Evaluation method for obtaining contribution of shale oil artificial fracture and stratum energy to recovery efficiency

Abstract

The invention belongs to the technical field of oil and gas exploitation, and relates to an evaluation method for obtaining contribution of shale oil artificial fracture and stratum energy to recovery efficiency. According to the method, artificial fractures are loaded in the process of constructing a three-dimensional fine reservoir geologic model containing natural fractures, artificial fracture flow conductivity assignment is carried out, a matrix-fracture model is obtained, and the first single well yield is obtained according to the matrix-fracture model; performing fracturing fluid elastic energy assignment on the matrix-fracture model to obtain a second single well yield; assigning the elastic energy of the reservoir fluid to the matrix-fracture model assigned with the elastic energy of the fracturing fluid to obtain a third single well yield; performing assignment of reservoir rock elastic energy on the matrix-fracture model after assignment of reservoir fluid elastic energy to obtain a fourth single well yield; and finally, the first single well yield, the second single well yield, the third single well yield and the fourth single well yield at different production times are obtained, and the contribution of the artificial fracture and stratum energy to the shale oil yield and the final recovery efficiency is obtained.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas extraction technology, and relates to an evaluation method for obtaining the contribution of artificial fractures and formation energy to the recovery rate of shale oil. Background Technology

[0002] The depletion development mechanism after fracturing in shale oil reservoirs differs significantly from that of conventional reservoirs. Firstly, the SRV (Self-Recovery Vessel) control area after fracturing is the primary drainage zone for shale oil. With the original geological parameters of the shale reservoir unchanged, fractures effectively increase the contact area between the matrix and water, reducing seepage resistance. The conductivity of artificial fractures contributes to the recovery rate. Secondly, formation elastic energy is the primary energy source in the depletion development process after fracturing. Formation elastic energy includes three types of elastic energy: fracturing fluid elastic energy, reservoir fluid elastic energy, and reservoir rock elastic energy, all of which significantly contribute to the recovery rate. Clarifying the quantitative contributions of these different factors to production and recovery rate at different production stages will provide technical support for targeted optimization of shale oil production technology policies to reduce decline rates, improve recovery rates, and enhance subsequent energy replenishment, thereby improving the effectiveness of shale oil development.

[0003] However, the quantitative contribution of artificial fractures and different formation elastic energies to the recovery rate of shale oil has not yet been systematically studied and evaluated. Firstly, the contribution of the conductivity of artificial fractures to the recovery rate is not considered. Secondly, the increase in elastic energy from the external fracturing fluid after volumetric fracturing is not considered; this energy is mainly concentrated in the near-wellbore fracturing zone. Thirdly, the influence of the dissolved gas-oil ratio on the elastic energy of reservoir fluids is not fully considered. Fourthly, the contribution of the above-mentioned factors at different production times to production and the final recovery rate is not evaluated. For example, invention patent CN112814669A discloses a method and system for predicting the full life cycle recovery rate of shale oil reservoirs, and publishes a recovery rate prediction model for elastic drive and dissolved gas drive in the depletion development process of shale oil based on the principle of material balance. However, this invention patent does not consider the influence of fracturing fluid and artificial fractures when calculating the elastic recovery rate, nor does it distinguish and quantify different types of elastic energy. Furthermore, it only derives the final contribution of different factors to the recovery rate, and cannot calculate the contribution of different production times to the recovery rate.

[0004] In summary, the existing technology has the following drawbacks: 1. The contribution of artificial fracture conductivity to recovery rate was not considered; 2. The increased elastic properties of the external fracturing fluid after volumetric fracturing were not considered; 3. The different types of elastic energy were not differentiated or quantitatively characterized; 4. The contribution of the above-mentioned factors to yield and final recovery rate at different production times was not evaluated. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, the present invention aims to provide a method for evaluating the contribution of artificial fractures and formation energy to the recovery rate of shale oil. By obtaining the contribution of artificial fractures and formation energy to the recovery rate, the present invention quantifies the impact of the conductivity of artificial fractures, the elastic properties of fracturing fluid, the elastic properties of reservoir fluid, and the elastic properties of reservoir rock at different production times on production and the final recovery rate, providing an important basis for subsequent exploitation strategies and optimization.

[0006] To achieve the above objectives, the present invention employs the following technical solution: In a first aspect, the present invention provides a method for evaluating the contribution of artificial fractures and formation energy to oil recovery in shale oil, comprising the following steps: Construct a detailed three-dimensional reservoir geological model for shale oil platforms; A three-dimensional fine reservoir geological model containing natural fractures was constructed based on the three-dimensional fine reservoir geological model. Artificial fractures are loaded into a three-dimensional fine reservoir geological model containing natural fractures, and the conductivity of the artificial fractures is assigned to obtain a matrix-fracture model. The production rate of the first single well is obtained based on the matrix-fracture model. The fracturing fluid elastic properties are assigned to the matrix-fracture model, and the second single-well production rate is obtained based on the matrix-fracture model after assigning the fracturing fluid elastic properties. The reservoir fluid elastic properties are assigned to the matrix-fracture model after fracturing fluid elastic properties are assigned, and the production rate of the third single well is obtained based on the matrix-fracture model after assigning reservoir fluid elastic properties. The elastic properties of the reservoir rock were assigned to the matrix-fracture model after the reservoir fluid elastic properties were assigned, and the production of the fourth single well was obtained based on the matrix-fracture model after the reservoir rock elastic properties were assigned. The production rates of the first, second, third, and fourth wells at different production times were obtained. Based on these production rates, the contributions of artificial fractures and formation energy to shale oil production and ultimate recovery rate were determined.

[0007] Secondly, the present invention provides a system for obtaining the recovery contribution rate of artificial fractures and formation energy, comprising: 3D Fine Reservoir Geological Model Construction Module: Used to construct a 3D fine reservoir geological model for shale oil platforms; Natural fracture distribution model construction module: used to construct a three-dimensional fine reservoir geological model containing natural fractures based on the three-dimensional fine reservoir geological model; The first single-well production acquisition module is used to load artificial fractures into a three-dimensional fine reservoir geological model containing natural fractures, assign values ​​to the conductivity of artificial fractures, obtain a matrix-fracture model, and obtain the first single-well production based on the matrix-fracture model. The second single-well production acquisition module is used to assign values ​​to the fracturing fluid elastic properties of the matrix-fracture model and obtain the second single-well production based on the matrix-fracture model after assigning the fracturing fluid elastic properties. The third single-well production acquisition module is used to assign reservoir fluid elastic properties to the matrix-fracture model after assigning fracturing fluid elastic properties, and to acquire the third single-well production based on the matrix-fracture model after assigning reservoir fluid elastic properties. The fourth single-well production acquisition module is used to assign reservoir rock elastic properties to the matrix-fracture model after assigning reservoir fluid elastic properties, and to acquire the production of the fourth single well based on the matrix-fracture model after assigning reservoir rock elastic properties. Contribution Rate Acquisition Module: Used to acquire the production output of the first, second, third, and fourth wells at different production times, and to acquire the contribution of artificial fractures and formation energy to shale oil production and ultimate recovery rate based on the production output of the first, second, third, and fourth wells at different production times.

[0008] Thirdly, the present invention provides an electronic device, comprising: a processor; a memory for storing computer program instructions; and steps for implementing an evaluation method for obtaining the contribution of artificial fractures and formation energy to oil recovery in shale oil when executing the computer program.

[0009] Fourthly, the present invention provides a storage medium storing computer program instructions, which are loaded and executed by a processor to perform an evaluation method for obtaining the contribution of artificial fractures and formation energy to the recovery rate of shale oil.

[0010] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention constructs a three-dimensional fine-grained reservoir geological model containing natural fractures using a three-dimensional fine-grained reservoir geological model of a shale oil platform. This provides a direct understanding of the shale oil matrix and natural fractures, facilitating subsequent artificial fracture design and recovery contribution rate assessment. Artificial fractures are loaded into the three-dimensional fine-grained reservoir geological model containing natural fractures, and their conductivity is assigned, resulting in a matrix-fracture model. The production rate of the first single well is obtained based on this model, allowing for a preliminary assessment of the production enhancement effect of artificial fractures. The matrix-fracture model is then assigned fracturing fluid elastic properties, and the production rate of the second single well is obtained, providing a preliminary assessment of the contribution of fracturing fluid elastic properties to production. The matrix-fracture model with assigned fracturing fluid elastic properties is then assigned reservoir fluid elastic properties, and the production rate of the third single well is obtained, providing a preliminary assessment of the contribution of reservoir fluid elastic properties to production. Finally, the matrix-fracture model with assigned reservoir fluid elastic properties is assigned reservoir rock elastic properties, and the production rate of the fourth single well is obtained, providing a preliminary assessment of the contribution of reservoir rock elastic properties to production. This study obtains the production rates of the first, second, third, and fourth wells at different production stages. Based on these production rates, the contributions of artificial fractures and formation energy to shale oil production and ultimate recovery rate are determined. By using well production data from multiple time periods across different stages, the contributions of artificial fractures and formation energy to shale oil production and ultimate recovery rate can be quantified. This provides a clear demonstration of the roles of artificial fractures and formation energy in shale oil extraction, offering crucial information for subsequent extraction strategies and optimization.

[0011] 2. The system of this invention includes a three-dimensional fine reservoir geological model construction module, a natural fracture distribution model construction module, a first single-well production acquisition module, a second single-well production acquisition module, a third single-well production acquisition module, a fourth single-well production acquisition module, and a contribution rate acquisition module. The three-dimensional fine reservoir geological model construction module is used to construct a three-dimensional fine reservoir geological model of a shale oil platform; the natural fracture distribution model construction module is used to construct a three-dimensional fine reservoir geological model containing natural fractures based on the three-dimensional fine reservoir geological model; the first single-well production acquisition module is used to load artificial fractures into the three-dimensional fine reservoir geological model containing natural fractures and assign values ​​to the conductivity of the artificial fractures to obtain a matrix-fracture model, and obtain the first single-well production based on the matrix-fracture model; the second single-well production acquisition module is used to assign values ​​to the fracturing fluid elastic properties of the matrix-fracture model, and obtain the second single-well production based on the matrix-fracture model after assigning the fracturing fluid elastic properties; the third single-well production acquisition module is used to assign values ​​to the fracturing fluid... The matrix-fracture model, after being evaluated for its elastic properties, assigns values ​​to the reservoir fluid elastic properties. Based on this, the production rate of the third well is obtained. The fourth well production rate module assigns values ​​to the reservoir rock elastic properties of the matrix-fracture model after the reservoir fluid elastic properties are applied, and the production rate of the fourth well is obtained. The contribution rate acquisition module obtains the production rates of the first, second, third, and fourth wells at different production times, and uses these production rates to determine the contributions of artificial fractures and formation energy to shale oil production and ultimate recovery. These modules work together to obtain the contribution of artificial fractures and formation energy to the recovery rate, quantifying the impact of artificial fracture conductivity, fracturing fluid elastic properties, reservoir fluid elastic properties, and reservoir rock elastic properties on production and ultimate recovery at different production times. This provides crucial information for subsequent exploitation strategies and optimization.

[0012] 3. The electronic equipment, storage medium, and computer program products of this invention can also obtain the contribution of artificial fractures and formation energy recovery rate in shale oil, quantify the impact of artificial fracture conductivity, fracturing fluid elasticity, reservoir fluid elasticity, and reservoir rock elasticity on production and final recovery rate at different production times, and provide important basis for subsequent exploitation strategies and optimization. Attached Figure Description

[0013] Figure 1 This is a flowchart of the method of the present invention; Figure 2 This is a planar distribution diagram of porosity in the geological model of this invention; Figure 3 This is a three-dimensional spatial distribution diagram of natural cracks in this invention; Figure 4Geological models considering natural fractures and matrix, and distribution maps of artificial fractures in horizontal wells, are provided for the present invention. Figure 5 This is a curve showing the change in permeability of artificial fractures as a function of pressure. Figure 6 The curves show the variation of single-well production under different conditions; Figure 7 A comparison of the contribution of various factors to the recovery rate at different production stages during shale oil development; Figure 8 The contribution of each factor to the final recovery rate; Figure 9 This is a connection diagram of the system modules of the present invention. Detailed Implementation

[0014] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0015] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0016] The present invention will now be described in further detail with reference to the accompanying drawings: See Figure 1 This invention discloses a method for evaluating the contribution of artificial fractures and formation energy to oil recovery in shale oil, comprising the following steps: S1. Construct a detailed three-dimensional reservoir geological model of the shale oil platform, as detailed below: A detailed three-dimensional reservoir geological model of the shale oil platform was constructed based on single-well logging interpretation data, single-well fine-layer data, 3D seismic data, well logging data, and actual trajectory profile data of single wells, as detailed below: Using finely layered single-well data, and under the constraints of 3D seismic data volumes, combined with 3D seismic inter-well structural interpretation and single-well actual drilling trajectory data, a virtual well is established to finely constrain the inter-well structural trend. The corner point method is then used to establish a 3D structural model. Based on the three-dimensional structural model, a three-dimensional lithofacies model is established using single-well logging interpretation data, well logging data, and three-dimensional seismic data volume as constraints, and employing seismic constraints and stochastic modeling methods. A three-dimensional property model is established based on the three-dimensional lithofacies model. In the process of establishing the three-dimensional property model, the property model is based on the lithological iteration constraint model. The clay content model and porosity model are constrained by the natural gamma model, and the permeability model and saturation model are constrained by the porosity model. Based on actual trajectory profile data of a single horizontal well, and utilizing local variation functions, virtual wells, and empirical knowledge, the three-dimensional structural model, three-dimensional lithofacies model, and three-dimensional attribute model are iteratively constrained and adjusted to obtain a fine three-dimensional reservoir geological model of the oil platform.

[0017] S2. Construct a three-dimensional fine-grained reservoir geological model containing natural fractures based on the three-dimensional fine-grained reservoir geological model, as detailed below: A detailed three-dimensional reservoir geological model containing natural fractures was established based on the combination of a three-dimensional fine reservoir geological model, imaging logging data, core observation data, three-dimensional seismic ant bodies, variance volumes, and curvature properties, as detailed below: Acquire imaging logging data, core observation data, 3D seismic ant volume, variance volume, and curvature properties; By analyzing the development characteristics of mesoscale natural fractures in a three-dimensional fine reservoir geological model using three-dimensional seismic ant volume, variance volume, and curvature properties, fracture slices are extracted, and a deterministic method is used to model mesoscale fractures based on the fracture slices to obtain a mesoscale fracture model. Small-scale fracture density curves were established based on imaging logging data and core observation data. Under the constraint of three-dimensional seismic data, a random method was used to combine the small-scale fracture density curves with the three-dimensional fine reservoir geological model to model small-scale fractures, thus obtaining a small-scale fracture model.

[0018] S3. Artificial fractures are loaded into a three-dimensional fine reservoir geological model containing natural fractures, and the conductivity of the artificial fractures is assigned to obtain a matrix-fracture model. The production rate of the first single well is obtained based on the matrix-fracture model, as follows: By combining engineering parameters of shale oil horizontal well fracturing construction and downhole microseismic fracture monitoring data, the distribution of artificial fracturing network was simulated. Artificial fractures were loaded into a three-dimensional fine reservoir geological model containing natural fractures to construct a matrix-fracture model that includes the conductivity of artificial fractures. The production rate of the first single well under the artificial fracture conductivity conditions at different times was obtained by simulation using the matrix-fracture model.

[0019] S4. Assign values ​​to the fracturing fluid elastic properties of the matrix-fracture model, and obtain the second single-well production rate based on the matrix-fracture model after assigning the fracturing fluid elastic properties; S5. Assign reservoir fluid elastic properties to the matrix-fracture model after assigning fracturing fluid elastic properties, and obtain the third single-well production based on the matrix-fracture model after assigning reservoir fluid elastic properties; S6. Assign values ​​to the reservoir rock elastic properties of the matrix-fracture model after assigning reservoir fluid elastic properties, and obtain the production rate of the fourth single well based on the matrix-fracture model after assigning reservoir rock elastic properties. S7. Obtain the production rates of the first, second, third, and fourth wells at different production times. Based on these production rates, determine the contributions of artificial fractures and formation energy to shale oil production and ultimate recovery. Formation energy includes the elastic energy of fracturing fluid, the elastic energy of reservoir fluids, and the elastic energy of reservoir rock, as detailed below: The contribution rate of artificial fracture conductivity to production was obtained based on the production output of the first and fourth wells.

[0020] in, The contribution of artificial fracture conductivity to production rate. This is the production rate of the first single well. This is the production output of the fourth single well; The contribution rate of fracturing fluid elastic properties to production was obtained based on the production output of the first, second, and fourth wells.

[0021]

[0022] in, The contribution rate of fracturing fluid elastic properties to production. This is the production rate of the first single well. This is the second single-well production. This is the fourth single-well production. This represents the increase in production from the second well relative to the first well. The contribution rate of reservoir fluid elastic properties to production was obtained based on the production rates of the second, third, and fourth wells.

[0023]

[0024] in, The contribution rate of reservoir fluid elastic properties to production. This is the second single-well production. This is the production of the third single well. This is the fourth single-well production. This represents the increase in production from the third well relative to the production from the second well. The contribution rate of reservoir rock elastic properties to production was obtained based on the production output of the third and fourth wells.

[0025]

[0026] in, The contribution rate of reservoir rock elastic properties to production. This is the production of the third single well. This is the fourth single-well production. This represents the increase in production of the fourth well relative to the production of the third well. The contribution of artificial fracture conductivity to the final recovery rate is obtained based on the production of the first and fourth single wells over several years.

[0027] in, The contribution of artificial fracture conductivity to final recovery rate. This is the production rate of the first single well. This is the fourth single-well production. Total number of years; The contribution rate of fracturing fluid elastic properties to the final recovery rate is obtained based on the production of the first, second, and fourth wells over several years.

[0028] in, The contribution rate of fracturing fluid elastic properties to the final recovery rate. This is the fourth single-well production. This represents the increase in production from the second well relative to the first well. Total number of years; The contribution rate of reservoir fluid elastic properties to the final recovery rate is obtained based on the production rates of the second, third, and fourth wells over several years.

[0029] in, The contribution rate of reservoir fluid elastic properties to ultimate recovery rate. This is the fourth single-well production. This represents the increase in production from the third well relative to the second well. Total number of years; The contribution of reservoir rock elastic properties to the final recovery rate is obtained based on the production of the third and fourth wells over several years.

[0030]

[0031] in, The contribution of reservoir rock elastic properties to the final recovery rate. This is the fourth single-well production. This represents the increase in production of the fourth well relative to the production of the third well. This represents the total number of years.

[0032] See Figure 1 In another feasible embodiment of the present invention, the following adaptive modifications are made as needed, including the following steps: constructing a three-dimensional fine reservoir geological model of the shale oil platform, and constructing a three-dimensional fine reservoir geological model containing natural fractures based on the three-dimensional fine reservoir geological model. By constructing a three-dimensional fine reservoir geological model containing natural fractures, the matrix and natural fracture conditions of the shale oil reservoir can be intuitively understood, which facilitates the subsequent design of artificial fractures and the assessment of recovery contribution.

[0033] Artificial fractures were loaded into a three-dimensional fine-grained reservoir geological model containing natural fractures, and the conductivity of the artificial fractures was assigned values ​​to obtain a matrix-fracture model. The production rate of the first single well was obtained based on the matrix-fracture model. The matrix-fracture model can reflect the interaction between artificial fractures and matrix and natural fractures, as well as their combined influence on fluid flow. Obtaining the production rate of the first single well can provide a preliminary assessment of the effect of artificial fractures on production improvement.

[0034] The matrix-fracture model was assigned values ​​for the elastic properties of the fracturing fluid. The production rate of the second well was then obtained based on this assigned value. The matrix-fracture model with these assigned values ​​reflects the increase in reservoir pressure and energy brought about by the fracturing fluid after fracturing in shale oil wells, and further simulates the impact of changes in the elastic properties of the fracturing fluid on production. Obtaining the production rate of the second well allows for a preliminary assessment of the contribution of the fracturing fluid's elastic properties to overall production.

[0035] The matrix-fracture model after assigning fracturing fluid elastic properties is then used to assign reservoir fluid elastic properties. Based on the matrix-fracture model after assigning reservoir fluid elastic properties, the production rate of the third well is obtained. This is used to simulate the flow and distribution of fluid in the matrix and fractures, as well as the impact of fluid elastic properties on crude oil fluidity during production and the energy released by volume expansion as pressure decreases on production. Obtaining the production rate of the third well can provide a preliminary assessment of the contribution of fluid elastic properties to production.

[0036] The reservoir rock elastic energy was assigned to the matrix-fracture model after assigning reservoir fluid elastic energy, and the production rate of the fourth well was obtained based on the matrix-fracture model after assigning reservoir rock elastic energy. This model is used to simulate the supporting and constraining effect of rock on the matrix and fractures, as well as the impact of the elastic energy released by the change in rock pore volume with pressure during the production process on the production rate. Obtaining the production rate of the fourth well can provide a preliminary assessment of the contribution of rock elastic energy to the production rate.

[0037] This invention obtains the production rates of the first, second, third, and fourth wells at different production times. Based on these production rates, it determines the contributions of artificial fractures and formation energy to shale oil production and ultimate recovery. By comparing the well production rates obtained at different times over several years in different steps, the contributions of artificial fractures and formation energy to shale oil production and ultimate recovery can be quantified. This step is the core of the invention, visually demonstrating the role of artificial fractures and formation energy in shale oil extraction, providing crucial information for subsequent extraction strategies and optimization.

[0038] This invention gradually constructs and assigns values ​​to models, progressively simulating and analyzing the impact of artificial fractures and formation energy on shale oil recovery, ultimately obtaining accurate recovery contribution and providing a scientific basis for shale oil extraction.

[0039] Example 2: This embodiment discloses a method for evaluating the contribution of artificial fractures and formation energy to oil recovery in shale oil, comprising the following steps: S1: Establish a detailed 3D reservoir geological model for the shale oil platform. The specific steps are as follows: S11. Prepare single-well logging interpretation data, single-well fine-layer data, 3D seismic data volume, logging data, and single-well actual trajectory profile data. The single wells include exploration and evaluation wells and horizontal wells within the research platform range. The single-well logging interpretation data includes porosity, permeability, oil saturation, clay content, and natural gamma.

[0040] S12. Using the detailed single-well and detailed stratification data of the exploration and evaluation wells in S11, under the constraints of the three-dimensional seismic data volume, combined with the three-dimensional seismic inter-well structural interpretation and single-well actual drilling trajectory data, a virtual well is established to finely constrain the inter-well structural trend, and a three-dimensional structural model is established using the corner point method.

[0041] S13. Based on the three-dimensional structural model established in S12, a three-dimensional lithofacies model is established using the single-well logging interpretation data, well logging data and three-dimensional seismic data volume in S11 as constraints, and seismic constraints and stochastic modeling methods are adopted. S14. Based on the three-dimensional lithofacies model established in S13, a three-dimensional attribute model is established. The three-dimensional attribute model includes a natural gamma model, a clay content model, a porosity model, a permeability model, and a saturation model. The attribute model is constrained by lithological iteration. The natural gamma model constrains the clay content model and the porosity model, and the porosity model constrains the permeability model and the saturation model.

[0042] S15. Based on the actual trajectory profile data of a single horizontal well, and using local variation functions, virtual wells, and empirical knowledge, iterative constraint adjustments are made to the three-dimensional structural model, three-dimensional lithofacies model, and three-dimensional attribute model to obtain a three-dimensional fine reservoir geological model.

[0043] S2: Establish a detailed 3D reservoir geological model of a shale oil platform containing natural fractures. This model includes both medium-to-large-scale and small-scale detailed 3D reservoir geological models containing natural fractures. The specific steps are as follows: S21. Acquire imaging logging data, core observation data, 3D seismic ant volume, variance volume and curvature properties; S22. By analyzing the development characteristics of medium- and large-scale natural fractures in the three-dimensional fine reservoir geological model through three-dimensional seismic ant volume, variance volume and curvature properties, fracture slices are extracted, and a deterministic method is used to model medium- and large-scale fractures based on the fracture slices to obtain a three-dimensional fine reservoir geological model containing medium- and large-scale natural fractures.

[0044] S23. Based on imaging logging data and core observation data, establish small-scale fracture density curves. Under the constraint of three-dimensional seismic data, use a random method to combine the small-scale fracture density curves to establish small-scale fracture modeling in a three-dimensional fine reservoir geological model, and obtain a small-scale three-dimensional fine reservoir geological model containing natural fractures.

[0045] S3: Simulate and calculate the impact of artificial fractures on single-well production. The specific steps are as follows: S31. Based on S1 and S2, and combining the engineering parameters of shale oil horizontal well fracturing construction and downhole microseismic fracture monitoring data, simulate the distribution of artificial fracture network. Using the reservoir numerical simulation software ECLIPS or other reservoir numerical simulation software, load artificial fractures into a three-dimensional fine reservoir geological model containing natural fractures. The relative permeability of the matrix zone and the artificial fracture zone is obtained from the relative permeability curve data of laboratory shale oil matrix cores and fracture cores, respectively. Assign values ​​to the conductivity of artificial fractures to construct a matrix-fracture model that includes the conductivity of artificial fractures.

[0046] S32 shale oil reservoirs are tight and have developed micro- and nano-pore throats. Without fracturing to create fractures and replenish energy, there is no industrial oil flow. Therefore, the three-dimensional fine-grained reservoir geological model containing natural fractures does not contribute to the recovery rate. Thus, artificial fractures are added to the three-dimensional fine-grained reservoir geological model containing natural fractures, and their conductivity is assigned. A matrix-fracture model incorporating the conductivity of artificial fractures is constructed. The average single-well production under the matrix-fracture model for 15 years is simulated and calculated, obtaining the first single-well production under different artificial fracture conductivity conditions within 15 years. The assignment of the flow-guiding capacity of artificial cracks takes into account the spatiotemporal changes of attributes during actual production.

[0047] S4: Simulation calculation of the impact of artificial fractures and fracturing fluid elastic properties on single-well production, as detailed below: Based on S3, the elastic energy of the fracturing fluid is assigned, and the elastic energy of the fracturing fluid considering the replenishment of external fluid during volumetric fracturing is added. The elastic energy of the fracturing fluid is mainly reflected by increasing the formation pressure level through the injection of equivalent fracturing fluid. The average single-well production over 15 years is simulated and calculated considering the conductivity of artificial fractures and the elastic energy of the injected hydraulic fracturing fluid. The second single-well production under the influence of artificial fracture conductivity and the elastic energy of the injected hydraulic fracturing fluid at different times within 15 years is obtained. And compare it with S3 to calculate the increase in production of the second well relative to the production of the first well. , .

[0048] S5: Simulation calculation of the impact of artificial fractures, fracturing fluid, and reservoir fluid elastic properties on single-well production, as detailed below: Based on S4, the fluid elastic energy was assigned, the dissolved gas-oil ratio parameter was changed to the parameters of the actual reservoir, and the matching PVT parameter field was adjusted. The average single-well production over 15 years was simulated and calculated considering the conductivity of artificial fractures, the elastic energy of fracturing fluid, and the elastic energy of reservoir fluid. The third single-well production under the influence of the conductivity of artificial fractures, the elastic energy of fracturing fluid, and the elastic energy of fluid fluid at different times within 15 years was obtained. And compare it with S4 to calculate the increase in production of the third well relative to the production of the second well. , .

[0049] S6: Simulation calculation of the impact of artificial fractures, fracturing fluid, reservoir fluid elastic properties, and reservoir rock elastic properties on single-well production, as detailed below: Based on S5, the rock compressibility coefficient in the numerical model of the S31 numerical simulation software was adjusted. The average single-well production over 15 years was simulated and calculated considering the conductivity of artificial fractures, the elastic energy of fracturing fluid, the elastic energy of reservoir fluid, and the elastic energy of reservoir rock. The production of the fourth single well under the influence of artificial fracture conductivity, fracturing fluid elastic energy, reservoir fluid elastic energy, and reservoir rock elastic energy at different times within 15 years was obtained. And compared with S5, the increase in production of the fourth well relative to the production of the third well was calculated. , .

[0050] S7: Based on the data obtained from S3, S4, S5, and S6, calculate the quantitative contributions of artificial fracture conductivity, fracturing fluid elastic properties, reservoir fluid elastic properties, and reservoir rock elastic properties to production and recovery rate, as detailed below: The contributions of each factor to output at different production times are as follows: Calculate the contribution of artificial fracture conductivity to production:

[0051] in, The contribution rate of artificial fracture flow conduction capacity to production; Calculate the contribution rate of fracturing fluid elastic properties to production:

[0052] in, The contribution rate of fracturing fluid elastic properties to production; Calculate the contribution rate of reservoir fluid elastic properties to production:

[0053] in, The contribution rate of reservoir fluid elastic properties to production; Calculate the contribution rate of reservoir rock elastic properties to production:

[0054] in, The contribution rate of reservoir rock elastic properties to production; The contributions of each factor to the final recovery rate are as follows, and the total time used in this example is 15 years: Calculate the contribution of artificial fracture conductivity to final recovery:

[0055] in, The contribution of artificial fracture conductivity to the final recovery rate; Calculate the contribution of fracturing fluid elastic properties to the final recovery rate:

[0056] in, The contribution rate of fracturing fluid elastic properties to the final recovery rate; Calculate the contribution of reservoir fluid elastic properties to ultimate recovery:

[0057] in, The contribution rate of reservoir fluid elastic properties to the final recovery rate; Calculate the contribution of reservoir rock elastic properties to the final recovery rate:

[0058] in, This represents the contribution of the reservoir rock's elastic properties to the final recovery rate.

[0059] This invention combines the depletion-type development mechanism after volumetric fracturing in shale oil production with an actual shale oil well development model to quantitatively evaluate the contribution of artificial fracture conductivity and three types of elastic energy—fracturing fluid elastic energy, reservoir fluid elastic energy, and reservoir rock elastic energy—to the recovery rate. This method can clearly define the quantitative contribution of artificial fractures and different formation energies to production and the final recovery rate at different time periods. It has key guiding significance for optimizing the amount of fracturing fluid injected into the formation and fracturing parameters to improve the conductivity of artificial fractures and fully utilize the effects of different energies to optimize the "smoldering and draining" production technology policy, thereby reducing decline and improving the recovery rate. At the same time, it can also provide technical support for subsequent energy replenishment.

[0060] Example 3: Please see Figure 1 As shown, this invention provides a method for evaluating the contribution of artificial fractures and formation energy to oil recovery in shale oil, the specific process of which includes: S10: Establish a three-dimensional, detailed reservoir geological model for shale oil platforms; The specific steps are as follows: S101. Prepare single-well logging interpretation data, single-well fine-layer data, 3D seismic data volume, logging data, and single-well actual trajectory profile data. The single wells include exploration and evaluation wells and horizontal wells within the research platform range. The single-well logging interpretation data includes porosity, permeability, oil saturation, shale content, and natural gamma.

[0061] S102. Using the detailed single-well and detailed stratification data of the exploration and evaluation wells in step S101, under the constraints of the three-dimensional seismic data volume, combined with the three-dimensional seismic inter-well structural interpretation and single-well actual drilling trajectory data, a virtual well is established, the inter-well structural trend is finely constrained, and a three-dimensional structural model is established using the corner point method.

[0062] S103. Based on the three-dimensional structural model established in step S102, a three-dimensional lithofacies model is established using the well logging interpretation data, well logging data and three-dimensional seismic data volume in S101 as constraints, and the seismic constraint and stochastic modeling methods are adopted. S104. Based on the constraints of the three-dimensional lithofacies model established in step S103, the natural gamma model is used as a co-variable in the process of establishing the clay content model and the porosity model. The porosity model is also used as a co-variable in the establishment of the permeability model, the saturation model and the permeability model. The three-dimensional attribute model is established by using phase control and stochastic modeling methods. S105. Based on the actual trajectory profile data of a single horizontal well, using local variation functions, virtual wells, and empirical knowledge, iterative constraint adjustments are made to the three-dimensional structural model, three-dimensional lithofacies model, and three-dimensional attribute model to obtain a three-dimensional fine reservoir geological model.

[0063] The corner point method, stochastic modeling method, local variation function, and single-well fine stratification data used are all well-known technologies in this field and will not be described in detail here; the models established in steps S102 to S105 are all established using geological modeling software as the implementation tool.

[0064] The shale oil in a certain oilfield belongs to a semi-deep to deep lacustrine gravity flow sedimentary reservoir with an average porosity of 8.9% and an average permeability of 0.11 mD. Based on marker bed constraints, cyclic correlation, and fine-grained layered data from single wells combined with well-seismic analysis, an initial three-dimensional structural model of the reservoir was established. On this basis, combined with 3D seismic inter-well structural interpretation and single-well drilling trajectory data, a virtual well was established to finely constrain the inter-well structural trends, and a three-dimensional structural model was built. Based on the three-dimensional structural model, using single-well logging interpretation data, well logging data, and 3D seismic data volumes as constraints, the sand body distribution characteristics between wells were characterized, and a three-dimensional lithofacies model was established. Based on the constraints of the three-dimensional lithofacies model, a three-dimensional attribute model and a three-dimensional fine-grained reservoir geological model were established, such as... Figure 2 As shown.

[0065] S20: Establish a detailed three-dimensional reservoir geological model of a shale oil platform containing natural fractures. This model includes both medium- and large-scale models and small-scale models. The specific steps are as follows: S201. Acquire imaging logging data, core observation data, 3D seismic ant volume, variance volume and curvature properties; S202. By using three-dimensional seismic ant bodies, variance volumes, and curvature attributes, the development characteristics of medium- and large-scale natural fractures in the three-dimensional fine reservoir geological model are characterized in three-dimensional space. Fracture slices are extracted, and a deterministic method is used to establish a three-dimensional fine reservoir geological model containing medium- and large-scale natural fractures in a hierarchical grouping system.

[0066] S203. Based on imaging logging data and core observation data, establish small-scale fracture density curves. Using a stochastic modeling method, establish a fracture density model. Under three-dimensional seismic constraints, establish small-scale three-dimensional fine reservoir geological models containing natural fractures in layers within the three-dimensional fine reservoir geological model.

[0067] The Chang 7 shale oil reservoir in a certain oilfield mainly develops medium-to-large-scale fractures trending NE-E and EST, with most of the fractures extending upwards into the Jurassic-Cretaceous system, ranging from 10 to 40 km in length. Small-scale fractures are predominantly NE-E and EST-oriented, with high dip angles (>85%), an average fracture density of 0.12 fractures / meter, and an average fracture height of 80 cm. Figure 3 .

[0068] In the embodiments, loading can be established based on the understanding of actual natural fractures in different reservoirs.

[0069] S30: Simulate and calculate the impact of artificial fractures on single-well production. The specific steps are as follows: S301. Based on S1 and S2, and combining engineering parameters of shale oil horizontal well fracturing construction and downhole microseismic fracture monitoring data, the distribution of artificial fracture network is simulated. Artificial fractures are loaded into a three-dimensional fine reservoir geological model containing natural fractures using reservoir numerical simulation software ECLIPS or other reservoir numerical simulation software. The relative permeability of the matrix zone and the artificial fracture zone is obtained from the relative permeability curve data of laboratory shale oil matrix cores and fracture cores, respectively. The conductivity of artificial fractures is assigned, and a matrix-fracture model containing the conductivity of artificial fractures is constructed.

[0070] The S302 shale oil reservoir is dense and has developed micro- and nano-pore throats. Without fracturing to create fractures and replenish energy, there is no industrial oil flow. Therefore, the three-dimensional fine-grained reservoir geological model containing natural fractures does not contribute to the recovery rate. Thus, artificial fractures are loaded onto the three-dimensional fine-grained reservoir geological model containing natural fractures, and their conductivity is assigned. A matrix-fracture model incorporating the conductivity of artificial fractures is constructed. The average single-well production under the matrix-fracture model for 15 years is simulated and calculated, obtaining the single-well production under different artificial fracture conductivity conditions within 15 years. The permeability of artificial cracks is assigned a value that takes into account the changes over time during actual production.

[0071] The original formation pressure in Block L18 of the Chang 7 shale oil field was 16 MPa, the formation temperature was 57.2℃, and the original dissolved gas-oil ratio was set at 20m. 3 / t, oil layer thickness 7.8m, average porosity 8.9%, average permeability 0.11mD, oil saturation 68%, formation crude oil viscosity 1.3mPa·s, bubble point pressure 10MPa, horizontal well length in matrix-fracture model is 1500m, well spacing is 400m, number of fractured sections per 100m is 1.3, fluid injection volume per 100m is 1200m³. 3 Based on the actual fracturing engineering parameters of shale oil horizontal wells and the fitting and matching of downhole micro-seismic monitoring data, the half-fracture length is found to be 130-175m, with a non-uniform distribution, such as... Figure 4 Based on actual post-press imaging logging and coring data from the mine, the depth was set to 30m. The permeability value of the artificial fractures was assigned to account for changes over time during actual production. Figure 5 Based on this model, the production rate of a single well under the action of artificial fractures at different times over 15 years was simulated. ,See Figure 6 As shown.

[0072] S40: Simulate and calculate the impact of artificial fractures and fracturing fluid elastic properties on single-well production; Based on S30, the elastic performance of the fracturing fluid is considered in addition to the external fluid injection during volumetric fracturing. This elastic performance is primarily manifested by increasing the formation pressure level through the injection of equivalent fracturing fluid. In the example block, the average single-well fluid injection volume for horizontal wells is 25927 m³. 3 After injecting equivalent fracturing fluid, the formation pressure increased from 16 MPa to 19 MPa. Simulations were performed considering the artificial fractures and the elastic energy of the injected hydraulic fracturing fluid over 15 years to calculate the average well production. The well production under the influence of the artificial fracture conductivity and the elastic energy of the injected hydraulic fracturing fluid at different times within the 15-year period was obtained. See Figure 6 And by comparing with S30, the increase in single-well production was calculated. Compared to S30, cumulative oil production increased by 17.4%.

[0073] In S50: Simulation calculation of the impact of artificial fractures, fracturing fluid, and hydroelastic properties on single-well production; Previous indoor experimental studies have shown that the elastic properties of reservoir fluids are mainly reflected in the elastic properties of dissolved gas. Therefore, based on S40, the dissolved gas-oil ratio parameter was changed to the parameters of the actual reservoir, from the initial setting of 20m 3 / t adjusted to 105m 3 / t, adjust the matching PVT parameter field, and simulate the average single-well production over 15 years considering the elastic energy of artificial fractures, fracturing fluid, and reservoir fluid. This yields the single-well production under the influence of artificial fracture conductivity, in-situ fluid elastic energy, and reservoir fluid elastic energy at different times within the 15-year period. See Figure 6 The increase in single-well production was calculated by comparing it with S40. Compared to S40, cumulative oil production has increased by 50.7%.

[0074] In S60: Simulate the impact of artificial fractures and fracturing fluid elastic properties, reservoir fluid elastic properties, and rock elastic properties on single-well production; Based on S50, the rock compression coefficient in the model is adjusted to 1*10. -7 kPa -1 The production conditions at that time and the rock compressibility coefficient were 6*10 -6 kPa -1 By comparing production conditions at different times, simulations were performed to calculate the average well production over 15 years under the influence of artificial fracture conductivity, fracturing fluid elasticity, reservoir fluid elasticity, and rock elasticity. This yielded the well production under the influence of artificial fractures, fracturing fluid elasticity, reservoir fluid elasticity, and reservoir rock elasticity at different times within the 15-year period. See Figure 6 The increase in single-well production was calculated by comparing it with S50. Compared to S50, the cumulative increase in oil production was smaller, increasing by only 4.2%.

[0075] In S70: Steps S40, S50 and S60 are based on step S30, which adds an influencing factor to simulate production. Therefore, based on the data obtained in steps S30, S40, S50 and S60, the quantitative contributions of artificial fracture conductivity, fracturing fluid elasticity, reservoir fluid elasticity, and reservoir rock elasticity to production and recovery rate can be calculated by subtracting them in sequence.

[0076] The contributions of each factor to output at different production times are as follows: Calculate the contribution of artificial fracture conductivity to production:

[0077] in, The contribution rate of artificial fracture flow conduction capacity to production; Calculate the contribution rate of fracturing fluid elastic properties to production:

[0078] in, The contribution rate of fracturing fluid elastic properties to production; Calculate the contribution rate of reservoir fluid elastic properties to production:

[0079] in, The contribution rate of reservoir fluid elastic properties to production; Calculate the contribution rate of reservoir rock elastic properties to production:

[0080] in, The contribution rate of reservoir rock elastic properties to production; The contributions of each factor to the final recovery rate are as follows: Calculate the contribution of artificial fracture conductivity to final recovery:

[0081] in, The contribution of artificial fracture conductivity to the final recovery rate; Calculate the contribution of fracturing fluid elastic properties to the final recovery rate:

[0082] in, The contribution rate of fracturing fluid elastic properties to the final recovery rate; Calculate the contribution of reservoir fluid elastic properties to ultimate recovery:

[0083] in, The contribution rate of reservoir fluid elastic properties to the final recovery rate; Calculate the contribution of reservoir rock elastic properties to the final recovery rate:

[0084] in, This represents the contribution of the reservoir rock's elastic properties to the final recovery rate.

[0085] like Figure 7 As shown, in the first two years of shale oil development, artificial fractures mainly contribute to production, with a contribution rate of 55-90%. Due to changes in fracture conductivity, their contribution rate decreases over time. The contribution of fluid elastic energy to production increases over time, reaching 30%. The contribution of in-situ fluid elastic energy to production is relatively small, at 9%, while rock elastic energy has the smallest contribution rate, at 4.7%. In the later stages of development, the contributions of each factor to production become more stable. The contribution rate of artificial fractures stabilizes at 43-53%, the contribution rate of fluid elastic energy stabilizes at 33-38%, the contribution rate of in-situ fluid elastic energy stabilizes at around 9%, and the contribution rate of rock fluid elastic energy stabilizes at around 4%.

[0086] like Figure 8As shown, artificial fractures contributed 54.3% to the final recovery rate, fluid elastic energy contributed 32.3%, in-situ fluid elastic energy contributed 9.4%, and rock fluid elastic energy contributed 4.0%. Specifically evaluating the contribution of different energies to the final recovery rate, fluid elastic energy contributed 70.6%, in-situ fluid elastic energy contributed 20.6%, and rock fluid elastic energy contributed 8.8%. These findings provide important evidence for leveraging the advantages of artificial fractures and different elastic energies to optimize shale oil production technology policies at different stages, reduce decline, increase recovery rates, and replenish formation energy in the later stages.

[0087] In summary, given the unique depletion-driven development mode of shale oil after volumetric fracturing, the quantitative contribution of artificial fractures and different formation elastic energies to oil recovery has not been systematically studied and evaluated. This invention, combining the depletion-driven development mechanism of shale oil after volumetric fracturing, establishes a three-dimensional geological model and a matrix-fracture network numerical model suitable for actual shale oil development for simulation calculations. This enables a quantitative evaluation of the contribution of artificial fracture conductivity and three types of elastic energies—fracturing fluid elastic energy, reservoir fluid elastic energy, and reservoir rock elastic energy—to oil recovery. This invention can clearly define the quantitative contribution of artificial fractures and different formation energies to production and the final recovery rate at different production stages. It has key guiding significance for optimizing the amount of fracturing fluid injected into the formation and fracturing parameters to improve the conductivity of artificial fractures and fully utilize the effects of different energies to optimize the "smoldering and draining" production technology policy, thereby reducing decline and increasing recovery. It also provides technical support for subsequent energy replenishment.

[0088] This invention proposes an evaluation method for assessing the contribution of artificial fractures and formation energy to the recovery rate of shale oil. This method is used for the quantitative evaluation of the contribution of artificial fractures and formation energy to the recovery rate of shale oil, addressing the problem in existing technologies where the contribution of artificial fractures and different formation elastic energies to the recovery rate in the depletion-type development of shale oil after volumetric fracturing has not been systematically quantified. It enables the quantitative characterization of the contribution of artificial fracture conductivity to the recovery rate at different times, and the quantitative characterization and comparison of the contribution of three different formation elastic energies—fracturing fluid elastic energy, reservoir fluid elastic energy, and reservoir rock elastic energy—to the recovery rate.

[0089] Based on the above method, this invention discloses an evaluation system for obtaining the contribution of artificial fractures and formation energy to oil recovery in shale oil. (See also...) Figure 9 ,include: 3D Fine Reservoir Geological Model Construction Module: Used to construct a 3D fine reservoir geological model for shale oil platforms; Natural fracture distribution model construction module: used to construct a three-dimensional fine reservoir geological model containing natural fractures based on the three-dimensional fine reservoir geological model; The first single-well production acquisition module is used to load artificial fractures into a three-dimensional fine reservoir geological model containing natural fractures, assign values ​​to the conductivity of artificial fractures, obtain a matrix-fracture model, and obtain the first single-well production based on the matrix-fracture model. The second single-well production acquisition module is used to assign values ​​to the fracturing fluid elastic properties of the matrix-fracture model and obtain the second single-well production based on the matrix-fracture model after assigning the fracturing fluid elastic properties. The third single-well production acquisition module is used to assign reservoir fluid elastic properties to the matrix-fracture model after assigning fracturing fluid elastic properties, and to acquire the third single-well production based on the matrix-fracture model after assigning reservoir fluid elastic properties. The fourth single-well production acquisition module is used to assign reservoir rock elastic properties to the matrix-fracture model after assigning reservoir fluid elastic properties, and to acquire the production of the fourth single well based on the matrix-fracture model after assigning reservoir rock elastic properties. Contribution Rate Acquisition Module: Used to acquire the production output of the first, second, third, and fourth wells at different production times, and to acquire the contribution of artificial fractures and formation energy to shale oil production and ultimate recovery rate based on the production output of the first, second, third, and fourth wells at different production times.

[0090] The various modules of this invention work together to obtain the contribution of artificial fractures and formation energy recovery rate, quantify the impact of artificial fracture conductivity, fracturing fluid elasticity, reservoir fluid elasticity, and reservoir rock elasticity on production and final recovery rate at different production times, and provide important basis for subsequent mining strategies and optimization.

[0091] An electronic device includes: a processor; a memory for storing computer program instructions; and steps for implementing an evaluation method for obtaining the contribution of artificial fractures and formation energy to oil recovery in shale oil when executing the computer program.

[0092] A storage medium storing computer program instructions, which are loaded and executed by a processor, wherein the processor executes an evaluation method for acquiring artificial fractures in shale oil and the contribution of formation energy to the recovery rate.

[0093] A computer program product comprising computer instructions that instruct a computer to execute an evaluation method for acquiring artificial fractures in shale oil and the contribution of formation energy to oil recovery.

[0094] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0095] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0096] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0097] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0098] This invention, based on the unique depletion-type development characteristics of shale oil after volumetric fracturing, establishes an evaluation method for assessing the contribution of artificial fractures and formation energy to oil recovery. It quantitatively evaluates the contribution of artificial fractures and different formation elastic energies to oil recovery, enabling quantitative characterization and comparison of the contributions of artificial fracture conductivity, fracturing fluid elastic energy, reservoir fluid elastic energy, and reservoir rock elastic energy at different production times to production and recovery. This provides technical support for optimizing shale oil production technology policies to reduce decline, improve recovery, and replenish formation energy in the later stages.

[0099] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for evaluating the contribution of artificial fractures and formation energy to oil recovery in shale oil, characterized in that, Includes the following steps: Construct a detailed three-dimensional reservoir geological model for shale oil platforms; A three-dimensional fine reservoir geological model containing natural fractures was constructed based on the three-dimensional fine reservoir geological model. Artificial fractures are loaded into a three-dimensional fine reservoir geological model containing natural fractures, and the conductivity of the artificial fractures is assigned to obtain a matrix-fracture model. The production rate of the first single well is obtained based on the matrix-fracture model. The fracturing fluid elastic properties are assigned to the matrix-fracture model, and the second single-well production rate is obtained based on the matrix-fracture model after assigning the fracturing fluid elastic properties. The reservoir fluid elastic properties are assigned to the matrix-fracture model after fracturing fluid elastic properties are assigned, and the production rate of the third single well is obtained based on the matrix-fracture model after assigning reservoir fluid elastic properties. The elastic properties of the reservoir rock were assigned to the matrix-fracture model after the reservoir fluid elastic properties were assigned, and the production of the fourth single well was obtained based on the matrix-fracture model after the reservoir rock elastic properties were assigned. The production rates of the first, second, third, and fourth wells at different production times were obtained. Based on these production rates, the contributions of artificial fractures and formation energy to shale oil production and ultimate recovery rate were determined.

2. The method for evaluating the contribution of artificial fractures and formation energy to oil recovery in shale oil, as described in claim 1, is characterized in that... The construction of a detailed three-dimensional reservoir geological model for the shale oil platform is as follows: A three-dimensional fine reservoir geological model of the shale oil platform was constructed based on single-well logging interpretation data, single-well fine stratification data, three-dimensional seismic data volume, well logging data, and single-well actual trajectory profile data.

3. The method for evaluating the contribution of artificial fractures and formation energy to oil recovery in shale oil, as described in claim 2, is characterized in that... The detailed three-dimensional reservoir geological model of the shale oil platform is constructed based on single-well logging interpretation data, single-well fine-layer data, 3D seismic data, well logging data, and actual trajectory profile data of single wells, as detailed below: Using finely layered single-well data, and under the constraints of 3D seismic data volumes, combined with 3D seismic inter-well structural interpretation and single-well actual drilling trajectory data, a virtual well is established to finely constrain the inter-well structural trend. The corner point method is then used to establish a 3D structural model. Based on the three-dimensional structural model, a three-dimensional lithofacies model is established using single-well logging interpretation data, well logging data, and three-dimensional seismic data volume as constraints, and employing seismic constraints and stochastic modeling methods. A three-dimensional property model is established based on the three-dimensional lithofacies model. In the process of establishing the three-dimensional property model, the property model is based on the lithological iteration constraint model. The clay content model and porosity model are constrained by the natural gamma model, and the permeability model and saturation model are constrained by the porosity model. Based on actual trajectory profile data of horizontal wells, and utilizing local variation functions, virtual wells, and empirical knowledge, the three-dimensional structural model, three-dimensional lithofacies model, and three-dimensional attribute model are iteratively constrained and adjusted to obtain a fine three-dimensional reservoir geological model of the shale oil platform.

4. The method for evaluating the contribution of artificial fractures and formation energy to oil recovery in shale oil, as described in claim 1, is characterized in that... The construction of a three-dimensional fine reservoir geological model including natural fractures based on the three-dimensional fine reservoir geological model is as follows: A three-dimensional fine reservoir geological model containing natural fractures was established based on the combination of three-dimensional fine reservoir geological model, imaging logging data, core observation data, three-dimensional seismic ant bodies, variance volume, and curvature properties.

5. The method for evaluating the contribution of artificial fractures and formation energy to oil recovery in shale oil, as described in claim 4, is characterized in that... The detailed three-dimensional reservoir geological model, including natural fractures, is established based on a combination of a three-dimensional fine reservoir geological model, imaging logging data, core observation data, three-dimensional seismic ant bodies, variance volumes, and curvature properties, as detailed below: Acquire imaging logging data, core observation data, 3D seismic ant volume, variance volume, and curvature properties; By analyzing the development characteristics of medium- and large-scale natural fractures in the three-dimensional fine reservoir geological model through three-dimensional seismic ant volume, variance volume and curvature properties, fracture slices are extracted, and a deterministic method is used to model medium- and large-scale fractures based on the fracture slices to obtain a three-dimensional fine reservoir geological model containing medium- and large-scale natural fractures. Small-scale fracture density curves were established based on imaging logging data and core observation data. Under the constraint of three-dimensional seismic data, a random method was used to combine the small-scale fracture density curves with the three-dimensional fine reservoir geological model to model small-scale fractures, thus obtaining a small-scale three-dimensional fine reservoir geological model containing natural fractures.

6. The method for evaluating the contribution of artificial fractures and formation energy to oil recovery in shale oil, as described in claim 1, is characterized in that... Artificial fractures are loaded into a three-dimensional fine reservoir geological model containing natural fractures, and the conductivity of the artificial fractures is assigned a value to obtain a matrix-fracture model. The production rate of the first single well is obtained based on the matrix-fracture model, as detailed below: By combining engineering parameters of shale oil horizontal well fracturing construction and downhole microseismic fracture monitoring data, the distribution of artificial fracturing network was simulated. Artificial fractures were loaded into a three-dimensional fine reservoir geological model containing natural fractures to construct a matrix-fracture model that includes the conductivity of artificial fractures. The production rate of the first single well under the artificial fracture conductivity conditions at different times was obtained by simulation using the matrix-fracture model.

7. The method for evaluating the contribution of artificial fractures and formation energy to oil recovery in shale oil, as described in claim 1, is characterized in that... The production rates of the first, second, third, and fourth wells at different production times are obtained. Based on these production rates, the contributions of artificial fractures and formation energy to shale oil production and ultimate recovery rate are determined, as follows: The contribution rate of artificial fracture conductivity to production was obtained based on the production output of the first and fourth wells. The contribution rate of fracturing fluid elastic properties to production was obtained based on the production output of the first, second, and fourth wells. The contribution rate of reservoir fluid elastic properties to production was obtained based on the production rates of the second, third, and fourth wells. The contribution rate of reservoir rock elastic properties to production was obtained based on the production output of the third and fourth wells. To obtain the production output of the first, second, third, and fourth wells over several years; The contribution of artificial fracture conductivity to the final recovery rate is obtained based on the production of the first and fourth single wells over several years. The contribution rate of fracturing fluid elastic properties to the final recovery rate is obtained based on the production of the first, second, and fourth wells over several years. The contribution rate of reservoir fluid elastic properties to the final recovery rate is obtained based on the production rates of the second, third, and fourth wells over several years. The contribution of reservoir rock elastic properties to the final recovery rate is obtained based on the production of the third and fourth wells over several years.

8. An evaluation system for assessing the contribution of artificial fractures and formation energy to oil recovery in shale oil, characterized in that, include: 3D Fine Reservoir Geological Model Construction Module: Used to construct a 3D fine reservoir geological model for shale oil platforms; Natural fracture distribution model construction module: used to construct a three-dimensional fine reservoir geological model containing natural fractures based on the three-dimensional fine reservoir geological model; The first single-well production acquisition module is used to load artificial fractures into a three-dimensional fine reservoir geological model containing natural fractures, assign values ​​to the conductivity of artificial fractures, obtain a matrix-fracture model, and obtain the first single-well production based on the matrix-fracture model. The second single-well production acquisition module is used to assign values ​​to the fracturing fluid elastic properties of the matrix-fracture model and obtain the second single-well production based on the matrix-fracture model after assigning the fracturing fluid elastic properties. The third single-well production acquisition module is used to assign reservoir fluid elastic properties to the matrix-fracture model after assigning fracturing fluid elastic properties, and to acquire the third single-well production based on the matrix-fracture model after assigning reservoir fluid elastic properties. The fourth single-well production acquisition module is used to assign reservoir rock elastic properties to the matrix-fracture model after assigning reservoir fluid elastic properties, and to acquire the production of the fourth single well based on the matrix-fracture model after assigning reservoir rock elastic properties. Contribution Rate Acquisition Module: Used to acquire the production output of the first, second, third, and fourth wells at different production times, and to acquire the contribution of artificial fractures and formation energy to shale oil production and ultimate recovery rate based on the production output of the first, second, third, and fourth wells at different production times.

9. An electronic device, comprising: A processor; a memory, an electronic device for storing computer program instructions; characterized in that, when executing the computer program, it implements the steps of the evaluation method for obtaining the contribution of artificial fractures and formation energy to the recovery rate of shale oil as described in any one of claims 1-7.

10. A storage medium storing computer program instructions, characterized in that, When the computer program instructions are loaded and run by the processor, the processor executes the evaluation method for obtaining the contribution of artificial fractures and formation energy to the recovery rate of shale oil, as described in any one of claims 1-7.

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