Tight sandstone gas reservoir horizontal well volume fracturing fracture characteristic parameter obtaining method and device and storage medium

Abstract

The invention discloses a tight sandstone gas reservoir horizontal well volume fracturing fracture characteristic parameter obtaining method and device and a storage medium. The method comprises the following steps that S10, the change relation of the pumping pressure, the displacement and the sand ratio along with time is obtained based on a fracturing construction curve; and S20, the effectiveness of fracturing construction is judged. And S30, geological parameters, well completion parameters and construction parameters of a fracturing implementation well are obtained, and a horizontal well fracturing geological model, a stress field model and a wellbore model are established. And S40, fracturing pump injection program parameters are input based on the fracturing construction bulletin. And S50, on the basis of the geological parameters, the well completion parameters and the construction parameters, fracturing crack characteristic parameters are solved. With the adoption of the method, the form and characteristic parameters of the fracturing crack can be obtained after the field fracturing construction is finished, so that a support is provided for evaluating the fracturing yield increasing effect.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of oil and gas field development, and particularly relates to a method for obtaining fracture characteristic parameters of volume fracturing of a horizontal well in a tight sandstone gas reservoir. BACKGROUND

[0002] China is rich in tight sandstone gas resources, and the tight gas represented by the Upper Triassic Xujiahe Formation and the Jurassic Shaximiao Formation is the most realistic and important position for increasing reserves and production of natural gas on a large scale. With the focus on the development of tight gas, the development technology system has gradually matured. In order to solve the difficulty of realizing large-scale commercial production caused by low pore pressure, low porosity and low permeability of tight reservoirs, hydraulic fracturing stimulation technology is introduced, and remarkable results have been achieved in field construction.

[0003] The fractures formed by fracturing are high-speed channels for the seepage of oil and gas from the formation to the wellbore, and the stimulation effect of hydraulic fracturing depends largely on the effect of the fractures after fracturing. In the evaluation method of the stimulation effect after fracturing, the reservoir stimulation effect is evaluated through test production, production pressure difference, and test analysis data, and such evaluation methods can only evaluate the fracturing effect after the oil test is completed, and the cycle of obtaining evaluation data is long and the time is long.

[0004] At present, it is an urgent problem for those skilled in the art to provide an efficient fracturing fracture parameter obtaining method. SUMMARY

[0005] The purpose of the present application is to quantitatively characterize the fracture morphology and characteristic parameters, and to provide a method for obtaining fracture characteristic parameters of volume fracturing of a horizontal well in a tight sandstone gas reservoir from the perspective of fracturing engineering parameters. The fracture morphology and characteristic parameters can be obtained after the field fracturing construction is completed, thereby providing support for the evaluation of the stimulation effect of fracturing.

[0006] To achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0007] A method for obtaining fracture characteristic parameters of volume fracturing of a horizontal well in a tight sandstone gas reservoir, comprising the following steps:

[0008] Step S10: obtaining the relationship between pump pressure, displacement and sand ratio changing with time based on the fracturing construction curve.

[0009] Step S20: judging the effectiveness of fracturing construction.

[0010] Step S30: obtaining fracturing implementation well geology parameters, completion parameters and construction parameters, and establishing a horizontal well fracturing geology model, a stress field model and a wellbore model.

[0011] Step S40: inputting fracturing pump injection program parameters based on the fracturing construction bulletin.

[0012] Step S50, based on the geological parameters, completion parameters, construction parameters, solve the fracture characteristics parameters.

[0013] Further, the fracturing construction effectiveness judgment in step S20 is based on:

[0014] The change relationship between pump pressure and displacement in the preflush stage is used to judge the formation breaking point: the pump pressure rapidly decreases, and the displacement increases; the pump pressure is constant, and the displacement increases; the displacement is constant, and the pump pressure rapidly decreases after rising.

[0015] The change relationship between the sand-carrying liquid volume, pump pressure and displacement in the sand-carrying liquid stage is used to judge the fracture extension: the pump pressure shows a steady trend when the displacement is constant, indicating that the fracture extends normally; the pump pressure suddenly rises when the displacement is constant, indicating that the fracture may encounter a high stress zone or a natural fracture zone during the extension process, which hinders the extension of the fracture; the pump pressure suddenly decreases when the displacement is constant, indicating that the fracture may encounter a large fracture zone or a high filtration zone during the extension process, which affects the fracture fluid fracturing efficiency.

[0016] The two are combined to judge the fracturing effectiveness.

[0017] Further, the obtaining of the geological parameters of the fracturing well in step S30 includes: gas reservoir temperature, pressure, porosity, permeability, water saturation, reservoir thickness, rock compression coefficient, geological stratification depth, stress, stress gradient, Young's modulus, Poisson's ratio, fracture toughness, filtration coefficient.

[0018] The completion parameters include: well structure parameters, perforation position, perforation number, perforation diameter.

[0019] The fracturing construction parameters include: fracturing fluid type and performance, proppant type and performance.

[0020] Further, the fracturing pump injection program parameters in step S40 include: sand-carrying liquid volume, proppant concentration, displacement, pump injection time, and well material type.

[0021] Further, the solving of the fracturing fracture characteristic parameters in step S50 is based on computer simulation, and the simulation software is used to invert the fracturing construction process.

[0022] Further, the fracturing fracture characteristic parameters in step S50 include: fracture length, fracture width, flow conductivity, and reservoir reconstruction volume.

[0023] The application also provides a computer device, which comprises a processor and a memory, and the memory stores a computer program, and the processor implements the above-mentioned measurement method when executing the computer program.

[0024] The application further provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the method.

[0025] In summary, compared with the prior art, the application has at least the following beneficial effects:

[0026] The application determines fracturing effectiveness based on fracturing operation curves, and establishes a method for obtaining fracture characteristic parameters based on fracture inversion simulation, to solve fracture length, fracture width, fracture conductivity, and reservoir reconstruction volume, and other fracture characteristic parameters such as fracture height and proppant placement concentration can also be solved according to needs. The method can intuitively and quantitatively evaluate fractures, and provide a certain reference for fracturing fracture effect evaluation and operation parameter optimization of a horizontal well in a tight sandstone gas reservoir. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 The figure is a flow chart of the application.

[0028] Figure 2 The figure is a fracturing operation curve diagram of the embodiment of the application.

[0029] Figure 3 The figure is a schematic diagram of fracture width of an inversion simulation cluster fracture of the embodiment of the application.

[0030] Figure 4 The figure is a schematic diagram of fracture conductivity of an inversion simulation cluster fracture of the embodiment of the application.

[0031] Figure 5 The figure is a schematic diagram of a shut-in fracture profile / support profile of an inversion simulation of the embodiment of the application.

[0032] Figure 6 The figure is a schematic diagram of a fracture morphology in a post-fracturing section of an inversion simulation of the embodiment of the application. DETAILED DESCRIPTION

[0033] The application will be further described in detail below in combination with embodiments and specific implementation manners. However, it should not be understood that the scope of the above-mentioned subject matter of the application is limited to the following embodiments, and any technology realized based on the content of the application belongs to the scope of the application.

[0034] In the description of the application, it should be understood that the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the application and simplify the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application.

[0035] As Figure 1 shown, a method for obtaining fracture characteristic parameters of a horizontal well volume fracturing in a tight sand gas reservoir, comprising the following steps:

[0036] Step S10, obtaining the relationship between pump pressure, displacement and sand ratio with time based on fracturing operation curve Figure 2 ).

[0037] Step S20, judging the effectiveness of fracturing operation.

[0038] Step S30, obtaining fracturing implementation well geology parameters, completion parameters and operation parameters, using reservoir numerical simulation software to establish horizontal well fracturing geology model, stress field model and wellbore model.

[0039] The fracturing implementation well geology parameters include: gas reservoir temperature, pressure, porosity, permeability, water saturation, reservoir thickness, rock compressibility, geology stratification depth, stress, stress gradient, Young's modulus, Poisson's ratio, fracture toughness and filtration coefficient.

[0040] The completion parameters include: wellbore structure parameters, perforation position, perforation number and perforation diameter.

[0041] The operation parameters include: fracturing fluid type and performance, and proppant type and performance.

[0042] Step S40, inputting fracturing pump injection program parameters based on fracturing operation bulletin.

[0043] The fracturing pump injection program parameters include: sand-carrying liquid volume, proppant concentration, displacement, pump injection time and well material type of each stage.

[0044] Step S50, solving fracturing fracture characteristic parameters based on geology parameters, completion parameters and operation parameters. The solving of fracturing fracture characteristic parameters is based on computer simulation, and the simulation software is used to inverse fracturing operation process. The inverse simulation fracture shape schematic diagram is shown in Figures 3-6 , wherein the fracturing fracture characteristic parameters include fracture length, fracture width and conductivity, and the solving results of reservoir reconstruction volume (SRV) are shown in Table 1.

[0045] Table 1: Solving results of fracture characteristic parameters of each section of Wenqian XX well after fracturing

[0046]

[0047]

[0048]

[0049] The application further provides a computer device, comprising a processor and a memory, wherein the memory stores a computer program, and the processor implements the method when executing the computer program.

[0050] The application further provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the method.

[0051] Those skilled in the art can understand that the above-mentioned embodiments are specific examples for implementing the application, and various changes can be made in form and details in practical application without departing from the spirit and scope of the application.

Claims

1. A method for obtaining fracture characteristic parameters of volume fracturing of a horizontal well in a tight sand gas reservoir, characterized in that, It comprises the following steps: Step S10, obtaining the relationship between pump pressure, displacement, and sand ratio changing with time based on fracturing operation curve; Step S20, judging fracturing operation effectiveness; Step S30, obtaining fracturing implementation well geology parameters, completion parameters, and operation parameters, establishing horizontal well fracturing geology model, stress field model, and wellbore model; Step S40, inputting fracturing pump injection program parameters based on fracturing operation bulletin; Step S50, solving fracturing fracture characteristic parameters based on geology parameters, completion parameters, and operation parameters.

2. The method of claim 1, wherein, The basis for judging fracturing operation effectiveness in step S20 is as follows: In preflush stage, the relationship between pump pressure and displacement is used to judge formation breakdown point: pump pressure rapidly drops, and displacement rises; pump pressure remains unchanged, and displacement rises; displacement remains unchanged, and pump pressure rises and then rapidly drops; In sand-carrying fluid stage, the relationship between sand injection amount, pump pressure, and displacement is used to judge fracture extension: pump pressure shows a steady trend when displacement is constant, indicating normal fracture extension; pump pressure suddenly rises when displacement is constant, indicating that the fracture may encounter high stress zone or natural fracture zone during extension, hindering the extension of the fracture; pump pressure suddenly drops when displacement is constant, indicating that the fracture may encounter large fracture zone or high filtration zone during extension, affecting the fracture forming efficiency of fracturing fluid; Both are combined to judge fracturing effectiveness.

3. The method of claim 1, wherein, The obtaining of fracturing implementation well geology parameters in step S30 comprises gas reservoir temperature, pressure, porosity, permeability, water saturation, reservoir thickness, rock compressibility, geology stratification depth, stress, stress gradient, Young's modulus, Poisson's ratio, fracture toughness, and filtration coefficient.

4. A method as claimed in claim 1, characterized in that In step S30, completion parameters comprise wellbore structure parameters, perforation position, perforation number, and perforation diameter.

5. The method of claim 1, wherein, In S30, fracturing operation parameters comprise fracturing fluid type and performance, and proppant type and performance.

6. The method of claim 1, wherein, In step S40, the fracturing pump injection program parameters comprise sand-carrying fluid volume, proppant concentration, displacement, pump injection time, and well material type in each stage.

7. The method of claim 1, wherein, The solving of fracturing fracture characteristic parameters in step S50 is based on computer simulation and uses simulation software to inverse fracturing operation process.

8. The method of claim 1, wherein, The fracturing fracture characteristic parameters in step S50 comprise fracture length, fracture width, conductivity, and reservoir reconstruction volume. 9.A computer device, comprising a processor and a memory, wherein the memory has stored thereon a computer program, and the computer device is characterized in that, The processor executes the computer program to realize the method in any one of claims 1-8.

10. A computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to realize the method in any one of claims 1-8.

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