CN117993327B

CN117993327B - Reservoir simulation method, device, equipment and medium for seepage type natural gas hydrate

Info

Publication number: CN117993327B
Application number: CN202410354049.0A
Authority: CN
Inventors: 张伟; 关进安; 刘鹏奇; 季春生; 王梦荷; 袁胜; 王阔; 莫仕林; 王飞飞; 陈炜; 王力峰
Original assignee: Guangzhou Marine Geological Survey Sanya Institute Of South China Sea Geology
Current assignee: Guangzhou Marine Geological Survey Sanya Institute Of South China Sea Geology
Priority date: 2024-03-27
Filing date: 2024-03-27
Publication date: 2024-06-11
Anticipated expiration: 2044-03-27
Also published as: CN117993327A

Abstract

The application discloses a reservoir simulation method, device, equipment and medium of a leakage type natural gas hydrate, and relates to the technical field of natural gas hydrate exploration, wherein the method comprises the following steps: constructing a reservoir model of a leakage type natural gas hydrate gas chimney and a block flow; configuring reservoir parameters for a reservoir model; the reservoir parameters comprise reservoir porosity parameters, a relation model of natural gas hydrate gas and depth, a transportation model and a reaction model of natural gas hydrate, a reservoir sediment particle and water characteristic curve, reservoir permeability and reservoir tensile strength; and carrying out numerical simulation on the natural gas hydrate by using a reservoir model after configuration of reservoir parameters. By configuring various reservoir parameters for the reservoir model, the application can accurately simulate and characterize the formation evolution process and dynamic mechanism of the reservoir formation of the leakage type natural gas hydrate formed by the gas chimney-block flow, and can simulate the real situation of the natural gas hydrate reservoir.

Description

Reservoir simulation method, device, equipment and medium for seepage type natural gas hydrate

Technical Field

The application relates to the technical field of natural gas hydrate exploration, in particular to a reservoir simulation method, device, equipment and medium of a leakage type natural gas hydrate.

Background

For the exploration scheme of natural gas hydrate, most of experimental simulation in the prior art aims at reservoir parameter change in the exploitation process of a natural gas hydrate reservoir, or adopts a physical simulation means to simulate reservoir formation change, other modules such as sediment preparation, liquid supply, gas supply, temperature and pressure control required by hydrate reservoir formation and the like are required to be prepared before simulation, and the actual situation of the in-situ stratum cannot be truly reflected because of more parameters of the reservoir under manual control.

Disclosure of Invention

The embodiment of the application mainly aims to provide a reservoir simulation method, device, equipment and medium for seepage type natural gas hydrate, so as to truly and accurately simulate the reservoir condition of the natural gas hydrate.

To achieve the above object, an aspect of an embodiment of the present application provides a reservoir simulation method of a leaky natural gas hydrate, the method including:

constructing a reservoir model of a leakage type natural gas hydrate gas chimney and a block flow;

Configuring reservoir parameters for the reservoir model; the reservoir parameters comprise reservoir porosity parameters, a relation model of natural gas hydrate gas and depth, a transportation model and a reaction model of natural gas hydrate, a reservoir sediment particle and water characteristic curve, reservoir permeability and reservoir tensile strength;

And carrying out numerical simulation on the natural gas hydrate by using the reservoir model after the reservoir parameters are configured.

In some embodiments, the step of obtaining the reservoir porosity parameter comprises:

determining a porosity parameter in the absence of natural gas hydrate in the reservoir as an initial porosity;

The expression of the initial porosity is:

；

Wherein, Representing the initial porosity, z representing depth,/>Representing the porosity of the surface layer deposit;

Determining a porosity parameter of a reservoir after filling natural gas hydrate as the reservoir porosity parameter;

the expression of the reservoir porosity parameter is:

；

Wherein, Representing the reservoir porosity parameter,/>Representing the saturation of the natural gas hydrate.

In some embodiments, the step of obtaining the natural gas hydrate gas versus depth model comprises:

fitting a relationship between methane gas concentration and depth as the relationship model;

The relation model is as follows:

；

Wherein, Indicating the methane gas concentration, z indicating the depth.

In some embodiments, the step of obtaining a transport model and a reaction model of the natural gas hydrate comprises:

determining the transport model from the gradient differences of the fugacity under local thermodynamic and equilibrium conditions:

The transportation model is as follows:

；

Wherein, Representing the transport model,/>Representing the kinetic coefficient of the hydrate reaction,/>The value of the temperature is indicated,Represents equilibrium temperature,/>Representing reservoir temperature,/>Representing the reservoir porosity parameter,/>Representing the local thermodynamic conditions,/>Representing the equilibrium condition;

Determining the reaction model as:

；

Wherein, Representing the reaction model,/>Time is expressed by/>Representing the porosity of the reservoir,/>Representing saturation of natural gas hydrate,/>Represents the density of natural gas hydrate,/>Represents the molar mass of the natural gas hydrate.

In some embodiments, the step of obtaining the reservoir sediment particle-to-water characteristic curve comprises:

measuring and obtaining a characteristic curve of the reservoir sediment particles and water by using a normalization method;

The expression of the reservoir sediment particle and water characteristic curve is as follows:

；

Wherein S _e represents the effective fluid saturation; s _l represents liquid saturation, S _g represents gas saturation; s _li represents the initial non-reducible liquid saturation, S _gi represents the initial non-reducible gas saturation.

In some embodiments, the step of obtaining the reservoir permeability comprises:

Determining the reservoir permeability according to a permeability calculation;

the permeability is calculated as:

；

Wherein, Representing the reservoir permeability,/>Indicating the intrinsic permeability in the absence of natural gas hydrate in the reservoir,/>Represents the saturation of natural gas hydrate;

The step of obtaining the reservoir tensile strength comprises:

determining the reservoir tensile strength according to a pore pressure relationship;

the pore pressure relationship is:

S_v=P_c+P_l-T_sp-σ_h>0；

Wherein S _v represents the intra-pore pressure difference criterion term, P _c represents capillary pressure, P _l represents pore liquid phase pressure, T _sp represents the reservoir tensile strength, σ _h represents horizontal stress.

In some embodiments, the numerically modeling natural gas hydrate using the reservoir model after configuring the reservoir parameters comprises:

And performing at least one of natural gas hydrate dynamic formation process simulation, natural gas hydrate formation evolution process simulation, natural gas hydrate reservoir force imbalance simulation, reservoir change simulation by different deposition scenes, hydrate distribution simulation or geological time hydrate formation evolution simulation by using the reservoir model after configuration of the reservoir parameters.

To achieve the above object, another aspect of the embodiments of the present application provides a reservoir simulation apparatus for leaky natural gas hydrate, the apparatus comprising:

the model building unit is used for building a reservoir model of the leakage type natural gas hydrate gas chimney and the block flow;

A parameter configuration unit for configuring reservoir parameters for the reservoir model; the reservoir parameters comprise reservoir porosity parameters, a relation model of natural gas hydrate gas and depth, a transportation model and a reaction model of natural gas hydrate, a reservoir sediment particle and water characteristic curve, reservoir permeability and reservoir tensile strength;

And the numerical simulation unit is used for performing numerical simulation on the natural gas hydrate by using the reservoir model after the reservoir parameters are configured.

To achieve the above object, another aspect of the embodiments of the present application provides an electronic device, which includes a memory storing a computer program and a processor implementing the above method when executing the computer program.

To achieve the above object, another aspect of the embodiments of the present application proposes a computer-readable storage medium storing a computer program which, when executed by a processor, implements the above-mentioned method.

The embodiment of the application at least comprises the following beneficial effects:

The application constructs a reservoir model of a leakage type natural gas hydrate gas chimney and a block flow; configuring reservoir parameters for a reservoir model; the reservoir parameters comprise reservoir porosity parameters, a relation model of natural gas hydrate gas and depth, a transportation model and a reaction model of natural gas hydrate, a reservoir sediment particle and water characteristic curve, reservoir permeability and reservoir tensile strength; and carrying out numerical simulation on the natural gas hydrate by using a reservoir model after configuration of reservoir parameters. By configuring various reservoir parameters for the reservoir model, the application can accurately simulate and characterize the formation evolution process and the dynamic mechanism of the reservoir formation of the leakage type natural gas hydrate formed by the gas chimney-block flow, and can reveal the phase change rule in the formation process of the leakage type hydrate under the geological structure and control the influence factors. The history of the enrichment and accumulation evolution of the natural gas hydrate is revealed from the time perspective, the characteristics of a leakage type natural gas hydrate reservoir and the natural gas hydrate accumulation and distribution rules can be mastered, and the exploration and development of the natural gas hydrate can be guided.

Drawings

FIG. 1 is a schematic flow chart of a reservoir simulation method for a leaky natural gas hydrate according to an embodiment of the application;

FIG. 2 is a schematic diagram of a reservoir model according to an embodiment of the present application;

FIG. 3 is a graph of parameters used by a reservoir model according to an embodiment of the present application;

FIG. 4 is a schematic diagram of simulation parameters of a natural gas hydrate formation evolution process according to an embodiment of the present application;

FIG. 5 is a schematic diagram of simulation parameters of natural gas hydrate reservoir force imbalance provided in an embodiment of the present application;

FIG. 6 is a schematic diagram of simulated reservoir variation and hydrate distribution parameters for different deposition scenarios according to an embodiment of the present application;

FIG. 7 is a graph of six geological scenarios and corresponding parameters of a natural gas hydrate provided by an embodiment of the present application;

FIG. 8 is a schematic diagram of simulated parameters of geologic time hydrate formation evolution according to an embodiment of the present application;

FIG. 9 is a schematic diagram of a reservoir simulator of a leaky natural gas hydrate according to an embodiment of the application;

Fig. 10 is a schematic diagram of a hardware structure of an electronic device according to an embodiment of the present application.

Detailed Description

The present application will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present application more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the application. When the following description refers to the accompanying drawings, the same numbers in different drawings refer to the same or similar elements, unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with embodiments of the application, but are merely examples of apparatuses and methods consistent with aspects of embodiments of the application as detailed in the accompanying claims.

It is to be understood that the terms "first," "second," and the like, as used herein, may be used to describe various concepts, but are not limited by these terms unless otherwise specified. These terms are only used to distinguish one concept from another. For example, the first information may also be referred to as second information, and similarly, the second information may also be referred to as first information, without departing from the scope of embodiments of the present application. The words "if", as used herein, may be interpreted as "at … …" or "at … …" or "in response to a determination", depending on the context.

The terms "at least one", "a plurality", "each", "any" and the like as used herein, at least one includes one, two or more, a plurality includes two or more, each means each of the corresponding plurality, and any one means any of the plurality.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of the application only and is not intended to be limiting of the application.

Before describing embodiments of the present application in detail, some terms and expressions which may be involved in the embodiments of the present application will be described first, and the terms and expressions which may be involved in the embodiments of the present application are applicable to the following explanation:

Natural gas hydrate: the solid substance is a solid substance similar to ice formed by combining water molecules and small-molecule hydrocarbon such as methane under the conditions of low temperature and high pressure, and can be ignited at normal temperature and normal pressure, so the solid substance is commonly called as 'combustible ice'.

A seafloor-like reflective layer: formations containing natural gas hydrates often exhibit a strong amplitude continuous reflection in seismic reflection profiles, approximately parallel to the sea floor reflection, and are therefore called sea floor reflections (Bottom Simulating Reflector, BSR for short), which generally represent the bottom boundary of the hydrate stability domain. Foreign research results show that the bottom boundary of the hydrate stability domain represents a specific pressure and temperature surface. Because the pressure changes in the subsurface formation are not large, but the temperature changes are large (there is a gradient of temperature), the heave changes in the seabed will cause the heave changes in the isothermal surface in the formation, thereby forming the bottom boundary of the hydrate stability zone. Thus, the BSR is approximately parallel to the seabed terrain, but is either diagonal to the formation level (when the formation level is diagonal to the seabed) or parallel (when the formation level is parallel to the seabed).

Natural gas hydrate stability domain: abbreviated as "Stability Zone", (GAS HYDRATE Stability Zone, GHSZ). The relevant video views all refer to the presence of a specific region of the subsurface where temperature and pressure are within the thermodynamically stable range of natural gas hydrate formation. It characterizes the maximum range of possible hydrate formation.

Mud is held in the daway: the bottom wall structure refers to a dome or mushroom-like structure formed by flowing high-plasticity low-viscosity rocks (such as rock salt, gypsum or mudstone, etc.) with smaller density upward, arching or even penetrating an overburden.

And (3) an air chimney: is a chimney-like abnormal reflection which is shown on a seismic reflection section after the stratum contains gas, and usually shows a seismic fuzzy zone or a blank zone, and a gas chimney is a dominant channel for migration of gas-containing fluid in the deep part of the stratum and consists of a series of microcracks or small faults.

Cold spring: is mainly composed of water, hydrocarbon table substances (natural gas and petroleum), hydrogen sulfide or carbon dioxide, and is transported and discharged from a sediment under the influence of pressure gradient. A fluid having a temperature similar to that of sea water and a certain flow rate.

Block flow: mass Transport Deposits (MTDs) refers to the occurrence of large scale gravity flow due to gravity destabilization in a deep sea environment, thereby producing large scale composite depositions including 3 gravity flow deposition types of slip, slump and debris flow deposition.

Natural gas hydrate (the embodiment of the application is called as hydrate for short), commonly called as 'combustible ice', is a crystal compound formed by natural gas molecules (mainly methane) and water molecules under the conditions of high pressure and low temperature. Hydrates are mainly distributed in land permanent frozen earth zones and land slopes and deep sea basins with water depths of more than 300-500 meters, and are found or presumed to exist in more than 200 places worldwide. The hydrate has the characteristics of wide distribution, large resource amount, high energy density, small environmental pollution after combustion and the like, and is recognized as a future alternative energy source.

The Liu Po area of the global continental marginal sea area often develops various fluid-conducting geological structures such as a mud bottom, a gas chimney, faults (including co-sedimentary faults), a fluid pipeline, an unconformity surface, a permeable sandstone layer and the like due to construction activities, the submarine sediment of the area has sufficient thickness, rich organic carbon content and superior hydrocarbon production conditions, biological methane produced by shallow organic matters and heat methane produced by deep hydrocarbon source rocks flow into a shallow surface layer, and a constructed leakage type water-containing compound reservoir is formed under a proper thermodynamic environment. The visual hydrate core taken out by drilling is in various output states such as block, lamellar, tubercular, pulse and the like, is cemented in the silt clay in a crack filling mode, and has the reservoir forming characteristics of concentrated distribution and high abundance.

The exploration data find out that submarine flow accompanying phenomena such as submarine pits, hillocks, cold springs, accompanying biological communities and the like which indicate the possible existence of leaky hydrates often develop gas vertical migration leakage channels such as mud bottom, gas chimneys, faults and the like at the lower part of a seepage type hydrate stability region, and abundant methane and other gases enter the hydrate stability region through the migration leakage channels, so that potential gas buoyancy pressure, gas-containing thermal fluid activity, pore water change, biochemical activity and the like can cause lithology or physical property change of a hydrate reservoir, hydrate (solid state), methane and other gases (gas state) exist at the same time, and the multiphase states such as pore water (liquid state) are mutually converted or coexist, so that the formation of a seepage type hydrate system is accompanied by complicated geological, physical and chemical changes. The complex physical and chemical change parts can be simulated and observed through some physical simulation tests, but physical simulation is difficult to develop through approaching to actual geological conditions, the formation process and control factors of a leakage type hydrate reservoir are difficult to find out through observation, and the long-time dynamic reservoir formation process of the reconstructed hydrate is difficult to realize. Thus, problems that still exist in current research on leaky hydrate reservoir formation evolution and hydrate dynamic reservoir distribution include:

(1) The thermodynamic characteristics of multiphase transformation such as gas (gas) such as methane and the like, pore water (liquid) and the like in the stable domain of the leaked hydrate, the three-phase coexistence mechanism, the development of a hydrate enriched dessert ring layer, the back operation rules and the like are not yet ascertained;

(2) The influence of dynamic mechanism and space discontinuous distribution under the influence of the characteristics of geological structures after the gas such as methane in a seepage type hydrate system enters a stable domain is not yet explored;

(3) The evolution, occurrence and distribution of leaky hydrates, association with current environments, etc. over long geological cycle history have not been demonstrated by examples.

In order to intuitively grasp and understand the storage evolution and the reservoir formation characteristics and mechanisms of the typical-structure leakage type hydrate, the reservoir formation and the hydrate reservoir formation conditions in a hydrate system under actual geological conditions need to be simulated, the influences of factors such as submarine sediment, sea level lifting and gas production characteristics and the like are comprehensively considered, a corresponding flow-force-thermal coupling geological-geophysical-reaction kinetic model is established, the space-time matching characteristics and the enrichment rules of regional hydrates for a period of history are discussed, and the basic theoretical problems about how the leakage system controls the growth of the hydrate reservoir formation and the dynamic reservoir formation evolution and the spatial distribution of the hydrates are explained and definitely.

The prior art scheme is as follows: considering the influence of factors such as submarine sediment, sea level elevation and gas production characteristics, the space-time matching characteristics and enrichment rules of the hydrate in the research area for a long time are discussed, and the basic theoretical problem of how to control the growth of the hydrate reservoir by a seepage system is explained and definitely. The method comprises the steps of inputting basic stratum sequence, gas-liquid-solid properties, a sedimentation force field, a thermal field, a Liu Poou working condition and space-time fitting parameters, inputting the deposition rate of a shallow surface soil bed of a research area, the variation of sea level, the internal and external permeability difference condition of a representative seepage structure such as a gas chimney and the like, the local temperature field, soil mass properties and the like, calculating the phase balance stable area and the content of dissolved methane, then starting to calculate the evolution process of a seepage type hydrate system along with time, and calculating the stratum tension value and judging the stratum fracture criterion according to the set logging seismic wave value and the minimum principal stress principle. Finally, the present embodiment discusses the estimation of various possibilities of the evolution history of the local whole leaky hydrate system by assuming that there are possible geological scenarios such as different contents of hydrate, different permeability-kinetic reaction coefficient influences, gas supply flux influences, and the like, and finally obtaining the final occurrence and distribution rule.

Prior art solutions related to the present application:

(1) The natural gas hydrate reservoir in-situ property parameter simulation test system (application number: CN 201510613624.5) comprises a simulation chamber filled with filler, wherein the simulation chamber is connected with a temperature measurement unit, a temperature control unit, a resistivity measurement unit, a permeability measurement unit, an acoustic wave measurement unit and a gas volume calibration chamber, the pressure control unit is connected with the simulation chamber and the gas volume calibration chamber, a temperature sensor and a pressure sensor are arranged in the gas volume calibration chamber, and the temperature sensor and the pressure sensor of the temperature measurement unit, the temperature control unit, the pressure control unit, the resistivity measurement unit, the permeability measurement unit, the acoustic wave measurement unit and the gas volume calibration chamber are connected with a data processing and signal management and control unit. The method can be used for obtaining the association relation between the nature parameters of the natural gas hydrate reservoir such as the porosity, the permeability, the hydrate saturation and the like of the simulated natural gas hydrate reservoir and the geophysical parameters such as sound waves, the resistivity and the like.

(2) An experimental device and a method (application number: CN 202010502477.5) for simulating the formation of marine leakage type natural gas hydrate based on a geotechnical centrifuge, wherein the experimental device comprises the geotechnical centrifuge, a hanging basket assembly and a radial arm carrying device assembly; the hanging basket assembly is hinged with one end of the spiral arm of the geotechnical centrifuge through a hanging basket connecting shaft, and comprises a soil body sample containing natural gas hydrate, a fixing member thereof, a high-pressure bin, a water bath jacket and the like, and the spiral arm carrying device assembly is fixedly arranged on the spiral arm of the geotechnical centrifuge and is used for realizing temperature control, air source supply and data acquisition of hydrate formation. The device and the method simulate the gravity field by utilizing the centrifugal acceleration generated by the high-speed rotation of the centrifugal machine in a laboratory to improve the buoyancy, realize the rapid and efficient simulation of the natural gas hydrate storage process under the condition of gas leakage of buoyancy control on the premise of not changing the gas flux, skillfully avoid the limitation of the conventional gas micro-flux supply technology, and enable the leakage type natural gas hydrate storage process to be closer to the actual condition of the natural world.

(3) The device and the method for simulating the rule of influence of the activities of the bottom wall on the hydrate reservoir (application number: CN 202110378099.9) comprise a bottom wall invasion reaction kettle and a simulation accessory, wherein the bottom wall invasion reaction kettle is used for simulating the overburden stratum pressure born by a submarine stratum, simulating the natural gas hydrate reservoir temperature and pressure condition, preparing a natural gas hydrate reservoir sample and simulating the invasion of bottom wall substances, and the simulation accessory comprises a low-temperature control module, a gas supply module, a liquid supply module, a bottom wall fluid preparation and supply module, an effective stress loading module and the like; the simulation of the hydrate formation process under the seabed in-situ condition is realized through the special design of the reaction kettle and the fluid preparation and supply module for the invasion of the bottom wall, the simulation of the influence of the invasion process of the bottom wall on the spatial distribution of the saturation of the hydrate in the hydrate reservoir, the simulation of the invasion boundary of the bottom wall and the control law of the macro physical properties of the hydrate reservoir and the like, and a basic technical means is provided for quantitatively describing the relationship between the activities of the bottom wall and the dynamic formation of the hydrate.

Drawbacks of the prior art include:

Firstly, most experimental simulation aims at reservoir parameter change in the exploitation process of a hydrate reservoir, or adopts a physical simulation means to simulate reservoir formation change, other modules such as sediment preparation, liquid supply, gas supply, temperature and pressure control required by hydrate reservoir formation and the like are required to be prepared before simulation, and the actual situation of an in-situ stratum cannot be truly reflected due to more factors of manually controlling reservoir parameters;

Secondly, the influence of factors such as actual submarine deposition, sea level lifting and gas production characteristics on hydrate reservoir formation cannot be simulated at present by experimental simulation, most numerical simulation adopts mature commercial software, codes are packaged, and functions cannot be modified according to research requirements;

Thirdly, the physical experiment simulation device is limited in size and limited in simulation scale, and the spatial distribution of the whole natural gas hydrate reservoir and the hydrate in the research area cannot be simulated under actual geological conditions;

fourthly, the dynamic quantitative analysis leakage system can not be used for controlling the change of a hydrate reservoir and the change of the dynamic reservoir evolution and the spatial distribution of the hydrate from the long geological time, and the stratum force field change and the sediment physical unbalance condition with large space and long time scale can not be analyzed.

Therefore, in order to explore the formation evolution of a reservoir and the dynamic formation, distribution and evolution characteristics and mechanisms of a hydrate in a geological background area of a gas leakage structure of a submarine shallow surface layer leakage type natural gas hydrate system, a technical reference is provided for the theoretical research and resource evaluation of the natural gas hydrate formation, and the application aims to comprise:

(1) The method comprises the steps of finding out the stratum force field evolution process of a gas chimney-block flow (MTDs) geological system under the background of basin leakage structure, discussing the influence of structures such as a gas chimney structure, a block flow and the like on a leakage type natural gas hydrate reservoir, and revealing the evolution process of the leakage type hydrate reservoir formation mechanism and a geological history period;

(2) Starting from the related view angles of a hydrate gas source, a conductor system, a stable domain, a block flow, rock and soil properties and the like, a one-dimensional dynamic reaction dynamics model of a hydrate system flow-force-thermal coupling geology-geophysics-dynamics which accords with actual geological conditions is established to simulate and reproduce the typical seepage type natural gas hydrate dynamic reservoir forming process and spatial distribution.

The embodiment of the application provides a reservoir simulation method, device, equipment and medium of leakage type natural gas hydrate. The scheme is that a reservoir model of a leakage type natural gas hydrate gas chimney and a block flow is constructed; configuring reservoir parameters for a reservoir model; the reservoir parameters comprise reservoir porosity parameters, a relation model of natural gas hydrate gas and depth, a transportation model and a reaction model of natural gas hydrate, a reservoir sediment particle and water characteristic curve, reservoir permeability and reservoir tensile strength; and carrying out numerical simulation on the natural gas hydrate by using a reservoir model after configuration of reservoir parameters. By configuring various reservoir parameters for the reservoir model, the application can accurately simulate and characterize the formation evolution process and the dynamic mechanism of the reservoir formation of the leakage type natural gas hydrate formed by the gas chimney-block flow, and can reveal the phase change rule in the formation process of the leakage type hydrate under the geological structure and control the influence factors. The history of the enrichment and accumulation evolution of the natural gas hydrate is revealed from the time perspective, the characteristics of a leakage type natural gas hydrate reservoir and the natural gas hydrate accumulation and distribution rules can be mastered, and the exploration and development of the natural gas hydrate can be guided.

The embodiment of the application provides a reservoir simulation method of a leakage type natural gas hydrate, and relates to the technical field of natural gas hydrate exploration. The reservoir simulation method provided by the embodiment of the application can be applied to a terminal, a server and software running in the terminal or the server. In some embodiments, the terminal may be, but is not limited to, a smart phone, a tablet computer, a notebook computer, a desktop computer, a smart speaker, a smart watch, a vehicle-mounted terminal, and the like; the server side can be configured as an independent physical server, a server cluster or a distributed system formed by a plurality of physical servers, and can be configured as a cloud server for providing cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, CDNs, basic cloud computing services such as big data and artificial intelligence platforms, and the server can also be a node server in a blockchain network; the software may be an application or the like that implements a reservoir simulation method, but is not limited to the above.

The application is operational with numerous general purpose or special purpose computer system environments or configurations. For example: personal computers, server computers, hand-held or portable devices, tablet devices, multiprocessor systems, microprocessor-based systems, set top boxes, programmable consumer electronics, network PCs, minicomputers, mainframe computers, distributed computing environments that include any of the above systems or devices, and the like. The application may be described in the general context of computer-executable instructions, such as program modules, being executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. The application may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote computer storage media including memory storage devices.

As an alternative implementation manner, the operation configuration of the embodiment of the present application is as follows:

the device comprises: a computer capable of running MATLAB software, the running hardware environment being at least: tenth generation Intel Rui 3 processor 2.6GHz,8G memory, geFore GTX1660Ti video card, 500G hard disk.

And (2) mounting: the running software environment is Windows 10 operating system, office software, MATLAB R2007 and above version software. In the embodiment of the application, a formula algorithm in a principle determined in the following steps is written into MATLAB software, parameters are debugged, and a running program starts simulation.

Referring to fig. 1, an embodiment of the present application provides a reservoir simulation method of leaky natural gas hydrate, which may include, but is not limited to, S100 to S120, specifically as follows:

s100: and constructing a reservoir model of the leakage type natural gas hydrate gas chimney and the block flow.

In particular, the deposition evolution is mainly controlled by sea level changes, which are closely related to the back rotation of the ice stage, which exposes the land frame again to erosion, and a large amount of land source chips are carried into the sea along with the river, and the sea level changes and the deposition speed determine the change of the seabed position. With various deposition processes, the seafloor may accumulate debris particles to form a porous media deposit. The sediment grain size and the distribution of the seabed skeleton tend to be in a chaotic state, particularly affected by the bulk flow (MTDs). In order to simplify the processing of abnormal reservoirs, the embodiment can explain the seismic profile data, combine the drilling and logging data, and establish a gas chimney-block flow leakage type natural gas hydrate reservoir geological model, namely a reservoir model (the structural schematic diagram of the reservoir model can be referred to as fig. 2, wherein a is an actual seismic profile of a research area, b is a geological pattern diagram of a leakage type natural gas hydrate gas chimney-block flow reservoir system, and c is a block flow structure diagram), and further determine each reservoir parameter of the reservoir model.

S110: configuring reservoir parameters for the reservoir model; the reservoir parameters comprise reservoir porosity parameters, a relation model of natural gas hydrate gas and depth, a transportation model and a reaction model of natural gas hydrate, a reservoir sediment particle and water characteristic curve, reservoir permeability and reservoir tensile strength.

Specifically, the embodiment configures various reservoir parameters for the established reservoir model, so that the reservoir model can truly and accurately reflect the real situation of the natural gas hydrate reservoir.

Further, the steps of acquiring each reservoir parameter are described as including S111 to S116, where each step S111 to S116 may be executed in any order or simultaneously executed in multiple steps, and the embodiment is not limited to a specific execution order.

S111: the step of obtaining the reservoir porosity parameter comprises:

The expression of the initial porosity is:

；

the expression of the reservoir porosity parameter is:

；

In particular, the most important parameter for leaky hydrate formation and occurrence is the hydrate reservoir porosity parameter.

(1) In reservoirs where natural gas hydrates are not present, initial porosity is measured with in situ dataThe expression of which with depth z (mbsf, depth below the sea floor in meters) is:

(R²=0.2046),(1)

Where Φ _t is the porosity of the surface layer deposit.

(2) After filling natural gas hydrate in reservoir sediment pores, correspondingly modified reservoir porosityThe fitting formula varies as:

,(2)

Wherein S _h is the saturation of the natural gas hydrate.

S112: the step of obtaining the natural gas hydrate gas-depth relationship model comprises the following steps:

The relation model is as follows:

；

Wherein, Indicating the methane gas concentration, z indicating the depth.

Specifically, under the gas chimney leakage transport structure, along with the continuous reaction of natural gas hydrate, a process of gradually rarefaction and even extinction of free gas is inevitably present, a phase equilibrium curve of local methane in a dissolved state and a free state is calculated through a thermodynamic state, the vertical distribution state of the hydrate is compared, and the condition that the methane supply of a stable lower layer of the hydrate is sufficient is assumed, and the hydrate reaction is in progress; while the upper-stage surplus methane is completely converted into hydrate, only two phases of hydrate and liquid water are stored in local pores.

The initial fit methane concentration n _diss (mmol/kg) versus depth z (mbsf) is given by:

,(3)

s113: the step of obtaining the transportation model and the reaction model of the natural gas hydrate comprises the following steps:

The transportation model is as follows:

；

Determining the reaction model as:

；

In particular, hydrate formation and decomposition reactions for individual formation cross sections are affected by their own kinetics, temperature, pressure and reaction space, typically one water molecule combines with 5.76 methane molecules to form one hydrate crystal and vice versa. This kinetic reaction is controlled by the multiphase fluid transport of the formation, and this embodiment can use darcy's law to characterize this multiphase flow system constructed from four components, gas-liquid-hydrate three-phase and methane-water-salt-hydrate, as follows:

This example considers the gas chimney-hydrate composite geological system as a multiphase transport process in porous sediments, comprising three phases (h-hydrate, l-liquid and a-gas) and four components (hydrate-h, water-w, methane-m and salt-s). First, the kinetic reaction of the hydrate (i.e., the transport model of the hydrate) r _h The gradient difference results of the fugacity under the local thermodynamic condition f (MPa) and the equilibrium condition feq (MPa), respectively, can be expressed as:

, Eq. (4)

Wherein ζ ₀ Is the kinetic coefficient of the hydrate reaction; ΔEa/R is 9752.73K; t _eq (K) is the equilibrium temperature and Tse is the reservoir temperature. Corresponding water r _w/>And methane r _m/>The following relationship is provided:

, Eq. (5)

. Eq. (6)

Assume that methane is immersed in pore gases and liquids, namely:

. Eq. (7)

Similar to the water component, there are:

. Eq. (8)

the current salinity X _l ^s is defined only by the initial liquid saturation S _l0 and the initial salinity X _l0 ^s:

. Eq. (9)

The reaction of natural gas hydrates can then be expressed as:

. Eq. (10)

wherein ρ _κ(kg/m³) (k=a, l, h) is the phase density; x _l ^m,X_l ^w and X _l ^s are mass fractions of methane, water and salt in pore water; ηi is the molar mass (i=m, w, h); then [ _κ (pa·s) (k=a, l) is the phase viscosity; g is gravity acceleration, 9.8N/kg; t (yr) represents time; d _l ^m and D _l ^s(m²/s) are the diffusion coefficients of methane and salts in the liquid; is the component flux (i=m, w).

The total thermal energy balance equation is expressed as:

, Eq. (11)

In the middle of And/> (K=r, h, l, a) are the heating value and thermal conductivity, respectively, of a particular phase. q _e is the local heat flow value (mW/m ²). The darcy's velocity u _κ (k=l, a) for a phase can be expressed as:

, Eq. (12)

. Eq. (13)

Finally, the latent heat of the natural gas hydrate in the reaction The method comprises the following steps:

. Eq. (14)

s114: the step of obtaining the reservoir sediment particle and water characteristic curve comprises the following steps:

；

Specifically, the present embodiment can normalize the relative content to measure reservoir sediment particle-water characteristic curves (SWCCs), namely:

, (15)

wherein S _e is the effective fluid saturation; s _l and S _g are liquid and gas saturation, respectively; s _li and S _gi are initial non-reducible liquid-gas saturation, and S _gi in this embodiment is 0.

The non-reducible liquid water S _li may be composed of clay content x _c andAnd (3) controlling:

, (16)

The relative permeabilities of gas phase k _rg and liquid phase k _rl as a function of saturation can be defined by the Corey model:

, (17)

, (18)

Wherein the pore size profile index pi is 7.3. As a pressure difference between the pore gas phase P _g (MPa) and the liquid phase P _l (MPa), the capillary pressure P _c (kPa) is defined by a pore breakthrough pressure P _th (kPa):

, (19)

Where ω is another Brookfield parameter. The effect of clay component x _c can be expressed as:

, (20)

, (21)

The clay content of the seafloor soil is 25-60%. When the porosity of the reservoir is set to be minimum 0.3 and maximum 0.7 respectively, the corresponding S _li range is 0.2781-0.3788.

S115: determining the reservoir permeability according to a permeability calculation;

the permeability is calculated as:

；

Wherein, Representing the reservoir permeability,/>Indicating the intrinsic permeability in the absence of natural gas hydrate in the reservoir,/>Representing the saturation of the natural gas hydrate.

In particular, the present embodiment may describe the formation intrinsic permeability k _h (mD) after the presence of hydrate in the reservoir as an exponential expression:

, (22)

Where k ₀ (mD) is the intrinsic permeability in the absence of hydrate. Based on the above description of the gas stack-bulk flow system, this embodiment sets two different permeability values to reflect the effects of bulk flow. In the interval of 0-180 mbsf, the permeability k ₀ is calculated to be 2 mD. Below the interval 180 mbsf, only in the gas stack, its value is set to 200 mD.

S116: the step of obtaining the reservoir tensile strength comprises:

the pore pressure relationship is:

S_v=P_c+P_l-T_sp-σ_h>0；

In particular, it is assumed in this example that tensile failure will only occur if the pore pressure is greater than the sum of the minimum principal stress and the tensile strength of the seabed formation. The final intra-pore pressure difference criterion term S _v (MPa) is:

S_v=P_c+P_l-T_sp-σ_h>0. (23)

The vertical stress σ _v (MPa) and the horizontal stress σ _h (MPa) can be related according to poisson's ratio in the stratum of the specific study area, and the expression is:

. (24)

The vertical stress sigma _v of the submarine sediment is simplified to be The overall density ρ _b of the deposit is 1910 kg/m ³. The reservoir tensile strength T _sp (MPa) was determined as:

, (25)

Wherein the Hoek-Brown constant m _i is 4, and the longitudinal wave velocity Vp (m/s) of the research area is inverted from the in-situ log curve as follows:

,(26)

S120: and carrying out numerical simulation on the natural gas hydrate by using the reservoir model after the reservoir parameters are configured.

Specifically, the embodiment can utilize a reservoir model after reservoir parameters are configured to conduct numerical simulation of various exploration and development conditions of the natural gas hydrate.

Further, S120 may include:

Next, various simulations in the present embodiment will be described in detail.

S121: natural gas hydrate dynamic formation process simulation.

Specifically, for a natural gas hydrate reservoir formation system, from the aspects of gas source, dynamic reaction, fluid migration path, hydrate stability domain change, block flow, sedimentary soil property and the like, a one-dimensional dynamic evolution model conforming to the prior geological background is established to demonstrate the reservoir formation process of the hydrate-containing sediments, and parameters used by the reservoir model can be referred to fig. 3, and specific analysis steps and corresponding expressions can be referred to the description in S116.

When the sea depth is greater than 500 meters, the sea floor temperature T _sf (°c) is related to the sea depth L:

. (27)

The deposit local temperature T _se (°c) is determined by the ground temperature gradients T _d (°c/m) and T _sf (°c), i.e.:

. (28)

S122: and simulating the natural gas hydrate formation evolution process.

In particular, to better reveal the evolution of this complex gas stack-block flow hydrate system, the present embodiment may choose 6 key control factors of formation pressure, temperature, capillary pressure, phase saturation, permeability and salinity that can provide sufficiently deep formation information. For the scenario corresponding to the parameters shown in fig. 3, both the initial gas and hydrate content were set to 0. Depending on the current sea level location of the investigation region, the present embodiment sets the old sea floor depth of 30kya BP to 1790 m. At this initial time, its hydrate stability domain floor was 147 mbsf. After the deposited particles had been packed, the pore water pressure in the packed deposit had increased slightly to 0.0101 MPa/m and the hydrostatic pressure was 0.01 MP/m.

Referring to fig. 4, it is an evolution state of (a) pressure difference change, (b) temperature difference change, (c) gas and hydrate content, (d) pore mineralization, (e) capillary pressure, and (f) permeability at 30, 20, 10, 5, 0 kr BP 5 times. Pressure change: pressure variation; temperature change: a temperature change; GH content: natural gas hydrate saturation; sanility: salinity; depth (mbsl): depth, below sea level; CAPILLARY PRESSURE: capillary pressure; permeability: permeability.

The embodiment can select 5 moments including 30, 20, 10, 5 kr BP 4 dividing times and current to display the current history state. In fig. 4a, if there is no sedimentation activity, the positive pressure change is set as the difference between the sedimentation pore pressure and the seawater hydrostatic pressure. Similarly, in fig. 4b, a positive temperature change is defined as the difference between the deposition temperature and the sea water temperature without deposition. Namely, the depth of the local seabed position gradually increases from 30 to 5 kyr BP and slightly decreases so far. The calculated hydrate is accumulated in a large quantity at the lower part of the hydrate channel, and the maximum saturation of the calculated hydrate can reach 47% by modeling (c of figure 4). It can be seen that the hydrate distribution and its saturation peak near the hydrate stability domain are all well matched with the drilling data. Simulation results show that free gas gradually accumulates at the top of the gas stack, which is the bottom of the natural gas hydrate channel and the bulk flow MTD3 channel. Current gas saturation levels are 20.3% and BSR may be formed. Depending on the formation environment of the gas stack, hydrates and free gas are difficult to coexist in the pores. The changes in salinity and capillary pressure are strongly positively correlated with the saturation of the hydrate, while the permeability is fully negatively correlated with the saturation of the hydrate (d, e, f of fig. 4). These phenomena are consistent with the general understanding of marine hydrate deposits. Overall, the combination of fluid reaction processes, formation characteristics and related key parameter values well explain how the gas stack and bulk flow determine the dynamic evolution and final production of the hydrate system.

S123: natural gas hydrate reservoir force imbalance simulation.

Referring to fig. 5, where (a) is the tensile strength and (b) is the evolution state of the intra-pore pressure difference criterion term S _v at 5 selected times. In fig. 5a, the abscissa THE TENSILE STRENGTH is tensile stress (Mpa) and the ordinate Depth (msl) is Depth (meters) below sea level. In fig. 5b, the abscissa DIFFERENT CHANGE ofS _v is the variation of the intra-pore pressure difference criterion term S _v, and the ordinate Depth (mbsl) is the Depth (meters) below sea level.

The sedimentary stress, the intensity distribution and the corresponding force balance of the geological system are important dynamic mechanisms of the development and evolution of the hydrate reservoir. Whether or not formation hydraulic fracturing occurs in clay-dominated fines layers and how pore overpressure propagates in coarse turbidity to create cracks are critical to understanding the presence and occurrence of hydrates. According to the stress and strength analyses in the above expressions (23) to (26), the present embodiment calculates the stress and strength values at these five times in a of fig. 5.

Simulation results show that: the local tensile strength gradually decreases from a maximum value at 30 kyr BP to a minimum value at 5 kyr BP; after that, it grows rapidly. The current tensile strength is substantially the same as that at time 10 kyr BP. Meanwhile, the result of the criterion item Sv of the intra-pore pressure difference shows that the tension fracture phenomenon occurs in the rest of the region except the bottom region of the study stratum of the beginning 30 kyr BP (b of fig. 5). The formation is most prone to fracture at 5 kyr BP and the presence of hydrates can greatly increase the likelihood of fracture behavior of the formation. Natural gas hydrate saturation varies significantly positively with Sv.

S124: different deposition scenarios simulate reservoir changes and hydrate distribution.

Referring to fig. 6, a is free gas, b is hydrate, c is the difference between values corresponding to the basic environment when the initial hydrate saturation is 5%, 10% and 15% respectively. GAS DIFFERENCE: a difference between the gas saturation and the corresponding base saturation; GH DIFFERENCE: a natural gas hydrate saturation to corresponding base saturation difference; depth (mbsl): depth, below sea level. SVDIFFERENCE the difference between the pressure difference criterion item Sv in the pore and the reference value. Fig. 7 is a diagram of six geological scenarios and their corresponding parameters in which natural gas hydrate may form in the investigation region.

Local gas supply, kinetic reaction and permeability are three decisive variables for simulating a natural gas hydrate system in a reservoir model. This example contemplates another 6 geological scenarios that may represent possible combinations of formation and fluid environments to verify different hydrate deposit occurrence conditions (fig. 7). This example shows the difference between the free gas, hydrate and intra-pore pressure difference criteria for these 6 scenarios and the results of the previous base conditions (fig. 6a, b).

Scenario 1 is a gas chimney and an upper formation with very high permeability. The results show that: the distribution range of the hydrate is basically consistent, but the saturation peak reaches 15%, the gas peak can reach 85%, and the distribution range is wider. Natural gas hydrates may coexist with free gas.

Scenario 2 shows that the gas supply is smaller and the reaction kinetics coefficient is smaller. Both the hydrate and free gas content were significantly reduced.

Scenario 3 has a large gas supply and a small reaction coefficient. The results show that the distribution range of the hydrate is wider. The highest position can reach about 95 mbsf, but the upward shift hydrate saturation peak can only reach 23%. The free gas content was unchanged but the peak position was elevated.

Scenario 4 has a larger supply of gas, the slowest reaction coefficient, and an increase in the upper deposit permeability. The results show that: although the hydrate and free gas are widely distributed, the content is very low.

Case 5 shows a higher gas supply and a slower kinetic reaction coefficient. The results show that although the hydrate distribution range is wide and the peak value is sufficiently high, the range of free gas content in the hydrate stability domain is also large and the peak value is 23%.

Scenario 6 has maximum gas supply, smaller reaction coefficient and larger stratum permeability in the gas chimney. The natural gas hydrate can fill the whole natural gas hydrate region, and scattered free gas exists in the pores.

By calculating these 6 intra-pore pressure difference criteria terms Sv, all positive values, indicate that fracturing will occur or occur (c of fig. 6). Meanwhile, the larger the hydrate content, the more easily hydraulic fracturing occurs.

S125: and simulating the geologic time hydrate formation evolution.

Referring to fig. 8, fig. 8 shows the differences between a) free gas, b) hydrate, c) intra-pore pressure difference criterion terms Sv and corresponding values in the basic environment at 3 initial hydrate saturations of 5%, 10% and 15%, respectively. SVDIFFERENCE: the difference between the intra-pore pressure difference criterion term Sv and the reference value.

In particular, it is also possible that: before 30kyr BP, a certain amount of hydrate is already present in the raw hydrate stability domain, with a larger shift in the hydrate stability domain, the lower half of hydrate decomposes and disappears, while the upper half of hydrate remains. This example sets the initial hydrate content to 5% (case 1), 10% (case 2) and 15% (case 3), and investigated the evolution process since 30kyr BP. Similarly, this example adopts the values corresponding to the differences of the hydrate, free gas and intra-pore pressure difference criterion terms Sv in the three cases and the basic cases. From the results, it can be seen that the free gas content also increases correspondingly (a of fig. 8). The peak of the hydrate in 3 cases reached 53%, 57% and 59%, respectively. The second hydrate peaks that may occur near 105 mbsf are 9%, 19% and 31%, respectively, almost coincident with the bottom of MTD2 in fig. 8 b. The intra-pore pressure difference criterion term curve remains positive, indicating that in this context the formation will develop a fracture (c of fig. 8). The higher the hydrate content, the stronger the breaking behaviour. Overall, 10% of the initial hydrate saturation is considered near perfect, more consistent with current well drilling and logging results for the presence of hydrate stability domains near MTD2 and MTD 3.

The embodiment of the application can solve the following technical problems:

1. comprehensively representing Liu Poou shallow surface engineering geological features, sea level historical change conditions and a deposition process from a numerical simulation angle, and constructing a proper one-dimensional dynamic reaction dynamics model of flow-force-thermal coupling geology-geophysics-dynamics;

2. the geological structure combination body such as the gas chimney, the gas-containing fluid flow pipeline and MTDs is arranged, and the formation evolution of a leakage type hydrate reservoir under the control of the combination body and the dynamic reservoir formation and distribution quantitative characterization technology of the natural gas hydrate are shown;

3. the method provides a mechanical instability judgment criterion for the influence of the hydrate content on the local stratum for the first time, and measures the evolution process and possibility of stratum fracture for the first time.

The beneficial effects are that:

firstly, the defect that the reservoir parameter factors are more to be controlled manually, such as sediment preparation, liquid supply, gas supply, hydrate formation reservoir temperature and pressure control and other modules, before simulation, is solved by adopting a physical simulation means to simulate reservoir formation change.

Secondly, the size and simulation scale limitation of a physical simulation device are broken through, and the influence of factors such as submarine sediment, sea level lifting and gas production characteristics on hydrate reservoir formation is considered under actual geological conditions to simulate the spatial distribution of the whole natural gas hydrate reservoir and the hydrate in a research area.

Thirdly, the leakage system can be dynamically and quantitatively analyzed from the long geological time to control the change of the hydrate reservoir and the dynamic reservoir evolution and the change of the spatial distribution of the hydrate.

Referring to fig. 9, the embodiment of the application further provides a device for simulating a reservoir of a leaky natural gas hydrate, which can implement the reservoir simulation method, and the device comprises:

It can be understood that the content in the above method embodiment is applicable to the embodiment of the present device, and the specific functions implemented by the embodiment of the present device are the same as those of the embodiment of the above method, and the achieved beneficial effects are the same as those of the embodiment of the above method.

The embodiment of the application also provides electronic equipment, which comprises a memory and a processor, wherein the memory stores a computer program, and the processor realizes the reservoir simulation method when executing the computer program. The electronic equipment can be any intelligent terminal including a tablet personal computer, a vehicle-mounted computer and the like.

It can be understood that the content in the above method embodiment is applicable to the embodiment of the present apparatus, and the specific functions implemented by the embodiment of the present apparatus are the same as those of the embodiment of the above method, and the achieved beneficial effects are the same as those of the embodiment of the above method.

Referring to fig. 10, fig. 10 illustrates a hardware structure of an electronic device according to another embodiment, the electronic device includes:

The processor 1001 may be implemented by using a general-purpose CPU (central processing unit), a microprocessor, an application-specific integrated circuit (ApplicationSpecificIntegratedCircuit, ASIC), or one or more integrated circuits, etc. to execute related programs to implement the technical solution provided by the embodiments of the present application;

Memory 1002 may be implemented in the form of read-only memory (ReadOnlyMemory, ROM), static storage, dynamic storage, or random access memory (RandomAccessMemory, RAM). Memory 1002 may store an operating system and other application programs, and when the technical solutions provided by the embodiments of the present disclosure are implemented in software or firmware, relevant program codes are stored in memory 1002 and invoked by processor 1001 to perform a reservoir simulation method of an embodiment of the present disclosure;

an input/output interface 1003 for implementing information input and output;

The communication interface 1004 is configured to implement communication interaction between the present device and other devices, and may implement communication in a wired manner (e.g. USB, network cable, etc.), or may implement communication in a wireless manner (e.g. mobile network, WIFI, bluetooth, etc.);

A bus 1005 for transferring information between the various components of the device (e.g., the processor 1001, memory 1002, input/output interface 1003, and communication interface 1004);

Wherein the processor 1001, the memory 1002, the input/output interface 1003, and the communication interface 1004 realize communication connection between each other inside the device through the bus 1005.

The embodiment of the application also provides a computer readable storage medium, which stores a computer program, and the computer program realizes the reservoir simulation method when being executed by a processor.

It can be understood that the content of the above method embodiment is applicable to the present storage medium embodiment, and the functions of the present storage medium embodiment are the same as those of the above method embodiment, and the achieved beneficial effects are the same as those of the above method embodiment.

The memory, as a non-transitory computer readable storage medium, may be used to store non-transitory software programs as well as non-transitory computer executable programs. In addition, the memory may include high-speed random access memory, and may also include non-transitory memory, such as at least one magnetic disk storage device, flash memory device, or other non-transitory solid state storage device. In some embodiments, the memory optionally includes memory remotely located relative to the processor, the remote memory being connectable to the processor through a network. Examples of such networks include, but are not limited to, the internet, intranets, local area networks, mobile communication networks, and combinations thereof.

The embodiments described in the embodiments of the present application are for more clearly describing the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided by the embodiments of the present application, and those skilled in the art can know that, with the evolution of technology and the appearance of new application scenarios, the technical solutions provided by the embodiments of the present application are equally applicable to similar technical problems.

It will be appreciated by persons skilled in the art that the embodiments of the application are not limited by the illustrations, and that more or fewer steps than those shown may be included, or certain steps may be combined, or different steps may be included.

The above described apparatus embodiments are merely illustrative, wherein the units illustrated as separate components may or may not be physically separate, i.e. may be located in one place, or may be distributed over a plurality of network elements. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

Those of ordinary skill in the art will appreciate that all or some of the steps of the methods, systems, functional modules/units in the devices disclosed above may be implemented as software, firmware, hardware, and suitable combinations thereof.

The terms "first," "second," "third," "fourth," and the like in the description of the application and in the above figures, if any, are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the application described herein may be implemented in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

It should be understood that in the present application, "at least one (item)" means one or more, and "a plurality" means two or more. "and/or" for describing the association relationship of the association object, the representation may have three relationships, for example, "a and/or B" may represent: only a, only B and both a and B are present, wherein a, B may be singular or plural. The character "/" generally indicates that the context-dependent object is an "or" relationship. "at least one of" or the like means any combination of these items, including any combination of single item(s) or plural items(s). For example, at least one (one) of a, b or c may represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", wherein a, b, c may be single or plural.

In the several embodiments provided by the present application, it should be understood that the disclosed apparatus and method may be implemented in other manners. For example, the above-described apparatus embodiments are merely illustrative, and for example, the above-described division of units is merely a logical function division, and there may be another division manner in actual implementation, for example, a plurality of units or components may be combined or may be integrated into another system, or some features may be omitted, or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.

The units described above as separate components may or may not be physically separate, and components shown as units may or may not be physical units, may be located in one place, or may be distributed over a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in the embodiments of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in software functional units.

The integrated units, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application may be embodied in essence or a part contributing to the prior art or all or part of the technical solution in the form of a software product stored in a storage medium, including multiple instructions to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method of the various embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a random access Memory (Random Access Memory RAM), a magnetic disk, or an optical disk, or other various media capable of storing a program.

The preferred embodiments of the present application have been described above with reference to the accompanying drawings, and are not thereby limiting the scope of the claims of the embodiments of the present application. Any modifications, equivalent substitutions and improvements made by those skilled in the art without departing from the scope and spirit of the embodiments of the present application shall fall within the scope of the claims of the embodiments of the present application.

Claims

1. A method of reservoir simulation of leaky natural gas hydrate, said method comprising:

performing numerical simulation on the natural gas hydrate by using the reservoir model after the reservoir parameters are configured;

The step of obtaining the reservoir porosity parameter comprises:

The expression of the initial porosity is:

；

the expression of the reservoir porosity parameter is:

；

Wherein, Representing the reservoir porosity parameter,/>Represents the saturation of natural gas hydrate;

the step of obtaining the natural gas hydrate gas-depth relationship model comprises the following steps:

The relation model is as follows:

；

Wherein, Indicating the methane gas concentration, z indicating the depth.

2. The method of reservoir simulation of a leaky natural gas hydrate as claimed in claim 1, wherein the step of obtaining a transport model and a reaction model of said natural gas hydrate includes:

The transportation model is as follows:

；

Wherein, Representing the transport model,/>Representing the kinetic coefficient of the hydrate reaction,/>Representing the temperature value,/>Represents equilibrium temperature,/>Representing reservoir temperature,/>Representing the reservoir porosity parameter,/>Representing the said local thermodynamic conditions of the plant,Representing the equilibrium condition;

Determining the reaction model as:

；

3. The method of reservoir simulation of a leaky natural gas hydrate as claimed in claim 1, wherein said step of obtaining said reservoir sediment particle and water characteristic curve includes:

；

4. The method of reservoir simulation of a leaky natural gas hydrate as claimed in claim 1, wherein said step of obtaining said reservoir permeability includes:

Determining the reservoir permeability according to a permeability calculation;

the permeability is calculated as:

；

The step of obtaining the reservoir tensile strength comprises:

the pore pressure relationship is:

S_v= P_c+P_l-T_sp-σ_h> 0；

5. A method of reservoir simulation of leaky natural gas hydrate as claimed in any one of claims 1 to 4, wherein said using said reservoir model after configuration of said reservoir parameters for numerical simulation of natural gas hydrate comprises:

6. A leaky natural gas hydrate reservoir simulation device, said device comprising:

the numerical simulation unit is used for performing numerical simulation on the natural gas hydrate by using the reservoir model after the reservoir parameters are configured;

The step of obtaining the reservoir porosity parameter comprises:

The expression of the initial porosity is:

；

the expression of the reservoir porosity parameter is:

；

The relation model is as follows:

；

Wherein, Indicating the methane gas concentration, z indicating the depth.

7. An electronic device comprising a memory storing a computer program and a processor implementing the method of any of claims 1 to 5 when the computer program is executed by the processor.

8. A computer readable storage medium storing a computer program, characterized in that the computer program, when executed by a processor, implements the method according to any one of claims 1 to 5.