Method, system, equipment, medium and program product for depicting residual oil gas in inter-cone zone of bottom water condensate gas reservoir

Abstract

The invention belongs to the technical field of oil reservoir exploitation, and particularly relates to a method, a system, equipment, a medium and a program product for depicting residual oil gas in an inter-cone zone of a bottom water condensate gas reservoir. The description method comprises the following steps: acquiring production dynamic data and reservoir parameters; preliminarily estimating the original reserves and the overall remaining reserves of the oil reservoir; according to the reservoir parameters, a three-dimensional oil reservoir geologic model is constructed through a streamline simulation method, and streamline simulation calculation is carried out after boundary and initial conditions are set; partitioning the overall remaining reserves, comparing the partitioned remaining reserves with a region result of a streamline simulation method, and adjusting parameters when a comparison result is not in a preset range; and depicting the residual oil and gas distribution and evaluating the development potential based on the calibrated streamline simulation method result. The macroscopic result of the material balance method and the microscopic result of the streamline simulation method are compared and calibrated, so that the streamline simulation method can be restrained and verified by using the macroscopic result of the material balance method, and the material balance method can be refined and supplemented by using the microscopic result of the streamline simulation method.

Description

Technical Field

[0001] This invention belongs to the field of oil reservoir development technology, specifically relating to a method, system, equipment, medium, and program product for characterizing residual oil and gas in the intercone zone of bottom water condensate gas reservoirs. Background Technology

[0002] Bottom-water condensate gas reservoirs are a special type of oil and gas reservoir characterized by complex phase changes and seepage characteristics during production. During production, bottom water advances upwards in a cone under the influence of pressure differentials, while condensate gas undergoes a phase change as pressure decreases, separating from the gas phase to form liquid condensate oil. This complex physicochemical process makes the production and assessment of remaining oil and gas in bottom-water condensate gas reservoirs extremely difficult. Accurately characterizing the distribution of remaining oil and gas in the intercone zone is crucial for improving oil and gas recovery rates and optimizing reservoir development strategies.

[0003] The case studies revealed several traditional methods for characterizing the remaining hydrocarbon reserves in the intercone zone of bottom-water condensate gas reservoirs. For example, some existing techniques rely solely on the mass balance method to estimate remaining hydrocarbon reserves, while others employ streamline simulation, which often simplifies the actual characteristics of the reservoir when constructing the model.

[0004] While the mass balance method can estimate the remaining hydrocarbon reserves of a reservoir from a macroscopic perspective, it treats the reservoir as a complete black box model, neglecting the microscopic flow details and heterogeneity within the reservoir. For example, in bottom-water condensate gas reservoirs, the hydrocarbon distribution in the intercone zone is greatly affected by local geological factors such as permeability and porosity. The mass balance method cannot accurately describe the impact of these local variations on the remaining hydrocarbon distribution, resulting in an inaccurate characterization of the remaining hydrocarbon distribution in the intercone zone.

[0005] Simple streamline simulation requires extremely accurate input data, such as reservoir parameters (permeability, porosity, etc.) and boundary conditions. In actual oil reservoirs, these parameters are often difficult to obtain precisely, and simplifying actual reservoir characteristics during model construction can lead to deviations between the model and the actual reservoir. Furthermore, streamline simulation alone lacks macroscopic constraints, making it difficult to effectively verify the reliability of its results. Summary of the Invention

[0006] The purpose of this invention is to provide a method, system, equipment, medium, and program product for characterizing the residual oil and gas distribution in the intercone zone of bottom water condensate gas reservoirs, which solves the problem that existing methods for characterizing the distribution of residual oil and gas in the intercone zone are not accurate enough.

[0007] This invention is achieved through the following technical solution: On one hand, this invention discloses a method for characterizing residual hydrocarbons in the intercone zone of a bottom-water condensate gas reservoir, comprising the following steps: S1. Obtain production dynamics data and reservoir parameters of bottom water condensate gas reservoirs; S2. Based on the acquired production dynamic data, the original reserves and overall remaining reserves of the reservoir are initially estimated using the material balance method. S3. Based on the obtained reservoir parameters, a three-dimensional reservoir geological model is constructed using the streamline simulation method. After setting boundary conditions and initial conditions, streamline simulation calculations are performed to obtain the fluid saturation distribution and streamline orientation at different times. Based on the fluid saturation distribution and streamline at different times, the remaining oil and gas saturation distribution in each region is obtained. S4. After dividing the overall remaining reserves obtained in S2 into zones, compare them with the remaining oil and gas saturation distribution of each region obtained in S3. If the comparison results are not within the preset range, re-evaluate the reservoir parameters of the streamline simulation method or adjust the boundary conditions of the three-dimensional reservoir geological model to obtain the calibrated streamline simulation method results. S5. Characterize the remaining oil and gas distribution based on the calibrated streamline simulation results.

[0008] Furthermore, in S1, the production dynamic data includes the daily gas production, daily water production, cumulative gas production, cumulative water production, and reservoir pressure change data over time for each production well. The specific process for obtaining reservoir parameters involves acquiring spatial distribution data on reservoir permeability, porosity, reservoir thickness, and effective permeability through geological exploration, well logging, and core analysis.

[0009] Furthermore, in S2, the initial reserves and overall remaining reserves of the reservoir are preliminarily estimated using the material balance method, specifically including the following steps: S201. Establish the material balance equation: Based on the phase characteristics of the bottom water condensate gas reservoir and the principle of material conservation, establish a material balance equation that includes the phase change term of condensate gas under different pressures, as well as the balance relationship between the intrusion and production of bottom water. S202. Preliminary Reserve Estimation: Substitute the acquired production dynamic data into the material balance equation to calculate the original geological reserves and overall remaining reserves of the reservoir. The formula for the mass balance equation is as follows: N = \frac{N_p\left[B_g - \left(R_{si} - R_s\right)B_o\right] + W_pB_w - W_eB_w}{B_g - \left(R_{si} - R_s\right)B_o} Where N represents the original geological reserves; N_p represents the cumulative gas production; B_g represents the volume factor of natural gas; R_{si} represents the original dissolved gas-oil ratio; R_s represents the current dissolved gas-oil ratio; B_o represents the volume factor of crude oil; W_p represents the cumulative water production; B_w represents the volume factor of water; and W_e represents the amount of bottom water intrusion.

[0010] Furthermore, S3 specifically includes the following steps: S301. Construct a three-dimensional reservoir geological model based on the reservoir parameters obtained in S1. The three-dimensional reservoir geological model can describe the structural features, lithological distribution, and initial state of fluid distribution of the reservoir. S302. Set the boundary conditions and initial conditions of the three-dimensional reservoir geological model according to the actual production situation of the reservoir; the boundary conditions include the boundary type of the reservoir, and the initial conditions include the initial pressure and the initial saturation. S303. Based on the established three-dimensional reservoir geological model, boundary conditions, and initial conditions, streamline simulation calculations are performed to solve the seepage equation, track the streamline distribution of oil, gas, and water in the reservoir, and obtain the fluid saturation distribution and streamline direction at different times.

[0011] Furthermore, the formula for the streamline simulation method is as follows: \vec{v}=-\frac{k}{\mu}\nabla P Where v represents the seepage velocity vector; k represents the permeability; mu represents the fluid viscosity; and P represents the pressure gradient. In practical simulations, the streamline simulation method uses a three-phase flow equation for multiphase flow. The formula for the three-phase flow equation is as follows: \vec{v}_{o}=-\frac{k_{ro}k}{\mu_{o}}\nabla P_{o} \vec{v}_{g}=-\frac{k_{rg}k}{\mu_{g}}\nabla P_{g} \vec{v}_{w}=-\frac{k_{rw}k}{\mu_{w}}\nabla P_{w} Where vec{v}_{o}, vec{v}_{g}, and vec{v}_{w} are the seepage velocity vectors of oil, gas, and water, respectively; k_{ro}, k_{rg}, and k_{rw} are the relative permeabilities of oil, gas, and water, respectively; mu_{o}, mu_{g}, and mu_{w} are the viscosities of oil, gas, and water, respectively; and nabla P_{o}, nabla P_{g}, and nabla P_{w} are the pressures of the oil, gas, and water phases, respectively.

[0012] Furthermore, S4 specifically includes the following steps: S401. Divide the overall remaining reservoir reserves obtained in S2 into different regions according to the structural or permeability zones of the reservoir, and compare them with the remaining oil and gas saturation distribution of each region obtained by the streamline simulation method. S402. If the comparison results are not within the preset range, re-examine the input parameters in the material balance method and the streamline simulation method. For the material balance method, check the applicability of the production data or phase equation. For the streamline simulation method, re-evaluate the reservoir parameters or adjust the boundary conditions of the three-dimensional reservoir geological model until the comparison results are within the preset range. Then, the calibrated streamline simulation method results are obtained.

[0013] Furthermore, S5 specifically refers to: S501. Based on the results of the calibrated streamline simulation method, the saturation distribution of residual oil and gas in the intercone zone of the bottom water condensate gas reservoir in different layers and structural regions, as well as the spatial relationship between residual oil and gas and bottom water, are characterized in detail. S502. Based on the distribution of remaining oil and gas, and in conjunction with the reservoir's exploitation technology and economic factors, evaluate the development potential of remaining oil and gas in the intercone zone.

[0014] Secondly, the present invention also discloses a system for characterizing residual hydrocarbons in the intercone zone of bottom-water condensate gas reservoirs, comprising: The data acquisition module is used to acquire production dynamic data and reservoir parameters of bottom water condensate gas reservoirs; The preliminary estimation module is used to make preliminary estimates of the original reserves and overall remaining reserves of the oil reservoir based on the acquired production dynamic data and using the material balance method. The streamline simulation module is used to construct a three-dimensional reservoir geological model based on the acquired reservoir parameters using the streamline simulation method. After setting boundary conditions and initial conditions, streamline simulation calculations are performed to obtain the fluid saturation distribution and streamline orientation at different times. Based on the fluid saturation distribution and streamline at different times, the remaining oil and gas saturation distribution of each region is obtained. The calibration module is used to compare the overall remaining reserves into zones with the remaining oil and gas saturation distribution of each zone. When the differences are large, the reservoir parameters are re-evaluated by the streamline simulation method or the boundary conditions of the three-dimensional reservoir geological model are adjusted; and the calibrated streamline simulation results are obtained. The characterization module is used to characterize the remaining oil and gas distribution based on the calibrated streamline simulation results.

[0015] Thirdly, the present invention also discloses a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the method for characterizing the residual oil and gas in the intercone zone of the bottom water condensate gas reservoir.

[0016] Fourthly, the present invention also discloses a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the method for characterizing the residual oil and gas in the intercone zone of the bottom water condensate gas reservoir.

[0017] Fifthly, the present invention also discloses a computer program product, including a computer program / instruction, which, when executed by a processor, implements the steps of the method for characterizing residual oil and gas in the intercone zone of the bottom water condensate gas reservoir.

[0018] Compared with the prior art, the present invention has the following beneficial technical effects: This invention proposes a method for characterizing the remaining hydrocarbon reserves in the intercone zone of bottom-water condensate gas reservoirs, combining the advantages of the mass balance method and the streamline simulation method. First, the mass balance method is used to perform a preliminary reserve estimation based on the reservoir's production dynamics data, obtaining macroscopic information on the overall remaining hydrocarbon reserves of the reservoir. Then, using the streamline simulation method, a reservoir model is constructed based on detailed reservoir parameters to simulate the seepage process of oil, gas, and water, obtaining the microscopic distribution of the remaining hydrocarbon reserves in the intercone zone. By comparing and calibrating the macroscopic results of the mass balance method with the microscopic results of the streamline simulation method, the macroscopic results of the mass balance method can be used to constrain and verify the streamline simulation method, while the microscopic results of the streamline simulation method can be used to refine and supplement the mass balance method. For example, in the results comparison and calibration step, if the remaining reserves in a certain area estimated by the material balance method do not match the remaining oil and gas saturation distribution in that area obtained by the streamline simulation method, the input parameters of the two methods can be re-examined, thereby improving the accuracy of characterizing the remaining oil and gas in the intercone zone and overcoming the shortcomings of using the material balance method or the streamline simulation method alone in the existing technology. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall process of a method for characterizing residual oil and gas in the intercone zone of a bottom-water condensate gas reservoir according to the present invention. Figure 2 This is a schematic diagram of the preliminary estimation process of the material balance method for characterizing the residual oil and gas in the intercone zone of a bottom water condensate gas reservoir according to the present invention. Figure 3 This is a schematic diagram of the streamline simulation method for constructing a method for characterizing residual oil and gas in the intercone zone of a bottom-water condensate gas reservoir according to the present invention. Figure 4 This is a block diagram of a system for characterizing residual oil and gas in the intercone zone of a bottom-water condensate gas reservoir according to the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the present invention clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention; that is, the described embodiments are only a part of the embodiments of the present invention, and not all of them.

[0021] The components described and illustrated in the accompanying drawings and embodiments of this invention can be arranged and designed in various different configurations. Therefore, the detailed description of the embodiments of the invention provided in the following drawings is not intended to limit the scope of the claimed invention, but merely to illustrate one selected embodiment of the invention. All other embodiments obtained by those skilled in the art based on the accompanying drawings and embodiments of this invention without inventive effort are within the scope of protection of this invention.

[0022] It should be noted that the terms “comprising,” “including,” or any other variations are intended to cover non-exclusive inclusion, such that a process, element, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to the process, element, method, article, or apparatus.

[0023] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0024] Example 1 Please see Figure 1 This invention provides a method for characterizing residual hydrocarbons in the intercone zone of a bottom-water condensate gas reservoir, comprising the following steps: Step S1: Obtain production dynamic data and reservoir parameters; In this step, acquiring production dynamic data includes obtaining daily gas production, daily water production, cumulative gas production, cumulative water production, and reservoir pressure changes over time for each production well in the reservoir; acquiring reservoir parameters includes obtaining spatial distribution data of reservoir permeability, porosity, reservoir thickness, and effective permeability through geological exploration, well logging, and core analysis.

[0025] Step S2: Based on the acquired production dynamic data and reservoir parameters, establish a material balance equation and preliminarily estimate the original reserves and overall remaining reserves of the reservoir using the material balance method. S3. Based on the obtained reservoir parameters, a three-dimensional reservoir geological model is constructed using the streamline simulation method. After setting boundary conditions and initial conditions, streamline simulation calculations are performed to obtain the fluid saturation distribution and streamline orientation at different times. Based on the fluid saturation distribution and streamline at different times, the remaining oil and gas saturation distribution in each region is obtained. S4. After dividing the overall remaining reserves obtained in S2 into zones, compare them with the remaining oil and gas saturation distribution of each zone obtained in S3. If the comparison result is not within the preset range, re-evaluate the reservoir parameters of the streamline simulation method or adjust the boundary conditions of the three-dimensional reservoir geological model until the comparison result is within the preset range. Then, the calibrated streamline simulation method result is obtained. S5. Characterize the remaining oil and gas distribution based on the calibrated streamline simulation results.

[0026] Example 2 like Figure 2 As shown, in S2, the preliminary estimation using the mass balance method specifically includes the following steps: Step S201: Establish a material balance equation. Based on the phase characteristics of the bottom water condensate gas reservoir and the principle of material conservation, establish a material balance equation that includes the phase change term of condensate gas under different pressures and the balance relationship between the intrusion and production of bottom water. In this embodiment, the formula for the mass balance equation is as follows: N = \frac{N_p\left[B_g - \left(R_{si} - R_s\right)B_o\right] + W_pB_w - W_eB_w}{B_g - \left(R_{si} - R_s\right)B_o} Where N represents the original geological reserves, i.e., the original geological reserves of natural gas in the condensate gas reservoir, in cubic meters; N_p represents the cumulative gas production, i.e., the cumulative amount of natural gas produced from the start of production in the reservoir to the current moment, in cubic meters; B_g represents the volume factor of natural gas, i.e., the ratio of the volume of natural gas under reservoir conditions to the volume under standard conditions; R_{si} represents the original dissolved gas-oil ratio, i.e., the amount of natural gas dissolved in a unit volume of oil under original conditions, in cubic meters; R_s represents the current dissolved gas-oil ratio, in cubic meters; B_o represents the volume factor of crude oil; W_p represents the cumulative water production, i.e., the cumulative amount of water produced from the start of production in the reservoir to the current moment, in cubic meters; B_w represents the volume factor of water; and W_e represents the amount of bottom water intrusion, i.e., the amount of bottom water intruding into the reservoir from the start of production in the reservoir to the current moment, in cubic meters.

[0027] Specifically, in its initial state, the original geological reserves of natural gas in the reservoir are N. During the extraction process, the cumulative gas production is N_p. Since dissolved gas is released from the crude oil during extraction, the change in the dissolved gas-oil ratio must be considered. The initial dissolved gas-oil ratio is R_{si}, the current dissolved gas-oil ratio is R_s, and the volume factor of the crude oil is B_o. This means that for every unit volume of crude oil extracted, (R_{si}-R_s)B_o volume of natural gas will be released from the crude oil. Simultaneously, the cumulative water production is W_p, the water volume factor is B_w, and the bottom water intrusion is W_e. The intrusion and extraction of water also need to be considered in the mass balance. According to the law of conservation of mass, the original amount of natural gas N should be equal to the amount of natural gas extracted (including the directly extracted N_p and the amount extracted from crude oil related to crude oil extraction) plus the amount of remaining natural gas. Combining the above relationships, the mass balance equation is derived as follows: N = \frac{N_p\left[B_g -\left(R_{si} - R_s\right)B_o\right] + W_pB_w - W_eB_w}{B_g - \left(R_{si} -R_s\right)B_o}.

[0028] The derivation process of the above mass balance equation is as follows: Step S2011: Obtain the cumulative gas production N_p, cumulative water production W_p, and reservoir pressure variation data over time from the reservoir production database (to calculate parameters such as B_g and R_s at different times); determine parameters such as the original dissolved gas-oil ratio R_{si}, crude oil volume factor B_o, and water volume factor B_w through laboratory analysis and reservoir engineering research. Step S2012: Based on reservoir pressure data, calculate the natural gas volume factor B_g and the current dissolved gas-oil ratio R_s at different times using the equation of state or empirical formula; if monitoring data is available, the intrusion amount W_e of bottom water can be directly obtained; if not, it can be estimated through the transformation of the material balance equation or other reservoir engineering methods. Step S2013: Substitute the obtained and calculated parameters N_p, W_p, B_g, R_{si}, R_s, B_o, B_w, W_e into the material balance equation to calculate the original geological reserves N.

[0029] Step S202: Preliminary reserve estimation. Substitute the obtained production dynamic data into the material balance equation to calculate the original geological reserves and overall remaining reserves of the reservoir.

[0030] Example 3 This section mainly introduces step S3, which involves constructing a three-dimensional reservoir geological model using the streamline simulation method based on the obtained reservoir parameters, and then performing streamline simulation calculations after setting the boundaries and initial conditions.

[0031] like Figure 3 As shown, in S3, the streamline simulation method includes the following construction: Step S301: Construct a reservoir model. Based on the obtained reservoir parameters, construct a three-dimensional reservoir geological model to accurately describe the structural features, lithological distribution, and initial state of fluid distribution of the reservoir. In this embodiment, the formula for the streamline simulation method is as follows: \vec{v}=-\frac{k}{\mu}\nabla P Where v represents the seepage velocity vector, which is the flow velocity of oil in the reservoir, in meters per second; k represents the permeability, which is the ability of the reservoir to allow fluid to pass through, in Darcy or millidarcy; mu represents the viscosity of the fluid, i.e. the viscosity of the oil, in Pascals per second; and nabla P represents the pressure gradient, which is the rate of change of pressure in the reservoir in space, in Pascals per meter.

[0032] Specifically, for single-phase flow (assuming oil phase flow), according to Darcy's law, the flow velocity is directly proportional to the pressure gradient, inversely proportional to the fluid viscosity, and directly proportional to the reservoir permeability; let the oil phase flow velocity be v, the permeability be k, the oil viscosity be mu, and the pressure gradient be nabla P, then we have \vec{v}=-\frac{k}{\mu}\nabla P. Preferably, in practical simulations, for multiphase flow cases, the streamline simulation method requires the use of the three-phase flow equation, the formula of which is as follows: \vec{v}_{o}=-\frac{k_{ro}k}{\mu_{o}}\nabla P_{o} \vec{v}_{g}=-\frac{k_{rg}k}{\mu_{g}}\nabla P_{g} \vec{v}_{w}=-\frac{k_{rw}k}{\mu_{w}}\nabla P_{w} Where vec{v}_{o}, vec{v}_{g}, and vec{v}_{w} are the seepage velocity vectors of oil, gas, and water, respectively; k_{ro}, k_{rg}, and k_{rw} are the relative permeabilities of oil, gas, and water, respectively; mu_{o}, mu_{g}, and mu_{w} are the viscosities of oil, gas, and water, respectively; and nabla P_{o}, nabla P_{g}, and nabla P_{w} are the pressures of the oil, gas, and water phases, respectively.

[0033] Specifically, for multiphase flow, the oil phase flow velocity vo is affected by the relative permeability k_{ro} of the oil phase. This is because, in the presence of multiple phases, the actual flow capacity of the oil phase is the product of the relative permeability and the absolute permeability, so ∂v / ∂o = -∂k_{ro}k}{∂mu / ∂o} P_{o}. Similarly, for the gas phase, the flow velocity ∂v / ∂g = -∂k_{rg}k}{∂mu / ∂g} P_{g}, and for the aqueous phase, the flow velocity ∂v / ∂w = -∂k_{rw}k}{∂mu / ∂w} P_{w}.

[0034] The derivation process of the above single (three) phase seepage equation is as follows: Step S3011: Obtain the reservoir permeability k (permeability value of each grid cell in the three-dimensional model) from the geological model, obtain the viscosity mu_{o}, mu_{g}, and mu_{w} of oil, gas, and water through laboratory measurements, and set the initial pressure nabla P_{o}, nabla P_{g}, and nabla P_{w} of the oil, gas, and water phases according to the initial conditions of the reservoir. Step S3012: Based on the saturation of each phase (initial saturation or saturation gradually calculated from the simulation process), calculate the relative permeability k_{ro}, k_{rg}, and k_{rw} of oil, gas, and water using the relative permeability curve (determined experimentally). Step S3013: Discretize the reservoir model into grid cells within each time step: Step 1: Calculate the pressure gradients nabla P_{o}, nabla P_{g}, and nabla P_{w} within each grid cell; Step 2: Substitute the parameters k, mu_{o}, mu_{g}, mu_{w}, k_{ro}, k_{rg}, k_{rw}, nabla P_{o}, nabla P_{g}, nabla P_{w} into the seepage equation to calculate the seepage vec{v}_{o}, vec{v}_{g}, and vec{v}_{w} of the oil, gas, and water phases; Step 3: Update the saturation and pressure distribution of each phase in each grid cell based on the seepage velocity.

[0035] Repeat the above steps until the simulation terminates.

[0036] Step S302: Set boundary conditions and initial conditions. Set the boundary conditions and initial conditions of the model according to the actual production situation of the reservoir. The boundary conditions further include the boundary type of the reservoir, and the initial conditions further include the initial pressure and initial saturation. Step S303: Streamline simulation calculation. Based on the established reservoir model, boundary conditions and initial conditions, streamline simulation calculation is performed to solve the seepage equation, track the streamline distribution of oil, gas and water in the reservoir, and obtain the fluid saturation distribution and streamline direction at different times.

[0037] Step S4: After dividing the overall remaining reserves obtained by the material balance method into zones, compare them with the regional results obtained by the streamline simulation method. If the differences are large, adjust the parameters. In this step, the results comparison includes Step S401, Regional comparison: The total remaining reserves of the reservoir obtained by the material balance method are divided into different regions according to the structural zoning or permeability zoning of the reservoir, and compared with the remaining oil and gas saturation distribution of each region obtained by the streamline simulation method. Step S402, parameter adjustment and calibration: If there is a large difference in the comparison results and they are not within the preset range, re-examine the input parameters in the material balance method and the streamline simulation method. For the material balance method, check the applicability of the production data or phase equation. For the streamline simulation method, re-evaluate the reservoir parameters or adjust the boundary conditions of the model until the comparison results are within the preset range. Then, the calibrated streamline simulation method results are obtained. Example 4 This section mainly introduces step S5, which characterizes the remaining oil and gas distribution and evaluates the development potential based on the calibrated streamline simulation results.

[0038] In this step, characterizing the distribution of remaining oil and gas includes: Step S501, Detailed Characterization: Based on the calibrated streamline simulation results, the saturation distribution of residual oil and gas in the intercone zone of the bottom water condensate gas reservoir in different layers and structural regions, as well as the spatial relationship between the residual oil and gas and the bottom water, are characterized in detail (for example, a three-dimensional distribution map of the residual oil and gas saturation in the intercone zone is drawn to intuitively show the enrichment areas and distribution characteristics of the residual oil and gas). Step S502, Development Potential Evaluation: Based on the distribution of remaining oil and gas, combined with the reservoir's exploitation technology and economic factors, evaluate the development potential of remaining oil and gas in the intercone zone.

[0039] Example 5 like Figure 4 As shown, the present invention also discloses a system for characterizing residual hydrocarbons in the intercone zone of bottom-water condensate gas reservoirs, comprising: The data acquisition module is used to acquire production dynamic data and reservoir parameters of bottom water condensate gas reservoirs; The preliminary estimation module is used to make preliminary estimates of the original reserves and overall remaining reserves of the oil reservoir based on the acquired production dynamic data and using the material balance method. The streamline simulation module is used to construct a three-dimensional reservoir geological model based on the acquired reservoir parameters using the streamline simulation method. After setting boundary conditions and initial conditions, streamline simulation calculations are performed to obtain the fluid saturation distribution and streamline orientation at different times. Based on the fluid saturation distribution and streamline at different times, the remaining oil and gas saturation distribution of each region is obtained. The calibration module is used to compare the overall remaining reserves into zones with the remaining oil and gas saturation distribution of each zone. When the differences are large, the reservoir parameters are re-evaluated by the streamline simulation method or the boundary conditions of the three-dimensional reservoir geological model are adjusted; and the calibrated streamline simulation results are obtained. The characterization module is used to characterize the remaining oil and gas distribution based on the calibrated streamline simulation results.

[0040] This invention combines two techniques: the mass balance method and the streamline simulation method. First, the mass balance method is used to preliminarily estimate the reservoir's original reserves and overall remaining reserves. Then, the streamline simulation method is used to characterize the distribution of remaining oil and gas in detail. This method can more accurately assess the reservoir's remaining oil and gas resources and improve the reliability of resource evaluation.

[0041] In the construction and calibration of three-dimensional reservoir geological models, a three-dimensional reservoir geological model is constructed based on reservoir parameters obtained from geological exploration, well logging, and core analysis. The model is then calibrated by comparing the overall remaining reserves estimated by the mass balance method with the remaining hydrocarbon saturation distribution in each region obtained by the streamline simulation method. The calibrated three-dimensional reservoir geological model can more realistically reflect the actual situation of the reservoir and improve the accuracy of remaining hydrocarbon prediction.

[0042] In streamline simulation, a three-phase flow equation is used to simulate the multiphase flow characteristics of bottom water condensate gas reservoirs. The application of this multiphase flow equation can more accurately describe the flow behavior of oil, gas, and water in the reservoir, improving the accuracy of streamline simulation.

[0043] Based on the calibrated streamline simulation results, the saturation distribution of remaining oil and gas in different layers and structural regions is characterized in detail. Combined with the reservoir's exploitation technology and economic factors, the development potential of remaining oil and gas in the intercone zone is evaluated. This evaluation can provide a scientific basis for reservoir development decisions, optimize development plans, and improve the reservoir's economic benefits.

[0044] Example 6 This invention also discloses a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the method for characterizing residual oil and gas in the intercone zone of a bottom-water condensate gas reservoir. The memory may include main memory, such as high-speed random access memory, and may also include non-volatile memory, such as at least one disk storage device. The processor, network interface, and memory are interconnected via an internal bus, which may be an industry-standard architecture bus, a peripheral component interconnection standard bus, an extended industry-standard architecture bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. The memory is used to store the program; specifically, the program may include program code, which includes computer operation instructions. The memory may include main memory and non-volatile memory, and provides instructions and data to the processor.

[0045] Example 7 This invention also discloses a computer-readable storage medium storing a computer program. When executed by a processor, the computer program implements the steps of the method for characterizing residual oil and gas in the intercone zone of a bottom-water condensate gas reservoir. Specifically, the computer-readable storage medium includes, but is not limited to, volatile memory and / or non-volatile memory. The volatile memory may include random access memory and / or cache memory, etc. The non-volatile memory may include read-only memory, hard disk, flash memory, optical disk, magnetic disk, etc.

[0046] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, optical storage, etc.) containing computer-usable program code.

[0047] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0048] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0049] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for characterizing residual hydrocarbons in the intercone zone of a bottom-water condensate gas reservoir, characterized in that, Includes the following steps: S1. Obtain production dynamics data and reservoir parameters of bottom water condensate gas reservoirs; S2. Based on the acquired production dynamic data, the original reserves and overall remaining reserves of the reservoir are initially estimated using the material balance method. S3. Based on the obtained reservoir parameters, a three-dimensional reservoir geological model is constructed using the streamline simulation method. After setting boundary conditions and initial conditions, streamline simulation calculations are performed to obtain the fluid saturation distribution and streamline orientation at different times. Based on the fluid saturation distribution and streamline at different times, the remaining oil and gas saturation distribution in each region is obtained. S4. After dividing the overall remaining reserves obtained in S2 into zones, compare them with the remaining oil and gas saturation distribution of each region obtained in S3. If the comparison results are not within the preset range, re-evaluate the reservoir parameters of the streamline simulation method or adjust the boundary conditions of the three-dimensional reservoir geological model to obtain the calibrated streamline simulation method results. S5. Characterize the remaining oil and gas distribution based on the calibrated streamline simulation results.

2. The method for characterizing residual oil and gas in the intercone zone of a bottom-water condensate gas reservoir according to claim 1, characterized in that, In S1, the production dynamic data includes the daily gas production, daily water production, cumulative gas production, cumulative water production, and reservoir pressure change data over time for each production well. The specific process for obtaining reservoir parameters involves acquiring spatial distribution data on reservoir permeability, porosity, reservoir thickness, and effective permeability through geological exploration, well logging, and core analysis.

3. The method for characterizing residual hydrocarbons in the intercone zone of a bottom-water condensate gas reservoir according to claim 1, characterized in that, In S2, the initial reserves and overall remaining reserves of the reservoir are preliminarily estimated using the material balance method, specifically including the following steps: S201. Establish the material balance equation: Based on the phase characteristics of the bottom water condensate gas reservoir and the principle of material conservation, establish a material balance equation that includes the phase change term of condensate gas under different pressures, as well as the balance relationship between the intrusion and production of bottom water. S202. Preliminary Reserve Estimation: Substitute the acquired production dynamic data into the material balance equation to calculate the original geological reserves and overall remaining reserves of the reservoir. The formula for the mass balance equation is as follows: N = \frac{N_p\left[B_g - \left(R_{si} - R_s\right)B_o\right] + W_pB_w - W_eB_w}{B_g - \left(R_{si} - R_s\right)B_o} Where N represents the original geological reserves; N_p represents the cumulative gas production; B_g represents the volume factor of natural gas; R_{si} represents the original dissolved gas-oil ratio; R_s represents the current dissolved gas-oil ratio; B_o represents the volume factor of crude oil; W_p represents the cumulative water production; B_w represents the volume factor of water; and W_e represents the amount of bottom water intrusion.

4. The method for characterizing residual oil and gas in the intercone zone of a bottom-water condensate gas reservoir according to claim 1, characterized in that, S3 specifically includes the following steps: S301. Construct a three-dimensional reservoir geological model based on the reservoir parameters obtained in S1. The three-dimensional reservoir geological model can describe the structural features, lithological distribution, and initial state of fluid distribution of the reservoir. S302. Set the boundary conditions and initial conditions of the three-dimensional reservoir geological model according to the actual production situation of the reservoir; the boundary conditions include the boundary type of the reservoir, and the initial conditions include the initial pressure and the initial saturation. S303. Based on the established three-dimensional reservoir geological model, boundary conditions, and initial conditions, streamline simulation calculations are performed to solve the seepage equation, track the streamline distribution of oil, gas, and water in the reservoir, and obtain the fluid saturation distribution and streamline direction at different times.

5. A method for characterizing residual oil and gas in the intercone zone of a bottom-water condensate gas reservoir according to claim 4, characterized in that: The formula for the streamline simulation method is as follows: \vec{v}=-\frac{k}{\mu}\nabla P Where v represents the seepage velocity vector; k represents the permeability; mu represents the fluid viscosity; and P represents the pressure gradient. In practical simulations, the streamline simulation method uses a three-phase flow equation for multiphase flow. The formula for the three-phase flow equation is as follows: \vec{v}_{o}=-\frac{k_{ro}k}{\mu_{o}}\nabla P_{o} \vec{v}_{g}=-\frac{k_{rg}k}{\mu_{g}}\nabla P_{g} \vec{v}_{w}=-\frac{k_{rw}k}{\mu_{w}}\nabla P_{w} Where vec{v}_{o}, vec{v}_{g}, and vec{v}_{w} are the seepage velocity vectors of oil, gas, and water, respectively; k_{ro}, k_{rg}, and k_{rw} are the relative permeabilities of oil, gas, and water, respectively; mu_{o}, mu_{g}, and mu_{w} are the viscosities of oil, gas, and water, respectively; and nabla P_{o}, nabla P_{g}, and nabla P_{w} are the pressures of the oil, gas, and water phases, respectively.

6. The method for characterizing residual oil and gas in the intercone zone of a bottom-water condensate gas reservoir according to claim 3, characterized in that: S4 specifically includes the following steps: S401. Divide the overall remaining reservoir reserves obtained in S2 into different regions according to the structural or permeability zones of the reservoir, and compare them with the remaining oil and gas saturation distribution of each region obtained by the streamline simulation method. S402. If the comparison results are not within the preset range, re-examine the input parameters in the material balance method and the streamline simulation method. For the material balance method, check the applicability of the production data or phase equation. For the streamline simulation method, re-evaluate the reservoir parameters or adjust the boundary conditions of the three-dimensional reservoir geological model until the comparison results are within the preset range. Then, the calibrated streamline simulation method results are obtained. S5 specifically refers to: S501. Based on the results of the calibrated streamline simulation method, the saturation distribution of residual oil and gas in the intercone zone of the bottom water condensate gas reservoir in different layers and structural regions, as well as the spatial relationship between residual oil and gas and bottom water, are characterized in detail. S502. Based on the distribution of remaining oil and gas, and in conjunction with the reservoir's exploitation technology and economic factors, evaluate the development potential of remaining oil and gas in the intercone zone.

7. A system for characterizing residual hydrocarbons in the intercone zone of a bottom-water condensate gas reservoir, characterized in that, include: The data acquisition module is used to acquire production dynamic data and reservoir parameters of bottom water condensate gas reservoirs; The preliminary estimation module is used to make preliminary estimates of the original reserves and overall remaining reserves of the oil reservoir based on the acquired production dynamic data and using the material balance method. The streamline simulation module is used to construct a three-dimensional reservoir geological model based on the acquired reservoir parameters using the streamline simulation method. After setting boundary conditions and initial conditions, streamline simulation calculations are performed to obtain the fluid saturation distribution and streamline orientation at different times. Based on the fluid saturation distribution and streamline at different times, the remaining oil and gas saturation distribution of each region is obtained. The calibration module is used to compare the overall remaining reserves into zones with the remaining oil and gas saturation distribution of each zone. When the differences are large, the reservoir parameters are re-evaluated by the streamline simulation method or the boundary conditions of the three-dimensional reservoir geological model are adjusted to obtain the calibrated streamline simulation method results. The characterization module is used to characterize the remaining oil and gas distribution based on the calibrated streamline simulation results.

8. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method for characterizing the residual oil and gas in the intercone zone of a bottom water condensate gas reservoir as described in any one of claims 1 to 6.

9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the method for characterizing the residual oil and gas in the intercone zone of the bottom water condensate gas reservoir as described in any one of claims 1 to 6.

10. A computer program product comprising a computer program / instructions, characterized in that, When the computer program / instruction is executed by the processor, it implements the steps of the method for characterizing the residual oil and gas in the intercone zone of the bottom water condensate gas reservoir as described in any one of claims 1-6.

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