A near wellbore hydraulic fracture evaluation method, device, equipment and medium

Abstract

The application discloses a near wellbore hydraulic fracturing fracture evaluation method, device, equipment and medium, relates to the oil and gas exploration and development technical field, and includes processing of each scattered gamma energy spectrum data; determining initial formation density and initial photoelectric absorption cross section index value based on the processed data, calculating initial formation fracture height and initial formation fracture position; constructing a cost function, optimizing and iterating the cost function, obtaining target formation density and target photoelectric absorption cross section index value, correcting the initial formation fracture height and the initial formation fracture position, obtaining target formation fracture height and target formation fracture position; establishing a correlation relationship, calculating target formation fracture width, realizing near wellbore hydraulic fracturing fracture evaluation, and accurately determining formation fracture position and formation fracture parameters, increasing the sensitivity of fracture response, improving the efficiency and accuracy of near wellbore hydraulic fracturing fracture evaluation, and reducing the complexity of measurement before and after fracturing.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil and gas exploration and development, and particularly relates to a near wellbore hydraulic fracturing fracture evaluation method, device, equipment and medium. BACKGROUND

[0002] At present, the near wellbore fracturing fracture diagnosis technology mainly includes acoustic-electric imaging logging, well temperature logging, radioactive tracer logging, and non-radioactive tracer logging based on pulse neutron technology. Among them, the acoustic-electric imaging logging and the well temperature logging can only determine the position of the fracture, and the precision is not high; the radioactive tracer logging uses radioactive tracer elements as tracers to evaluate the fracture parameters, and the radioactive element tracer has certain harm to the environment and human body, and has been gradually abandoned; when the non-radioactive tracer logging based on the pulse neutron technology is used to evaluate the fracture, the high-heat neutron capture cross-section element will cause the neutron self-shielding effect, which greatly reduces the response sensitivity of the fracture, and for larger fractures, it can only be determined whether they exist or not, and the quantitative calculation of the fracture parameters cannot be performed, and the method needs to be measured before and after fracturing.

[0003] From the above, how to accurately determine the formation fracture position and the formation fracture parameters, increase the sensitivity of the fracture response, improve the efficiency and accuracy of the near wellbore hydraulic fracturing fracture evaluation, and reduce the complexity of the measurement before and after fracturing is a problem to be solved in the field. SUMMARY

[0004] Therefore, the purpose of the present application is to provide a near wellbore hydraulic fracturing fracture evaluation method, device, equipment and medium, which can accurately determine the formation fracture position and the formation fracture parameters, increase the sensitivity of the fracture response, improve the efficiency and accuracy of the near wellbore hydraulic fracturing fracture evaluation, and reduce the complexity of the 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 the formation fracture, if the proppant exists in the formation fracture, performing energy spectrum measurement on the formation fracture to obtain each scattered gamma spectrum, and performing data processing on each scattered gamma spectrum to obtain processed data;

[0007] determining the initial formation density and the initial photoelectric absorption cross-section index value based on the processed data, 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;

[0008] A cost function is constructed by using the initial formation density and the initial photoelectric absorption cross-section index value, and the cost function is iteratively optimized 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, the target photoelectric absorption cross-section index value and a fracture width is established, the target formation fracture width is calculated by using the correlation, and the near-wellbore hydraulic fracturing fracture is evaluated based on the target formation fracture height, the target formation fracture position and the target formation fracture width.

[0010] Optionally, the energy spectrum measurement on the formation fracture is performed to obtain each scattered gamma energy spectrum, including:

[0011] The scattered gamma energy spectrum measurement on the formation fracture is performed by using a preset X-ray lithology density instrument to obtain each scattered gamma energy spectrum, wherein the X-ray lithology density instrument includes an X-ray tube and a gamma detector.

[0012] Optionally, the data processing on each scattered gamma energy spectrum is performed to obtain processed data, including:

[0013] Each scattered gamma energy spectrum is subjected to filtering and noise reduction processing to obtain the scattered gamma energy spectrum after filtering and noise reduction processing, and the scattered gamma energy spectrum after filtering and noise reduction processing is subjected to energy window division to obtain processed data.

[0014] Optionally, the filtering and noise reduction processing on each scattered gamma energy spectrum is performed to obtain the scattered gamma energy spectrum after filtering and noise reduction processing, and the scattered gamma energy spectrum after filtering and noise reduction processing is subjected to energy window division to obtain processed data, including:

[0015] Each scattered gamma energy spectrum is subjected to filtering and noise reduction processing by using a Kalman filtering algorithm to obtain the scattered gamma energy spectrum after filtering and noise reduction processing.

[0016] The scattered gamma energy spectrum after filtering and noise reduction processing is subjected to energy window division according to a preset number of energy window division to obtain processed data.

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

[0018] An actual formation density is obtained, and it is determined 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, an initial formation fracture height and an initial formation fracture position are calculated based on the initial formation density and the initial photoelectric absorption cross-section index value.

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

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

[0022] Differences in actual gaps and fracturing fluid information are eliminated using a nonlinear inversion method, and a cost function is constructed based on the constraint condition.

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

[0024] The cost function is optimized using the Marquardt method to obtain an optimized cost function;

[0025] The optimized cost function is iteratively inverted to obtain a target formation density and a 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] A spectrum measurement processing module is configured to detect a formation fracture, and if proppants are detected in the formation fracture, perform spectrum measurement on the formation fracture to obtain each scattered gamma spectrum, and perform data processing on each scattered gamma spectrum to obtain processed data.

[0028] A formation fracture height and position determination module is configured to 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.

[0029] A formation fracture height and position correction module is configured to construct a cost function using the initial formation density and the initial photoelectric absorption cross-section index value, optimize iteration of 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 fracture evaluation module is used to 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 by using the correlation, and realize the near wellbore hydraulic fracturing fracture evaluation based on the target formation fracture height, the target formation fracture position and the target formation fracture width.

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

[0032] A memory is configured to store a computer program.

[0033] A processor is configured to execute the computer program to realize the near wellbore hydraulic fracturing fracture evaluation method.

[0034] In a fourth aspect, the present application discloses a computer storage medium configured to store a computer program; wherein the computer program is executed by a processor to realize the steps of the near wellbore hydraulic fracturing fracture evaluation method disclosed above.

[0035] It can be seen that the application provides a near wellbore hydraulic fracturing fracture evaluation method, which comprises detecting a formation fracture, if the proppant exists in the formation fracture, 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, determining an initial formation density and an initial photoelectric absorption cross-section index value based on the processed data, 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, constructing a cost function by using the initial formation density and the initial photoelectric absorption cross-section index value, performing optimization iteration on the cost function to obtain a target formation density and a target photoelectric absorption cross-section index value, correcting 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, establishing a correlation between the target formation density and the target photoelectric absorption cross-section index value and a fracture width, calculating a target formation fracture width by using the correlation, and realizing near wellbore hydraulic fracturing fracture evaluation based on the target formation fracture height, the target formation fracture position and the target formation fracture width. The application realizes energy spectrum measurement on the formation fracture by using photoelectric effect and Compton effect of the proppant, thereby obtaining the scattered gamma energy spectrum, and realizes correction of the initial formation fracture height and the formation fracture position by optimization iteration of the cost function, thereby obtaining the target formation fracture height and the target formation fracture position, so that the formation fracture position and the formation fracture parameter can be accurately determined, the sensitivity of the fracture response is increased, the correlation between the target formation density and the target photoelectric absorption cross-section index value and the fracture width is established, thereby calculating the target formation fracture width, so as to realize near wellbore hydraulic fracturing fracture evaluation, and the efficiency and accuracy of the near wellbore hydraulic fracturing fracture evaluation can be improved, and the complexity of measurement before and after fracturing is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only constitute the embodiments of the application, and for those skilled in the art, other drawings can be obtained without creative labor based on the provided drawings.

[0037] Figure 1 A near wellbore hydraulic fracturing fracture evaluation method flow chart is disclosed in the application.

[0038] Figure 2 An X-ray density fracture measurement schematic diagram is disclosed in the application.

[0039] Figure 3 A near wellbore hydraulic fracturing fracture evaluation method flow chart disclosed by the application;

[0040] Figure 4 A scattered gamma ray spectrum response result example chart disclosed by the application;

[0041] Figure 5 A theoretical density value and actual density calculation response comparison example chart disclosed by the application;

[0042] Figure 6 A near wellbore hydraulic fracturing fracture evaluation device structure schematic diagram disclosed by the application;

[0043] Figure 7 An electronic device structure chart provided by the application. DETAILED DESCRIPTION

[0044] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative efforts fall within the protection scope of the application.

[0045] 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 pulse neutron technology. Among them, the acoustic-electric imaging logging and the well temperature logging can only determine the fracture position, and the precision is not high; the radioactive tracer logging uses radioactive tracer elements as tracers to evaluate the fracture parameters, and the radioactive element tracers have certain harm to the environment and human body, and have been gradually abandoned; when the non-radioactive tracer logging based on the pulse neutron technology is used to evaluate the fracture, the high-heat neutron capture cross-section elements will cause the neutron self-shielding effect, which greatly reduces the response sensitivity of the fracture, and for larger fractures, it can only be determined whether the fractures exist or not, and the quantitative calculation of the fracture parameters cannot be performed, and the method needs to be measured once before and after fracturing. As can be seen from the above, how to accurately determine the formation fracture position and the formation fracture parameters, increase the sensitivity of the fracture response, improve the efficiency and accuracy of the near wellbore hydraulic fracturing fracture evaluation, and reduce the complexity of the measurement before and after fracturing is a problem to be solved in the field.

[0046] Referring to Figure 1 The embodiments of the application disclose a near wellbore hydraulic fracturing fracture evaluation method, which can specifically include:

[0047] Step S11: detecting the formation fracture, if the proppant exists in the formation fracture, performing energy spectrum measurement on the formation fracture to obtain each scattered gamma spectrum, and performing data processing on each scattered gamma spectrum to obtain processed data.

[0048] In the embodiment, the formation fracture is detected, if the proppant exists in the formation fracture, scattered gamma spectrum measurement is performed on the formation fracture by using a preset X-ray lithology density instrument to obtain each scattered gamma spectrum; the X-ray lithology density instrument includes an X-ray tube and a gamma detector, and then data processing is performed on each scattered gamma spectrum to obtain processed data.

[0049] The data processing process is that: each scattered gamma spectrum is subjected to filtering and noise reduction processing to obtain the scattered gamma spectrum after filtering and noise reduction processing, and then the scattered gamma spectrum after filtering and noise reduction processing is subjected to energy window division to obtain processed data. Specifically, each scattered gamma spectrum is subjected to filtering and noise reduction processing by using a Kalman filtering algorithm to obtain the scattered gamma spectrum after filtering and noise reduction processing; the scattered gamma spectrum after filtering and noise reduction processing is subjected to energy window division 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 the embodiment, by adding an element with a Pe value (Photoelectric absorption Eoss-section index, high photoelectric absorption cross-section index value) as a tracer in the fracturing proppant, the X-ray lithology density device is used to measure the formation after fracturing, the high and low energy window counting is used to analyze the changes of the formation lithology and density to identify the position of the proppant, and then the parameters such as the fracture position, height and width are determined. The specific steps are as follows: (1) in the process of hydraulic fracturing, special proppants containing Ba (Barium, barium element), Fe (Ferrum, iron element) and other high photoelectric absorption cross-section elements are mixed in the fracturing fluid and pumped into the formation; (2) the X-ray lithology density instrument is used to measure the scattered gamma spectrum information at different depths; (3) the scattered gamma spectrum measured by the X-ray lithology density instrument is subjected to data processing, and the processed data is obtained. The proppant is mainly made of quartz sand or artificial ceramic particles, and mixed with BaSO4, FeS2 and other substances with high photoelectric absorption cross-section index to be sintered; the X-ray lithology density instrument includes an X-ray source and at least two X-ray detectors. The fracturing measurement schematic diagram of the X-ray lithology density instrument is as shown in Figure 2As shown, the X-ray lithology density instrument mainly comprises an X-ray tube, at least two gamma detectors, and the detector and the X-ray source are both designed with openings to improve the detection efficiency of the gamma rays. During the measurement process, the X-ray lithology density instrument is closely attached to the well wall for measurement, Figure 2 1 is an X-ray source, 2 is an X-ray source opening, 3 is a near detector opening, 4 is a fracture and the fracture is filled with special proppant, 5 is a far detector opening, 6 is a far gamma detector, 7 is a near gamma detector, 8 is a parallel eye, and 9 is a 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: constructing a cost function by using the initial formation density and the initial photoelectric absorption cross-section index value, optimizing and iterating the cost function to obtain a target formation density and a target photoelectric absorption cross-section index value, and correcting 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.

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

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

[0055] Step S14: establishing a correlation between the target formation density and the target photoelectric absorption cross-section index value and the fracture width, calculating a target formation fracture width by using the correlation, and realizing the near wellbore hydraulic fracturing fracture evaluation based on the target formation fracture height, the target formation fracture position, and the target formation fracture width.

[0056] In the embodiment, the formation fracture is detected, if the proppant exists in the formation fracture, the energy spectrum measurement is performed on the formation fracture to obtain each scattered gamma spectrum, the data processing is performed on each scattered gamma spectrum to obtain processed data, the initial formation density and the initial photoelectric absorption cross-section index value are determined based on the processed data, the initial formation fracture height and the initial formation fracture position are calculated according to the initial formation density and the initial photoelectric absorption cross-section index value, the cost function is constructed by using the initial formation density and the initial photoelectric absorption cross-section index value, the optimization iteration is performed on the cost function to obtain the target formation density and the target photoelectric absorption cross-section index value, 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, the correlation between the target formation density and the target photoelectric absorption cross-section index value and the fracture width is established, the target formation fracture width is calculated by using the correlation, and the near wellbore hydraulic fracturing fracture evaluation is realized based on the target formation fracture height, the target formation fracture position and the target formation fracture width. The photoelectric effect and the Compton effect of the proppant are utilized to realize the energy spectrum measurement on the formation fracture, so that the scattered gamma spectrum is obtained, the initial bottom fracture height and the formation fracture position are obtained by the data processing on the scattered gamma spectrum, the initial bottom fracture height and the formation fracture position are corrected by the optimization iteration of the cost function, the target formation fracture height and the target formation fracture position are obtained, so that the formation fracture position and the formation fracture parameter are accurately determined, the sensitivity of the fracture response is increased, the correlation between the target formation density and the target photoelectric absorption cross-section index value and the fracture width is established, so that the target formation fracture width is calculated, and the near wellbore hydraulic fracturing fracture evaluation is realized, the efficiency and the accuracy of the near wellbore hydraulic fracturing fracture evaluation are improved, and the complexity of the measurement before and after fracturing is reduced.

[0057] Referring to Figure 3 The embodiment of the present application discloses a near wellbore hydraulic fracturing fracture evaluation method, which can specifically include:

[0058] In step S21, the formation fracture is detected, if the proppant exists in the formation fracture, the energy spectrum measurement is performed on the formation fracture to obtain each scattered gamma spectrum, and the data processing is performed on each scattered gamma spectrum to obtain processed data.

[0059] Step S22: determining an initial formation density and an initial photoelectric absorption cross-section index value based on the processed data, obtaining an actual formation density, determining whether a density error value between the initial formation density and the actual formation density is greater than a preset error threshold, and if the density error value between the initial formation density and the actual formation density is greater than the preset error threshold, calculating an initial formation fracture height and an 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 the scattered gamma spectrum is shown in FIG. 2. Figure 4 Figure 4 The scattered gamma spectrum response results measured by the detector when the fracture width is 0 cm and 0.4 cm, respectively, are shown in FIG. 2. The scattered gamma spectrum measured by different detectors of the X-ray lithology density instrument is processed, wherein the Kalman filtering algorithm is used for scattered gamma spectrum filtering and noise reduction, and the scattered gamma spectrum is divided into five energy windows, namely, W1, W2, W3, W4 and W5, in the range of 0-0.25 MeV, and the energy interval of each energy window is 0.05 MeV, wherein the high-energy range is W3+W4, and the low-energy range is W1. Figure 4

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

[0062] wherein Counts_W3 and Counts_W4 are the gamma counts in the energy windows W3 and W4. The photoelectric absorption cross-section index Pe still uses the conventional high-to-low energy window count ratio, and the calculation formula is as follows:

[0063]

[0064] wherein a1 and b1 are constant coefficients, and Counts_W1 is the gamma count in the energy window W1. The position and height of the fracture are determined by the abnormally high value changes of the detector density and the photoelectric cross-section absorption index Pe calculated by the energy window method.

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

[0066] ​​Step S24: performing optimization iteration on the cost function to obtain a target formation density and a target photoelectric absorption cross-section index value, correcting 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.

[0067] Step S25: establishing a correlation between the target formation density and the target photoelectric absorption cross-section index value and a fracture width, calculating a target formation fracture width by using the correlation, and realizing the near wellbore hydraulic fracturing fracture evaluation based on the target formation fracture height, the target formation fracture position and the target formation fracture width.

[0068] In the embodiment, the information difference influence of the actual gap and the fracturing fluid information is eliminated by using the actual gap and the fracturing fluid information and adopting a nonlinear inversion method, so as to subsequently calculate accurate target formation density and target photoelectric absorption cross-section index value, and accurately determine related parameters such as proppant, fracture position and fracture height. In the embodiment, the information difference influence of the actual gap and the fracturing fluid information is eliminated by using the actual gap and the fracturing fluid information and adopting a nonlinear inversion method. In the inversion process, the relationship between the count in the detector energy window and the formation density, the photoelectric cross-section absorption index and the like can be described by the following formula:

[0069]

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

[0071]

[0072] wherein ||·||2 2 represents the square of the L2 norm, ||W A ·e(p)| 2 is the L2 norm of the difference between the detector density response vector S(p) calculated based on and the measured gamma density measurement d s , i.e. e(p) = S(p)-d s , p is a parameter vector to be inverted, including the formation density, Pe and the gap. λ||W B• (p + p0) || is a regularization term, mainly to prevent overfitting, suppress the error caused by radioactive statistical fluctuations, p0 is the initial formation nuclear characteristic parameter reference vector, λ is the regularization parameter, W A and W B are weights. The cost function formula is processed and iteratively calculated by using the L-M method. The mathematical relationship between the fracture width or density is established by using the solved actual density of the formation and the Pe result, so that the quantitative calculation of the fracture width or density can be realized. Figure 5 The response of the theoretical density value to the actual density when the fracture width increases from 0 cm to 2 cm. As can be seen from the figure, when the fracture is filled with special proppants containing BaSO4, etc., the density value calculated by the detector is much larger than the actual density, and the density anomaly appears, which can realize the judgment of the fracture, and the quantitative calculation of the fracture parameters is realized through the established correlation relationship.

[0073] In the embodiment, the formation fracture is detected, if the proppant exists in the formation fracture, the energy spectrum measurement is performed on the formation fracture to obtain each scattered gamma spectrum, the data processing is performed on each scattered gamma spectrum to obtain processed data, the initial formation density and the initial photoelectric absorption cross-section index value are determined based on the processed data, the initial formation fracture height and the initial formation fracture position are calculated according to the initial formation density and the initial photoelectric absorption cross-section index value, the cost function is constructed by using the initial formation density and the initial photoelectric absorption cross-section index value, the optimization iteration is performed on the cost function to obtain the target formation density and the target photoelectric absorption cross-section index value, 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, the correlation between the target formation density and the target photoelectric absorption cross-section index value and the fracture width is established, the target formation fracture width is calculated by using the correlation, and the near wellbore hydraulic fracturing fracture evaluation is realized based on the target formation fracture height, the target formation fracture position and the target formation fracture width. The photoelectric effect and the Compton effect of the proppant are utilized to realize the energy spectrum measurement on the formation fracture, so that the scattered gamma spectrum is obtained, the initial bottom fracture height and the formation fracture position are obtained by the data processing on the scattered gamma spectrum, the initial bottom fracture height and the formation fracture position are corrected by the optimization iteration of the cost function, the target formation fracture height and the target formation fracture position are obtained, so that the formation fracture position and the formation fracture parameter are accurately determined, the sensitivity of the fracture response is increased, the correlation between the target formation density and the target photoelectric absorption cross-section index value and the fracture width is established, so that the target formation fracture width is calculated, and the near wellbore hydraulic fracturing fracture evaluation is realized, the efficiency and the accuracy of the near wellbore hydraulic fracturing fracture evaluation are improved, and the complexity of the measurement before and after fracturing is reduced.

[0074] Referring to Figure 6 As shown in the figure, the embodiment of the present application discloses a near wellbore hydraulic fracturing fracture evaluation device, which can specifically include:

[0075] The energy spectrum measurement processing module 11 is configured to detect the formation fracture, if the proppant exists in the formation fracture, perform the energy spectrum measurement on the formation fracture to obtain each scattered gamma spectrum, and perform the data processing on each scattered gamma spectrum to obtain processed data.

[0076] The formation fracture height position determination module 12 is configured to determine the initial formation density and the initial photoelectric absorption cross-section index value based on the processed data, and calculate 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.

[0077] a formation fracture height and location correction module 13 configured to construct a cost function using the initial formation density and the initial photoelectric absorption cross-section exponent value, to perform an optimization iteration on the cost function to obtain a target formation density and a target photoelectric absorption cross-section exponent value, and to correct the initial formation fracture height and the initial formation fracture location according to the target formation density and the target photoelectric absorption cross-section exponent value to obtain a target formation fracture height and a target formation fracture location;

[0078] a near-wellbore hydraulic fracture evaluation module 14 configured to establish a correlation between the target formation density and the target photoelectric absorption cross-section exponent value and a fracture width, to calculate a target formation fracture width using the correlation, and to realize near-wellbore hydraulic fracture evaluation based on the target formation fracture height, the target formation fracture location, and the target formation fracture width.

[0079] In the embodiment, the formation fracture is detected, if the proppant exists in the formation fracture, the energy spectrum measurement is performed on the formation fracture to obtain each scattered gamma energy spectrum, the data processing is performed on each scattered gamma energy spectrum to obtain processed data, the initial formation density and the initial photoelectric absorption cross-section index value are determined based on the processed data, the initial formation fracture height and the initial formation fracture position are calculated according to the initial formation density and the initial photoelectric absorption cross-section index value, the cost function is constructed by using the initial formation density and the initial photoelectric absorption cross-section index value, the optimization iteration is performed on the cost function to obtain the target formation density and the target photoelectric absorption cross-section index value, 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, the correlation between the target formation density and the target photoelectric absorption cross-section index value and the fracture width is established, the target formation fracture width is calculated by using the correlation, and the near wellbore hydraulic fracturing fracture evaluation is realized based on the target formation fracture height, the target formation fracture position and the target formation fracture width. The photoelectric effect and the Compton effect of the proppant are utilized to realize the energy spectrum measurement on the formation fracture, so that the scattered gamma energy spectrum is obtained, the initial bottom fracture height and the formation fracture position are obtained by the data processing on the scattered gamma energy spectrum, the initial bottom fracture height and the formation fracture position are corrected by the optimization iteration of the cost function, the target formation fracture height and the target formation fracture position are obtained, so that the formation fracture position and the formation fracture parameter are accurately determined, the sensitivity of the fracture response is increased, the correlation between the target formation density and the target photoelectric absorption cross-section index value and the fracture width is established, so that the target formation fracture width is calculated, and the near wellbore hydraulic fracturing fracture evaluation is realized, the efficiency and the accuracy of the near wellbore hydraulic fracturing fracture evaluation are improved, and the complexity of the measurement before and after fracturing is reduced.

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

[0081] The scattered gamma energy spectrum measurement module is used for performing the scattered gamma energy spectrum measurement on the formation fracture by using a preset X-ray lithology density instrument to obtain each scattered gamma energy 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 can specifically include:

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

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

[0085] The filtering and noise reduction processing module is configured to perform filtering and noise reduction processing on each of the scattered gamma energy spectra by using a Kalman filtering algorithm to obtain the scattered gamma energy spectra after filtering and noise reduction processing.

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

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

[0088] The judgment module is configured to obtain an 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 initial formation fracture height and position determination module is configured to calculate an initial formation fracture height and an initial formation fracture position based on the initial formation density and the initial photoelectric absorption cross-section index value if the density error value between the initial formation density and the actual formation density is greater than the preset error threshold.

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

[0091] The constraint condition construction module is configured to construct a constraint condition based on the initial formation density and the initial photoelectric absorption cross-section index value.

[0092] The cost function construction module is configured to perform difference elimination on actual gaps and fracturing fluid information by using a nonlinear inversion method, and construct a cost function based on the constraint condition.

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

[0094] The optimization module is configured to optimize the cost function by using a Marquardt method to obtain the optimized cost function.

[0095] The iterative inversion module is configured to perform iterative inversion on the optimized cost function to obtain a target formation density and a target photoelectric absorption cross-section index value.

[0096] Figure 7 A structural schematic diagram of an electronic device is provided in the embodiments of the present application. The electronic device 20 can 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 configured to store a computer program, and the processor 21 is configured to load and execute the computer program to implement the related steps in the near wellbore hydraulic fracturing fracture evaluation method performed by the electronic device disclosed in any of the foregoing embodiments.

[0097] In the embodiments, the power supply 23 is configured to provide working voltage for each hardware device on the electronic device 20; the communication interface 24 is capable of creating a data transmission channel between the electronic device 20 and external devices, and the communication protocol followed by the communication interface 24 can be any communication protocol applicable to the technical solutions of the present application, which is not specifically limited herein; the input / output interface 25 is configured to obtain external input data or output data to the outside, and the specific interface type can be selected according to specific application needs, which is not specifically limited herein.

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

[0099] The operating system 221 is configured to manage and control each hardware device on the electronic device 20 and the computer program 222, so as to implement the operation and processing of the processor 21 on the data 223 in the memory 22, and the operating system 221 can be Windows, Unix, Linux, etc. The computer program 222 can further include computer programs capable of completing other specific work in addition to the computer programs capable of completing the near wellbore hydraulic fracturing fracture evaluation method performed by the electronic device 20 disclosed in any of the foregoing embodiments. The data 223 can include data transmitted from external devices received by the near wellbore hydraulic fracturing fracture evaluation device, and can also include data collected by the input / output interface 25 itself, etc.

[0100] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, software modules executed by a processor, or a combination thereof. The software modules can 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 technical field.

[0101] Further, the application further discloses a computer readable storage medium, wherein the storage medium stores a computer program, and the computer program is loaded and executed by a processor to implement the steps of the near wellbore hydraulic fracturing fracture evaluation method disclosed in any of the preceding embodiments.

[0102] Finally, it should be noted that in this document, the terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between the entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitations, the element defined by the statement "including a" does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0103] The above describes in detail the near wellbore hydraulic fracturing fracture evaluation method, device, equipment and storage medium provided by the application. The principles and implementation manners of the application are described by using specific examples in this document. The above description of the embodiments is only used to help understand the method of the application and its core idea. Meanwhile, for those skilled in the art, according to the idea of the application, the specific implementation manners and application ranges can be changed. In summary, the content of the specification should not be understood as a limitation of the application.

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; 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; constructing a cost function using the initial formation density and the initial photoelectric absorption cross-section index value, iteratively optimizing the cost function to obtain a target formation density and a target photoelectric absorption cross-section index value, and correcting 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; A correlation between the target formation density, the target photoelectric absorption cross-section index value and the crack width is established, the target formation crack width is calculated using the correlation, and the near-wellbore hydraulic fracturing crack is evaluated based on the target formation crack height, the target formation crack position and the target formation crack width.

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 by scattered gamma energy spectrum using a preset X-ray lithologic density instrument to obtain scattered gamma energy spectra; wherein the X-ray lithologic 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 performing data processing on each of the scattered gamma energy spectra to obtain processed data includes: 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, and then perform energy window division on the scattered gamma energy spectra after filtering and noise reduction processing 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 filtering and denoising, and then energy window division is performed on the scattered gamma energy spectra after filtering and denoising to obtain processed data, including: Performing filtering and noise reduction processing on each of the scattered gamma energy spectra using a Kalman filter algorithm 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 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: Acquire actual formation density, and determine whether a density error between the initial formation density and the actual formation density is greater than a preset error threshold; If the density error 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 of a cost function using the initial formation density and the initial photoelectric absorption cross-section index value includes: Establishing a constraint condition 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 iterative optimization of the cost function to obtain a target formation density and a target photoelectric absorption cross-section index value includes: Optimizing the cost function using the Macquart method to obtain an optimized cost function; The optimized cost function is iteratively inverted to obtain target formation density and 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, configured to detect formation fractures, and if proppant is detected in the formation fractures, perform energy spectrum measurement on the formation fractures to obtain scattered gamma energy spectra, and perform data processing on the scattered gamma energy spectra to obtain processed data; a formation fracture height position determination module, configured to 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 formation fracture height position correction module, configured to construct a cost function using the initial formation density and the initial photoelectric absorption cross-section index value, iteratively optimize 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 fracture evaluation module is used to 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.

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 according to 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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