A crushing drilling method for complex formations

Abstract

The present invention relates to the technical field of soil layer drilling, and in particular to a crushing drilling method for complex formations. The present invention improves the efficiency and safety of the drilling process by performing formation drilling tests on a target drilling position through crushing drilling equipment, can quickly determine the density of the soil layer through the average receiving rate of sound waves at each point, and improves the efficiency of crushing drilling in complex formations. By dividing a dense drilling area and a non-dense drilling area, different drilling strategies can be adopted to ensure the drilling efficiency. The circulation flow rate of drilling fluid can be quickly determined through the cutting similarity of drilled cuttings and the change in the particle size of the cuttings, thereby reducing the occurrence of wellbore collapse. The change in the particle size of the cuttings can reduce the occurrence of wellbore blockage. By determining the circulation flow rate of drilling fluid, the wear of the drill bit can be reduced, thereby further improving the efficiency of crushing drilling.

Description

Technical Field

[0001] The invention relates to the technical field of stratum drilling, and in particular to a crushing drilling method for complex strata. Background Art

[0002] As the demand for underground resources continues to grow, the demand for efficient crushing drilling in complex formations is also increasing. Currently, crushing drilling technologies include ultrasonic drilling, hydraulic impact drilling, and rotary jet drilling. At the same time, crushing drilling technology in complex formations usually requires highly specialized technicians to operate and maintain, which increases technical difficulty and cost. The crushing drilling technology and response strategies for different formations are also different. It is of great significance to overcome the problem of low crushing drilling efficiency in complex formations.

[0003] The prior art publication number is CN116771288B, which provides a broken formation drilling equipment for geological drilling, including: a movable frame with a through hole on the frame; a ground drilling component, which is arranged on the frame; a lifting mechanism, which is arranged on the frame and drives the ground drilling component to rise and fall along the through hole; two cleaning components, which are symmetrically arranged in the through hole; the invention can realize automatic cleaning of the drill bit through the cleaning component composed of a fixed ring, a cleaning ring and a cleaning strip, without the need for subsequent manual cleaning by the drillers, greatly reducing the labor intensity of the drillers, and can prevent scaling and rust on the surface of the drill bit, helping to extend the service life of the drill bit, so that the drill bit can maintain its sharpness and avoid the drill bit from becoming blunt, thereby facilitating the broken formation drilling and improving the efficiency of geological drilling. Summary of the invention

[0004] To this end, the present invention provides a crushing drilling method for complex formations, so as to overcome the problem of low crushing drilling efficiency caused by different crushing drilling methods and coping strategies for different formations in complex formations in the prior art.

[0005] To achieve the above object, the present invention provides a fracturing drilling method for complex formations, comprising:

[0006] Installing a fixture of the crushing drilling equipment to a target drilling position of a target complex formation;

[0007] Starting the crushing drilling equipment to perform a formation drilling test on the target drilling position;

[0008] Acquiring the acoustic wave receiving rates at several points of the fixture collected during the formation drilling test;

[0009] Determine the compactness of the soil layer based on the average sound wave receiving rate at each point;

[0010] Determining a drilling adjustment method according to a determination result of the density of the soil layer;

[0011] Performing actual crushing drilling on the stratum at the target drilling position by using the corresponding drilling adjustment method;

[0012] Wherein, the drilling adjustment method includes dividing the area where the target drilling position is located into a dense drilling area and a non-dense drilling area, and replacing the fixed support rod of the fixing device corresponding to the dense drilling area with an elastic support rod;

[0013] Or, the circulation flow rate of the drilling fluid is determined jointly according to the similarity of the cutting characteristics of the drilled cuttings and the change in the particle size of the cuttings;

[0014] The cutting feature similarity is the similarity between the texture orientation of the rock cuttings before cutting and the texture orientation of the rock cuttings after cutting.

[0015] Furthermore, the process of obtaining the acoustic wave receiving rates at several points of the fixture collected by the formation drilling test includes:

[0016] Setting ultrasonic sensors at several points of the target complex formation;

[0017] Starting the crushing drilling equipment to perform a formation drilling test on the target drilling position;

[0018] Receive the sound wave signal from each ultrasonic sensor and obtain the sound wave receiving rate at each point.

[0019] Further, determining the compactness of the soil layer according to the average receiving rate of the sound waves at each point includes:

[0020] The average receiving rate of the sound waves at each point is compared with the preset receiving rate.

[0021] If the average receiving rate of the sound waves at each point is less than or equal to the preset receiving rate, the current drilling position is determined to be a non-dense drilling area;

[0022] If the average receiving rate of the sound waves at each point is greater than the preset receiving rate, it is determined that the current drilling position is a dense drilling area.

[0023] Further, if it is determined that the current drilling position is a dense drilling area, the drilling adjustment method is determined to replace the fixed support rod of the fixing device in the dense drilling area with an elastic support rod.

[0024] Furthermore, if the current drilling position is determined to be a non-dense drilling area, the drilling adjustment method is determined to jointly determine the circulation flow rate of the drilling fluid according to the cutting feature similarity of the drilled cuttings and the change in the particle size of the cuttings.

[0025] Further, the circulation flow rate of the drilling fluid is determined based on the similarity of the cutting characteristics of the drilled cuttings and the change in the particle size of the cuttings, including:

[0026] Collect the cutting characteristics and particle size of the drilled cuttings,

[0027] Calculate the similarity of cutting features of drilled cuttings;

[0028] Comparing the cutting feature similarity of the drilled rock cuttings with the preset cutting feature similarity;

[0029] If the cutting feature similarity of the drilled cuttings is greater than the preset cutting feature similarity, the circulation flow rate of the drilling fluid is maintained to continue the crushing drilling;

[0030] Calculate the change in particle size of rock cuttings;

[0031] If the cutting feature similarity of the drilled rock cuttings is less than or equal to the preset cutting feature similarity, the circulation flow rate of the drilling fluid is adjusted according to the change in the particle size of the rock cuttings.

[0032] Furthermore, the calculation formula for the cutting feature similarity of the drilled cuttings is:

[0033]

[0034] Wherein, ω is the cutting feature similarity, θ1 is the acute angle between the texture trend of the cuttings after cutting and the standard line, and θ2 is the acute angle between the texture trend of the cuttings before cutting and the standard line.

[0035] Furthermore, the adjustment range of the circulation flow rate of the drilling fluid is determined by the difference between the change in particle size of the cuttings and a preset change in particle size.

[0036] Furthermore, the change in the particle size of the rock cuttings is the ratio of the difference between the particle size of the rock cuttings after a single cycle of the circulation flow of the drilling fluid and the initial particle size of the rock cuttings to the initial particle size of the rock cuttings.

[0037] Furthermore, the circulation flow rate of the drilling fluid is the flow rate of the drilling fluid after it is pumped from the ground to the lower part of the drill bit through the drill pipe and then flows to the ground through the borehole.

[0038] Compared with the prior art, the beneficial effect of the present invention lies in that the present invention improves the efficiency and safety of the drilling process by performing formation drilling tests on the target drilling position through the crushing drilling equipment, can quickly determine the density of the soil layer through the average sound wave receiving rate at each point, and improves the efficiency of crushing drilling in complex formations, and can adopt different drilling strategies to ensure the drilling efficiency through the division of dense drilling areas and non-dense drilling areas, and can quickly determine the circulation flow rate of the drilling fluid through the cutting similarity of the drilled cuttings and the change in the particle size of the cuttings, thereby reducing the occurrence of wellbore collapse, and can reduce the occurrence of wellbore blockage through the change in the particle size of the cuttings, and can reduce the wear of the drill bit by determining the circulation flow rate of the drilling fluid, thereby further improving the efficiency of crushing drilling.

[0039] Furthermore, the present invention can quickly obtain the density of the soil layer and the stratification of the stratum through the sound wave receiving rate at each point, so as to have a more comprehensive understanding of the stratum characteristics and improve the efficiency of crushing drilling in complex strata.

[0040] Furthermore, the present invention can divide the soil layer into a dense drilling area and a non-dense drilling area by determining the density of the soil layer, and can formulate a drilling adjustment method according to the characteristics of different areas, thereby improving the crushing drilling efficiency of complex formations.

[0041] Furthermore, the present invention replaces the fixed support rods of the fixing device with elastic support rods in the dense drilling area, thereby reducing the transmission of vibration to the fixing device and the drill tool during the drilling process, and can reduce drill bit wear. At the same time, the elastic support rods can better adapt to the changes and complexity of the formation, stabilize the position and direction of the drill tool, reduce resistance and friction during the drilling process, and reduce the occurrence of drill bit sticking, thereby further improving the crushing drilling efficiency.

[0042] Furthermore, the present invention can quickly determine the formation type, rock composition and pore structure through the cutting feature similarity of the drilled cuttings and the change in the particle size of the cuttings, so as to adjust the circulation flow rate of the drilling fluid to adapt to the complex formation characteristics. The change in the particle size of the cuttings can reflect the hardness and composition of the formation to determine the change characteristics of the formation, thereby guiding the adjustment of the circulation flow rate of the drilling fluid to reduce the wear and breakage of the cuttings. At the same time, by adjusting the circulation flow rate of the drilling fluid, a certain flushing ability and suspension ability can be ensured, the occurrence of drill bit stuck can be reduced, the damage to the bottom layer and the drilling tool can be reduced, and the drilling efficiency can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a flowchart of the steps of the fracturing drilling method for complex formations according to an embodiment of the present invention;

[0044] Figure 2A flowchart of a process for obtaining the acoustic wave receiving rates at several points of the fixture collected by the formation drilling test according to an embodiment of the present invention;

[0045] Figure 3 The present invention is a flowchart for determining the density of a soil layer according to an embodiment of the present invention;

[0046] Figure 4 This is a process flow chart of jointly determining the circulation flow rate of drilling fluid according to the cutting feature similarity of drilled cuttings and the change in particle size of the cuttings according to an embodiment of the present invention. DETAILED DESCRIPTION

[0047] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0048] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0049] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside", "outside" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. This is merely for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be understood as a limitation on the present invention.

[0050] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0051] See also Figures 1 to 4 As shown, they are respectively a flowchart of the steps of a crushing drilling method for complex formations according to an embodiment of the present invention; a flowchart of the process of obtaining the acoustic wave receiving rates of several points of the fixing device collected by the formation drilling test according to an embodiment of the present invention; a flowchart of determining the density of the soil layer according to an embodiment of the present invention; a flowchart of the process of jointly determining the circulation flow rate of the drilling fluid according to the cutting feature similarity of the drilled cuttings and the change in the particle size of the cuttings according to an embodiment of the present invention; the present invention provides a crushing drilling method for complex formations, comprising:

[0052] Step S1, installing a fixing device of the crushing drilling equipment to a target drilling position of a target complex formation;

[0053] Step S2, starting the crushing drilling equipment to perform a formation drilling test on the target drilling position;

[0054] Step S3, obtaining the acoustic wave receiving rates at several points of the fixing device collected during the formation drilling test;

[0055] Step S4, determining the compactness of the soil layer according to the average receiving rate of the sound waves at each point;

[0056] Step S5, determining a drilling adjustment method according to a determination result of the density of the soil layer;

[0057] Step S6, performing actual crushing drilling on the stratum at the target drilling position according to the drilling adjustment method;

[0058] Wherein, the drilling adjustment method includes dividing the area where the target drilling position is located into a dense drilling area and a non-dense drilling area, and replacing the fixed support rod of the fixing device corresponding to the dense drilling area with an elastic support rod;

[0059] Or, the circulation flow rate of the drilling fluid is determined jointly according to the similarity of the cutting characteristics of the drilled cuttings and the change in the particle size of the cuttings;

[0060] The cutting feature similarity is the similarity between the texture orientation of the rock cuttings before cutting and the texture orientation of the rock cuttings after cutting.

[0061] Specifically, the fixing device comprises a support rod, and the support rod comprises a replaceable fixed support rod and an elastic support rod.

[0062] Specifically, the elastic support rod is a plastic elastic support rod in the prior art, including but not limited to a PVC plastic elastic support rod.

[0063] Specifically, the crushing drilling equipment is a drilling equipment in the prior art.

[0064] The present invention improves the efficiency and safety of the drilling process by performing formation drilling tests on the target drilling position through the crushing drilling equipment, can quickly determine the density of the soil layer through the average sound wave receiving rate at each point, and improves the efficiency of crushing drilling in complex formations, and can adopt different drilling strategies to ensure the drilling efficiency through the division of dense drilling areas and non-dense drilling areas, and can quickly determine the circulation flow rate of the drilling fluid through the cutting similarity of the drilled cuttings and the change in the particle size of the cuttings, thereby reducing the occurrence of wellbore collapse, and can reduce the occurrence of wellbore blockage through the change in the particle size of the cuttings, and can reduce the wear of the drill bit by determining the circulation flow rate of the drilling fluid, thereby further improving the efficiency of crushing drilling.

[0065] Specifically, ultrasonic sensors are arranged at several points of the target complex formation; the sound wave signals of each ultrasonic sensor are received and the sound wave receiving rate of each point is recorded.

[0066] Specifically, obtaining the acoustic wave receiving rates at several points of the fixture collected by the formation drilling test includes:

[0067] Step S11, ultrasonic sensors are arranged at several points of the fixing device;

[0068] Step S12, starting the crushing drilling equipment to perform a drilling test on the soil layer at the target drilling position;

[0069] Step S13, receiving the sound wave signal from each ultrasonic sensor and recording the sound wave receiving rate at each point.

[0070] The present invention can quickly obtain the density of the soil layer and the stratification of the stratum through the sound wave receiving rate of each point, so as to more comprehensively understand the stratum characteristics and improve the efficiency of crushing drilling in complex strata.

[0071] Specifically, judging the compactness of the soil layer according to the average receiving rate of the sound waves at each point includes:

[0072] The average receiving rate of the sound waves at each point is compared with the preset receiving rate.

[0073] If the average receiving rate of the sound waves at each point is less than or equal to the preset receiving rate, the current drilling position is determined to be a non-dense drilling area;

[0074] If the average receiving rate of the sound waves at each point is greater than the preset receiving rate, it is determined that the current drilling position is a dense drilling area.

[0075] In implementation, the optional range of the preset receiving rate is [800 m / s, 1500 m / s], and the preferred embodiment of the preset receiving rate is 1200 m / s.

[0076] The present invention can divide the soil layer into a dense drilling area and a non-dense drilling area by determining the density of the soil layer, and can formulate drilling adjustment methods according to the characteristics of different areas, thereby improving the crushing drilling efficiency of complex formations.

[0077] Specifically, if it is determined that the current drilling position is a dense drilling area, the fixed support rod of the fixing device in the dense drilling area is replaced with an elastic support rod.

[0078] It is understandable to those skilled in the art that the rock in the dense drilling area has high density, high strength and low porosity. This formation causes great wear on the drill bit, slows the drilling speed and is prone to drill sticking.

[0079] The present invention replaces the fixed support rods of the fixing device with elastic support rods in the dense drilling area, thereby reducing the transmission of vibration to the fixing device and the drill tool during the drilling process, and can reduce drill bit wear. At the same time, the elastic support rods can better adapt to the changes and complexity of the formation, stabilize the position and direction of the drill tool, reduce resistance and friction during the drilling process, and reduce the occurrence of drill bit sticking, thereby further improving the crushing drilling efficiency.

[0080] Specifically, if the current drilling position is determined to be a non-dense drilling area, the circulation flow rate of the drilling fluid is determined based on the similarity of the cutting characteristics of the drilled cuttings and the change in the particle size of the cuttings.

[0081] It can be understood by those skilled in the art that the rock formation in the non-dense drilling area is relatively loose, has low strength and high porosity. Such formations cause less wear on the drill bit and increase the drilling speed.

[0082] The present invention can quickly determine the formation type, rock composition and pore structure through the cutting feature similarity of the drilled cuttings and the change in the particle size of the cuttings, so as to adjust the circulation flow of the drilling fluid to adapt to the complex formation characteristics. The change in the particle size of the cuttings can reflect the hardness and composition of the formation to determine the change characteristics of the formation, thereby guiding the adjustment of the circulation flow of the drilling fluid to reduce the wear and breakage of the cuttings. At the same time, by adjusting the circulation flow of the drilling fluid, a certain flushing ability and suspension ability can be ensured, the occurrence of drill bit jamming can be reduced, the damage to the bottom layer and the drilling tool can be reduced, and the drilling efficiency is improved.

[0083] Specifically, the circulation flow rate of drilling fluid is determined based on the similarity of the cutting characteristics of the drilled cuttings and the change in particle size, including:

[0084] Collect the cutting characteristics and particle size of the drilled cuttings,

[0085] Calculate the similarity of cutting features of drilled cuttings;

[0086] Comparing the cutting feature similarity of the drilled rock cuttings with the preset cutting feature similarity;

[0087] If the cutting feature similarity of the drilled cuttings is greater than the preset cutting feature similarity, the circulation flow rate of the drilling fluid is maintained to continue the crushing drilling;

[0088] Calculate the change in particle size of the cuttings;

[0089] If the cutting feature similarity of the drilled rock cuttings is less than or equal to the preset cutting feature similarity, the circulation flow rate of the drilling fluid is adjusted according to the change in the particle size of the rock cuttings.

[0090] In the implementation, the preset cutting feature similarity is 0.95.

[0091] Specifically, the calculation formula for the cutting feature similarity of the drilled cuttings is:

[0092]

[0093] Among them, ω is the cutting feature similarity, θ1 is the acute angle between the texture trend of the cuttings after cutting and the standard line, and θ2 is the acute angle between the texture trend of the cuttings before cutting and the standard line.

[0094] In implementation, the standard line of drilled cuttings is a standard line that meets a preset benchmark and is obtained through data modeling analysis of historical data within three months.

[0095] Those skilled in the art can understand that if the two angles of the texture direction of the rock chips after cutting are very close to those of the texture direction of the rock chips before cutting, the cosine value is close to 1, indicating that the texture direction similarity is high; if the two angles of the texture direction of the rock chips after cutting are greatly different from those of the texture direction of the rock chips before cutting, the cosine value is close to 0, indicating that the texture direction similarity is low.

[0096] Specifically, the adjustment range of the circulation flow rate of the drilling fluid is determined by the difference between the change in particle size of the cuttings and the preset change in particle size.

[0097] If the difference between the change in particle size of the cuttings and the preset change in particle size is less than or equal to the preset first particle size change difference, the circulation flow rate of the drilling fluid is adjusted using the first circulation flow rate adjustment coefficient α1;

[0098] If the difference between the change in particle size of the cuttings and the preset particle size change is greater than the preset first particle size change difference and less than or equal to the preset second particle size change difference, the second circulation flow rate adjustment coefficient α2 is used to adjust the circulation flow rate of the drilling fluid;

[0099] If the difference between the change in particle size of the cuttings and the preset change in particle size is greater than the preset second particle size change difference, the third circulation flow rate adjustment coefficient α3 is used to adjust the circulation flow rate of the drilling fluid.

[0100] In implementation, the first particle size change difference is preset to be 5%, the second particle size change difference is preset to be 10%, and the adjustment formula for the circulation flow of the drilling fluid is: , where μ is the circulation flow rate of the drilling fluid after adjustment, μ0 is the circulation flow rate of the drilling fluid before adjustment, which is 12 cubic meters in the embodiment, αn is the nth circulation flow adjustment coefficient, n=1, 2, 3, α1=0.92; α2=0.86; α3=0.78; If the difference between the change in particle size of the cuttings and the preset change in particle size is 6%, the circulation flow rate of the drilling fluid after adjustment is =12×(1+0.86) / 2=11.16 cubic meters, that is, the circulation flow rate of drilling fluid is adjusted from 12 cubic meters to 11.16 cubic meters.

[0101] Specifically, the change in the particle size of the rock cuttings is the ratio of the difference between the particle size of the rock cuttings after a single cycle of the circulation flow of the drilling fluid and the initial particle size of the rock cuttings to the initial particle size of the rock cuttings.

[0102] In practice, a single cycle is 5 minutes and the particle size of the initial rock cuttings is 20 mm.

[0103] It can be understood by those skilled in the art that the change in the particle size of the rock cuttings calculates the percentage change of the final particle size relative to the initial particle size. If the calculated result is a positive value, it means that the particle size of the rock cuttings has increased; if the calculated result is a negative value, it means that the particle size of the rock cuttings has decreased; if the calculated result is zero, it means that the particle size of the rock cuttings remains unchanged.

[0104] Specifically, the circulation flow rate of the drilling fluid is the flow rate of the drilling fluid after it is pumped from the ground to the lower part of the drill bit through the drill pipe and then flows back to the ground through the borehole.

[0105] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A crushing drilling method for complex formations, characterized in that: include: Installing a fixture of the crushing drilling equipment to a target drilling position of a target complex formation; Starting the crushing drilling equipment to perform a formation drilling test on the target drilling position; Acquiring the acoustic wave receiving rates at several points of the fixture collected during the formation drilling test; Determine the compactness of the soil layer according to the average receiving rate of the sound waves at the plurality of points; The average receiving rate of the sound waves at the plurality of points is compared with the preset receiving rate. If the average receiving rate of the sound waves at the plurality of points is less than or equal to the preset receiving rate, the current drilling position is determined to be a non-dense drilling area; If the average receiving rate of the sound waves at the plurality of points is greater than the preset receiving rate, the current drilling position is determined to be a dense drilling area; Determining a drilling adjustment method according to a determination result of the density of the soil layer; Performing actual crushing drilling on the stratum at the target drilling position by using the corresponding drilling adjustment method; Wherein, the drilling adjustment method includes dividing the area where the target drilling position is located into a dense drilling area and a non-dense drilling area, and replacing the fixed support rod of the fixing device corresponding to the dense drilling area with an elastic support rod; The circulation flow rate of the drilling fluid is determined based on the similarity of the cutting characteristics of the drilled cuttings and the change in particle size; Collect the cutting characteristics and particle size of the drilled cuttings, Calculate the similarity of cutting features of drilled cuttings; Comparing the cutting feature similarity of the drilled rock cuttings with the preset cutting feature similarity; If the cutting feature similarity of the drilled cuttings is greater than the preset cutting feature similarity, the circulation flow rate of the drilling fluid is maintained to continue the crushing drilling; Calculate the change in particle size of rock cuttings; If the cutting feature similarity of the drilled cuttings is less than or equal to the preset cutting feature similarity, the circulation flow rate of the drilling fluid is adjusted according to the change in the particle size of the cuttings; If the difference between the change in particle size of the cuttings and the preset change in particle size is less than or equal to the preset first particle size change difference, the circulation flow rate of the drilling fluid is adjusted using the first circulation flow rate adjustment coefficient α1; If the difference between the change in particle size of the cuttings and the preset particle size change is greater than the preset first particle size change difference and less than or equal to the preset second particle size change difference, the second circulation flow rate adjustment coefficient α2 is used to adjust the circulation flow rate of the drilling fluid; If the difference between the change in particle size of the cuttings and the preset change in particle size is greater than the preset second particle size change difference, the circulation flow rate of the drilling fluid is adjusted using the third circulation flow rate adjustment coefficient α3; Among them, the adjustment formula for the circulation flow of drilling fluid is: , μ is the circulation flow rate of drilling fluid after adjustment, μ0 is the circulation flow rate of drilling fluid before adjustment, αn is the nth circulation flow rate adjustment coefficient, n=1, 2, 3; The cutting feature similarity is the similarity between the texture orientation of the rock cuttings before cutting and the texture orientation of the rock cuttings after cutting; The calculation formula for the cutting feature similarity of the drilled rock cuttings is: ， Wherein, ω is the cutting feature similarity, θ1 is the acute angle between the texture trend of the cuttings after cutting and the standard line, and θ2 is the acute angle between the texture trend of the cuttings before cutting and the standard line; The standard line of drilled cuttings is a standard line that meets a preset benchmark and is obtained through data modeling analysis of historical data within three months.

2. The fracturing drilling method for complex formations according to claim 1, characterized in that: The process of obtaining the acoustic wave receiving rates at several points of the fixture collected by the formation drilling test includes: Setting ultrasonic sensors at several points of the target complex formation; Starting the crushing drilling equipment to perform a formation drilling test on the target drilling position; Receive the sound wave signal from each ultrasonic sensor and obtain the sound wave receiving rate at each point.

3. The fracturing drilling method for complex formations according to claim 1, characterized in that: The change in particle size of the rock cuttings is the ratio of the difference between the particle size of the rock cuttings after a single cycle of the circulation flow of the drilling fluid and the initial particle size of the rock cuttings to the initial particle size of the rock cuttings.

4. The fracturing drilling method for complex formations according to claim 1, characterized in that: The circulation flow rate of the drilling fluid is the flow rate of the drilling fluid after it is initially pumped from the ground to the lower part of the drill bit through the drill pipe and then flows to the ground through the borehole.

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