CN112964613B

CN112964613B - Determination method, device and terminal for mass transfer parameters of shale reservoir

Info

Publication number: CN112964613B
Application number: CN202110148324.XA
Authority: CN
Inventors: 黄山; 马新华; 吴建发; 张鉴; 吴天鹏; 岳圣杰; 陈月; 邸云婷
Original assignee: Petrochina Co Ltd
Current assignee: Petrochina Co Ltd
Priority date: 2021-02-03
Filing date: 2021-02-03
Publication date: 2023-09-26
Anticipated expiration: 2041-02-03
Also published as: CN112964613A

Abstract

The application provides a method, a device and a terminal for determining mass transfer parameters of a shale reservoir, and belongs to the technical field of shale oil reservoir well test interpretation and digital simulation. The method comprises the following steps: determining a dimensionless pressure model based on the matrix pressure control model, the permeability stress sensitive functional relationship and the fractal effective permeability reduction functional relationship; determining a plurality of dimensionless matrix pressures based on the dimensionless pressure model; determining a first average pressure based on the plurality of dimensionless matrix pressures; determining a first mass transfer parameter based on a functional relationship of the first average pressure and the mass transfer parameter in response to the fracture pressure of the core being a fixed value; in response to the fracture pressure of the core being a variable, a second average pressure is determined based on a second functional relationship of the first average pressure and the matrix average pressure, and a second mass transfer parameter is determined based on the second average pressure and the functional relationship of the mass transfer parameter. The method improves the accuracy of mass transfer efficiency determined by mass transfer parameters.

Description

Determination method, device and terminal for mass transfer parameters of shale reservoir

Technical Field

The application relates to the technical field of shale oil reservoir well test interpretation and digital simulation, in particular to a method, a device and a terminal for determining mass transfer parameters of a shale oil reservoir.

Background

In a shale reservoir development system, as fluid in a fracture is gradually extracted, the fluid in a shale matrix gradually flows from the matrix to the fracture along a pressure gradient from high to low, and flows to a shaft through the fracture, and mass transfer efficiency between the matrix and the fracture in a shale reservoir plays a main role in the flow of the fluid in the shale, wherein the mass transfer efficiency is the mass of the fluid passing through a unit area per unit time on a matrix-fracture contact surface. Thus, accurately characterizing mass transfer efficiency between matrix-fractures in shale reservoirs is particularly important for determination of shale well production.

In the related art, mass transfer efficiency between a matrix and a crack is generally calculated by using a cross flow equation, and when the cross flow equation is used for calculation, a shape factor in the cross flow equation needs to be determined first, and then the shape factor is substituted into the cross flow equation to obtain the mass transfer efficiency; wherein the shape factor is a constant parameter set based on steady state characteristics of the mass transfer process between matrix-cracks.

In the related art, unstable state characteristics can also appear in the mass transfer process between the matrix and the cracks during the production of the oil well, and the shape factor is a constant parameter set based on the stable state characteristics, so that the determined channeling equation based on the shape factor set based on the stable state characteristics is inaccurate, and further, the determined mass transfer efficiency between the matrix and the cracks is inaccurate.

Disclosure of Invention

The embodiment of the application provides a method, a device and a terminal for determining mass transfer parameters of a shale reservoir, which can improve the mass transfer efficiency between a determined matrix and a crack. The technical scheme is as follows:

in one aspect, a method for determining mass transfer parameters of a shale reservoir is provided, the method comprising:

determining the thickness and constant coefficient of a fixed layer of a core based on experimental data of a saturated core centrifugal experiment of the core to be researched, and determining the maximum diameter, the fractal dimension and the tortuosity fractal dimension of a pore of the core based on experimental data of a mercury-pressing experiment of the core under preset pressure;

determining a dimensionless pressure model based on the matrix pressure control model, the permeability stress sensitive functional relationship and the fractal effective permeability reduction functional relationship;

determining a plurality of dimensionless matrix pressures based on the motionless layer thickness, the constant coefficient, the maximum diameter of the pores, the pore fractal dimension, the tortuosity fractal dimension, and the dimensionless pressure model;

determining a first average pressure based on the plurality of dimensionless matrix pressures;

determining a second functional relationship of matrix average pressure based on the first functional relationship of matrix average pressure of the core and the functional relationship of fracture pressure of the core;

Determining a first mass transfer parameter based on the first average pressure and a functional relationship of the mass transfer parameter in response to the fracture pressure of the core being a fixed value;

in response to fracture pressure of the core being a variable, a second average pressure is determined based on a second functional relationship of the first average pressure and the matrix average pressure, and a second mass transfer parameter is determined based on a functional relationship of the second average pressure and the mass transfer parameter.

In one possible implementation, the method further includes:

determining a three-dimensional dimensionless functional relationship of the mass transfer parameter based on the three-dimensional functional relationship of the mass transfer parameter and the dimensionless functional relationship of the mass transfer parameter;

determining a third mass transfer parameter based on the matrix first average pressure and a three-dimensional dimensionless functional relationship of the mass transfer parameter in response to the fracture pressure of the core being a fixed value;

and determining a fourth mass transfer parameter based on the matrix second average pressure and the three-dimensional dimensionless functional relationship of the mass transfer parameter in response to the fracture pressure of the core being a variable.

In one possible implementation, the determining the dimensionless pressure model based on the matrix pressure control model, the permeability stress sensitive functional relationship, and the fractal effective permeability reduction functional relationship includes:

Determining a control functional relationship of shale matrix pressure based on the matrix pressure control model, the functional relationship of permeability stress sensitivity and the functional relationship of fractal effective permeability reduction;

and performing dimensionless treatment on the control function relation of the shale matrix pressure to obtain the dimensionless pressure model.

In one possible implementation, the determining a control function of shale matrix pressure based on the matrix pressure control model, the permeability stress sensitive function, and the fractal effective permeability reduction function comprises:

determining a functional relationship of the matrix comprehensive permeability based on the functional relationship of the permeability stress sensitivity and the functional relationship of the fractal effective permeability reduction;

determining a control function relationship of the shale matrix pressure based on the function relationship of the matrix integrated permeability and the matrix pressure control model;

wherein, the permeability stress sensitivity functional relationship is:

the fractal effective permeability reduction functional relationship is as follows:

the functional relation of the matrix comprehensive permeability is as follows:

the matrix pressure control model is:

the control function relation of the shale matrix pressure is as follows:

wherein ,

wherein k is permeability; k (k) ₀ Absolute permeability; k (k) _m Is nonlinear permeability; c _t Is the comprehensive compression coefficient of the rock;is porosity; μ is the fluid viscosity; p (P) _m Is the matrix pressure; p (P) _i Is the matrix pressure at the initial conditions; p (P) _f Is fracture pressure; r is (r) _max Is the maximum diameter of the aperture; d (D) _f Fractal dimension for the aperture; d (D) _T Fractal dimension for said tortuosity; delta ₀ Thickness of the motionless layer; a, b is the constant coefficient; gamma ray _m Is the permeability modulus of the matrix; l (L) _c Is the distance between the crack and the center of the matrix; x is distance; t is time.

In one possible implementation manner, the dimensionless treatment on the control function relationship of the shale matrix pressure is performed to obtain a dimensionless pressure model, which includes:

acquiring a dimensionless first functional relationship;

based on the dimensionless first functional relationship, performing dimensionless treatment on the control functional relationship of the shale matrix pressure to obtain the dimensionless pressure model;

wherein, the control function relation of shale matrix pressure is:

the dimensionless first functional relationship is:

the dimensionless pressure model is:

wherein alpha and beta are nonlinear coefficients;

wherein ,

wherein ,k₀ Absolute permeability; c _t Is the comprehensive compression coefficient of the rock;is porosity; μ is the fluid viscosity; η is the pressure coefficient; p (P) _m Is the matrix pressure; p (P) _mD Is the dimensionless pressure of the substrate; p (P) _i Is the matrix pressure at the initial conditions; p (P) _f Is fracture pressure; r is (r) _max Is the maximum diameter of the aperture; d (D) _f Fractal dimension for the aperture; d (D) _T Fractal dimension for said tortuosity; delta ₀ Thickness of the motionless layer; a, b is the constant coefficient; b _D Is a dimensionless constant coefficient; gamma ray _m Is the permeability modulus of the matrix; gamma ray _mD A dimensionless permeability modulus that is the matrix; l (L) _c Is the distance between the crack and the center of the matrix; t is time; t is t _D Is dimensionless time; x is distance; x is x _D Is a dimensionless distance.

In one possible implementation, the determining a plurality of dimensionless matrix pressures based on the stationary layer thickness, the constant coefficient, a maximum diameter of the pores, the pore fractal dimension, the tortuosity fractal dimension, and the dimensionless pressure model includes:

determining a functional relationship of a dimensionless pressure based on the motionless layer thickness, the constant coefficient, the maximum diameter of the pore, the pore fractal dimension, the tortuosity fractal dimension, and the dimensionless pressure model;

Differentiating the functional relation of the dimensionless pressure to determine a nonlinear equation set of the dimensionless pressure;

a plurality of dimensionless matrix pressures is determined based on the system of non-linear equations of dimensionless pressures.

In one possible implementation, the determining a plurality of dimensionless matrix pressures based on the set of non-linear equations of dimensionless pressure includes:

converting the non-linear system of equations of dimensionless pressure into a matrix;

carrying out Newton iteration method solving on the matrix to obtain the plurality of dimensionless matrix pressures;

the representative equation of the non-linear equation set of the dimensionless pressure is:

wherein ,

wherein i=2, …, N-1, j=1, 2,3, …;

the matrix is:

wherein ,a_i ，b _i ，c _i ，d _i Coefficients are equation sets;is dimensionless matrix pressure; />Is a nonlinear coefficient; Δx _D Is a space step length; Δt (delta t) _D In time steps.

In one possible implementation, the determining the second functional relationship of matrix average pressure based on the first functional relationship of matrix average pressure of the core and the functional relationship of fracture pressure of the core includes:

acquiring a dimensionless second functional relationship;

performing dimensionless treatment on the functional relation of the fracture pressure based on the dimensionless second functional relation to obtain the functional relation of the dimensionless fracture pressure;

Based on the functional relation of the dimensionless fracture pressure and the first functional relation of the matrix average pressure, du Hamei integration is carried out on the functional relation of the matrix average pressure, so that a second functional relation of the matrix average pressure is obtained;

wherein the dimensionless second functional relationship is:

the fracture pressure has a functional relationship of:

P _f ＝P _∞ +(p _i -P _∞ )e ^-αt ；

functional relationship of the dimensionless fracture pressure:

the first functional relationship of the matrix average pressure is:

the second functional relationship of the matrix average pressure is:

where κ is a dimensionless decreasing coefficient, κ=l _c ² α/η；

wherein ,P_f Is fracture pressure; p (P) _fD Is dimensionless fracture pressure; p (P) _∞ The final stable fracture pressure; p (P) _mD Is the dimensionless pressure of the substrate;a first average pressure for the substrate; />A second average pressure for the substrate; gamma ray _m Is the permeability modulus of the matrix; gamma ray _mD A dimensionless permeability modulus that is the matrix; l (L) _c Is the distance between the crack and the center of the matrix; t is time; t is t _D Is dimensionless time; x is distance; x is x _D Is a dimensionless distance; p (P) _i Is the matrix pressure at the initial conditions; alpha is a decreasing coefficient; τ is a Du Hamei coefficient; η is the pressure coefficient.

In another aspect, a determination apparatus for mass transfer parameters of a shale reservoir is provided, the apparatus comprising:

The first determining module is used for determining the thickness and constant coefficient of the motionless layer of the core based on experimental data of a saturated core centrifugation experiment of the core to be researched, and determining the maximum diameter, the fractal dimension and the tortuosity fractal dimension of the pore of the core based on experimental data of a mercury-pressing experiment of the core under preset pressure;

the second determining module is used for determining a dimensionless pressure model based on the matrix pressure control model, the permeability stress sensitive functional relationship and the fractal effective permeability reduction functional relationship;

a third determination module for determining a plurality of dimensionless matrix pressures based on the immobilized layer thickness, the constant coefficient, a maximum diameter of the pores, the pore fractal dimension, the tortuosity fractal dimension, and the dimensionless pressure model;

a fourth determination module for determining a first average pressure based on the plurality of dimensionless matrix pressures;

a fifth determining module, configured to determine a second functional relationship of matrix average pressure based on the first functional relationship of matrix average pressure of the core and the functional relationship of fracture pressure of the core;

a sixth determining module, configured to determine a first mass transfer parameter based on a functional relationship between the first average pressure and the mass transfer parameter in response to the fracture pressure of the core being a fixed value;

And a seventh determining module, configured to determine a second average pressure based on a second functional relationship of the first average pressure and the matrix average pressure, and determine a second mass transfer parameter based on a functional relationship of the second average pressure and the mass transfer parameter in response to the fracture pressure of the core being a variable.

In one possible implementation, the apparatus further includes:

an eighth determination module configured to determine a three-dimensional dimensionless function relationship of the mass transfer parameter based on the three-dimensional function relationship of the mass transfer parameter and the dimensionless function relationship of the mass transfer parameter;

a ninth determining module, configured to determine a third mass transfer parameter based on the three-dimensional dimensionless functional relationship of the first matrix average pressure and the mass transfer parameter in response to the fracture pressure of the core being a fixed value;

and a tenth determination module, configured to determine a fourth mass transfer parameter based on the matrix second average pressure and the three-dimensional dimensionless functional relationship of the mass transfer parameters in response to the fracture pressure of the core being a variable.

In one possible implementation manner, the second determining module includes:

the first determining unit is used for determining a control functional relation of shale matrix pressure based on the matrix pressure control model, the functional relation of permeability stress sensitivity and the functional relation of fractal effective permeability reduction;

And the second determining unit is used for carrying out dimensionless treatment on the control function relation of the shale matrix pressure to obtain the dimensionless pressure model.

In one possible implementation manner, the first determining unit includes:

a first determining subunit, configured to determine a functional relationship of the matrix integrated permeability based on the functional relationship of the permeability stress sensitivity and the functional relationship of the fractal effective permeability reduction;

a second determining subunit, configured to determine a control function relationship of the shale matrix pressure based on the function relationship of the matrix integrated permeability and the matrix pressure control model;

wherein, the permeability stress sensitivity functional relationship is:

the functional relation of the matrix comprehensive permeability is as follows:

the matrix pressure control model is:

the control function relation of the shale matrix pressure is as follows:

wherein ,

In one possible implementation manner, the second determining unit includes:

an acquisition subunit, configured to acquire a dimensionless first functional relationship;

the processing subunit is used for carrying out dimensionless treatment on the control function relation of the shale matrix pressure based on the dimensionless first function relation to obtain the dimensionless pressure model;

wherein, the control function relation of shale matrix pressure is:

the dimensionless first functional relationship is:

the dimensionless pressure model is:

wherein alpha and beta are nonlinear coefficients;

wherein ,

In one possible implementation manner, the third determining module includes:

a third determining unit configured to determine a functional relationship of a dimensionless pressure based on the motionless layer thickness, the constant coefficient, a maximum diameter of the aperture, the aperture fractal dimension, the tortuosity fractal dimension, and the dimensionless pressure model;

the fourth determining unit is used for differentiating the functional relation of the dimensionless pressure and determining a nonlinear equation set of the dimensionless pressure;

a fifth determining unit for determining a plurality of dimensionless matrix pressures based on the set of non-linear equations of dimensionless pressures.

In one possible implementation manner, the fifth determining unit includes:

a conversion subunit, configured to convert the non-linear equation set of dimensionless pressures into a matrix;

A solving subunit, for carrying out Newton iteration method solving on the matrix to obtain the plurality of dimensionless matrix pressures;

wherein ,

wherein i=2, …, N-1, j=1, 2,3, …;

the matrix is:

In one possible implementation manner, the fifth determining module includes:

an acquisition unit for acquiring a dimensionless second functional relationship;

the processing unit is used for carrying out dimensionless treatment on the functional relation of the fracture pressure based on the dimensionless second functional relation to obtain the functional relation of the dimensionless fracture pressure;

a sixth determining unit, configured to obtain a second functional relationship of the matrix average pressure by integrating Du Hamei the functional relationship of the matrix average pressure based on the functional relationship of the dimensionless fracture pressure and the first functional relationship of the matrix average pressure;

wherein the dimensionless second functional relationship is:

the fracture pressure has a functional relationship of:

P _f ＝P _∞ +(p _i -P _∞ )e ^-αt ；

Functional relationship of the dimensionless fracture pressure:

the first functional relationship of the matrix average pressure is:

the second functional relationship of the matrix average pressure is:

where κ is a dimensionless decreasing coefficient, κ=l _c ² α/η；

wherein ,P_f Is fracture pressure; p (P) _f D is dimensionless fracture pressure; p (P) _∞ The final stable fracture pressure; p (P) _mD Is the dimensionless pressure of the substrate;a first average pressure for the substrate; />A second average pressure for the substrate; gamma ray _m Is the permeability modulus of the matrix; gamma ray _mD A dimensionless permeability modulus that is the matrix; l (L) _c Is the distance between the crack and the center of the matrix; t is time; t is t _D Is dimensionless time; x is distance; x is x _D Is a dimensionless distance; p (P) _i Is the matrix pressure at the initial conditions; alpha is a decreasing coefficient; τ is a Du Hamei coefficient; η is the pressure coefficient.

In another aspect, a terminal is provided that includes a processor and a memory having at least one program code stored therein, the at least one program code loaded and executed by the processor to perform the operations performed by the method for determining mass transfer parameters of a shale reservoir described above.

In another aspect, a computer readable storage medium having stored therein at least one program code loaded and executed by a processor to perform the operations performed by the method of determining mass transfer parameters of a shale reservoir described above is provided.

The technical scheme provided by the embodiment of the application has the beneficial effects that at least:

the embodiment of the application provides a method for determining mass transfer parameters of a shale reservoir, which can determine a plurality of dimensionless matrix pressures by using a dimensionless pressure model determined by the method, and further can determine a first average pressure when the fracture pressure is a fixed value by using the dimensionless matrix pressures, so that the first average pressure is substituted into a functional relation of the mass transfer parameters, and then the first mass transfer parameters when the fracture pressure is the fixed value can be determined; the method can also determine the second average pressure when the fracture pressure is a variable, and then the second average pressure is substituted into the functional relation of the mass transfer parameters, so that the second mass transfer parameters when the fracture pressure is a variable can be determined. Therefore, the mass transfer parameters determined by the method are changed along with the change of matrix pressure and the change of fracture pressure and are not constant parameters, so that the accuracy of the determined mass transfer parameters is improved, and the accuracy of the mass transfer efficiency determined by the mass transfer parameters is further improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for the description of the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a flow chart of a method for determining mass transfer parameters of a shale reservoir provided by an embodiment of the application;

FIG. 2 is a schematic illustration of a matrix-fracture fluid channeling model provided in an embodiment of the present application;

fig. 3 is a calculation flow chart of a newton iteration method provided by an embodiment of the present application;

FIG. 4 is a diagram of a dimensionless shape factor calculation result provided by an embodiment of the present application;

FIG. 5 is a block diagram of a shale reservoir mass transfer parameter determination apparatus in accordance with an embodiment of the present application;

fig. 6 is a block diagram of a terminal according to an embodiment of the present application.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the present application more apparent, the embodiments of the present application will be described in further detail with reference to the accompanying drawings.

The terms "first," "second," "third," and "fourth" and the like in the description and in the claims and drawings are used for distinguishing between different objects and not necessarily for describing a particular sequential or chronological order. Furthermore, the terms "comprising," "including," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, system, article, or terminal that comprises a list of steps or elements is not limited to the list of steps or elements but may, alternatively, include other steps or elements not expressly listed or inherent to such process, method, article, or terminal.

The embodiment of the application provides a method for determining mass transfer parameters of a shale reservoir, which is shown in fig. 1 and comprises the following steps:

step 101: the method comprises the steps that a terminal determines the thickness and constant coefficient of a fixed layer of a core based on experimental data of a saturated core centrifugal experiment of the core to be researched, and determines the maximum diameter, the fractal dimension and the tortuosity fractal dimension of a pore of the core based on experimental data of a mercury pressing experiment of the core under preset pressure.

Monitoring a saturated core centrifugal experiment through a nuclear magnetic resonance technology, and then fitting by using a model to obtain experimental data, wherein the experimental data comprises the thickness of an motionless layer of a core and a constant coefficient; the constant coefficients of the core are coefficients related to the solid surface and fluid properties.

The instrument adopted in the mercury-pressing experiment can be an AutoPoreIV9500 full-automatic mercury-pressing instrument, and the mercury-pressing instrument performs the mercury-pressing experiment by injecting mercury into the rock core, so that experimental data are obtained. The experimental data comprise capillary pressure injected into pores of the core and the percentage of mercury volume in a pore system under corresponding pressure, the capillary pressure curve of the core is determined by the terminal based on the experimental data of mercury injection experiments, and the maximum diameter, the pore fractal dimension and the tortuosity fractal dimension of the pores of the core are determined based on the capillary pressure curve.

Step 102: the terminal determines a dimensionless pressure model based on the matrix pressure control model, the permeability stress-sensitive functional relationship and the fractal effective permeability reduction functional relationship.

This step can be achieved by the following steps (1) - (2).

(1) The terminal determines a control function relationship of shale matrix pressure based on a matrix pressure control model, a function relationship of permeability stress sensitivity and a function relationship of fractal effective permeability reduction.

This step can be achieved by the following steps A1-A4.

A1: the terminal determines the functional relation of the matrix comprehensive permeability based on the functional relation of permeability stress sensitivity and the functional relation of fractal effective permeability reduction.

This step can be achieved by the following steps a11-a 12.

A11: the terminal determines a functional relationship for fractal effective permeability reduction based on the functional relationship of the fractal effective permeability and the functional relationship of the absolute permeability.

The functional relation of the fractal effective permeability and the functional relation of the absolute permeability can be directly obtained from the existing data.

The functional relation of the fractal effective permeability is used for expressing the functional relation among the thickness of the immobilized layer, the fractal dimension of the pore, the fractal dimension of tortuosity, the maximum diameter of the pore and the permeability. The functional relationship of absolute permeability is used to represent the functional relationship between the characteristic length of the porous medium, the fractal dimension of the pore, the fractal dimension of tortuosity, the maximum diameter of the pore and the absolute permeability.

Substituting the functional relation of the absolute permeability into the functional relation of the fractal effective permeability by the terminal to obtain a nonlinear functional relation of the permeability.

Wherein, the function relation of the fractal effective permeability is:

the absolute permeability is a function of:

the fractal effective permeability reduction has the following functional relationship:

wherein ,/>

where k is permeability, k ₀ For absolute permeability, P _m For matrix pressure, r _max Is the maximum diameter of the pore, D _f For the pore fractal dimension, D _T Fractal dimension, delta, for tortuosity ₀ For the thickness of the motionless layer, a and b are constant coefficients, L ₀ Is the characteristic length of the porous medium.

A12: and the terminal combines the functional relation of permeability stress sensitivity and the functional relation of fractal effective permeability reduction to determine the functional relation of the matrix comprehensive permeability.

The functional relation of permeability stress sensitivity can be directly obtained from the existing data, and the functional relation of permeability stress sensitivity is used for representing the functional relation between the permeability of the matrix and the matrix pressure.

Wherein, the permeability stress sensitivity functional relation is:

the functional relationship of the matrix comprehensive permeability is as follows:

wherein ,

where k is permeability, k ₀ For absolute permeability, k _m Is of non-linear permeability, P _m For matrix pressure, r _max Is the maximum diameter of the pore, D _f For the pore fractal dimension, D _T Fractal dimension, delta, for tortuosity ₀ For the thickness of the motionless layer, a and b are constant coefficients, gamma _m Is the permeability modulus of the matrix.

A2: the terminal determines a control function relationship of shale matrix pressure based on the function relationship of matrix integrated permeability and the matrix pressure control model.

The matrix pressure control model can be directly obtained from the existing data, and is used for representing the relation among matrix pressure, time, distance, rock comprehensive compression coefficient, porosity, fluid viscosity and nonlinear permeability.

Wherein, matrix pressure control model is:

wherein ,k_m Is nonlinear permeability, c _t Is the comprehensive compression coefficient of the rock,porosity, μ is fluid viscosity, P _m For matrix pressure, P _i For matrix pressure at initial conditions, P _f Is crack pressure, x is distance, t is time, L _c Is the distance between the crack and the center of the matrix.

Wherein, referring to fig. 2, the core comprises a matrix and cracks, and the crack spacing is H is assumed to be two parallel cracks on two sides of the matrix of the tight reservoir _m . The flow from the matrix to the fracture is one-dimensional and the direction of flow is perpendicular to the fracture surface.

Under initial conditions, the pressure within the matrix of the core was: p (P) _m | _t＝0 ＝P _i 。

From symmetry, there is no fluid in the middle of the matrix, i.e. the pressure gradient at the inner boundary is:

the outer boundaries of the two sides of the matrix are cracks, and then the pressure of the two sides is the crack pressure, namely the pressure of the outer boundaries is:

the terminal substitutes the functional relation of the matrix comprehensive permeability into a matrix pressure control model to obtain the control functional relation of the shale matrix pressure.

The control function relation of shale matrix pressure is as follows:

wherein ,

wherein ,k₀ For absolute permeability, c _t Is the comprehensive compression coefficient of the rock,porosity, μ is fluid viscosity, P _m For matrix pressure, P _i For the matrix pressure at initial conditions, r _max Is the maximum diameter of the pore, D _f For the pore fractal dimension, D _T Fractal dimension, delta, for tortuosity ₀ For the thickness of the motionless layer, a and b are constant coefficients, gamma _m Is the permeability modulus of the matrix.

(2) And carrying out dimensionless treatment on the control function relation of the shale matrix pressure by the terminal to obtain a dimensionless pressure control model.

This step can be achieved by the following steps A1-A4.

A1: the terminal obtains a dimensionless first functional relationship.

Wherein the dimensionless first functional relationship comprises a functional relationship of dimensionless pressure, a functional relationship of dimensionless time, a functional relationship of dimensionless distance, and a functional relationship of dimensionless permeability modulus and a functional relationship of dimensionless coefficient, see in particular table 1.

TABLE 1

A2: the terminal performs dimensionless treatment on the control function relation of the shale matrix pressure based on the dimensionless first function relation to obtain a dimensionless pressure model.

The terminal substitutes the dimensionless first functional relation into a control functional relation of shale matrix pressure to obtain a dimensionless pressure model.

The control function relation of shale matrix pressure is as follows:

the dimensionless first functional relationship is:

/>

the dimensionless pressure model is:

wherein, the dimensionless pressure in the matrix of the core is:

the dimensionless pressure gradient of the inner boundary is:

the dimensionless pressure of the outer boundary is:

wherein alpha and beta are nonlinear coefficients;

wherein ,

wherein ,k₀ For absolute permeability, c _t Is the comprehensive compression coefficient of the rock,porosity, μ is fluid viscosity, P _m For matrix pressure, P _mD For the dimensionless pressure of the matrix, P _i For matrix pressure at initial conditions, P _f Is the crack pressure, r _max Is the maximum diameter of the pore, D _f For the pore fractal dimension, D _T Fractal dimension, delta, for tortuosity ₀ For the thickness of the motionless layer, a and b are constant coefficients, b _D Is a dimensionless constant coefficient, θ _m Gamma, the permeability modulus of the matrix _mD Is the dimensionless permeability modulus, L, of the matrix _c Is the distance between the crack and the center of the matrix, t is the time, t _D Is dimensionless time, x is distance, x _D Is a dimensionless distance.

Step 103: the terminal determines a plurality of dimensionless matrix pressures based on the motionless layer thickness, the constant coefficient, the maximum diameter of the pores, the pore fractal dimension, the tortuosity fractal dimension, and the dimensionless pressure model.

This step can be achieved by the following steps (1) - (3).

(1) The terminal determines a functional relationship of the dimensionless pressure based on the motionless layer thickness, the constant coefficient, the maximum diameter of the pore, the pore fractal dimension, the tortuosity fractal dimension, and the dimensionless pressure model.

The terminal substitutes the thickness of the motionless layer, the constant coefficient, the maximum diameter of the pore, the fractal dimension of the pore and the fractal dimension of tortuosity into a dimensionless pressure model to obtain a functional relation of dimensionless pressure.

(2) And the terminal differentiates the functional relation of the dimensionless pressure and determines a nonlinear equation set of the dimensionless pressure.

The model is converted into a nonlinear equation set by finite difference because of strong nonlinearity of the function relation of dimensionless pressure.

wherein ,

where i=2, …, N-1, j=1, 2,3, ….

The initial conditional differential equation is:/>

where i=1, …, N-1, j=1.

The internal boundary condition difference equation is:

wherein ,

the outer boundary condition difference equation is:

wherein ,a_N ＝0，b _N ＝1，d _N ＝1，j＝1,2,3,…。

wherein ,a_i ，b _i ，c _i ，d _i Coefficients are equation sets;is dimensionless matrix pressure; />Is a nonlinear coefficient.

wherein ,Δx_D Dividing the distance from the center of the core to the crack into equal parts for the space step length, wherein the distance of each part is the space step length; Δt (delta t) _D The matrix pressure is determined periodically for a time step, i.e., a time interval for each determination of matrix pressure; the space step and the time step can be set according to the requirement.

(3) The terminal determines a plurality of dimensionless matrix pressures based on a system of nonlinear equations for dimensionless pressures.

This step can be achieved by the following steps A1-A4.

A1: the terminal converts the system of non-linear equations of dimensionless pressure into a matrix.

Wherein the matrix is:

a2: and solving the matrix by using a Newton iteration method by the terminal to obtain a plurality of dimensionless matrix pressures.

The terminal solves the matrix by adopting newton iteration, and the specific steps are shown in fig. 3. This step can be achieved by the following steps a21-a 27.

A21: setting a space step Deltax _D Time step Δt _D 。

A22: let alpha be ^j+1 ＝1，β ^j+1 ＝1。

A23: based on alpha ^j+1 ＝1，β ^j+1 Solving the matrix to obtain dimensionless matrix pressure at each point in the matrix

A24: dimensionless matrix pressure based on pointsObtaining pressure gradients at points in the matrix

A25: based on the pressure gradient, a new alpha is obtained ^j+1 。

A26: based on new alpha ^j+1 Solving the matrix to obtain new dimensionless matrix pressure of each point in the matrix/>

A27: repeating steps A23-A26 until newDimensionless matrix pressureDimensionless matrix pressure calculated last time +.>The difference in (2) meets the accuracy requirement, at which time a dimensionless matrix pressure at each point of a time step is obtained.

A28: calculating dimensionless matrix pressure for each point of next time stepRepeating the steps until the time is over.

The terminal can obtain the dimensionless matrix pressure P at any point in the matrix at any moment based on the method _mD (x _D ,t _D ) Obtaining a plurality of dimensionless matrix pressures.

Step 104: the terminal determines a first average pressure based on the plurality of dimensionless matrix pressures.

Wherein the terminal integrates the plurality of dimensionless matrix pressures to obtain a first average pressure.

Step 105: the terminal determines a second functional relationship of matrix average pressure based on the first functional relationship of matrix average pressure of the core and the functional relationship of fracture pressure of the core.

Wherein the first functional relationship of matrix average pressure is an integral of the plurality of matrix pressures. Wherein the functional relation of the fracture pressure is the functional relation of the fracture pressure changing along with time; in actual production, the fracture pressure is typically not constant, but varies over time, so it can be assumed that the fracture pressure index decreases.

Wherein, this step can be achieved by the following steps (1) - (3).

(1) The terminal obtains a dimensionless second functional relationship.

(2) And the terminal performs dimensionless treatment on the functional relation of the crack pressure based on the dimensionless second functional relation to obtain the functional relation of the dimensionless crack pressure.

Wherein the dimensionless second functional relationship is:

the fracture pressure is a function of:

P _f ＝P _∞ +(p _i -P _∞ )e ^-αt 。

functional relation of dimensionless fracture pressure:

the first functional relationship of matrix average pressure is:

wherein ,P_f For crack pressure, P _fD Is the dimensionless fracture pressure, P _∞ P for final stabilized fracture pressure _mD Is the dimensionless pressure of the substrate;gamma is the first average pressure _m For the permeability modulus of the matrix, L _c Is the distance between the crack and the center of the matrix, t is the time, t _D Is dimensionless time, x is distance; x is x _D For dimensionless distance, P _i For matrix pressure under initial conditions, gamma _mD Is the dimensionless permeability modulus of the matrix, alpha is the decreasing coefficient, eta ₀ For guiding pressure coefficient, P _i Is the matrix pressure at the initial conditions.

(3) Based on the functional relation of the dimensionless fracture pressure and the first functional relation of the matrix average pressure, du Hamei integral is carried out on the functional relation of the matrix average pressure, and a second functional relation of the matrix average pressure is obtained.

Wherein, the function relation of the dimensionless fracture pressure:

the first functional relationship of matrix average pressure is:

the second functional relationship of matrix average pressure is:

where κ is a dimensionless decreasing coefficient, κ=l _c ² α/η ₀ 。

wherein ,P_f For crack pressure, P _fD Is the dimensionless fracture pressure, P _∞ In order to achieve a final stable fracture pressure,for a first average pressure of the matrix +.>Gamma, the second average pressure of the matrix _m For the permeability modulus of the matrix, L _c Is the distance between the crack and the center of the matrix, t is the time, t _D Is dimensionless time, x is distance, x _D For dimensionless distance, P _i For matrix pressure under initial conditions, gamma _mD Is the dimensionless permeability modulus of the matrix, alpha is a decreasing coefficient, tau is a Du Hamei coefficient, eta ₀ Is the pressure guiding coefficient.

Step 106: and the terminal responds to the fracture pressure of the core as a fixed value, and determines a first mass transfer parameter based on the first average pressure and the functional relation of the mass transfer parameter.

This step can be achieved by the following steps (1) - (2).

(1) The terminal determines a dimensionless functional relationship of the mass transfer parameter based on the functional relationship of the cross-flow equation and the volume of the matrix fluid.

This step can be achieved by the following steps A1-A4.

A1: the terminal determines a functional relationship for the mass transfer parameter based on the functional relationship of the cross-flow equation and the volume of the matrix fluid.

The functional relationship between the crossflow equation and the volume of the matrix fluid can be directly obtained from shale reservoir data. The cross flow equation is used to represent the functional relationship between mass transfer parameters, matrix average pressure, fracture pressure and cross flow. From the point of view of mass balance, the fluid channeling between matrix and fracture is the volume of the fluid in the pores of the matrix rock mass that expands in volume due to the pressure drop, and thus the functional relationship between the volume of the matrix fluid is used to represent the functional relationship between volume, pressure and fluid channeling.

Wherein, the channeling equation is:

the volume of the matrix fluid is a function of:

the functional relationship of the mass transfer parameters is:

wherein eta is the pressure guide coefficient,

wherein ,q_mf Is the channeling amount, sigma is the shape factor, k _m For nonlinear permeability, V is the total volume of matrix rock mass, μ is fluid viscosity, For matrix mean pressure, +.>At a first average pressure, P _f For crack pressure, P _fD Is the stress of dimensionless cracks, which is->For matrix porosity, c _t Is the comprehensive compression coefficient of rock, t _D Is dimensionless time.

The mass transfer parameter comprises a shape factor, wherein the shape factor is the ratio of the cross-sectional area of fluid migration per unit volume to the characteristic flow distance, and is a parameter related to a plurality of geometric factors and is generally used for representing the mass transfer efficiency between the matrix and the crack in the multi-medium model. The shape factor is an important parameter in a crossflow equation, after the mass transfer factor is determined, the mass transfer efficiency between a matrix and a crack in the shale reservoir can be determined based on the crossflow equation, and further, a basis can be provided for shale oil reservoir well test interpretation, numerical simulation and yield decreasing analysis based on the mass transfer efficiency.

A2: and carrying out dimensionless treatment on the functional relation of the mass transfer parameters by the terminal to obtain the dimensionless functional relation of the mass transfer parameters.

The dimensionless functional relation of the mass transfer parameters is as follows:

wherein sigma is a mass transfer parameter,p, the dimensionless mean pressure of the matrix _fD Is the dimensionless fracture pressure, H _m Is the crack spacing, t _D Is dimensionless time.

wherein ,for the time bias of the dimensionless matrix pressure, deriving the dimensionless matrix pressure for each time based on the times and the dimensionless matrix pressures for the times, obtaining the time bias of the dimensionless matrix pressures.

A3: and substituting the first average pressure into the dimensionless function relation of the mass transfer parameters by the terminal to obtain the first mass transfer parameters.

The first mass transfer parameter is a one-dimensional dimensionless mass transfer parameter when the crack pressure is a fixed value, and is only suitable for the problem of one-dimensional unsteady state channeling.

Referring to fig. 4, the terminal can derive a first mass transfer parameter for each time based on a dimensionless functional relationship of the dimensionless matrix pressure to the partial conductance and mass transfer parameters for each time.

Step 107: the terminal responds to the fracture pressure of the core as a variable, determines a second average pressure based on a second functional relationship of the first average pressure and the matrix average pressure, and determines a second mass transfer parameter based on a functional relationship of the second average pressure and the mass transfer parameter.

The terminal substitutes the first average pressure into a second function relation of the matrix average pressure to obtain second average pressure; and substituting the second average pressure into a second functional relation of the mass transfer parameters by the terminal to obtain second mass transfer parameters.

The second mass transfer parameter is a one-dimensional dimensionless mass transfer parameter when the crack pressure is a variable, and is only suitable for the one-dimensional unsteady state channeling problem.

Step 108: the terminal determines the three-dimensional dimensionless function relationship of the mass transfer parameters based on the three-dimensional function relationship of the mass transfer parameters and the dimensionless function relationship of the mass transfer parameters.

Wherein, the three-dimensional functional relation of the mass transfer parameters is as follows:

σ _xyz ＝σ _x +σ _y +σ _z 。

the dimensionless functional relationship of the mass transfer parameters is:

the three-dimensional dimensionless functional relationship of the mass transfer parameters is:

/>

wherein ,σ_x ，σ _y ，σ _z Is a mass transfer parameter in the three-dimensional direction; h _mx ，H _my ，H _mz Is the crack spacing in the three-dimensional direction.

Wherein, when H _mx ＝H _my ＝H _mz When the mass transfer parameters are in a three-dimensional dimensionless functional relationship, the mass transfer parameters are as follows:

Step 109: and the terminal responds to the fracture pressure of the core as a fixed value, and determines a third mass transfer parameter based on the three-dimensional dimensionless functional relation of the first average pressure of the matrix and the mass transfer parameter.

And substituting the first average pressure of the matrix into the three-dimensional dimensionless function relation of the mass transfer parameters by the terminal to obtain a third mass transfer parameter.

The third mass transfer parameter is a three-dimensional dimensionless mass transfer parameter when the crack pressure is a fixed value, and is suitable for the problem of three-dimensional unsteady state channeling.

Step 110: and the terminal responds to the fracture pressure of the core as a variable, and determines a fourth mass transfer parameter based on the three-dimensional dimensionless functional relation of the second average pressure of the matrix and the mass transfer parameter.

And substituting the second average pressure of the matrix into the three-dimensional dimensionless function relation of the mass transfer parameters by the terminal to obtain a fourth mass transfer parameter.

The fourth mass transfer parameter is a three-dimensional dimensionless mass transfer parameter when the crack pressure is a variable, and is suitable for the problem of three-dimensional unsteady state channeling.

An embodiment of the present application provides a device for determining mass transfer parameters of a shale reservoir, referring to fig. 5, the device includes:

the first determining module 501 is configured to determine a thickness and a constant coefficient of a fixed layer of a core based on experimental data of a saturated core centrifugation experiment of the core to be studied, and determine a maximum diameter, a fractal dimension of the pore and a fractal dimension of tortuosity of the pore of the core based on experimental data of a mercury-pressing experiment of the core under a preset pressure;

a second determining module 502, configured to determine a dimensionless pressure model based on the matrix pressure control model, the permeability stress-sensitive functional relationship, and the fractal effective permeability reduction functional relationship;

a third determining module 503 for determining a plurality of dimensionless matrix pressures based on the motionless layer thickness, the constant coefficient, the maximum diameter of the pores, the pore fractal dimension, the tortuosity fractal dimension, and the dimensionless pressure model;

a fourth determination module 504 for determining a first average pressure based on the plurality of dimensionless matrix pressures;

a fifth determining module 505, configured to determine a second functional relationship of the matrix average pressure based on the first functional relationship of the matrix average pressure of the core and the functional relationship of the fracture pressure of the core;

A sixth determining module 506, configured to determine a first mass transfer parameter based on a functional relationship of the first average pressure and the mass transfer parameter in response to the fracture pressure of the core being a fixed value;

a seventh determining module 507 is configured to determine a second average pressure based on a second functional relationship of the first average pressure and the matrix average pressure in response to the fracture pressure of the core being a variable, and determine a second mass transfer parameter based on the second average pressure and the functional relationship of the mass transfer parameter.

In one possible implementation, the apparatus further includes:

an eighth determination module 508, configured to determine a three-dimensional dimensionless function relationship of the mass transfer parameter based on the three-dimensional function relationship of the mass transfer parameter and the dimensionless function relationship of the mass transfer parameter;

a ninth determining module 509, configured to determine, in response to the fracture pressure of the core being a fixed value, a third mass transfer parameter based on the matrix first average pressure and a three-dimensional dimensionless functional relationship of the mass transfer parameters;

a tenth determination module 510 is configured to determine a fourth mass transfer parameter based on the matrix second average pressure and the three-dimensional dimensionless functional relationship of the mass transfer parameter in response to the fracture pressure of the core being a variable.

In one possible implementation, the second determining module 502 includes:

and the second determining unit is used for carrying out dimensionless treatment on the control function relation of the shale matrix pressure to obtain a dimensionless pressure model.

In one possible implementation manner, the first determining unit includes:

the first determining subunit is used for determining the functional relation of the matrix comprehensive permeability based on the functional relation of permeability stress sensitivity and the functional relation of fractal effective permeability reduction;

the second determining subunit is used for determining the control function relation of the shale matrix pressure based on the function relation of the matrix comprehensive permeability and the matrix pressure control model;

wherein, the permeability stress sensitivity functional relation is:

the matrix pressure control model is:

the control function relationship of shale matrix pressure is as follows:

wherein ,/>

wherein k is permeability; k (k) ₀ Absolute permeability; k (k) _m Is nonlinear permeability; c _t Is the comprehensive compression coefficient of the rock; Is porosity; μ is the fluid viscosity; p (P) _m Is the matrix pressure; p (P) _i Is the matrix pressure at the initial conditions; p (P) _f Is fracture pressure; r is (r) _max Is the maximum diameter of the aperture; d (D) _f Fractal dimension for the pores; d (D) _T Fractal dimension for tortuosity; delta ₀ Is the thickness of the motionless layer; a, b are constant coefficients; gamma ray _m Is the permeability modulus of the matrix; l (L) _c Is the distance between the crack and the center of the matrix; x is distance; t is time.

In one possible implementation, the second determining unit includes:

the processing subunit is used for carrying out dimensionless treatment on the control function relation of the shale matrix pressure based on the dimensionless first function relation to obtain a dimensionless pressure model;

the control function relation of shale matrix pressure is as follows:

the dimensionless first functional relationship is:

the dimensionless pressure model is:

wherein alpha and beta are nonlinear coefficients;

wherein ,

wherein ,k₀ Absolute permeability; c _t Is the comprehensive compression coefficient of the rock;is porosity; μ is the fluid viscosity; η is the pressure coefficient; p (P) _m Is the matrix pressure; p (P) _mD Is the dimensionless pressure of the substrate; p (P) _i Is the matrix pressure at the initial conditions; p (P) _f Is fracture pressure; r is (r) _max Is the maximum diameter of the aperture; d (D) _f Fractal dimension for the pores; d (D) _T Fractal dimension for tortuosity; delta ₀ Is the thickness of the motionless layer; a, b are constant coefficients; b _D Is a dimensionless constant coefficient; gamma ray _m Is the permeability modulus of the matrix; gamma ray _mD A dimensionless permeability modulus that is the matrix; l (L) _c Is the distance between the crack and the center of the matrix; t is time; t is t _D Is dimensionless time; x is distance; x is x _D Is a dimensionless distance.

In one possible implementation, the third determining module 503 includes:

a third determining unit for determining a functional relationship of the dimensionless pressure based on the motionless layer thickness, the constant coefficient, the maximum diameter of the pore, the pore fractal dimension, the tortuosity fractal dimension, and the dimensionless pressure model;

a fifth determining unit for determining a plurality of dimensionless matrix pressures based on a non-linear system of equations of the dimensionless pressures.

In one possible implementation manner, the fifth determining unit includes:

a conversion subunit for converting the non-linear system of equations of dimensionless pressure into a matrix;

a solving subunit, which is used for solving the matrix by a Newton iteration method to obtain a plurality of dimensionless matrix pressures;

wherein ,

wherein i=2, …, N-1, j=1, 2,3, …;

the matrix is:

wherein ,a_i ，b _i ，c _i ，d _i Coefficients are equation sets;is dimensionless matrix pressure; />Is a nonlinear coefficient;Δx _D is a space step length; Δt (delta t) _D In time steps.

In one possible implementation, the fifth determining module 505 includes:

wherein the dimensionless second functional relationship is:

the fracture pressure is a function of:

P _f ＝P _∞ +(p _i -P _∞ )e ^-αt ；

functional relation of dimensionless fracture pressure:

the first functional relationship of matrix average pressure is:

the second functional relationship of matrix average pressure is:

wherein, kappa is the cause-freeSub-decreasing coefficient, k=l _c ² α/η；

The embodiment of the application provides a device for determining mass transfer parameters of a shale reservoir, which can determine a plurality of dimensionless matrix pressures by a dimensionless pressure model determined by the device, and further can determine a first average pressure when the fracture pressure is a fixed value by the dimensionless matrix pressures, so that the first average pressure is substituted into a functional relation of the mass transfer parameters, and then the first mass transfer parameters when the fracture pressure is the fixed value can be determined; the method can also determine the second average pressure when the fracture pressure is a variable, and then the second average pressure is substituted into the functional relation of the mass transfer parameters, so that the second mass transfer parameters when the fracture pressure is a variable can be determined. It can be seen that the mass transfer parameters determined by the apparatus are varied with variations in matrix pressure and variations in fracture pressure, and are not constant parameters, which results in improved accuracy of the determined mass transfer parameters and thus improved accuracy of mass transfer efficiency determined by the mass transfer parameters.

The embodiment of the application provides a terminal, which comprises a processor and a memory, wherein at least one program code is stored in the memory, and the at least one program code is loaded and executed by the processor to realize the instruction of the method for determining the mass transfer parameters of the shale reservoir in any implementation mode.

Fig. 6 shows a block diagram of a terminal 600 according to an exemplary embodiment of the present application. The terminal 600 may be a portable mobile terminal such as: a smart phone, a tablet computer, an MP3 player (Moving Picture Experts Group Audio Layer III, motion picture expert compression standard audio plane 3), an MP4 (Moving Picture Experts Group Audio Layer IV, motion picture expert compression standard audio plane 4) player, a notebook computer, or a desktop computer. Terminal 600 may also be referred to by other names of user terminals, portable terminals, laptop terminals, desktop terminals, etc.

In general, the terminal 600 includes: a processor 601 and a memory 602.

Processor 601 may include one or more processing cores, such as a 4-core processor, an 8-core processor, and the like. The processor 601 may be implemented in at least one hardware form of DSP (Digital Signal Processing ), FPGA (Field-Programmable Gate Array, field programmable gate array), PLA (Programmable Logic Array ). The processor 601 may also include a main processor, which is a processor for processing data in an awake state, also called a CPU (Central Processing Unit ), and a coprocessor; a coprocessor is a low-power processor for processing data in a standby state. In some embodiments, the processor 601 may be integrated with a GPU (Graphics Processing Unit, image processor) for taking care of rendering and rendering of content that the display screen is required to display. In some embodiments, the processor 601 may also include an AI (Artificial Intelligence ) processor for processing computing operations related to machine learning.

The memory 602 may include one or more computer-readable storage media, which may be non-transitory. The memory 602 may also include high-speed random access memory, as well as non-volatile memory, such as one or more disk storage terminals, flash memory storage terminals. In some embodiments, a non-transitory computer readable storage medium in memory 602 is used to store at least one instruction for execution by processor 601 to implement the method of determining mass transfer parameters of a shale reservoir provided by a method embodiment of the present application.

In some embodiments, the terminal 600 may further optionally include: a peripheral terminal interface 603, and at least one peripheral terminal. The processor 601, memory 602, and peripheral terminal interface 603 may be connected by a bus or signal lines. The respective peripheral terminals may be connected to the peripheral terminal interface 603 through a bus, signal line, or circuit board. Specifically, the peripheral terminal includes: at least one of radio frequency circuitry 604, a display 605, a camera assembly 606, audio circuitry 607, a positioning assembly 608, and a power supply 609.

The peripheral terminal interface 603 may be used to connect at least one peripheral terminal associated with an I/O (Input/Output) to the processor 601 and the memory 602. In some embodiments, the processor 601, memory 602, and peripheral terminal interface 603 are integrated on the same chip or circuit board; in some other embodiments, either or both of the processor 601, the memory 602, and the peripheral terminal interface 603 may be implemented on separate chips or circuit boards, which is not limited in this embodiment.

The Radio Frequency circuit 604 is configured to receive and transmit RF (Radio Frequency) signals, also known as electromagnetic signals. The radio frequency circuit 604 communicates with a communication network and other communication terminals via electromagnetic signals. The radio frequency circuit 604 converts an electrical signal into an electromagnetic signal for transmission, or converts a received electromagnetic signal into an electrical signal. Optionally, the radio frequency circuit 604 includes: antenna systems, RF transceivers, one or more amplifiers, tuners, oscillators, digital signal processors, codec chipsets, subscriber identity module cards, and so forth. The radio frequency circuit 604 may communicate with other terminals via at least one wireless communication protocol. The wireless communication protocol includes, but is not limited to: the world wide web, metropolitan area networks, intranets, generation mobile communication networks (2G, 3G, 4G, and 5G), wireless local area networks, and/or WiFi (Wireless Fidelity ) networks. In some embodiments, the radio frequency circuit 604 may also include NFC (Near Field Communication ) related circuits, which the present application is not limited to.

The display screen 605 is used to display a UI (User Interface). The UI may include graphics, text, icons, video, and any combination thereof. When the display 605 is a touch display, the display 605 also has the ability to collect touch signals at or above the surface of the display 605. The touch signal may be input as a control signal to the processor 601 for processing. At this point, the display 605 may also be used to provide virtual buttons and/or virtual keyboards, also referred to as soft buttons and/or soft keyboards. In some embodiments, the display 605 may be one, disposed on the front panel of the terminal 600; in other embodiments, the display 605 may be at least two, respectively disposed on different surfaces of the terminal 600 or in a folded design; in other embodiments, the display 605 may be a flexible display, disposed on a curved surface or a folded surface of the terminal 600. Even more, the display 605 may be arranged in a non-rectangular irregular pattern, i.e., a shaped screen. The display 605 may be made of LCD (Liquid Crystal Display ), OLED (Organic Light-Emitting Diode) or other materials.

The camera assembly 606 is used to capture images or video. Optionally, the camera assembly 606 includes a front camera and a rear camera. Typically, the front camera is disposed on the front panel of the terminal and the rear camera is disposed on the rear surface of the terminal. In some embodiments, the at least two rear cameras are any one of a main camera, a depth camera, a wide-angle camera and a tele camera, so as to realize that the main camera and the depth camera are fused to realize a background blurring function, and the main camera and the wide-angle camera are fused to realize a panoramic shooting and Virtual Reality (VR) shooting function or other fusion shooting functions. In some embodiments, camera assembly 606 may also include a flash. The flash lamp can be a single-color temperature flash lamp or a double-color temperature flash lamp. The dual-color temperature flash lamp refers to a combination of a warm light flash lamp and a cold light flash lamp, and can be used for light compensation under different color temperatures.

The audio circuit 607 may include a microphone and a speaker. The microphone is used for collecting sound waves of users and environments, converting the sound waves into electric signals, and inputting the electric signals to the processor 601 for processing, or inputting the electric signals to the radio frequency circuit 604 for voice communication. For the purpose of stereo acquisition or noise reduction, a plurality of microphones may be respectively disposed at different portions of the terminal 600. The microphone may also be an array microphone or an omni-directional pickup microphone. The speaker is used to convert electrical signals from the processor 601 or the radio frequency circuit 604 into sound waves. The speaker may be a conventional thin film speaker or a piezoelectric ceramic speaker. When the speaker is a piezoelectric ceramic speaker, not only the electric signal can be converted into a sound wave audible to humans, but also the electric signal can be converted into a sound wave inaudible to humans for ranging and other purposes. In some embodiments, the audio circuit 607 may also include a headphone jack.

The location component 608 is used to locate the current geographic location of the terminal 600 to enable navigation or LBS (Location Based Service, location based services). The positioning component 608 may be a positioning component based on the United states GPS (Global Positioning System ), the Beidou system of China, or the Galileo system of Russia.

A power supply 609 is used to power the various components in the terminal 600. The power source 609 may be alternating current, direct current, disposable battery or rechargeable battery. When the power source 609 includes a rechargeable battery, the rechargeable battery may be a wired rechargeable battery or a wireless rechargeable battery. The wired rechargeable battery is a battery charged through a wired line, and the wireless rechargeable battery is a battery charged through a wireless coil. The rechargeable battery may also be used to support fast charge technology.

In some embodiments, the terminal 600 further includes one or more sensors 610. The one or more sensors 610 include, but are not limited to: acceleration sensor 611, gyroscope sensor 612, pressure sensor 613, fingerprint sensor 614, optical sensor 615, and proximity sensor 616.

The acceleration sensor 611 can detect the magnitudes of accelerations on three coordinate axes of the coordinate system established with the terminal 600. For example, the acceleration sensor 611 may be used to detect components of gravitational acceleration in three coordinate axes. The processor 601 may control the display screen 605 to display the user interface in a landscape view or a portrait view according to the gravitational acceleration signal acquired by the acceleration sensor 611. The acceleration sensor 611 may also be used for the acquisition of motion data of a game or a user.

The gyro sensor 612 may detect a body direction and a rotation angle of the terminal 600, and the gyro sensor 612 may collect a 3D motion of the user on the terminal 600 in cooperation with the acceleration sensor 611. The processor 601 may implement the following functions based on the data collected by the gyro sensor 612: motion sensing (e.g., changing UI according to a tilting operation by a user), image stabilization at shooting, game control, and inertial navigation.

The pressure sensor 613 may be disposed at a side frame of the terminal 600 and/or at a lower layer of the display 605. When the pressure sensor 613 is disposed at a side frame of the terminal 600, a grip signal of the terminal 600 by a user may be detected, and a left-right hand recognition or a shortcut operation may be performed by the processor 601 according to the grip signal collected by the pressure sensor 613. When the pressure sensor 613 is disposed at the lower layer of the display screen 605, the processor 601 controls the operability control on the UI interface according to the pressure operation of the user on the display screen 605. The operability controls include at least one of a button control, a scroll bar control, an icon control, and a menu control.

The fingerprint sensor 614 is used for collecting the fingerprint of the user, and the processor 601 identifies the identity of the user according to the fingerprint collected by the fingerprint sensor 614, or the fingerprint sensor 614 identifies the identity of the user according to the collected fingerprint. Upon recognizing that the user's identity is a trusted identity, the processor 601 authorizes the user to perform relevant sensitive operations including unlocking the screen, viewing encrypted information, downloading software, paying for and changing settings, etc. The fingerprint sensor 614 may be disposed on the front, back, or side of the terminal 600. When a physical key or vendor Logo is provided on the terminal 600, the fingerprint sensor 614 may be integrated with the physical key or vendor Logo.

The optical sensor 615 is used to collect ambient light intensity. In one embodiment, processor 601 may control the display brightness of display 605 based on the intensity of ambient light collected by optical sensor 615. Specifically, when the intensity of the ambient light is high, the display brightness of the display screen 605 is turned up; when the ambient light intensity is low, the display brightness of the display screen 605 is turned down. In another embodiment, the processor 601 may also dynamically adjust the shooting parameters of the camera assembly 606 based on the ambient light intensity collected by the optical sensor 615.

A proximity sensor 616, also referred to as a distance sensor, is typically provided on the front panel of the terminal 600. The proximity sensor 616 is used to collect the distance between the user and the front of the terminal 600. In one embodiment, when the proximity sensor 616 detects a gradual decrease in the distance between the user and the front face of the terminal 600, the processor 601 controls the display 605 to switch from the bright screen state to the off screen state; when the proximity sensor 616 detects that the distance between the user and the front surface of the terminal 600 gradually increases, the processor 601 controls the display screen 605 to switch from the off-screen state to the on-screen state.

Those skilled in the art will appreciate that the structure shown in fig. 6 is not limiting of the terminal 600 and may include more or fewer components than shown, or may combine certain components, or may employ a different arrangement of components.

An embodiment of the present application provides a computer readable storage medium having stored therein at least one program code, the at least one program code loaded and executed by a processor to implement the steps in the method for determining mass transfer parameters of a shale reservoir of any of the above-described implementations.

It will be understood by those skilled in the art that all or part of the steps for implementing the above embodiments may be implemented by hardware, or may be implemented by program code related hardware, where the program may be stored in a computer readable storage medium, and the above storage medium may be a read only memory, a magnetic disk or an optical disk, etc.

The foregoing description of the preferred embodiments of the present application is not intended to limit the application, but rather, the application is to be construed as limited to the appended claims.

Claims

1. A method of determining mass transfer parameters of a shale reservoir, the method comprising:

acquiring a dimensionless second functional relationship;

based on the dimensionless second functional relation, performing dimensionless treatment on the functional relation of the fracture pressure to obtain the functional relation of the dimensionless fracture pressure;

wherein the dimensionless second functional relationship is:

the fracture pressure has a functional relationship of:

P _f ＝P _∞ +(p _i -P _∞ )e ^-αt ；

functional relationship of the dimensionless fracture pressure:

the first functional relationship of the matrix average pressure is:

the second functional relationship of the matrix average pressure is:

Where κ is a dimensionless decreasing coefficient, κ=l _c ² α/η；

wherein ,P_f Is fracture pressure; p (P) _fD Is dimensionless fracture pressure; p (P) _∞ The final stable fracture pressure; p (P) _mD Is the dimensionless pressure of the substrate;a first average pressure for the substrate; />A second average pressure for the substrate; gamma ray _m Is the permeability modulus of the matrix; gamma ray _mD A dimensionless permeability modulus that is the matrix; l (L) _c Is the distance between the crack and the center of the matrix; t is time; t is t _D Is dimensionless time; x is distance; x is x _D Is a dimensionless distance; p (P) _i Is the matrix pressure at the initial conditions; alpha is a decreasing coefficient; τ is a Du Hamei coefficient; η is the pressure coefficient;

determining a first mass transfer parameter based on a functional relation between the first average pressure and the mass transfer parameter in response to the fracture pressure of the core being a fixed value, wherein the mass transfer parameter comprises a shape factor, the shape factor is a ratio of the cross-sectional area of fluid migration per unit volume to a characteristic flow distance, and the first mass transfer parameter is a one-dimensional dimensionless mass transfer parameter when the fracture pressure is the fixed value;

and responding to the fracture pressure of the core as a variable, determining a second average pressure based on a second functional relation of the first average pressure and the matrix average pressure, and determining a second mass transfer parameter based on a functional relation of the second average pressure and the mass transfer parameter, wherein the second mass transfer parameter is a one-dimensional dimensionless mass transfer parameter when the fracture pressure is the variable.

2. The method of determining mass transfer parameters of a shale reservoir of claim 1, further comprising:

responding to the fracture pressure of the rock core as a fixed value, and determining a third mass transfer parameter based on the first average pressure and the three-dimensional dimensionless functional relation of the mass transfer parameter, wherein the third mass transfer parameter is the three-dimensional dimensionless mass transfer parameter when the fracture pressure is the fixed value;

and responding to the fracture pressure of the core as a variable, and determining a fourth mass transfer parameter based on the second average pressure and the three-dimensional dimensionless functional relation of the mass transfer parameter, wherein the fourth mass transfer parameter is the three-dimensional dimensionless mass transfer parameter when the fracture pressure is the variable.

3. The method of determining mass transfer parameters of a shale reservoir of claim 1, wherein said determining a dimensionless pressure model based on a matrix pressure control model, a permeability stress sensitive functional relationship, and a fractal effective permeability reduction functional relationship comprises:

4. The method of determining mass transfer parameters of a shale reservoir of claim 3, wherein said determining a control function of shale matrix pressure based on said matrix pressure control model, said permeability stress sensitive function and said fractal effective permeability reduction function comprises:

wherein, the permeability stress sensitivity functional relationship is:

the functional relation of the matrix comprehensive permeability is as follows:

The matrix pressure control model is:

P _m | _t＝0 ＝P _i ，/>

the control function relation of the shale matrix pressure is as follows:

wherein ,

5. The method of determining mass transfer parameters of a shale reservoir of claim 3, wherein said dimensionless processing of said control function relationship of shale matrix pressure to obtain a dimensionless pressure model comprises:

acquiring a dimensionless first functional relationship;

wherein, the control function relation of shale matrix pressure is:

The dimensionless first functional relationship is:

γ _mD ＝γ _m (P _i -P _f )，/>

the dimensionless pressure model is:

wherein alpha and beta are nonlinear coefficients;

wherein ,

6. The method of determining mass transfer parameters of a shale reservoir of claim 1, wherein said determining a plurality of dimensionless matrix pressures based on said stationary layer thickness, said constant coefficients, maximum diameter of said pores, said pore fractal dimension, said tortuosity fractal dimension, and said dimensionless pressure model comprises:

7. The method of determining mass transfer parameters of a shale reservoir of claim 6, wherein said determining a plurality of dimensionless matrix pressures based on a non-linear system of equations for the dimensionless pressures comprises:

wherein ,

the matrix is:

wherein i=2, …, N-1, j=1, 2,3, …;

8. A shale reservoir mass transfer parameter determination apparatus, the apparatus comprising:

wherein the dimensionless second functional relationship is:

γ _mD ＝γ _m (P _i -P _∞ )；

the fracture pressure has a functional relationship of:

P _f ＝P _∞ +(p _i -P _∞ )e ^-αt ；

functional relationship of the dimensionless fracture pressure:

the first functional relationship of the matrix average pressure is:

the second functional relationship of the matrix average pressure is:

where κ is a dimensionless decreasing coefficient, κ=l _c ² α/η；

a sixth determining module, configured to determine, in response to the fracture pressure of the core being a fixed value, a first mass transfer parameter based on a functional relationship between the first average pressure and the mass transfer parameter, where the mass transfer parameter includes a shape factor, the shape factor being a ratio of a cross-sectional area of fluid migration per unit volume to a characteristic flow distance, and being a parameter related to a plurality of geometric factors, and the first mass transfer parameter being a one-dimensional dimensionless mass transfer parameter when the fracture pressure is the fixed value;

And a seventh determining module, configured to determine, in response to the fracture pressure of the core being a variable, a second average pressure based on a second functional relationship between the first average pressure and the matrix average pressure, and determine, in response to the second average pressure and the functional relationship between the mass transfer parameter, a second mass transfer parameter, where the second mass transfer parameter is a one-dimensional dimensionless mass transfer parameter when the fracture pressure is a variable.

9. A terminal comprising a processor and a memory having stored therein at least one program code loaded and executed by the processor to implement the method of determining mass transfer parameters of a shale reservoir as claimed in any of claims 1-7.