Method and device for continuous monitoring of deformation of surrounding rock during drilling

Abstract

The present application relates to the technical field of surrounding rock deformation monitoring, and particularly relates to a surrounding rock deformation continuous monitoring method and device applied to a drilling process, target monitoring points are determined from each monitoring point based on abnormal conditions of detection deformation speeds of each monitoring point in the drilling process at the same time; the number of target monitoring points at each time and the correlation between the detection deformation speeds of the target monitoring points are used to determine deformation abnormal synchronism of all target monitoring points at each time, the abnormal conditions of the detection deformation speeds of each monitoring point at each time are combined to obtain the influence degree of drilling rig vibration on the surrounding rock deformation amount of each monitoring point at each time, the detection deformation speed is adjusted reversely to obtain an updated surrounding rock deformation speed after the influence of vibration is eliminated, and the accuracy and reliability of the surrounding rock deformation speed acquisition are improved, and the accuracy and reliability of the surrounding rock deformation continuous monitoring are improved when the surrounding rock deformation continuous monitoring is performed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of surrounding rock deformation monitoring, and particularly relates to a surrounding rock deformation continuous monitoring method and device applied to a drilling process. BACKGROUND

[0002] In underground engineering, such as coal mine shafts, tunnels, and the like, the surrounding rock (such as rock strata, soil layers) in a drilling area is prone to sudden hole diameter shrinkage, strain sudden increase, local collapse, and the like after being disturbed by excavation, and thus, monitoring of surrounding rock deformation during drilling is crucial. In the prior art, during continuous monitoring of surrounding rock deformation during drilling, the deformation speed of the surrounding rock at a monitoring point in the drilling is generally obtained, and the deformation speed change trend is used to quantify abnormal surrounding rock deformation, so as to achieve continuous monitoring of surrounding rock deformation. However, in an actual drilling scenario, the rotation vibration signal of a drilling machine will interfere with the actual deformation signal, that is, the accurate acquisition of the deformation speed of the surrounding rock will be interfered with, resulting in a large error between the detected deformation speed of the surrounding rock and the actual deformation speed, and thus, the accuracy of surrounding rock deformation monitoring is reduced. SUMMARY

[0003] In order to solve the technical problem of low accuracy of the prior art surrounding rock deformation continuous monitoring method during drilling, the purpose of the present application is to provide a surrounding rock deformation continuous monitoring method and device applied to a drilling process, and the technical solution adopted is as follows:

[0004] In a first aspect of the present application, a surrounding rock deformation continuous monitoring method applied to a drilling process is provided, comprising:

[0005] determining a target monitoring point from the monitoring points based on abnormal conditions of the detected deformation speed of each monitoring point in the drilling at the same time;

[0006] determining deformation abnormality synchronism for all target monitoring points at each time according to the number of target monitoring points at each time and the correlation between the detected deformation speeds of the target monitoring points;

[0007] obtaining the degree of influence of drilling machine vibration on the deformation amount of each monitoring point at each time from the deformation abnormality synchronism and the abnormal conditions of the detected deformation speed of each monitoring point at each time;

[0008] reversely adjusting the detected deformation speed according to the degree of influence to obtain an updated deformation speed, and the updated deformation speed is used to indicate continuous monitoring of surrounding rock deformation.

[0009] In an exemplary embodiment, after the updated deformation speed is obtained, the surrounding rock deformation continuous monitoring method applied to the drilling process further comprises:

[0010] The deformation instability feature of each monitoring point at each time is obtained from the abnormal situation and the speed change degree of the updated deformation speed of each monitoring point at each time;

[0011] The surrounding rock deformation risk index at each time is obtained from the distribution of the instability monitoring points in the borehole at each time and the deformation instability feature; the instability monitoring points are obtained from the deformation instability feature;

[0012] The surrounding rock deformation danger degree is obtained from the number growth of the instability monitoring points at each time and the index change degree of the surrounding rock deformation risk index at each time.

[0013] In an exemplary embodiment, the deformation instability feature acquisition process comprises:

[0014] The second speed difference of the monitoring point at each time in the reference period of the target time and the speed change degree of the updated deformation speed are determined; the second speed difference is the speed difference between the updated deformation speed at each time and the second preset reference deformation speed; the target time is any time;

[0015] The deformation instability feature of the monitoring point at the target time is obtained by fusing the second speed difference and the speed change degree of the updated deformation speed of the monitoring point at each time in the reference period of the target time; the deformation instability feature is positively correlated with the second speed difference and the speed change degree.

[0016] In an exemplary embodiment, the monitoring point with the deformation instability feature greater than or equal to the preset deformation instability threshold at the target time is determined as the instability monitoring point at the target time.

[0017] In an exemplary embodiment, the surrounding rock deformation risk index acquisition process comprises:

[0018] The instability region at the target time is obtained, and the instability region is composed of adjacent instability monitoring points;

[0019] The surrounding rock deformation risk index at the target time is obtained by fusing the maximum value of the deformation instability feature of each instability region, the number of instability monitoring points contained, and the depth in the borehole; the surrounding rock deformation risk index is positively correlated with the maximum value of the deformation instability feature, the number of instability monitoring points, and the depth.

[0020] In an exemplary embodiment, the surrounding rock deformation danger degree acquisition process at the current time comprises:

[0021] The surrounding rock deformation danger degree at the current time is obtained by fusing the index change degree of the surrounding rock deformation risk index at each time in the reference period of the current time and the number growth of the instability monitoring points; the surrounding rock deformation danger degree is positively correlated with the index change degree and the number growth.

[0022] In an exemplary embodiment, the process of acquiring the target monitoring point includes:

[0023] The first velocity difference between the detected deformation velocity of each monitoring point at the target time and the first preset benchmark deformation velocity is determined, and the monitoring points whose first velocity difference at the target time is greater than or equal to the preset velocity difference threshold are determined as the target monitoring points at the target time; the target time is any time.

[0024] In an exemplary embodiment, the process of obtaining the deformation anomaly synchronization includes:

[0025] Obtain the deviation of the first velocity difference between any two target monitoring points at the target time;

[0026] By integrating the deviations of all two target monitoring points at the target time and combining them with the number of target monitoring points at the target time, the deformation anomaly synchronicity at the target time is obtained; the deformation anomaly synchronicity is inversely correlated with the deviation and positively correlated with the number of target monitoring points.

[0027] In one exemplary embodiment, the process of obtaining the degree of influence includes:

[0028] Based on the abnormal synchronization of deformation at each moment and the first velocity difference at each monitoring point at each moment, the degree of influence at each monitoring point at each moment is obtained; the degree of influence is positively correlated with both the abnormal synchronization of deformation and the first velocity difference.

[0029] In a second aspect of the present invention, a device for continuous monitoring of surrounding rock deformation during drilling is provided, comprising: a memory and a processor; the memory is connected to the processor; the memory is used to store program instructions; the processor is used to implement the above-described method for continuous monitoring of surrounding rock deformation during drilling when the program instructions are executed.

[0030] The present invention has the following beneficial effects: Since the impact of vibration caused by the contact between the drill rod and the surrounding rock during drilling on the deformation rate of the surrounding rock is inconsistent with the normal deformation of the surrounding rock, the deformation rate detected at each monitoring point at each moment in the borehole is analyzed to obtain the degree of influence of drilling vibration on the deformation of the surrounding rock at each monitoring point at each moment. The higher the degree of influence, the more serious the impact of vibration on the deformation of the surrounding rock. Based on this, the deformation rate detected at each monitoring point at each moment is adjusted to obtain the deformation rate of the surrounding rock after eliminating the influence of vibration, thereby improving the accuracy and reliability of obtaining the deformation rate of the surrounding rock. This improves the accuracy and reliability of continuous monitoring of the surrounding rock deformation. Attached Figure Description

[0031] Figure 1 This is a flowchart of a method for continuous monitoring of surrounding rock deformation during drilling, provided by an embodiment of the present invention.

[0032] Figure 2 This is a flowchart of obtaining the abnormal synchronization of deformation provided in one embodiment of the present invention;

[0033] Figure 3 This is a flowchart of the steps included in a method for continuous monitoring of surrounding rock deformation during drilling, provided by an embodiment of the present invention.

[0034] Figure 4 This is a flowchart illustrating the process of obtaining deformation instability features according to an embodiment of the present invention;

[0035] Figure 5 This is a flowchart illustrating the acquisition of surrounding rock deformation risk indicators according to an embodiment of the present invention. Detailed Implementation

[0036] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the specific implementation methods, structures, features, and effects of the present invention are described in detail below with reference to the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. All data and information collected in this application have been obtained with full consent.

[0038] In borehole drilling, surrounding rock instability is the most typical safety hazard. If the surrounding rock undergoes severe deformation due to stress release and structural damage but is not detected in time, it may directly lead to borehole collapse (the collapse of surrounding rock blocking the borehole), water and mud inrush (groundwater is conducted through fissures in the surrounding rock, and high-pressure water suddenly rushes into the construction area), or even trigger a larger-scale surrounding rock collapse, threatening the lives of construction personnel and the integrity of drilling rigs and support equipment. This embodiment provides a method for continuous monitoring of surrounding rock deformation during the drilling process, which enables continuous monitoring of surrounding rock deformation. Borehole drilling is a dynamic process, and the drill will continuously drill deeper. The deformation of the surrounding rock will also change dynamically with increasing depth and time. In order to detect deformation trends in a timely manner, it is necessary to ensure the continuity of monitoring data and avoid the problem of data lag caused by the progress of construction.

[0039] In this embodiment, a monitoring point is deployed at preset intervals along the borehole depth, such as one monitoring point every 1 meter, thus creating multiple monitoring points within the borehole. The different monitoring points are located at different depths within the borehole. This embodiment uses fiber Bragg grating sensors to detect the deformation of the surrounding rock at each monitoring point. The fiber Bragg grating sensors are mounted on the borehole wall and lowered into the borehole synchronously with the drill rod to avoid data gaps caused by lowering the sensors after drilling is complete. This allows for the acquisition of time-series data on the deformation at each monitoring point, where the deformation at each moment is the accumulated deformation from the initial moment.

[0040] The sensing principle of a fiber Bragg grating sensor is as follows: When a broadband beam of light (containing multiple wavelengths) is transmitted through an optical fiber and passes through a fiber Bragg grating, light of a specific wavelength (i.e., the Bragg wavelength) that satisfies the Bragg condition is reflected back by the fiber Bragg grating, while other wavelengths are transmitted almost without loss. Deformation of the surrounding rock in a borehole typically causes bending or displacement of the borehole. This bending causes the fiber Bragg grating sensor embedded within it to be stretched or compressed, resulting in a change in the Bragg wavelength. This change in Bragg wavelength can be obtained using a demodulator and converted into the deformation of the surrounding rock.

[0041] In one exemplary embodiment, the sampling frequency of the surrounding rock deformation of the fiber Bragg grating sensor is set according to actual needs. In this embodiment, sampling is taken once every 10 seconds.

[0042] like Figure 1 As shown in the figure, the method for continuous monitoring of surrounding rock deformation during drilling provided in this embodiment includes the following steps:

[0043] Step S1: Based on the abnormal situation of the deformation rate detected at each monitoring point in the borehole at the same time, determine the target monitoring point from each monitoring point;

[0044] Step S2: Based on the number of target monitoring points at each time point and the correlation between the detected deformation rates of the target monitoring points, determine the synchronicity of deformation anomalies for all target monitoring points at each time point;

[0045] Step S3: Based on the abnormal synchronicity of deformation and the abnormality of the detected deformation rate at each monitoring point at each time, the degree of influence of drilling rig vibration on the surrounding rock deformation at each monitoring point at each time is obtained.

[0046] Step S4: Adjust the detection deformation speed in reverse based on the degree of influence to obtain the updated deformation speed.

[0047] The following detailed explanation of each step, in conjunction with the accompanying drawings, is provided.

[0048] Step S1: Based on the abnormal situation of the deformation rate detected at each monitoring point in the borehole at the same time, determine the target monitoring point from each monitoring point.

[0049] During drilling, contact and collision between the drill rod and the surrounding rock cause vibration. The operation of the drilling rig, the impact or collision of the drill bit, etc., can all cause momentary, minute displacements of the surrounding rock in localized areas. These displacements are not caused by the deformation of the surrounding rock itself, but by the vibration of the equipment. The effect of vibration on deformation is instantaneous; for example, when the drill bit collides with the rock wall, it can cause a sudden increase in the deformation of the surrounding rock at a certain moment, which may quickly recover or fluctuate significantly in the next moment. Therefore, by analyzing the deformation rate at each monitoring point at various moments within a short period, it is possible to determine whether the drilling rig vibration has had an impact.

[0050] Taking the current moment as an example, a reference time period is determined. The end time of the reference time period is the current moment, and the duration of the reference time period (i.e., the number of moments it includes) is set according to actual needs. This embodiment uses a reference time period including 60 moments as an example. It should be understood that each moment has its corresponding reference time period. By setting any moment in the reference time period of the current moment as the target moment, the reference time period of the target moment can be obtained using the method for obtaining the reference time period of the current moment. Furthermore, for ease of explanation, any monitoring point is set as a candidate monitoring point.

[0051] Based on the above process, the surrounding rock deformation at each time point within the reference time period of the candidate monitoring point at the current time is obtained, resulting in time-series data of surrounding rock deformation. It should be understood that the surrounding rock deformation gradually increases over time, although it may remain constant at certain times under special circumstances. However, the overall trend of surrounding rock deformation is increasing. Therefore, for the time-series data of surrounding rock deformation, the difference between the deformation at the later time point and the deformation at the earlier time point is calculated. This difference is used as the deformation rate of the surrounding rock at the later time point, thus obtaining the deformation rate at each time point. Since the obtained deformation rate is based on detection by a fiber optic grating sensor, it is defined as the detected deformation rate. This yields the sequence of detected deformation rates of the surrounding rock at the candidate monitoring point within the reference time period at the current time, including the detected deformation rates at each time point. Furthermore, the sequence of detected deformation rates of the surrounding rock at each monitoring point within the reference time period at the current time is obtained.

[0052] Due to the influence of vibration during surrounding rock deformation detection, the deformation amount and detection rate measured by the drilling rig at the target time cannot fully represent the actual state of the surrounding rock. Disturbances during the drilling process are present, making the detection rate data at the target time unreliable and unable to accurately reflect the true deformation of the surrounding rock. Drilling rig vibration often causes significant changes in deformation within a short period. These changes often manifest as a sudden increase or fluctuation in the detection rate, and these fluctuations are brief and discontinuous, differing considerably from the actual deformation state of the surrounding rock. Therefore, it is necessary to eliminate these instantaneous errors caused by vibration to ensure the accuracy of the surrounding rock deformation monitoring data.

[0053] Based on the anomalies in the detected deformation rates at each monitoring point at the target time, a target monitoring point for the target time is determined from among the monitoring points. In an exemplary embodiment, a first velocity difference is determined between the detected deformation rate of a candidate monitoring point at the target time and a first preset benchmark deformation rate. The first preset benchmark deformation rate is used as a comparison with normal deformation rates. The greater the difference between the detected deformation rate of a candidate monitoring point at the target time and the first preset benchmark deformation rate, the more abnormal the detected deformation rate, and the greater the first velocity difference between the candidate monitoring point and the target time. The first preset benchmark deformation rate can be obtained manually based on experience, or it can be obtained by acquiring the detected deformation rates of the candidate monitoring point at each time within a reference period at the target time, obtaining the mode, which reflects the central tendency of the detected deformation rate changes at most times within the reference period at the target time, and using this mode as the first preset benchmark deformation rate of the candidate monitoring point at the target time. When the detected deformation rate of the candidate monitoring point at the target time is greater than or equal to the first preset benchmark deformation rate, the difference between the detected deformation rate of the candidate monitoring point at the target time and the first preset benchmark deformation rate is calculated, and this difference is taken as the first velocity difference of the candidate monitoring point at the target time. When the detected deformation rate of the candidate monitoring point at the target time is less than the first preset benchmark deformation rate, it indicates that the detected deformation rate of the candidate monitoring point at the target time is small, the deformation amount at the target time is small, and the deformation amplitude is relatively safe. In this case, the first velocity difference of the candidate monitoring point at the target time is set to 0.

[0054] Using the above process, the first velocity difference of each monitoring point at the target time is obtained. The larger the first velocity difference, the more the detected deformation rate of the monitoring point at the target time deviates from the normal deformation rate. In an exemplary embodiment, the ratio of the first velocity difference to the first preset benchmark deformation rate is calculated as the abnormal change rate corresponding to the first velocity difference. This embodiment presets a velocity difference threshold, which is used to determine whether the abnormal change rate corresponding to the obtained first velocity difference is large. The specific value of the preset velocity difference threshold is set according to the actual judgment needs. If a safer judgment logic is required, the preset velocity difference threshold can be set smaller, such as 0.5. The abnormal change rate corresponding to the first velocity difference of each monitoring point at the target time is compared with the magnitude of the preset velocity difference threshold. The abnormal change rate corresponding to the first velocity difference that is greater than or equal to the preset velocity difference threshold is determined, and the monitoring points whose abnormal change rate corresponding to the first velocity difference at the target time is greater than or equal to the preset velocity difference threshold are determined as the target monitoring points at the target time. Thus, the target monitoring points at each time within the reference time period at the current time are obtained.

[0055] Step S2: Based on the number of target monitoring points at each time point and the correlation between the detection deformation rate of the target monitoring points, determine the synchronicity of deformation anomalies for all target monitoring points at each time point.

[0056] When the drilling rig starts and the drill bit impacts hard rock strata, the drilling rig vibration is a systemic disturbance transmitted along the drill rod, causing synchronous anomalies in deformation at all monitoring points. However, the actual deformation of the surrounding rock is affected by the difference in stress distribution along the borehole depth, resulting in variations in deformation at different monitoring points. For example, the stress in the surrounding rock is high in the middle of the borehole, leading to a faster rate of deformation; while the stress at the borehole opening is low, resulting in a slower rate of deformation. Therefore, comparing deformation data from multiple monitoring points can further verify the impact of vibration on each monitoring point. Thus, based on the number of target monitoring points at each time point and the correlation between the detected deformation rates of the target monitoring points, the synchronousity of deformation anomalies for all target monitoring points at each time point is determined. In an exemplary embodiment, such as... Figure 2 As shown, the following is a specific process for obtaining the synchronization of deformation anomalies:

[0057] Step S21: Obtain the deviation of the first velocity difference between any two target monitoring points at the target time.

[0058] For several target monitoring points at the target time, the deviation of the first velocity difference between any two target monitoring points at the target time is calculated. Based on the above analysis, this deviation is specifically the absolute value of the difference in the abnormal change rate of the first velocity difference. The deviation of the first velocity difference characterizes whether the abnormality of the detected deformation velocity of the two target monitoring points is consistent. The smaller the deviation of the first velocity difference, the more consistent the abnormality of the detected deformation velocity of the two target monitoring points is, and the more synchronous the deformation anomalies of the two target monitoring points are at the target time, that is, the higher the synchronicity of deformation anomalies. Thus, the deviation between any two possible target monitoring points at the target time is obtained.

[0059] Step S22: Combine the deviations of any two target monitoring points at the target time, and combine them with the number of target monitoring points at the target time to obtain the deformation anomaly synchronization at the target time.

[0060] Calculate the average deviation of the first velocity difference between any two possible target monitoring points at the target time. The smaller the average deviation, the higher the synchronization of deformation anomalies; the two are inversely correlated.

[0061] The more target monitoring points there are at the target time, the more monitoring points simultaneously show anomalies where the deformation rate deviates significantly from the normal situation at the target time. The higher the synchronicity of deformation anomalies at the target time, the more positively correlated the two are.

[0062] Therefore, by combining the average deviation of any two target monitoring points at the target time, and the number of target monitoring points at the target time, the deformation anomaly synchronization at the target time is obtained. Based on the above logic, a specific calculation method is given below:

[0063] ;

[0064] in, This indicates the abnormal synchronization of deformation at time i. This represents the number of target monitoring points at time i. This indicates the total number of monitoring points. This represents the percentage of target monitoring points at time i, which is essentially a measure of... Normalization, Let represent the average deviation of the first velocity difference between any two possible target monitoring points at time i, and exp represent an exponential function with the natural constant as the base.

[0065] Step S3: Based on the abnormal synchronization of deformation and the abnormality of the detected deformation rate at each monitoring point at each time, the degree of influence of drilling rig vibration on the surrounding rock deformation at each monitoring point at each time is obtained.

[0066] Step S2 obtains the synchronicity of deformation anomalies at each time point. The more monitoring points that simultaneously exhibit anomalies, and the more consistent the anomalies across different target monitoring points, the more the drilling rig transmits disturbances to multiple areas within the borehole during drilling, causing monitoring points at different depths and locations to be synchronously affected by vibration. In this case, the likelihood of each monitoring point being disturbed by drilling rig vibration at that time is greater. Therefore, based on the synchronicity of deformation anomalies at each time point, and the anomalies in the detected deformation rates at each monitoring point at each time point, the degree to which the surrounding rock deformation at each monitoring point is affected by drilling rig vibration at each time point is determined. The anomalies in the detected deformation rates at each monitoring point at each time point represent the first velocity difference between the monitoring points at each time point.

[0067] Accordingly, based on the synchronicity of deformation anomalies at each time point and the difference in the first velocity at each time point at each monitoring point, the degree of influence of drilling rig vibration on the surrounding rock deformation at each monitoring point at each time point is obtained. The greater the synchronicity of deformation anomalies, the higher the degree of influence of drilling rig vibration on the surrounding rock deformation at each monitoring point at the corresponding time point; the two are positively correlated. Similarly, the greater the difference in the first velocity at each time point at each monitoring point, the higher the degree of influence of drilling rig vibration on the surrounding rock deformation at each monitoring point at each time point; the two are also positively correlated. Based on the above logic, a specific calculation method for the degree of influence is given below:

[0068] ;

[0069] in, This indicates the degree to which the deformation of the surrounding rock at the c-th monitoring point at time i is affected by the drilling rig vibration. This represents the abnormal rate of change of the first velocity difference at time i for the c-th monitoring point, where norm represents the normalization function, such as the tanh function.

[0070] Step S4: Adjust the detection deformation speed in reverse based on the degree of influence to obtain the updated deformation speed.

[0071] The greater the difference in the first velocity of the detected deformation rate at the candidate monitoring points at the target time, the greater the difference from the normal deformation rate. Furthermore, the greater the abnormal synchronicity of the deformation at the target time, the higher the degree of influence of drilling rig vibration on the candidate monitoring points at the target time. This indicates the presence of a strong vibration source during drilling, causing the vibration to propagate to the surrounding rock and resulting in significant changes in the deformation data of many monitoring points. The less reliable the detected deformation rate of the candidate monitoring points at the target time, the less likely the surrounding rock deformation at the candidate monitoring points is to be a true deformation. Therefore, the greater the influence, the greater the reduction in the detected deformation rate. The detected deformation rate is then adjusted inversely based on the degree of influence, and the adjusted deformation rate becomes the updated deformation rate. In an exemplary embodiment, the following adjustment method is given:

[0072] ;

[0073] in, This represents the update deformation rate of the c-th monitoring point at time i. This represents the detected deformation rate at the c-th monitoring point at time i.

[0074] By obtaining the updated deformation rate of each monitoring point within the reference time period at the current moment, continuous monitoring of surrounding rock deformation can be carried out based on the updated deformation rate. The above steps yield deformation data that accurately reflects the true deformation of the surrounding rock. Since the stability of the surrounding rock is crucial during drilling operations, further analysis of the surrounding rock stability is necessary to prevent dangerous accidents such as surrounding rock collapse during drilling.

[0075] Rock instability does not occur suddenly, but rather through a gradual process of accelerated deformation followed by instability. For example, in soft rock formations, the deformation rate of the surrounding rock can gradually increase from 0.2 mm / h to over 1.0 mm / h, eventually leading to collapse. Therefore, by referring to the trend characteristics of deformation rate over a specific period, this signal can be detected in advance.

[0076] In one exemplary embodiment, such as Figure 3 As shown, after obtaining the updated deformation rate, the continuous monitoring method for surrounding rock deformation in the drilling process provided in this embodiment further includes the following steps:

[0077] Step S5: Obtain the deformation instability characteristics of each monitoring point at each time by observing the abnormalities and degree of velocity change in the updated deformation rate at each monitoring point at each time.

[0078] In one exemplary embodiment, such as Figure 4 As shown, the following is a specific process for obtaining deformation instability characteristics:

[0079] Step S51: Determine the difference in the second velocity at each time point within the reference time period of the target time, and the degree of velocity change of the updated deformation velocity.

[0080] The second velocity difference of the candidate monitoring point at each time point within the reference period of the target time is obtained in the same way as the first velocity difference described above. The second velocity difference is the velocity difference between the updated deformation rate and the second preset benchmark deformation rate at each time point. The second preset benchmark deformation rate can be obtained manually based on experience, or it can be obtained as follows: obtain the mode of the updated deformation rates of the candidate monitoring point at each time point within the reference period of the target time, and use this mode as the second preset benchmark deformation rate of the candidate monitoring point at the target time. When the updated deformation rate at a certain time point is greater than or equal to the second preset benchmark deformation rate, calculate the difference between the updated deformation rate at that time point and the second preset benchmark deformation rate, and use this difference as the second velocity difference at that time point; when the updated deformation rate at that time point is less than the second preset benchmark deformation rate, set the second velocity difference at that time point to 0. It should be understood that the larger the second velocity difference, the greater the difference between the updated deformation rate and the normal deformation rate, the faster the degree and rate of development towards instability, and the greater the corresponding deformation instability characteristics. Therefore, deformation instability characteristics are positively correlated with the second velocity difference.

[0081] Curve fitting is performed on the update deformation rate of candidate monitoring points at each time point within the reference period at the target time to obtain the fitted curve. Then, the slope of the tangent line for the update deformation rate at each time point in the fitted line is obtained, and the slope of the tangent line is used as the degree of change of the update deformation rate. It should be understood that the slope of the tangent line can be positive, 0, or negative. A positive value indicates that the update deformation rate at the corresponding time point is in a state of increasing rate, a negative value indicates that the update deformation rate at the corresponding time point is in a state of decreasing rate, and 0 indicates that the update deformation rate at the corresponding time point is in a state of stable rate. Regardless of whether the slope of the tangent line is positive, 0, or negative, the following condition is met: the larger the slope of the tangent line, the greater the change in the update deformation rate at the corresponding time point, that is, the greater the degree of rate change. The larger the slope of the tangent line, the more obvious the increase in the update deformation rate, the faster the degree and rate of the surrounding rock development towards the unstable state, and the greater the corresponding deformation instability characteristics. Therefore, the deformation instability characteristics are positively correlated with the degree of change of the update deformation rate.

[0082] Step S52: By integrating the second velocity difference and the velocity change of the updated deformation velocity at each time point within the reference time period of the monitoring point at the target time, the deformation instability characteristics of the monitoring point at the target time are obtained.

[0083] First, the maximum and minimum values ​​of the rate of change of the update deformation speed (i.e., the tangent slope) of the candidate monitoring point at each time point within the reference period of the target time are obtained. The tangent slope of the candidate monitoring point at each time point within the reference period of the target time is normalized using a maximum / minimum value normalization method. Then, the sum of the normalized tangent slopes of the candidate monitoring point at all times within the reference period of the target time is calculated. Finally, the ratio of the normalized tangent slope of the candidate monitoring point at each time point within the reference period of the target time to this sum is calculated. The result is the importance weight of the candidate monitoring point at each time point within the reference period of the target time. Using the above method, the sum of the importance weights of the candidate monitoring point at all times within the reference period of the target time is made equal to 1.

[0084] The differences in the second velocity of candidate monitoring points at each time step within the reference period at the target time are normalized (e.g., using the tanh function). Then, based on the importance weights of each time step within the reference period at the target time, the normalized differences in the second velocity of candidate monitoring points at each time step within the reference period at the target time are weighted and summed. The result is the deformation instability characteristic of the candidate monitoring points at the target time. The greater the difference between the updated deformation velocity and the normal deformation velocity, the stronger the trend of the updated deformation velocity increasing, the faster the rate of development towards instability, and the more attention is required. Using the above process, the deformation instability characteristics of each monitoring point at each time step are obtained.

[0085] Step S6: Obtain the surrounding rock deformation risk index at each time point based on the distribution of instability monitoring points in the borehole and the deformation instability characteristics.

[0086] Step S5 obtains the deformation and instability characteristics of each monitoring point at each moment. Since the surrounding rock risk during drilling has a spatial correlation along the borehole axis, meaning that surrounding rock instability is rarely an isolated problem at a single monitoring point, but rather a continuous anomaly within a certain segment of the axis—for example, in weak rock strata or stress concentration sections traversed by the borehole—multiple adjacent monitoring points may simultaneously become unstable. Therefore, this step also requires analyzing the spatial continuity of the deformation and instability characteristics of each monitoring point.

[0087] First, instability monitoring points are obtained based on deformation instability characteristics. In an exemplary embodiment, a preset deformation instability threshold is used to determine whether the deformation instability characteristics of each monitoring point are large. The preset deformation instability threshold ranges from 0 to 1, and the specific value is set according to actual needs. For example, if a safer judgment logic is required, the preset deformation instability threshold can be set smaller, such as 0.6. For a target time, the deformation instability characteristics of each monitoring point at the target time are compared with the preset deformation instability threshold, and monitoring points that are greater than or equal to the preset deformation instability threshold are obtained. The monitoring points that are greater than or equal to the preset deformation instability threshold at the target time are used as the instability monitoring points at the target time.

[0088] In one exemplary embodiment, such as Figure 5 As shown, the following is a specific process for obtaining the surrounding rock deformation risk index:

[0089] Step S61: Obtain the unstable region at the target time.

[0090] For the target time, along the borehole axis from top to bottom, i.e., starting from the borehole opening and moving towards the depth, consecutive adjacent instability monitoring points are grouped into an instability region, thus obtaining several instability regions at the target time. It should be understood that for isolated instability monitoring points, i.e., those without any adjacent instability monitoring points, they are considered noise and not treated as separate instability regions.

[0091] Step S62: Combine the maximum value of deformation and instability characteristics of each unstable region, the number of instability monitoring points included, and the depth in the borehole to obtain the surrounding rock deformation risk index at the target time.

[0092] For any unstable region, since it includes several unstable monitoring points, the maximum value of the deformation and unstable characteristics of each monitoring point is obtained as the maximum value of the deformation and unstable characteristics of that unstable region. The larger the maximum value of the deformation and unstable characteristics, the greater the risk of surrounding rock deformation in that unstable region, and the greater the surrounding rock deformation risk index at the target time. Therefore, the surrounding rock deformation risk index is positively correlated with the maximum value of the deformation and unstable characteristics.

[0093] Obtain the number of instability monitoring points contained in the unstable area. The more instability monitoring points contained, the wider the coverage of the surrounding rock deformation risk corresponding to the unstable area. The greater the surrounding rock deformation risk in the unstable area, the greater the surrounding rock deformation risk index. Therefore, the surrounding rock deformation risk index is positively correlated with the number of instability monitoring points contained.

[0094] The depth of the unstable region within the borehole is determined. The deeper the region, the greater the pressure from the overlying strata. Furthermore, deeper areas have limited construction space, making support and reinforcement operations more complex and posing a greater risk. In other words, the greater the risk of surrounding rock deformation in the unstable region, the higher the surrounding rock deformation risk index. Therefore, the surrounding rock deformation risk index is positively correlated with the depth of the unstable region within the borehole. In an exemplary embodiment, the center point of the unstable region along the borehole axis (i.e., the borehole depth direction) is obtained, and the distance between this center point and the borehole opening along the borehole axis is calculated. This distance is taken as the depth of the unstable region within the borehole.

[0095] Based on the logic above, the following is one method for calculating the surrounding rock deformation risk index:

[0096] ;

[0097] ;

[0098] in, This represents the surrounding rock deformation risk index at time i. Let represent the maximum deformation and instability characteristic of the q-th instability region at time i, and let Q represent the number of instability regions at time i. This represents the number of instability monitoring points contained in the q-th instability region at time i. This represents the depth of the q-th instability region in the borehole at time i. This represents the risk weight of the deformation and instability characteristics of the q-th instability region at time i. The specific implementation method is as follows: calculate the product of the number of instability monitoring points corresponding to each instability region at time i and the depth in the borehole, then calculate the sum of the products corresponding to all instability regions at time i, and finally calculate... The ratio of the product to the sum of the products yields the following result. This ensures that the sum of the risk weights of each unstable region at time i is 1.

[0099] It should be understood that the deformation of the surrounding rock during drilling will show a pattern of gradual accumulation → local instability → spread. The more instability monitoring points there are, the more the deterioration trend gradually expands in space, the more rapidly the instability range expands, and the deeper the instability area, the greater the pressure of the overlying rock strata. Moreover, the construction space in deep areas is limited, the support and reinforcement operations are more complex, and the degree of harm is also greater. In order to avoid further construction accidents, it is necessary to assign a larger risk weight.

[0100] Step S7: Based on the increase in the number of instability monitoring points at each time point and the degree of change in the surrounding rock deformation risk index at each time point, the degree of surrounding rock deformation danger is obtained.

[0101] Based on the surrounding rock deformation risk index obtained in step S6, the surrounding rock deformation risk index at each time point within the reference time period at the current time is obtained, and then arranged in chronological order to obtain the sequence of surrounding rock deformation risk indexes corresponding to the current time. Simultaneously, the number of instability monitoring points at each time point within the reference time period at the current time is obtained.

[0102] The process involves obtaining the growth rate of the number of instability monitoring points at each time point within the reference time period at the current moment. Specifically, for any two adjacent times within the reference time period, the growth rate of the number of instability monitoring points at the later time point relative to the earlier time point is obtained. This is calculated as the difference between the number of instability monitoring points at the later time point and the number at the earlier time point; this difference is the growth rate. It should be understood that if the number of instability monitoring points at the later time point is less than or equal to the number at the earlier time point, the growth rate is set to 0. This yields the growth rate of the number of instability monitoring points at each time point within the reference time period at the current moment. For ease of subsequent processing, the growth rate of the number of instability monitoring points at each time point within the reference time period at the current moment is normalized. Specifically, the sum of the growth rates of the number of instability monitoring points at all times within the reference time period at the current moment is calculated to obtain the total growth rate. Then, the ratio of the growth rate of the number of instability monitoring points at each time point within the reference time period at the current moment to this total growth rate is calculated and used as the weighting coefficient for the number of instability monitoring points at each time point within the reference time period at the current moment. The greater the increase in the number of instability monitoring points at each moment, the wider the range of instability monitoring points is during the drilling process. This means that a greater weight needs to be given when calculating the degree of surrounding rock deformation risk at the current moment, and the degree of surrounding rock deformation risk at the current moment is greater. The two are positively correlated.

[0103] To obtain the degree of change of the surrounding rock deformation risk index at each time point within a reference time period at the current time, in an exemplary embodiment, curve fitting is performed on the sequence of surrounding rock deformation risk indices corresponding to the current time point to obtain a fitted curve. Then, the tangent slope of the surrounding rock deformation risk index at each time point in the fitted line is obtained, and the tangent slope is used as the degree of change of the surrounding rock deformation risk index. It should be understood that the tangent slope may be positive, 0, or negative. A positive value indicates that the surrounding rock deformation risk index at the corresponding time point is increasing, a negative value indicates that the surrounding rock deformation risk index at the corresponding time point is decreasing, and 0 indicates that the surrounding rock deformation risk index at the corresponding time point is stable. Regardless of whether the tangent slope is positive, 0, or negative, the following condition is met: the larger the tangent slope, the greater the increase in the surrounding rock deformation risk index at the corresponding time point, that is, the greater the degree of change of the index, the faster the deterioration of the surrounding rock deformation, and the greater the degree of danger of the surrounding rock deformation at the current time point. Therefore, the two are positively correlated. In this embodiment, the degree of change of the surrounding rock deformation risk index at each time within the reference time period at the current time is normalized using the sigmoid function, so as to limit the tangent slope to a numerical range of 0-1, which facilitates subsequent data processing.

[0104] Based on the number weighting coefficients of instability monitoring points at each time point within the reference time period at the current time, the degree of change of the surrounding rock deformation risk index at each time point within the reference time period at the current time, after normalization using the sigmoid function, is weighted and summed to obtain the degree of surrounding rock deformation risk at the current time.

[0105] Therefore, the faster the deterioration rate of the surrounding rock deformation at each time point within the reference period at the current time, and the greater the increase in the number of instability monitoring points at each time point, it indicates that during the drilling process, the range of instability monitoring points at the current time point is becoming wider and wider, the chain reaction of the instability area is becoming more and more serious, and ultimately the degree of danger of the surrounding rock deformation at the current time point is greater and the risk level is higher.

[0106] This allows us to obtain the current level of surrounding rock deformation risk, enabling real-time monitoring of the surrounding rock deformation risk during drilling, i.e., continuous monitoring of surrounding rock deformation during drilling.

[0107] In subsequent practical applications, a preset danger level threshold can be established. This threshold is used to determine whether the obtained surrounding rock deformation danger level is high. The value range of this preset danger level threshold is 0-1, and the specific value is set according to the actual judgment needs. If a safer early warning logic is required, the preset danger level threshold can be set smaller, such as 0.7. If the current surrounding rock deformation danger level is greater than or equal to the preset danger level threshold, it indicates that multiple depth monitoring points are synchronously unstable, requiring the activation of the highest level emergency response. In this case, the current surrounding rock deformation is determined to be highly dangerous, and a high-risk alarm signal is output to facilitate the immediate implementation of relevant safety measures, such as immediate work stoppage.

[0108] As another implementation method, two unequal danger thresholds can be set, such as 0.7 and 0.4, thus forming three danger zones: greater than or equal to 0.7, less than 0.7 but greater than or equal to 0.4, and less than 0.4. The danger zone of the surrounding rock deformation at the current moment is determined, and a corresponding danger alarm signal is output based on the danger zone, which can be a high-risk alarm signal, a medium-risk alarm signal, or a low-risk alarm signal, facilitating immediate implementation of relevant safety measures.

[0109] This embodiment also provides a continuous monitoring device for surrounding rock deformation during drilling, comprising: a memory and a processor; the memory is connected to the processor, the memory is used to store program instructions; the processor is used to implement the steps in the above embodiment of the continuous monitoring method for surrounding rock deformation during drilling when the program instructions are executed.

[0110] In one exemplary embodiment, the present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps described in the embodiment of the method for continuous monitoring of surrounding rock deformation applied during drilling.

[0111] It should be noted that the order of the above embodiments of the present invention is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0112] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

Claims

1. A method for continuous monitoring of surrounding rock deformation during drilling, characterized in that, include: Based on the abnormal deformation rate detected at each monitoring point in the borehole at the same time, the target monitoring point is determined from each monitoring point; Based on the number of target monitoring points at each time point and the correlation between the detected deformation rates of the target monitoring points, the synchronicity of deformation anomalies for all target monitoring points at each time point is determined. Based on the abnormal synchronicity of the deformation and the abnormality of the detected deformation rate at each monitoring point at each time, the degree of influence of drilling rig vibration on the surrounding rock deformation at each monitoring point at each time can be obtained. The detected deformation rate is adjusted in reverse based on the degree of influence to obtain an updated deformation rate, which is used to indicate continuous monitoring of surrounding rock deformation. The method for obtaining the abnormal synchronization of deformation is as follows: The first velocity difference between the detected deformation velocity of each monitoring point at the target time and the first preset benchmark deformation velocity is determined, and the monitoring points whose first velocity difference at the target time is greater than or equal to the preset velocity difference threshold are determined as the target monitoring points at the target time; the target time is any time. The formula for calculating the abnormal synchronization of deformation is as follows: ;in, This indicates the abnormal synchronization of deformation at time i. This represents the number of target monitoring points at time i. This represents the total number of monitoring points; exp represents an exponential function with the natural constant as its base. This represents the average deviation of the first velocity difference between any two possible target monitoring points at time i. The formula for calculating the degree of impact is as follows: ;in, This indicates the degree to which the deformation of the surrounding rock at the c-th monitoring point at time i is affected by the drilling rig vibration. denoted as the abnormal rate of change of the first velocity difference at time i for the c-th monitoring point, and norm denotes the normalization function.

2. The method for continuous monitoring of surrounding rock deformation during drilling as described in claim 1, characterized in that, After obtaining the updated deformation rate, the method for continuous monitoring of surrounding rock deformation applied during the drilling process further includes: The deformation instability characteristics of each monitoring point at each time point are obtained by analyzing the abnormalities and the degree of velocity change in the updated deformation rate at each monitoring point at each time point. The surrounding rock deformation risk index at each moment is obtained from the distribution of instability monitoring points in the borehole and the deformation instability characteristics; the instability monitoring points are obtained from the deformation instability characteristics. The degree of surrounding rock deformation hazard is obtained by analyzing the increase in the number of instability monitoring points at each time point and the degree of change in the surrounding rock deformation risk indicators at each time point.

3. The method for continuous monitoring of surrounding rock deformation during drilling as described in claim 2, characterized in that, The process of obtaining the deformation instability characteristics includes: The second velocity difference of the monitoring point at each time point within the reference period of the target time, and the degree of velocity change of the updated deformation velocity are determined; the second velocity difference is the velocity difference between the updated deformation velocity at each time point and the second preset benchmark deformation velocity; the target time is any time point. By integrating the second velocity difference and the velocity change of the updated deformation velocity at each time point within the reference period of the target time, the deformation instability characteristics of the monitoring point at the target time are obtained; the deformation instability characteristics are positively correlated with the second velocity difference and the velocity change.

4. The method for continuous monitoring of surrounding rock deformation during drilling as described in claim 3, characterized in that, The monitoring points whose deformation and instability characteristics at the target time are greater than or equal to the preset deformation and instability threshold are determined as the instability monitoring points at the target time.

5. The method for continuous monitoring of surrounding rock deformation during drilling as described in claim 3, characterized in that, The process of obtaining the surrounding rock deformation risk index includes: Obtain the unstable region at the target time, wherein the unstable region is composed of adjacent unstable monitoring points; By integrating the maximum value of deformation and instability characteristics of each unstable region, the number of instability monitoring points included, and the depth in the borehole, the surrounding rock deformation risk index at the target time is obtained; the surrounding rock deformation risk index is positively correlated with the maximum value of deformation and instability characteristics, the number of instability monitoring points, and the depth.

6. The method for continuous monitoring of surrounding rock deformation during drilling as described in claim 2, characterized in that, The process of obtaining the current level of surrounding rock deformation risk includes: By integrating the degree of change of the surrounding rock deformation risk indicators at each time point within the reference period and the increase in the number of instability monitoring points, the degree of surrounding rock deformation risk at the current time is obtained; the degree of surrounding rock deformation risk is positively correlated with both the degree of change of the indicators and the increase in the number of monitoring points.

7. A continuous monitoring device for surrounding rock deformation during drilling, characterized in that it comprises: Memory and processor; The memory is connected to the processor; The memory is used to store program instructions; The processor is configured to implement, when program instructions are executed, the method for continuous monitoring of surrounding rock deformation applied during the drilling process as described in any one of claims 1-6.

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