Artificial joint-based seismic geology combined unconventional reservoir method, system, device and medium

Abstract

The application discloses a kind of based on artificial seam seismic geology combined unconventional reservoir method, system, device and medium, comprising: using the well logging data of inspection well and development well, construction is fractured reservoir permeability fitting formula;Based on the reservoir permeability fitting formula after fracturing, the permeability after fracturing of development well target layer is obtained;Based on three-dimensional seismic inversion and the permeability after fracturing of target layer, the reservoir thickness and permeability data volume of target layer are obtained;The reservoir thickness and permeability data volume predicted by earthquake are input into geological model, and the final geological model is obtained.The application can add the influence of artificial seam to geological model, can effectively improve geological model precision, provide reliable basic data for subsequent numerical simulation, improve remaining oil prediction precision.

Description

Technical Field

[0001] This invention belongs to the field of reservoir development technology and relates to a method, system, device and medium for seismic-geological integration of unconventional reservoirs based on artificial fractures. Background Technology

[0002] Currently, most oilfield development has entered the mid-to-late stages, and secondary development of oilfields has been put on the agenda. A key aspect of secondary development is predicting remaining oil. The most widely used method is reservoir numerical simulation. A common characteristic of unconventional reservoir development, such as low-permeability, ultra-low-permeability, and tight oil reservoirs, is the need for reservoir fracturing. Therefore, incorporating the influence of artificial fractures into the geological model is crucial for improving the model's accuracy, providing reliable basic data for subsequent numerical simulations, enhancing the accuracy of remaining oil prediction, and supporting secondary development of oilfields. This is a key technical challenge facing the secondary development of unconventional oilfields. Summary of the Invention

[0003] The purpose of this invention is to solve the problems in the prior art and provide a seismic-geological combined method, system, device and medium based on artificial fractures for unconventional reservoirs. This method can incorporate the influence of artificial fractures into the geological model, effectively improve the accuracy of the geological model, provide reliable basic data for subsequent numerical simulations, and improve the accuracy of remaining oil prediction.

[0004] To achieve the above objectives, the present invention employs the following technical solution:

[0005] A seismic-geological joint modeling method for unconventional reservoirs based on artificial fractures includes:

[0006] Using logging data from inspection wells and development wells, a fitting formula for reservoir permeability after fracturing is constructed;

[0007] Based on the reservoir permeability fitting formula after fracturing, the permeability of the target layer in the development well after fracturing is obtained.

[0008] Based on 3D seismic inversion and permeability after fracturing of the target layer, the reservoir thickness and permeability data of the target layer are obtained.

[0009] The reservoir thickness and permeability data predicted by earthquakes are input into the geological model to obtain the final geological model.

[0010] A further improvement of the present invention is that:

[0011] The logging data from inspection wells and development wells are used specifically as follows: full-wave logging and coring are performed on inspection wells to obtain the permeability values ​​of the reservoirs that are not flooded; the logging data from development wells is used to obtain the permeability values ​​of the original reservoirs.

[0012] A fitting formula for reservoir permeability after fracturing is constructed by inputting the permeability values ​​of the original reservoir and the reservoir that was not flooded into the simulation software for fitting, thereby obtaining the fitting formula for reservoir permeability after fracturing.

[0013] Based on 3D seismic inversion and permeability after fracturing of the target layer, the reservoir thickness and permeability data volume of the target layer are obtained. Specifically, well-seismic calibration is performed through synthetic records, and the target layer is interpreted by stratigraphic tracking. A 3D seismic model is established based on well logging lithology and converted permeability. Seismic inversion is performed under the constraints of the 3D seismic model to obtain the reservoir thickness and permeability data volume of the target layer.

[0014] The geological model is a three-dimensional quantitative stochastic model, which includes information on stratigraphic undulation characteristics, faults, lithology, porosity, permeability, and oil saturation.

[0015] A seismic-geological joint unconventional reservoir modeling system based on artificial fractures includes:

[0016] The module constructs a fitting formula for reservoir permeability after fracturing using logging data from inspection wells and development wells.

[0017] The first acquisition module obtains the permeability of the target layer of the development well after fracturing based on the reservoir permeability fitting formula after fracturing.

[0018] The second acquisition module acquires reservoir thickness and permeability data of the target layer based on three-dimensional seismic inversion and permeability after fracturing of the target layer.

[0019] The third acquisition model is used to input the reservoir thickness and permeability data predicted by earthquakes into the geological model to obtain the final geological model.

[0020] A terminal device includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the method described above.

[0021] A computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the above-described method.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] This invention, based on the formula for calculating the permeability of fracturing reservoirs and using reservoir thickness and permeability data obtained through seismic inversion, realizes a geological model based on artificial fractures. This combined technology utilizes 3D seismic data and inspection well data acquired after development to establish a formula for calculating the permeability of fracturing reservoirs. Furthermore, it uses seismic inversion to obtain the longitudinal and lateral distribution characteristics of the permeability of fracturing reservoirs, thus converting the impact of artificial fractures on the reservoir into permeability data and incorporating it into the geological model. This invention effectively improves the accuracy of the geological model by adding the influence of artificial fractures to the geological model, providing reliable basic data for subsequent numerical simulations and improving the accuracy of remaining oil prediction. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a flowchart of the seismic-geological combined unconventional reservoir method based on artificial fractures according to an embodiment of the present invention;

[0026] Figure 2 This is a structural diagram of an unconventional reservoir system based on artificial fractures, combining seismic and geological methods, according to an embodiment of the present invention.

[0027] Figure 3 This is a graph showing the regression formula for reservoir permeability after fracturing in an embodiment of the present invention.

[0028] Figure 4 This is a profile of the sand body thickness obtained by seismic waveform inversion according to an embodiment of the present invention;

[0029] Figure 5 This is a seismic waveform-indicating inversion permeability profile according to an embodiment of the present invention;

[0030] Figure 6 This is a comparison chart of the initial fitted curves;

[0031] Figure 7 This is a map showing the distribution of oil saturation (remaining oil) predicted by combined seismic and geological data in the study area; where 'a' represents the length of 81... 21 Oil saturation distribution diagram, b is a length of 8 12 2 Oil saturation distribution diagram, c is the length 81 2 Oil saturation distribution map;

[0032] Figure 8 For the research area director 81 2 Oil saturation diagram;

[0033] Figure 9 For the research area director 81 2 Oil saturation diagram and drilling steerable diagram of XC1 horizontal well. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0035] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0036] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0037] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0038] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0039] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0040] The present invention will now be described in further detail with reference to the accompanying drawings:

[0041] See Figure 1 This invention discloses a seismic-geological joint modeling method for unconventional oil reservoirs based on artificial fractures, comprising:

[0042] S101. Using logging data from inspection wells and development wells, a fitting formula for reservoir permeability after fracturing is constructed.

[0043] The logging data from inspection wells and development wells are used specifically as follows: full-wave logging and coring are performed on inspection wells to obtain the permeability values ​​of the reservoirs that are not flooded; the logging data from development wells is used to obtain the permeability values ​​of the original reservoirs.

[0044] A fitting formula for reservoir permeability after fracturing is constructed by inputting the permeability values ​​of the original reservoir and the reservoir that was not flooded into the simulation software for fitting, thereby obtaining the fitting formula for reservoir permeability after fracturing.

[0045] S102, based on the reservoir permeability fitting formula after fracturing, obtains the permeability of the target layer in the development well after fracturing.

[0046] S103, based on 3D seismic inversion and permeability after fracturing of the target layer, obtains reservoir thickness and permeability data of the target layer.

[0047] Well-seismic calibration is performed using synthetic records, and stratigraphic interpretation is conducted for the target layer. A three-dimensional seismic model is established based on well logging lithology and converted permeability. Seismic inversion is performed under the constraints of the three-dimensional seismic model to obtain the reservoir thickness and permeability data of the target layer.

[0048] In this example, the 3D seismic data acquired after the oilfield development shows a good correlation between reservoir properties and target layer amplitude. Strong reflections from the target layer indicate poor reservoir properties, while weak reflections indicate good reservoir properties. Therefore, reservoir permeability and thickness can be obtained by using 3D seismic waveform indices for inversion.

[0049] S104: Input the reservoir thickness and permeability data predicted by the earthquake into the geological model to obtain the final geological model.

[0050] Geological models are the foundation of reservoir numerical simulation. A geological model is a three-dimensional quantitative stochastic model generated using computer graphics technology, based on a comprehensive analysis of geological, well logging, geophysical data and various interpretation results or conceptual models. This model reflects the underground strata to a certain extent and usually includes information such as strata undulation characteristics, faults, lithology, porosity, permeability, and oil saturation.

[0051] See Figure 2 This invention discloses a seismic-geological joint unconventional reservoir modeling system based on artificial fractures, comprising:

[0052] The module constructs a fitting formula for reservoir permeability after fracturing using logging data from inspection wells and development wells.

[0053] The first acquisition module obtains the permeability of the target layer of the development well after fracturing based on the reservoir permeability fitting formula after fracturing.

[0054] The second acquisition module acquires reservoir thickness and permeability data of the target layer based on three-dimensional seismic inversion and permeability after fracturing of the target layer.

[0055] The third acquisition model is used to input the reservoir thickness and permeability data predicted by earthquakes into the geological model to obtain the final geological model.

[0056] A formula for calculating post-compression reservoir permeability was established using inspection wells. To study oilfield development, inspection wells were drilled in the development area, and full-wavelength logging and coring were performed. Regression was conducted using permeability data from the same sub-layer as the development wells, as shown in Table 1.

[0057] Table 1: Permeability of 7 sub-layers in development wells and inspection wells

[0058] Sub-layer number Average permeability of development wells (mD) Average permeability of inspection wells (mD) 1 0.33 0.36 2 0.40 0.69 3 0.49 0.84 4 0.59 1.03 5 0.71 1.20 6 0.82 1.46 7 1.02 2.13

[0059] See Figure 3 A formula for calculating reservoir permeability after fracturing is established. The formula for calculating reservoir permeability after fracturing is as follows:

[0060] Y = 2.1384X - 0.3414 (1)

[0061] In the formula, X is the permeability value of the target layer of the development well, which is the permeability value of the reservoir before fracturing, and Y is the permeability value of the target layer of the inspection well, which is the permeability value of the reservoir after fracturing.

[0062] The permeability obtained from the well site was converted into the permeability after fracturing using formula (1). The permeability of the target formation in 174 development wells in the work area was converted into the permeability after fracturing using formula (1).

[0063] Using 3D seismic data, the reservoir thickness and permeability data of the target layer were obtained through inversion. This was the first 3D seismic acquisition in the study area after 10 years of development. Using the acquired wide-azimuth 3D seismic data, with an aspect ratio of 1 for the target layer, waveform indication inversion technology was employed to invert the permeability and reservoir thickness of the target layer. The inversion results show that they can effectively reflect the variations in reservoir thickness and permeability between wells. The single sand body thickness of the target layer in this area is 5-11 m, and the permeability is 0.4-1.8 mD. Verification by eight test wells shows that the average absolute error of the sand body thickness is between 0.36-0.89 m, and the absolute error of the permeability is between 0.02-0.04 mD. (See [link to relevant documentation]). Figure 4 , Figure 5 The target reservoir and permeability volume are obtained, and geological modeling is performed. See [link / reference] Figure 6 The initial fitting curves for five modeling methods are shown. 1 represents the model established using the permeability formula to convert well logging data and seismic inversion; 2 represents monthly oil production observations; 3 represents the model established using the permeability formula to convert well logging data; 4 represents the model established using development well logging data; and 5 represents the model established using development well logging interpretation and seismic fracture analysis. Figure 6 As can be seen, the initial fit of this invention is the highest, at 65.77%. See also... Figure 7 Where a is a length of 81 21 Oil saturation distribution diagram, b is a length of 8 12 2 Oil saturation distribution diagram, c is the length 81 2 The oil saturation distribution map shows that areas with higher oil saturation are richer in remaining oil. Using this geological model, numerical simulations are conducted to predict the planar distribution characteristics of the remaining oil.

[0064] See Figure 8 As per Table 1, 11 wells were drilled in this area in 2019. Numerical simulation results were used for verification, and 10 wells were found to be compatible, resulting in a compatibility rate of 90.9%. Wells with an oil saturation greater than 55% indicated abundant remaining oil, those with an oil saturation of 45%-55% also indicated significant remaining oil, and those with an oil saturation less than 45% indicated relatively little remaining oil. Based on the prediction results of this invention, two short horizontal wells are provided, one of which, XC1, has been completed. (See [reference]). Figure 9 As can be seen from the oil saturation diagram, the remaining oil in the horizontal section is relatively rich. The horizontal section of the well is 155m long, the sand layer drilling rate is 100%, and the oil layer drilling rate is 84.5%, which is in good agreement with the numerical simulation prediction results. The well is ready for oil testing.

[0065] Table 2. Sidetracking data for the study area in 2019

[0066]

[0067]

[0068] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A seismic-geological combined unconventional reservoir modeling method based on artificial fractures, characterized in that, include: Using logging data from inspection wells and development wells, a fitting formula for reservoir permeability after fracturing is constructed; Based on the reservoir permeability fitting formula after fracturing, the permeability of the target layer in the development well after fracturing is obtained. Based on 3D seismic inversion and permeability after fracturing of the target layer, the reservoir thickness and permeability data of the target layer are obtained. The reservoir thickness and permeability data predicted by earthquakes are input into the geological model to obtain the final geological model. The use of logging data from inspection wells and development wells specifically involves: performing full-wavelength logging and coring on inspection wells to obtain the permeability value of the reservoir that was not flooded; and using logging data from development wells to obtain the permeability value of the original reservoir. The process of constructing the reservoir permeability fitting formula after fracturing is as follows: input the permeability value of the original reservoir and the permeability value of the reservoir that was not flooded into the simulation software for fitting, and obtain the reservoir permeability fitting formula after fracturing. The process involves obtaining reservoir thickness and permeability data of the target layer based on 3D seismic inversion and permeability after fracturing. Specifically, this includes: performing well-seismic calibration using synthetic logging records and interpreting the stratigraphic sequence of the target layer; establishing a 3D seismic model based on well logging lithology and converted permeability; and performing seismic inversion under the constraints of the 3D seismic model to obtain reservoir thickness and permeability data of the target layer.

2. The seismic-geological combined unconventional reservoir modeling method based on artificial fractures according to claim 1, characterized in that, The geological model is a three-dimensional quantitative stochastic model, which includes information on stratigraphic undulation characteristics, faults, lithology, porosity, permeability, and oil saturation.

3. A seismic-geological joint unconventional reservoir modeling system based on artificial fractures, characterized in that: include: The module constructs a fitting formula for reservoir permeability after fracturing using logging data from inspection wells and development wells. The first acquisition module obtains the permeability of the target layer of the development well after fracturing based on the reservoir permeability fitting formula after fracturing. The second acquisition module acquires reservoir thickness and permeability data of the target layer based on three-dimensional seismic inversion and permeability after fracturing of the target layer. The third acquisition model is used to input the reservoir thickness and permeability data predicted by the earthquake into the geological model to obtain the final geological model. The use of logging data from inspection wells and development wells specifically involves: performing full-wavelength logging and coring on inspection wells to obtain the permeability value of the reservoir that was not flooded; and using logging data from development wells to obtain the permeability value of the original reservoir. The process of constructing the reservoir permeability fitting formula after fracturing is as follows: input the permeability value of the original reservoir and the permeability value of the reservoir that was not flooded into the simulation software for fitting, and obtain the reservoir permeability fitting formula after fracturing. The process involves obtaining reservoir thickness and permeability data of the target layer based on 3D seismic inversion and permeability after fracturing. Specifically, this includes: performing well-seismic calibration using synthetic logging records and interpreting the stratigraphic sequence of the target layer; establishing a 3D seismic model based on well logging lithology and converted permeability; and performing seismic inversion under the constraints of the 3D seismic model to obtain reservoir thickness and permeability data of the target layer.

4. A terminal device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method as described in any one of claims 1-2.

5. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method as described in any one of claims 1-2.

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