trailing edge 3-6, the leading edge 3-5 is relatively smooth, and the trailing edge 3-6 is relatively sharp. The blade 3 adopts the above shape. When the blade 3 rotates with the drill pipe 1, according to Bernoulli's principle, the liquid-facing surface 3-3 and the liquid-backing surface 3-4 of the blade 3 generate a pressure difference, thereby generating a stronger and more stable annular rotational flow than a flat blade under the same energy consumption.

[0033] In order to further optimize the flow field and improve the disturbance effect of the blade 3 on the drilling fluid and cuttings, the blade 3 is continuously twisted along the length direction line 3-1. For example, the end of the blade 3 away from the mounting seat 2 is relatively rotated and mounted at the end of the mounting seat 2 at a twist angle of 15°-25°. The blade 3 adopts a twisted structure, so that the blade 3 can maintain a better attack angle at different radii, and the rotational flow velocity distribution on the entire cross section of the annular space is more uniform, avoiding local vortex 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, or the liquid outlet hole and the spray hole (3-2) are connected in sequence through the through hole in the mounting base (2) and the spray hole (3-2) between the end of the blade (3) rotatably mounted on the mounting base (2) and the end away from the mounting base (2).

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 2, characterized in that: 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).

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 outer contour line of the blade (3) forms an airfoil. The two opposite sides of the airfoil are the liquid-facing side (3-3) and the liquid-back side (3-4). The radius of curvature of the liquid-facing side (3-3) is greater than that of the liquid-back side (3-4). The two opposite ends of the airfoil are the leading edge (3-5) and the trailing edge (3-6). 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°.

Images