Method and device for determining petroleum migration state of tight sandstone oil reservoir

Abstract

The embodiment of the invention provides a method and device for determining the petroleum migration state of tight sandstone oil accumulation, and relates to the technical field of petroleum and natural gas. The method comprises the following steps: acquiring permeability and a plurality of flow velocity and pressure gradient curves of a plurality of sandstone samples; according to the flow velocity and pressure gradient curve, the Reynolds number and friction coefficient calculation formula related to the permeability and the apparent permeability calculation formula, a Reynolds number and friction coefficient curve related to the permeability and an apparent permeability pressure gradient curve are obtained through calculation; and according to the permeability, the permeability-related Reynolds number friction coefficient curve and the apparent permeability pressure gradient curve, constructing a migration flow state change chart. According to the method, the migration flow state change plate is constructed, and the plate displays three areas where petroleum cannot be migrated, nonlinearly migrated and linearly migrated in the sandstone sample; and determining the migration state of the petroleum in the sandstone sample and the minimum permeability of the petroleum in the sandstone sample through the migration flow state change chart.

Description

Technical Field

[0001] The present application relates to the field of oil and natural gas technology, and in particular to a method and device for determining the oil migration status of tight sandstone oil reservoirs. Background Art

[0002] Tight sandstone reservoirs have complex pore structures and tiny pore throats, which affect oil migration. By studying the migration state and its changing patterns within these reservoirs, we can better understand and predict oil flow behavior, thereby determining the critical pressure conditions and flow regime changes that enable oil migration. This not only helps to reveal the dynamic mechanisms of tight sandstone oil accumulation but also guides exploration and development strategies for tight oil, improving resource utilization efficiency.

[0003] Existing research on oil migration in tight sandstone reservoirs primarily relies on laboratory simulations. High-precision experimental equipment is typically used to measure the oil's initial pressure gradient and seepage characteristics under varying pressure and temperature conditions. During these experiments, by controlling and adjusting experimental parameters such as pore pressure, fluid viscosity, and rock permeability, the oil migration process in tight sandstone is simulated to observe and record the initiation conditions for oil migration.

[0004] However, existing technologies have a problem with determining the state of oil migration. When studying oil migration, existing technologies rely solely on laboratory-measured starting pressure gradients to determine the critical conditions for oil migration. However, due to significant differences between laboratory conditions and actual geological environments, coupled with limitations in experimental precision, determining the state of oil migration remains difficult. Summary of the Invention

[0005] The embodiments of the present application provide a method and apparatus for determining the migration status of oil in tight sandstone oil reservoirs, so as to solve the problem that the prior art cannot determine the migration status of oil.

[0006] In a first aspect, embodiments of the present application provide a method for determining the migration status of oil in tight sandstone oil reservoirs, comprising:

[0007] Obtaining the permeability of a plurality of preset tight sandstone samples and a plurality of flow velocity and pressure gradient curves; wherein the plurality of flow velocity and pressure gradient curves are used to express the relationship between the flow velocity and the pressure gradient of a plurality of water-saturated samples, wherein the plurality of water-saturated samples are obtained by water-saturating the plurality of tight sandstone samples;

[0008] Calculating the permeability-related Reynolds number friction coefficient curves and the apparent permeability pressure gradient curves of the plurality of water-saturated samples according to the plurality of flow rate pressure gradient curves, the preset permeability-related Reynolds number and friction coefficient calculation formula, and the preset apparent permeability calculation formula;

[0009] Establishing a permeability minimum migration pressure gradient curve and a permeability minimum stable migration pressure gradient curve based on the multiple permeabilities, the multiple permeability-related Reynolds number friction coefficient curves, and the multiple apparent permeability pressure gradient curves;

[0010] A migration flow pattern change chart is constructed based on the permeability minimum migration pressure gradient curve and the permeability minimum stable migration pressure gradient curve; wherein, the migration flow pattern change chart is used to display the migration state of oil in the multiple tight sandstone samples, and the migration flow pattern change chart includes a non-migration zone, a nonlinear migration zone and a linear migration zone, and the non-migration zone, the nonlinear migration zone and the linear migration zone refer to the areas where the oil cannot migrate, undergoes nonlinear migration and undergoes linear migration in the multiple tight sandstone samples, respectively.

[0011] In a possible design, obtaining the permeability of a plurality of preset tight sandstone samples and a plurality of flow velocity pressure gradient curves includes:

[0012] Obtaining the plurality of tight sandstone samples and the permeabilities of the plurality of tight sandstone samples; wherein the plurality of tight sandstone samples have different permeabilities, the plurality of tight sandstone samples have different porosities, and the plurality of porosities and the plurality of permeabilities are both less than a preset first threshold;

[0013] performing water saturation treatment on the plurality of tight sandstone samples to obtain the plurality of water-saturated samples;

[0014] An oil migration simulation experiment is performed on the multiple water-saturated samples to obtain flow rate pressure gradient curves of the multiple water-saturated samples.

[0015] In one possible design, establishing a permeability minimum migration pressure gradient curve and a permeability minimum stable migration pressure gradient curve based on the multiple permeabilities, the multiple permeability-related Reynolds number friction coefficient curves, and the multiple apparent permeability pressure gradient curves includes:

[0016] The minimum migration pressure gradient and the minimum stable migration pressure gradient of the plurality of water-saturated samples are calculated based on the plurality of permeability-dependent Reynolds number friction coefficient curves and the plurality of apparent permeability pressure gradient curves; wherein the plurality of minimum migration pressure gradients refer to the gradients required for the oil in the plurality of water-saturated samples to initiate nonlinear migration, and the plurality of minimum stable migration pressure gradients refer to the gradients required for the oil in the plurality of water-saturated samples to transition from nonlinear migration to linear migration;

[0017] The permeability minimum migration pressure gradient curve and the permeability minimum stable migration pressure gradient curve are established according to the multiple permeabilities, the multiple minimum migration pressure gradients, and the multiple minimum stable migration pressure gradients.

[0018] In one possible design, calculating the minimum migration pressure gradient and the minimum stable migration pressure gradient of the plurality of water-saturated samples based on the plurality of permeability-related Reynolds number friction coefficient curves and the plurality of apparent permeability pressure gradient curves includes:

[0019] Performing function fitting based on the multiple apparent permeability pressure gradient curves to obtain multiple apparent permeability pressure gradient formulas;

[0020] Calculating the minimum migration pressure gradient of the plurality of water-saturated samples according to the plurality of apparent permeability pressure gradient formulas;

[0021] The minimum stable migration pressure gradient of the plurality of water-saturated samples is calculated according to the plurality of permeability-related Reynolds number friction coefficient curves, the plurality of apparent permeability pressure gradient formulas, and the plurality of apparent permeability pressure gradient curves.

[0022] In one possible design, the target water-saturated sample is any one of the multiple water-saturated samples, and calculating the minimum stable migration pressure gradient of the multiple water-saturated samples based on the multiple permeability-related Reynolds number friction coefficient curves, the multiple apparent permeability pressure gradient formulas, and the multiple apparent permeability pressure gradient curves includes:

[0023] Calculating a first minimum stable migration pressure gradient of the target water-saturated sample based on a permeability-dependent Reynolds number friction coefficient curve of the target water-saturated sample; wherein the first minimum stable migration pressure gradient refers to a gradient at which oil in the target water-saturated sample transitions from nonlinear migration to linear migration;

[0024] According to the apparent permeability pressure gradient curve of the target water-saturated sample, a second minimum stable migration pressure gradient and a third minimum stable migration pressure gradient of the target water-saturated sample are calculated; wherein, the second minimum stable migration pressure gradient refers to the lowest pressure gradient for maintaining linear migration of oil in the target water-saturated sample, and the third minimum stable migration pressure gradient refers to the minimum pressure gradient in the apparent permeability pressure gradient curve of the target water-saturated sample at which the apparent permeability is lower than a preset second threshold value. The second minimum stable migration pressure gradient is calculated based on the apparent permeability pressure gradient curve, and the third minimum stable migration pressure gradient is calculated based on the apparent permeability change rate pressure gradient curve. The apparent permeability change rate pressure gradient curve is calculated based on the apparent permeability pressure gradient curve;

[0025] The minimum stable migration pressure gradient of the target water-saturated sample is determined according to the first minimum stable migration pressure gradient, the second minimum stable migration pressure gradient, and the third minimum stable migration pressure gradient.

[0026] In a possible design, after constructing the migration flow pattern change map based on the permeability minimum migration pressure gradient curve and the permeability minimum stable migration pressure gradient curve, the method further includes:

[0027] Determining the permeability physical property value of the oil based on the migration flow pattern change chart; wherein the permeability physical property value refers to the lowest permeability value that enables the oil to migrate in the plurality of tight sandstone samples;

[0028] The oil extraction strategy is formulated according to the permeability physical property value.

[0029] In a second aspect, an embodiment of the present application provides a device for determining the migration status of oil in a tight sandstone oil reservoir, the device comprising:

[0030] A preset data acquisition module is used to obtain the permeability of a plurality of preset tight sandstone samples and a plurality of flow velocity and pressure gradient curves; wherein the plurality of flow velocity and pressure gradient curves are used to express the relationship between the flow velocity and the pressure gradient of a plurality of water-saturated samples, and the plurality of water-saturated samples are obtained by water-saturating the plurality of tight sandstone samples;

[0031] a curve calculation module, configured to calculate the permeability-related Reynolds number friction coefficient curves and the apparent permeability pressure gradient curves of the plurality of water-saturated samples based on the plurality of flow rate pressure gradient curves, a preset permeability-related Reynolds number and friction coefficient calculation formula, and a preset apparent permeability calculation formula;

[0032] a curve building module for building a permeability minimum migration pressure gradient curve and a permeability minimum stable migration pressure gradient curve based on the multiple permeabilities, the multiple permeability-related Reynolds number friction coefficient curves, and the multiple apparent permeability pressure gradient curves;

[0033] A map construction module is used to construct a migration flow pattern change map based on the permeability minimum migration pressure gradient curve and the permeability minimum stable migration pressure gradient curve; wherein, the migration flow pattern change map is used to display the migration state of oil in the multiple tight sandstone samples, and the migration flow pattern change map includes a non-migration area, a nonlinear migration area and a linear migration area, and the non-migration area, the nonlinear migration area and the linear migration area refer to the areas where the oil cannot migrate, undergoes nonlinear migration and undergoes linear migration in the multiple tight sandstone samples, respectively.

[0034] In one possible design, the preset data acquisition module includes:

[0035] an acquisition unit, configured to acquire the plurality of tight sandstone samples and the permeabilities of the plurality of tight sandstone samples; wherein the plurality of tight sandstone samples have different permeabilities, the plurality of tight sandstone samples have different porosities, and the plurality of porosities and the plurality of permeabilities are both less than a preset first threshold;

[0036] a water saturation unit, configured to perform water saturation treatment on the plurality of tight sandstone samples to obtain the plurality of water saturated samples;

[0037] The experimental unit is used to perform an oil migration simulation experiment on the multiple water-saturated samples to obtain flow rate pressure gradient curves of the multiple water-saturated samples.

[0038] In one possible design, the curve building module includes:

[0039] a gradient calculation unit, configured to calculate, based on the multiple permeability-related Reynolds number friction coefficient curves and the multiple apparent permeability pressure gradient curves, the minimum migration pressure gradient and the minimum stable migration pressure gradient of the multiple water-saturated samples; wherein the multiple minimum migration pressure gradients refer to the gradients required for the oil in the multiple water-saturated samples to initiate nonlinear migration, and the multiple minimum stable migration pressure gradients refer to the gradients required for the oil in the multiple water-saturated samples to transition from nonlinear migration to linear migration;

[0040] The curve construction unit is used to establish the permeability minimum migration pressure gradient curve and the permeability minimum stable migration pressure gradient curve according to the multiple permeabilities, the multiple minimum migration pressure gradients and the multiple minimum stable migration pressure gradients.

[0041] In one possible design, the gradient calculation unit includes:

[0042] a function fitting device for performing function fitting based on the plurality of apparent permeability pressure gradient curves to obtain a plurality of apparent permeability pressure gradient formulas;

[0043] a calculation device for calculating the minimum migration pressure gradient of the plurality of water-saturated samples according to the plurality of apparent permeability pressure gradient formulas;

[0044] A gradient calculation device is used to calculate the minimum stable migration pressure gradient of the multiple water-saturated samples based on the multiple permeability-related Reynolds number friction coefficient curves, the multiple apparent permeability pressure gradient formulas and the multiple apparent permeability pressure gradient curves.

[0045] In one possible design, the target water-saturated sample is any one of the multiple water-saturated samples, and the gradient calculation device includes:

[0046] a first gradient calculation component for calculating a first minimum stable migration pressure gradient of the target water-saturated sample based on a permeability-dependent Reynolds number friction coefficient curve of the target water-saturated sample; wherein the first minimum stable migration pressure gradient refers to a gradient at which oil in the target water-saturated sample transitions from nonlinear migration to linear migration;

[0047] a second gradient calculation component for calculating a second minimum stable migration pressure gradient and a third minimum stable migration pressure gradient of the target water-saturated sample based on the apparent permeability pressure gradient curve of the target water-saturated sample; wherein the second minimum stable migration pressure gradient refers to the lowest pressure gradient for maintaining linear migration of oil in the target water-saturated sample, and the third minimum stable migration pressure gradient refers to the lowest pressure gradient in the apparent permeability pressure gradient curve of the target water-saturated sample at which the apparent permeability is lower than a preset second threshold value; the second minimum stable migration pressure gradient is calculated based on the apparent permeability pressure gradient curve, and the third minimum stable migration pressure gradient is calculated based on the apparent permeability change rate pressure gradient curve, and the apparent permeability change rate pressure gradient curve is calculated based on the apparent permeability pressure gradient curve;

[0048] A gradient determination component is configured to determine the minimum stable migration pressure gradient of the target water-saturated sample based on the first minimum stable migration pressure gradient, the second minimum stable migration pressure gradient, and the third minimum stable migration pressure gradient.

[0049] In one possible design, the apparatus for determining the oil migration state of tight sandstone oil reservoirs further includes:

[0050] a physical property value determination module, configured to determine the permeability physical property value of the oil based on the migration flow pattern change chart; wherein the permeability physical property value refers to the lowest permeability value that enables the oil to migrate in the plurality of tight sandstone samples;

[0051] A strategy formulation module is used to formulate the oil extraction strategy according to the permeability physical property value.

[0052] In a third aspect, the present application provides an electronic device, comprising: a processor, and a memory communicatively connected to the processor;

[0053] The memory stores computer-executable instructions;

[0054] When the processor executes the computer-executable instructions stored in the memory, it is used to implement the method for determining the petroleum migration status of tight sandstone oil accumulation as described in any one of the first aspects.

[0055] In a fourth aspect, the present application provides a computer-readable storage medium, which stores computer-executable instructions. When the computer-executable instructions are executed by a processor, they are used to implement the method for determining the petroleum migration status of tight sandstone oil reservoirs as described in any one of the first aspects.

[0056] In a fifth aspect, the present application provides a computer program product, comprising a computer program, which, when executed by a processor, is used to implement the method for determining the petroleum migration status of tight sandstone oil reservoirs as described in any one of the first aspects.

[0057] The present application provides a method and device for determining the migration state of oil in tight sandstone oil reservoirs. The method includes: obtaining the permeability and multiple flow velocity pressure gradient curves of multiple preset tight sandstone samples; calculating the permeability-related Reynolds number friction coefficient curves and apparent permeability pressure gradient curves of the multiple water-saturated samples based on the multiple flow velocity pressure gradient curves, preset permeability-related Reynolds number and friction coefficient calculation formulas, and a preset apparent permeability calculation formula; establishing a minimum permeability migration pressure gradient curve and a minimum stable permeability migration pressure gradient curve based on the multiple permeabilities, the multiple permeability-related Reynolds number friction coefficient curves, and the multiple apparent permeability pressure gradient curves; and constructing a migration flow state change map based on the minimum permeability migration pressure gradient curve and the minimum stable permeability migration pressure gradient curve. The method of determining the migration state of oil in tight sandstone oil reservoirs disclosed in the present application obtains multiple velocity pressure gradient curves and the permeability of tight sandstone samples, calculates the permeability-related Reynolds number friction coefficient curve and the apparent permeability pressure gradient curve, and thus establishes the permeability minimum migration pressure gradient curve and the minimum stable migration pressure gradient curve. Finally, a migration flow pattern change chart is constructed, which can intuitively display the migration state of oil in different tight sandstone samples, including non-migration areas, nonlinear migration areas, and linear migration areas. This method solves the problem in the prior art that the migration state of oil is difficult to determine due to the difference between laboratory conditions and the actual geological environment, and provides a solution for accurately judging the migration state of oil in tight sandstone reservoirs. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0059] Figure 1 A schematic diagram of an application scenario of the method for determining the oil migration status of tight sandstone oil reservoirs provided in an embodiment of the present application;

[0060] Figure 2 Schematic diagram of the process of determining the oil migration state of tight sandstone oil reservoirs provided in the embodiment of the present application Figure 1 ;

[0061] Figure 3 A diagram of the migration and flow pattern changes provided in the embodiments of this application;

[0062] Figure 4 A flow rate pressure gradient curve diagram of the water-saturated sample S1 provided in an embodiment of the present application;

[0063] Figure 5 A flow rate and pressure gradient curve of the water-saturated sample S2 provided in an embodiment of the present application;

[0064] Figure 6 A flow rate and pressure gradient curve of the water-saturated sample S3 provided in an embodiment of the present application;

[0065] Figure 7 A flow rate-pressure gradient curve of the water-saturated sample S4 provided in an embodiment of the present application;

[0066] Figure 8 A flow rate-pressure gradient curve of the water-saturated sample S5 provided in an embodiment of the present application;

[0067] Figure 9 Flow rate and pressure gradient curve of the water-saturated sample S6 provided in the embodiment of the present application;

[0068] Figure 10 Flow rate and pressure gradient curve of water-saturated sample S7 provided in an embodiment of the present application;

[0069] Figure 11 A flow rate pressure gradient curve diagram of the water-saturated sample S8 provided in an embodiment of the present application;

[0070] Figure 12 Flow rate and pressure gradient curve of the water-saturated sample S9 provided in the embodiment of the present application;

[0071] Figure 13A flow rate and pressure gradient curve of the water-saturated sample S10 provided in an embodiment of the present application;

[0072] Figure 14 A graph showing the Reynolds number friction coefficient associated with the permeability of the water-saturated sample S1 provided in an embodiment of the present application;

[0073] Figure 15 A graph showing the Reynolds number friction coefficient associated with the permeability of the water-saturated sample S2 provided in an embodiment of the present application;

[0074] Figure 16 A graph showing the Reynolds number friction coefficient associated with the permeability of the water-saturated sample S3 provided in an embodiment of the present application;

[0075] Figure 17 A graph showing the Reynolds number friction coefficient associated with the permeability of the water-saturated sample S4 provided in an embodiment of the present application;

[0076] Figure 18 A graph showing the Reynolds number friction coefficient associated with the permeability of the water-saturated sample S5 provided in an embodiment of the present application;

[0077] Figure 19 A graph showing the Reynolds number friction coefficient associated with the permeability of the water-saturated sample S6 provided in an embodiment of the present application;

[0078] Figure 20 A graph showing the Reynolds number friction coefficient associated with the permeability of the water-saturated sample S7 provided in an embodiment of the present application;

[0079] Figure 21 A graph showing the Reynolds number friction coefficient associated with the permeability of the water-saturated sample S8 provided in an embodiment of the present application;

[0080] Figure 22 A graph showing the Reynolds number friction coefficient associated with the permeability of the water-saturated sample S9 provided in an embodiment of the present application;

[0081] Figure 23 A graph showing the Reynolds number friction coefficient associated with the permeability of the water-saturated sample S10 provided in an embodiment of the present application;

[0082] Figure 24 A Reynolds number friction coefficient curve diagram of the water-saturated sample S1 provided in an embodiment of the present application in a double logarithmic coordinate system;

[0083] Figure 25 A Reynolds number friction coefficient curve in a double logarithmic coordinate system of the water-saturated sample S2 provided in an embodiment of the present application;

[0084] Figure 26 A Reynolds number friction coefficient curve in a double logarithmic coordinate system of the water-saturated sample S3 provided in an embodiment of the present application;

[0085] Figure 27 A Reynolds number friction coefficient curve diagram of the water-saturated sample S4 provided in an embodiment of the present application in a double logarithmic coordinate system;

[0086] Figure 28 A Reynolds number friction coefficient curve in a double logarithmic coordinate system of the water-saturated sample S5 provided in an embodiment of the present application;

[0087] Figure 29 A Reynolds number friction coefficient curve in a double logarithmic coordinate system of the water-saturated sample S6 provided in an embodiment of the present application;

[0088] Figure 30 A Reynolds number friction coefficient curve in a double logarithmic coordinate system for the water-saturated sample S7 provided in an embodiment of the present application;

[0089] Figure 31 A Reynolds number friction coefficient curve in a double logarithmic coordinate system for the water-saturated sample S8 provided in an embodiment of the present application;

[0090] Figure 32 A Reynolds number friction coefficient curve diagram of the water-saturated sample S9 provided in an embodiment of the present application in a double logarithmic coordinate system;

[0091] Figure 33 A Reynolds number friction coefficient curve diagram of the water-saturated sample S10 provided in an embodiment of the present application in a double logarithmic coordinate system;

[0092] Figure 34 This is a graph showing the apparent permeability pressure gradient of the water-saturated sample S1 provided in an embodiment of the present application;

[0093] Figure 35 This is a graph showing the apparent permeability pressure gradient of the water-saturated sample S2 provided in an embodiment of the present application;

[0094] Figure 36 This is a graph showing the apparent permeability pressure gradient of the water-saturated sample S3 provided in an embodiment of the present application;

[0095] Figure 37 This is a graph showing the apparent permeability pressure gradient of the water-saturated sample S4 provided in an embodiment of the present application;

[0096] Figure 38 This is a graph showing the apparent permeability pressure gradient of the water-saturated sample S5 provided in an embodiment of the present application;

[0097] Figure 39 This is a graph showing the apparent permeability pressure gradient of the water-saturated sample S6 provided in an embodiment of the present application;

[0098] Figure 40 This is a graph showing the apparent permeability pressure gradient of the water-saturated sample S7 provided in an embodiment of the present application;

[0099] Figure 41 This is a graph showing the apparent permeability pressure gradient of the water-saturated sample S8 provided in an embodiment of the present application;

[0100] Figure 42 This is a graph showing the apparent permeability pressure gradient of the water-saturated sample S9 provided in an embodiment of the present application;

[0101] Figure 43 This is a graph showing the apparent permeability pressure gradient of the water-saturated sample S10 provided in an embodiment of the present application;

[0102] Figure 44 This is a pressure gradient curve of the apparent permeability change rate of the water-saturated sample S1 provided in an embodiment of the present application;

[0103] Figure 45 This is a pressure gradient curve of the apparent permeability change rate of the water-saturated sample S2 provided in an embodiment of the present application;

[0104] Figure 46 This is a pressure gradient curve of the apparent permeability change rate of the water-saturated sample S3 provided in an embodiment of the present application;

[0105] Figure 47 A pressure gradient curve of the apparent permeability change rate of the water-saturated sample S4 provided in an embodiment of the present application;

[0106] Figure 48 This is a pressure gradient curve of the apparent permeability change rate of the water-saturated sample S5 provided in an embodiment of the present application;

[0107] Figure 49 This is a pressure gradient curve of the apparent permeability change rate of the water-saturated sample S6 provided in an embodiment of the present application;

[0108] Figure 50 This is a pressure gradient curve of the apparent permeability change rate of the water-saturated sample S7 provided in an embodiment of the present application;

[0109] Figure 51 This is a pressure gradient curve of the apparent permeability change rate of the water-saturated sample S8 provided in an embodiment of the present application;

[0110] Figure 52 This is a pressure gradient curve of the apparent permeability change rate of the water-saturated sample S9 provided in an embodiment of the present application;

[0111] Figure 53 This is a pressure gradient curve of the apparent permeability change rate of the water-saturated sample S10 provided in an embodiment of the present application;

[0112] Figure 54A correlation diagram of the second minimum stable migration pressure gradient and the first minimum stable migration pressure gradient for all water-saturated samples provided in the embodiments of the present application;

[0113] Figure 55 Schematic diagram of the process of determining the oil migration state of tight sandstone oil reservoirs provided in the embodiment of the present application Figure 2 ;

[0114] Figure 56 A schematic diagram of the structure of an apparatus for determining the migration status of oil in tight sandstone oil reservoirs provided in an embodiment of the present application;

[0115] Figure 57 A schematic diagram of the hardware structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0116] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

[0117] In the embodiments of the present application, words such as "first" and "second" are used to distinguish between identical or similar items with substantially the same functions and effects. Those skilled in the art will understand that words such as "first" and "second" do not limit the quantity and execution order, and words such as "first" and "second" do not necessarily limit differences. It should be noted that in the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described in this application as "exemplary" or "for example" should not be interpreted as being more preferred or advantageous than other embodiments or design schemes. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a concrete way. In the embodiments of the present application, "at least one" refers to one or more, and "more" refers to two or more.

[0118] It should be noted that the phrase "at..." in the embodiments of this application can refer to the instantaneous occurrence of a certain event or a period of time after the occurrence of the certain event, and this is not specifically limited in this embodiment of this application. Furthermore, the method and apparatus for determining the migration status of oil in a tight sandstone oil reservoir provided in the embodiments of this application are merely exemplary. A method and apparatus for determining the migration status of oil in a tight sandstone oil reservoir may also include more or less content.

[0119] To facilitate a clear description of the technical solutions of the embodiments of the present application, some of the terms and technologies involved in the embodiments of the present application are briefly introduced below:

[0120] The Reynolds number and friction coefficient calculation formulas associated with permeability are mathematical expressions used to describe the flow characteristics of fluids in porous media. The Reynolds number is typically used to measure the ratio of inertial force to viscous force in a flow, helping to determine flow conditions, while the friction coefficient describes the frictional resistance between the fluid and the medium. Combined with permeability information, these formulas can help predict flow behavior and pressure loss in porous media.

[0121] The permeability-dependent Reynolds number-friction coefficient curve is a graphical representation that shows the relationship between the Reynolds number and the friction coefficient for fluid flow in porous media, as well as how this relationship is affected by the permeability of the medium. This curve helps understand and predict the dynamic characteristics of fluid flow under different permeability conditions, including transitions in flow regimes and changes in resistance, thus providing a basis for analyzing fluid migration behavior.

[0122] The Permeability Minimum Migration Pressure Gradient Curve is a graphical tool used to represent the relationship between the minimum pressure gradient required to initiate nonlinear migration of fluids in porous media and the permeability of the media. This curve helps determine the minimum gradient required for fluids to overcome quiescent or linear flow and enter nonlinear migration under varying permeability conditions, providing a valuable reference for optimizing fluid production and enhancing oil recovery.

[0123] The permeability minimum stable migration pressure gradient curve is a graphical representation of the relationship between the minimum pressure gradient required for a fluid to transition from nonlinear to linear migration in a porous medium and the permeability of the medium. This curve helps identify the minimum pressure required for stable linear migration under different permeability conditions, providing key data support for flow stability analysis and optimization during fluid production.

[0124] Exemplary embodiments will be described in detail herein, examples of which are illustrated in the accompanying drawings. In the following description, when referring to the drawings, like numbers in different figures represent like or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all possible embodiments consistent with the present invention. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present invention, as detailed in the appended claims.

[0125] The technical solution of the present invention is described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present invention will be described below with reference to the accompanying drawings.

[0126] To clearly understand the technical solution of this application, we first provide a detailed introduction to the existing technology. The migration of oil in tight sandstone reservoirs is primarily studied through laboratory simulations. High-precision experimental equipment is typically used to measure the oil's starting pressure gradient and seepage characteristics under different pressure and temperature conditions. During the experiment, by controlling and adjusting experimental parameters such as pore pressure, fluid viscosity, and rock permeability, the migration of oil in tight sandstone is simulated to observe and record the conditions that initiate oil migration.

[0127] However, existing technologies have a problem with determining the state of oil migration. When studying oil migration, existing technologies rely solely on laboratory-measured starting pressure gradients to determine the critical conditions for oil migration. However, due to significant differences between laboratory conditions and actual geological environments, coupled with limitations in experimental precision, determining the state of oil migration remains difficult.

[0128] Therefore, in order to address the problem of the inability to determine the oil migration state in existing technologies, research has found that in order to solve this problem, the oil migration state can be determined by establishing a relationship model between oil flow characteristics and sandstone characteristics: ① First, the types of oil migration states can be collected, for example, oil migration states include no migration, nonlinear migration, and linear migration. ② Parameter values ​​for oil migration, nonlinear migration, and linear migration can be collected, and a mathematical model can be constructed based on the parameter values ​​to represent the various oil migration states. ③ Laboratory simulation conditions can be improved to make them closer to the actual geological environment, thereby reducing the deviation between experimental results and actual conditions.

[0129] Specifically:

[0130] First, the flow patterns of oil under different conditions can be identified and classified, such as non-migration, nonlinear migration, and linear migration. Then, relevant physical parameters such as flow velocity, pressure fluctuations, and permeability are collected for these flow patterns. Based on these parameters, a mathematical model is constructed to describe different migration states, and this model is used to simulate and predict oil migration behavior in porous media. To ensure the accuracy and practicality of the model, the model parameters are calibrated through laboratory simulations and field data to better reflect actual geological conditions. Furthermore, the integration of numerical simulation techniques can further verify the reliability of the model and optimize its application in different geological settings. This multi-layered research approach can effectively identify oil migration states.

[0131] The embodiment of the present application provides a method for determining the migration state of oil in tight sandstone oil reservoirs. By obtaining multiple velocity pressure gradient curves and the permeability of tight sandstone samples, the permeability-related Reynolds number friction coefficient curve and the apparent permeability pressure gradient curve are calculated, thereby establishing the permeability minimum migration pressure gradient curve and the minimum stable migration pressure gradient curve. Finally, a migration flow pattern change chart is constructed, which can intuitively display the migration state of oil in different tight sandstone samples, including non-migration areas, nonlinear migration areas, and linear migration areas. This method solves the problem in the prior art that the migration state of oil is difficult to determine due to the difference between laboratory conditions and actual geological environments, and provides a solution for accurately judging the migration state of oil in tight sandstone reservoirs.

[0132] Based on the above creative findings, the technical solution of the present application is proposed.

[0133] The following describes an application scenario of the method for determining the petroleum migration status of tight sandstone oil reservoirs provided by an embodiment of the present invention. Figure 1 Schematic diagram of the application scenario of the method for determining the migration status of tight sandstone oil reservoirs provided in the embodiment of the present application. Figure 1 As shown, the application scenario includes a mobile terminal 101 and a server 102. The mobile terminal 101 obtains multiple flow velocity pressure gradient curves and the permeability of multiple tight sandstone samples, and sends the multiple flow velocity pressure gradient curves and the permeability of multiple tight sandstone samples to the server 102. The server 102 constructs a migration flow pattern change chart based on the multiple flow velocity pressure gradient curves, the Reynolds number and friction coefficient calculation formula associated with the permeability, the apparent permeability calculation formula, and the permeability of multiple tight sandstone samples.

[0134] The embodiments of the present invention are described below with reference to the accompanying drawings.

[0135] Figure 2 Schematic diagram of the process of determining the oil migration state of tight sandstone oil reservoirs provided in the embodiment of the present application Figure 1 .like Figure 2 As shown, in this embodiment, the execution subject of the embodiment of the present invention is a server. The method for determining the oil migration state of tight sandstone oil accumulation provided by this embodiment includes the following steps:

[0136] S201. Obtain the permeability of a plurality of preset tight sandstone samples and a plurality of flow velocity pressure gradient curves.

[0137] Specifically, the permeability and flow velocity-pressure gradient curves of multiple tight sandstone samples can be obtained experimentally. Multiple tight sandstone samples are water-saturated and their pressure gradients are measured at different flow rates, yielding a curve that plots the relationship between flow velocity and pressure gradient. Simultaneously, the permeability of each tight sandstone sample is measured using permeability testing equipment. This data is used to characterize the fluid flow characteristics of the tight sandstone samples and provides a basis for the subsequent calculation of permeability-related Reynolds number friction coefficient curves and apparent permeability pressure gradient curves.

[0138] S202. Calculate the permeability-related Reynolds number friction coefficient curves and apparent permeability pressure gradient curves of the multiple water-saturated samples based on the multiple flow rate pressure gradient curves, the preset permeability-related Reynolds number and friction coefficient calculation formula, and the preset apparent permeability calculation formula.

[0139] Specifically, the Reynolds number and friction coefficient for each sample can be calculated using flow velocity and pressure gradient data. Then, the apparent permeability formula is applied to generate an apparent permeability-pressure gradient curve. These calculation results are used to generate permeability-dependent Reynolds number-friction coefficient curves and apparent permeability-pressure gradient curves, helping to analyze the flow characteristics of water-saturated samples under different flow conditions and laying the foundation for the subsequent development of migration and flow regime change maps.

[0140] Among them, the calculation formulas of friction coefficient, Reynolds number and apparent permeability can be expressed as:

[0141]

[0142] Where F is the friction coefficient, is porosity, ΔP is pressure difference, ρ is fluid density, v is fluid velocity, L is core length, K a is the apparent permeability, Re is the Reynolds number, μ is the fluid viscosity, A is the core cross-sectional area, and Q is the fluid flow rate.

[0143] S203 , establishing a permeability minimum migration pressure gradient curve and a permeability minimum stable migration pressure gradient curve based on multiple permeabilities, multiple permeability-related Reynolds number friction coefficient curves, and multiple apparent permeability pressure gradient curves.

[0144] Specifically, the critical pressure gradient corresponding to each permeability can be determined first, that is, the minimum pressure gradient at which fluid migration begins and the minimum pressure gradient at which stable migration is achieved. These critical pressure gradient values ​​are used to plot the minimum permeability migration pressure gradient curve and the minimum stable permeability migration pressure gradient curve. These curves are used to identify the flow initiation and flow stability conditions under different permeabilities, providing a basis for constructing migration pattern change maps, thereby helping to determine the migration state of oil in different samples.

[0145] S204. Construct a migration flow pattern change chart based on the permeability minimum migration pressure gradient curve and the permeability minimum stable migration pressure gradient curve.

[0146] Specifically, these two curves can be plotted in the same coordinate system, with permeability as the horizontal axis and pressure gradient as the vertical axis, to form a chart. This chart is used to divide different flow regimes and clearly show the pressure gradient ranges where oil cannot migrate, migrates nonlinearly, and migrates linearly in the sample under different permeability conditions. This chart provides an intuitive reference tool for judging the state of oil migration in practical applications, helping to optimize oil production and improve oil recovery. Among them, the migration flow regime change chart is used to display the migration state of oil in multiple tight sandstone samples. The migration flow regime change chart includes no migration zone, nonlinear migration zone, and linear migration zone. No migration zone, nonlinear migration zone, and linear migration zone refer to areas where oil cannot migrate, undergoes nonlinear migration, and undergoes linear migration in multiple tight sandstone samples, respectively.

[0147] For example, Figure 3 This is a diagram of the flow pattern changes provided in the embodiment of this application. Figure 3 As shown, the coordinate system can be divided into three regions based on the distribution of the two curves on the coordinate system: the non-migration zone below the minimum permeability migration pressure gradient curve, the nonlinear oil migration zone between the minimum permeability migration pressure gradient curve and the minimum stable permeability migration pressure gradient curve, and the linear stable oil migration zone above the minimum stable permeability migration pressure gradient curve. By establishing this chart, the actual flow state of oil in tight sandstone can be determined based on the actual permeability and oil pressure gradient.

[0148] Nonlinear migration is characterized by upward concave non-Darcy slow migration, while linear migration is characterized by linear quasi-Darcy rapid migration. Under the upward concave non-Darcy slow migration regime, oil flow does not follow the classic Darcy law and exhibits significant nonlinear characteristics. The relationship between flow velocity and pressure gradient exhibits an upward concave shape, indicating that under low pressure gradients, flow resistance is greater, resulting in slower migration. This phenomenon is often associated with the complex pore structure of tight sandstone and the viscous effects of the fluid, and typically occurs in media with low permeability or complex pore structures.

[0149] Linear quasi-Darcy rapid migration is another type of fluid flow regime in which the oil flow characteristics approach the linear characteristics of Darcy's law, and the relationship between flow velocity and pressure gradient can be approximately described by a linear model. In this regime, the rapid migration velocity indicates that under high pressure gradients, flow resistance is relatively low, allowing oil to pass more smoothly through rock pores. This migration regime typically occurs under conditions of high permeability or large pressure gradients.

[0150] This embodiment provides a method for determining the migration state of oil in a tight sandstone oil reservoir, the method comprising: obtaining a plurality of preset flow velocity pressure gradient curves and the permeability of a plurality of tight sandstone samples; calculating the permeability-related Reynolds number friction coefficient curves and the apparent permeability pressure gradient curves of a plurality of water-saturated samples based on the plurality of flow velocity pressure gradient curves, a preset permeability-related Reynolds number and friction coefficient calculation formula, and a preset apparent permeability calculation formula; establishing a minimum permeability migration pressure gradient curve and a minimum stable permeability migration pressure gradient curve based on the plurality of permeabilities, the plurality of permeability-related Reynolds number friction coefficient curves, and the plurality of apparent permeability pressure gradient curves; and constructing a migration flow state change map based on the minimum permeability migration pressure gradient curve and the minimum stable permeability migration pressure gradient curve. A method for determining the migration state of oil in tight sandstone reservoirs achieves the following technical effects: by obtaining multiple velocity pressure gradient curves and the permeability of tight sandstone samples, the permeability-related Reynolds number friction coefficient curve and apparent permeability pressure gradient curve are calculated, thereby establishing the minimum permeability migration pressure gradient curve and the minimum stable migration pressure gradient curve. Finally, a migration flow pattern variation chart is constructed, which can intuitively display the migration state of oil in different tight sandstone samples, including non-migration zones, nonlinear migration zones, and linear migration zones. This method solves the problem of difficulty in determining oil migration state in existing technologies due to the difference between laboratory conditions and actual geological environments, and provides a solution for accurately determining the migration state of oil in tight sandstone reservoirs.

[0151] In one possible design, S201 obtains the permeability of a plurality of preset tight sandstone samples and a plurality of flow velocity and pressure gradient curves, including:

[0152] S2011. Obtain multiple tight sandstone samples and the permeability of the multiple tight sandstone samples.

[0153] Specifically, multiple tight sandstone samples and the permeability of multiple tight sandstone samples can be obtained through a combination of field sampling and laboratory testing. First, representative tight sandstone samples are collected from the target geological layer to ensure that the permeability and porosity ranges of these samples meet the research requirements. Then, the permeability of each sample is measured in the laboratory using permeability testing equipment to ensure that it is less than the preset first threshold. These data are used for subsequent water saturation treatment and oil migration simulation experiments to help establish flow rate pressure gradient curves and provide basic data for analyzing oil migration status. Among them, the permeabilities of multiple tight sandstone samples are different, the porosities of multiple tight sandstone samples are different, and multiple porosities and multiple permeabilities are all less than the preset first threshold.

[0154] For example, multiple tight sandstone samples from the Chang 6-Chang 8 tight sandstone reservoir are collected and tested for gas porosity and permeability. Ten samples are selected from the multiple tight sandstone samples and are denoted as H1 to H10. The porosity and permeability of the 10 tight sandstone samples are different. The first threshold can be set to 1.0 mD. The porosity and permeability of the 10 tight sandstone samples are all less than 1.0 mD. The permeabilities of the 10 tight sandstone samples are distributed between 0.01-0.1 mD, 0.1-0.6 mD, and 0.6-1.0 mD. The porosity and permeability of the 10 tight sandstone samples are shown in Table 1.

[0155] Table 1

[0156] Sample number Porosity (%) Permeability (mD) H1 12.03 0.145 H2 10.12 0.315 H3 9.01 0.059 H4 11.62 0.408 H5 5.91 0.087 H6 12.63 0.191 H7 9.03 0.603 H8 9.01 0.115 H9 9.01 0.088 H10 6.71 0.071

[0157] S2012. Perform water saturation treatment on multiple dense sandstone samples to obtain multiple water-saturated samples.

[0158] Specifically, ten tight sandstone samples (H1 to H10) were saturated with water in the laboratory using either vacuum or pressure saturation methods, yielding ten water-saturated samples (S1 to S10). The tight sandstone samples were placed in a saturation device, where air was removed by vacuum pumping. Water was then introduced under a specific pressure, allowing the water to fully penetrate the pores of the samples until saturation was achieved. The resulting ten water-saturated samples (S1 to S10) were used in petroleum migration simulation experiments.

[0159] S2013. Conduct petroleum migration simulation experiments on multiple water-saturated samples to obtain flow rate pressure gradient curves of the multiple water-saturated samples.

[0160] Specifically, a water-saturated sample can be placed in a specially designed core holder, which is then placed in a thermostat controlled at 85°C, close to formation temperature. The confining pressure is the formation pressure of a tight sandstone reservoir. Oil is then injected into the inlet of each tight sandstone sample at a low pressure for a period of time, and the outlet is observed. Once the oil flows steadily out of the outlet, the pressure is maintained for a period of time until no water flows out of the outlet and the oil flow rate stabilizes. The oil injection pressure at the inlet is then increased. This pressure is then gradually increased until no water flows out of the outlet and the oil flow rates at the inlet and outlet are essentially equal. The corresponding flow rate and pressure are recorded at each pressure gradient, ensuring that the system reaches a stable state after each pressure adjustment. The recorded flow rate and pressure gradient data are then collated and analyzed.

[0161] Figures 4 to 13 The flow rate and pressure gradient curves of the water-saturated sample S1 to the water-saturated sample S10 provided in the embodiments of the present application are shown in FIG. Figure 4 Taking the water-saturated sample S1 as an example, Figure 4 The relationship between the flow rate of water-saturated sample S1 under different pressure gradients is shown. As the pressure gradient increases, the flow rate gradually increases. The flow rate pressure gradient curve of water-saturated sample S1 first increases in a curved manner from left to right and then increases linearly, indicating that the migration of oil in water-saturated sample S1 includes two stages: nonlinear migration and quasi-linear migration. Quasi-linear migration is a transitional state between linear migration and nonlinear migration. Similarly, Figures 5 to 13 The velocity-pressure gradient curve in the figure also shows a trend of first increasing in a curved manner and then in a linear manner from left to right, indicating that the migration of oil in the water-saturated sample S2 to the water-saturated sample S10 also includes two stages: nonlinear migration and quasi-linear migration.

[0162] The technical effect of this solution in this embodiment is that by obtaining multiple tight sandstone samples with different permeabilities and porosities and saturating them with water, a series of velocity-pressure gradient curves for the water-saturated samples are generated. These curves provide a rich data foundation, enabling subsequent analysis to accurately reflect the impact of different physical properties on oil migration behavior.

[0163] In one possible design, S203 establishes a permeability minimum migration pressure gradient curve and a permeability minimum stable migration pressure gradient curve based on multiple permeabilities, multiple permeability-related Reynolds number friction coefficient curves, and multiple apparent permeability pressure gradient curves, including:

[0164] S2031. Based on multiple permeability-related Reynolds number friction coefficient curves and multiple apparent permeability pressure gradient curves, calculate the minimum migration pressure gradient and the minimum stable migration pressure gradient of multiple water-saturated samples.

[0165] Specifically, the critical point for each water-saturated sample can be first identified from the permeability-dependent Reynolds number friction coefficient curve, i.e., the minimum migration pressure gradient at which oil begins nonlinear migration. Then, the minimum stable migration pressure gradient at which oil transitions from nonlinear to linear migration can be determined from the apparent permeability pressure gradient curve. These calculation results are used to establish the permeability minimum migration pressure gradient curve and the permeability minimum stable migration pressure gradient curve, providing data support for constructing migration flow pattern change maps, thereby facilitating the analysis and prediction of oil migration under different geological conditions. The multiple minimum migration pressure gradients refer to the gradients required for oil to begin nonlinear migration in multiple water-saturated samples, and the multiple minimum stable migration pressure gradients refer to the gradients required for oil to transition from nonlinear to linear migration in multiple water-saturated samples.

[0166] For example, the minimum migration pressure gradients of the 10 water-saturated samples S1 to S10 are shown in Table 2.

[0167] Table 2

[0168] Sample number Minimum migration pressure gradient (MPa / cm) S1 0.4812 S2 0.101 S3 2.6548 S4 0.0061 S5 2.3031 S6 0.1966 S7 0.0965 S8 0.5086 S9 3.5279 S10 1.4621

[0169] S2032. Establish a permeability minimum migration pressure gradient curve and a permeability minimum stable migration pressure gradient curve based on multiple permeabilities, multiple minimum migration pressure gradients, and multiple minimum stable migration pressure gradients.

[0170] Specifically, the permeability value of each water-saturated sample can be first paired with its corresponding minimum migration pressure gradient and minimum stable migration pressure gradient. Then, in a coordinate system with permeability as the horizontal axis and the minimum migration pressure gradient and minimum stable migration pressure gradient as the vertical axes, a permeability minimum migration pressure gradient curve and a permeability minimum stable migration pressure gradient curve are plotted. The permeability minimum migration pressure gradient curve can be used as a critical condition identification curve for determining whether oil can migrate in tight reservoirs. Similarly, the permeability minimum stable migration pressure gradient curve can be used as a critical condition identification curve for determining whether oil can migrate stably in tight reservoirs.

[0171] The technical effect of this solution in this embodiment is that by calculating the minimum migration pressure gradient and minimum stable migration pressure gradient for multiple water-saturated samples and establishing corresponding permeability minimum migration pressure gradient curves and permeability minimum stable migration pressure gradient curves, it is possible to accurately identify the migration behavior of oil under different permeability conditions. These curves provide key reference indicators, improving the accuracy of determining the transition conditions from nonlinear to linear oil migration.

[0172] In one possible design, S2031 calculates the minimum migration pressure gradient and the minimum stable migration pressure gradient for multiple water-saturated samples based on multiple permeability-dependent Reynolds number friction coefficient curves and multiple apparent permeability pressure gradient curves, including:

[0173] S20311. Perform function fitting based on multiple apparent permeability pressure gradient curves to obtain multiple apparent permeability pressure gradient formulas.

[0174] Specifically, the apparent permeability pressure gradient data for each water-saturated sample can be collected first. Then, an appropriate mathematical model, such as a linear, nonlinear, or polynomial model, is selected for curve fitting to obtain a fitting formula describing this data. These fitting formulas are used to calculate the minimum migration pressure gradient and the minimum stable migration pressure gradient, helping to establish an accurate permeability pressure gradient curve and providing a reliable mathematical basis for analyzing oil migration status.

[0175] S20312. Calculate the minimum migration pressure gradient of multiple water-saturated samples based on multiple apparent permeability pressure gradient formulas.

[0176] Specifically, the fitted apparent permeability pressure gradient formula can be used to input different flow rate values ​​to calculate the corresponding pressure gradient and identify the critical point where oil begins to migrate nonlinearly, namely the minimum migration pressure gradient. These calculation results are used to establish a permeability minimum migration pressure gradient curve, which helps identify the migration state of oil under different permeability conditions.

[0177] S20313. Calculate the minimum stable migration pressure gradient of multiple water-saturated samples based on multiple permeability-related Reynolds number friction coefficient curves, multiple apparent permeability pressure gradient formulas, and multiple apparent permeability pressure gradient curves.

[0178] Specifically, the pressure gradient at different flow rates can be calculated using the apparent permeability pressure gradient formula. Then, combined with the permeability-dependent Reynolds number friction coefficient curve, the critical point at which oil transitions from nonlinear to linear migration—the minimum stable migration pressure gradient—can be determined. These calculation results are used to establish a permeability minimum stable migration pressure gradient curve, helping to construct a migration flow pattern map, thereby accurately predicting oil migration under different geological conditions.

[0179] The technical effect of this solution in this embodiment is that by performing function fitting on multiple apparent permeability pressure gradient curves to generate an apparent permeability pressure gradient formula, and combining it with the permeability-dependent Reynolds number friction coefficient curve, it is possible to accurately calculate the minimum migration pressure gradient and the minimum stable migration pressure gradient of a water-saturated sample. This method reduces experimental error, enhances the accuracy of petroleum migration analysis, and provides a data foundation for simulating petroleum migration under actual geological conditions.

[0180] In one possible design, the target water-saturated sample is any one of a plurality of water-saturated samples. S20313 calculates the minimum stable migration pressure gradient of the plurality of water-saturated samples based on a plurality of permeability-related Reynolds number friction coefficient curves, a plurality of apparent permeability pressure gradient formulas, and a plurality of apparent permeability pressure gradient curves, including:

[0181] S203131. Calculate the first minimum stable migration pressure gradient of the target water-saturated sample based on the permeability-related Reynolds number friction coefficient curve of the target water-saturated sample.

[0182] Specifically, the critical point where the oil flow transitions from nonlinear to linear migration can be identified from the curve. The pressure gradient corresponding to this point is the first minimum stable migration pressure gradient. This calculation can determine the minimum pressure required to maintain stable linear flow in the target water-saturated sample. The first minimum stable migration pressure gradient is the gradient at which oil transitions from nonlinear to linear migration in the target water-saturated sample.

[0183] For example, Figures 14 to 23The permeability-related Reynolds number friction coefficient curves of the water-saturated samples S1 to S10 provided in the embodiments of the present application are respectively, Figures 24 to 33 The Reynolds number friction coefficient curves of the water-saturated samples S1 to S10 provided in the embodiments of the present application are respectively in a double logarithmic coordinate system. Figure 14 and Figure 24 Take the water-saturated sample S1 as an example, Figure 14 The friction coefficient curve of medium Reynolds number shows a power exponential downward trend from left to right. The downward trend of the curve gradually becomes gentle. The curve enters the inflection point of the nearly horizontal section from the curved section, corresponding to Figure 24 Under the double logarithmic curve, the slope of the curve changes significantly, and the slope is closer to the initial point of -1, corresponding to the Reynolds number reaching 6.94×10 -6 , the friction coefficient reaches 1.64×10 8 When , it indicates that the oil flow has reached the quasi-linear stable migration state, and the pressure gradient value corresponding to this point is defined as the first minimum stable migration pressure gradient. Figures 15 to 23 The Reynolds number friction coefficient curve in the figure also shows a power exponential downward trend from left to right, corresponding to Figures 25 to 33 In the double logarithmic coordinate system, the slope of the curve changes significantly at the inflection point, becoming closer to -1. The pressure gradient value corresponding to this point is determined as the first minimum stable migration pressure gradient from the water-saturated sample S2 to the water-saturated sample S10.

[0184] Figure 24 The Reynolds number friction coefficient curve of water-saturated sample S1 in the double logarithmic coordinate system. The left side of the figure is the fitting curve of the Reynolds number friction coefficient relationship in the nonlinear migration stage of oil, and the right side is the fitting curve of the Reynolds number friction coefficient relationship in the linear migration stage of oil. Both curves show a linear downward trend from left to right; according to the change point of the slope of the two curves, it can be determined Figure 14 The inflection point where the oil flow pattern changes can be defined as the first minimum stable migration pressure gradient. Figures 25 to 33 The two curves in the figure also show a linear downward trend from left to right. Figures 25 to 33 The inflection point of the curve in determines the first minimum stable migration pressure gradient from the water-saturated sample S2 to the water-saturated sample S10.

[0185] S203132. Calculate the second minimum stable migration pressure gradient and the third minimum stable migration pressure gradient of the target water-saturated sample based on the apparent permeability pressure gradient curve of the target water-saturated sample.

[0186] Specifically, the second minimum stable migration pressure gradient can be determined by identifying the lowest pressure gradient in the curve at which oil can maintain linear migration. That is, under this pressure gradient, oil flow remains in a stable linear state. The third minimum stable migration pressure gradient is determined by identifying the minimum pressure gradient at which the apparent permeability is lower than a preset second threshold. This gradient reflects the minimum pressure requirement for maintaining migration under low apparent permeability conditions. The second minimum stable migration pressure gradient refers to the minimum pressure gradient at which oil maintains linear migration in the target water-saturated sample, and the third minimum stable migration pressure gradient refers to the minimum pressure gradient at which the apparent permeability is lower than the preset second threshold in the apparent permeability pressure gradient curve of the target water-saturated sample. The second minimum stable migration pressure gradient is calculated based on the apparent permeability pressure gradient curve, and the third minimum stable migration pressure gradient is calculated based on the apparent permeability change rate pressure gradient curve. The apparent permeability change rate pressure gradient curve is calculated based on the apparent permeability pressure gradient curve.

[0187] For example, Figures 34 to 43 The apparent permeability pressure gradient curves of the water-saturated samples S1 to S10 provided in the embodiments of the present application are shown respectively. Figure 34 Taking the water-saturated S1 sample as an example, Figure 34 The apparent permeability pressure gradient curve of the water-saturated sample S1 and the apparent permeability pressure gradient fitting relationship curve of the water-saturated sample S1 are provided. The apparent permeability pressure gradient curve is obtained by drawing multiple apparent permeabilities and multiple pressure gradients of the water-saturated sample S1, and the apparent permeability pressure gradient fitting relationship curve is obtained by fitting multiple apparent permeabilities and multiple pressure gradients of the water-saturated sample S1. The apparent permeability pressure gradient curve and the apparent permeability pressure gradient fitting relationship curve are approximately consistent, indicating that the fitting curve can well predict the relationship between the apparent permeability and the pressure gradient. Similarly, Figures 36 to 39 ,as well as Figures 41 to 43 The apparent permeability pressure gradient curve in the figure also approximately coincides with the apparent permeability pressure gradient fitting curve, indicating that the fitting curves of water-saturated samples S3 to S6, and water-saturated samples S8 to S10 can well predict the relationship between apparent permeability and pressure gradient. Figure 35 and Figure 40 There are some non-overlapping segments in the fitting curves. This is mainly due to the occasional irregularity in the fluid velocity change. However, this situation rarely occurs and can be ignored.

[0188] Figure 34 The formula for the apparent permeability pressure gradient fitting curve in is:

[0189] Ka=-0.0093x 2 +0.0211x-0.008

[0190] Where x is the pressure gradient, Ka is the apparent permeability, and the correlation coefficient is 0.9885. Solving this formula yields the minimum positive real root of 0.4812 MPa / cm, which is the minimum migration pressure gradient for nonlinear petroleum migration in tight sandstone. Based on this, the formula is differentiated to obtain the limiting tangent equation. Solving this limiting tangent equation yields the minimum positive real root of 1.1344 MPa, which is the second minimum stable migration pressure gradient.

[0191] Figures 44 to 53 The pressure gradient curves of the apparent permeability change rate of the water-saturated sample S1 to the water-saturated sample S10 provided in the embodiments of the present application are shown respectively. Figure 44 Take the water-saturated sample S1 as an example, Figure 44 The horizontal and vertical coordinates are pressure gradient and apparent permeability change rate, respectively. The apparent permeability change rate is the apparent permeability under the current pressure gradient minus the apparent permeability under the previous pressure gradient, divided by the apparent permeability under the previous pressure node. Note that the first pressure gradient node does not need to be calculated. This curve is used to determine the critical point where the oil in the water-saturated sample S1 changes from nonlinear migration to quasi-linear stable migration. The curve shows a trend from left to right of first rapidly decreasing and then stabilizing, indicating that the apparent permeability changes in the migration process are getting smaller and smaller, and the oil flow gradually enters the quasi-linear migration stage. The pressure gradient of 1.060MPa / cm corresponding to the point where the apparent permeability change rate is lower than 5% for the first time is defined as the third minimum stable pressure gradient, that is, when the pressure gradient is exceeded, the apparent permeability of the oil migration basically does not change, and it enters the quasi-linear seepage stage, and stable migration occurs. Similarly, according to Figures 45 to 53 The third minimum stable pressure gradient from the water-saturated sample S2 to the water-saturated sample S10 is calculated.

[0192] S203133. Determine the minimum stable migration pressure gradient of the target water-saturated sample based on the first minimum stable migration pressure gradient, the second minimum stable migration pressure gradient, and the third minimum stable migration pressure gradient.

[0193] Specifically, a correlation map can be established based on the first and second minimum stable migration pressure gradients, a fitting formula for the correlation map can be calculated, and the fourth minimum stable migration pressure gradient can be calculated based on the fitting formula. If the difference between the first and second minimum stable migration pressure gradients is less than or equal to a preset threshold, the first minimum stable migration pressure gradient is taken as the minimum stable migration pressure gradient for the target water-saturated sample. If the difference between the first and second minimum stable migration pressure gradients is greater than the preset threshold, the fourth minimum stable migration pressure gradient is taken as the minimum stable migration pressure gradient for the target water-saturated sample. The first, second, third, fourth, and minimum stable migration pressure gradients for 10 water-saturated samples are shown in Table 3.

[0194] Table 3

[0195]

[0196] For example, Figure 54 This is a correlation diagram of the second minimum stable migration pressure gradient and the first minimum stable migration pressure gradient for all water-saturated samples provided in the embodiments of the present application. Figure 54 The horizontal axis is the second minimum stable migration pressure gradient, and the vertical axis is the first minimum stable migration pressure gradient. Figure 54 As can be observed, most data points are concentrated near the diagonal line, indicating a somewhat linear relationship between the first and second minimum stable migration pressure gradients, but not a perfect match. This indicates that the difference between the first and second minimum stable migration pressure gradients is small in these samples. However, some data points deviate significantly from the diagonal line, showing significant differences between the two. This may be related to factors such as the sample's physical properties, pore structure, or experimental conditions.

[0197] like Figure 54 As shown in Table 3, the first minimum stable migration pressure gradient, the second minimum stable migration pressure gradient and the third minimum stable migration pressure gradient are compared. It can be found that the first minimum stable migration pressure gradient and the third minimum stable migration pressure gradient are basically the same or have little difference, and the first minimum stable migration pressure gradient and the second minimum stable migration pressure gradient are quite different. Therefore, the second minimum stable migration pressure gradient and the first minimum stable migration pressure gradient are compared. Figure 54 By comparing them in the coordinate system of , the linear relationship fitting formula between the two is obtained through linear fitting:

[0198] t=0.6936m+0.2385

[0199] Among them, m is the second minimum stable migration pressure gradient, t is the first minimum stable migration pressure gradient, and the correlation coefficient is 0.9391. The fourth minimum stable migration pressure gradient can be calculated according to the fitting formula and the second minimum stable migration pressure gradient. The fourth minimum stable migration pressure gradient calculated for the water-saturated sample S1 is 1.059 MPa / cm; for the water-saturated sample S1, the difference between the first minimum stable migration pressure gradient and the second minimum stable migration pressure gradient is within 20% of the first minimum stable migration pressure gradient, and the calculated result is also very close to the first value. Therefore, the first minimum stable migration pressure gradient is taken as the minimum stable migration pressure gradient. For cases where the difference between the first minimum stable migration pressure gradient and the second minimum stable migration pressure gradient is greater than 20%, the fourth minimum stable migration pressure gradient is taken as the minimum stable migration pressure gradient.

[0200] The technical effect of this solution in this embodiment is to determine the minimum stable migration pressure gradient of a sample by calculating the first, second, and third minimum stable migration pressure gradients, respectively. This method allows for detailed analysis of the conditions under which oil flow transitions from nonlinear to linear flow and identifies the minimum pressure gradient required to maintain linear flow. This improves understanding of the pressure requirements of a specific sample under different flow conditions, thereby increasing the accuracy of determining the migration state of oil in tight sandstone reservoirs.

[0201] Figure 55 Schematic diagram of the process of determining the oil migration state of tight sandstone oil reservoirs provided in the embodiment of the present application Figure 2 In this embodiment, Figure 2 Based on the provided examples, the method for determining the migration state of oil in tight sandstone oil reservoirs is further explained. The method for determining the migration state of oil in tight sandstone oil reservoirs includes:

[0202] S5501. Obtain the permeability of multiple preset tight sandstone samples and multiple flow velocity pressure gradient curves; wherein the multiple flow velocity pressure gradient curves are used to express the relationship between the flow velocity and pressure gradient of multiple water-saturated samples, and the multiple water-saturated samples are obtained by water-saturating multiple tight sandstone samples.

[0203] S5502. Based on multiple flow rate pressure gradient curves, preset permeability-associated Reynolds number and friction coefficient calculation formulas, and preset apparent permeability calculation formulas, calculate the permeability-associated Reynolds number friction coefficient curves and apparent permeability pressure gradient curves of multiple water-saturated samples.

[0204] S5503. Establish a permeability minimum migration pressure gradient curve and a permeability minimum stable migration pressure gradient curve based on multiple permeabilities, multiple permeability-related Reynolds number friction coefficient curves, and multiple apparent permeability pressure gradient curves.

[0205] S5504. Construct a migration flow pattern change chart based on the permeability minimum migration pressure gradient curve and the permeability minimum stable migration pressure gradient curve; wherein, the migration flow pattern change chart is used to display the migration state of oil in multiple tight sandstone samples. The migration flow pattern change chart includes a non-migration zone, a nonlinear migration zone, and a linear migration zone. The non-migration zone, the nonlinear migration zone, and the linear migration zone refer to areas where oil cannot migrate, undergoes nonlinear migration, and undergoes linear migration in multiple tight sandstone samples, respectively.

[0206] S5501-S5504 are similar to S201-S204 and will not be described in detail in this embodiment.

[0207] S5505. Determine the permeability physical property value of oil based on the migration flow change chart.

[0208] Specifically, by locating the corresponding locations of oil pressure gradients and permeability on the map, the critical permeability value at which oil migration begins—the permeability value—can be identified. This value represents the minimum permeability required for effective oil migration under the current pressure conditions. This result is used to develop optimized production strategies, ensuring that production conditions can be effectively managed and adjusted during actual oilfield development to maximize recovery and economic benefits.

[0209] S5506. Develop oil extraction strategies based on permeability physical property values.

[0210] Specifically, permeability provides information on the minimum permeability required for effective oil migration under specific geological conditions. Based on this value, water injection, pressure boosting, and other measures can be adjusted to ensure that the reservoir permeability reaches or exceeds this critical value, thereby enabling effective oil migration and production. Furthermore, permeability can be used to optimize well placement and production sequencing to increase recovery rates and economic efficiency.

[0211] The technical effect of this solution in this embodiment is to determine the permeability of oil using the migration flow pattern chart. This process helps identify the minimum permeability required for oil migration in a specific sample, providing key physical property parameters. By determining the critical conditions for oil migration, this method improves the accuracy of determining the migration state of oil in tight sandstone reservoirs, providing an important reference for understanding and predicting oil migration behavior under different geological conditions.

[0212] Figure 56 This is a schematic diagram of the structure of the device for determining the migration state of tight sandstone oil reservoirs provided in the embodiment of the present application. Figure 56 As shown, the device for determining the migration state of oil in tight sandstone oil reservoirs includes:

[0213] The preset data acquisition module 5601 is used to obtain the permeability of multiple preset tight sandstone samples and multiple flow rate pressure gradient curves; wherein the multiple flow rate pressure gradient curves are used to express the relationship between the flow rate and pressure gradient of multiple water-saturated samples, and the multiple water-saturated samples are obtained by water-saturating multiple tight sandstone samples.

[0214] The curve calculation module 5602 is used to calculate the permeability-related Reynolds number friction coefficient curves and apparent permeability pressure gradient curves of multiple water-saturated samples based on multiple flow rate pressure gradient curves, preset permeability-related Reynolds number and friction coefficient calculation formulas, and preset apparent permeability calculation formulas.

[0215] The curve construction module 5603 is used to establish a permeability minimum migration pressure gradient curve and a permeability minimum stable migration pressure gradient curve based on multiple permeabilities, multiple permeability-related Reynolds number friction coefficient curves, and multiple apparent permeability pressure gradient curves.

[0216] The map construction module 5604 is used to construct a migration flow pattern change map based on the permeability minimum migration pressure gradient curve and the permeability minimum stable migration pressure gradient curve; wherein the migration flow pattern change map is used to display the migration status of oil in multiple tight sandstone samples. The migration flow pattern change map includes a non-migration area, a nonlinear migration area, and a linear migration area. The non-migration area, the nonlinear migration area, and the linear migration area refer to areas in which oil cannot migrate, undergoes nonlinear migration, and undergoes linear migration in multiple tight sandstone samples, respectively.

[0217] In one possible design, the preset data acquisition module 5601 includes:

[0218] An acquisition unit is used to acquire multiple dense sandstone samples and the permeability of multiple dense sandstone samples; wherein the permeabilities of the multiple dense sandstone samples are different, the porosities of the multiple dense sandstone samples are different, and the multiple porosities and the multiple permeabilities are all less than a preset first threshold.

[0219] The water saturation unit is used to perform water saturation treatment on multiple dense sandstone samples to obtain multiple water-saturated samples.

[0220] The experimental unit is used to conduct oil migration simulation experiments on multiple water-saturated samples to obtain flow rate pressure gradient curves of the multiple water-saturated samples.

[0221] In one possible design, the curve construction module 5603 includes:

[0222] The gradient calculation unit is used to calculate the minimum migration pressure gradient and the minimum stable migration pressure gradient of multiple water-saturated samples based on multiple permeability-related Reynolds number friction coefficient curves and multiple apparent permeability pressure gradient curves; wherein the multiple minimum migration pressure gradients refer to the gradients required for the oil in the multiple water-saturated samples to begin nonlinear migration, and the multiple minimum stable migration pressure gradients refer to the gradients required for the oil in the multiple water-saturated samples to transition from nonlinear migration to linear migration.

[0223] The curve building unit is used to build a permeability minimum migration pressure gradient curve and a permeability minimum stable migration pressure gradient curve according to multiple permeabilities, multiple minimum migration pressure gradients and multiple minimum stable migration pressure gradients.

[0224] In one possible design, the gradient calculation unit includes:

[0225] The function fitting device is used to perform function fitting based on multiple apparent permeability pressure gradient curves to obtain multiple apparent permeability pressure gradient formulas.

[0226] A calculation device is used to calculate the minimum migration pressure gradient of multiple water-saturated samples based on multiple apparent permeability pressure gradient formulas.

[0227] A gradient calculation device is used to calculate the minimum stable migration pressure gradient of multiple water-saturated samples based on multiple permeability-related Reynolds number friction coefficient curves, multiple apparent permeability pressure gradient formulas and multiple apparent permeability pressure gradient curves.

[0228] In one possible design, the target water-saturated sample is any one of a plurality of water-saturated samples, and the gradient calculation device includes:

[0229] The first gradient calculation component is used to calculate the first minimum stable migration pressure gradient of the target water-saturated sample based on the permeability-related Reynolds number friction coefficient curve of the target water-saturated sample; wherein the first minimum stable migration pressure gradient refers to the gradient at which oil in the target water-saturated sample changes from nonlinear migration to linear migration.

[0230] The second gradient calculation component is used to calculate the second minimum stable migration pressure gradient and the third minimum stable migration pressure gradient of the target water-saturated sample based on the apparent permeability pressure gradient curve of the target water-saturated sample; wherein, the second minimum stable migration pressure gradient refers to the minimum pressure gradient for oil to maintain linear migration in the target water-saturated sample, and the third minimum stable migration pressure gradient refers to the minimum pressure gradient in the apparent permeability pressure gradient curve of the target water-saturated sample, in which the apparent permeability is lower than the preset second threshold value. The second minimum stable migration pressure gradient is calculated based on the apparent permeability pressure gradient curve, the third minimum stable migration pressure gradient is calculated based on the apparent permeability change rate pressure gradient curve, and the apparent permeability change rate pressure gradient curve is calculated based on the apparent permeability pressure gradient curve.

[0231] The gradient determination component is used to determine the minimum stable migration pressure gradient of the target water-saturated sample based on the first minimum stable migration pressure gradient, the second minimum stable migration pressure gradient and the third minimum stable migration pressure gradient.

[0232] In one possible design, the apparatus for determining the migration status of oil in a tight sandstone oil reservoir further includes:

[0233] The physical property value determination module is used to determine the permeability physical property value of oil based on the migration flow change map; wherein the permeability physical property value refers to the lowest permeability value that can enable oil to migrate in multiple tight sandstone samples.

[0234] The strategy formulation module is used to formulate oil extraction strategies based on permeability physical property values.

[0235] The device for determining the migration status of tight sandstone oil reservoirs provided in this embodiment can be executed Figure 2 and Figure 55 The technical solution of the method embodiment shown in the figure has the same implementation principle and technical effect as Figure 2 and Figure 55 The method embodiments shown are similar and will not be described in detail here.

[0236] Figure 57 Schematic diagram of the hardware structure of the electronic device provided in the embodiment of the present application. Figure 57 As shown, the electronic device includes: at least one processor 5710 and a memory 5720. The electronic device also includes a communication component 5730. The processor 5710, the memory 5720 and the communication component 5730 are connected via a bus 5740.

[0237] During the specific implementation process, at least one processor 5710 executes the computer-executable instructions stored in the memory 5720, so that at least one processor 5710 is used to implement the method for determining the oil migration status of tight sandstone oil accumulation in the above embodiment.

[0238] The specific implementation process of processor 5710 can be found in the above-mentioned method embodiment. Its implementation principle and technical effects are similar, and will not be repeated here in this embodiment.

[0239] In the above embodiment, it should be understood that the processor 5710 can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), etc. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in the present invention can be directly implemented by a hardware processor or performed by a combination of hardware and software modules in the processor.

[0240] The memory 5720 may include a high-speed RAM memory, and may also include a non-volatile storage NVM, such as at least one disk storage.

[0241] Bus 5740 can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus. Bus 5740 can be classified as an address bus, a data bus, a control bus, etc. For ease of illustration, the bus 5740 in the drawings of this application is not limited to a single bus or a single type of bus.

[0242] The above-mentioned functions implemented by the electronic device and the main control device have introduced the solutions provided by the embodiments of the present invention. It can be understood that in order to implement the above-mentioned functions, the electronic device or the main control device includes hardware structures and / or software modules corresponding to the execution of each function. In combination with the units and algorithm steps of the various examples described in the embodiments disclosed in the embodiments of the present invention, the embodiments of the present invention can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the technical solution of the embodiments of the present invention.

[0243] The present application also provides a computer-readable storage medium storing computer-executable instructions. When executed by a processor, the computer-executable instructions implement the method for determining the migration status of oil in a tight sandstone oil reservoir described in the aforementioned embodiment. In the specific implementation of the aforementioned method for determining the migration status of oil in a tight sandstone oil reservoir, each module may be implemented as a processor.

[0244] The above-mentioned readable storage medium can be implemented by any type of volatile or non-volatile memory device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk. The readable storage medium can be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0245] An exemplary readable storage medium is coupled to a processor so that the processor can read information from the readable storage medium and write information to the readable storage medium. Of course, the readable storage medium can also be an integral part of the processor. The processor and the readable storage medium can be located in an application specific integrated circuit (ASIC). Of course, the processor and the readable storage medium can also exist as discrete components in an electronic device or a main control device.

[0246] An embodiment of the present application further provides a computer program product, including a computer program. When the computer program is executed by a processor, it is used to implement the method for determining the oil migration state of tight sandstone oil accumulation of the above embodiment.

[0247] The computer program is stored in a readable storage medium. At least one processor can read the computer program from the readable storage medium, and at least one processor can execute the computer program to perform the solution provided in any of the above embodiments.

[0248] Those skilled in the art will appreciate that all or part of the steps in the above-described method embodiments can be implemented using hardware associated with program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0249] So far, the technical solution of the present application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the scope of protection of the present application is obviously not limited to these specific embodiments. The above embodiments are only used to illustrate the technical solution of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solution to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for determining the migration status of oil in tight sandstone oil reservoirs, characterized in that: include: Obtaining the permeability of a plurality of preset tight sandstone samples and a plurality of flow velocity and pressure gradient curves; wherein the plurality of flow velocity and pressure gradient curves are used to express the relationship between the flow velocity and the pressure gradient of a plurality of water-saturated samples, wherein the plurality of water-saturated samples are obtained by water-saturating the plurality of tight sandstone samples; Calculating the permeability-related Reynolds number friction coefficient curves and the apparent permeability pressure gradient curves of the plurality of water-saturated samples according to the plurality of flow rate pressure gradient curves, the preset permeability-related Reynolds number and friction coefficient calculation formula, and the preset apparent permeability calculation formula; Establishing a permeability minimum migration pressure gradient curve and a permeability minimum stable migration pressure gradient curve based on the multiple permeabilities, the multiple permeability-related Reynolds number friction coefficient curves, and the multiple apparent permeability pressure gradient curves; A migration flow pattern change chart is constructed based on the permeability minimum migration pressure gradient curve and the permeability minimum stable migration pressure gradient curve; wherein, the migration flow pattern change chart is used to display the migration state of oil in the multiple tight sandstone samples, and the migration flow pattern change chart includes a non-migration zone, a nonlinear migration zone and a linear migration zone, and the non-migration zone, the nonlinear migration zone and the linear migration zone refer to the areas where the oil cannot migrate, undergoes nonlinear migration and undergoes linear migration in the multiple tight sandstone samples, respectively.

2. The method for determining the petroleum migration state of tight sandstone oil accumulation according to claim 1, characterized in that: The step of obtaining the permeability of a plurality of preset tight sandstone samples and a plurality of flow velocity pressure gradient curves includes: Obtaining the plurality of tight sandstone samples and the permeabilities of the plurality of tight sandstone samples; wherein the plurality of tight sandstone samples have different permeabilities, the plurality of tight sandstone samples have different porosities, and the plurality of porosities and the plurality of permeabilities are both less than a preset first threshold; performing water saturation treatment on the plurality of tight sandstone samples to obtain the plurality of water-saturated samples; An oil migration simulation experiment is performed on the multiple water-saturated samples to obtain flow rate pressure gradient curves of the multiple water-saturated samples.

3. The method for determining the petroleum migration status of tight sandstone oil accumulation according to claim 1, characterized in that: The step of establishing a permeability minimum migration pressure gradient curve and a permeability minimum stable migration pressure gradient curve based on the multiple permeabilities, the multiple permeability-related Reynolds number friction coefficient curves, and the multiple apparent permeability pressure gradient curves includes: The minimum migration pressure gradient and the minimum stable migration pressure gradient of the plurality of water-saturated samples are calculated based on the plurality of permeability-dependent Reynolds number friction coefficient curves and the plurality of apparent permeability pressure gradient curves; wherein the plurality of minimum migration pressure gradients refer to the gradients required for the oil in the plurality of water-saturated samples to initiate nonlinear migration, and the plurality of minimum stable migration pressure gradients refer to the gradients required for the oil in the plurality of water-saturated samples to transition from nonlinear migration to linear migration; The permeability minimum migration pressure gradient curve and the permeability minimum stable migration pressure gradient curve are established according to the multiple permeabilities, the multiple minimum migration pressure gradients, and the multiple minimum stable migration pressure gradients.

4. The method for determining the petroleum migration state of tight sandstone oil accumulation according to claim 3, characterized in that: The step of calculating the minimum migration pressure gradient and the minimum stable migration pressure gradient of the plurality of water-saturated samples based on the plurality of permeability-related Reynolds number friction coefficient curves and the plurality of apparent permeability pressure gradient curves comprises: Performing function fitting based on the multiple apparent permeability pressure gradient curves to obtain multiple apparent permeability pressure gradient formulas; Calculating the minimum migration pressure gradient of the plurality of water-saturated samples according to the plurality of apparent permeability pressure gradient formulas; The minimum stable migration pressure gradient of the plurality of water-saturated samples is calculated according to the plurality of permeability-related Reynolds number friction coefficient curves, the plurality of apparent permeability pressure gradient formulas, and the plurality of apparent permeability pressure gradient curves.

5. The method for determining the petroleum migration status of tight sandstone oil accumulation according to claim 4, characterized in that: The target water-saturated sample is any one of the multiple water-saturated samples, and the calculating, based on the multiple permeability-related Reynolds number friction coefficient curves, the multiple apparent permeability pressure gradient formulas, and the multiple apparent permeability pressure gradient curves, of the minimum stable migration pressure gradient of the multiple water-saturated samples includes: Calculating a first minimum stable migration pressure gradient of the target water-saturated sample based on a permeability-dependent Reynolds number friction coefficient curve of the target water-saturated sample; wherein the first minimum stable migration pressure gradient refers to a gradient at which oil in the target water-saturated sample transitions from nonlinear migration to linear migration; According to the apparent permeability pressure gradient curve of the target water-saturated sample, a second minimum stable migration pressure gradient and a third minimum stable migration pressure gradient of the target water-saturated sample are calculated; wherein, the second minimum stable migration pressure gradient refers to the lowest pressure gradient for maintaining linear migration of oil in the target water-saturated sample, and the third minimum stable migration pressure gradient refers to the minimum pressure gradient in the apparent permeability pressure gradient curve of the target water-saturated sample at which the apparent permeability is lower than a preset second threshold value. The second minimum stable migration pressure gradient is calculated based on the apparent permeability pressure gradient curve, and the third minimum stable migration pressure gradient is calculated based on the apparent permeability change rate pressure gradient curve. The apparent permeability change rate pressure gradient curve is calculated based on the apparent permeability pressure gradient curve; The minimum stable migration pressure gradient of the target water-saturated sample is determined according to the first minimum stable migration pressure gradient, the second minimum stable migration pressure gradient, and the third minimum stable migration pressure gradient.

6. The method for determining the petroleum migration status of tight sandstone oil accumulation according to claim 1, characterized in that: After constructing the migration flow pattern change chart based on the permeability minimum migration pressure gradient curve and the permeability minimum stable migration pressure gradient curve, the method further includes: Determining the permeability physical property value of the oil based on the migration flow pattern change chart; wherein the permeability physical property value refers to the lowest permeability value that enables the oil to migrate in the plurality of tight sandstone samples; The oil extraction strategy is formulated according to the permeability physical property value.

7. A device for determining the migration status of oil in tight sandstone oil reservoirs, characterized in that: include: A preset data acquisition module is used to obtain the permeability of a plurality of preset tight sandstone samples and a plurality of flow velocity and pressure gradient curves; wherein the plurality of flow velocity and pressure gradient curves are used to express the relationship between the flow velocity and the pressure gradient of a plurality of water-saturated samples, and the plurality of water-saturated samples are obtained by water-saturating the plurality of tight sandstone samples; a curve calculation module, configured to calculate the permeability-related Reynolds number friction coefficient curves and the apparent permeability pressure gradient curves of the plurality of water-saturated samples based on the plurality of flow rate pressure gradient curves, a preset permeability-related Reynolds number and friction coefficient calculation formula, and a preset apparent permeability calculation formula; a curve building module for building a permeability minimum migration pressure gradient curve and a permeability minimum stable migration pressure gradient curve based on the multiple permeabilities, the multiple permeability-related Reynolds number friction coefficient curves, and the multiple apparent permeability pressure gradient curves; A map construction module is used to construct a migration flow pattern change map based on the permeability minimum migration pressure gradient curve and the permeability minimum stable migration pressure gradient curve; wherein, the migration flow pattern change map is used to display the migration state of oil in the multiple tight sandstone samples, and the migration flow pattern change map includes a non-migration area, a nonlinear migration area and a linear migration area, and the non-migration area, the nonlinear migration area and the linear migration area refer to the areas where the oil cannot migrate, undergoes nonlinear migration and undergoes linear migration in the multiple tight sandstone samples, respectively.

8. An electronic device, characterized in that: include: a processor, and a memory communicatively connected to the processor; The memory stores computer-executable instructions; When the processor executes the computer-executable instructions stored in the memory, it is used to implement the method for determining the oil migration status of tight sandstone oil accumulation according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the method for determining the petroleum migration status of tight sandstone oil accumulation according to any one of claims 1 to 6.

10. A computer program product, comprising a computer program, wherein when the computer program is executed by a processor, the computer program is used to implement the method for determining the petroleum migration state of tight sandstone oil accumulation according to any one of claims 1 to 6.

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