Method, device, electronic device and medium for determining the perfection degree of injection-production well pattern

Abstract

A method, device, electronic device and medium for determining the perfection degree of an injection-production well pattern are disclosed. The method may include: constructing a geological model; determining a calculation formula for flow potential change; and determining the perfection degree of the injection-production well pattern by calculating the flow potential change. Based on three-dimensional geological modeling, on the basis of the flow potential simulation method, by using numerical simulation calculation and image processing means, the present invention obtains the changes of the flow field and saturation field of a fracture-cavity reservoir under different geological backgrounds, calculates the control and utilization degrees of the injection-production well pattern of the fracture-cavity reservoir, and lays a foundation for the quantitative evaluation of well pattern perfection.

Description

Technical Field

[0001] The present invention relates to the field of reservoir engineering, and more specifically, to a method, device, electronic device and medium for determining the perfection degree of an injection-production well pattern. Background Art

[0002] The Ordovician reservoir in Tahe Oilfield has three important characteristics: high-angle fractures are well developed; solution caves, especially large solution caves, are well developed and are the main high-quality reservoir spaces; the development status of fractures and caves gradually deteriorates from top to bottom, and there are relatively dense sections with varying thicknesses, complex distributions and different degrees of development traversed by fractures between the reservoir and the water area (bottom water). Although there are many difficulties in the development of fractured-vuggy reservoirs, through pilot injection, mild water injection and large-scale promotion of various water injection methods in the later stage, the development effect of fractured-vuggy units has been improved. The injection-production well pattern design is the basis for the water injection development of fractured-vuggy reservoirs. It is found in the well pattern design that there are great differences in the geological characteristics and water injection development effects between fractured-vuggy reservoirs and clastic rock reservoirs, and the design concepts and methods of injection-production well patterns are completely different.

[0003] It is found in the design and practice of injection-production well patterns for fractured-vuggy reservoirs that under different geological backgrounds, the fracture-vug structures are different, and the development effects of injection-production well patterns vary greatly, and the well pattern control and utilization degrees are completely different, which greatly affects the popularization of water injection development technology. The reason is that most of the calculation methods for water drive control and utilization degree of injection-production well patterns suitable for clastic rock reservoirs are not applicable in most cases. Even the calculation methods using the evaluation indexes of sandstone reservoirs have obtained wrong results, and it is impossible to form a popularizable and replicable injection-production well pattern design technology for fractured-vuggy reservoirs. With the popularization of large-scale water injection technology, there is an urgent need to establish a calculation method for water drive control and utilization degree suitable for injection-production well patterns of fractured-vuggy reservoirs.

[0004] For the water drive control degree of a well pattern, the water drive control degree of a clastic rock reservoir refers to the ratio of the reserves within the oil-bearing area that can be swept by the injected water under the existing injection-production well pattern conditions to the total developed geological reserves of the reservoir. The water drive control degree is a reflection of the volume sweep coefficient of the injected water. Its size is not only affected by geological factors, but also affected by artificial control factors such as well layout. It is usually simplified as: the ratio of the effective thickness opened by the production wells connected to the injection wells to the total effective thickness opened by the production wells in the well group. This definition believes that as long as the thickness connected between the injection well and the production well is opened, this effective thickness has been controlled. For the reservoir layers not connected between the injection well and the production well, they are classified as the reservoir range where water drive does not exist. According to the definition, the mathematical expression of the water drive control degree is: Rc = h / H, where: Rc is the water drive reserve control degree, %; h is the effective thickness opened by the production wells connected to the injection wells, m; H is the total effective thickness opened by the production wells, m.

[0005] In carbonate reservoirs, since the main reservoir spaces are discrete fractures and caves, fractures and caves are both reservoir spaces and flow channels, the matrix has little reservoir property, and the separability between reservoir bodies is very strong. The original concept of defining the control degree based on thickness is no longer applicable, and it is necessary to reconstruct the definition of well pattern control degree suitable for fractured-vuggy reservoirs.

[0006] Currently, the existing definitions of waterflooded reserve control degree for carbonate fractured-vuggy reservoirs include the following:

[0007] Ratio of injection wells to production wells: The ratio of injection wells to production wells in a unit. This index mainly describes the influence of the injection-production well pattern on the waterflooding development effect horizontally. This calculation method only considers artificial control factors such as well pattern density and does not consider the reservoir geology.

[0008] Ratio of fracture-vug control volume: The ratio of the sum of fracture-vug volumes in the associated well groups of the drilled wells to the total fracture-vug volume. That is, within the same associated well group, it is the ratio of the geological reserves within the spatial range with a relatively small well spacing (generally less than 500 m) from the injection well or a relatively large well spacing but proven to be connected to the geological reserves.

[0009] Ratio of half well spacing area: The injection well draws a circle with a radius of half of the injection-production well spacing, and the production well draws a circle with a radius of one-third of the injection-production well spacing, and they are connected by tangents. The area within the tangents is the waterflood control range, and its reserves are the waterflood control reserves. This method only considers the single-well control degree of injection-production wells, that is, it is considered that a certain area before the injection-production wells is the waterflood reserve control degree, while ignoring the complex connectivity within the injection-production unit.

[0010] Ratio of well control coefficient: For carbonate reservoirs with discrete fractures and caves as the main reservoir spaces, fractures and caves are both reservoir spaces and flow channels, and the matrix has little reservoir property. The formula of the well control coefficient proposed by Liu Huiqing introduces the concept of the spatial configuration relationship between injection-production wells and the fracture-vug network to describe and analyze and measure the control of the injection-production well pattern on the reservoir, which is more in line with the characteristics and geological understanding of Tahe fractured-vuggy reservoirs.

[0011] For the water drive utilization degree of the well pattern, the water drive utilization degree of clastic rock reservoirs refers to the ratio of water drive utilized reserves to the geological reserves of the reservoir, generally expressed as a percentage. In the oil field, the estimation method of waterflood reserve utilization degree usually refers to the ratio of the total water absorption thickness of all tested injection wells to the total connected thickness of injection wells or the ratio of the total liquid production thickness to the total opened thickness of production wells on an annual basis. The mathematical expression is: Rp = hi / Hi or Rp = ho / Ho, where hi and ho are the total water absorption thickness of injection wells and the total liquid production thickness of production wells, m; Hi and Ho are the total connected thickness of injection wells and production wells, m. The concept of water drive utilization degree includes three definitions:

[0012] ① Thickness ratio: According to the definition, it is considered that as long as the oil layer produces fluid or absorbs water, all the reserves are fully utilized, and the degree of waterflood reserve utilization is calculated based on the volume of water injection profile data of water wells and fluid production profile data of oil wells.

[0013] ② Reserve ratio: The method of the type-C waterflood characteristic curve is selected to obtain the waterflooded reserves, and then the degree of waterflood utilization is obtained. The applicable range is the water injection and oil displacement stage after water breakthrough. The mathematical expression is:

[0014]

[0015] Lp Cumulative liquid production, 10,000 tons; Np Cumulative oil production, 10,000 tons; The coefficient B is the reciprocal of the waterflooded reserves.

[0016] First, for conventional sandstone reservoirs, the evaluation indexes of the perfection degree of injection-production well patterns are the control degree and the utilization degree of injection-production well patterns. The determination methods include:

[0017] (1) Numerical simulation calculation method: Using the geological modeling results and production dynamic data, based on the production history matching, calculate the longitudinal water injection thickness of the injection well and the corresponding production layer thickness of the oil well. The ratio of the production layer thickness of the oil well to the water injection layer thickness is the control degree, and the control degree of the injection-production well pattern is obtained after weighting; The longitudinal waterflooded thickness of the injection well and the corresponding waterflooded thickness of the oil well, the ratio of the waterflooded thickness of the oil well to the waterflooded thickness of the water well is used to obtain the control degree, and the utilization degree of the injection-production well pattern is obtained after weighting.

[0018] (2) Reservoir engineering calculation method: Using the classical seepage mechanics and reservoir engineering calculation theories, establish the waterflooding diagrams of different types of injection-production well patterns for regular well patterns, load the actual waterflood characteristic curves, calculate the development indexes of the well patterns, and obtain the control and utilization degrees of the injection-production well patterns.

[0019] (3) Reservoir monitoring method: According to the production logging and processing and interpretation results, analyze the waterflooded thickness of oil and water wells longitudinally, and calculate the control and utilization degrees at different times in segments by means of the definition of the control and utilization degrees of the injection-production well pattern with the numerical simulation method.

[0020] Secondly, for fractured-vuggy reservoirs, there are certain problems with the original calculation methods for the well pattern control degree and utilization degree of clastic rock oil and gas reservoirs because the reservoir types and distributions of carbonate fractured-vuggy reservoirs and clastic rock reservoirs are completely different:

[0021] The first is that the longitudinal layering of fractured-vuggy reservoirs is poor, and they are often distributed in the form of layers with a thickness of dozens of meters to hundreds of meters. There is no strict one-to-one corresponding distribution relationship between the connected layers between injection wells and production wells. Therefore, the original definition of the control degree in clastic rock reservoirs is not applicable;

[0022] Second, even within the same interval, the main controlling factors for the connectivity between karst caves are the distribution characteristics of reservoir lithology, karst dynamics and karst geological characteristics, and the properties of dissolution fluids. As a direct result, there is a high probability of separation between karst caves in the reservoir of fracture-vuggy oil reservoirs.

[0023] Third, during the drilling process of fracture-vuggy reservoirs, the number of karst caves connected is very limited. To achieve communication between most karst caves, artificial acid fracturing measures are often required. The fracture initiation azimuth, fracture extension direction, and fracture extension degree of acid fracturing are mainly controlled by the stress field and the scale of acid fracturing. Thus, it is very difficult to determine and ensure that the karst caves connected within the reservoir belong to the same interval of the same reservoir body.

[0024] Fourth, the calculation of the well pattern control and production degree based on pressure wave propagation only considers the range affected by the driving pressure, which is a planar concept. It cannot consider the differences in control and flow degree caused by gravity differences in the vertical direction. Therefore, a new method is needed that can simultaneously consider the effects of driving pressure and gravity and obtain three-dimensional results in both the cross-section and the plane.

[0025] Due to the above reasons, the intervals between injection and production wells in fracture-vuggy oil reservoirs do not have a strict corresponding relationship. Therefore, the method of using the longitudinal control thickness ratio of intervals as the only calculation parameter to obtain the control degree of the injection-production well pattern is questionable. Moreover, since the control degree exists in both the vertical and planar aspects, which belongs to the category of three-dimensional geometric definitions, it is obvious that there are significant differences between the definition method of the injection-production well pattern control degree in clastic rock reservoirs and this concept. As a direct result, it is impossible to obtain intuitive adjustment countermeasures. For continuously distributed clastic rocks, this problem basically grasps the main contradiction, but for fracture-vuggy oil reservoirs, the problem caused by vertical heterogeneity is not the main contradiction, but the heterogeneity caused by the difference in connectivity between karst caves.

[0026] Therefore, it is necessary to develop a method, device, electronic equipment, and medium for determining the perfection degree of the injection-production well pattern in fracture-vuggy oil reservoirs.

[0027] The information disclosed in the background art section of the present invention is only intended to deepen the understanding of the general background art of the present invention and should not be regarded as an admission or any form of implication that this information constitutes the prior art known to those skilled in the art. Summary of the Invention

[0028] The present invention proposes a method, device, electronic equipment, and medium for determining the perfection degree of an injection-production well pattern. Based on three-dimensional geological modeling and the flow potential simulation method, by using numerical simulation calculations and image processing means, the changes in the flow field and saturation field of fracture-vuggy oil reservoirs under different geological backgrounds are obtained, and the control and production degrees of the injection-production well pattern in fracture-vuggy oil reservoirs are calculated, laying a foundation for the quantitative evaluation of well pattern perfection.

[0029] In a first aspect, an embodiment of the present disclosure provides a method for determining the perfection degree of an injection-production well pattern, including:

[0030] Construct a geological model;

[0031] Determine the calculation formula for the flow potential change;

[0032] Determine the perfection degree of the injection-production well pattern by calculating the flow potential change.

[0033] Preferably, the calculation formula for the flow potential change is:

[0034]

[0035] Wherein, Φ is the flow potential change, Z is the distance from the research point to the reference plane, ρ is the fluid density, and P is the formation pressure of the research point.

[0036] Preferably, the perfection degree of the injection-production well pattern includes the control degree and the utilization degree of the injection-production well pattern.

[0037] Preferably, calculating the control degree of the injection-production well pattern includes:

[0038] Determine the flow potential distribution image through numerical simulation;

[0039] Perform binarization processing on the flow potential distribution image to obtain a flow potential grayscale image;

[0040] Change the well pattern flow potential until the gray level change amount of the flow potential grayscale image is less than the set threshold, and determine the control degree of the injection-production well pattern.

[0041] Preferably, calculating the utilization degree of the injection-production well pattern includes:

[0042] Determine the flow field distribution image through numerical simulation;

[0043] Perform binarization processing on the flow field distribution image to obtain a flow field grayscale image;

[0044] Change the well pattern saturation field until the gray level change amount of the flow field grayscale image is less than the set threshold, and determine the utilization degree of the injection-production well pattern.

[0045] As a specific implementation manner of the embodiment of the present disclosure,

[0046] In a second aspect, an embodiment of the present disclosure further provides a device for determining the perfection degree of an injection-production well pattern, including:

[0047] A construction module that constructs a geological model;

[0048] A calculation module that determines the calculation formula for the flow potential change;

[0049] A determination module determines the perfection degree of an injection-production well pattern by calculating the change in flow potential.

[0050] Preferably, the calculation formula for the change in flow potential is:

[0051]

[0052] where Φ is the change in flow potential, Z is the distance from the research point to the reference plane, ρ is the fluid density, and P is the formation pressure at the research point.

[0053] Preferably, the perfection degree of the injection-production well pattern includes the control degree and the utilization degree of the injection-production well pattern.

[0054] Preferably, calculating the control degree of the injection-production well pattern includes:

[0055] Determining the flow potential distribution image through numerical simulation;

[0056] Performing binarization processing on the flow potential distribution image to obtain a flow potential grayscale image;

[0057] Changing the well pattern flow potential until the change in grayscale of the flow potential grayscale image is less than a set threshold to determine the control degree of the injection-production well pattern.

[0058] Preferably, calculating the utilization degree of the injection-production well pattern includes:

[0059] Determining the flow field distribution image through numerical simulation;

[0060] Performing binarization processing on the flow field distribution image to obtain a flow field grayscale image;

[0061] Changing the well pattern saturation field until the change in grayscale of the flow field grayscale image is less than a set threshold to determine the utilization degree of the injection-production well pattern.

[0062] In a third aspect, an embodiment of the present disclosure further provides an electronic device, which includes:

[0063] A memory storing executable instructions;

[0064] A processor that runs the executable instructions in the memory to implement the method for determining the perfection degree of the injection-production well pattern.

[0065] In a fourth aspect, an embodiment of the present disclosure further provides a computer-readable storage medium, which stores a computer program, and when the computer program is executed by a processor, it implements the method for determining the perfection degree of the injection-production well pattern.

[0066] The beneficial effects are as follows:

[0067] (1) Considering the actual geological conditions and development history of the fracture-vug reservoir, it has guiding significance for the field. Since the actual reservoir geological model is adopted and the calculation process fully simulates the oilfield development history, its results have strong guiding significance for improving the water injection development effect of the fracture-vug reservoir.

[0068] (2) The calculation results are displayed in images, with intuitive results, providing quantitative basis for measures such as infilling production and injection wells, improving injection-production well patterns, converting production wells to injection wells, and adjusting water injection in the later stage of the reservoir. Therefore, it is more convenient and effective to use.

[0069] The methods and apparatuses of the present invention have other characteristics and advantages, which will be apparent from the accompanying drawings incorporated herein and the subsequent detailed description, or will be described in detail in the accompanying drawings incorporated herein and the subsequent detailed description. These accompanying drawings and detailed description are used together to explain the specific principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] By describing the exemplary embodiments of the present invention in more detail in conjunction with the accompanying drawings, the above and other objects, features, and advantages of the present invention will become more apparent. In the exemplary embodiments of the present invention, the same reference numerals generally represent the same components.

[0071] Figure 1 The flowchart showing the steps of the method for determining the perfection degree of an injection-production well pattern according to an embodiment of the present invention is shown.

[0072] Figure 2 The schematic diagram showing the change of the flow potential field with different formation pressure drop amplitudes in the weathered crust karst geological background according to an embodiment of the present invention is shown.

[0073] Figure 3 The schematic diagram showing the change of the saturation field with different formation pressure drop amplitudes in the weathered crust karst geological background according to an embodiment of the present invention is shown.

[0074] Figure 4 The schematic diagram showing the planar sweep degree of the flow potential with different formation pressure drop amplitudes in the weathered crust karst geological background according to an embodiment of the present invention is shown.

[0075] Figure 5 The schematic diagram showing the vertical sweep degree of the flow potential with different formation pressure drop amplitudes in the weathered crust karst geological background according to an embodiment of the present invention is shown.

[0076] Figure 6 The schematic diagram showing the planar sweep degree of the saturation with different formation pressure drop amplitudes in the weathered crust karst geological background according to an embodiment of the present invention is shown.

[0077] Figure 7Schematic diagram showing the vertical sweep extent of saturation with different formation pressure drop amplitudes in the weathered crust karst geological background according to an embodiment of the present invention.

[0078] Figure 8 Schematic diagram showing the variation of the pressure field with different formation pressure drop amplitudes in the ancient underground river karst geological background according to an embodiment of the present invention.

[0079] Figure 9 Schematic diagram showing the variation of the saturation field with different formation pressure drop amplitudes in the ancient underground river karst geological background according to an embodiment of the present invention.

[0080] Figure 10 Schematic diagram showing the planar sweep extent of flow potential with different formation pressure drop amplitudes in the ancient underground river karst geological background according to an embodiment of the present invention.

[0081] Figure 11 Schematic diagram showing the vertical sweep extent of flow potential with different formation pressure drop amplitudes in the ancient underground river karst geological background according to an embodiment of the present invention.

[0082] Figure 12 Schematic diagram showing the planar sweep extent of saturation with different formation pressure drop amplitudes in the ancient underground river karst geological background according to an embodiment of the present invention.

[0083] Figure 13 Schematic diagram showing the vertical sweep extent of saturation with different formation pressure drop amplitudes in the ancient underground river karst geological background according to an embodiment of the present invention.

[0084] Figure 14 Schematic diagram showing the variation of the flow potential field with different formation pressure drop amplitudes in the fault-karst body geological background according to an embodiment of the present invention.

[0085] Figure 15 Schematic diagram showing the variation of the saturation field with different formation pressure drop amplitudes in the fault-karst body geological background according to an embodiment of the present invention.

[0086] Figure 16 Schematic diagram showing the planar sweep extent of flow potential with different formation pressure drop amplitudes in the fault-karst body geological background according to an embodiment of the present invention.

[0087] Figure 17 Schematic diagram showing the vertical sweep extent of flow potential with different formation pressure drop amplitudes in the fault-karst body geological background according to an embodiment of the present invention.

[0088] Figure 18 Schematic diagram showing the planar sweep extent of saturation with different formation pressure drop amplitudes in the fault-karst body geological background according to an embodiment of the present invention.

[0089] Figure 19 Schematic diagram showing the vertical sweep degree of saturation with different formation pressure drop amplitudes in the background of fracture-vug karst geology according to an embodiment of the present invention.

[0090] Figure 20 Block diagram showing a device for determining the perfection degree of an injection-production well pattern according to an embodiment of the present invention.

[0091] Explanation of reference numerals:

[0092] 201, construction module; 202, calculation module; 203, determination module. Detailed implementation manners

[0093] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein.

[0094] The present invention provides a method for determining the perfection degree of an injection-production well pattern, including:

[0095] Constructing a geological model.

[0096] Specifically, according to the amount of reconstructed data, the reconstruction methods are divided into sparse reconstruction, semi-dense reconstruction, and dense reconstruction. For fracture-vug reservoirs, semi-dense reconstruction is adopted in the present invention.

[0097] Determining a calculation formula for the change in flow potential; in one example, the calculation formula for the change in flow potential is:

[0098]

[0099] Wherein, Φ is the change in flow potential, Z is the distance from the research point to the reference plane, ρ is the fluid density, and P is the formation pressure at the research point.

[0100] Specifically, through static and dynamic analysis of reservoir fluid flow, a conceptual model of the hydrodynamic field in the study area is established, the change in fluid potential at different development stages is calculated, and the formation process, preservation conditions, movement laws, and distribution laws of oil, gas, and water in the study area are clarified.

[0101] The movement speed, movement direction, movement laws, and movement characteristics of groundwater are mainly restricted by the magnitude and distribution of fluid potential. Fluid potential is a comprehensive index of gravity, pressure, velocity, and fluid interfacial tension. This index can effectively depict the movement trend of underground fluids and determine the migration directions, paths, and accumulation and dispersion sections of gas and water. Under hydrodynamic action, the migration direction of fluid flow cannot be simply indicated by the buoyancy direction or the structural contour direction. Only by calculating the fluid potential can it be determined. For any fluid molecule in a water-bearing complex, the magnitude of its potential energy can be calculated by the following formula:

[0102]

[0103] In the formula, Z represents the distance from the research point to the reference plane. When the reference plane is selected as the sediment surface of a certain period, Z is the paleo-burial depth, ρ is the fluid density, p is the formation pressure at the research point, u is the fluid velocity, б is the fluid interface tension, θ is the wetting angle, and γ is the capillary radius.

[0104] The first term on the right side of the formula is the position potential energy, the second term is the pressure potential energy, the third term is the fluid kinetic potential energy, and the fourth term is the interfacial potential energy. Since the groundwater flow in oil and gas reservoirs is extremely slow, its kinetic potential energy can be ignored, and the interfacial potential energy is much smaller than the pressure potential energy and the position potential energy. Therefore, the calculation of the fluid potential can be simplified to formula (1).

[0105] By calculating the change in fluid potential, the perfection degree of the injection-production well pattern is determined. In one example, the perfection degree of the injection-production well pattern includes the control degree and the utilization degree of the injection-production well pattern.

[0106] In one example, calculating the control degree of the injection-production well pattern includes: determining the fluid potential distribution image through numerical simulation; performing binary processing on the fluid potential distribution image to obtain the fluid potential grayscale image; changing the well pattern fluid potential until the change in grayscale of the fluid potential grayscale image is less than the set threshold, and determining the control degree of the injection-production well pattern.

[0107] In one example, calculating the utilization degree of the injection-production well pattern includes: determining the flow field distribution image through numerical simulation; performing binary processing on the flow field distribution image to obtain the flow field grayscale image; changing the well pattern saturation field until the change in grayscale of the flow field grayscale image is less than the set threshold, and determining the utilization degree of the injection-production well pattern.

[0108] Specifically, the proportion of the area that the fluid potential of the injection-production well pattern can reach in the area involved by the injection-production well pattern includes two directions: vertical and planar. The area involved by the injection-production well pattern is the area composed of half of the well spacing. The area that the fluid potential reaches is called the control area of the injection-production well pattern. The ratio of this area to the area involved by the injection-production well pattern is the control degree of the injection-production well pattern. Binary processing is performed on the pressure field obtained by numerical simulation, that is, the fluid potential distribution image, to form a fluid potential grayscale image. Using image processing methods, by changing the injection pressure, injection medium, injection-production speed, etc., the well pattern fluid potential is changed, and the changes in different fluid potential change areas and the control degree of the well pattern are calculated until the change in grayscale of the fluid potential grayscale image is less than the set threshold. The vertical and planar sweep degrees of the final pressure field are calculated, and the product of the two sweep degrees is used as the final control degree of the injection-production well pattern to evaluate the well pattern control degree.

[0109] The proportion of the area that the streamline of the injection-production well pattern can reach in the area involved by the injection-production well pattern also includes two directions: vertical and horizontal. The area involved by the injection-production well pattern is the area composed of half of the well spacing. The area reached by the streamline is the swept area. The ratio of the area of this region to the area of the region involved by the injection-production well pattern is the utilization degree of the injection-production well pattern. Binarize the saturation field, i.e., the flow field distribution image obtained by numerical simulation, to form a grayscale flow field image. Using image processing methods, change the well pattern saturation field by changing the injection pressure, injection medium, injection-production rate, etc., and calculate the changes in different flow potential change regions and the utilization degree of the well pattern until the grayscale change of the grayscale flow field image is less than the set threshold. Calculate the vertical and horizontal sweep degrees of the final saturation field, and the product of the two sweep degrees is used as the final utilization degree of the injection-production well pattern to evaluate the utilization degree of the well pattern.

[0110] Use the well pattern control and utilization degree of the fractured-vuggy reservoir obtained above as the evaluation index for the perfection degree of the injection-production well pattern. Obviously, the control degree and utilization degree of the injection-production well pattern in the fractured-vuggy reservoir are related to items such as well pattern type, well pattern parameters, injection-production parameters, injected fluid properties, development stage, and development method. Improving the control degree of the injection-production well pattern in the fractured-vuggy reservoir is the main goal of well pattern design, and obtaining a higher utilization degree of the injection-production well pattern is the basis for achieving a higher recovery rate.

[0111] The present invention also provides a device for determining the perfection degree of an injection-production well pattern, including:

[0112] A construction module that constructs a geological model.

[0113] Specifically, according to the amount of reconstructed data, the reconstruction method is divided into sparse reconstruction, semi-dense reconstruction, and dense reconstruction. For the fractured-vuggy reservoir, the present invention adopts semi-dense reconstruction.

[0114] A calculation module that determines the calculation formula for flow potential change; in one example, the calculation formula for flow potential change is:

[0115]

[0116] Where Φ is the flow potential change, Z is the distance from the research point to the reference plane, ρ is the fluid density, and P is the formation pressure at the research point.

[0117] Specifically, through static and dynamic analysis of reservoir fluid flow, establish a conceptual model of the hydrodynamic field in the study area, calculate the fluid potential changes in different development periods, and clarify the formation process, preservation conditions, movement laws, and distribution laws of oil, gas, and water in the study area.

[0118] The velocity, direction, laws, and characteristics of groundwater movement are mainly controlled by the magnitude and distribution of fluid potential. Fluid potential is a comprehensive index of gravity, pressure, velocity, and fluid interfacial tension. This index can effectively describe the movement trend of underground fluids and determine the migration direction, path, and accumulation and dispersion sections of gas and water. Under hydrodynamic action, the flow direction of the liquid cannot be simply indicated by the buoyancy direction or the structural contour direction. It can only be determined by calculating the fluid potential. The potential energy of any fluid molecule in an aquifer complex can be calculated using formula (2). Since the groundwater flow in oil and gas reservoirs is extremely slow, its movement potential energy can be ignored, and the interfacial potential energy is much smaller than the pressure potential energy and the positional potential energy. Therefore, the calculation of fluid potential can be simplified to formula (1).

[0119] A determination module determines the perfection degree of the injection-production well pattern by calculating the change in flow potential. In one example, the perfection degree of the injection-production well pattern includes the control degree and the utilization degree of the injection-production well pattern.

[0120] In one example, calculating the control degree of the injection-production well pattern includes: determining the flow potential distribution image through numerical simulation; performing binarization processing on the flow potential distribution image to obtain a flow potential grayscale image; changing the well pattern flow potential until the change in grayscale of the flow potential grayscale image is less than a set threshold to determine the control degree of the injection-production well pattern.

[0121] In one example, calculating the utilization degree of the injection-production well pattern includes: determining the flow field distribution image through numerical simulation; performing binarization processing on the flow field distribution image to obtain a flow field grayscale image; changing the well pattern saturation field until the change in grayscale of the flow field grayscale image is less than a set threshold to determine the utilization degree of the injection-production well pattern.

[0122] Specifically, the proportion of the area that the flow potential of the injection-production well pattern can cover in the area involved by the injection-production well pattern includes two directions: longitudinal and planar. The area involved by the injection-production well pattern is the area composed of half of the well spacing. The area covered by the flow potential is called the control area of the injection-production well pattern. The ratio of this area to the area involved by the injection-production well pattern is the control degree of the injection-production well pattern. Binarize the pressure field, i.e., the flow potential distribution image, obtained through numerical simulation to form a flow potential grayscale image. Using image processing methods, change the well pattern flow potential by changing the injection pressure, injection medium, injection-production speed, etc., calculate the changes in different flow potential change areas and the control degree of the well pattern, until the grayscale change of the flow potential grayscale image is less than the set threshold, calculate the final longitudinal and planar coverage degrees of the pressure field, and the product of the two coverage degrees is used as the final control degree of the injection-production well pattern to evaluate the control degree of the well pattern.

[0123] The proportion of the area that the streamline of the injection-production well pattern can reach in the area involved by the injection-production well pattern also includes two directions: vertical and horizontal. The area involved by the injection-production well pattern is the area composed of half of the well spacing, and the area reached by the streamline is the swept area. The ratio of the area of this area to the area of the area involved by the injection-production well pattern is the utilization degree of the injection-production well pattern. Binary processing is performed on the saturation field, i.e., the flow field distribution image, obtained by numerical simulation to form a gray-scale image of the flow field. Using image processing methods, by changing the injection pressure, injection medium, injection-production rate, etc., the saturation field of the well pattern is changed, and the changes in different flow potential change regions and the utilization degree of the well pattern are calculated until the gray-scale change of the gray-scale image of the flow field is less than the set threshold. The vertical and horizontal sweep degrees of the final saturation field are calculated, and the product of the two sweep degrees is used as the final utilization degree of the injection-production well pattern to evaluate the utilization degree of the well pattern.

[0124] The well pattern control and utilization degree of the fracture-cavity reservoir obtained above are used as the evaluation indexes for the perfection degree of the injection-production well pattern. Obviously, the control degree and utilization degree of the injection-production well pattern in the fracture-cavity reservoir are related to items such as well pattern type, well pattern parameters, injection-production parameters, injection fluid properties, development stage, development method, etc. Improving the control degree of the injection-production well pattern in the fracture-cavity reservoir is the main goal of well pattern design, and obtaining a higher utilization degree of the injection-production well pattern is the basis for obtaining a higher recovery rate.

[0125] The present invention also provides an electronic device, which includes: a memory storing executable instructions; a processor that runs the executable instructions in the memory to implement the above-mentioned method for determining the perfection degree of the injection-production well pattern.

[0126] The present invention also provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it implements the above-mentioned method for determining the perfection degree of the injection-production well pattern.

[0127] To facilitate the understanding of the solution and its effects of the embodiments of the present invention, the following gives four specific application examples. Those skilled in the art should understand that this example is only for facilitating the understanding of the present invention, and any specific details are not intended to limit the present invention in any way.

[0128] Example 1

[0129] Figure 1 The flowchart showing the steps of the method for determining the perfection degree of the injection-production well pattern according to an embodiment of the present invention is shown.

[0130] As Figure 1 shown, the method for determining the perfection degree of the injection-production well pattern includes: Step 101, constructing a geological model; Step 102, determining the calculation formula for flow potential change; Step 103, determining the perfection degree of the injection-production well pattern by calculating the flow potential change.

[0131] Figure 2 Schematic diagram showing the variation of the flow potential field with different formation pressure decline amplitudes in the weathered crust karst geological background according to an embodiment of the present invention.

[0132] Figure 3 Schematic diagram showing the variation of the saturation field with different formation pressure decline amplitudes in the weathered crust karst geological background according to an embodiment of the present invention.

[0133] Based on the variation results of the pressure field and saturation field of the fracture-cavity unit in the weathered crust karst geological background obtained from the numerical simulation calculation results, the maximum change values of pressure and saturation in the plane and profile can be statistically obtained, and the product of the two maximum values is calculated as the control and utilization degree of the well pattern. Based on this, different well pattern control and utilization degrees are evaluated.

[0134] Figure 4 Schematic diagram showing the planar sweep extent of the flow potential with different formation pressure drop amplitudes in the weathered crust karst geological background according to an embodiment of the present invention.

[0135] Figure 5 Schematic diagram showing the vertical sweep extent of the flow potential with different formation pressure drop amplitudes in the weathered crust karst geological background according to an embodiment of the present invention.

[0136] The maximum planar control degree of the fracture-cavity unit in the weathered crust karst geological background is 68.4%, and the maximum vertical control degree is 93.2%. Then the maximum control degree of the well pattern is 63.7%.

[0137] Figure 6 Schematic diagram showing the planar sweep extent of the saturation with different formation pressure drop amplitudes in the weathered crust karst geological background according to an embodiment of the present invention.

[0138] Figure 7 Schematic diagram showing the vertical sweep extent of the saturation with different formation pressure drop amplitudes in the weathered crust karst geological background according to an embodiment of the present invention.

[0139] The maximum planar utilization degree of the fracture-cavity unit in the weathered crust karst geological background is 48.3%, and the maximum vertical utilization degree is 66.1%. Then the maximum utilization degree of the well pattern is 31.9%.

[0140] Figure 8 Schematic diagram showing the variation of the pressure field with different formation pressure decline amplitudes in the paleo-underground river karst geological background according to an embodiment of the present invention.

[0141] Figure 9 Schematic diagram showing the variation of the saturation field with different formation pressure decline amplitudes in the paleo-underground river karst geological background according to an embodiment of the present invention.

[0142] Based on the variation results of the pressure field and saturation field of the fracture-cavity unit in the ancient underground river karst geological background obtained from numerical simulation calculations, the maximum variation values of pressure and saturation in the plane and profile can be statistically obtained, and the product of the two maximum values is calculated as the control and utilization degree of the well pattern. Based on this, the control and utilization degrees of different well patterns are evaluated.

[0143] Figure 10 The schematic diagram shows the plane sweep degree of flow potential with different formation pressure drop amplitudes in the ancient underground river karst geological background according to an embodiment of the present invention.

[0144] Figure 11 The schematic diagram shows the vertical sweep degree of flow potential with different formation pressure drop amplitudes in the ancient underground river karst geological background according to an embodiment of the present invention.

[0145] The maximum plane control degree of the fracture-cavity unit in the ancient underground river karst geological background is 73.3%, and the maximum vertical control degree is 41.2%. Then the maximum control degree of the well pattern is 30.2%.

[0146] Figure 12 The schematic diagram shows the plane sweep degree of saturation with different formation pressure drop amplitudes in the ancient underground river karst geological background according to an embodiment of the present invention.

[0147] Figure 13 The schematic diagram shows the vertical sweep degree of saturation with different formation pressure drop amplitudes in the ancient underground river karst geological background according to an embodiment of the present invention.

[0148] The maximum plane utilization degree of the fracture-cavity unit in the ancient underground river karst geological background is 47.7%, and the maximum vertical utilization degree is 36.9%. Then the maximum utilization degree of the well pattern is 17.6%.

[0149] Figure 14 The schematic diagram shows the variation of the flow potential field with different formation pressure drop amplitudes in the fault-karst geological background according to an embodiment of the present invention.

[0150] Figure 15 The schematic diagram shows the variation of the saturation field with different formation pressure drop amplitudes in the fault-karst geological background according to an embodiment of the present invention.

[0151] Based on the variation results of the pressure field and saturation field of the fracture-cavity unit in the fault-karst geological background obtained from numerical simulation calculations, the maximum variation values of pressure and saturation in the plane and profile can be statistically obtained, and the product of the two maximum values is calculated as the control and utilization degree of the well pattern. Based on this, the control and utilization degrees of different well patterns are evaluated.

[0152] Figure 16Shows a schematic diagram of the plane wavefront degree of pressure drop amplitude in different strata and the flow potential in a fault-karst geological background according to an embodiment of the present invention.

[0153] Figure 17 Shows a schematic diagram of the vertical wavefront degree of pressure drop amplitude in different strata and the flow potential in a fault-karst geological background according to an embodiment of the present invention.

[0154] The maximum plane control degree of the fracture-cavity unit in the fault-karst geological background is 40.9%, and the maximum vertical control degree is 79.6%. Then the maximum control degree of the well pattern is 32.6%.

[0155] Figure 18 Shows a schematic diagram of the plane wavefront degree of saturation with different formation pressure drop amplitudes in a fault-karst geological background according to an embodiment of the present invention.

[0156] Figure 19 Shows a schematic diagram of the vertical wavefront degree of saturation with different formation pressure drop amplitudes in a fault-karst geological background according to an embodiment of the present invention.

[0157] The maximum plane utilization degree of the fracture-cavity unit in the fault-karst geological background is 25.3%, and the maximum vertical utilization degree is 81.1%. Then the maximum utilization degree of the well pattern is 20.5%.

[0158] In summary, due to the good connectivity of the weathered crust unit, the control degree and utilization degree of the well pattern are the highest. The paleo-underground river and fault-karst units have strong heterogeneity, and the control degree and utilization degree of the well pattern are also low. Therefore, the potential for late-stage treatment of the fracture-cavity units of the paleo-underground river and fault-karst is large, and the treatment effect will be good.

[0159] Example 2

[0160] Figure 20 Shows a block diagram of a device for determining the perfection degree of an injection-production well pattern according to an embodiment of the present invention.

[0161] As Figure 20 shown, the device for determining the perfection degree of the injection-production well pattern includes:

[0162] A construction module 201 for constructing a geological model;

[0163] A calculation module 202 for determining a flow potential change calculation formula;

[0164] A determination module 203 for determining the perfection degree of the injection-production well pattern by calculating the flow potential change.

[0165] As an optional solution, the flow potential change calculation formula is:

[0166]

[0167] Among them, Φ is the change in flow potential, Z is the distance from the research point to the reference plane, ρ is the fluid density, and P is the formation pressure at the research point.

[0168] As an alternative, the perfection degree of the injection-production well pattern includes the control degree and the utilization degree of the injection-production well pattern.

[0169] As an alternative, calculating the control degree of the injection-production well pattern includes:

[0170] Determine the flow potential distribution image through numerical simulation;

[0171] Perform binarization processing on the flow potential distribution image to obtain a flow potential grayscale image;

[0172] Change the well pattern flow potential until the gray level change amount of the flow potential grayscale image is less than the set threshold value to determine the control degree of the injection-production well pattern.

[0173] As an alternative, calculating the utilization degree of the injection-production well pattern includes:

[0174] Determine the flow field distribution image through numerical simulation;

[0175] Perform binarization processing on the flow field distribution image to obtain a flow field grayscale image;

[0176] Change the well pattern saturation field until the gray level change amount of the flow field grayscale image is less than the set threshold value to determine the utilization degree of the injection-production well pattern.

[0177] Example 3

[0178] The present disclosure provides an electronic device, which includes: a memory storing executable instructions; a processor that runs the executable instructions in the memory to implement the above method for determining the perfection degree of the injection-production well pattern.

[0179] The electronic device according to an embodiment of the present disclosure includes a memory and a processor.

[0180] The memory is used to store non-temporary computer-readable instructions. Specifically, the memory may include one or more computer program products, and the computer program products may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, random access memory (RAM) and / or cache memory, etc. The non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, etc.

[0181] The processor may be a central processing unit (CPU) or other forms of processing units with data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device to perform desired functions. In an embodiment of the present disclosure, the processor is used to run the computer-readable instructions stored in the memory.

[0182] Those skilled in the art should understand that, in order to solve the technical problem of how to obtain good user experience effects, well-known structures such as communication buses and interfaces may also be included in this embodiment, and these well-known structures should also be included in the protection scope of the present disclosure.

[0183] For a detailed description of this embodiment, reference may be made to the corresponding descriptions in the foregoing embodiments, and details will not be repeated here.

[0184] Example 4

[0185] An embodiment of the present disclosure provides a computer-readable storage medium storing a computer program, and when the computer program is executed by a processor, the method for determining the perfection degree of an injection-production well pattern is implemented.

[0186] According to the computer-readable storage medium of the embodiment of the present disclosure, non-transitory computer-readable instructions are stored thereon. When the non-transitory computer-readable instructions are run by a processor, all or part of the steps of the methods of the foregoing embodiments of the present disclosure are executed.

[0187] The above-mentioned computer-readable storage media include, but are not limited to: optical storage media (e.g., CD-ROM and DVD), magneto-optical storage media (e.g., MO), magnetic storage media (e.g., magnetic tape or removable hard disk), media with built-in rewritable non-volatile memory (e.g., memory card), and media with built-in ROM (e.g., ROM cartridge).

[0188] Those skilled in the art should understand that the purpose of the above description of the embodiments of the present invention is only to exemplarily illustrate the beneficial effects of the embodiments of the present invention, and is not intended to limit the embodiments of the present invention to any example given.

[0189] The above has described the embodiments of the present invention. The above description is exemplary and not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A method for determining the perfection degree of an injection-production well pattern, characterized in that, including: Constructing a geological model; Determining the calculation formula for the change in flow potential; Determining the perfection degree of the injection-production well pattern by calculating the change in flow potential; wherein, the calculation formula for the change in flow potential is: where Φ is the change in flow potential, Z is the distance from the research point to the reference plane, ρ is the fluid density, and P is the formation pressure at the research point; wherein, the perfection degree of the injection-production well pattern includes the control degree and the utilization degree of the injection-production well pattern; wherein, calculating the control degree of the injection-production well pattern includes: Determining the flow potential distribution image through numerical simulation; Performing binarization processing on the flow potential distribution image to obtain a flow potential grayscale image; Changing the well pattern flow potential until the change in grayscale of the flow potential grayscale image is less than the set threshold, and determining the control degree of the injection-production well pattern; wherein, calculating the utilization degree of the injection-production well pattern includes: Determining the flow field distribution image through numerical simulation; Performing binarization processing on the flow field distribution image to obtain a flow field grayscale image; Changing the well pattern saturation field until the change in grayscale of the flow field grayscale image is less than the set threshold, and determining the utilization degree of the injection-production well pattern.

2. A device for determining the perfection degree of an injection-production well pattern, characterized in that including: A construction module for constructing a geological model; A calculation module for determining the calculation formula for the change in flow potential; A determination module for determining the perfection degree of the injection-production well pattern by calculating the change in flow potential; wherein, the calculation formula for the change in flow potential is: where Φ is the change in flow potential, Z is the distance from the research point to the reference plane, ρ is the fluid density, and P is the formation pressure at the research point; wherein, the perfection degree of the injection-production well pattern includes the control degree and the utilization degree of the injection-production well pattern; wherein, calculating the control degree of the injection-production well pattern includes: Determining the flow potential distribution image through numerical simulation; Performing binarization processing on the flow potential distribution image to obtain a flow potential grayscale image; Changing the well pattern flow potential until the change in grayscale of the flow potential grayscale image is less than the set threshold, and determining the control degree of the injection-production well pattern; wherein, calculating the utilization degree of the injection-production well pattern includes: Determining the flow field distribution image through numerical simulation; Performing binarization processing on the flow field distribution image to obtain a flow field grayscale image; Changing the well pattern saturation field until the change in grayscale of the flow field grayscale image is less than the set threshold, and determining the utilization degree of the injection-production well pattern.

3. An electronic device, characterized in that, The electronic device includes: A memory storing executable instructions; A processor that runs the executable instructions in the memory to implement the method for determining the perfection degree of the injection-production well pattern according to claim 1.

4. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, it implements the method for determining the perfection degree of the injection-production well pattern according to claim 1.

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