Deep rock mass large curvature borehole continuous coring drilling curve control method

Abstract

The present application relates to the geological drilling technology field, it discloses a kind of deep rock mass large curvature borehole continuous coring drilling curve control method, solve the problem that the drilling curve precision generated in prior art scheme is not high, accurate drilling trajectory control cannot be carried out.The present application is by collecting the real-time data such as the inclination of each trajectory segment starting point and end point, trajectory segment actual length in actual continuous coring drilling, xy In the vertical plane, the large-curvature drilling trajectory parameter equation is established according to the Bezier curve control equation; then, the theoretical arc length of the trajectory curve corresponding to the Bezier curve is calculated by derivation and modulus length calculation based on the obtained real-time data; finally, the minimum deviation between the theoretical arc length of the Bezier curve and the measured length of the trajectory segment is taken as the optimization objective, the constraint condition that the tangent directions of the two endpoints of the curve are consistent with the actual drilling direction is set, the accurate control point coordinates on the curve are obtained by iterative calculation of the optimization algorithm, and the drilling curve infinitely approximating the real drilling trajectory is finally generated.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of geological drilling, in particular to a deep rock mass large-curvature borehole continuous coring drilling curve control method. BACKGROUND

[0002] Geological drilling technology is an important means of obtaining underground physical data and exploring the earth's interior in the field of earth science. At present, geological drilling technology has made a series of new progress. For example, through the integration of drilling, slag removal, support, dust removal, ventilation, cooling, guidance, explosion prevention, and impact prevention technologies, intelligent drilling in deep well hard rock roadway is realized. In addition, the selection and configuration optimization of deep drilling key equipment have also been deeply studied to improve the drilling efficiency and meet the needs of different use conditions.

[0003] In the process of continuous coring drilling of geological bodies, real-time generation of drilling curves is of great significance. It not only helps to monitor and adjust drilling parameters in real time, improves drilling accuracy and optimizes drilling path, but also records and analyzes drilling data, improves visualization effect, and ensures the safety and reliability of drilling. However, the generation method of drilling curve commonly used in the prior art is as follows: the drilling-related data such as inclination angle and drilling distance are obtained through sensors on the drilling equipment, these data are uploaded to the ground data processing system, the relative coordinates of the drilling position are calculated, and then the adjacent coordinate points are connected by straight lines to generate the drilling curve and visualize it. The defects of this method are: the accuracy of the drilling curve is not high, especially for deep rock mass large-curvature drilling, because the curvature of the drilling trajectory changes greatly, and the drilling curve generated by the existing technical solution has no smooth transition, which cannot accurately reflect the position and direction of the drill bit, and cannot provide accurate basis for the optimization of drilling parameters, resulting in the drill bit deviating from the predetermined trajectory during drilling, which not only affects the drilling efficiency, but also may not reach the expected drilling target. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a deep rock mass large-curvature borehole continuous coring drilling curve control method to solve the problem of low accuracy of the drilling curve generated by the existing technical solution and the inability to accurately control the drilling trajectory.

[0005] The technical solution adopted by the present application to solve the above technical problem is:

[0006] The deep rock mass large-curvature borehole continuous coring drilling curve control method comprises the following steps:

[0007] S1. Obtain real-time drilling data of the drill bit:

[0008] In actual continuous coring drilling, the entire drilling path is divided into multiple drilling trajectory segments according to equal time steps. Real-time data of the current drilling trajectory segment is collected by sensors on the drill string, including:

[0009] Inclination angle at the starting point of the current drilling trajectory segment The dip angle at the end of the current drilling trajectory segment The measured length of the current drilling trajectory segment The inclination angle is the angle between the drilling direction of the drill bit and the horizontal direction;

[0010] S2. Establish the governing equations for the third-order Bézier curve:

[0011] The governing equation for the third-order Bézier curve is:

[0012] ;

[0013] in, Parameters on the Bézier curve The corresponding coordinates, Let be the coordinates of the starting point of the Bézier curve. and Here are the coordinates of the first and second control points of the Bézier curve. Let be the coordinates of the endpoint of the Bézier curve. This is a parameter, with a value range of 0 to 1. When the value is 0, it corresponds to the starting point. The coordinates, when the value is 1, correspond to the endpoint. The coordinates;

[0014] The first derivative of the governing equation is:

[0015] ;

[0016] in, Parameters on the Bézier curve The corresponding coordinate pair The first derivative;

[0017] S3. Establish the parametric equations for high-curvature drilling trajectories:

[0018] exist In the vertical plane, combining the real-time data obtained in step S1, and based on the control equations and derivatives of the third-order Bézier curve calculated in step S2, the parameters of the current drilling trajectory segment are established. Parametric equations:

[0019] ;

[0020] The The vertical plane refers to the plane formed by the horizontal direction. axis, with the depth direction perpendicular to the ground surface as the plane formed by the axis; 、 respectively the coordinates of the point on the Bezier curve corresponding to the current drilling trajectory segment at the parameter respectively the coordinates of the point on the Bezier curve corresponding to the current drilling trajectory segment at the parameter respectively the coordinates of the point on the Bezier curve corresponding to the current drilling trajectory segment at the parameter respectively the coordinates of the point on the Bezier curve corresponding to the current drilling trajectory segment at the parameter 、 respectively the coordinates of the point on the Bezier curve corresponding to the current drilling trajectory segment at the parameter respectively the coordinates of the point on the Bezier curve corresponding to the current drilling trajectory segment at the parameter respectively the coordinates of the point on the Bezier curve corresponding to the current drilling trajectory segment at the parameter respectively the coordinates of the point on the Bezier curve corresponding to the current drilling trajectory segment at the parameter 、 respectively the coordinates of the point on the Bezier curve corresponding to the current drilling trajectory segment at the parameter respectively the coordinates of the point on the Bezier curve corresponding to the current drilling trajectory segment at the parameter respectively the coordinates of the point on the Bezier curve corresponding to the current drilling trajectory segment at the parameter respectively the coordinates of the point on the Bezier curve corresponding to the current drilling trajectory segment at the parameter 、 respectively the coordinates of the point on the Bezier curve corresponding to the current drilling trajectory segment at the parameter respectively the coordinates of the point on the Bezier curve corresponding to the current drilling trajectory segment at the parameter respectively the coordinates of the point on the Bezier curve corresponding to the current drilling trajectory segment at the parameter respectively the coordinates of the point on the Bezier curve corresponding to the current drilling trajectory segment at the parameter 、 respectively the coordinates of the point on the Bezier curve corresponding to the current drilling trajectory segment at the parameter respectively the coordinates of the point on the Bezier curve corresponding to the current drilling trajectory segment at the parameter respectively the coordinates of the point on the Bezier curve corresponding to the current drilling trajectory segment at the parameter respectively the coordinates of the point on the Bezier curve corresponding to the current drilling trajectory segment at the parameter

[0021] the derivative of the parametric equation of the current drilling trajectory segment with respect to the parameter is:

[0022] ;

[0023] wherein, 、 respectively the first-order derivative of the coordinates of the point on the Bezier curve corresponding to the current drilling trajectory segment at the parameter ;

[0024] S4. Positioning the end point coordinates of the Bezier curve corresponding to the current drilling trajectory segment through an optimization algorithm:

[0025] taking the end point coordinates of the Bezier curve corresponding to the previous drilling trajectory segment as the point coordinates of the Bezier curve corresponding to the current drilling trajectory segment, calculating the point coordinates of the Bezier curve corresponding to the current drilling trajectory segment according to the coordinate conversion relationship between the point and the point;

[0026] the point and​​​ The coordinate conversion relationship of the points is: , ; wherein, is the distance between the drill bit and the controller on the drill rod;

[0027] The initial coordinates of the point corresponding to the Bezier curve of the current drilling trajectory segment are initialized, and the initial coordinates of the point corresponding to the Bezier curve of the current drilling trajectory segment are calculated according to the coordinate conversion relationship of the point and the point. The coordinate conversion relationship of the point and the point is:

[0028] The coordinate conversion relationship of the point and the point is: , ;

[0029] The initial coordinates of the point corresponding to the Bezier curve of the current drilling trajectory segment are initialized, and the initial coordinates of the point corresponding to the Bezier curve of the current drilling trajectory segment are calculated according to the coordinate conversion relationship of the point and the point. The initial coordinates of the point corresponding to the Bezier curve of the current drilling trajectory segment are initialized, and the initial coordinates of the point corresponding to the Bezier curve of the current drilling trajectory segment are calculated according to the coordinate conversion relationship of the point and the point. The initial coordinates of the point corresponding to the Bezier curve of the current drilling trajectory segment are initialized, and the initial coordinates of the point corresponding to the Bezier curve of the current drilling trajectory segment are calculated according to the coordinate conversion relationship of the point and the point. The initial coordinates of the point corresponding to the Bezier curve of the current drilling trajectory segment are initialized, and the initial coordinates of the point corresponding to the Bezier curve of the current drilling trajectory segment are calculated according to the coordinate conversion relationship of the point and the point. The initial coordinates of the point corresponding to the Bezier curve of the current drilling trajectory segment are initialized, and the initial coordinates of the point corresponding to the Bezier curve of the current drilling trajectory segment are calculated according to the coordinate conversion relationship of the point and the point. The initial coordinates of the point corresponding to the Bezier curve of the current drilling trajectory segment are initialized, and the initial coordinates of the point corresponding to the Bezier curve of the current drilling trajectory segment are calculated according to the coordinate conversion relationship of the point and the point.

[0030] S5. Calculate the drilling trajectory curve equation of the current drilling trajectory segment and draw the drilling curve:

[0031] The initial coordinates of the point corresponding to the Bezier curve of the current drilling trajectory segment are initialized, and the initial coordinates of the point corresponding to the Bezier curve of the current drilling trajectory segment are calculated according to the coordinate conversion relationship of the point and the point. The initial coordinates of the point corresponding to the Bezier curve of the current drilling trajectory segment are initialized, and the initial coordinates of the point corresponding to the Bezier curve of the current drilling trajectory segment are calculated according to the coordinate conversion relationship of the point and the point.

[0032] Further, in step S4, the optimization algorithm is BFGS algorithm, and during the iteration process, when the arc length of the Bezier curve​​​​​​​​​​​​​​​ the difference between the measured length of the current drilling trajectory segment and the calculated length of the current drilling trajectory segment is less than a set error threshold value, stopping iteration and obtaining the final coordinates of the point of the current drilling trajectory segment.

[0033] Further, in step S4, the integrand for the curve integral of the parametric equation and the derivative of the current drilling trajectory segment with respect to the parameter is: wherein represents the derivative of the parametric equation of the current drilling trajectory segment with respect to the parameter modulo.

[0034] Further, in step S4, the objective function is represented as:

[0035] ;

[0036] wherein is the measured length of the current drilling trajectory segment, is the value of the objective function.

[0037] Further, in step S4, the initial coordinates of the point of the current drilling trajectory segment corresponding to the Bezier curve are initialized, including:

[0038] ; wherein

[0039] is the x-coordinate of the initial coordinates of the point , is the y-coordinate of the initial coordinates of the point .

[0040] Further, in step S4, the constraint conditions are set, including:

[0041] ;

[0042] ;

[0043] wherein represents the tangent slope at on the Bezier curve, represents the tangent slope at on the Bezier curve.

[0044] Further, the method further includes the steps of:

[0045] ​​​​​​​S6. Adjust the drilling direction of the drill bit according to the real-time generated drilling curve, by adjusting the distance between the drill bit and the controller on the drill pipe The drilling trajectory is controlled.

[0046] Further, the adjusting the drilling direction of the drill bit according to the real-time generated drilling curve specifically comprises:

[0047] The current drilling curve is compared with the preset drilling trajectory in real time, if the current drilling curve deviates from the preset drill trajectory, the deviation direction and the adjustment amount are calculated, and the controller is sent an instruction to adjust the drilling direction of the drill bit.

[0048] The beneficial effects of the present application are:

[0049] The drilling path is divided into trajectory segments in the present application, the trajectory segments are described by using the Bezier curve, the curve bending form can be flexibly regulated and controlled, so that the drilling path with large curvature can be accurately fitted, meanwhile, the deviation between the arc length of the Bezier curve and the actual length of the drilling trajectory segment is minimized as the target by using the optimization algorithm, the constraint condition that the tangent direction at the two endpoints of the curve is consistent with the drilling direction is constructed, the accurate control point coordinates on the curve are obtained through iterative optimization, the generated drilling curve infinitely approximates the real drilling trajectory, and finally the accuracy of the generated drilling curve is improved, which provides scientific guidance for real-time monitoring and adjusting the drilling parameters, optimizing the drilling path and improving the drilling accuracy. BRIEF DESCRIPTION OF DRAWINGS

[0050] Figure 1 The flow chart of the deep rock mass large-curvature drilling continuous coring drilling curve control method in the embodiments of the present application.

[0051] Figure 2 The schematic diagram of the drilling trajectory in the vertical plane. The schematic diagram of the drilling trajectory in the vertical plane.

[0052] Figure 3 The schematic diagram of the third-order Bezier curve and its control points. DETAILED DESCRIPTION

[0053] The present application aims to provide a deep rock mass large-curvature drilling continuous coring drilling curve control method, and solve the problem that the drilling curve generated in the prior art has low accuracy and cannot accurately control the drilling trajectory. The core idea is that the entire drilling path is divided into multiple drilling trajectory segments, the advantages of good controllability and high smoothness of the Bezier curve are utilized to model and describe each trajectory segment, specifically, by collecting real-time data such as the inclination of the starting point and the ending point of each trajectory segment and the actual length of the trajectory segment in actual continuous coring drilling, the Bezier curve is constructed, the control points of the Bezier curve are calculated, and the drilling trajectory is controlled by adjusting the control points. In the vertical plane, based on the Bézier curve control equation, a parametric equation for the high-curvature drilling trajectory is established. Then, combined with the obtained real-time data, the theoretical arc length of the Bézier curve corresponding to the trajectory curve is calculated by differentiation and modulus calculation. Finally, with the minimum deviation between the theoretical arc length of the Bézier curve and the measured length of the trajectory segment as the optimization objective, and with the tangent direction at both ends of the curve being consistent with the actual drilling direction as the constraint, the accurate coordinates of the control points on the curve are obtained through iterative calculation using an optimization algorithm, and finally, a drilling curve that infinitely approximates the real drilling trajectory is generated.

[0054] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0055] This embodiment provides a method for controlling the continuous coring drilling curve in deep rock masses with large curvature. (See also...) Figure 1 It includes the following implementation process:

[0056] S1. Obtain real-time drilling data from the drill bit:

[0057] In this step, during the actual continuous coring process, the entire drilling path is divided into multiple drilling trajectory segments according to equal time steps. The purpose is to break down the complex high-curvature trajectory into smaller drilling trajectory segments so as to reduce computational complexity through segmented modeling, and at the same time facilitate the real-time adjustment and control of the drill bit based on the drilling curve.

[0058] The collected real-time drilling data includes the dip angle at the starting point of the current drilling trajectory segment. The dip angle at the end of the current drilling trajectory segment The measured length of the current drilling trajectory segment The inclination angle is the angle between the drilling direction and the horizontal direction. This data can be collected by sensors mounted on the drill string, therefore it is known data for subsequent modeling.

[0059] It is known that, because the drilling process is continuous, a series of dip angles and the actual length data of drilling trajectory segments divided according to time duration can be obtained, such as... Figure 2 As shown, in the established horizontal direction as The axis is defined by the depth direction perpendicular to the ground. shaft In the vertical plane, The point is the starting position of the borehole, serving as the origin of the coordinate system and the starting position of the first drilling trajectory segment. Its inclination angle is... Reflected in The drilling direction at the starting position of the borehole in the vertical plane, and the ending position of the first drilling trajectory segment. The angle of inclination at that point is This reflects the drilling direction at that location; the endpoint position. This is also the starting position of the second drilling trajectory segment, and the ending position of the second drilling trajectory segment is... The corresponding inclination angle is And so on, if the entire drilling trajectory has The trajectory segment, then the first... The endpoint of each trajectory segment is The corresponding inclination angle is .

[0060] S2. Establish the governing equations for the third-order Bézier curve:

[0061] In this step, the Bézier curve is a parametric curve defined by control points. It features good controllability and smoothness, making it well-suited for describing large curvature trajectory segments. Theoretically, Bézier curves of any order can be used to describe drilling trajectory segments; higher orders provide more accurate representations of the drilling path, but also increase computational complexity and resource consumption. Therefore, considering both accuracy and computational resources, this embodiment preferably uses a third-order Bézier curve. A third-order Bézier curve requires four points to draw; see [link to relevant documentation]. Figure 3 This includes the starting point, the first control point, the second control point, and the ending point. Its governing equations are:

[0062] (Equation 1)

[0063] in, Parameters on the Bézier curve The corresponding coordinates, Let be the coordinates of the starting point of the Bézier curve. and Here are the coordinates of the first and second control points of the Bézier curve. Let be the coordinates of the endpoint of the Bézier curve. This is a parameter, with a value range of 0 to 1. When the value is 0, it corresponds to the starting point. The coordinates, when the value is 1, correspond to the endpoint. The coordinates;

[0064] The first derivative of the governing equation is:

[0065] (Equation 2)

[0066] in, Parameters on the Bézier curve The corresponding coordinate pair The first derivative of the Bezier curve is used to describe the tangent direction of the point, which is the basis for establishing the constraint condition subsequently, that is, the first derivative of the Bezier curve corresponding to the drilling trajectory segment should also be continuous because the drilling direction is continuous and will not change abruptly in the actual drilling process.

[0067] S3. Establishing the parameter equation of the large-curvature drilling trajectory:

[0068] In this step, in the vertical plane, the parameter equation of the current drilling trajectory segment about the parameter is established in combination with the real-time data obtained in step S1 and the control equation and its derivative of the third-order Bezier curve calculated in step S2.

[0069] ; (Equation 3)

[0070] wherein, , are the coordinate and coordinate of the point on the Bezier curve corresponding to the current drilling trajectory segment at the parameter ; , are the coordinate and coordinate of the point on the Bezier curve corresponding to the current drilling trajectory segment at the parameter ; , are the coordinate and coordinate of the point on the Bezier curve corresponding to the current drilling trajectory segment at the parameter ; , are the coordinate and coordinate of the point on the Bezier curve corresponding to the current drilling trajectory segment at the parameter ; , are the coordinate and coordinate of the point on the Bezier curve corresponding to the current drilling trajectory segment at the parameter .

[0071] The trajectory parameter equation describes the change of the point coordinates on the drilling trajectory with the parameter , and the coordinates are decomposed into the coordinate components in the axis direction and the axis direction, so as to respectively describe the coordinate and coordinate of the point corresponding to the parameter . ​

[0072] Current drilling trajectory segment with respect to parameters The derivative of the parametric equation is:

[0073] (Equation 4)

[0074] in, , The parameters on the Bézier curve are respectively Corresponding to coordinate, coordinate pairs The first derivative. The derivative of the parametric equations provides a tool for calculating the arc length in trajectory theory, which is obtained by integrating the magnitude of the derivative.

[0075] S4. Locate the endpoint coordinates of the Bézier curve corresponding to the current drilling trajectory segment using an optimized algorithm:

[0076] In this step, to achieve an accurate representation of the trajectory segment using Bézier curves, it is necessary to determine the coordinates of four points on the Bézier curve, namely the starting point. Coordinates of the first control point Coordinates of the second control point coordinates, endpoint The coordinates; for In terms of coordinates, it is the starting point of the Bézier curve corresponding to the current trajectory segment, and also the ending point of the Bézier curve corresponding to the previous trajectory segment. Therefore, when calculating the Bézier curve corresponding to the current drilling trajectory segment, coordinates The value is known.

[0077] for In terms of coordinates, in order to bind the mathematical model of the Bézier curve with the actual physical structure of the drill string and the directional constraint depth of the drilling trajectory, and to ensure that the theoretical trajectory can accurately match the actual travel path of the drill bit, this embodiment sets... and Spacing between , The distance between the drill bit and the controller on the drill pipe is also a known value. Therefore, based on this known distance... Coordinates, known Angle of inclination at point Known Values, through coordinate transformation relationships , To calculate coordinates ,Right now, coordinates The Bézier curve corresponding to the current drilling trajectory segment is also known.

[0078] Therefore, what needs to be determined is the second control point. coordinates and endpoint Similarly, to bind the mathematical model of the Bézier curve with the actual physical structure of the drill string and the directional constraints of the drilling trajectory, ensuring that the theoretical trajectory accurately matches the actual path of the drill bit, this embodiment sets the coordinates. and Spacing between They have a coordinate transformation relationship. , ,when After the coordinates are determined, The coordinates are thus determined.

[0079] Therefore, to accurately describe the current drilling trajectory segment using a third-order Bézier curve, it is necessary to calculate an accurate... The coordinates of the point. This embodiment employs an optimization algorithm for iterative calculation, such as the BFGS (Broyden-Fletcher-Goldfarb-Shanno) algorithm. The objective function of this algorithm is the difference between the arc length of the Bézier curve representing the current drilling trajectory segment and the actual length of the current drilling trajectory segment, expressed as:

[0080] (Equation 5)

[0081] in, This represents the measured length of the current drilling trajectory segment. The objective function value;

[0082] Let be the arc length of the Bézier curve, determined by the parameters of the current drilling trajectory segment. The derivative of the parametric equation is obtained by integrating the modulus of the derivative, i.e.:

[0083] (Equation 6)

[0084] In each iteration, the BFGS method updates the approximate Hessian matrix. The gradient of the point coordinates is used to find the minimum value of the objective function. When the minimum value of the objective function is obtained, it means that the arc length of the Bézier curve is very close to the actual length of the current drilling trajectory segment. In other words, the curve representation of the drilling trajectory segment has approximated the true drilling trajectory. At this point... The coordinates of a point are its precise coordinates.

[0085] However, it is important to note that in the context of In the process of iterative optimization of the coordinates of the points, if only the difference between the arc length of the Bezier curve and the actual length of the current drilling trajectory segment is concerned, the curve direction may deviate from the actual drilling direction, and therefore, the tangent direction of the end points (the starting point and the terminal point) of the Bezier curve needs to be constrained to be consistent with the drilling direction, which is expressed by the formula:

[0086] ; (formula 7)

[0087] ; (formula 8)

[0088] wherein, represents the tangent slope at on the Bezier curve, represents the tangent slope at on the Bezier curve.

[0089] S5. Calculate the drilling trajectory curve equation of the current drilling trajectory segment and draw the drilling curve:

[0090] In this step, on the basis of obtaining the coordinates of the starting point , the coordinates of the first control point , the coordinates of the second control point , the coordinates of the terminal point of the Bezier curve corresponding to the current drilling trajectory segment through the foregoing steps, the coordinates of , the coordinates of , the coordinates of and the coordinates of are substituted into (formula 1) to obtain the drilling trajectory curve equation of the current drilling trajectory segment, and the drilling curve is drawn.

[0091] It can be understood that as the drilling process continues, the drilling curves corresponding to the continuous drilling trajectory segments can be obtained, and when the drilling ends, the complete drilling curve composed of the same number of Bezier curves connected end to end corresponding to the entire drilling trajectory is obtained.

[0092] S6. Optimize and adjust the drilling direction of the drill bit according to the real-time generated drilling curve to realize the control of the drilling trajectory:

[0093] In this step, the drilling direction of the drill bit is optimized and adjusted according to the real-time generated drilling curve, such as comparing the current drilling curve with the preset drilling trajectory in real time. If the current drilling curve deviates from the preset drilling trajectory, the deviation direction and the adjustment amount are calculated, and instructions are sent to the controller to adjust the drilling direction of the drill bit. The specific process of drilling trajectory control according to the drilling curve can be realized by using the existing technology, which will not be described here. The core of the present application lies in how to obtain a high-precision drilling curve.

[0094] Finally, it should be noted that the above embodiments are only preferred embodiments and are not intended to limit the present application. It should be pointed out that for those skilled in the art, several modifications, equivalent replacements, improvements, etc. can be made without departing from the scope of the present application and the scope of protection of the claims, and all should be included in the scope of protection of the present application.

Claims

1. A method for controlling the drilling curve of a deep rock mass large curvature coring drilling, characterized in that, The method comprises the following steps: S1. Obtaining real-time drilling data of the drill bit: In the actual continuous coring drilling process, the entire drilling path is divided into multiple drilling trajectory segments according to equal time steps, and real-time data of the current drilling trajectory segment is collected through sensors on the drilling tool, including: a pitch at a starting point of a current drilling trajectory segment a pitch at an ending point of the current drilling trajectory segment a measured length of the current drilling trajectory segment the pitch is an angle between a drilling direction of the drill bit and a horizontal direction S2. Establishing a control equation of a third-order Bezier curve: The control equation of the third-order Bezier curve is: ； wherein, is the coordinate of the starting point of the Bezier curve, is the coordinate of the corresponding point on the Bezier curve at the parameter is the coordinate of the starting point of the Bezier curve, and is the coordinate of the first control point and the second control point of the Bezier curve, is the coordinate of the end point of the Bezier curve, is the parameter, the value range is 0~1, the value 0 corresponds to the coordinate of the starting point , the value 1 corresponds to the coordinate of the end point . The first derivative of the control equation is: ； wherein, is a first derivative of the coordinate pair corresponding to the parameter on the Bezier curve; S3. Establishing a parameter equation of the large-curvature drilling trajectory: In In the vertical plane, the real-time data obtained in step S1 is combined to establish a parameter equation of the current drilling trajectory segment with respect to the parameters and its derivatives according to the control equation of the third-order Bezier curve calculated in step S2. ; The plumb surface refers to a plane formed by taking the horizontal direction as an axis and the depth direction perpendicular to the ground as an axis; , respectively, the coordinates of the corresponding points on the Bezier curve corresponding to the current drilling trajectory segment at parameters , ; , respectively, the coordinates of the corresponding points on the Bezier curve corresponding to the current drilling trajectory segment; , ; , respectively, the coordinates of the corresponding points on the Bezier curve corresponding to the current drilling trajectory segment; , ; , respectively, the coordinates of the corresponding points on the Bezier curve corresponding to the current drilling trajectory segment; , ; , respectively, the coordinates of the corresponding points on the Bezier curve corresponding to the current drilling trajectory segment; , ; Derivatives of the parametric equations of the current drilling trajectory segment with respect to the parameters are: ； in, , The parameters on the Bézier curve are respectively Corresponding to coordinate, coordinate pairs The first derivative; S4. Positioning the end point coordinates of the Bezier curve corresponding to the current drilling trajectory segment through an optimization algorithm: The endpoint coordinates of the previous drilling trajectory segment corresponding to the Bezier curve are taken as the point coordinates of the current drilling trajectory segment corresponding to the Bezier curve, and the point coordinates of the current drilling trajectory segment corresponding to the Bezier curve are calculated according to the coordinate conversion relationship between the point and the point. The Point and The coordinate conversion relationship of the point is: , ; wherein, is the distance between the drill bit and the controller on the drill rod; initialize initial coordinates of the point corresponding to the Bezier curve of the current drilling trajectory segment according to the coordinate conversion relationship between the point and the point calculate initial coordinates of the point corresponding to the Bezier curve of the current drilling trajectory segment according to the coordinate conversion relationship between the point and the point ​​​ The initialization of the Bézier curve corresponding to the current drilling trajectory segment The initial coordinates of the point include: , ; wherein is the initial coordinates of the point coordinates, is the initial coordinates of the point coordinates; The point and point coordinate conversion relationship is: , ; The point coordinates of the current drilling trajectory segment corresponding to the Bezier curve point coordinates, point coordinates, initial coordinates of the point, initial coordinates of the point as input, the length of the curve is calculated by curve integration on the parameter equation and derivative of the current drilling trajectory segment with respect to the parameter The arc length of the Bezier curve corresponding to the current drilling trajectory segment is calculated The difference between the arc length of the Bezier curve And the measured length of the current drilling trajectory segment The objective function is constructed by setting the constraint condition, and the constraint condition includes: ； ； wherein, denotes the slope of the tangent at denotes the slope of the tangent at denotes the slope of the tangent at denotes the slope of the tangent at Then the optimization algorithm is used for iterative calculation to obtain the final coordinates of the point of the Bezier curve corresponding to the current drilling trajectory segment, and based on the coordinate conversion relationship between the point and the point, the final coordinates of the point of the Bezier curve corresponding to the current drilling trajectory segment are calculated. S5. Calculating the drilling trajectory curve equation of the current drilling trajectory segment and drawing the drilling curve: The current drilling trajectory segment corresponds to the Bézier curve. Point coordinates Point coordinates The final coordinates of the point Substitute the final coordinates of the point into the control equation of the third-order Bézier curve to obtain the drilling trajectory curve equation of the current drilling trajectory segment, and then plot the drilling curve.

2. The deep rock mass large-curvature borehole continuous coring drilling curve control method according to claim 1, characterized in that, In step S4, the optimization algorithm is BFGS algorithm, in the iterative process, when the difference between the arc length of the Bezier curve and the measured length of the current drilling trajectory segment is less than the set error threshold, the iteration is stopped, and the final coordinates of the point of the current drilling trajectory segment are obtained. the measured length of the current drilling trajectory segment the measured length of the current drilling trajectory segment the measured length of the current drilling trajectory segment 3. The deep rock mass large-curvature borehole continuous coring drilling curve control method according to claim 1, characterized in that, In step S4, the parameter equation and derivative of the current drilling trajectory segment with respect to the parameter The integrand for the curve integral of the parameter equation and derivative of the current drilling trajectory segment with respect to the parameter where denotes the derivative of the parameter equation of the current drilling trajectory segment with respect to the parameter modulus.

4. The deep rock mass large-curvature borehole continuous coring drilling curve control method according to claim 3, characterized in that, In step S4, the objective function is represented as: ； wherein, is the measured length of the current drilling trajectory segment, is the objective function value.

5. The deep rock mass large-curvature borehole continuous coring drilling curve control method according to claim 1, characterized in that, The method further comprises the following steps: S6. Optimizing the drilling direction of the drill bit according to the real-time generated drilling curve, by adjusting the distance between the drill bit and the controller on the drill pipe Control of the drilling trajectory is achieved.

6. The deep rock mass large-curvature borehole continuous coring drilling curve control method according to claim 5, characterized in that, The drilling direction of the drill bit is optimized and adjusted according to the real-time generated drilling curve, specifically including: The current drilling curve is compared with the preset drilling trajectory in real time, if the current drilling curve deviates from the preset drill bit trajectory, the deviation direction and the adjustment amount are calculated, and an instruction is sent to the controller to adjust the drilling direction of the drill bit.

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