A tracer-based fracturing fracture identification prediction system and method

Abstract

This invention discloses a tracer-based fracturing fracture identification and prediction system and method, specifically relating to the field of environmental safety prediction technology. It includes a tracer injection module, a tracer injection optimization module, a tracer fracture flow path acquisition module, a fracturing fracture propagation stability analysis module, a fracturing fracture propagation anomaly assessment module, and a fracturing fracture anomaly prediction and response module. This invention collects fracturing operation data during fracturing fluid injection, calculates a fracturing operation safety control index, and through calculation, combined with real-time data and an early warning mechanism, can scientifically adjust the tracer injection strategy to achieve a balance between safety and operational efficiency. By monitoring flow path data, it calculates a fracture propagation stability early warning index to predict the stability of fracture propagation behavior. Based on the entropy surge theory, it calculates a fracture propagation anomaly prediction coefficient to quantify the risk value of fracture propagation, achieving accurate fracture anomaly early warning and response in fracturing operations.

Description

Technical Field

[0001] This invention relates to the field of fracture safety prediction technology, and more specifically, to a tracer-based fracturing fracture identification and prediction system and method. Background Technology

[0002] Tracer technology is a key tool for identifying and monitoring fracturing fractures. Based on their physicochemical properties, tracers can be classified into radioactive tracers, chemical tracers, and nano-tracers, among others. Selecting stable tracers under specific geological conditions can further improve the accuracy of fracture monitoring. By injecting specific tracers during fracturing, these tracers, flowing with the fracturing fluid through rock fractures, can provide dynamic information about the fractures, helping engineers track their formation and propagation paths. In the oil and gas extraction field, by integrating advanced tracer technology and fracture identification technology, the formation and propagation of fractures can be accurately identified and predicted, thereby guiding fracturing operations and improving operational safety.

[0003] Shale gas is an unconventional natural gas resource, typically stored in low-permeability shale formations. To extract shale gas economically and efficiently, hydraulic fracturing technology is usually used to create artificial fractures, thereby improving the fluidity and recovery rate of natural gas.

[0004] However, in practical use, it still has some shortcomings. For example, in the existing fracturing fracture identification and prediction methods, the fusion processing of tracer data and fracture flow path data is insufficient, there is a lack of a unified data model, and it is difficult to fully reflect the stability of fracture propagation.

[0005] In existing fracturing crack identification and prediction methods, crack propagation parameters are mostly analyzed separately, lacking coupling effect modeling, making it impossible to accurately assess and warn of the risk of crack runaway, resulting in insufficient safety risk control in fracturing operations. Summary of the Invention

[0006] To overcome the aforementioned deficiencies of the prior art, embodiments of the present invention provide a tracer-based fracturing fracture identification and prediction system and method to address the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a tracer-based fracturing fracture identification and prediction system, comprising:

[0008] Tracer injection module: Used to inject tracers into fracturing fluid, inject fracturing fluid from the wellbore through the target formation, and collect fracturing operation data during fracturing fluid injection.

[0009] Tracer injection optimization module: It is used to calculate the fracturing operation safety control index during fracturing operation based on fracturing operation data during fracturing fluid injection, and optimize the tracer injection strategy.

[0010] The tracer fracture flow path acquisition module is used to acquire flow path monitoring data of the target formation injected from the wellbore every t time intervals. The flow path monitoring data includes fracture coordinate data acquisition unit and fracture propagation data acquisition unit.

[0011] The fracturing fracture propagation stability analysis module calculates the fracture propagation stability early warning index when fracturing fluid is injected into the target formation based on the fracture coordinate data collected by the fracture coordinate data acquisition unit, and provides early warning of fracturing fracture propagation stability.

[0012] Fracturing fracture propagation anomaly assessment module: Based on the fracture propagation data collected by the fracture propagation data acquisition unit, and based on the entropy surge theory, the prediction coefficient of fracture propagation anomaly in the target formation injected with fracturing fluid from the wellbore is calculated for each time period.

[0013] The fracturing fracture anomaly prediction and response module is used to obtain the fracture propagation anomaly prediction coefficient of the target formation injected with fracturing fluid from the wellbore in each time period, compare it with the preset fracture propagation anomaly prediction coefficient, and process it.

[0014] Preferably, the tracer is environmentally friendly, highly stable, and detectable, and can be uniformly distributed during fracturing and enter the fracture with the fracturing fluid;

[0015] The fracturing operation data includes the initial concentration of the tracer, the injection rate of the fracturing fluid, and the formation pressure.

[0016] Preferably, the tracer injection optimization module specifically comprises:

[0017] S31: The formula for calculating the fracturing operation safety control index is as follows:

[0018]

[0019] Where ω represents the safety control index for fracturing operations, qh represents the initial concentration of the tracer, and QH 预 QV represents the preset initial concentration of the tracer, and qv represents the fracturing fluid injection rate. 预 QP represents the preset fracturing fluid injection rate, and qp represents the formation pressure. 预 This is expressed as the preset formation pressure;

[0020] S32: Obtain the fracturing operation safety control index during fracturing fluid injection and compare it with the fracturing operation safety control index warning range. If the fracturing operation safety control index is greater than or equal to the maximum value of the fracturing operation safety control index warning range, it indicates that the operation safety assessment during fracturing fluid injection is within the safe range, and construction is allowed to continue. If the fracturing operation safety control index is less than the maximum value of the fracturing operation safety control index warning range but greater than or equal to the minimum value of the fracturing operation safety control index warning range, it indicates that the operation parameters during fracturing fluid injection need to be adjusted, and the operation safety assessment is within the warning range. If the fracturing operation safety control index is less than the minimum value of the fracturing operation safety control index warning range, it indicates that the operation safety assessment during fracturing fluid injection is within the dangerous range, and the operation should be stopped immediately.

[0021] S33: When the fracturing operation safety control index is less than the maximum value of the fracturing operation safety control index warning range, but greater than or equal to the minimum value of the fracturing operation safety control index warning range, the fracturing operation data adjustment strategy is to optimize 50% QH during fracturing fluid injection. 预 <qh≤70%QH 预 Optimize the fracturing fluid injection process to ensure qv ≤ 80% QV 预 Monitoring the qp during fracturing fluid injection: <70% QP 预 The priority for adjusting fracturing operation data is: formation pressure > fracturing fluid injection rate > initial tracer concentration.

[0022] Preferably, the tracer crack flow path acquisition module specifically comprises:

[0023] Fracture coordinate data acquisition unit: Every t time interval, it acquires the fracture location (x, y, t) of the target formation where fracturing fluid is injected from the wellbore. i y i ), where i = 1, 2, ..., n, and i represents the number of the i-th sub-time period;

[0024] Fracture propagation data acquisition unit: Every t time interval, it acquires the fracture propagation direction, fracture propagation length, and fracture propagation width of the target formation as fracturing fluid is injected from the wellbore, and labels them as σ. i ,kh i km i .

[0025] Preferably, the fracturing fracture propagation stability analysis module specifically comprises:

[0026] S51: Calculate the spatial displacement of crack propagation in each time period based on the crack location:

[0027]

[0028] Among them, D iLet x represent the spatial displacement of crack propagation in the i-th sub-period. i Let x be the crack x-axis coordinate of the i-th sub-time period, and y be the crack y-axis coordinate of i Let x represent the crack y-axis coordinate in the i-th sub-time period. i+1 Represented as the crack x-axis coordinate in the (i+1)th sub-time period, y i+1 This is represented by the crack's y-axis coordinate in the (i+1)th sub-time period;

[0029] S52: The formula for calculating the crack propagation stability early warning index is as follows:

[0030]

[0031] Where α represents the crack propagation stability early warning index, and n represents the number of sub-time periods;

[0032] S53: Set the preset crack propagation stability early warning index, the formula is:

[0033]

[0034] Where, α 预 D represents the preset crack propagation stability early warning index. max D represents the maximum spatial displacement of the crack propagation. min This represents the minimum spatial displacement during crack propagation;

[0035] S54: Obtain the fracture propagation stability warning index when fracturing fluid is injected into the target formation from the wellbore, and compare it with the preset fracture propagation stability warning index. If the fracture propagation stability warning index is greater than the preset fracture propagation stability warning index, it indicates that the fracturing fracture propagation behavior during the injection of fracturing fluid is abnormal, and an abnormal fracturing fracture propagation stability warning is immediately issued. Conversely, it indicates that the fracturing fracture propagation behavior during the injection of fracturing fluid is safe.

[0036] Preferably, the formula for calculating the crack propagation anomaly prediction coefficient is as follows:

[0037] β i =KS i ×JS i +max(0,MC) i -MH warn )

[0038] Where, β i Let KS be the crack propagation anomaly prediction coefficient for the i-th sub-period. i Let JS represent the crack entropy change rate in the i-th sub-time period. i Let MC represent the crack entropy change acceleration in the i-th sub-time period. iLet MH represent the intensity of the crack propagation anomaly risk in the i-th sub-period. warn This represents the warning threshold for the intensity of abnormal risk of crack propagation.

[0039] Preferably, the crack propagation anomaly prediction coefficient is specifically:

[0040] S71: Normalizing the crack propagation direction, crack propagation length, and crack propagation width yields:

[0041]

[0042] in, This is represented by the normalized value of the crack propagation direction in the i-th sub-time period. This is represented as the normalized value of the crack propagation length in the i-th sub-time period. Let σ be the normalized value of the crack propagation width in the i-th sub-time period. i Let σ represent the crack propagation direction in the i-th sub-time period. 预 Indicated as the preset crack propagation direction, σ max The maximum value in the direction of crack propagation is represented by kh. i Let kh represent the crack propagation length in the i-th sub-period. max Expressed as the maximum crack propagation length, in km. i Let the crack propagation width be represented as km in the i-th sub-time period. max This represents the maximum value of the crack propagation width;

[0043] S72: Calculate crack entropy:

[0044] S i =-∑ σ ∑ kh ∑ km p i (σ, kh, km)*log2p i (σ, kh, km)

[0045] Among them, S i Let p be the crack entropy in the i-th sub-time period. i (σ, kh, km) represents the probability distribution of the crack in the i-th sub-time period in terms of direction σ, length kh, and width km;

[0046] Calculate the crack entropy change rate:

[0047] Among them, KS i Let S be the crack entropy change rate in the i-th sub-time period. i-1 Let represent the crack entropy of the (i-1)th sub-period, and t represent the interval between each sub-period;

[0048] Calculate the entropy-change acceleration of the crack:

[0049] Among them, JS i Let KS be the crack entropy change acceleration in the i-th sub-time period. i-1 It is expressed as the crack entropy change rate in the (i-1)th sub-period;

[0050] S73: Calculate the intensity of the anomaly risk of crack propagation:

[0051] MC i =JS i ×exp(KS i )

[0052] Among them, MC i This represents the intensity of abnormal crack propagation risk in the i-th sub-period.

[0053] S74: If MC i ≤MH warn Then MC i -MH warn If the value is ≤0, then max(0, negative value) is reached, and β is output. i The result is KS i ×JS i +0, if MC i >MH warn Then MC i -MH warn If the value is greater than 0, then max(0, positive value) is used to output β. i The result is KS i ×JS i +(MC i -MH warn ).

[0054] Preferably, the fracturing fracture anomaly prediction and response module specifically comprises:

[0055] The prediction coefficients for fracture propagation anomalies in the target formation injected from the wellbore are obtained for each time period and compared with the preset prediction coefficients. If the prediction coefficients for fracture propagation anomalies in the target formation injected from the wellbore are greater than the preset prediction coefficients for a certain time period, it indicates that the degree of fracture anomaly in that time period is high. At this time, there is a safety hazard in the fracturing operation, and an anomaly warning should be issued immediately and the operation should be stopped. Conversely, if the prediction coefficients are less than the preset prediction coefficients, it indicates that the fracture propagation in that time period is stable and no intervention is required.

[0056] Preferably, a tracer-based method for identifying and predicting hydraulic fracturing fractures includes the following steps:

[0057] Step S01: Tracer Injection: This step involves injecting a tracer into the fracturing fluid, injecting the fracturing fluid through the target formation from the wellbore, and collecting fracturing operation data during the injection of the fracturing fluid.

[0058] Step S02: Tracer injection optimization: This step is used to calculate the fracturing operation safety control index based on fracturing operation data during fracturing fluid injection, and to optimize the tracer injection strategy.

[0059] Step S03: Tracer fracture flow path acquisition: This step is used to acquire flow path monitoring data of the target formation injected with fracturing fluid from the wellbore every t time intervals. Step S03: Tracer fracture flow path acquisition includes a fracture coordinate data acquisition sub-step and a fracture propagation data acquisition sub-step. The flow path monitoring data includes fracture coordinate data and fracture propagation data.

[0060] Step S04: Fracturing fracture propagation stability analysis: This step receives the flow path monitoring data transmitted from the tracer fracture flow path acquisition step, calculates the fracture propagation stability early warning index when fracturing fluid is injected into the target formation from the wellbore based on the fracture coordinate data acquisition sub-step, and performs fracturing fracture propagation stability early warning.

[0061] Step S05: Fracturing fracture propagation anomaly assessment: This step is used to receive the flow path monitoring data transmitted from the tracer fracture flow path acquisition step, and to calculate the fracture propagation anomaly prediction coefficient of the target formation injected with fracturing fluid from the wellbore for each time period based on the fracture propagation data acquisition sub-step and the entropy surge theory.

[0062] Step S06: Fracturing fracture anomaly prediction response: This step is used to obtain the fracture propagation anomaly prediction coefficient of the target formation injected with fracturing fluid from the wellbore in each time period, compare it with the preset fracture propagation anomaly prediction coefficient, and process it.

[0063] The technical effects and advantages of this invention are as follows:

[0064] 1. This invention provides a tracer-based fracturing fracture identification and prediction system and method. By collecting fracturing operation data during fracturing fluid injection, a fracturing operation safety control index is calculated. When the fracturing operation safety control index is less than the maximum value of the fracturing operation safety control index warning interval, but greater than or equal to the minimum value of the fracturing operation safety control index warning interval, the fracturing operation data adjustment strategy is to optimize the 50% QH during fracturing fluid injection. 预 <qh≤70%QH 预 Optimize the fracturing fluid injection process to ensure qv ≤ 80% QV 预 Monitoring the qp during fracturing fluid injection: <70% QP 预In fracturing operations, by dynamically calculating the safety control index and combining it with real-time data and early warning mechanisms, the tracer injection strategy can be scientifically adjusted to achieve a balance between safety and operational efficiency.

[0065] 2. This invention provides a tracer-based fracturing fracture identification and prediction system and method. By acquiring flow path monitoring data of fracturing fluid injected into the wellbore at every t time interval, and calculating a fracture propagation stability early warning index based on fracture coordinate data acquired by a fracture coordinate data acquisition unit, the system compares this index with a preset fracture propagation stability early warning index. If the index is greater than the preset index, it indicates an abnormality in fracture propagation behavior during fracturing fluid injection, and an immediate fracturing fracture propagation stability anomaly warning is issued. Conversely, if the index is less than the preset index, it indicates safe fracture propagation behavior. By dynamically monitoring fracture coordinate data in real time and providing early warnings of fracture propagation behavior stability, operational safety is improved. The system also provides a fracture propagation stability early warning index based on data acquired by the fracture propagation data acquisition unit. Extended data, based on the theory of entropy surge, calculates the anomaly prediction coefficient of fracture propagation anomaly in the target formation injected from the wellbore for each time period. Compare this coefficient with the preset anomaly prediction coefficient. If the anomaly prediction coefficient of fracture propagation anomaly in the target formation injected from the wellbore for a certain time period is greater than the preset anomaly prediction coefficient, it indicates that the degree of fracture anomaly in that time period is high. At this time, there is a safety hazard in fracturing operations, and an anomaly warning should be issued immediately and operations should be stopped. Conversely, it indicates that the fracture propagation in that time period is stable and no intervention is required. Through the coupled calculation of fracture entropy change rate, fracture entropy change acceleration, and fracture propagation anomaly risk intensity, the dynamic changes in the direction, length, and width of fracture propagation are transformed into a single anomaly coefficient. Combined with an adaptive warning threshold, the risk value of fracture propagation is quantified, avoiding one-sided judgment and achieving accurate fracture anomaly warning and response in fracturing operations. Attached Figure Description

[0066] Figure 1 This is a schematic diagram of the structure of a tracer-based fracturing fracture identification and prediction system according to the present invention.

[0067] Figure 2 This is a schematic diagram of the tracer crack flow path acquisition module of the present invention.

[0068] Figure 3 This is a schematic flowchart of a tracer-based fracturing fracture identification and prediction method according to the present invention. Detailed Implementation

[0069] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0070] Please see Figure 1 As shown, the present invention provides a tracer-based fracturing fracture identification and prediction system, including a tracer injection module, a tracer injection optimization module, a tracer fracture flow path acquisition module, a fracturing fracture propagation stability analysis module, a fracturing fracture propagation anomaly assessment module, and a fracturing fracture anomaly prediction and response module.

[0071] The tracer injection module is connected to the tracer injection optimization module, the tracer injection optimization module is connected to the tracer fracture flow path acquisition module, the tracer fracture flow path acquisition module is connected to the fracturing fracture propagation stability analysis module and the fracturing fracture propagation anomaly assessment module, and the fracturing fracture propagation anomaly assessment module is connected to the fracturing fracture anomaly prediction and response module.

[0072] The tracer injection module is used to inject tracers into fracturing fluid, inject fracturing fluid from the wellbore through the target formation, and collect fracturing operation data during fracturing fluid injection.

[0073] In one possible design, the tracer is environmentally friendly, highly stable, and detectable, and can be uniformly distributed during fracturing and enter the fracture with the fracturing fluid.

[0074] In one possible design, the fracturing operation data includes the initial concentration of the tracer, the fracturing fluid injection rate, and the formation pressure.

[0075] The tracer injection optimization module is used to calculate the fracturing operation safety control index based on the fracturing operation data during fracturing fluid injection, and to optimize the tracer injection strategy.

[0076] In one possible design, the tracer injection optimization module specifically comprises:

[0077] S01: The formula for calculating the fracturing operation safety control index is as follows:

[0078]

[0079] Where ω represents the safety control index for fracturing operations, qh represents the initial concentration of the tracer, and QH 预 QV represents the preset initial concentration of the tracer, and qv represents the fracturing fluid injection rate. 预QP represents the preset fracturing fluid injection rate, and qp represents the formation pressure. 预 This is expressed as the preset formation pressure;

[0080] S02: Obtain the fracturing operation safety control index during fracturing fluid injection and compare it with the fracturing operation safety control index warning range. If the fracturing operation safety control index is greater than or equal to the maximum value of the fracturing operation safety control index warning range, it indicates that the operation safety assessment during fracturing fluid injection is within the safe range, and construction can continue. If the fracturing operation safety control index is less than the maximum value of the fracturing operation safety control index warning range but greater than or equal to the minimum value of the fracturing operation safety control index warning range, it indicates that the operation parameters during fracturing fluid injection need to be adjusted, and the operation safety assessment is within the warning range. If the fracturing operation safety control index is less than the minimum value of the fracturing operation safety control index warning range, it indicates that the operation safety assessment during fracturing fluid injection is within the dangerous range, and the operation should be stopped immediately.

[0081] S03: When the fracturing operation safety control index is less than the maximum value of the fracturing operation safety control index warning range, but greater than or equal to the minimum value of the fracturing operation safety control index warning range, the fracturing operation data adjustment strategy is to optimize 50% QH during fracturing fluid injection. 预 <qh≤70%QH 预 Optimize the fracturing fluid injection process to ensure qv ≤ 80% QV 预 Monitoring the qp during fracturing fluid injection: <70% QP 预 The priority for adjusting fracturing operation data is: formation pressure > fracturing fluid injection rate > initial tracer concentration.

[0082] The present invention provides another embodiment, as follows:

[0083] S01: If the initial concentration of the tracer during fracturing fluid injection is 80 ppm, the preset initial concentration of the tracer is 100 ppm, and the fracturing fluid injection rate is 12 m / s... 3 / min, the preset fracturing fluid injection rate is 20m 3 / min, formation pressure is 35MPa, preset formation pressure is 50MPa;

[0084] S02: The safety control index for fracturing operations is calculated as follows:

[0085]

[0086] S03: Set the early warning range of the fracturing operation safety control index to 0.3 to 0.7. Since ω < 0.3, it indicates that the safety assessment of the fracturing fluid injection operation is within the dangerous range, and the operation should be stopped immediately.

[0087] Please see Figure 2As shown, the tracer fracture flow path acquisition module is used to acquire flow path monitoring data of the target formation injected from the wellbore every t time intervals. The flow path monitoring data includes fracture coordinate data acquisition unit and fracture propagation data acquisition unit, and the flow path monitoring data includes fracture coordinate data and fracture propagation data.

[0088] In one possible design, the tracer crack flow path acquisition module specifically comprises:

[0089] Fracture coordinate data acquisition unit: Every t time interval, it acquires the fracture location (x, y, t) of the target formation where fracturing fluid is injected from the wellbore. i y i ), where i = 1, 2, ..., n, and i represents the number of the i-th sub-time period;

[0090] Fracture propagation data acquisition unit: Every t time interval, it acquires the fracture propagation direction, fracture propagation length, and fracture propagation width of the target formation as fracturing fluid is injected from the wellbore, and labels them as σ. i ,kh i km i .

[0091] The fracturing fracture propagation stability analysis module is used to receive flow path monitoring data transmitted by the tracer fracture flow path acquisition module, and calculate the fracture propagation stability early warning index when fracturing fluid is injected into the target formation from the wellbore based on the fracture coordinate data acquired by the fracture coordinate data acquisition unit, and to provide early warning of fracturing fracture propagation stability.

[0092] In one possible design, the fracturing fracture propagation stability analysis module specifically comprises:

[0093] S01: Calculate the spatial displacement of crack propagation in each time period based on the crack location:

[0094]

[0095] Among them, D i Let x represent the spatial displacement of crack propagation in the i-th sub-period. i Let x be the crack x-axis coordinate of the i-th sub-time period, and y be the crack y-axis coordinate of i Let x represent the crack y-axis coordinate in the i-th sub-time period. i+1 Represented as the crack x-axis coordinate in the (i+1)th sub-time period, y i+1 This is represented by the crack's y-axis coordinate in the (i+1)th sub-time period;

[0096] S02: The formula for calculating the crack propagation stability early warning index is as follows:

[0097]

[0098] Where α represents the crack propagation stability early warning index, and n represents the number of sub-time periods;

[0099] S03: Set the preset crack propagation stability early warning index, the formula is:

[0100]

[0101] Where, α 预 D represents the preset crack propagation stability early warning index. max D represents the maximum spatial displacement of the crack propagation. min This represents the minimum spatial displacement during crack propagation;

[0102] The fracture propagation stability warning index of the target formation when fracturing fluid is injected into the wellbore is obtained and compared with the preset fracture propagation stability warning index. If the fracture propagation stability warning index is greater than the preset fracture propagation stability warning index, it indicates that the fracturing fracture propagation behavior during the injection of fracturing fluid is abnormal, and an abnormal fracturing fracture propagation stability warning is immediately issued. Conversely, if the index is less than the preset index, it indicates that the fracturing fracture propagation behavior during the injection of fracturing fluid is safe.

[0103] The fracturing fracture propagation anomaly assessment module is used to receive flow path monitoring data transmitted by the tracer fracture flow path acquisition module, and calculate the fracture propagation anomaly prediction coefficient of the target formation injected with fracturing fluid from the wellbore for each time period based on the fracture propagation data acquired by the fracture propagation data acquisition unit and the entropy surge theory.

[0104] In one possible design, the fracturing fracture propagation anomaly assessment module specifically comprises:

[0105] S01: Normalizing the crack propagation direction, crack propagation length, and crack propagation width yields:

[0106]

[0107] in, This is represented by the normalized value of the crack propagation direction in the i-th sub-time period. This is represented as the normalized value of the crack propagation length in the i-th sub-time period. Let σ be the normalized value of the crack propagation width in the i-th sub-time period. i Let σ represent the crack propagation direction in the i-th sub-time period. 预 Indicated as the preset crack propagation direction, σ max The maximum value in the direction of crack propagation is represented by kh. i Let kh represent the crack propagation length in the i-th sub-period. maxExpressed as the maximum crack propagation length, in km. i Let the crack propagation width be represented as km in the i-th sub-time period. max This represents the maximum value of the crack propagation width;

[0108] S02: Calculate crack entropy:

[0109] S i =-∑ σ ∑ kh ∑ km p i (σ, kh, km)*log2p i (σ, kh, km)

[0110] Among them, S i Let p be the crack entropy in the i-th sub-time period. i (σ, kh, km) represents the probability distribution of the crack in the i-th sub-time period in terms of direction σ, length kh, and width km;

[0111] Specifically, the higher the crack entropy value, the more unpredictable the crack propagation (such as sudden changes in direction, sudden increases in length, and oscillations in width); when the crack entropy value decreases, the crack propagation becomes more stable.

[0112] Calculate the crack entropy change rate:

[0113] Among them, KS i Let S be the crack entropy change rate in the i-th sub-time period. i-1 Let represent the crack entropy of the (i-1)th sub-period, and t represent the interval between each sub-period;

[0114] Calculate the entropy-change acceleration of the crack:

[0115] Among them, JS i Let KS be the crack entropy change acceleration in the i-th sub-time period. i-1 It is expressed as the crack entropy change rate in the (i-1)th sub-period;

[0116] Specifically, the higher the crack entropy change acceleration, the more unpredictable the crack propagation; when the crack entropy change acceleration decreases, the crack propagation becomes stable.

[0117] S03: Calculate the intensity of abnormal crack propagation risk:

[0118] MC i =JS i ×exp(KS i )

[0119] Among them, MC i This represents the intensity of abnormal crack propagation risk in the i-th sub-period.

[0120] Specifically, the greater the intensity of the abnormal crack propagation risk, the higher the risk of abnormal crack propagation.

[0121] S04: The formula for calculating the crack propagation anomaly prediction coefficient is as follows:

[0122] β i =KS i ×JS i +max(0,MC) i -MH warn )

[0123] Where, β i Let KS be the crack propagation anomaly prediction coefficient for the i-th sub-period. i Let JS represent the crack entropy change rate in the i-th sub-time period. i Let MC represent the crack entropy change acceleration in the i-th sub-time period. i Let MH represent the intensity of the crack propagation anomaly risk in the i-th sub-period. warn The warning threshold is represented as the intensity of abnormal crack propagation risk.

[0124] S05: If MC i ≤MH warn Then MC i -MH warn If the value is ≤0, then max(0, negative value) is reached, and β is output. i The result is KS i ×JS i +0, if MC i >MH warn Then MC i -MH warn If the value is greater than 0, then max(0, positive value) is used to output β. i The result is KS i ×JS i +(MC i -MH warn ).

[0125] In this embodiment, it should be specifically noted that the warning threshold for the abnormal risk intensity of crack propagation is as follows:

[0126] S01: Based on the historical anomaly risk intensity of crack propagation, obtain the mean and standard deviation of the anomaly risk intensity of crack propagation, ΔMC and μ;

[0127] S01: The formula for calculating the early warning threshold of the abnormal risk intensity of crack propagation is: MH warn =△MH+2μ

[0128] Among them, MH warndenoted as the warning threshold for the abnormal risk intensity of crack propagation, △MC represents the mean of the abnormal risk intensity of crack propagation, and μ represents the standard deviation of the abnormal risk intensity of crack propagation.

[0129] The fracturing fracture anomaly prediction response module is used to obtain the fracture propagation anomaly prediction coefficient of the target formation injected with fracturing fluid from the wellbore in each time period, compare it with the preset fracture propagation anomaly prediction coefficient, and process it.

[0130] In one possible design, the fracturing fracture anomaly prediction and response module specifically comprises:

[0131] The prediction coefficients for fracture propagation anomalies in the target formation injected from the wellbore are obtained for each time period and compared with the preset prediction coefficients. If the prediction coefficients for fracture propagation anomalies in the target formation injected from the wellbore are greater than the preset prediction coefficients for a certain time period, it indicates that the degree of fracture anomaly in that time period is high. At this time, there is a safety hazard in the fracturing operation, and an anomaly warning should be issued immediately and the operation should be stopped. Conversely, if the prediction coefficients are less than the preset prediction coefficients, it indicates that the fracture propagation in that time period is stable and no intervention is required.

[0132] Please see Figure 3 As shown, this invention provides a tracer-based method for identifying and predicting hydraulic fracturing fractures, comprising the following steps:

[0133] Step S01: Tracer Injection: This step involves injecting a tracer into the fracturing fluid, injecting the fracturing fluid through the target formation from the wellbore, and collecting fracturing operation data during the injection of the fracturing fluid.

[0134] Step S02: Tracer injection optimization: This step is used to calculate the fracturing operation safety control index based on fracturing operation data during fracturing fluid injection, and to optimize the tracer injection strategy.

[0135] Step S03: Tracer fracture flow path acquisition: This step is used to acquire flow path monitoring data of the target formation injected with fracturing fluid from the wellbore every t time intervals. Step S03: Tracer fracture flow path acquisition includes a fracture coordinate data acquisition sub-step and a fracture propagation data acquisition sub-step. The flow path monitoring data includes fracture coordinate data and fracture propagation data.

[0136] Step S04: Fracturing fracture propagation stability analysis: This step receives the flow path monitoring data transmitted from the tracer fracture flow path acquisition step, calculates the fracture propagation stability early warning index when fracturing fluid is injected into the target formation from the wellbore based on the fracture coordinate data acquisition sub-step, and performs fracturing fracture propagation stability early warning.

[0137] Step S05: Fracturing fracture propagation anomaly assessment: This step is used to receive the flow path monitoring data transmitted from the tracer fracture flow path acquisition step, and to calculate the fracture propagation anomaly prediction coefficient of the target formation injected with fracturing fluid from the wellbore for each time period based on the fracture propagation data acquisition sub-step and the entropy surge theory.

[0138] Step S06: Fracturing fracture anomaly prediction response: This step is used to obtain the fracture propagation anomaly prediction coefficient of the target formation injected with fracturing fluid from the wellbore in each time period, compare it with the preset fracture propagation anomaly prediction coefficient, and process it.

[0139] In this embodiment, it should be specifically noted that the present invention calculates the fracturing operation safety control index by collecting fracturing operation data during fracturing fluid injection. When the fracturing operation safety control index is less than the maximum value of the fracturing operation safety control index warning interval, but greater than or equal to the minimum value of the fracturing operation safety control index warning interval, the fracturing operation data adjustment strategy is to optimize 50% QH during fracturing fluid injection. 预 <qh≤70%QH 预 Optimize the fracturing fluid injection process to ensure qv ≤ 80% QV 预 Monitoring the qp during fracturing fluid injection: <70% QP 预 In fracturing operations, by dynamically calculating the safety control index and combining it with real-time data and early warning mechanisms, the tracer injection strategy can be scientifically adjusted to achieve a balance between safety and operational efficiency.

[0140] This invention acquires flow path monitoring data of fracturing fluid injected into the target formation from the wellbore at t-time intervals. Based on the fracture coordinate data collected by the fracture coordinate data acquisition unit, a fracture propagation stability early warning index is calculated for the target formation during fracturing fluid injection. This index is compared with a preset fracture propagation stability early warning index. If the index is greater than the preset index, it indicates an abnormality in the fracturing fracture propagation behavior during injection, and an immediate fracturing fracture propagation stability anomaly warning is issued. Conversely, if the index is less than the preset index, it indicates safe fracturing fracture propagation behavior. By dynamically monitoring fracture coordinate data in real time and providing early warning of fracture propagation behavior stability, operational safety is improved. Based on the fracture propagation data collected by the fracture propagation data acquisition unit, and using the entropy surge theory... The system calculates the anomaly prediction coefficient for fracture propagation anomaly in the target formation injected from the wellbore for each time period. This coefficient is then compared with a preset anomaly prediction coefficient. If the anomaly prediction coefficient for fracture propagation anomaly in the target formation injected from the wellbore for a certain time period is greater than the preset coefficient, it indicates a high degree of fracture anomaly in that time period. In this case, there is a safety hazard in fracturing operations, and an anomaly warning should be issued immediately and operations should be stopped. Conversely, if the coefficient is less than the preset coefficient, it indicates that the fracture propagation in that time period is stable and no intervention is required. By coupling the calculation of fracture entropy change rate, fracture entropy change acceleration, and fracture propagation anomaly risk intensity, the dynamic changes in the direction, length, and width of fracture propagation are transformed into a single anomaly coefficient. Combined with an adaptive warning threshold, the risk value of fracture propagation is quantified, avoiding one-sided judgments and achieving accurate fracture anomaly warning and response for fracturing operations.

[0141] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A tracer-based fracturing fracture identification and prediction system, characterized in that, include: Tracer injection module: used to inject tracers into fracturing fluid, inject fracturing fluid from the wellbore through the target formation, and collect fracturing operation data during fracturing fluid injection; Tracer injection optimization module: It is used to calculate the fracturing operation safety control index during fracturing operation based on fracturing operation data during fracturing fluid injection, and optimize the tracer injection strategy; The tracer fracture flow path acquisition module is used to acquire flow path monitoring data of the target formation injected from the wellbore every t time intervals. The flow path monitoring data includes a fracture coordinate data acquisition unit and a fracture propagation data acquisition unit. The fracturing fracture propagation stability analysis module calculates the fracture propagation stability early warning index when fracturing fluid is injected into the target formation from the wellbore based on the fracture coordinate data collected by the fracture coordinate data acquisition unit, and provides early warning of fracturing fracture propagation stability. Fracturing fracture propagation anomaly assessment module: Based on the fracture propagation data collected by the fracture propagation data acquisition unit, and based on the entropy surge theory, the prediction coefficient of fracture propagation anomaly when fracturing fluid is injected into the wellbore in the target formation at each time period is calculated. Fracturing fracture anomaly prediction response module: used to obtain the fracture propagation anomaly prediction coefficient of the target formation injected with fracturing fluid from the wellbore in each time period, compare it with the preset fracture propagation anomaly prediction coefficient, and process it. The formula for calculating the crack propagation anomaly prediction coefficient is as follows: in, Let be the crack propagation anomaly prediction coefficient for the i-th sub-period. Let be the crack entropy change rate in the i-th sub-time period. Let the crack entropy change acceleration be expressed as the acceleration during the i-th sub-time period. This represents the intensity of the crack propagation anomaly risk in the i-th sub-period. This represents the warning threshold for the intensity of abnormal risk of crack propagation.

2. The tracer-based fracturing fracture identification and prediction system according to claim 1, characterized in that: The tracer is environmentally friendly, highly stable, and detectable, and can be uniformly distributed during fracturing and enter the fracture with the fracturing fluid. The fracturing operation data includes the initial concentration of the tracer, the injection rate of the fracturing fluid, and the formation pressure.

3. The tracer-based fracturing fracture identification and prediction system according to claim 1, characterized in that: The tracer injection optimization module specifically comprises: S31: The formula for calculating the fracturing operation safety control index is as follows: in, The index represents the safety control index for fracturing operations, and qh represents the initial concentration of the tracer. q represents the preset initial concentration of the tracer, and qv represents the fracturing fluid injection rate. qp represents the preset fracturing fluid injection rate, and qp represents the formation pressure. This is expressed as the preset formation pressure; S32: Obtain the fracturing operation safety control index during fracturing fluid injection and compare it with the fracturing operation safety control index warning range. If the fracturing operation safety control index is greater than or equal to the maximum value of the fracturing operation safety control index warning range, it indicates that the operation safety assessment during fracturing fluid injection is within the safe range, and construction is allowed to continue. If the fracturing operation safety control index is less than the maximum value of the fracturing operation safety control index warning range but greater than or equal to the minimum value of the fracturing operation safety control index warning range, it indicates that the operation parameters during fracturing fluid injection need to be adjusted, and the operation safety assessment is within the warning range. If the fracturing operation safety control index is less than the minimum value of the fracturing operation safety control index warning range, it indicates that the operation safety assessment during fracturing fluid injection is within the dangerous range, and the operation should be stopped immediately. S33: When the fracturing operation safety control index is less than the maximum value of the fracturing operation safety control index warning range, but greater than or equal to the minimum value of the fracturing operation safety control index warning range, the fracturing operation data adjustment strategy is to optimize the fracturing fluid injection... Optimize fracturing fluid injection Monitoring fracturing fluid injection The priority for adjusting fracturing operation data is: formation pressure > fracturing fluid injection rate > initial tracer concentration.

4. The tracer-based fracturing fracture identification and prediction system according to claim 1, characterized in that: The tracer crack flow path acquisition module is specifically as follows: Fracture coordinate data acquisition unit: Every t time interval, it acquires the location of fractures in the target formation where fracturing fluid is injected from the wellbore. , ), where i = 1, 2, ..., n, and i represents the number of the i-th sub-time period; Fracture propagation data acquisition unit: Every t time interval, it acquires the fracture propagation direction, fracture propagation length, and fracture propagation width of the target formation as fracturing fluid is injected from the wellbore, and marks them as follows: , , .

5. The tracer-based fracturing fracture identification and prediction system according to claim 1, characterized in that: The fracturing fracture propagation stability analysis module specifically includes: S51: Calculate the spatial displacement of crack propagation in each time period based on the crack location: in, Let represent the spatial displacement of crack propagation in the i-th sub-time period. This is represented by the crack x-axis coordinate in the i-th sub-time period. This represents the y-axis coordinate of the crack in the i-th sub-time period. This is represented by the crack x-axis coordinate in the (i+1)th sub-time period. This is represented by the crack's y-axis coordinate in the (i+1)th sub-time period; S52: The formula for calculating the crack propagation stability early warning index is as follows: in, This is represented as the crack propagation stability early warning index, where n represents the number of sub-periods; S53: Set the preset crack propagation stability early warning index, the formula is: in, This is represented as a preset crack propagation stability early warning index. This represents the maximum spatial displacement during crack propagation. This represents the minimum spatial displacement during crack propagation; S54: Obtain the fracture propagation stability warning index when fracturing fluid is injected into the target formation from the wellbore, and compare it with the preset fracture propagation stability warning index. If the fracture propagation stability warning index is greater than the preset fracture propagation stability warning index, it indicates that the fracturing fracture propagation behavior during the injection of fracturing fluid is abnormal, and an abnormal fracturing fracture propagation stability warning is immediately issued. Conversely, it indicates that the fracturing fracture propagation behavior during the injection of fracturing fluid is safe.

6. The tracer-based fracturing fracture identification and prediction system according to claim 1, characterized in that: The specific prediction coefficient for crack propagation anomaly is: S71: Normalizing the crack propagation direction, crack propagation length, and crack propagation width yields: ， ， in, This is represented by the normalized value of the crack propagation direction in the i-th sub-time period. This is represented as the normalized value of the crack propagation length in the i-th sub-time period. This is represented as the normalized value of the crack propagation width in the i-th sub-time period. This represents the crack propagation direction in the i-th sub-time period. This represents the preset crack propagation direction. This represents the maximum value in the direction of crack propagation. Let represent the crack propagation length in the i-th sub-time period. This represents the maximum crack propagation length. Let represent the crack propagation width in the i-th sub-time period. This represents the maximum value of the crack propagation width; S72: Calculate crack entropy: in, Let the crack entropy be represented as the i-th sub-time period. The crack in the i-th sub-time period is represented by the direction. The probability distribution of length kh and width km; Calculate the crack entropy change rate: in, Let represent the crack entropy of the (i-1)th sub-period, and t represent the interval between each sub-period; Calculate the entropy-change acceleration of the crack: in, It is expressed as the crack entropy change rate in the (i-1)th sub-period; S73: Calculate the intensity of the anomaly risk of crack propagation: ； S74: If ,but ,at this time Output The result is ,like ,but ,at this time Output The result is .

7. The tracer-based fracturing fracture identification and prediction system according to claim 1, characterized in that: The fracturing fracture anomaly prediction and response module is specifically as follows: The prediction coefficients for fracture propagation anomalies in the target formation injected from the wellbore are obtained for each time period and compared with the preset prediction coefficients. If the prediction coefficients for fracture propagation anomalies in the target formation injected from the wellbore are greater than the preset prediction coefficients for a certain time period, it indicates that the degree of fracture anomaly in that time period is high. At this time, there is a safety hazard in the fracturing operation, and an anomaly warning should be issued immediately and the operation should be stopped. Conversely, if the prediction coefficients are less than the preset prediction coefficients, it indicates that the fracture propagation in that time period is stable and no intervention is required.

8. A tracer-based method for identifying and predicting fracturing fractures, using a tracer-based fracturing fracture identification and prediction system as described in any one of claims 1-7, characterized in that: Includes the following steps: Step S01: Tracer Injection: This step involves injecting a tracer into the fracturing fluid, injecting the fracturing fluid through the target formation from the wellbore, and collecting fracturing operation data during the injection of the fracturing fluid. Step S02: Tracer injection optimization: This step is used to calculate the fracturing operation safety control index based on fracturing operation data during fracturing fluid injection, and to optimize the tracer injection strategy. Step S03: Tracer fracture flow path acquisition: This step is used to acquire flow path monitoring data of the target formation injected with fracturing fluid from the wellbore every t time intervals. Step S03: Tracer fracture flow path acquisition includes a fracture coordinate data acquisition sub-step and a fracture propagation data acquisition sub-step. The flow path monitoring data includes fracture coordinate data and fracture propagation data. Step S04: Fracturing fracture propagation stability analysis: This step receives the flow path monitoring data transmitted from the tracer fracture flow path acquisition step, calculates the fracture propagation stability early warning index when fracturing fluid is injected into the target formation from the wellbore based on the fracture coordinate data acquisition sub-step, and performs fracturing fracture propagation stability early warning. Step S05: Fracturing fracture propagation anomaly assessment: This step is used to receive the flow path monitoring data transmitted from the tracer fracture flow path acquisition step, and to calculate the fracture propagation anomaly prediction coefficient of the target formation injected with fracturing fluid from the wellbore for each time period based on the fracture propagation data acquisition sub-step and the entropy surge theory. Step S06: Fracturing fracture anomaly prediction response: This step is used to obtain the fracture propagation anomaly prediction coefficient of the target formation injected with fracturing fluid from the wellbore in each time period, compare it with the preset fracture propagation anomaly prediction coefficient, and process it.

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