Method, system and device for predicting residual gas of dense fluvial facies reservoir and medium

Abstract

The invention discloses a dense fluvial facies reservoir residual gas prediction method, system and device and a medium, and the method comprises the steps: determining the composition of a gas storage unit and a flow choking unit, and further obtaining the type and distribution of the flow choking unit; and whether residual gas exists in the dense fluvial facies reservoir is judged according to the median of the vertical extension height and the transverse extension length of the crack, the perforation position of the gas well and the type and distribution of the flow blocking unit, and the distribution of the residual gas in the dense fluvial facies reservoir is obtained. According to the method, the actual condition in the development process of the dense fluvial facies reservoir is fully considered, the distribution of the choke units in the reservoir is considered, the extension condition of the hydraulic fracturing crack is also considered, geological factors and engineering factors are comprehensively considered, the method is closer to the actual production condition, the prediction precision is improved, and the residual gas prediction reliability is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of gas field development and reservoir description, and relates to a method, system, device and medium for predicting remaining gas in a tight river phase reservoir. Background Art

[0002] Tight river phase reservoirs are dense, with poor physical properties and limited gas well seepage range. At the same time, the internal structure of the reservoir is complex, and different levels of flow-blocking units have different degrees of obstruction to natural gas seepage. For many reasons, the distribution of residual gas in tight river phase reservoirs is complex and the development potential is difficult to accurately evaluate, which restricts the potential of residual gas in the middle and late stages of development and is not conducive to improving the recovery rate of gas reservoirs. The existing residual gas characterization methods mainly use fine structural research methods, sedimentary microfacies research methods, dynamic monitoring methods, stochastic modeling and numerical simulation methods, but each method has certain limitations, specifically:

[0003] Fine structural research method: Through fine structural analysis of gas-bearing strata, the influence of structure on the distribution of remaining gas is clarified, so as to predict the remaining gas. This method is usually applicable to gas reservoirs of structural origin, but not to tight lithological gas reservoirs.

[0004] Sedimentary microfacies research method: Through sedimentary microfacies research, analyze and identify sedimentary microfacies with good physical properties. If the microfacies (sand body) has not been mined, the distribution of remaining gas can be determined. This method is usually applicable to high permeability gas reservoirs. For tight gas reservoirs, there is no one-to-one correspondence between sedimentary microfacies types and gas-bearing characteristics.

[0005] Dynamic monitoring method: The existence of residual gas is determined by monitoring the production dynamics of gas wells or formation pressure. That is, if the production dynamics of gas wells are good or the formation pressure is high, there will be more residual gas around the well. The residual gas determined by this method is actually the reservoir that the well has already controlled. Generally, it can be produced without taking new measures. Therefore, this method only predicts the residual gas that has not been produced yet.

[0006] Stochastic modeling and numerical simulation methods: The distribution of residual gas is predicted by multiple modeling and numerical simulation methods. This method can intuitively predict the spatial distribution location and scale of the residual gas, but the prediction results are affected by the accuracy and precision of the model. The geological model has strong multi-solutions, so the prediction results are also multi-solutions. At the same time, the above methods often ignore the impact of hydraulic fracturing and the distribution of flow-blocking units inside the reservoir on the distribution of residual gas. Summary of the invention

[0007] The purpose of the present invention is to solve the problem of neglecting the effect of hydraulic fracturing and the distribution of flow-blocking units inside the reservoir on the distribution of residual gas in the prior art, and to provide a method, system, device and medium for predicting the residual gas in a tight river phase reservoir.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] A method for predicting remaining gas in tight fluvial facies reservoirs, comprising:

[0010] Obtaining vertical extension height data and lateral extension length data of hydraulic fractures in several tight fluvial facies reservoirs;

[0011] Based on the vertical extension height data and lateral extension length data of hydraulic fracturing cracks in tight fluvial facies reservoirs, the median values ​​of the vertical extension height and lateral extension length of the cracks are obtained;

[0012] Carry out reservoir configuration characterization based on well data, seismic data and dynamic data;

[0013] Based on the interpretation of single well architectural units and the principles of vertical staging and lateral delimitation, the distribution of architectural units in each layer of a single well is determined;

[0014] Based on the interpretation of the configuration unit and the well logging interpretation results, the composition of the gas storage unit and the flow-blocking unit is determined;

[0015] Based on the obtained configurations of the flow blocking unit and the gas storage unit, obtain the type and distribution of the flow blocking unit;

[0016] Based on the median of the vertical extension height and lateral extension length of the fracture, the perforation position of the gas well, and the type and distribution of the flow-blocking unit, it is determined whether there is residual gas in the tight fluvial facies reservoir and the distribution of the residual gas in the tight fluvial facies reservoir is obtained.

[0017] A further improvement of the present invention is:

[0018] Furthermore, the vertical extension height data and lateral extension length data of hydraulic fracturing cracks in tight river facies reservoirs are as follows:

[0019] The vertical extension height data of hydraulic fractures in tight fluvial facies reservoirs include vertical height data of hydraulic fractures in tight fluvial facies reservoirs in sandstone and vertical height data of hydraulic fractures in tight fluvial facies reservoirs in mudstone;

[0020] The lateral extension length data of the hydraulic fracture cracks in the tight fluvial facies reservoir includes the lateral extension length data of the hydraulic fracture cracks in the tight fluvial facies reservoir in sandstone and the lateral extension length data of the hydraulic fracture cracks in the tight fluvial facies reservoir in mudstone.

[0021] Furthermore, based on the vertical extension height data and lateral extension length data of hydraulic fracturing cracks in tight fluvial facies reservoirs, the median values ​​of the vertical extension height and lateral extension length of the cracks are obtained, specifically:

[0022] The vertical height of the fracture in the sandstone is the median of the vertical height data of the hydraulic fracture in the sandstone of the tight fluvial reservoir, denoted as Hs.

[0023] The vertical height of the crack in the mudstone is the median of the vertical height data of the hydraulic fractures in the mudstone of the tight fluvial facies reservoir, denoted as Hn;

[0024] The lateral extension length of the crack in the sandstone is the median of the lateral extension length data of the hydraulic fracture cracks in the sandstone of the tight fluvial reservoir, denoted as Ls.

[0025] The lateral extension length of the crack in the mudstone is the median of the lateral extension length data of the hydraulic fracture cracks in the mudstone of the tight fluvial facies reservoir, and is recorded as Ln.

[0026] Furthermore, dynamic data include well production, pressure, detection data, analytical test data, establishment of oil and water output, water injection daily data, and dynamic analysis.

[0027] Furthermore, the composition of the gas storage unit and the flow-blocking unit is specifically as follows: the shoal and point-bar are the gas storage units in the tight fluvial facies reservoir, and the braided waterway, active waterway, siltation layer inside the shoal and lateral accumulation layer inside the point-bar are the flow-blocking units; the gas storage unit is a configuration unit for storing natural gas in the tight fluvial facies reservoir; the flow-blocking unit is a configuration unit that hinders the seepage of natural gas.

[0028] Furthermore, the types and distribution of obstruction units are as follows: braided waterways and movable waterways completely divide the gas storage units laterally, belonging to Type I obstruction units, and siltation layers and lateral accumulation layers are distributed inside the gas storage units, belonging to Type II obstruction units.

[0029] Furthermore, based on the median of the vertical extension height and lateral extension length of the fracture, the perforation position of the gas well, and the type and distribution of the flow-blocking unit, it is determined whether there is residual gas in the tight river facies reservoir, and the distribution of the residual gas in the tight river facies reservoir is obtained, specifically:

[0030] The farthest distance L1 from the gas well perforation position to the lateral boundary of the single sand body and the farthest distance H1 from the gas well perforation position to the top and bottom boundaries of the single sand body are obtained. If Ln≥L1, Hn≥H1, there is no residual gas in the single sand body; if Ln≤L1, Hn≥H1, there is residual gas in the single sand body, and the distribution position is limited to the horizontal direction; if Ln≥L1, Hn≤H1, there is residual gas in the single sand body, but the distribution position is limited to the vertical direction; if Ln≤L1, Hn≤H1, there is residual gas in the single sand body, and the distribution position is limited to the vertical direction; if Ln≤L1, Hn≤H1, there is residual gas in the single sand body, which is distributed both horizontally and vertically, and is mainly distributed at the far end of the perforation;

[0031] If the perforation position of a gas well is outside the target single sand body, take the width of the type-I flow-blocking unit as K, the width of the type-II flow-blocking unit as Ln1, the distance from the gas well perforation position to the boundary of the perforated single sand body as Ls1, and the planar extension length of the target single sand body as Y. If Ln1 + Ls1 ≤ L1 + K, the fracture network has not extended to the target single sand body, and there is remaining gas in the target sand body; if L1 + K ≤ Ln1 + Ls1 < L1 + K + Y, the fracture network extends to the target single sand body; if Ln1 + Ls1 ≥ L1 + K + Y, there is no remaining gas inside the target single sand body.

[0032] A prediction system for remaining gas in a tight fluvial reservoir, comprising:

[0033] A first acquisition module, which acquires data on the vertical extension height and the lateral extension length of hydraulic fracturing fractures in a plurality of tight fluvial reservoirs.

[0034] A second acquisition module, which acquires the median values of the vertical extension height and the lateral extension length of the fractures based on the data on the vertical extension height and the lateral extension length of hydraulic fracturing fractures in the tight fluvial reservoir.

[0035] A construction module, which conducts reservoir architecture characterization based on well data, seismic data, and dynamic data.

[0036] A first determination module, which determines the distribution of each layer of architecture units of a single well according to the interpretation of single-well architecture units, vertical staging, and lateral demarcation principles.

[0037] A second determination module, which determines the composition of gas storage units and flow-blocking units based on the interpretation of architecture units and the results of well logging interpretation.

[0038] A third acquisition module, which acquires the types and distributions of flow-blocking units based on the composition of the acquired flow-blocking units and gas storage units.

[0039] A remaining gas acquisition module, which determines whether there is remaining gas in the tight fluvial reservoir and acquires the distribution of remaining gas in the tight fluvial reservoir based on the median values of the vertical extension height and the lateral extension length of the fractures, the gas well perforation position, and the types and distributions of flow-blocking units.

[0040] A terminal device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the steps of the above method are implemented when the processor executes the computer program.

[0041] A computer-readable storage medium storing a computer program, wherein the steps of the above method are implemented when the computer program is executed by a processor.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] The present invention determines the composition of the gas storage unit and the flow blocking unit, and further obtains the type and distribution of the flow blocking unit; then, through the median of the vertical extension height and the horizontal extension length of the crack, the perforation position of the gas well, the type and distribution of the flow blocking unit, it is judged whether there is residual gas in the tight river phase reservoir, and the distribution of the residual gas in the tight river phase reservoir is obtained. The present invention fully considers the actual situation in the development process of the tight river phase reservoir, not only considers the distribution of the flow blocking unit inside the reservoir, but also considers the extension of the hydraulic fracturing cracks, and comprehensively considers the geological factors and engineering factors, which is closer to the actual production situation, improves the prediction accuracy, and improves the reliability of the residual gas prediction. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0045] Figure 1 It is a schematic flow chart of the method for predicting remaining gas in tight fluvial facies reservoirs of the present invention;

[0046] Figure 2 It is a structural schematic diagram of the system for predicting the remaining gas in the tight river facies reservoir of the present invention;

[0047] Figure 3 This is the relationship diagram between the perforation position of the gas well and the boundary of a single sand body;

[0048] Figure 4 This is a schematic diagram of the remaining gas distribution when the gas well perforation position is outside the target single sand body;

[0049] Figure 5 Schematic diagram of deep hole location and residual gas distribution. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0051] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0052] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0053] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0054] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0055] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0056] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0057] See also Figure 1 The present invention discloses a method for predicting remaining gas in a tight fluvial facies reservoir, comprising:

[0058] S101, obtaining vertical extension height data and lateral extension length data of hydraulic fracturing cracks of a plurality of tight fluvial facies reservoirs.

[0059] The vertical extension height data of hydraulic fractures in tight fluvial reservoirs include the vertical height data of hydraulic fractures in tight fluvial reservoirs in sandstone and the vertical height data of hydraulic fractures in tight fluvial reservoirs in mudstone; the lateral extension length data of hydraulic fractures in tight fluvial reservoirs include the lateral extension length data of hydraulic fractures in tight fluvial reservoirs in sandstone and the lateral extension length data of hydraulic fractures in tight fluvial reservoirs in mudstone. There shall be at least 10 data of each type.

[0060] S102, based on the vertical extension height data and the lateral extension length data of the hydraulic fracturing cracks in the tight fluvial facies reservoir, obtain the median value of the vertical extension height and the lateral extension length of the cracks.

[0061] The vertical height of the fracture in the sandstone is the median of the vertical height data of the hydraulic fracture in the sandstone of the tight fluvial reservoir, denoted as Hs.

[0062] The vertical height of the fracture in mudstone is the median of the vertical height data of hydraulic fractures in mudstone of tight fluvial reservoirs, denoted as Hn;

[0063] The lateral extension length of the fracture in the sandstone is the median of the lateral extension length data of the hydraulic fracture in the sandstone of the tight fluvial reservoir, denoted as Ls.

[0064] The lateral extension length of the fracture in mudstone is the median of the lateral extension length data of hydraulic fractures in mudstone of tight fluvial reservoirs, denoted as Ln.

[0065] S103, constructing a reservoir configuration representation based on well data, seismic data and dynamic data.

[0066] Dynamic data include well production, pressure, detection data, analytical test data, establishment of oil and water output, daily data of water injection accounts, and dynamic analysis.

[0067] Reservoir prototype models refer to various models established by methods such as field geological outcrops, modern river deposits, and dense well network dissection of oil and gas fields that are similar to the tight fluvial facies reservoir being studied.

[0068] S104, determining the distribution of each layer of the single well's architectural units based on the interpretation of the single well's architectural units and the principles of vertical staging and lateral delimitation.

[0069] A structural unit refers to a geological body formed in different geological periods and divided by reservoir interfaces of different levels.

[0070] S105, based on the interpretation of the configuration units and the logging interpretation results, determine the composition of the gas storage unit and the flow-blocking unit. The center bar and point bar are the gas storage units in the tight fluvial reservoir, and the braided channel, active channel, siltation layer inside the center bar and lateral accumulation layer inside the point bar are the flow-blocking units; the gas storage unit is the configuration unit for storing natural gas in the tight fluvial reservoir; the flow-blocking unit is the configuration unit that hinders the seepage of natural gas.

[0071] S106, based on the obtained configurations of the flow blocking unit and the gas storage unit, obtain the type and distribution of the flow blocking unit.

[0072] In river deposits, mud units are mainly braided channels and active channels that completely divide the gas storage units laterally. They are 3-6m thick and about 100m wide. Therefore, they belong to Class I flow-blocking units with strong flow-blocking effects, blocking the lateral flow of fluids. Usually, hydraulic fracturing will find it difficult to penetrate Class I flow-blocking units.

[0073] The siltation layer and lateral accumulation layer are distributed inside the gas storage unit, forming thin sheets with a thickness of about 0.2-0.5m. They belong to Class II flow-blocking units with weak flow-blocking effect. Usually, hydraulic fracturing will penetrate Class II flow-blocking units.

[0074] The siltation layer is often nearly horizontal, thus often hindering the vertical seepage of natural gas.

[0075] Lateral accumulation layers often tend to be imbricate and away from the active waterway, thus often blocking the lateral flow of fluid.

[0076] S107, based on the median of the vertical extension height and the lateral extension length of the fracture, the perforation position of the gas well, and the type and distribution of the flow-blocking unit, determine whether there is residual gas in the tight fluvial facies reservoir, and obtain the distribution of the residual gas in the tight fluvial facies reservoir.

[0077] The farthest distance L1 from the gas well perforation position to the lateral boundary of the single sand body and the farthest distance H1 from the gas well perforation position to the top and bottom boundaries of the single sand body are obtained. If Ln≥L1, Hn≥H1, there is no residual gas in the single sand body; if Ln≤L1, Hn≥H1, there is residual gas in the single sand body, and the distribution position is limited to the horizontal direction; if Ln≥L1, Hn≤H1, there is residual gas in the single sand body, but the distribution position is limited to the vertical direction; if Ln≤L1, Hn≤H1, there is residual gas in the single sand body, and the distribution position is limited to the vertical direction; if Ln≤L1, Hn≤H1, there is residual gas in the single sand body, which is distributed both horizontally and vertically, and is mainly distributed at the far end of the perforation;

[0078] If the perforation position of a gas well is outside the target single sand body, take the width of the type-I flow-blocking unit as K, the width of the type-II flow-blocking unit as Ln1, the distance from the gas well perforation position to the boundary of the perforated single sand body as Ls1, and the planar extension length of the target single sand body as Y. If Ln1 + Ls1 ≤ L1 + K, the fracture network does not extend to the target single sand body, and there is remaining gas in the target sand body; if L1 + K ≤ Ln1 + Ls1 < L1 + K + Y, the fracture network extends to the target single sand body; if Ln1 + Ls1 ≥ L1 + K + Y, there is no remaining gas inside the target single sand body.

[0079] See Figure 2 , the present invention discloses a prediction system for remaining gas in a tight fluvial reservoir, including:

[0080] A first acquisition module, which acquires data on the vertical extension height and horizontal extension length of hydraulic fractures in a number of tight fluvial reservoirs;

[0081] A second acquisition module, which acquires the median values of the vertical extension height and horizontal extension length of the fractures based on the data on the vertical extension height and horizontal extension length of hydraulic fractures in the tight fluvial reservoir;

[0082] A construction module, which constructs a reservoir architecture characterization based on well data, seismic data, and dynamic data;

[0083] A first determination module, which determines the distribution of each layer's architecture units of a single well according to the interpretation of single-well architecture units and the principles of vertical staging and lateral demarcation;

[0084] A second determination module, which determines the composition of gas storage units and flow-blocking units based on the results of architecture unit interpretation and logging interpretation;

[0085] A third acquisition module, which acquires the types and distributions of flow-blocking units based on the composition of the acquired flow-blocking units and gas storage units;

[0086] A remaining gas acquisition module, which determines whether there is remaining gas in the tight fluvial reservoir and acquires the distribution of remaining gas in the tight fluvial reservoir based on the median values of the vertical extension height and horizontal extension length of the fractures, the gas well perforation position, and the types and distributions of flow-blocking units.

[0087] Appendix Figure 3 For the perforation position located inside the single sand body, the distance b from the perforation point to the right boundary of the single sand body is greater than the distance a from the perforation point to the left boundary of the single sand body, and the distance d from the perforation point to the bottom boundary of the single sand body is greater than the distance c from the perforation point to the top boundary of the single sand body;

[0088] Appendix Figure 4The fracture network extends to the target single sand body, but is blocked by the type II internal flow resistance unit of the target single sand body, resulting in residual gas inside the target sand body.

[0089] Example:

[0090] like Figure 5 As shown, Well A is perforated in the single sand body on the left, and the deep hole is located 30m away from the boundary of the single sand body. The width of the Type I blocking unit between the left and right single sand bodies is 120m. After perforation and fracturing in Well A, the overall extension range of the fracture is 200m, that is, the fracture extends to B. Two Type II blocking units are developed in the single sand body on the right. The lower blocking unit is penetrated, while the upper blocking unit is not, forming a blockage. Therefore, the remaining gas is distributed at the top.

[0091] A terminal device is provided in one embodiment of the present invention. The terminal device of this embodiment includes: a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps in the above-mentioned method embodiments are implemented. Alternatively, when the processor executes the computer program, the functions of the modules / units in the above-mentioned device embodiments are implemented.

[0092] The computer program may be divided into one or more modules / units, and the one or more modules / units are stored in the memory and executed by the processor to accomplish the present invention.

[0093] The terminal device may be a computing device such as a desktop computer, a notebook, a PDA, a cloud server, etc. The terminal device may include, but is not limited to, a processor and a memory.

[0094] The processor can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0095] The memory may be used to store the computer program and / or module, and the processor implements various functions of the terminal device by running or executing the computer program and / or module stored in the memory and calling the data stored in the memory.

[0096] If the module / unit integrated in the terminal device is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electric carrier signals and telecommunication signals.

[0097] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0098] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for predicting remaining gas in tight fluvial reservoirs. It is characterized in that include: Obtaining vertical extension height data and lateral extension length data of hydraulic fractures in several tight fluvial facies reservoirs; Based on the vertical extension height data and lateral extension length data of hydraulic fracturing cracks in tight fluvial facies reservoirs, the median values ​​of the vertical extension height and lateral extension length of the cracks are obtained; Carry out reservoir configuration characterization based on well data, seismic data and dynamic data; Based on the interpretation of single well architectural units and the principles of vertical staging and lateral delimitation, the distribution of architectural units in each layer of a single well is determined; Based on the interpretation of the configuration unit and the well logging interpretation results, the composition of the gas storage unit and the flow-blocking unit is determined; Based on the obtained configurations of the flow blocking unit and the gas storage unit, obtain the type and distribution of the flow blocking unit; Based on the median of the vertical extension height and lateral extension length of the fracture, the perforation position of the gas well, and the type and distribution of the flow-blocking unit, it is determined whether there is residual gas in the tight fluvial facies reservoir and the distribution of the residual gas in the tight fluvial facies reservoir is obtained.

2. The method for predicting remaining gas in a tight fluvial facies reservoir according to claim 1, It is characterized in that The vertical extension height data and lateral extension length data of the hydraulic fracturing cracks in the tight river facies reservoir are specifically: The vertical extension height data of hydraulic fractures in tight fluvial facies reservoirs include vertical height data of hydraulic fractures in tight fluvial facies reservoirs in sandstone and vertical height data of hydraulic fractures in tight fluvial facies reservoirs in mudstone; The lateral extension length data of the hydraulic fracture cracks in the tight fluvial facies reservoir includes the lateral extension length data of the hydraulic fracture cracks in the tight fluvial facies reservoir in sandstone and the lateral extension length data of the hydraulic fracture cracks in the tight fluvial facies reservoir in mudstone.

3. The method for predicting remaining gas in a tight fluvial facies reservoir according to claim 2, It is characterized in that The method of obtaining the median of the vertical extension height and the lateral extension length of the hydraulic fracturing cracks in the tight fluvial facies reservoir based on the vertical extension height data and the lateral extension length data is as follows: The vertical height of the fracture in the sandstone is the median of the vertical height data of the hydraulic fracture in the sandstone of the tight fluvial reservoir, denoted as Hs. The vertical height of the crack in the mudstone is the median of the vertical height data of the hydraulic fractures in the mudstone of the tight fluvial facies reservoir, denoted as Hn; The lateral extension length of the crack in the sandstone is the median of the lateral extension length data of the hydraulic fracture cracks in the sandstone of the tight fluvial reservoir, denoted as Ls. The lateral extension length of the crack in the mudstone is the median of the lateral extension length data of the hydraulic fracture cracks in the mudstone of the tight fluvial facies reservoir, and is recorded as Ln.

4. The method for predicting remaining gas in a tight fluvial facies reservoir according to claim 3, It is characterized in that The dynamic data include well production, pressure, detection data, analytical test data, establishment of oil and water output, water injection daily data, and dynamic analysis.

5. The method for predicting remaining gas in a tight fluvial facies reservoir according to claim 4, It is characterized in that The compositions of the gas storage unit and the flow resistance unit are specifically as follows: The channel bar and point bar are gas storage units in the tight fluvial facies reservoir, and the braided channel, active channel, silt deposition layer inside the channel bar, and lateral accretion layer inside the point bar are flow resistance units; the gas storage unit is a configuration unit for storing natural gas in the tight fluvial facies reservoir; the flow resistance unit is a configuration unit for hindering the seepage of natural gas.

6. The method for predicting remaining gas in a tight fluvial facies reservoir according to claim 5, characterized in that, the types and distributions of the flow resistance units are specifically as follows: The braided channel and active channel completely divide the gas storage unit laterally and belong to type I flow resistance units. The silt deposition layer and lateral accretion layer are distributed inside the gas storage unit and belong to type II flow resistance units.

7. The method for predicting remaining gas in a tight fluvial facies reservoir according to claim 6, characterized in that, judging whether there is remaining gas in the tight fluvial facies reservoir and obtaining the distribution of the remaining gas in the tight fluvial facies reservoir based on the median values of the vertical extension height and horizontal extension length of the fractures, the perforation position of the gas well, and the types and distributions of the flow resistance units, specifically as follows: Obtain the maximum distance L1 from the perforation position of the gas well to the lateral boundary of the single sand body and the maximum distance H1 from the perforation position of the gas well to the top and bottom boundaries of the single sand body. If Ln≥L1 and Hn≥H1, there is no remaining gas inside the single sand body; if Ln≤L1 and Hn≥H1, there is remaining gas inside the single sand body, and the distribution position is limited laterally; if Ln≥L1 and Hn≤H1, there is remaining gas inside the single sand body, but the distribution position is limited vertically; if Ln≤L1 and Hn≤H1, there is remaining gas inside the single sand body, and it is distributed both laterally and vertically, mainly distributed at the distal position from the perforation. If the perforation position of the gas well is outside the target single sand body, take the width of the type I flow resistance unit as K, take the width of the type II flow resistance unit as Ln1, take the distance from the perforation position of the gas well to the boundary of the perforated single sand body as Ls1, and take the planar extension length of the target single sand body as Y. If Ln1 + Ls1≤L1 + K, the hydraulic fracture network has not extended to the target single sand body, and there is remaining gas in the target sand body; if L1 + K≤Ln1 + Ls1 < L1 + K + Y, the hydraulic fracture network has extended to the target single sand body; if Ln1 + Ls1≥L1 + K + Y, there is no remaining gas inside the target single sand body.

8. A system for predicting remaining gas in a tight fluvial facies reservoir, characterized in that, it includes: A first acquisition module, which acquires data on the vertical extension height and horizontal extension length of hydraulic fractures in a number of tight fluvial facies reservoirs; A second acquisition module, which acquires the median values of the vertical extension height and horizontal extension length of the fractures based on the data on the vertical extension height and horizontal extension length of hydraulic fractures in the tight fluvial facies reservoir; A construction module, which conducts reservoir configuration characterization based on well data, seismic data, and dynamic data; A first determination module, which determines the distribution of each layer of configuration units of a single well according to the interpretation of single-well configuration units, vertical staging, and lateral demarcation principles. A second determination module, wherein the second determination module determines the composition of the gas storage unit and the flow blocking unit based on the configuration unit interpretation and the well logging interpretation results; a third acquisition module, wherein the third acquisition module acquires the type and distribution of the flow blocking unit based on the acquired configuration of the flow blocking unit and the gas storage unit; The residual gas acquisition module determines whether there is residual gas in the tight river phase reservoir based on the median of the vertical extension height and the lateral extension length of the fracture, the perforation position of the gas well, and the type and distribution of the flow-blocking unit, and obtains the distribution of the residual gas in the tight river phase reservoir.

9. A terminal device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, It is characterized in that When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium storing a computer program. It is characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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