Three-dimensional fracturing design method, system and equipment, processor and storage medium

Abstract

The invention provides a three-dimensional fracturing design method, system and equipment, a processor and a storage medium, and belongs to the technical field of reservoir exploitation. The method comprises the following steps: determining a design stress field required by a reconstruction area to reach a crack required distribution state; comparing the difference between the design stress field and the original crustal stress field to determine an area in which the high-stress barrier needs to be manufactured, performing high-stress barrier manufacturing parameter design on the area, and then changing at least one of the high-stress barrier manufacturing parameters and fracturing parameters determined according to actual demands of all cracks in the crack demand distribution form; and / or, reducing the crack demand, repeatedly utilizing the constructed stress interference calculation model to calculate the crack stress interference range and degree, and if the difference between the actual stress field and the design stress field after the crack interference is generated is within a first preset range and the conformity between the actual crack form and the crack demand distribution form is within a second preset range, determining that the crack interference is generated. And if the pressure channeling does not exist, the latest fracturing parameters are used as fracturing construction parameters.

Description

Technical Field

[0001] The present invention belongs to the technical field of reservoir exploitation, particularly to the technical field of fracturing design for oil and gas and geothermal reservoirs, and specifically relates to a three-dimensional fracturing design method, system, equipment, processor, and storage medium based on artificial stress interference. Background Art

[0002] With the increasing difficulty of oil and gas reservoir exploration and development, it is difficult to improve the oil and gas production construction speed. It has gradually changed from the independent development of a single layer to the three-dimensional development of multiple layers. Fracturing technology is one of the key technologies to ensure the rapid production construction of such reservoirs.

[0003] Currently, with the development of fracturing technology, the fracturing technology has been rapidly upgraded and replaced, and the technical indicators have also been continuously improved. For example, the "volume fracturing" concept and technology with the "horizontal well segmented fracturing + temporary plugging process" as the core. The existing "volume fracturing" technology has achieved some results in the fracturing transformation of single-layer single-well or multi-well in the same layer of shale gas reservoirs. However, this technology still has the following obvious defects and limitations: 1) It is mainly applicable to reservoirs with well-developed natural fractures, high brittleness index, and small horizontal stress difference. Since the concept of this technology is to "break the reservoir" by pumping fracturing fluid at a large displacement and form a "fracture network" through the interaction between hydraulic fractures and natural fractures, it has limitations for other oil and gas reservoirs with underdeveloped natural fractures, low brittleness index, large horizontal stress difference, or different fracture morphology requirements, such as shale oil, tight gas, etc. Such reservoirs cannot form a "fracture network" under the above concept, indicating that the applicable range of this technology is limited; 2) The in-situ stress field is an important factor affecting the extension path of hydraulic fractures. When designing fracturing parameters for the existing "volume fracturing", it still only passively accepts the stress field without designing and controlling the stress field, and thus cannot control the extension path of hydraulic fractures. The fracture extension may have adverse situations such as being too long, too short, too large or too small fracture height, connecting adjacent wells or communicating with water layers. Therefore, under the existing fracturing design methods and technical conditions, there are still untransformed areas in the reservoir, and fracturing crossflow occurs in some sections, resulting in inefficient reservoir transformation or transformation failure.

[0004] To reduce the risk of fracturing crossflow, currently mature solutions mostly adopt methods such as avoiding natural fractures and temporary plugging with temporary plugging agents, but the actual effect is very limited. The method of avoiding natural fractures usually reduces the transformation range of high-quality reservoirs, and the existence of natural fractures itself is a stress weak area. If the avoidance distance is too large, the loss is high, and if the avoidance distance is insufficient, the anti-fracturing crossflow effect is limited. The method of temporary plugging with temporary plugging agents is difficult to ensure that the temporary plugging agent migrates to the crack tip and forms sufficient stress to hinder the crack extension.

[0005] It can be seen that the extension path of the fracture system formed by the above fracturing and reconstruction technology applied to single-layer single-well or single-layer same-well is uncontrollable, resulting in insufficient release of reservoir productivity. At the same time, downhole complexities such as fracturing and channeling also exist, resulting in "unreconstructed areas", "repeatedly reconstructed areas" and "inefficiently reconstructed areas", and there is still no design method for multi-layer multi-well three-dimensional fracturing (new well production or old well potential tapping), resulting in limited production increase capacity.

[0006] For multi-layer multi-well fracturing, it is necessary to consider different sedimentary depths, relatively thin reservoir thicknesses, and the presence of water layers. Therefore, it is more necessary to scientifically design and control the extension path and shape of fractures. Existing horizontal well staged fracturing technology and fracturing design methods are not applicable to multi-layer multi-well fracturing and reconstruction. The current mature means of controlling fracture height is mainly the artificial barrier technology. The basic principle of controlling fracture height with an artificial barrier is to add floating or sinking proppants to the pad fluid, and bring them into the fracture through the pad fluid. The floating proppants and sinking proppants float and sink respectively and gather at the top and bottom of the fracture to form a compacted low-permeability artificial barrier, preventing the pressure in the fracture from propagating upward and downward to achieve the purpose of controlling fracture height. However, due to the small amount of fluid used in the pad fluid stage and the limited fracture length, the placement range of the proppants used to create the artificial barrier is limited, and the hydraulic fracture is very likely to continue to extend across the artificial barrier, especially when there is a low-stress area, it is more likely to lead to fracturing failure, and the applicability is low.

[0007] In addition, when the current horizontal well staged fracturing technology and fracturing design method are applied to the fracturing of geothermal reservoirs, the above limitations or deficiencies also exist.

[0008] Therefore, for efficient reconstruction in scenarios such as Figure 1 the multi-well in the same layer of oil and gas reservoirs shown, Figure 2 the multi-well in the same layer of geothermal reservoirs shown, and Figure 3 the multi-layer multi-well of oil and gas reservoirs shown, to achieve scientific design and control of the fracture propagation extension path and shape, an improved three-dimensional fracturing design method is urgently needed to be proposed. Summary of the Invention

[0009] The purpose of the embodiments of the present invention is to provide a three-dimensional fracturing design method, system, device, processor, and storage medium to solve the technical problems that the existing horizontal well staged fracturing technology and fracturing design method have poor reconstruction effects on multi-well in the same layer and are not applicable to multi-layer multi-well reconstruction.

[0010] To achieve the above purpose, the first aspect of the embodiments of the present invention provides a three-dimensional fracturing design method, and the method includes:

[0011] S100. Determine the stress field required for the fracture demand distribution state to be reached in the target well reconstruction area, and this stress field is the design stress field;

[0012] S200. After comparing the differences between the designed stress field and the original in-situ stress field, determine whether there is an area where a high-stress barrier needs to be created. If so, execute S300; otherwise, execute S400;

[0013] S300. Design the manufacturing parameters of the high-stress barrier for the area where the high-stress barrier needs to be created;

[0014] S400. Combining the design parameters, use the stress interference calculation model constructed for multi-dimensional induced stress calculation to calculate the stress interference range and degree of multiple fractures. If the first preset condition is met, use this design parameter as the parameter for fracturing construction in the target well reconstruction area; otherwise, under the premise of changing the design parameter and / or reducing the fracture requirement, repeatedly use the stress interference calculation model to calculate the stress interference range and degree of multiple fractures until the first preset condition is met, and use the latest design parameter as the parameter for fracturing construction in the target well reconstruction area;

[0015] The first preset condition is: the difference between the actual stress field after fracture interference and the designed stress field is within the first preset range, the compliance between the actual fracture morphology within the calculation range and the distribution morphology of the fracture requirement is within the second preset range, and there is no fracturing breakthrough;

[0016] The design parameters include fracturing parameters, and when there is an area where a high-stress barrier needs to be created, they also include high-stress barrier manufacturing parameters;

[0017] The fracturing parameters are determined according to the actual requirements of each fracture in the fracture requirement distribution morphology.

[0018] Optionally, the process of the stress interference calculation model calculating the stress interference range and degree is as follows:

[0019] Combining the seismic data interpretation results and the indoor core experiment data, conduct macroscopic and microscopic nested characterization of the reservoir heterogeneity;

[0020] Using the damage mechanics and fluid-solid coupling fracture propagation model to calculate the stress interference range and degree of fractures under different conditions.

[0021] Optionally, in step S100, determine the stress field required for the target well reconstruction area to reach the fracture requirement distribution state, and this stress field is the designed stress field, including:

[0022] S101. Calculate and simulate the hydraulic fracture morphology based on the original in-situ stress field;

[0023] S102. Combining the reservoir structure characteristics and sedimentary characteristics of the reconstruction area, determine the fracture requirement distribution morphology that meets the second preset condition, and the second preset condition includes no fracturing breakthrough and maximizing the utilization of the formation;

[0024] S103. Calculate the stress field required to form the crack demand distribution pattern, which is the designed stress field.

[0025] Optionally, step S400 includes:

[0026] S401. Determine the current fracturing parameters according to the actual demands of each crack in the crack demand distribution pattern;

[0027] S402. Combine the current fracturing parameters and, based on the stress interference calculation model constructed for multi-dimensional induced stress calculation, calculate the actual stress field generated after all cracks in the crack demand distribution pattern are formed. If there is a region where a high-stress barrier needs to be created, add the stress interference generated after the creation of the high-stress barrier in this region to the actual stress field;

[0028] S403. Determine whether the difference between the actual stress field and the designed stress field is within the first preset range. If so, proceed to the next step; otherwise, determine that a high-stress barrier needs to be created and jump to S300. When the cumulative number of jumps reaches the first threshold, jump to S100;

[0029] S404. Determine whether the compliance between the actual crack pattern and the crack demand distribution pattern is within the second preset range. If so, proceed to the next step; otherwise, jump to S100;

[0030] S405. Determine whether there is cross-fracturing. If so, jump to S100; otherwise, use the latest fracturing parameters as the parameters for fracturing the target well's transformation area. When there is a region where a high-stress barrier needs to be created, also use the latest high-stress barrier creation parameters as the parameters for fracturing the target well's transformation area.

[0031] Optionally, macroscopically and microscopically nested characterization of reservoir heterogeneity is carried out by combining seismic data interpretation results and indoor core experiment data. The specific process is as follows:

[0032] Perform geological modeling based on seismic geophysical data, that is, the first assignment of the grid;

[0033] Use the weakening of rock mechanical properties to characterize discontinuity surfaces, where discontinuity surfaces include faults and natural fractures;

[0034] Determine the values of each parameter of the Weibull function based on well logging interpretation results and indoor core experiment data;

[0035] Based on the determined Weibull function, perform a secondary assignment to each grid of the geological model separately to complete the macroscopic and microscopic nested modeling.

[0036] Optionally, in S300, when a high-stress barrier area needs to be created in a multi-well environment on the same layer and there is a low-stress area in adjacent wells, the specific process of designing the high-stress barrier manufacturing parameters for this area is as follows:

[0037] Obtain the stress field difference after comparing the in-situ stress of adjacent wells with that of the target well's transformation area;

[0038] Combined with the stress interference calculation model already constructed for multi-dimensional induced stress calculation, calculate the required multi-fracture stress interference range and degree based on the stress field difference and the hydraulic fracture morphology of adjacent wells, and determine the liquid viscosity and usage amount required to generate this stress interference range and degree, so as to facilitate the setting of a packer at the wellbore position corresponding to the low-stress area. Then, pump the liquid according to the liquid viscosity and usage amount and shut in the well, thereby completing the manufacturing of the high-stress barrier in this area.

[0039] Optionally, in S300, when a high-stress barrier area needs to be created in a multi-layer and multi-well environment where there is no high-stress interlayer between the upper and lower reservoirs, or natural fractures are developed, or the well spacing between the upper and lower wells is small, resulting in the possibility of hydraulic fracture connection between the upper and lower wells, the specific process of designing the high-stress barrier manufacturing parameters for this area is as follows:

[0040] Calculate the maximum safe fracture height of the hydraulic fractures in the upper well and the lower well that may be connected, or the maximum safe fracture height where the hydraulic fractures do not extend to the lower or upper layer, based on the interlayer distance or the spacing between the upper well and the lower well;

[0041] Calculate the fracture height of the hydraulic fractures in the upper well and the lower well, or the fracture height where the hydraulic fractures do not extend to the lower or upper layer, without artificial stress interference, and based on the difference between each fracture height and the corresponding maximum safe fracture height, calculate the required stress interference range and degree using the stress interference calculation model already constructed for multi-dimensional induced stress calculation;

[0042] Determine the fracturing parameters based on the calculated stress interference range and degree, so as to facilitate the fracturing construction in this area using these fracturing parameters, thereby completing the manufacturing of the high-stress barrier in this area.

[0043] Optionally, step S200 includes:

[0044] In the designed stress field and the original in-situ stress field, within a range of 200 m from the wellbore, compare the three parameters of each grid in each geological model. If the relative errors of the three parameters are all between -20% and 20%, it is determined that there is no area that needs to create a high-stress barrier at this time, and S400 is executed; otherwise, it is determined that there is an area that needs to create a high-stress barrier at this time, and S300 is executed;

[0045] The three parameters are the maximum horizontal principal stress σ max 、the minimum horizontal principal stress σmin and the horizontal stress difference ratio σ max / σ min .

[0046] Optionally, both the simulated hydraulic fracture shape and the required fracture distribution shape include fracture height, fracture length, and extension path.

[0047] Optionally, in S103, calculating the stress field required to form the required fracture distribution shape includes:

[0048] After comparing the differences between the simulated hydraulic fracture shape and the required fracture distribution shape, use damage mechanics and fluid-solid coupling fracture propagation models to calculate the stress field required to form the required fracture distribution shape.

[0049] Optionally, in S401, determining the current fracturing parameters according to the actual requirements of each fracture in the required fracture distribution shape includes:

[0050] S4011. Calculate the actual requirements of each fracture in the required fracture distribution shape according to the rock mechanical properties and the stress distribution shape of the drilled box body. The actual requirements include the fracture initiation position, geometric parameters, and extension path;

[0051] S4012. Based on the actual requirements of the fracture, determine the required current fracturing parameters. The fracturing parameters include perforation parameters and fracturing pumping parameters. The perforation parameters include perforation position, perforation density, and hole size.

[0052] Optionally, the first preset range is 0 to 20%.

[0053] Optionally, the second preset range is 80% to 100%.

[0054] Optionally, in S101, after calculating the simulated hydraulic fracture shape based on the original in-situ stress field, the result is corrected by on-site micro-injection testing.

[0055] The second aspect of the embodiments of the present invention provides a three-dimensional fracturing design system. The system includes a first comparison module, and the first comparison module is connected to a first determination module, a first design module, and a second determination module. The second determination module is also respectively connected to the first determination module and the first design module;

[0056] The first determination module is used to execute the first determination step;

[0057] The first determination step includes: determining the stress field required for the target well reconstruction area to reach the required fracture distribution state, and this stress field is the design stress field;

[0058] The first comparison module is used to determine whether there is an area where a high-stress barrier needs to be manufactured after comparing the differences between the designed stress field and the original in-situ stress field. If so, it enters the first design step; otherwise, it enters the second determination step.

[0059] The first design module is used to execute the first design step.

[0060] The first design step includes: designing the manufacturing parameters of the high-stress barrier for the area where the high-stress barrier needs to be manufactured.

[0061] The second determination module is used to execute the second determination step.

[0062] The second determination step includes:

[0063] Combined with the design parameters, using the stress interference calculation model constructed for multi-dimensional induced stress calculation to calculate the stress interference range and degree of multiple fractures. If the first preset condition is met, the design parameters are used as the parameters for fracturing construction in the target well reconstruction area; otherwise, on the premise of changing the design parameters and / or reducing the fracture requirements, the stress interference calculation model is repeatedly used to calculate the stress interference range and degree of multiple fractures until the first preset condition is met, and the latest design parameters are used as the parameters for fracturing construction in the target well reconstruction area.

[0064] The first preset condition is: the difference between the actual stress field after fracture interference and the designed stress field is within the first preset range, the conformity between the actual fracture morphology within the calculation range and the distribution morphology of fracture requirements is within the second preset range, and there is no fracturing breakthrough.

[0065] The design parameters include fracturing parameters, and when there is an area where a high-stress barrier needs to be manufactured, they also include high-stress barrier manufacturing parameters.

[0066] The fracturing parameters are determined according to the actual requirements of each fracture in the distribution morphology of fracture requirements.

[0067] Optionally, the process of the stress interference calculation model calculating the stress interference range and degree is as follows:

[0068] Combined with the results of seismic data interpretation and indoor core experiment data, the reservoir heterogeneity is characterized macroscopically and mesoscopically in a nested manner.

[0069] Using damage mechanics and fluid-solid coupling fracture propagation models to calculate the stress interference range and degree of fractures under different conditions.

[0070] Optionally, the specific process of the first determination module determining the stress field required for the target well reconstruction area to reach the fracture requirement distribution state is as follows:

[0071] Based on the original in-situ stress field, simulate the hydraulic fracture morphology.

[0072] Determine the crack demand distribution pattern that meets the second preset condition in combination with the reservoir characteristics of the reformed area. The second preset condition includes no fracturing channeling and maximizing the utilization of the formation system;

[0073] Calculate the stress field required to form the crack demand distribution pattern, and this stress field is the designed stress field.

[0074] Optionally, the second determination module includes a first calculation module, a second calculation module, a first judgment module, a second judgment module, and a third judgment module that are connected in sequence. The first judgment module is also connected to the first design module and the first determination module, and the second judgment module and the third judgment module are also respectively connected to the first determination module;

[0075] The first calculation module is used to execute the first calculation step;

[0076] The first calculation step includes: determining the current fracturing parameters according to the actual demands of each crack in the crack demand distribution pattern;

[0077] The second calculation module is used to execute the actual stress field calculation step;

[0078] The actual stress field calculation step includes: combining the current fracturing parameters and calculating the actual stress field generated after all cracks in the crack demand distribution pattern are formed based on the stress interference calculation model constructed for multi-dimensional induced stress calculation. If there is an area where a high-stress barrier needs to be created, the stress interference generated after creating the high-stress barrier in this area is added to the actual stress field;

[0079] The first judgment module is used to judge whether the difference between the actual stress field and the designed stress field is within the first preset range. If so, it enters the second judgment step; otherwise, it determines that a high-stress barrier needs to be created and jumps to the first design step. When the cumulative number of jumps reaches the first threshold, it jumps to the first determination step;

[0080] The second judgment module is used to execute the second judgment step;

[0081] The second judgment step includes:

[0082] Judging whether the conformity between the actual crack pattern and the crack demand distribution pattern is within the second preset range. If so, it enters the third judgment step; otherwise, it enters the first determination step;

[0083] The third judgment module is used to execute the third judgment step;

[0084] The third judgment step includes:

[0085] Determine whether there is cross - formation flow. If so, enter the first determination step; otherwise, use the latest fracturing parameters as the parameters for fracturing the target well's reformed area. When there is an area that requires creating a high - stress barrier, also use the latest high - stress barrier creation parameters as the parameters for fracturing the target well's reformed area.

[0086] Optionally, combine the results of seismic data interpretation and laboratory core experiment data to conduct macroscopic and microscopic nested characterization of reservoir heterogeneity. The specific process is as follows:

[0087] Conduct geological modeling based on seismic geophysical data, that is, the first assignment of the grid;

[0088] Use the weakening of rock mechanical properties to characterize discontinuity surfaces, where discontinuity surfaces include faults and natural fractures;

[0089] Determine the values of each parameter of the Weibull function based on well - logging interpretation results and laboratory core experiment data;

[0090] Based on the determined Weibull function, conduct a second assignment for each grid in the geological modeling separately to complete the macroscopic and microscopic nested modeling.

[0091] Optionally, when the area that requires creating a high - stress barrier is in an environment of multiple wells in the same layer and there is a low - stress area in the adjacent well, the specific process for designing the high - stress barrier creation parameters for this area is as follows:

[0092] Obtain the stress field difference after comparing the in - situ stress of the adjacent well with that of the target well's reformed area;

[0093] Combine the stress interference calculation model for multi - dimensional induced stress that has been constructed. According to the stress field difference and the hydraulic fracture morphology of the adjacent well, calculate the required multi - fracture stress interference range and degree, and determine the liquid viscosity and usage amount required to generate this stress interference range and degree. Then, lower a packer at the wellbore position corresponding to the low - stress area, and then pump in the liquid according to the liquid viscosity and usage amount and shut in the well to complete the creation of the high - stress barrier in this area.

[0094] Optionally, when the area that requires creating a high - stress barrier is in an environment of multiple wells in multiple layers and there is no high - stress interlayer between the upper and lower reservoirs, or natural fractures are developed, or the well spacing between the upper and lower wells is small, resulting in the possibility of hydraulic fracture connection between the upper and lower wells, the specific process for designing the high - stress barrier creation parameters for this area is as follows:

[0095] According to the inter - layer distance or the distance between the upper well and the lower well, calculate the maximum safe fracture height of the hydraulic fractures of the upper well and the lower well that may be connected, or the maximum safe fracture height at which the hydraulic fractures do not extend to the lower or upper layer;

[0096] Calculate the fracture height of the upper well hydraulic fracture and the lower well hydraulic fracture without artificial stress interference, or the fracture height when the hydraulic fracture does not extend to the lower or upper layer, and based on the difference between each fracture height and the corresponding maximum safe fracture height, calculate the required stress interference range and degree using the stress interference calculation model constructed for multi-dimensional induced stress calculation;

[0097] Determine the fracturing parameters according to the calculated stress interference range and degree, so as to use these fracturing parameters for the fracturing construction in this area, thereby completing the manufacture of the high-stress barrier in this area.

[0098] Optionally, after the first comparison module compares the differences between the designed stress field and the original in-situ stress field to determine whether there is an area where a high-stress barrier needs to be manufactured. If so, enter the first design step; otherwise, enter the second determination step, which specifically includes:

[0099] In the designed stress field and the original in-situ stress field, within a range of 200 m from the wellbore, compare the three parameters of each grid in each geological model. If the relative errors of the three parameters are all between -20% and 20%, it is determined that there is no area where a high-stress barrier needs to be manufactured at this time, and enter the second determination step; otherwise, it is determined that there is an area where a high-stress barrier needs to be manufactured at this time, and enter the first design step;

[0100] The three parameters are the maximum horizontal principal stress σ max , the minimum horizontal principal stress σ min and the horizontal stress difference ratio σ max / σ min .

[0101] Optionally, both the simulated hydraulic fracture shape and the required fracture distribution shape include fracture height, fracture length, and extension path.

[0102] Optionally, calculating the stress field required to form the required fracture distribution shape includes:

[0103] After comparing the differences between the simulated hydraulic fracture shape and the required fracture distribution shape, use the damage mechanics and fluid-solid coupling fracture propagation model to calculate the stress field required to form the required fracture distribution shape.

[0104] Optionally, determining the current fracturing parameters according to the actual requirements of each fracture in the required fracture distribution shape includes:

[0105] Calculate the actual requirements of each fracture in the required fracture distribution shape according to the rock mechanical properties and the stress distribution shape of the drilled box. The actual requirements include the fracture initiation position, geometric parameters, and extension path;

[0106] Based on the actual requirements of the fractures, determine the required current fracturing parameters. The fracturing parameters include perforation parameters and fracturing pumping parameters. The perforation parameters include perforation positions, perforation densities, and hole sizes.

[0107] Optionally, the first preset range is 0 to 20%.

[0108] Optionally, the second preset range is 80% to 100%.

[0109] Optionally, after calculating and simulating the hydraulic fracture morphology based on the original in-situ stress field, the results are corrected through on-site micro-injection tests.

[0110] A third aspect of the embodiments of the present invention provides a device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, it implements the three-dimensional fracturing design method as described in the first aspect of the embodiments of the present invention.

[0111] A fourth aspect of the embodiments of the present invention provides a processor for running a program. When the program runs, it executes the three-dimensional fracturing design method as described in the first aspect of the embodiments of the present invention.

[0112] A fifth aspect of the embodiments of the present invention provides a storage medium with a computer program stored thereon. When the computer program is executed by a processor, it implements the three-dimensional fracturing design method as described in the first aspect of the embodiments of the present invention.

[0113] The above technical solutions are based on the technical route of "designing and controlling the stress field", with the fracturing design concept of "optimizing the fracture propagation range of multi-layer multi-well or same-layer multi-well transformation". When designing the three-dimensional fracturing parameters, the traditional passive acceptance of the in-situ stress field is transformed into active design and control, thereby controlling the fracture path and morphology, that is, designing and controlling the in-situ stress field based on "artificial stress interference", so that the fracturing technology can be applied to same-layer multi-well and multi-layer multi-well, and the reservoir transformation range is expanded. Compared with using the traditional horizontal well segmented fracturing technology for fracturing transformation, applying the fracturing parameters designed by the present invention for three-dimensional fracturing construction operations can achieve efficient transformation of same-layer multi-well and multi-layer multi-well, and improve the stimulation effect. At the same time, parameter design is also carried out for the areas that need to create high-stress barriers, and high-stress barriers are constructed using the designed parameters, which can reduce downhole complexities such as crossflow between wells and crossflow between layers.

[0114] Other features and advantages of the embodiments of the present invention will be described in detail in the subsequent specific implementation section. Description of the Drawings

[0115] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention, and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the embodiments of the present invention, but do not constitute a limitation to the embodiments of the present invention. In the accompanying drawings:

[0116] Figure 1 It is a schematic diagram of multi-well production in the same layer of an oil and gas reservoir;

[0117] Figure 2 It is a schematic diagram of multi-well production in the same layer of a geothermal reservoir;

[0118] Figure 3 It is a schematic diagram of multi-well production in multiple layers of an oil and gas reservoir;

[0119] Figure 4 It is a schematic flow chart of a three-dimensional fracturing design method;

[0120] Figure 5 It is a schematic flow chart of the design of high-stress barrier manufacturing parameters in the environment of multi-wells in the same layer;

[0121] Figure 6 It is a schematic flow chart of the design of high-stress barrier manufacturing parameters in the environment of multi-wells in multiple layers;

[0122] Figure 7 It is a schematic flow chart of the calculation process of stress interference range and degree. Specific Embodiments

[0123] The following will describe in detail the specific embodiments of the embodiments of the present invention with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the embodiments of the present invention, and are not used to limit the embodiments of the present invention.

[0124] Method Embodiment

[0125] The present invention provides a three-dimensional fracturing design method, which is applied to the design of three-dimensional fracturing parameters in the reservoir of the target well reconstruction area, such as the fracturing parameter design in the environment of multi-well production in the same layer of an oil and gas reservoir, the fracturing parameter design in the environment of multi-well production in the same layer of a geothermal reservoir, and the fracturing parameter design in the environment of multi-well production in multiple layers of an oil and gas reservoir.

[0126] Specifically, referring to Figures 4 to 7 , the three-dimensional fracturing design method includes the following implementation steps:

[0127] S100. Determine the stress field required for the fracture demand distribution state to be achieved in the target well reconstruction area, and this stress field is the design stress field.

[0128] S200. After comparing the differences between the designed stress field and the original in-situ stress field, determine whether there is an area where a high-stress barrier needs to be created. If so, execute S300; otherwise, execute S400.

[0129] S300. Design the manufacturing parameters of the high-stress barrier for the area where the high-stress barrier needs to be created.

[0130] S400. Combine the design parameters and use the stress interference calculation model for multi-fracture stress interference calculation, which has been constructed for multi-dimensional induced stress calculation, to calculate the stress interference range and degree of multiple fractures. If the first preset condition is met, use these design parameters as the parameters for fracturing construction in the target well reconstruction area; otherwise, under the premise of changing the design parameters and / or reducing the fracture requirements, repeatedly use this stress interference calculation model to calculate the stress interference range and degree of multiple fractures until the first preset condition is met, and use the latest design parameters as the parameters for fracturing construction in the target well reconstruction area.

[0131] The above-mentioned first preset condition is: the difference between the actual stress field after fracture interference and the designed stress field is within the first preset range, and the conformity between the actual fracture pattern within the calculation range and the fracture requirement distribution pattern is within the second preset range, and there is no fracture breakthrough. The design parameters include fracturing parameters, and when there is an area where a high-stress barrier needs to be created, they also include high-stress barrier manufacturing parameters. The fracturing parameters are determined according to the actual requirements of each fracture in the fracture requirement distribution pattern. It can be known that the fracturing parameters generally include perforation parameters and fracturing pumping parameters. The perforation parameters specifically refer to: perforation location, perforation density, hole size, etc., and the fracturing pumping parameters include pumping displacement and liquid volume, etc.

[0132] In addition, the fracture requirement distribution pattern is the ideal fracture distribution pattern, and "artificial stress interference" control is carried out based on this ideal fracture distribution pattern. Reducing the fracture requirements means that after changing the design parameters multiple times, the stress interference after the formation of multiple fractures still cannot meet the first preset condition. At this time, the fracture requirements can be changed, such as changing the fracture width, etc., to change the ideal fracture distribution pattern to a sub-ideal distribution pattern, etc. The sub-ideal distribution pattern is close to the ideal fracture distribution pattern.

[0133] Among them, the process of calculating the three-dimensional stress interference range and degree by the stress interference calculation model is: combining the results of seismic data interpretation and indoor core experiment data to conduct macroscopic and microscopic nested characterization of reservoir heterogeneity, and then using the damage mechanics and fluid-solid coupling fracture propagation model to calculate the stress interference range and degree of fractures under different conditions.

[0134] The above-mentioned stress interference calculation model adopts an improved stress interference characterization method, that is, the "macro-microscopic nested" method is used to characterize reservoir heterogeneity, and the damage mechanics principle is combined to calculate multi-dimensional induced stress, thereby improving the calculation accuracy of the stress interference range and degree of fractures on the in-situ stress field.

[0135] Exemplarily, in one embodiment, the macroscopic and mesoscopic nested characterization of reservoir heterogeneity is carried out by combining the interpretation results of seismic data and the indoor core experiment data, and then the stress interference range and degree of fractures under different conditions are calculated by using the damage mechanics and fluid-solid coupling fracture propagation model. The specific implementation process is as follows:

[0136] S01. Geological modeling is carried out based on seismic geophysical exploration data, which belongs to macroscopic modeling and is the first assignment of the grid. For example, the data modeling accuracy is selected as 5m.

[0137] S02. The discontinuous surfaces are characterized by weakening the rock mechanical properties. The discontinuous surfaces include faults and natural fractures, etc.

[0138] S03. Determine the values of the Weibull function based on the logging interpretation results and indoor core experiment data, which belongs to mesoscopic modeling. For example, the data modeling accuracy is selected at the cm to m level.

[0139] S04. Based on the determined Weibull function, each grid of the geological modeling is individually assigned a second value to complete the macroscopic and mesoscopic nested modeling.

[0140] S05. Use the damage mechanics and fluid-solid coupling fracture propagation model to calculate the stress interference range and degree of fractures under different conditions.

[0141] Exemplarily, in one embodiment, the specific implementation process of S100 is as follows:

[0142] S101. Without considering the artificial stress interference condition, simulate the hydraulic fracture morphology based on the original in-situ stress field. Preferably, after simulating the hydraulic fracture morphology based on the original in-situ stress field, the obtained simulated hydraulic fracture morphology can be corrected through on-site micro-injection testing to improve the accuracy of the simulation results.

[0143] S102. Determine the required fracture demand distribution morphology that meets the second preset condition by combining the reservoir structure characteristics and sedimentary characteristics of the reformed area. The second preset condition includes no cross-fracturing and maximizing the utilization of formations. Preferably, the reservoir structure characteristics may include the strike and dip changes, faults, distribution morphology and scale of natural fractures, etc., and the reservoir sedimentary characteristics may include lithology, bedding and thickness, etc.

[0144] S103. Calculate the stress field conditions required to form the fracture demand distribution morphology. The stress field conditions include the stress magnitude and direction, and this stress field is the designed stress field.

[0145] In addition, the simulated hydraulic fracture morphology and the fracture demand distribution morphology include fracture height, fracture length and propagation path, etc. No cross-fracturing means no cross-fracturing between layers caused by out-of-control fracture height, and no cross-fracturing between wells caused by unreasonable fracture length and propagation path, etc.

[0146] For those of ordinary skill in the art, it should be understood that: in S101, when calculating and simulating the hydraulic fracture morphology through the original in-situ stress field, the simulation process in the general embodiment can be adopted. For example, the calculation can be carried out based on the publicly available hydraulic fracture morphology simulation module, and this embodiment will not describe this process in detail; in S102, when determining the required fracture distribution morphology that meets the second preset condition in combination with the reservoir structure characteristics and sedimentary characteristics of the reformed area, it can be initially judged based on well-known experience on the basis of a fine geological model.

[0147] Exemplarily, in one embodiment, the specific implementation process of S103 is: after comparing the differences between the simulated hydraulic fracture morphology and the required fracture distribution morphology, the stress field required to form the required fracture distribution morphology is calculated using the damage mechanics and fluid-solid coupling fracture propagation model.

[0148] The establishment and application environment of the high-stress barrier include multiple wells in the same layer and multiple wells in multiple layers. The application conditions for multiple wells in the same layer are: due to mining reasons, there is a low-stress area (the "parent-child effect" area) in the adjacent well. The application conditions for multiple wells in multiple layers are: when there is no high-stress interlayer between the upper and lower reservoirs, or natural fractures are developed, or the well spacing between the upper and lower wells is relatively small, there is a possibility of hydraulic fracture connection between the upper and lower wells. For example, for well A above and well B below, there is a possibility of connection between the hydraulic fracture A-i of well A and the hydraulic fracture B-j of well B.

[0149] In one embodiment, when the area where the high-stress barrier needs to be manufactured is under the application conditions of multiple wells in the same layer, the specific process of designing the manufacturing parameters of the high-stress barrier for this area is as follows:

[0150] SS01. Obtain the stress field difference after comparing the in-situ stress of the adjacent well with that of the reformed area of the target well;

[0151] SS02. Combine the stress interference calculation model for multi-dimensional induced stress that has been constructed, calculate the required multi-fracture three-dimensional stress interference range and degree according to the above stress field difference and the hydraulic fracture morphology of the adjacent well, and determine the liquid viscosity and usage amount required to generate this three-dimensional stress interference range and degree, so as to install a packer at the wellbore position corresponding to the adjacent low-stress area, and then pump the liquid according to the liquid viscosity and usage amount and shut in the well, thereby completing the manufacturing of the high-stress barrier in this area. Preferably, for example, install a packer at a depth of 5 m at the wellbore position corresponding to the adjacent low-stress area, and pump a temporary plugging agent or other materials while pumping the liquid to establish the high-stress barrier.

[0152] In one embodiment, when the area where the high-stress barrier needs to be manufactured is under the application conditions of multiple wells in multiple layers, the specific process of designing the manufacturing parameters of the high-stress barrier for this area is as follows:

[0153] SSS01. Calculate the maximum safe fracture height of the upper well hydraulic fracture and the lower well hydraulic fracture that may be connected, or the maximum safe fracture height at which the hydraulic fracture does not extend to the lower layer or the upper layer, according to the interlayer distance or the spacing between the upper well and the lower well. For example, if there is a possibility of connection between the A-i fracture of the upper well A and the B-j fracture of the lower well B, the maximum safe fracture height of the A-i fracture is denoted as A1, and the maximum safe fracture height of the B-j fracture is denoted as B1.

[0154] SSS02. Calculate the fracture height of the upper well hydraulic fracture and the lower well hydraulic fracture, or the fracture height at which the hydraulic fracture does not extend to the lower layer or the upper layer, without the condition of artificial stress interference, and based on the difference between each fracture height and the corresponding maximum safe fracture height, calculate the required stress interference range and degree based on the stress interference calculation model constructed for multi-dimensional induced stress calculation. For example, without the condition of artificial stress interference, the fracture height of the A-i fracture of the upper well A is denoted as a1, and the fracture height of the B-j fracture of the lower well B is denoted as b1. The said differences are respectively: A1 - a1 and B1 - b1.

[0155] SSS03. Determine the fracturing parameters according to the calculated stress interference range and degree, so as to use the fracturing parameters for the fracturing construction in this area, thereby completing the manufacture of the high-stress barrier in this area. The fracturing parameters include fracturing pump injection parameters, etc.

[0156] Exemplarily, in one embodiment, the specific implementation process of step S200 is as follows:

[0157] S201. In the designed stress field and the original in-situ stress field, within a range of 200 m from the wellbore, compare the three parameters of each grid in each geological model. If the relative errors of the three parameters are all between -20% and 20%, it is determined that there is no area where a high-stress barrier needs to be manufactured at this time, and S400 is executed; otherwise, it is determined that there is an area where a high-stress barrier needs to be manufactured at this time, and S300 is executed. Among them, the three parameters are the maximum horizontal principal stress σ max , the minimum horizontal principal stress σ min and the horizontal stress difference ratio σ max / σ min .

[0158] Exemplarily, in one embodiment, the specific implementation process of step S400 is as follows:

[0159] S401. Determine the current fracturing parameters according to the actual requirements of each fracture in the required fracture distribution pattern.

[0160] S402. Combine the current fracturing parameters, and based on the stress interference calculation model constructed for multi-dimensional induced stress calculation, calculate the actual stress field generated after the formation of all fractures in the required fracture distribution pattern. If there is a region where a high-stress barrier needs to be created, add the stress interference generated after the creation of the high-stress barrier in this region to the above-mentioned actual stress field.

[0161] S403. Determine whether the difference between the actual stress field and the designed stress field is within the first preset range. If so, proceed to the next step; otherwise, determine that a high-stress barrier needs to be created and jump to S300. When the cumulative number of jumps reaches the first threshold, jump to S100. Preferably, the first preset range is 0 - 20%, for example, taking the upper limit of 20%. Here, the cumulative number of jumps reaching the first threshold means that when the difference between the actual stress field and the designed stress field exceeds the first preset range, it indicates that a high-stress barrier needs to be created to make the difference between the actual stress field and the designed stress field meet the first preset range. Therefore, jump to S300. However, after multiple jumps and repeated execution of S300, the above difference is still not within the first preset range. At this time, the fracture requirement should be reduced, that is, jump to S100. In this implementation step, the calculation method of the difference between the actual stress field and the designed stress field can refer to S201, that is, based on the three-parameter comparison of each grid in the geological model.

[0162] S404. Determine whether the degree of conformity between the actual fracture pattern and the required fracture distribution pattern is within the second preset range. If so, proceed to the next step; otherwise, jump to S100. Preferably, the second preset range is 80% - 100%, for example, taking the lower limit of 80%. Here, jumping to S100 means that when the degree of conformity between the actual fracture pattern and the required fracture distribution pattern does not meet the second preset range, at this time, the fracture requirement should be reduced, that is, jump to S100.

[0163] S405. Determine whether there is fracturing channeling. If so, jump to S100; otherwise, use the latest fracturing parameters as the parameters for fracturing construction in the reformed area of the target well. When there is a region where a high-stress barrier needs to be created, also use the latest high-stress barrier creation parameters as the parameters for fracturing construction in the reformed area of the target well. Here, jumping to S100 means that at this time, there is fracturing channeling, indicating that the fracture requirement should be reduced, that is, jump to S100.

[0164] In one embodiment, a specific implementation process of S401 can be:

[0165] S4011. Calculate the actual requirements of each fracture in the required fracture distribution pattern according to the rock mechanical properties and the stress distribution pattern of the drilled box body. The actual requirements of the fracture include the fracture initiation position, geometric parameters, and extension path.

[0166] S4012. Determine the required current fracturing parameters based on the actual requirements of the fractures.

[0167] System embodiment

[0168] The present invention provides a three-dimensional fracturing design system, which includes a first comparison module. The first comparison module is connected to a first determination module, a first design module, and a second determination module. The second determination module is also respectively connected to the first determination module and the first design module.

[0169] The first determination module is used to execute the first determination step; the first determination step includes: determining the stress field required for the target well reconstruction area to reach the fracture demand distribution state, and this stress field is the design stress field.

[0170] The first comparison module is used to determine whether there is an area that needs to create a high-stress barrier after comparing the differences between the design stress field and the original in-situ stress field. If so, enter the first design step; otherwise, enter the second determination step.

[0171] The first design module is used to execute the first design step. The first design step includes: designing the manufacturing parameters of the high-stress barrier for the area that needs to create a high-stress barrier.

[0172] The second determination module is used to execute the second determination step.

[0173] The second determination step includes: combining the design parameters and using the stress interference calculation model constructed for multi-dimensional induced stress calculation to calculate the stress interference range and degree of multiple fractures. If the first preset condition is met, use this design parameter as the parameter for fracturing construction in the target well reconstruction area; otherwise, under the premise of changing the design parameters and / or reducing the fracture demand, repeat using the stress interference calculation model to calculate the stress interference range and degree of multiple fractures until the first preset condition is met, and use the latest design parameter as the parameter for fracturing construction in the target well reconstruction area. Among them, the first preset condition is: the difference between the actual stress field after fracture interference and the design stress field is within the first preset range, and the conformity between the actual fracture morphology within the calculation range and the fracture demand distribution morphology is within the second preset range, and there is no fracturing breakthrough. The design parameters include fracturing parameters, and when there is an area that needs to create a high-stress barrier, they also include high-stress barrier manufacturing parameters. The fracturing parameters are determined based on the actual requirements of each fracture in the fracture demand distribution morphology.

[0174] Optionally, the process of calculating the three-dimensional stress interference range and degree by the stress interference calculation model is as follows:

[0175] Combining the results of seismic data interpretation and indoor core experiment data to conduct macroscopic and microscopic nested characterization of reservoir heterogeneity;

[0176] Calculate the stress interference range and degree of fractures under different conditions by using damage mechanics and fluid-solid coupling fracture propagation models.

[0177] Optionally, the specific process of the first determination module for determining the stress field required for the fracture demand distribution state to be reached in the target well reconstruction area is as follows:

[0178] Calculate and simulate the hydraulic fracture morphology based on the original in-situ stress field;

[0179] Determine the fracture demand distribution morphology that meets the second preset condition in combination with the reservoir characteristics of the reconstruction area. The second preset condition includes no fracturing communication and maximizing the utilization of formations;

[0180] Calculate the stress field required to form the fracture demand distribution morphology, and this stress field is the designed stress field.

[0181] Optionally, the second determination module includes a first calculation module, a second calculation module, a first judgment module, a second judgment module, and a third judgment module connected in sequence. The first judgment module is also connected to the first design module and the first determination module, and the second judgment module and the third judgment module are also respectively connected to the first determination module.

[0182] The first calculation module is used to execute the first calculation step; the first calculation step includes: determining the current fracturing parameters according to the actual requirements of each fracture in the fracture demand distribution morphology.

[0183] The second calculation module is used to execute the actual stress field calculation step. The actual stress field calculation step includes: combining the current fracturing parameters and calculating the actual stress field generated after all fractures in the fracture demand distribution morphology are formed based on the stress interference calculation model constructed for multi-dimensional induced stress calculation. If there is an area where a high-stress barrier needs to be created, the stress interference generated after the creation of the high-stress barrier in this area is added to this actual stress field.

[0184] The first judgment module is used to judge whether the difference between the actual stress field and the designed stress field is within the first preset range. If so, enter the second judgment step; otherwise, determine that a high-stress barrier needs to be created and jump to the first design step. When the cumulative number of jumps reaches the first threshold, then jump to the first determination step.

[0185] The second judgment module is used to execute the second judgment step. The second judgment step includes: judging whether the compliance between the actual fracture morphology and the fracture demand distribution morphology is within the second preset range. If so, enter the third judgment step; otherwise, enter the first determination step.

[0186] The third judgment module is used to execute the third judgment step. The third judgment step includes: judging whether there is crossflow. If so, enter the first determination step. Otherwise, use the latest fracturing parameters as the parameters for fracturing construction in the target well's transformation area. When there is an area where a high-stress barrier needs to be created, also use the latest high-stress barrier creation parameters as the parameters for fracturing construction in the target well's transformation area.

[0187] Optionally, the macroscopic and microscopic nested characterization of reservoir heterogeneity is carried out by combining seismic data interpretation results and indoor core experiment data. The specific process is as follows:

[0188] Based on seismic geophysical data, geological modeling is carried out, that is, the first assignment of the grid;

[0189] The discontinuous surfaces are characterized by weakening the rock mechanical properties. The discontinuous surfaces include faults and natural fractures;

[0190] Based on well logging interpretation results and indoor core experiment data, each value of the Weibull function is determined;

[0191] Based on the determined Weibull function, each grid of the geological modeling is individually assigned a second value to complete the macroscopic and microscopic nested modeling.

[0192] Optionally, when the area where a high-stress barrier needs to be created is in an environment of multiple wells in the same layer and there is a low-stress area in the adjacent well, the specific process for designing the high-stress barrier creation parameters for this area is as follows:

[0193] After comparing the in-situ stress of the adjacent well with that of the target well's transformation area, the stress field difference is obtained;

[0194] Combined with the stress interference calculation model already constructed for multi-dimensional induced stress calculation, according to the stress field difference and the hydraulic fracture morphology of the adjacent well, calculate the required multi-fracture stress interference range and degree, and determine the liquid viscosity and usage amount required to generate this stress interference range and degree, so as to facilitate the setting of a packer at the wellbore position corresponding to the low-stress area, and then pump the liquid according to the liquid viscosity and usage amount and shut in the well, thereby completing the creation of the high-stress barrier in this area.

[0195] Optionally, when the area where a high-stress barrier needs to be created is in an environment of multiple wells in multiple layers and there is no high-stress interlayer between the upper and lower reservoirs, or natural fractures are developed, or the well spacing between the upper and lower wells is small, resulting in the possibility of hydraulic fracture connection between the upper and lower wells, the specific process for designing the high-stress barrier creation parameters for this area is as follows:

[0196] According to the interlayer distance, or the distance between the upper well and the lower well, calculate the maximum safe fracture height of the hydraulic fractures of the upper well and the lower well that may be connected, or the maximum safe fracture height at which the hydraulic fractures do not extend to the lower layer or the upper layer;

[0197] Calculate the height of the upper well hydraulic fracture and the lower well hydraulic fracture without artificial stress interference, or the height of the hydraulic fracture that does not extend to the lower or upper layer, and based on the difference between each fracture height and the corresponding maximum safe fracture height, calculate the required stress interference range and degree using the stress interference calculation model constructed for multi-dimensional induced stress calculation;

[0198] Determine the fracturing parameters based on the calculated stress interference range and degree, so as to use these fracturing parameters for the fracturing construction in this area, thereby completing the manufacturing of the high-stress barrier in this area.

[0199] Optionally, after the first comparison module compares the differences between the designed stress field and the original in-situ stress field to determine whether there is an area where a high-stress barrier needs to be manufactured. If so, enter the first design step; otherwise, enter the second determination step, which specifically includes:

[0200] In the designed stress field and the original in-situ stress field, within a range of 200 m from the wellbore, compare the three parameters of each grid in each geological model. If the relative errors of the three parameters are all between -20% and 20%, it is determined that there is no area where a high-stress barrier needs to be manufactured at this time, and enter the second determination step; otherwise, it is determined that there is an area where a high-stress barrier needs to be manufactured at this time, and enter the first design step. The three parameters are the maximum horizontal principal stress σ max 、the minimum horizontal principal stress σ min and the horizontal stress difference ratio σ max / σ min .

[0201] Optionally, both the simulated hydraulic fracture morphology and the required fracture distribution morphology include fracture height, fracture length, and extension path.

[0202] Optionally, calculate the stress field required to form the required fracture distribution morphology, including:

[0203] After comparing the differences between the simulated hydraulic fracture morphology and the required fracture distribution morphology, calculate the stress field required to form the required fracture distribution morphology using damage mechanics and fluid-solid coupling fracture propagation models.

[0204] Optionally, determine the current fracturing parameters based on the actual requirements of each fracture in the required fracture distribution morphology, including:

[0205] Calculate the actual requirements of each fracture in the required fracture distribution morphology according to the rock mechanical properties and the stress distribution morphology of the drilled box. The actual requirements include the fracture initiation position, geometric parameters, and extension path;

[0206] Based on the actual requirements of the fractures, determine the required current fracturing parameters. The fracturing parameters include perforation parameters and fracturing pump injection parameters. The perforation parameters include perforation position, perforation density, and hole size.

[0207] Optionally, the first preset range is 0 to 20%.

[0208] Optionally, the second preset range is 80% to 100%.

[0209] Optionally, after calculating and simulating the hydraulic fracture morphology based on the original in-situ stress field, the results are corrected through on-site micro-injection tests.

[0210] It can be known that the system embodiments described above are only illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art can understand and implement it without creative labor.

[0211] On the other hand, the present invention also provides a processor for running a program, and when the program runs, it executes the three-dimensional fracturing design method described in the above method embodiment.

[0212] On another aspect, the present invention also provides a device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, it implements the three-dimensional fracturing design method described in the above method embodiment.

[0213] On another aspect, the present invention also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements the three-dimensional fracturing design method described in the method embodiment.

[0214] On another aspect, the present invention also provides a computer program product, which includes a computer program. The computer program can be stored on a machine-readable storage medium. When the computer program is executed by a processor, it can implement the three-dimensional fracturing design method described in the method embodiment of the present invention.

[0215] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on such an understanding, the above technical solutions, in essence, or the part that contributes to the prior art can be embodied in the form of a software product. The computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disc, etc., and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0216] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. And these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A three-dimensional fracturing design method, characterized in that, Including: S100. Determine the stress field required for the target well reconstruction area to reach the crack demand distribution state, and this stress field is the design stress field; S200. After comparing the differences between the design stress field and the original in-situ stress field, determine whether there is an area where a high-stress barrier needs to be created. If so, execute S300; otherwise, execute S400; S300. Design the manufacturing parameters of the high-stress barrier for the area where the high-stress barrier needs to be created; S400. Combine the design parameters and use the stress interference calculation model for multi-dimensional induced stress calculation that has been constructed to calculate the stress interference range and degree of multiple cracks. If the first preset condition is met, use this design parameter as the parameter for fracturing construction in the target well reconstruction area. Otherwise, under the premise of changing the design parameter and / or reducing the crack demand, repeatedly use the stress interference calculation model to calculate the stress interference range and degree of multiple cracks until the first preset condition is met, and use the latest design parameter as the parameter for fracturing construction in the target well reconstruction area; The first preset condition is: the difference between the actual stress field after crack interference and the design stress field is within the first preset range, and the compliance between the actual crack morphology within the calculation range and the crack demand distribution morphology is within the second preset range, and there is no fracturing breakthrough; The design parameters include fracturing parameters. When there is an area where a high-stress barrier needs to be created, they also include the manufacturing parameters of the high-stress barrier; The fracturing parameters are determined based on the actual requirements of each crack in the crack demand distribution morphology.

2. The three-dimensional fracturing design method according to claim 1, wherein The process of the stress interference calculation model calculating the stress interference range and degree is as follows: Combine the results of seismic data interpretation and indoor core experiment data to conduct macroscopic and microscopic nested characterization of reservoir heterogeneity; Use the damage mechanics and fluid-solid coupling crack propagation model to calculate the stress interference range and degree of cracks under different conditions.

3. The method for three-dimensional fracturing design according to claim 1, characterized in that In step S100, determining the stress field required for the target well reconstruction area to reach the crack demand distribution state, and this stress field is the design stress field, includes: S101. Calculate and simulate the hydraulic crack morphology based on the original in-situ stress field; S102. Combine the reservoir structure characteristics and sedimentary characteristics of the reconstruction area to determine the crack demand distribution morphology that meets the second preset conditions. The second preset conditions include no fracturing breakthrough and maximizing the utilization of formations; S103. Calculate the stress field required to form the crack demand distribution morphology, and this stress field is the design stress field.

4. A three-dimensional fracturing design method according to claim 1, characterized in that Step S400 includes: S401. Determine the current fracturing parameters based on the actual requirements of each crack in the crack demand distribution morphology; S402. Combine the current fracturing parameters and, based on the stress interference calculation model for multi-dimensional induced stress calculation that has been constructed, calculate the actual stress field generated after all cracks in the crack demand distribution morphology are formed. If there is an area where a high-stress barrier needs to be created, add the stress interference generated after the creation of the high-stress barrier in this area to the actual stress field; S403. Judge whether the difference between the actual stress field and the design stress field is within the first preset range. If so, execute the next step; otherwise, determine that a high-stress barrier needs to be created and jump to S300. When the cumulative number of jumps reaches the first threshold, jump to S100; S404. Determine whether the compliance degree between the actual fracture morphology and the required fracture distribution morphology is within the second preset range. If so, proceed to the next step; otherwise, jump to S100. S405. Determine whether there is fracturing and channeling. If so, jump to S100; otherwise, use the latest fracturing parameters as the parameters for fracturing the target well's transformation area. When there is an area that requires creating a high-stress barrier, also use the latest high-stress barrier creation parameters as the parameters for fracturing the target well's transformation area.

5. A three-dimensional fracturing design method according to claim 2, characterized in that, Nested characterization of reservoir heterogeneity at the macroscopic and microscopic levels is carried out by combining the results of seismic data interpretation and indoor core experiment data. The specific process is as follows: Based on seismic geophysical data, geological modeling is performed, that is, the first assignment of the grid. The discontinuous surfaces, including faults and natural fractures, are characterized by weakening the rock mechanical properties. Based on the logging interpretation results and indoor core experiment data, determine the values of each parameter of the Weibull function. Based on the determined Weibull function, perform a secondary assignment for each grid of the geological modeling separately to complete the nested modeling at the macroscopic and microscopic levels.

6. The three-dimensional fracturing design method according to claim 1, wherein In S300, when the area that requires creating a high-stress barrier is in an environment where there are multiple wells in the same layer and there is a low-stress area in the adjacent well, the specific process for designing the high-stress barrier creation parameters for this area is as follows: Obtain the stress field difference by comparing the in-situ stress of the adjacent well with that of the target well's transformation area. Combined with the stress interference calculation model for multi-dimensional induced stress that has been constructed, calculate the required multi-fracture stress interference range and degree according to the stress field difference and the hydraulic fracture morphology of the adjacent well, and determine the liquid viscosity and usage amount required to generate this stress interference range and degree, so as to facilitate lowering a packer at the wellbore position corresponding to the low-stress area, then pumping the liquid according to the liquid viscosity and usage amount and shutting in the well, thereby completing the creation of the high-stress barrier in this area.

7. A three-dimensional fracturing design method according to claim 1, characterized in that In S300, when the area that requires creating a high-stress barrier is in an environment where there are multiple wells in multiple layers and there is no high-stress interlayer between the upper and lower reservoirs, or natural fractures are developed, or the well spacing between the upper and lower wells is small, resulting in the possibility of hydraulic fracture connection between the upper and lower wells, the specific process for designing the high-stress barrier creation parameters for this area is as follows: According to the interlayer distance, or the distance between the upper well and the lower well, calculate the maximum safe fracture height of the hydraulic fractures of the upper well and the lower well that may be connected, or the maximum safe fracture height when the hydraulic fractures do not extend to the lower layer or the upper layer. Calculate the fracture height of the hydraulic fractures of the upper well and the lower well, or the fracture height when the hydraulic fractures do not extend to the lower layer or the upper layer, without using artificial stress interference, and based on the difference between each fracture height and the corresponding maximum safe fracture height, calculate the required stress interference range and degree based on the stress interference calculation model for multi-dimensional induced stress that has been constructed. Determine the fracturing parameters according to the calculated stress interference range and degree, so as to facilitate using these fracturing parameters for fracturing construction in this area, thereby completing the creation of the high-stress barrier in this area.

8. The three-dimensional fracturing design method according to claim 1, wherein Step S200 includes: In the designed stress field and the original in-situ stress field, within a range of 200 m from the wellbore, compare the three parameters of each grid in each geological model. If the relative errors of the three parameters are all between -20% and 20%, it is determined that there is no area where a high-stress barrier needs to be created at this time, and S400 is executed; otherwise, it is determined that there is an area where a high-stress barrier needs to be created at this time, and S300 is executed. The three parameters are the maximum horizontal principal stress σ max , the minimum horizontal principal stress σ min and the horizontal stress difference ratio σ max / σ min .

9. The method for three-dimensional fracturing design according to claim 3, characterized in that Both the simulated hydraulic fracture morphology and the required fracture distribution morphology include fracture height, fracture length, and extension path.

10. A method for three-dimensional fracturing design according to claim 3, characterized in that, In S103, calculating the stress field required to form the required fracture distribution morphology includes: After comparing the differences between the simulated hydraulic fracture morphology and the required fracture distribution morphology, use the damage mechanics and fluid-solid coupling fracture propagation model to calculate the stress field required to form the required fracture distribution morphology.

11. A three-dimensional fracturing design method according to claim 4, characterized in that, In S401, determining the current fracturing parameters based on the actual requirements of each fracture in the required fracture distribution morphology includes: S4011. Calculate the actual requirements of each fracture in the required fracture distribution morphology according to the rock mechanical properties and the stress distribution morphology of the drilled box. The actual requirements include the fracture initiation position, geometric parameters, and extension path. S4012. Based on the actual requirements of the fracture, determine the required current fracturing parameters. The fracturing parameters include perforation parameters and fracturing pumping parameters. The perforation parameters include perforation position, perforation density, and hole size.

12. A three-dimensional fracturing design method according to claim 1, characterized in that, The first preset range is 0 - 20%.

13. The three-dimensional fracturing design method according to claim 1, wherein The second preset range is 80% - 100%.

14. A three-dimensional fracturing design method according to claim 3, characterized in that, In S101, after calculating the simulated hydraulic fracture morphology based on the original in-situ stress field, the results are corrected through on-site micro-injection testing.

15. A three-dimensional fracturing design system, characterized in that, It includes a first comparison module, which is connected to a first determination module, a first design module, and a second determination module. The second determination module is also respectively connected to the first determination module and the first design module. The first determination module is used to execute the first determination step. The first determination step includes: determining the stress field required for the target well reconstruction area to reach the required fracture distribution state. This stress field is the designed stress field. The first comparison module is used to determine whether there is an area where a high-stress barrier needs to be created after comparing the differences between the designed stress field and the original in-situ stress field. If so, enter the first design step; otherwise, enter the second determination step. The first design module is used to execute the first design step. The first design step includes: designing the manufacturing parameters of the high-stress barrier for the area where the high-stress barrier needs to be created. The second determination module is used to execute the second determination step. The second determination step includes: Combined with the design parameters, use the stress interference calculation model for multi-fracture stress calculation that has been constructed to calculate the stress interference range and degree of multi-fractures. If the first preset condition is met, use this design parameter as the parameter for fracturing construction in the target well reconstruction area; otherwise, under the premise of changing the design parameter and / or reducing the fracture requirement, repeat using the stress interference calculation model to calculate the stress interference range and degree of multi-fractures until the first preset condition is met, and use the latest design parameter as the parameter for fracturing construction in the target well reconstruction area. The first preset condition is that the difference between the actual stress field and the designed stress field after the crack interference occurs is within the first preset range, and the compliance between the actual crack pattern within the calculation range and the required crack distribution pattern is within the second preset range, and there is no pressure channeling; The design parameters include fracturing parameters, and when there is an area where a high-stress barrier needs to be created, they also include high-stress barrier creation parameters; The fracturing parameters are determined based on the actual requirements of each crack in the required crack distribution pattern.

16. A three-dimensional fracturing design system according to claim 15, characterized in that, The process of the stress interference calculation model calculating the stress interference range and degree is as follows: Combining the results of seismic data interpretation and indoor core experiment data to conduct macroscopic and microscopic nested characterization of reservoir heterogeneity; Using the damage mechanics and fluid-solid coupling crack propagation model to calculate the stress interference range and degree of cracks under different conditions.

17. A three-dimensional fracturing design system according to claim 15, characterized in that, The specific process of the first determination module determining the stress field required for the target well reconstruction area to reach the required crack distribution state is as follows: Calculating and simulating the hydraulic crack pattern based on the original in-situ stress field; Combining the reservoir characteristics of the reconstruction area to determine the required crack distribution pattern that meets the second preset condition, and the second preset condition includes no pressure channeling and maximizing the utilization of formations; Calculating the stress field required to form the required crack distribution pattern, and this stress field is the designed stress field.

18. A three-dimensional fracturing design system according to claim 15, characterized in that, The second determination module includes a first calculation module, a second calculation module, a first judgment module, a second judgment module, and a third judgment module connected in sequence. The first judgment module is also connected to the first design module and the first determination module, and the second judgment module and the third judgment module are also respectively connected to the first determination module; The first calculation module is used to execute the first calculation step; The first calculation step includes: determining the current fracturing parameters based on the actual requirements of each crack in the required crack distribution pattern; The second calculation module is used to execute the actual stress field calculation step; The actual stress field calculation step includes: combining the current fracturing parameters and, based on the constructed stress interference calculation model for multi-dimensional induced stress calculation, calculating the actual stress field generated after all cracks in the required crack distribution pattern are formed. If there is an area where a high-stress barrier needs to be created, the stress interference generated after the creation of the high-stress barrier in this area is added to the actual stress field; The first judgment module is used to judge whether the difference between the actual stress field and the designed stress field is within the first preset range. If so, it enters the second judgment step. Otherwise, it is determined that a high-stress barrier needs to be created and jumps to the first design step. When the cumulative number of jumps reaches the first threshold, it jumps to the first determination step; The second judgment module is used to execute the second judgment step; The second judgment step includes: Judging whether the compliance between the actual crack pattern and the required crack distribution pattern is within the second preset range. If so, it enters the third judgment step. Otherwise, it enters the first determination step; The third judgment module is used to execute the third judgment step; The third judgment step includes: Determine whether there is cross - formation flow. If so, enter the first determination step; otherwise, use the latest fracturing parameters as the parameters for fracturing the target well's reformed area. When there is an area that needs to create a high - stress barrier, also use the latest high - stress barrier creation parameters as the parameters for fracturing the target well's reformed area.

19. A three-dimensional fracturing design system according to claim 16, characterized in that, Combined with the seismic data interpretation results and laboratory core experiment data, conduct macroscopic and microscopic nested characterization of reservoir heterogeneity. The specific process is as follows: Based on seismic geophysical data, conduct geological modeling, that is, the first assignment of the grid; Use the weakening characterization of rock mechanical properties to represent discontinuity surfaces, and the discontinuity surfaces include faults and natural fractures; Based on the well - logging interpretation results and laboratory core experiment data, determine the values of each parameter of the Weibull function; Based on the determined Weibull function, conduct a secondary assignment for each grid of the geological modeling separately to complete the macroscopic and microscopic nested modeling.

20. A three-dimensional fracturing design system according to claim 15, characterized in that When the area that needs to create a high - stress barrier is in an environment where there are multiple wells in the same layer and there is a low - stress area in the adjacent well, the specific process for designing the high - stress barrier creation parameters for this area is as follows: Obtain the stress field difference after comparing the in - situ stress of the adjacent well with that of the target well's reformed area; Combined with the stress interference calculation model for multi - dimensional induced stress that has been constructed, calculate the required multi - fracture stress interference range and degree according to the stress field difference and the hydraulic fracture morphology of the adjacent well, and determine the liquid viscosity and usage amount required to generate this stress interference range and degree, so as to facilitate setting a packer at the wellbore position corresponding to the low - stress area. Then, pump the liquid according to the liquid viscosity and usage amount and shut in the well to complete the creation of the high - stress barrier in this area.

21. A three-dimensional fracturing design system according to claim 15, characterized in that, When the area that needs to create a high - stress barrier is in an environment where there are multiple wells in multiple layers and there is no high - stress interlayer between the upper and lower reservoirs, or natural fractures are developed, or the well spacing between the upper and lower wells is small, resulting in the possibility of hydraulic fracture connection between the upper and lower wells, the specific process for designing the high - stress barrier creation parameters for this area is as follows: According to the interlayer distance or the distance between the upper well and the lower well, calculate the maximum safe fracture height of the hydraulic fractures in the upper well and the lower well that may be connected, or the maximum safe fracture height of the hydraulic fractures that do not extend to the lower layer or the upper layer; Calculate the fracture height of the hydraulic fractures in the upper well and the lower well, or the fracture height of the hydraulic fractures that do not extend to the lower layer or the upper layer without artificial stress interference, and based on the difference between each fracture height and the corresponding maximum safe fracture height, calculate the required stress interference range and degree based on the stress interference calculation model for multi - dimensional induced stress that has been constructed; Determine the fracturing parameters according to the calculated stress interference range and degree, so as to use these fracturing parameters for fracturing construction in this area to complete the creation of the high - stress barrier in this area.

22. A three-dimensional fracturing design system according to claim 15, characterized in that, The first comparison module determines whether there is an area that needs to create a high - stress barrier after comparing the differences between the designed stress field and the original in - situ stress field. If so, enter the first design step; otherwise, enter the second determination step, specifically including: In the designed stress field and the original in-situ stress field, within a range of 200 m from the wellbore, compare the three parameters of each grid in each geological model. If the relative errors of the three parameters are all between -20% and 20%, it is determined that there is no area where a high-stress barrier needs to be created at this time, and the second determination step is entered; otherwise, it is determined that there is an area where a high-stress barrier needs to be created at this time, and the first design step is entered. The three parameters are the maximum horizontal principal stress σ max , the minimum horizontal principal stress σ min , and the horizontal stress difference ratio σ max / σ min .

23. A three-dimensional fracturing design system according to claim 17, characterized in that, Both the simulated hydraulic fracture morphology and the required fracture distribution morphology include fracture height, fracture length, and propagation path.

24. A three-dimensional fracturing design system according to claim 17, wherein Calculating the stress field required to form the required fracture distribution morphology includes: After comparing the differences between the simulated hydraulic fracture morphology and the required fracture distribution morphology, use damage mechanics and fluid-solid coupling fracture propagation models to calculate the stress field required to form the required fracture distribution morphology.

25. A three-dimensional fracturing design system according to claim 18, characterized in that, Determining the current fracturing parameters based on the actual requirements of each fracture in the required fracture distribution morphology includes: Calculate the actual requirements of each fracture in the required fracture distribution morphology according to the rock mechanical properties and the stress distribution morphology of the drilled box. The actual requirements include the fracture initiation position, geometric parameters, and propagation path. Based on the actual requirements of the fractures, determine the required current fracturing parameters. The fracturing parameters include perforation parameters and fracturing pumping parameters. The perforation parameters include perforation position, perforation density, and hole size.

26. A three-dimensional fracturing design system according to claim 15, characterized in that, The first preset range is 0 to 20%.

27. A three-dimensional fracturing design system according to claim 15, characterized in that, The second preset range is 80% to 100%.

28. A three-dimensional fracturing design system according to claim 17, characterized in that, After calculating the simulated hydraulic fracture morphology based on the original in-situ stress field, the results are corrected through on-site micro-injection tests.

29. An apparatus, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein When the processor executes the program, it implements the three-dimensional fracturing design method according to any one of claims 1 to 14.

30. A processor, characterized in that, The processor is used to run a program, where when the program runs, it executes the three-dimensional fracturing design method according to any one of claims 1 to 14.

31. A storage medium, on which a computer program is stored, characterized in that, When the computer program is executed by the processor, it implements the three-dimensional fracturing design method according to any one of claims 1 to 14.

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