Near-borehole hydraulic fracturing crack evaluation method, device, equipment and medium

Abstract

The invention discloses a near-borehole hydraulic fracturing crack evaluation method and device, equipment and a medium, and relates to the technical field of petroleum and natural gas exploration and development, and the near-borehole hydraulic fracturing crack evaluation method comprises the following steps: processing scattering gamma-ray energy spectrum data; determining an initial stratum density and an initial photoelectric absorption cross section index value based on the processed data, and calculating an initial stratum fracture height and an initial stratum fracture position; constructing a cost function, performing optimization iteration on the cost function to obtain a target stratum density and a target photoelectric absorption cross section index value, and correcting the initial stratum fracture height and the initial stratum fracture position to obtain a target stratum fracture height and a target stratum fracture position; according to the near-borehole hydraulic fracturing crack evaluation method and device, the position of the stratum crack and parameters of the stratum crack can be accurately determined, the sensitivity of crack response is improved, the efficiency and accuracy of near-borehole hydraulic fracturing crack evaluation are improved, and the complexity of measurement before and after fracturing is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas exploration and development, and in particular to a near-wellbore hydraulic fracturing crack evaluation method, device, equipment and medium. Background Art

[0002] At present, the near-wellbore fracturing fracture diagnosis technologies mainly include acoustic-electric imaging logging, well temperature logging, radioactive tracer logging, and non-radioactive tracer logging based on pulsed neutron technology. Among them, acoustic-electric imaging logging and well temperature logging can only determine the location of fractures, and the accuracy is not high; radioactive tracer logging uses radioactive tracer elements as tracers to evaluate fracture parameters. The radioactive element tracers used have certain hazards to the environment and human body, and have been gradually abandoned; when non-radioactive tracer logging based on pulsed neutron technology is used for fracture evaluation, high thermal neutron capture cross-section elements will cause neutron self-shielding effect, which greatly reduces the response sensitivity of fractures. For larger fractures, it can only determine whether they exist, and cannot perform quantitative calculation of fracture parameters. At the same time, this method requires measurement once before and after fracturing.

[0003] As can be seen from the above, how to accurately determine the location and parameters of formation fractures, increase the sensitivity of fracture response, improve the efficiency and accuracy of near-wellbore hydraulic fracturing fracture evaluation, and reduce the complexity of measurements before and after fracturing are problems to be solved in this field. Summary of the invention

[0004] In view of this, the purpose of the present invention is to provide a near-wellbore hydraulic fracturing fracture evaluation method, device, equipment and medium, which can accurately determine the formation fracture location and formation fracture parameters, increase the sensitivity of fracture response, improve the efficiency and accuracy of near-wellbore hydraulic fracturing fracture evaluation, and reduce the complexity of measurement before and after fracturing. The specific scheme is as follows:

[0005] In a first aspect, the present application discloses a near-wellbore hydraulic fracturing fracture evaluation method, comprising:

[0006] Detecting formation fractures, and if proppant is detected in the formation fractures, performing energy spectrum measurement on the formation fractures to obtain scattered gamma energy spectra, and performing data processing on the scattered gamma energy spectra to obtain processed data;

[0007] Determine an initial formation density and an initial photoelectric absorption cross-section index value based on the processed data, and calculate an initial formation fracture height and an initial formation fracture position according to the initial formation density and the initial photoelectric absorption cross-section index value;

[0008] A cost function is constructed using the initial formation density and the initial photoelectric absorption cross-section index value, and the cost function is optimized and iterated to obtain a target formation density and a target photoelectric absorption cross-section index value, and the initial formation fracture height and the initial formation fracture position are corrected according to the target formation density and the target photoelectric absorption cross-section index value to obtain a target formation fracture height and a target formation fracture position;

[0009] A correlation between the target formation density and the target photoelectric absorption cross-section index value and the crack width is established, and the target formation crack width is calculated using the correlation relationship. Based on the target formation crack height, the target formation crack position and the target formation crack width, an evaluation of near-wellbore hydraulic fracturing cracks is achieved.

[0010] Optionally, performing energy spectrum measurement on the formation fracture to obtain each scattered gamma energy spectrum includes:

[0011] The stratum fractures are measured for scattered gamma energy spectra using a preset X-ray lithology density instrument to obtain scattered gamma energy spectra; wherein the X-ray lithology density instrument includes an X-ray tube and a gamma detector.

[0012] Optionally, performing data processing on each of the scattered gamma energy spectra to obtain processed data includes:

[0013] Each of the scattered gamma energy spectra is subjected to filtering and denoising processing to obtain the scattered gamma energy spectra after filtering and denoising processing, and then the scattered gamma energy spectra after filtering and denoising processing are divided into energy windows to obtain processed data.

[0014] Optionally, performing filtering and denoising processing on each of the scattered gamma energy spectra to obtain the scattered gamma energy spectra after filtering and denoising processing, and then performing energy window division on the scattered gamma energy spectra after filtering and denoising processing to obtain processed data, includes:

[0015] Using a Kalman filter algorithm to perform filtering and noise reduction processing on each of the scattered gamma energy spectra to obtain the scattered gamma energy spectra after filtering and noise reduction processing;

[0016] The scattered gamma energy spectrum after filtering and noise reduction is divided into energy windows according to a preset number of energy window divisions to obtain processed data.

[0017] Optionally, the calculating the initial formation fracture height and the initial formation fracture position according to the initial formation density and the initial photoelectric absorption cross-section index value includes:

[0018] Acquire actual formation density, and determine whether a density error value between the initial formation density and the actual formation density is greater than a preset error threshold;

[0019] If the density error value between the initial formation density and the actual formation density is greater than a preset error threshold, the initial formation fracture height and the initial formation fracture position are calculated based on the initial formation density and the initial photoelectric absorption cross-section index value.

[0020] Optionally, constructing a cost function using the initial formation density and the initial photoelectric absorption cross-section index value includes:

[0021] Constructing constraint conditions based on the initial formation density and the initial photoelectric absorption cross-section index value;

[0022] A nonlinear inversion method is used to eliminate the difference between the actual gap and the fracturing fluid information, and a cost function is constructed based on the constraint conditions.

[0023] Optionally, the optimizing and iterating the cost function to obtain a target formation density and a target photoelectric absorption cross-section index value includes:

[0024] The cost function is optimized by using the McQuarter method to obtain the optimized cost function;

[0025] The optimized cost function is iteratively inverted to obtain the target formation density and the target photoelectric absorption cross-section index value.

[0026] In a second aspect, the present application discloses a near-wellbore hydraulic fracturing fracture evaluation device, comprising:

[0027] An energy spectrum measurement and processing module is used to detect formation fractures. If proppant is detected in the formation fractures, energy spectrum measurement is performed on the formation fractures to obtain scattered gamma energy spectra, and data processing is performed on the scattered gamma energy spectra to obtain processed data.

[0028] A formation fracture height position determination module, used to determine an initial formation density and an initial photoelectric absorption cross-sectional index value based on the processed data, and calculate an initial formation fracture height and an initial formation fracture position according to the initial formation density and the initial photoelectric absorption cross-sectional index value;

[0029] A formation fracture height position correction module, used to construct a cost function using the initial formation density and the initial photoelectric absorption cross-section index value, optimize and iterate the cost function to obtain a target formation density and a target photoelectric absorption cross-section index value, and correct the initial formation fracture height and the initial formation fracture position according to the target formation density and the target photoelectric absorption cross-section index value to obtain a target formation fracture height and a target formation fracture position;

[0030] The near-wellbore hydraulic fracturing crack evaluation module is used to establish a correlation between the target formation density and the target photoelectric absorption cross-section index value and the crack width, calculate the target formation crack width using the correlation, and evaluate the near-wellbore hydraulic fracturing crack based on the target formation crack height, the target formation crack position and the target formation crack width.

[0031] In a third aspect, the present application discloses an electronic device, including:

[0032] Memory, used to store computer programs;

[0033] The processor is used to execute the computer program to implement the aforementioned near-wellbore hydraulic fracturing fracture evaluation method.

[0034] In a fourth aspect, the present application discloses a computer storage medium for storing a computer program; wherein, when the computer program is executed by a processor, the steps of the aforementioned near-wellbore hydraulic fracturing fracture evaluation method are implemented.

[0035] It can be seen that the present application provides a near-wellbore hydraulic fracturing fracture evaluation method, including detecting formation fractures, if it is detected that there is a proppant in the formation fracture, then performing energy spectrum measurement on the formation fracture to obtain each scattered gamma energy spectrum, performing data processing on each scattered gamma energy spectrum to obtain processed data; based on the processed data, determining the initial formation density and the initial photoelectric absorption cross-section index value, and calculating the initial formation fracture height and the initial formation fracture position according to the initial formation density and the initial photoelectric absorption cross-section index value; using the initial formation density and the initial photoelectric absorption cross-section index value to construct a cost function, The cost function is optimized and iterated to obtain a target formation density and a target photoelectric absorption cross-section index value, and the initial formation fracture height and the initial formation fracture position are corrected according to the target formation density and the target photoelectric absorption cross-section index value to obtain a target formation fracture height and a target formation fracture position; a correlation relationship between the target formation density and the target photoelectric absorption cross-section index value and the fracture width is established, and the target formation fracture width is calculated using the correlation relationship, and an evaluation of near-wellbore hydraulic fracturing fractures is achieved based on the target formation fracture height, the target formation fracture position and the target formation fracture width. The present application utilizes the photoelectric effect and Compton effect on the proppant to realize the energy spectrum measurement of the formation fracture, thereby obtaining the scattered gamma energy spectrum, and obtains the initial bottom fracture height and the formation fracture position by data processing of the scattered gamma energy spectrum, and realizes the correction of the initial bottom fracture height and the formation fracture position by optimizing and iterating the cost function, and obtains the target formation fracture height and the target formation fracture position, thereby realizing the accurate determination of the formation fracture position and the formation fracture parameters, and increasing the sensitivity of the fracture response, and calculating the target formation fracture width by establishing the correlation between the target formation density and the target photoelectric absorption cross-section index value and the fracture width, so as to realize the evaluation of the near-wellbore hydraulic fracturing fracture, which can improve the efficiency and accuracy of the near-wellbore hydraulic fracturing fracture evaluation and reduce the complexity of the measurement before and after fracturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0037] Figure 1 A flow chart of a near-wellbore hydraulic fracturing fracture evaluation method disclosed in this application;

[0038] Figure 2 A schematic diagram of an X-ray density crack measurement disclosed in this application;

[0039] Figure 3 A flow chart of a near-wellbore hydraulic fracturing fracture evaluation method disclosed in this application;

[0040] Figure 4 This is an example diagram of a scattered gamma energy spectrum response result disclosed in this application;

[0041] Figure 5 This is an example diagram of a response comparison between a theoretical density value and an actual density calculation disclosed in the present application;

[0042] Figure 6 This is a schematic diagram of the structure of a near-wellbore hydraulic fracturing fracture evaluation device disclosed in this application;

[0043] Figure 7 A structural diagram of an electronic device provided for this application. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] At present, the near-wellbore fracturing fracture diagnosis technologies mainly include acoustic and electrical imaging logging, well temperature logging, radioactive tracer logging, and non-radioactive tracer logging based on pulsed neutron technology. Among them, acoustic and electrical imaging logging and well temperature logging can only determine the location of fractures, and the accuracy is not high; radioactive tracer elements are used as tracers in radioactive tracer logging to evaluate fracture parameters. The radioactive element tracers used have certain hazards to the environment and human body, and have been gradually abandoned; when non-radioactive tracer logging based on pulsed neutron technology is used for fracture evaluation, high thermal neutron capture cross-section elements will cause neutron self-shielding effect, which greatly reduces the response sensitivity of fractures. For larger fractures, it can only be judged whether they exist, and the quantitative calculation of fracture parameters cannot be performed. At the same time, this method requires measurement once before and after fracturing. As can be seen from the above, how to accurately determine the location and parameters of formation fractures, increase the sensitivity of fracture response, improve the efficiency and accuracy of near-wellbore hydraulic fracturing fracture evaluation, and reduce the complexity of measurements before and after fracturing are problems to be solved in this field.

[0046] See also Figure 1 As shown, the embodiment of the present invention discloses a near-wellbore hydraulic fracturing fracture evaluation method, which may specifically include:

[0047] Step S11: Detecting formation fractures. If proppant is detected in the formation fractures, performing energy spectrum measurement on the formation fractures to obtain scattered gamma energy spectra, and performing data processing on the scattered gamma energy spectra to obtain processed data.

[0048] In this embodiment, formation fractures are detected. If proppant is detected in the formation fractures, a preset X-ray lithology density instrument is used to measure the scattered gamma energy spectrum of the formation fractures to obtain each scattered gamma energy spectrum; wherein the X-ray lithology density instrument includes an X-ray tube and a gamma detector, and then each of the scattered gamma energy spectra is processed to obtain processed data.

[0049] The data processing process is: filtering and denoising each of the scattered gamma energy spectra to obtain the scattered gamma energy spectra after filtering and denoising, and then dividing the scattered gamma energy spectra after filtering and denoising into energy windows to obtain processed data. Specifically, the Kalman filter algorithm is used to filter and denoise each of the scattered gamma energy spectra to obtain the scattered gamma energy spectra after filtering and denoising; the scattered gamma energy spectra after filtering and denoising are divided into energy windows according to a preset number of energy window divisions to obtain processed data. The number of energy window divisions is at least 5, that is, at least 5 energy windows are divided.

[0050] In this embodiment, by adding elements with Pe value (Photoelectric absorption Eoss-section index, high photoelectric absorption cross-section index value) as tracers in the fracturing proppant, the X-ray lithology density device is used to measure the post-fracture formation, and the high and low energy window counting are used to analyze the formation lithology and density changes to identify the proppant position, and then determine the parameters such as the fracture position, height, and width. The specific steps are as follows: (1) During the hydraulic fracturing process, special proppant containing high photoelectric absorption cross-section elements such as Ba (Barium) and Fe (Ferrum) is mixed in the fracturing fluid and pumped into the formation; (2) The scattered gamma energy spectrum information at different depths is measured using the X-ray lithology density instrument; (3) The scattered gamma energy spectrum measured by different detectors of the X-ray lithology density instrument is processed, and the processed data is obtained. Among them, the proppant is made of quartz sand or artificial ceramsite as the main raw material, mixed with BaSO4, FeS2 and other materials with high photoelectric absorption cross-section index and sintered; the X-ray lithology density instrument includes an X-ray source and at least two X-ray detectors. Among them, the schematic diagram of fracturing measurement of X-ray lithology density instrument is as follows Figure 2As shown in the figure, the X-ray lithology density instrument mainly includes an X-ray tube and at least two gamma detectors. Both the detectors and the X-ray source are designed with openings to improve the detection efficiency of gamma rays. During the measurement process, the X-ray lithology density instrument is measured close to the well wall. Figure 2 1 is the X-ray source, 2 is the X-ray source opening, 3 is the near detector opening, 4 is the fracturing crack filled with special proppant, 5 is the far detector opening, 6 is the far gamma detector, 7 is the near gamma detector, 8 is the parallel eye, and 9 is the formation.

[0051] Step S12: determining an initial formation density and an initial photoelectric absorption cross-section index value based on the processed data, and calculating an initial formation fracture height and an initial formation fracture position according to the initial formation density and the initial photoelectric absorption cross-section index value.

[0052] Step S13: construct a cost function using the initial formation density and the initial photoelectric absorption cross-section index value, optimize and iterate the cost function to obtain the target formation density and the target photoelectric absorption cross-section index value, and correct the initial formation fracture height and the initial formation fracture position according to the target formation density and the target photoelectric absorption cross-section index value to obtain the target formation fracture height and the target formation fracture position.

[0053] In this embodiment, a cost function is constructed using the initial formation density and the initial photoelectric absorption cross-section index value, and then the cost function is optimized using the McQuarter method to obtain the optimized cost function, and the optimized cost function is iteratively inverted to obtain the target formation density and the target photoelectric absorption cross-section index value, and then the initial formation fracture height and the initial formation fracture position are corrected according to the target formation density and the target photoelectric absorption cross-section index value to obtain the target formation fracture height and the target formation fracture position.

[0054] Specifically, the scattered gamma energy spectrum information of at least two detectors is used, and in the nonlinear inversion process, the LM (Levenberg-Marquardt) method is used to optimize the cost function, and then the formation density and Pe value are solved by iterative inversion.

[0055] Step S14: Establish a correlation between the target formation density and the target photoelectric absorption cross-section index value and the crack width, calculate the target formation crack width using the correlation, and evaluate the near-wellbore hydraulic fracturing cracks based on the target formation crack height, the target formation crack position and the target formation crack width.

[0056] In this embodiment, formation fractures are detected, and if proppant is detected in the formation fractures, energy spectrum measurement is performed on the formation fractures to obtain scattered gamma energy spectra, and data processing is performed on each scattered gamma energy spectrum to obtain processed data; initial formation density and initial photoelectric absorption cross-section index value are determined based on the processed data, and initial formation fracture height and initial formation fracture position are calculated according to the initial formation density and the initial photoelectric absorption cross-section index value; a cost function is constructed using the initial formation density and the initial photoelectric absorption cross-section index value, and the cost function is optimized Iterate to obtain a target formation density and a target photoelectric absorption cross-section index value, correct the initial formation fracture height and the initial formation fracture position according to the target formation density and the target photoelectric absorption cross-section index value to obtain a target formation fracture height and a target formation fracture position; establish a correlation between the target formation density and the target photoelectric absorption cross-section index value and the fracture width, calculate the target formation fracture width using the correlation, and evaluate the near-wellbore hydraulic fracturing fracture based on the target formation fracture height, the target formation fracture position and the target formation fracture width. The present application utilizes the photoelectric effect and Compton effect on the proppant to realize the energy spectrum measurement of the formation fracture, thereby obtaining the scattered gamma energy spectrum, and obtains the initial bottom fracture height and the formation fracture position by data processing of the scattered gamma energy spectrum, and realizes the correction of the initial bottom fracture height and the formation fracture position by optimizing and iterating the cost function, and obtains the target formation fracture height and the target formation fracture position, thereby realizing the accurate determination of the formation fracture position and the formation fracture parameters, and increasing the sensitivity of the fracture response, and calculating the target formation fracture width by establishing the correlation between the target formation density and the target photoelectric absorption cross-section index value and the fracture width, so as to realize the evaluation of the near-wellbore hydraulic fracturing fracture, which can improve the efficiency and accuracy of the near-wellbore hydraulic fracturing fracture evaluation and reduce the complexity of the measurement before and after fracturing.

[0057] See also Figure 3 As shown, the embodiment of the present invention discloses a near-wellbore hydraulic fracturing fracture evaluation method, which may specifically include:

[0058] Step S21: Detecting formation fractures. If proppant is detected in the formation fractures, performing energy spectrum measurement on the formation fractures to obtain scattered gamma energy spectra, and performing data processing on the scattered gamma energy spectra to obtain processed data.

[0059] Step S22: Determine the initial formation density and the initial photoelectric absorption cross-section index value based on the processed data, obtain the actual formation density, and determine whether the density error value between the initial formation density and the actual formation density is greater than a preset error threshold; if the density error value between the initial formation density and the actual formation density is greater than the preset error threshold, calculate the initial formation fracture height and the initial formation fracture position based on the initial formation density and the initial photoelectric absorption cross-section index value.

[0060] In this embodiment, an example of a scattered gamma spectrum is as follows: Figure 4 As shown, Figure 4 The scattered gamma spectrum response results measured by the detector when the crack width is 0 cm and 0.4 cm respectively. The scattered gamma spectrum measured by different detectors of the X-ray lithology density instrument is processed, and the scattered gamma spectrum filtering and noise reduction uses the Kalman filter algorithm to Figure 4 Taking the scattered gamma energy spectrum when the width of the medium crack is 0.4cm as an example, the scattered gamma energy spectrum is divided into 5 energy windows in the range of 0-0.25MeV, named W1, W2, W3, W4, and W5. The energy interval of each energy window is 0.05MeV, of which the high energy range is W3+W4 and the low energy range is W1. The mathematical relationship between the energy window count and the formation density in the high energy range is established, and the calculation formula is:

[0061] ρ=a0ln(Counts_W3+Counts_W4)+b0;

[0062] Among them, Counts_W3 and Counts_W4 are the gamma counts in energy windows W3 and W4. The light band absorption cross-section index Pe still uses the traditional high and low energy window count ratio, and the calculation formula is:

[0063]

[0064] Among them, a1 and b1 are constant coefficients, and Counts_W1 is the gamma count of energy window W1. The detector density calculated by the energy window method and the abnormal high value change of the photoelectric cross-section absorption index Pe are used to determine the position and height of the crack.

[0065] Step S23: constructing constraint conditions based on the initial formation density and the initial photoelectric absorption cross-section index value, using a nonlinear inversion method to eliminate differences between actual gaps and fracturing fluid information, and constructing a cost function based on the constraint conditions.

[0066] Step S24: Optimize and iterate the cost function to obtain the target formation density and the target photoelectric absorption cross-section index value, and correct the initial formation fracture height and the initial formation fracture position according to the target formation density and the target photoelectric absorption cross-section index value to obtain the target formation fracture height and the target formation fracture position.

[0067] Step S25: Establish a correlation between the target formation density and the target photoelectric absorption cross-section index value and the crack width, calculate the target formation crack width using the correlation, and evaluate the near-wellbore hydraulic fracturing cracks based on the target formation crack height, the target formation crack position and the target formation crack width.

[0068] In this embodiment, the actual gap and fracturing fluid information are used, and the nonlinear inversion method is adopted to eliminate the information difference effect of the actual gap and fracturing fluid information, so as to subsequently calculate the accurate target formation density and target photoelectric absorption cross-section index value, thereby accurately determining the relevant parameters such as the proppant, fracture position and fracture height. Among them, the actual gap and fracturing fluid information are used, and the nonlinear inversion method is adopted to eliminate the information difference effect of the actual gap and fracturing fluid information. During the inversion process, the relationship between the count in the detector energy window and the formation density, photoelectric cross-section absorption index, etc. can be described by the following formula:

[0069]

[0070] Among them, k1, k2, k3, k4, k5, k6 are constant coefficients, ρ is the formation density, unit is g / cm 3 , ρ s is the density of the interstitial fluid, in g / cm 3 , d s is the gap distance, in cm. The cost function constructed in the nonlinear inversion process is:

[0071]

[0072] Among them, ||·|| 2 represents the square of the L2 norm, ||W A ·e(p)|| 2 Based on The calculated detector density response vector S(p) and the measured gamma density measurement result d s The L2 norm of the difference between the two, that is, e(p) = S(p)-d s , p is the parameter vector to be inverted, including formation density, Pe, and gap. λ||W B·(p+p0)|| is the regularization term, which mainly prevents overfitting and suppresses the error caused by radioactive statistical fluctuations. p0 is the reference vector of the initial formation core characteristic parameters, λ is the regularization parameter, and W A and W B The LM method is used to process and iteratively calculate the cost function formula, and the mathematical relationship between the actual formation density and Pe result is established to achieve the quantitative calculation of the fracture width or density. Figure 5 This is the response of the theoretical density value to the actual density when the crack width increases from 0 cm to 2 cm. It can be clearly seen from the figure that when the crack is filled with special proppants containing BaSO4, the density value calculated by the detector is much larger than the actual density. The occurrence of density anomaly can realize the judgment of the crack and the quantitative calculation of the crack parameters can be realized through the established correlation relationship.

[0073] In this embodiment, formation fractures are detected, and if proppant is detected in the formation fractures, energy spectrum measurement is performed on the formation fractures to obtain scattered gamma energy spectra, and data processing is performed on each scattered gamma energy spectrum to obtain processed data; initial formation density and initial photoelectric absorption cross-section index value are determined based on the processed data, and initial formation fracture height and initial formation fracture position are calculated according to the initial formation density and the initial photoelectric absorption cross-section index value; a cost function is constructed using the initial formation density and the initial photoelectric absorption cross-section index value, and the cost function is optimized Iterate to obtain a target formation density and a target photoelectric absorption cross-section index value, correct the initial formation fracture height and the initial formation fracture position according to the target formation density and the target photoelectric absorption cross-section index value to obtain a target formation fracture height and a target formation fracture position; establish a correlation between the target formation density and the target photoelectric absorption cross-section index value and the fracture width, calculate the target formation fracture width using the correlation, and evaluate the near-wellbore hydraulic fracturing fracture based on the target formation fracture height, the target formation fracture position and the target formation fracture width. The present application utilizes the photoelectric effect and Compton effect on the proppant to realize the energy spectrum measurement of the formation fracture, thereby obtaining the scattered gamma energy spectrum, and obtains the initial bottom fracture height and the formation fracture position by data processing of the scattered gamma energy spectrum, and realizes the correction of the initial bottom fracture height and the formation fracture position by optimizing and iterating the cost function, and obtains the target formation fracture height and the target formation fracture position, thereby realizing the accurate determination of the formation fracture position and the formation fracture parameters, and increasing the sensitivity of the fracture response, and calculating the target formation fracture width by establishing the correlation between the target formation density and the target photoelectric absorption cross-section index value and the fracture width, so as to realize the evaluation of the near-wellbore hydraulic fracturing fracture, which can improve the efficiency and accuracy of the near-wellbore hydraulic fracturing fracture evaluation and reduce the complexity of the measurement before and after fracturing.

[0074] See also Figure 6 As shown, the embodiment of the present invention discloses a near-wellbore hydraulic fracturing fracture evaluation device, which may specifically include:

[0075] The energy spectrum measurement and processing module 11 is used to detect formation fractures. If proppant is detected in the formation fractures, the energy spectrum measurement is performed on the formation fractures to obtain scattered gamma energy spectra, and data processing is performed on the scattered gamma energy spectra to obtain processed data.

[0076] A formation fracture height position determination module 12, used to determine an initial formation density and an initial photoelectric absorption cross-sectional index value based on the processed data, and calculate an initial formation fracture height and an initial formation fracture position according to the initial formation density and the initial photoelectric absorption cross-sectional index value;

[0077] A formation fracture height position correction module 13 is used to construct a cost function using the initial formation density and the initial photoelectric absorption cross-section index value, optimize and iterate the cost function to obtain a target formation density and a target photoelectric absorption cross-section index value, and correct the initial formation fracture height and the initial formation fracture position according to the target formation density and the target photoelectric absorption cross-section index value to obtain a target formation fracture height and a target formation fracture position;

[0078] The near-wellbore hydraulic fracturing crack evaluation module 14 is used to establish a correlation between the target formation density and the target photoelectric absorption cross-section index value and the crack width, calculate the target formation crack width using the correlation, and evaluate the near-wellbore hydraulic fracturing crack based on the target formation crack height, the target formation crack position and the target formation crack width.

[0079] In this embodiment, formation fractures are detected, and if proppant is detected in the formation fractures, energy spectrum measurement is performed on the formation fractures to obtain scattered gamma energy spectra, and data processing is performed on each scattered gamma energy spectrum to obtain processed data; initial formation density and initial photoelectric absorption cross-section index value are determined based on the processed data, and initial formation fracture height and initial formation fracture position are calculated according to the initial formation density and the initial photoelectric absorption cross-section index value; a cost function is constructed using the initial formation density and the initial photoelectric absorption cross-section index value, and the cost function is optimized Iterate to obtain a target formation density and a target photoelectric absorption cross-section index value, correct the initial formation fracture height and the initial formation fracture position according to the target formation density and the target photoelectric absorption cross-section index value to obtain a target formation fracture height and a target formation fracture position; establish a correlation between the target formation density and the target photoelectric absorption cross-section index value and the fracture width, calculate the target formation fracture width using the correlation, and evaluate the near-wellbore hydraulic fracturing fracture based on the target formation fracture height, the target formation fracture position and the target formation fracture width. The present application utilizes the photoelectric effect and Compton effect on the proppant to realize the energy spectrum measurement of the formation fracture, thereby obtaining the scattered gamma energy spectrum, and obtains the initial bottom fracture height and the formation fracture position by data processing of the scattered gamma energy spectrum, and realizes the correction of the initial bottom fracture height and the formation fracture position by optimizing and iterating the cost function, and obtains the target formation fracture height and the target formation fracture position, thereby realizing the accurate determination of the formation fracture position and the formation fracture parameters, and increasing the sensitivity of the fracture response, and calculating the target formation fracture width by establishing the correlation between the target formation density and the target photoelectric absorption cross-section index value and the fracture width, so as to realize the evaluation of the near-wellbore hydraulic fracturing fracture, which can improve the efficiency and accuracy of the near-wellbore hydraulic fracturing fracture evaluation and reduce the complexity of the measurement before and after fracturing.

[0080] In some specific embodiments, the energy spectrum measurement processing module 11 may specifically include:

[0081] The scattered gamma spectrum measurement module is used to perform scattered gamma spectrum measurement on the formation fractures using a preset X-ray lithology density instrument to obtain scattered gamma spectrum; wherein the X-ray lithology density instrument includes an X-ray tube and a gamma detector.

[0082] In some specific embodiments, the energy spectrum measurement processing module 11 may specifically include:

[0083] The noise reduction processing and energy window division module is used to perform filtering and noise reduction processing on each of the scattered gamma energy spectra to obtain the scattered gamma energy spectrum after filtering and noise reduction processing, and then perform energy window division on the scattered gamma energy spectrum after filtering and noise reduction processing to obtain processed data.

[0084] In some specific embodiments, the energy spectrum measurement processing module 11 may specifically include:

[0085] A filtering and denoising processing module, used for performing filtering and denoising processing on each of the scattered gamma energy spectra using a Kalman filtering algorithm to obtain the scattered gamma energy spectra after filtering and denoising processing;

[0086] The energy window division module is used to perform energy window division on the scattered gamma energy spectrum after filtering and noise reduction processing according to a preset number of energy window divisions to obtain processed data.

[0087] In some specific embodiments, the formation fracture height position determination module 12 may specifically include:

[0088] A judgment module, used to obtain actual formation density and judge whether a density error value between the initial formation density and the actual formation density is greater than a preset error threshold;

[0089] The module for determining the height and position of initial formation fractures is used to calculate the height and position of initial formation fractures based on the initial formation density and the initial photoelectric absorption cross-section index value if the density error between the initial formation density and the actual formation density is greater than a preset error threshold.

[0090] In some specific embodiments, the formation fracture height position correction module 13 may specifically include:

[0091] A constraint condition building module, used to build a constraint condition based on the initial formation density and the initial photoelectric absorption cross-section index value;

[0092] The cost function building module is used to eliminate the difference between the actual gap and the fracturing fluid information by using a nonlinear inversion method, and to build a cost function based on the constraint conditions.

[0093] In some specific embodiments, the near-wellbore hydraulic fracturing fracture evaluation module 14 may specifically include:

[0094] An optimization module, used for optimizing the cost function by using the Macquart method to obtain the optimized cost function;

[0095] The iterative inversion module is used to iteratively invert the optimized cost function to obtain the target formation density and the target photoelectric absorption cross-section index value.

[0096] Figure 7 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. The electronic device 20 may specifically include: at least one processor 21, at least one memory 22, a power supply 23, a communication interface 24, an input / output interface 25, and a communication bus 26. The memory 22 is used to store a computer program, which is loaded and executed by the processor 21 to implement the relevant steps in the near-wellbore hydraulic fracturing fracture evaluation method performed by the electronic device disclosed in any of the aforementioned embodiments.

[0097] In this embodiment, the power supply 23 is used to provide working voltage for each hardware device on the electronic device 20; the communication interface 24 can create a data transmission channel between the electronic device 20 and the external device, and the communication protocol it follows is any communication protocol that can be applied to the technical solution of the present application, and is not specifically limited here; the input and output interface 25 is used to obtain external input data or output data to the outside world, and its specific interface type can be selected according to specific application needs and is not specifically limited here.

[0098] In addition, the memory 22, as a carrier for storing resources, can be a read-only memory, a random access memory, a disk or an optical disk, etc. The resources stored thereon include an operating system 221, a computer program 222 and data 223, etc. The storage method can be temporary storage or permanent storage.

[0099] Among them, the operating system 221 is used to manage and control the hardware devices and computer programs 222 on the electronic device 20 to realize the operation and processing of the data 223 in the memory 22 by the processor 21, which can be Windows, Unix, Linux, etc. In addition to including a computer program that can be used to complete the near-wellbore hydraulic fracturing fracture evaluation method performed by the electronic device 20 disclosed in any of the aforementioned embodiments, the computer program 222 can further include a computer program that can be used to complete other specific tasks. In addition to including data transmitted from an external device received by the near-wellbore hydraulic fracturing fracture evaluation device, the data 223 can also include data collected by its own input and output interface 25, etc.

[0100] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0101] Furthermore, an embodiment of the present application also discloses a computer-readable storage medium, in which a computer program is stored. When the computer program is loaded and executed by a processor, the steps of the near-wellbore hydraulic fracturing fracture evaluation method disclosed in any of the aforementioned embodiments are implemented.

[0102] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0103] The above is a detailed introduction to a near-wellbore hydraulic fracturing fracture evaluation method, device, equipment and storage medium provided by the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for general technicians in this field, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A method for evaluating near-wellbore hydraulic fracturing fractures, characterized in that: include: Detecting formation fractures, and if proppant is detected in the formation fractures, performing energy spectrum measurement on the formation fractures to obtain scattered gamma energy spectra, and performing data processing on the scattered gamma energy spectra to obtain processed data; Determine an initial formation density and an initial photoelectric absorption cross-section index value based on the processed data, and calculate an initial formation fracture height and an initial formation fracture position according to the initial formation density and the initial photoelectric absorption cross-section index value; A cost function is constructed using the initial formation density and the initial photoelectric absorption cross-section index value, and the cost function is optimized and iterated to obtain a target formation density and a target photoelectric absorption cross-section index value, and the initial formation fracture height and the initial formation fracture position are corrected according to the target formation density and the target photoelectric absorption cross-section index value to obtain a target formation fracture height and a target formation fracture position; A correlation between the target formation density and the target photoelectric absorption cross-section index value and the crack width is established, and the target formation crack width is calculated using the correlation relationship. Based on the target formation crack height, the target formation crack position and the target formation crack width, an evaluation of near-wellbore hydraulic fracturing cracks is achieved.

2. The near-wellbore hydraulic fracturing fracture evaluation method according to claim 1, characterized in that: The performing energy spectrum measurement on the formation fracture to obtain each scattered gamma energy spectrum includes: The stratum fractures are measured for scattered gamma energy spectra using a preset X-ray lithology density instrument to obtain scattered gamma energy spectra; wherein the X-ray lithology density instrument includes an X-ray tube and a gamma detector.

3. The near-wellbore hydraulic fracturing fracture evaluation method according to claim 1, characterized in that: The step of performing data processing on each of the scattered gamma energy spectra to obtain processed data includes: Each of the scattered gamma energy spectra is subjected to filtering and denoising processing to obtain the scattered gamma energy spectra after filtering and denoising processing, and then the scattered gamma energy spectra after filtering and denoising processing are divided into energy windows to obtain processed data.

4. The near-wellbore hydraulic fracturing fracture evaluation method according to claim 3, characterized in that: The filtering and denoising process is performed on each of the scattered gamma energy spectra to obtain the scattered gamma energy spectra after the filtering and denoising process, and then the scattered gamma energy spectra after the filtering and denoising process are divided into energy windows to obtain processed data, including: Using a Kalman filter algorithm to perform filtering and noise reduction processing on each of the scattered gamma energy spectra to obtain the scattered gamma energy spectra after filtering and noise reduction processing; The scattered gamma energy spectrum after filtering and noise reduction is divided into energy windows according to a preset number of energy window divisions to obtain processed data.

5. The near-wellbore hydraulic fracturing fracture evaluation method according to claim 1, characterized in that: The step of calculating the initial formation fracture height and the initial formation fracture position according to the initial formation density and the initial photoelectric absorption cross-section index value comprises: Acquire actual formation density, and determine whether a density error value between the initial formation density and the actual formation density is greater than a preset error threshold; If the density error value between the initial formation density and the actual formation density is greater than a preset error threshold, the initial formation fracture height and the initial formation fracture position are calculated based on the initial formation density and the initial photoelectric absorption cross-section index value.

6. The near-wellbore hydraulic fracturing fracture evaluation method according to claim 1, characterized in that: The constructing a cost function using the initial formation density and the initial photoelectric absorption cross-section index value comprises: Constructing constraint conditions based on the initial formation density and the initial photoelectric absorption cross-section index value; A nonlinear inversion method is used to eliminate the difference between the actual gap and the fracturing fluid information, and a cost function is constructed based on the constraint conditions.

7. The near-wellbore hydraulic fracturing fracture evaluation method according to any one of claims 1 to 6, characterized in that: The optimizing and iterating the cost function to obtain the target formation density and the target photoelectric absorption cross-section index value includes: The cost function is optimized by using the McQuarter method to obtain the optimized cost function; The optimized cost function is iteratively inverted to obtain the target formation density and the target photoelectric absorption cross-section index value.

8. A near-wellbore hydraulic fracturing fracture evaluation device, characterized in that: include: An energy spectrum measurement and processing module is used to detect formation fractures. If proppant is detected in the formation fractures, energy spectrum measurement is performed on the formation fractures to obtain scattered gamma energy spectra, and data processing is performed on the scattered gamma energy spectra to obtain processed data. A formation fracture height position determination module, used to determine an initial formation density and an initial photoelectric absorption cross-sectional index value based on the processed data, and calculate an initial formation fracture height and an initial formation fracture position according to the initial formation density and the initial photoelectric absorption cross-sectional index value; A formation fracture height position correction module, used to construct a cost function using the initial formation density and the initial photoelectric absorption cross-section index value, optimize and iterate the cost function to obtain a target formation density and a target photoelectric absorption cross-section index value, and correct the initial formation fracture height and the initial formation fracture position according to the target formation density and the target photoelectric absorption cross-section index value to obtain a target formation fracture height and a target formation fracture position; The near-wellbore hydraulic fracturing crack evaluation module is used to establish a correlation between the target formation density and the target photoelectric absorption cross-section index value and the crack width, calculate the target formation crack width using the correlation, and evaluate the near-wellbore hydraulic fracturing crack based on the target formation crack height, the target formation crack position and the target formation crack width.

9. An electronic device, characterized in that: include: Memory, used to store computer programs; A processor is used to execute the computer program to implement the near-wellbore hydraulic fracturing fracture evaluation method as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: Used to store a computer program; wherein, when the computer program is executed by a processor, the near-wellbore hydraulic fracturing fracture evaluation method according to any one of claims 1 to 7 is implemented.

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