A shale oil reservoir fracture uniform expansion real-time regulation method and system

Abstract

The application discloses a shale oil reservoir fracture uniform expansion real-time regulation method and system, belongs to the technical field of oil and natural gas yield increase, and is based on shale oil reservoir parameter determination target well fracturing section and corresponding cluster, combines fracture liquid absorption profile information and Lorentz curve principle to calculate fracture expansion difference coefficient; according to the fracture expansion difference coefficient, the fracture expansion state is evaluated, the fracturing reconstruction scheme is dynamically adjusted according to the evaluation result, and the reconstruction effect is evaluated in real time; the method solves the problems of the existing technology, such as serious single fracture breakthrough, low fracturing fluid fracture efficiency, small fracturing fracture network swept volume and the like, and provides strong support for improving fracture unstable expansion and improving single well productivity.

Description

Technical Field

[0001] This invention relates to the field of oil and gas production enhancement technology, specifically to a method and system for real-time control of uniform fracture propagation in shale oil reservoirs. Background Technology

[0002] The low porosity and low permeability of shale oil reservoirs pose significant challenges to their effective development. Hydraulic fracturing, as an efficient reservoir stimulation method, has become the primary technology for successful shale oil development. However, due to the strong heterogeneity of shale oil reservoirs, the presence of natural fractures, and stress disturbances, the extension length of hydraulic fractures formed by multi-cluster fracturing in horizontal wells varies significantly across different layers and directions. Therefore, to address key issues such as severe single-fracture advance, low fracturing fluid fracturing efficiency, and small fracture network volume, developing a real-time control method to guide the uniform propagation of fractures in shale oil reservoirs is crucial for improving unstable fracture propagation and increasing single-well productivity.

[0003] Application No. 202110994782.5 discloses an optimization design method for perforation parameters in shale gas horizontal wells using close-cut fracturing. This method establishes a fully fluid-structure interaction model for the synchronous propagation of multiple fractures in close-cut fracturing of horizontal wells, predicting the fracturing fluid injection rate and hydraulic fracture propagation morphology of each perforation cluster. Then, it calculates the uniformity index of hydraulic fracture development in each cluster under different perforation parameter schemes, thereby guiding the uniform development of multiple hydraulic fracture clusters in close-cut fracturing of horizontal wells. However, this method of balancing the propagation rate of each fracture through flow-limited perforations is rather general and cannot accurately control underdeveloped fractures generated during fracturing in real time.

[0004] Application No. 202110066658.2 discloses a fracturing method and its application for uniform propagation of multiple fracture clusters. This method utilizes the unique rheological properties of shear-thickened slickwater to adaptively adjust the amount of fracturing fluid entering each fracture cluster. When the difference in fracturing fluid viscosity with shear rate is sufficiently large, the volume of fracturing fluid entering each cluster can be ensured to be roughly equal or similar, thereby promoting uniform fracture initiation and propagation. However, controlling the fluid inflow to each cluster using the rheological properties of the fracturing fluid has uncertainties, and for already established unfavorable channels, fracture control cannot be achieved by optimizing the fracturing fluid system.

[0005] Application No. 201910487076.4 describes an optimized design method for promoting uniform fracture propagation in horizontal wells using temporary plugging agents. This method comprehensively considers the migration and plugging patterns of temporary plugging agent particles within the fracture during dynamic fracture propagation, as well as the impact of stress interference between multiple fractures on the plugging effect. It calculates the optimal particle size, particle size distribution, and required volume for effective plugging in the target area, thereby improving the uniformity of fracture development in segmented, multi-cluster temporary plugging fracturing in horizontal wells. However, this method relies on generalized research results to guide field experiments without considering the complexities of fracture propagation during actual fracturing. The resulting fracture control is general, imprecise, and lacks timeliness, potentially even leading to some dominant fractures becoming underdeveloped fractures after control.

[0006] In summary, existing techniques for reducing the development gap between fractures mainly involve flow-limited perforations and parameter optimization. However, because these methods rely heavily on the precision of geological parameters, their effectiveness in controlling fracture propagation is uncertain. Furthermore, temporary plugging fracturing methods are also used domestically and internationally to control fracture propagation. This involves deploying a corresponding number of plugging balls or plugging agents based on the number of boreholes to be plugged or the fracture volume, promoting the further extension of underdeveloped fractures. However, temporary plugging fracturing methods do not consider the real-time fracture propagation, resulting in poor control effects. Summary of the Invention

[0007] To address the problems existing in the prior art, this invention provides a method and system for real-time control of uniform fracture propagation in shale oil reservoirs. This method solves the problems caused by existing technologies in shale oil reservoir modification, such as severe single fracture advance, low fracturing fluid fracturing efficiency, and small fracturing network volume. It provides strong support for improving unstable fracture propagation and increasing single-well productivity.

[0008] This invention is achieved through the following technical solution: In a first aspect, this application provides a method for real-time control of uniform fracture propagation in shale oil reservoirs, comprising the following processes: Based on shale oil reservoir parameters, the fracturing sections and corresponding clusters of the target well are determined. During the fracturing process, the fluid absorption profile information of each cluster of fractures in each fracturing section is obtained, and the fracture propagation difference coefficient is calculated by combining the Lorentz curve principle.

[0009] The fracture propagation status is evaluated based on the fracture propagation difference coefficient, and the fracturing stimulation scheme is dynamically adjusted based on the evaluation results, with the stimulation effect evaluated in real time.

[0010] Furthermore, the shale oil reservoir parameters include reservoir physical properties, geological parameters, rock mechanics parameters, and geostress parameters.

[0011] Furthermore, the calculation of the crack propagation difference coefficient includes: Lorentz curves are constructed based on the ratio of the total fluid absorption of each cluster of fractures within the target fracturing section to the cumulative fluid absorption of each cluster of fractures in all fracturing sections preceding the target fracturing section. The fracture propagation difference coefficient is determined based on the Lorentz curves to quantify the non-uniformity of fracture propagation.

[0012] Furthermore, the method for constructing the crack propagation difference coefficient includes: The fluid absorption of each cluster of fractures within the target fracturing section is sorted from smallest to largest. The ratio of the cumulative fluid absorption of each cluster of fractures to the total fluid absorption of the preceding clusters is calculated, as well as the ratio of the sequence number of each cluster of fractures to the total number of clusters. Based on these two ratios, an absolute uniformity line and a Lorentz curve for non-uniform fracture propagation are plotted. The fracture propagation difference coefficient is determined based on the coordinates of the absolute uniformity line and the Lorentz curve, which is used to quantify the degree of non-uniformity of fracture propagation.

[0013] Furthermore, the expression for the crack propagation difference coefficient is as follows:

[0014] in, k The sequence number is used to sort each cluster of fractures within the target fracturing section according to the amount of fluid absorbed. Q k The cumulative fluid absorption of the target fracturing section. P ( Q k The percentage represents the ratio of the total liquid uptake of each fracture cluster to the total liquid uptake of all preceding fracture clusters. P ( k The ratio of the sequence number of each crack cluster to the total number of clusters is denoted as . X 均匀 = P ( k ), Y 均匀 = P ( k The x and y coordinates of the crack propagation uniformity line are respectively: X 均匀 = P ( k ), Y 均匀 = P ( Q k (x) represents the horizontal and vertical coordinates of the Lorentz curve for non-uniform crack propagation.

[0015] Furthermore, the crack propagation difference coefficient is used to evaluate the crack propagation state, including: Multiple evaluation thresholds are set to characterize different crack propagation states. The crack propagation difference coefficient is compared with the evaluation thresholds to determine the crack propagation state.

[0016] Furthermore, the dynamically adjusted fracturing scheme includes: The first approach is that when the crack propagation difference coefficient is less than the first threshold, the crack propagation is relatively uniform. The second approach is to initiate new cracks by ball-drop fracturing when the crack propagation difference coefficient is greater than the first threshold and less than the second threshold. The third option is to initiate new cracks by ball-drop fracturing when the crack propagation difference coefficient is greater than or equal to the third threshold. The first threshold, the second threshold, and the third threshold increase sequentially; the number of pitches in the third scheme is less than the number of pitches in the second scheme.

[0017] Secondly, this application provides a real-time control system for uniform fracture propagation in shale oil reservoirs, characterized in that it includes: The first module is used to determine the fracturing section and corresponding cluster of the target well based on shale oil reservoir parameters, obtain the fluid absorption profile information of each cluster of fractures in each fracturing section during the fracturing process, and calculate the fracture propagation difference coefficient by combining the Lorentz curve principle. The second module is used to evaluate the fracture propagation state based on the fracture propagation difference coefficient, dynamically adjust the fracturing stimulation scheme based on the evaluation results, and evaluate the stimulation effect in real time.

[0018] Thirdly, this application provides an electronic device, characterized in that it includes: Memory, used to store computer programs; A processor is used to execute the computer program to implement the steps of the real-time control method for uniform fracture propagation in shale oil reservoirs.

[0019] Fourthly, this application provides a computer-readable storage medium, characterized in that the computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of the real-time control method for uniform expansion of fractures in shale oil reservoirs.

[0020] Compared with the prior art, the present invention has the following beneficial technical effects: This application provides a real-time control method for uniform fracture propagation in shale oil reservoirs. By monitoring fracture fluid absorption profile information in real time and calculating the fracture propagation difference coefficient using the Lorentz curve principle, this method can accurately assess the non-uniformity of fracture propagation. Based on this assessment result, fracturing stimulation schemes can be dynamically adjusted, thereby effectively improving unstable fracture propagation and enabling more uniform fracture propagation in the reservoir. This method can improve fracture propagation uniformity, increase fracturing fluid utilization efficiency, increase the swept volume of the fracturing network, provide real-time guidance for scheme adjustments, and improve single-well productivity.

[0021] This application also proposes a real-time control system for uniform fracture propagation in shale oil reservoirs, an electronic device, and a computer storage medium, which possess all the advantages of the aforementioned real-time control method for uniform fracture propagation in shale oil reservoirs. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the Lorentz curve in the invention. Figure 2 The second segment of the Lorentz curve is shown in a specific embodiment of the present invention; Figure 3 The Lorentz curve before temporary plugging fracturing in the 15th segment of a specific embodiment of the present invention; Figure 4 The Lorentz curve after temporary plugging fracturing in the 15th segment of a specific embodiment of the present invention; Figure 5 The Lorentz curve before temporary plugging fracturing in the 17th segment of a specific embodiment of the present invention; Figure 6 The Lorentz curve after temporary plugging fracturing in the 17th stage of a specific embodiment of the present invention; Figure 7 This is a flowchart of the real-time control method for uniform fracture propagation in shale oil reservoirs according to the present invention. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0025] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0026] Shale oil reservoirs typically exhibit low porosity and permeability. During hydraulic fracturing to stimulate shale oil reservoirs, problems arise such as severe single-fracture advance, low fracturing fluid fracture-forming efficiency, and small fracture network sweep volume. Severe single-fracture advance refers to the excessive expansion of a cluster of fractures in a specific direction within the fracturing section, forming a single long and narrow fracture. This advance not only reduces fracture propagation efficiency but also makes it difficult for fracturing fluid to distribute evenly throughout the reservoir, thus affecting fracturing effectiveness. Fracturing fluid fracture-forming efficiency refers to the ability of fracturing fluid to form fractures in the reservoir. The fracture network sweep volume refers to the size of the area covered by the extended fracturing fractures in the reservoir. These problems prevent the effective extraction of significant oil and gas resources from the reservoir, thereby reducing development efficiency and economic benefits. To address this issue, this application provides a real-time method for uniformly controlling fracture propagation in shale oil reservoirs.

[0027] This application discloses a method for real-time control of uniform fracture propagation in shale oil reservoirs, comprising the following steps: The number of fracturing stages and clusters in the target well is determined based on shale oil reservoir conditions. The fracture propagation difference coefficient is calculated by combining fracture fluid absorption profile information and the Lorentz curve principle. The fracture propagation state is evaluated based on the fracture propagation difference coefficient. The fracturing stimulation scheme is dynamically adjusted based on the evaluation results, and the stimulation effect is evaluated in real time.

[0028] This application utilizes real-time monitoring of fracture fluid absorption profiles and the Lorentz curve principle to calculate the fracture propagation difference coefficient, enabling accurate assessment of fracture non-uniformity. Based on this assessment, fracturing stimulation schemes can be dynamically adjusted, effectively mitigating unstable fracture propagation and promoting more uniform fracture propagation within the reservoir. This allows fracturing fluid to enter each fracture cluster evenly, preventing excessive penetration into individual fractures and improving fracturing fluid utilization efficiency. Furthermore, optimizing fracture propagation helps form a more complex and extensive fracture network. This not only improves reservoir permeability but also increases the swept volume of the fracture network, thereby increasing oil and gas resource extraction efficiency. The method provides real-time assessment results of fracture propagation status, providing strong support for the dynamic adjustment of fracturing stimulation schemes. This means that adjustments can be made promptly based on actual conditions during fracturing operations to ensure expected results. By improving fracture propagation status, increasing fracturing fluid utilization efficiency, and expanding the swept volume of the fracture network, this method is expected to significantly increase single-well productivity. This is of great significance for improving oil and gas resource extraction efficiency and economic benefits.

[0029] Example 1 A method for real-time control of uniform fracture propagation in shale oil reservoirs includes the following steps: Step 1: Obtain the reservoir parameters of the target well, and divide the target well into fracturing clusters based on the reservoir parameters, and determine the fracturing sections and the clusters of each fracturing section.

[0030] A fracturing section refers to several independent fracturing construction units into which the reservoir of the target well is divided according to reservoir parameters during hydraulic fracturing operations. Each fracturing section has a certain length and width.

[0031] A cluster refers to a smaller fracturing construction unit that is further refined and set up in each fracturing section in order to form a complex fracture network.

[0032] Reservoir parameters include reservoir physical properties, geological parameters, rock mechanics parameters, and geostress parameters.

[0033] Reservoir physical and geological parameters include well logging interpretation data.

[0034] Rock mechanics parameters include Young's modulus, Poisson's ratio, and brittleness index.

[0035] Geostress parameters include the magnitude and direction of geostress.

[0036] Step 2: Based on the fracturing segment clusters divided in Step 1, perform segment-by-segment perforation fracturing on each fracturing segment.

[0037] Perforation is carried out in each fracturing section. Perforation involves using tools such as perforating guns to create a certain number and diameter of holes in the well wall so that fracturing fluid can smoothly enter the reservoir and form fractures. The perforation operation needs to be determined according to the reservoir characteristics and fracturing design requirements.

[0038] After perforation is completed, fracturing operations can begin. Fracturing is the process of injecting high-pressure fracturing fluid into the well to cause the reservoir rock to fracture and form a network of fractures. During fracturing, parameters such as the injection rate, injection pressure, and injection volume of the fracturing fluid are controlled to ensure that the fractures propagate in the expected direction and extent.

[0039] Stage-by-stage perforation fracturing ensures that each fracturing stage is fully stimulated, thereby improving reservoir permeability and fluid flow. Stage-by-stage fracturing also avoids mutual interference and disruption between different fracturing stages, ensuring the effectiveness and safety of the fracturing operation.

[0040] Step 3: Based on the fluid absorption state of each cluster of fractures in the fracturing section and in conjunction with the Lorentz curve principle, determine the fracture propagation difference coefficient to evaluate the degree of non-uniform fracture propagation.

[0041] During the fracturing process, the fluid absorption profile of the target fracturing section is monitored in real time. Generally, the fluid absorption profile of the fracture is positively correlated with the fracture extension length. Therefore, the fracture propagation difference coefficient is determined based on the fluid absorption information of each cluster of fractures and the Lorentz curve principle to evaluate the degree of non-uniform fracture propagation.

[0042] A fluid uptake profile refers to the uptake of fracturing fluid at different locations within a reservoir, reflecting the distribution and propagation of fractures. Real-time monitoring of the fluid uptake profile allows for the acquisition of information such as the amount and rate of fluid uptake at different times and locations. This information can be used to assess fracture propagation and determine its extension status.

[0043] The Lorenz curve is a graphical tool in economics used to describe the degree of income inequality. In fracturing operations, this application applies the principle of the Lorenz curve to the evaluation of fracture propagation uniformity.

[0044] The fluid absorption of each cluster of fractures within the target fracturing section is sorted in ascending order. The proportion of the cumulative fluid absorption of each cluster of fractures to the total fluid absorption of the preceding clusters of fractures is calculated and used as the vertical axis. The ratio of the sequence number of each cluster of fractures to the total number of clusters is calculated and used as the horizontal axis. A curve is plotted on the coordinate system to obtain the Lorentz curve.

[0045] Then, the crack propagation difference coefficient is calculated based on the Lorenz curve to quantify the non-uniformity of crack propagation. The crack propagation difference coefficient is obtained by comparing the area difference between the Lorenz curve and the uniform distribution line. The larger the area difference, the stronger the non-uniformity of crack propagation, and the larger the crack propagation difference coefficient.

[0046] The degree of non-uniform crack propagation is evaluated using the crack propagation difference coefficient. A small crack propagation difference coefficient (close to 0) indicates relatively uniform crack propagation; a large crack propagation difference coefficient (close to 1) indicates significant non-uniformity in crack propagation.

[0047] The method used for the crack propagation difference coefficient in this embodiment is as follows: S3.1. Real-time acquisition of the fluid absorption q of the i-th fracture within the target fracturing section. i (i=0,1,...,n), let q i Sort the fractures in ascending order and express the sorted fluid absorption as q. i,k (k=0,1,···,n); S3.2 Calculate the cumulative fluid absorption Q of the k fractures before the target fracturing section. k (k=0,1,···,n); (1) S3.3 Calculate the cumulative fluid absorption percentage P(Q) of the k fractures before the target fracturing section. k (k=0,1,···,n); (2) S3.4 Calculate the cumulative fracture percentage P(k) of the k fractures before the target fracturing section (k=0,1,···,n); (3) S3.5. Draw an absolutely uniform line of crack propagation. The x and y coordinates of the points forming the curve are calculated as follows: (4) S3.6. Draw the Lorentz curve for evaluating the non-uniform propagation of cracks. The x and y coordinates of the points constituting the curve are calculated as follows: (5) S3.7 Calculate the crack propagation difference coefficient based on the horizontal and vertical coordinates of the absolutely uniform crack propagation line and the horizontal and vertical coordinates of the Lorenz curve of non-uniform crack propagation.

[0048] (6) Step 4: Evaluate the fracturing fracture extension effect in real time based on the fracture extension difference coefficient, dynamically adjust the fracturing modification scheme based on the evaluation results, and evaluate the fracture control effect in real time based on the new fracture extension difference coefficient.

[0049] During fracturing operations, by monitoring and recording the fluid absorption of each cluster of fractures in real time, and by calculating the fracture propagation difference coefficient using the Lorentz curve principle, the coefficient can be interpreted to evaluate the propagation effect of the fracturing fractures in real time.

[0050] Interpretation of the crack propagation difference coefficient: The smaller the crack propagation difference coefficient, the more similar the liquid absorption of each cluster of cracks is, and the more uniform the crack propagation is; conversely, the larger the coefficient, the more significant the non-uniformity of crack propagation.

[0051] Evaluation of extension effect: Based on the interpretation of the fracture extension difference coefficient, the extension effect of hydraulic fractures can be quantitatively evaluated. If the extension effect is good, that is, the fractures extend uniformly, then the reservoir permeability will be effectively improved, and the fluid flow will also be enhanced.

[0052] Based on the real-time evaluation of fracture extension, the fracturing modification scheme can be dynamically adjusted to optimize the fracture extension state and improve the effectiveness of fracturing operations.

[0053] After adjusting the fracturing stimulation scheme, the effectiveness of the fracture control needs to be evaluated in real time. This is achieved by re-monitoring the fluid absorption of each fracture cluster and recalculating the fracture propagation difference coefficient. Comparing the adjusted fracture propagation difference coefficient with the original coefficient allows for the assessment of the effectiveness of the control measures. If the coefficient decreases, it indicates that the control measures have achieved a positive effect; if the coefficient remains high, further adjustments to the scheme may be necessary, and step 2 should be repeated to calculate the fracture propagation difference coefficient until the fracture propagation is more uniform.

[0054] In this embodiment, the fracturing modification scheme is dynamically adjusted based on the evaluation results as an example.

[0055] 1. When the crack propagation difference coefficient G < 0.3, it indicates that the crack propagation is relatively uniform, and there is no need to perform temporary plugging fracturing to promote the initiation of new cracks; 2. When the crack propagation difference coefficient is 0.3 < G < 0.4, it indicates that the uniformity of crack propagation is at a medium level. The amount of temporary plugging ball is designed to be 1.5 times the number of holes. Fracturing by dropping balls promotes the initiation of new cracks. Then, repeat step 3 and evaluate the extension effect of cracks after control in real time. 3. When the crack propagation difference coefficient G≥0.4, it indicates that the crack propagation non-uniformity is high. The amount of temporary plugging ball is designed to be 1.2 times the number of holes. The ball is used to promote the initiation of new cracks through fracturing. Then, step 3 is repeated to evaluate the extension effect of the crack after control in real time.

[0056] Example 2 The target wells described below employ the real-time control method for uniform fracture propagation proposed in this application to dynamically adjust the fracturing stimulation scheme and evaluate the stimulation effect in real time during the fracturing process.

[0057] The reservoir is a tight, low-porosity, highly heterogeneous shale oil reservoir with a horizontal section of 2500-3600m. Based on reservoir properties, geology, rock mechanics, and in-situ stress parameters, a fracturing design of 20 sections and 61 clusters was optimized. Perforation fracturing was carried out section by section according to the section / cluster division results. Specifically, the second section was designed with 3 clusters and a length of 12m. 3 / min displacement, 29 orifices per section; Section 15 is designed with 4 clusters and 14m 3 / min discharge rate, 37 orifices per section; Section 17 is designed with 5 clusters and 15m 3 / min displacement, 46 holes per section.

[0058] The fracture fluid absorption profile monitored in real time after the second fracturing stage is shown in Table 1, and the Lorentz curves are shown in the figure. Figure 2 As shown, the calculated crack propagation difference coefficient is G=0.23<0.3, indicating that the crack propagation is relatively uniform and there is no need to perform temporary plugging fracturing to promote the initiation of new cracks.

[0059] Table 1. Statistical table of fluid absorption profile in the second fracture segment.

[0060] The fracture fluid absorption profile monitored in real time after the 15th fracturing stage is shown in Table 2, and the Lorentz curve is shown in the figure. Figure 3 As shown, the calculated crack propagation difference coefficient was 0.3 < G = 0.36 < 0.4, indicating that the uniformity of crack propagation was at a moderate level. The designed amount of temporary plugging balls was 1.5 times the number of holes, i.e., 44 temporary plugging balls were used to promote the initiation of new cracks. The crack fluid absorption profile monitored in real time after temporary plugging fracturing is shown in Table 3, and the Lorentz curve is shown in Table 4. Figure 4 As shown, it can be seen that after temporary plugging fracturing, the area formed by the Lorentz curve of non-uniform fracture propagation and the line of absolute uniform fracture propagation is significantly reduced, and the fracture propagation difference coefficient is reduced to G=0.23<0.3. This indicates that after using the real-time control method for uniform fracture propagation provided by this patent to dynamically adjust the fracturing modification scheme, the underdeveloped fractures are improved to a certain extent.

[0061] Table 2. Statistics of fluid absorption profile of fracture before temporary plugging fracturing in section 15.

[0062] Table 3. Statistics of fluid absorption profile of fracture after temporary plugging fracturing in section 15.

[0063] The fracture fluid absorption profile monitored in real time after the 17th fracturing stage is shown in Table 4, and the Lorentz curve is shown in the figure. Figure 5 As shown, the calculated crack propagation difference coefficient was G=0.43>0.4, indicating a high degree of non-uniformity in crack propagation. The designed amount of temporary plugging balls was 1.2 times the number of boreholes, i.e., 55 temporary plugging balls were used to promote new crack initiation. The crack fluid absorption profile monitored in real-time after temporary plugging fracturing is shown in Table 5, and the Lorentz curve is shown in... Figure 6 As shown, it can be seen that after temporary plugging fracturing, the area formed by the Lorentz curve of non-uniform crack propagation and the line of absolute uniform crack propagation is significantly reduced, and the crack propagation difference coefficient is reduced to G=0.24<0.3. This indicates that after using the real-time control method for uniform crack propagation provided by this patent to dynamically adjust the fracturing modification scheme, the underdeveloped cracks are improved to a certain extent.

[0064] Table 4. Statistics of fluid absorption profile of fracture before temporary plugging fracturing in section 17.

[0065] Table 5. Statistics of fluid absorption profile of fracture after temporary plugging fracturing in section 17.

[0066] In this Example 2, after adjusting the scheme using the real-time control method for uniform fracture propagation in shale oil reservoirs proposed in this application, the fracture propagation difference coefficient was significantly reduced, the non-uniformity of fracture propagation was reduced, and the oil production of the target well increased by 2 times compared with the previous stage. It can be seen that the real-time control method for uniform fracture propagation provided by this patent can not only intuitively, quantitatively and accurately evaluate the fracture propagation situation, but also control the fracture propagation state of shale oil reservoir fracturing in real time, laying a good foundation for improving production and efficiency of this type of reservoir.

[0067] The real-time control method for uniform fracture propagation in shale oil reservoirs proposed in this application can not only quantitatively characterize the degree of non-uniformity in fracture propagation, but also guide the adjustment of treatment schemes and evaluate the effects of stimulation in real time, achieving precise and real-time control of underdeveloped fractures. This technology overcomes the shortcomings of existing technologies and has broad applicability. This method is not only applicable to shale oil reservoirs, but can also be extended to other types of oil and gas reservoirs. Based on the concept of real-time monitoring and dynamic adjustment, it provides a new, more flexible, and efficient solution for oil and gas resource development.

[0068] In summary, this method has significant advantages in improving fracture propagation uniformity, increasing fracturing fluid utilization efficiency, increasing the swept volume of the fracturing network, providing real-time guidance for scheme adjustment, and improving single-well productivity, thus providing a new and more effective technical means for the development of oil and gas resources.

[0069] The following are embodiments of the apparatus of the present invention, which can be used to execute embodiments of the method of the present invention. For details not disclosed in the apparatus embodiments, please refer to the embodiments of the method of the present invention.

[0070] Example 3 Based on the above-mentioned method for real-time control of uniform fracture propagation in shale oil reservoirs, this application also proposes a real-time control system for uniform fracture propagation in shale oil reservoirs, which may include: The first module is used to determine the fracturing section and corresponding cluster of the target well based on shale oil reservoir parameters, obtain the fluid absorption profile information of each cluster of fractures in each fracturing section during the fracturing process, and calculate the fracture propagation difference coefficient by combining the Lorentz curve principle. The second module is used to evaluate the fracture propagation state based on the fracture propagation difference coefficient, dynamically adjust the fracturing stimulation scheme based on the evaluation results, and evaluate the stimulation effect in real time.

[0071] All relevant content of each step involved in the aforementioned embodiments of the real-time control method for uniform fracture propagation in shale oil reservoirs can be referenced from the functional description of the corresponding functional module of the real-time control system for uniform fracture propagation in shale oil reservoirs in the embodiments of the present invention, and will not be repeated here.

[0072] The module division in this embodiment of the invention is illustrative and represents only one logical functional division. In actual implementation, other division methods may be used. Furthermore, the functional modules in the various embodiments of the invention can be integrated into a single processor, exist as separate physical entities, or be integrated into a single module. The integrated modules described above can be implemented in hardware or as software functional modules.

[0073] In another embodiment of the present invention, a computer device is provided, comprising a processor and a memory. The memory stores a computer program, which includes program instructions. The processor executes the program instructions stored in the computer storage medium. The processor may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing and control core of the terminal, suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions in the computer storage medium to achieve a corresponding method flow or corresponding function. The processor described in this embodiment of the present invention can be used in the operation of a real-time control method for uniform fracture propagation in shale oil reservoirs.

[0074] In another embodiment of the present invention, a storage medium is provided, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device used to store programs and data. It is understood that the computer-readable storage medium here can include both the built-in storage medium in the computer device and extended storage media supported by the computer device. The computer-readable storage medium provides storage space that stores the terminal's operating system. Furthermore, the storage space also stores one or more instructions suitable for loading and execution by a processor. These instructions can be one or more computer programs (including program code). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk storage device. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the corresponding steps of the real-time control method for uniform fracture propagation in shale oil reservoirs in the above embodiments.

[0075] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0076] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0077] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0078] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0079] For descriptions of relevant parts of the real-time control system, electronic equipment, and computer-readable storage medium for uniform fracture propagation in shale oil reservoirs provided in this application, please refer to the detailed descriptions of the corresponding parts in the real-time control method for uniform fracture propagation in shale oil reservoirs provided in this application, which will not be repeated here. Furthermore, parts of the technical solutions provided in this application that are consistent with the implementation principles of corresponding technical solutions in the prior art have not been described in detail to avoid excessive elaboration.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for real-time control of uniform fracture propagation in shale oil reservoirs, characterized in that, Includes the following processes: Based on shale oil reservoir parameters, the fracturing section and corresponding cluster of the target well are determined, the fluid absorption profile information of each cluster of fractures in each fracturing section is obtained during the fracturing process, and the fracture propagation difference coefficient is calculated by combining the Lorentz curve principle. The fracture propagation status is evaluated based on the fracture propagation difference coefficient, and the fracturing stimulation scheme is dynamically adjusted based on the evaluation results, with the stimulation effect evaluated in real time.

2. The method for real-time control of uniform fracture propagation in shale oil reservoirs according to claim 1, characterized in that, The shale oil reservoir parameters include the reservoir's physical properties, geological parameters, rock mechanics parameters, and geostress parameters.

3. A method for real-time control of uniform fracture propagation in shale oil reservoirs according to claim 1 or 2, characterized in that, The calculation of the crack propagation difference coefficient includes: Lorentz curves are constructed based on the ratio of the total fluid absorption of each cluster of fractures within the target fracturing section to the cumulative fluid absorption of each cluster of fractures in all fracturing sections preceding the target fracturing section. The fracture propagation difference coefficient is determined based on the Lorentz curves to quantify the non-uniformity of fracture propagation.

4. The method for real-time control of uniform fracture propagation in shale oil reservoirs according to claim 3, characterized in that, The method for constructing the crack propagation difference coefficient includes: The fluid absorption of each cluster of fractures within the target fracturing section is sorted from smallest to largest. The ratio of the cumulative fluid absorption of each cluster of fractures to the total fluid absorption of the preceding clusters is calculated, as well as the ratio of the sequence number of each cluster of fractures to the total number of clusters. Based on these two ratios, an absolute uniformity line and a Lorentz curve for non-uniform fracture propagation are plotted. The fracture propagation difference coefficient is determined based on the coordinates of the absolute uniformity line and the Lorentz curve.

5. A method for real-time control of uniform fracture propagation in shale oil reservoirs according to claim 1 or 4, characterized in that, The expression for the crack propagation difference coefficient is as follows: in, k The sequence number is used to sort each cluster of fractures within the target fracturing section according to the amount of fluid absorbed. Q k The cumulative fluid absorption of the target fracturing section. P ( Q k The percentage represents the ratio of the total liquid uptake of each fracture cluster to the total liquid uptake of all preceding fracture clusters. P ( k The ratio of the sequence number of each crack cluster to the total number of clusters is denoted as . X 均匀 = P ( k ), Y 均匀 = P ( k The x and y coordinates of the crack propagation uniformity line are respectively: X 均匀 = P ( k ), Y 均匀 = P ( Q k (x) represents the horizontal and vertical coordinates of the Lorentz curve for non-uniform crack propagation.

6. The method for real-time control of uniform fracture propagation in shale oil reservoirs according to claim 1, characterized in that, The crack propagation difference coefficient is used to evaluate the crack propagation state, including: Multiple evaluation thresholds are set to characterize different crack propagation states. The crack propagation difference coefficient is compared with the evaluation thresholds to determine the crack propagation state.

7. The method for real-time control of uniform fracture propagation in shale oil reservoirs according to claim 6, characterized in that, The dynamically adjusted fracturing scheme includes: The first approach is that when the crack propagation difference coefficient is less than the first threshold, the crack propagation is relatively uniform. The second approach is to initiate new cracks by ball-drop fracturing when the crack propagation difference coefficient is greater than the first threshold and less than the second threshold. The third option is to initiate new cracks by ball-drop fracturing when the crack propagation difference coefficient is greater than or equal to the third threshold. The first threshold, the second threshold, and the third threshold increase sequentially; the number of pitches in the third scheme is less than the number of pitches in the second scheme.

8. A real-time control system for uniform fracture propagation in shale oil reservoirs, characterized in that, include: The first module is used to determine the fracturing section and corresponding cluster of the target well based on shale oil reservoir parameters, obtain the fluid absorption profile information of each cluster of fractures in each fracturing section during the fracturing process, and calculate the fracture propagation difference coefficient by combining the Lorentz curve principle. The second module is used to evaluate the fracture propagation state based on the fracture propagation difference coefficient, dynamically adjust the fracturing stimulation scheme based on the evaluation results, and evaluate the stimulation effect in real time.

9. An electronic device, characterized in that, include: Memory, used to store computer programs; A processor is configured to execute the computer program to implement the steps of the real-time control method for uniform fracture propagation in shale oil reservoirs as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of the real-time control method for uniform fracture propagation in shale oil reservoirs according to any one of claims 1-7.

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