CN116181324B - Method for evaluating equivalent permeability of reservoir after fracturing - Google Patents
Method for evaluating equivalent permeability of reservoir after fracturing Download PDFInfo
- Publication number
- CN116181324B CN116181324B CN202310229610.8A CN202310229610A CN116181324B CN 116181324 B CN116181324 B CN 116181324B CN 202310229610 A CN202310229610 A CN 202310229610A CN 116181324 B CN116181324 B CN 116181324B
- Authority
- CN
- China
- Prior art keywords
- reservoir
- crack
- model
- parameters
- permeability
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 230000035699 permeability Effects 0.000 title claims abstract description 65
- 238000000034 method Methods 0.000 title claims abstract description 51
- 239000011159 matrix material Substances 0.000 claims abstract description 16
- 239000011435 rock Substances 0.000 claims abstract description 16
- 238000010168 coupling process Methods 0.000 claims abstract description 15
- 238000003384 imaging method Methods 0.000 claims abstract description 15
- 230000008878 coupling Effects 0.000 claims abstract description 14
- 238000005859 coupling reaction Methods 0.000 claims abstract description 14
- 230000008859 change Effects 0.000 claims abstract description 10
- 238000011156 evaluation Methods 0.000 claims abstract description 9
- 239000012530 fluid Substances 0.000 claims description 13
- 238000004458 analytical method Methods 0.000 claims description 9
- 238000004364 calculation method Methods 0.000 claims description 9
- 230000008569 process Effects 0.000 claims description 7
- 208000035126 Facies Diseases 0.000 claims description 6
- 230000015572 biosynthetic process Effects 0.000 claims description 4
- 230000000877 morphologic effect Effects 0.000 claims description 4
- 238000010606 normalization Methods 0.000 claims description 4
- 239000007787 solid Substances 0.000 claims description 4
- 238000012937 correction Methods 0.000 claims description 3
- 238000013178 mathematical model Methods 0.000 claims description 2
- 230000000704 physical effect Effects 0.000 claims description 2
- 230000000452 restraining effect Effects 0.000 claims description 2
- 230000003068 static effect Effects 0.000 claims description 2
- 238000011158 quantitative evaluation Methods 0.000 abstract description 5
- 238000004422 calculation algorithm Methods 0.000 description 5
- 230000014509 gene expression Effects 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 238000006073 displacement reaction Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 238000004088 simulation Methods 0.000 description 2
- 230000006978 adaptation Effects 0.000 description 1
- 230000003044 adaptive effect Effects 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 230000005465 channeling Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 238000005325 percolation Methods 0.000 description 1
- 238000013139 quantization Methods 0.000 description 1
- 230000008521 reorganization Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B49/00—Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B47/00—Survey of boreholes or wells
- E21B47/002—Survey of boreholes or wells by visual inspection
- E21B47/0025—Survey of boreholes or wells by visual inspection generating an image of the borehole wall using down-hole measurements, e.g. acoustic or electric
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B2200/00—Special features related to earth drilling for obtaining oil, gas or water
- E21B2200/20—Computer models or simulations, e.g. for reservoirs under production, drill bits
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A10/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE at coastal zones; at river basins
- Y02A10/40—Controlling or monitoring, e.g. of flood or hurricane; Forecasting, e.g. risk assessment or mapping
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Geology (AREA)
- Mining & Mineral Resources (AREA)
- Physics & Mathematics (AREA)
- Environmental & Geological Engineering (AREA)
- Fluid Mechanics (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Geophysics (AREA)
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
- Testing Of Devices, Machine Parts, Or Other Structures Thereof (AREA)
Abstract
The invention relates to the technical field of reservoir permeability evaluation, in particular to a method for evaluating the equivalent permeability of a reservoir after fracturing, which comprises the steps of obtaining crack density, crack length, crack opening and crack inclination angle according to the characteristic crack parameters of core crack parameter data and imaging logging parameter data, and obtaining obtained parameters; obtaining physical parameters and geomechanical parameters according to logging, earthquake and rock core data, and establishing a reservoir model; establishing a crack density model based on the acquired parameters; performing grid division on the matrix and the cracks based on the crack density model and the reservoir model to establish a reservoir mechanics grid model; carrying out coupling solution under different physical quantities and multiple scales according to a reservoir model to obtain flow characteristics and pressure characteristics under different stress field conditions; based on the flow characteristics and the pressure characteristics, the reservoir permeability change characteristics are clear, a permeability evaluation result with high accuracy is obtained, and the problem that the accuracy of quantitative evaluation by the conventional logging interpretation permeability method is low is solved.
Description
Technical Field
The invention relates to the technical field of reservoir permeability evaluation, in particular to a method for evaluating equivalent permeability of a reservoir after fracturing.
Background
The permeability of the reservoir is a main factor for determining whether the reservoir can produce fluid or not, is used as an extremely important judgment index in the production of oil and gas wells, and has important guiding significance for the development of the oil and gas fields. At present, students at home and abroad do not form a uniform judging standard on the permeability change of the reservoir caused by fracture reformation forming cracks.
In the prior art, when the permeability of the reservoir is evaluated, quantitative evaluation is carried out by adopting a logging interpretation permeability method, but the method is embodied by a certain aspect of rock characteristics, the influence of crack morphology on the permeability of the reservoir is ignored, the method cannot represent the real permeability quantitative characteristics of the reservoir, and the accuracy of quantitative evaluation is reduced.
Disclosure of Invention
The invention aims to provide a method for evaluating equivalent permeability of a reservoir after fracturing, and aims to solve the problem that the accuracy of quantitative evaluation by the existing logging interpretation permeability method is low.
In order to achieve the above purpose, the invention provides a method for evaluating the equivalent permeability of a reservoir after fracturing, which comprises the following steps:
the method comprises the steps of representing fracture parameters according to core fracture parameter data and imaging logging parameter data to obtain fracture density, fracture length, fracture opening and fracture inclination, and obtaining obtained parameters;
obtaining physical parameters and geomechanical parameters according to logging, earthquake and rock core data, and establishing a reservoir model;
establishing a crack density model based on the acquired parameters;
performing grid division on the matrix and the fracture based on the fracture density model and the reservoir model to establish a reservoir mechanics grid model;
carrying out coupling solution under different physical quantities and multiple scales according to the reservoir model to obtain flow characteristics and pressure characteristics under different stress field conditions;
and determining the reservoir permeability change characteristic based on the flow characteristic and the pressure characteristic, and obtaining a permeability evaluation result.
The method for measuring and calculating the fracture density, the fracture length, the fracture opening and the fracture inclination angle according to the rock core fracture parameter data and the imaging logging parameter data, and obtaining measuring and calculating parameters comprises the following steps:
identifying cracks by utilizing core analysis according to the core crack parameter data, and calculating the crack opening and the crack density of the reservoir by counting the crack parameters in the rock sample under a microscope;
and identifying the crack by utilizing imaging logging according to the imaging logging parameter data, and extracting the crack length, the crack density, the crack opening and the crack inclination angle through imaging images to obtain the acquisition parameters.
Wherein the establishing a reservoir mechanics mesh model based on the fracture density model and the reservoir model meshing the matrix and the fracture comprises:
embedding the fracture density model and the reservoir model into a three-dimensional reservoir geological model to obtain a three-dimensional reservoir geological model with a fracture;
analyzing the influence of crack morphological parameter formation of the three-dimensional reservoir geological model with the crack to obtain analysis data;
establishing a geometric entity according to the node parameters of the three-dimensional reservoir geological model with the cracks;
and based on the geometric entity and the analysis data, utilizing a high-precision Grignard method and an f-f connection method to divide the matrix and the fracture grid to establish a reservoir mechanics grid model.
Wherein the physical parameters include porosity, permeability, and saturation.
Wherein the geomechanical parameters include Young's modulus, poisson's ratio, lithology and three-way ground stress.
The method for carrying out coupling solution under different physical quantities and multiple scales according to the reservoir model to obtain flow characteristics and pressure characteristics under different stress field conditions comprises the following steps:
and carrying out multi-physical field multi-scale coupling calculation according to the direct coupling of the reservoir model based on solid momentum conservation and fluid mass conservation to obtain flow characteristics and pressure characteristics under different stress field conditions.
According to the method for evaluating the equivalent permeability of the reservoir after fracturing, the fracture density, the fracture length, the fracture opening and the fracture dip angle are obtained by representing the fracture parameters according to the rock core fracture parameter data and the imaging logging parameter data, so that the obtained parameters are obtained; obtaining physical parameters and geomechanical parameters according to logging, earthquake and rock core data, and establishing a reservoir model; establishing a crack density model based on the acquired parameters; performing grid division on the matrix and the fracture based on the fracture density model and the reservoir model to establish a reservoir mechanics grid model; carrying out coupling solution under different physical quantities and multiple scales according to the reservoir model to obtain flow characteristics and pressure characteristics under different stress field conditions; and based on the flow characteristics and the pressure characteristics, the reservoir permeability change characteristics are clear, and a permeability evaluation result with high accuracy is obtained, so that the problem of low accuracy of quantitative evaluation by the conventional logging interpretation permeability method is solved.
Drawings
In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is an algorithm example graph of a method for evaluating equivalent permeability of a reservoir after fracturing, which is provided by the invention.
FIG. 2 is a schematic diagram of an initial equivalent permeability split for a reservoir.
Fig. 3 is a numerical simulation of a percolation field.
FIG. 4 is a plot of reservoir equivalent permeability versus production.
FIG. 5 is a plot of reservoir equivalent permeability versus single fracture parameter.
FIG. 6 is a plot of reservoir equivalent permeability versus dual fracture parameters.
Fig. 7 is a schematic diagram assuming a fluid flow direction.
Fig. 8 is a flow chart of a method for evaluating the equivalent permeability of a reservoir after fracturing provided by the invention.
Detailed Description
Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative and intended to explain the present invention and should not be construed as limiting the invention.
Referring to fig. 1 to 8, the invention provides a method for evaluating equivalent permeability of a reservoir after fracturing, which comprises the following steps:
s1, according to core fracture parameter data and imaging logging parameter data, characterizing fracture parameters to obtain fracture density, fracture length, fracture opening and fracture inclination, and obtaining obtained parameters;
specifically, analyzing and identifying cracks by utilizing a core according to the core crack parameter data, and calculating the crack opening and the crack density of the reservoir by counting the crack parameters in the rock sample under a microscope; and identifying the crack by utilizing imaging logging according to the imaging logging parameter data, and extracting the crack length, the crack density, the crack opening and the crack inclination angle through imaging images to obtain the acquisition parameters.
S2, a reservoir model is built according to physical parameters and geomechanical parameters obtained from logging, earthquake and rock core data;
in particular, the physical properties include porosity, permeability, and saturation. The geomechanical parameters include Young's modulus, poisson's ratio, lithology and three-way ground stress.
And obtaining physical parameters, lithology parameters, rock mechanical parameters, stress parameters and the like of the reservoir through logging, earthquake and rock core data, wherein the parameters at least comprise porosity, permeability, saturation, sedimentary facies, rock density, young modulus, poisson ratio, lithology, three-dimensional ground stress and the like, a reservoir geological model with the physical parameters and the geomechanical parameters is established through attribute coarsening and interpolation calculation methods, and the horizon information in the geological model is matched with the actual reservoir stratum.
And (3) performing dynamic and static fitting and correction on reservoir attribute data such as porosity, permeability, saturation, rock density and rock mechanical parameters by using logging data, restraining sedimentary facies and lithofacies and coarsening the sedimentary facies and lithofacies into a reservoir geological network model, and performing plane interpolation on the reservoir attribute data by using a kriging interpolation calculation method to generate a reservoir geological network attribute model, namely the reservoir model.
Specifically, by repeatedly applying the mesh adaptation library, an initial tetrahedral mesh is generated in each geological domain and constrained to generate the required degrees of freedom and the tetrahedral elements in each domain are assigned basic parameters associated with that domain. Wherein boundaries are specified as needed to control maximum and minimum element sizes and the desired degrees of freedom and local quantization between adjacent elements. These constraints are combined to generate a unified metric field specifying the preferred anisotropic mesh resolution, and new computational meshes are generated from existing meshes by sequentially applying local mesh reorganization meshes. Wherein the adaptive algorithm adjusts each candidate element in turn by: thinning by cutting and splitting, inserting a new vertex at the midpoint of the tetrahedral edge, and generating additional tetrahedral elements which will share the edge; coarsening by edge collapse, replacing tetrahedral edges with new vertexes positioned at midpoints, and removing zero-volume elements generated by the tetrahedral edges; surface/edge and edge/surface exchanges, introducing or deleting edge connections between vertices of element tuples forming convex shells; a single vertex is repositioned within the space spanned by elements having a common vertex.
S3, establishing a crack density model based on the acquired parameters;
specifically, the method based on numerical manifold and the geometric features of the crack divide the crack into three systems in different forms, and a crack model is established through a mathematical equation and a control equation. Wherein the fracture location is determined by both the poisson process and the fracture density model constraints. After the center position of the crack is randomly determined in the poisson process, determining the effectiveness of the point by a crack density model, carrying out extremely poor normalization on the crack density in a planarization mode, and obtaining the crack density model after normalization on the crack density; wherein the crack shape is reduced to a convex polygon to characterize a three-dimensional crack for facilitating subsequent analysis.
S4, based on the fracture density model and the reservoir model, carrying out grid division on the matrix and the fracture to establish a reservoir mechanics grid model;
embedding a crack characteristic model obtained from core-logging-seismic data into a three-dimensional reservoir geological model, forming a three-dimensional reservoir geological model with cracks in the reservoir model with the crack characteristic model, and analyzing the influence of crack morphological parameter formation; establishing a geometric entity according to the geological model node parameters; and performing grid division to establish a finite element reservoir mechanics grid model. And establishing an oil-gas two-phase seepage model according to the reservoir model, and setting production dynamic parameter boundary conditions. Specifically, embedding the fracture density model and the reservoir model into a three-dimensional reservoir geological model to obtain the three-dimensional reservoir geological model with the fracture; analyzing the influence of crack morphological parameter formation of the three-dimensional reservoir geological model with the crack to obtain analysis data; establishing a geometric entity according to the node parameters of the three-dimensional reservoir geological model with the cracks; and based on the geometric entity and the analysis data, utilizing a high-precision Grignard method and an f-f connection method to divide the matrix and the fracture grid to establish a reservoir mechanics grid model.
Based on a numerical manifold method, the cracks are divided into three types of continuous-limited thickness, discontinuous and intermittent interfaces and a micro-scale microprotrusion particle system according to the geometric characteristics of the cracks. However, the momentum and mass conservation are satisfied during the coupling process regardless of the dimensions of the crack:
wherein: sigma represents the total stress tensor; f represents a volume force; ρ represents the solid density; u represents a displacement vector; v represents a fluid velocity vector; alpha represents the Boit-Willis coefficient; epsilon v represents the volume strain; m represents a specific Austrian modulus; p represents the fluid pressure.
When the crack belongs to a continuous-limited thickness, the following relation is satisfied:
the flow in the fracture satisfies:
when the crack belongs to a discontinuous interface, the mechanical constraint type of different contact states on the crack section:
when opening, the device is: delta sigma's' f ＝k f ||u f || (6)
When closed: d=0 n u s ||＝0 (7)
Sliding time:
also the flow in the fracture satisfies equation (5).
When the crack belongs to a micro-scale microprotrusion particle system, the following relation is satisfied:
u＝∫εds+u cr +u r (10)
F＝F l +F contact (11)
the mechanical constraints of different contact states on the fracture segment satisfy the formulas (6) to (8), and the flow in the fracture satisfies the formula (5).
And embedding the established fracture model into a reservoir geometrical model, establishing an oil-gas two-phase seepage model according to the reservoir geometrical model, and setting production dynamic parameter boundary conditions. And performing relevant attribute assignment correction on the reservoir mechanical network model again by using the physical parameters.
The quasi-stress balance equation for the reservoir mechanical model can be expressed as:
wherein: σ' represents the effective stress based on the Biot theory; τ represents the shear stress.
For a transverse anisotropic material, the elastic stress-strain relationship and elastic stiffness matrix can be expressed as:
σ＝D·ε (13)
wherein: v (v) i Represents poisson's ratio in x, y, z directions; e (E) i The elastic modulus in the x, y, z directions is shown.
For a transverse anisotropic material, the elastic stiffness matrix can be expressed as:
G＝E/2(1+ν) (17)
convenient conditions for the reservoir geometry model include displacement boundary conditions and stress boundary conditions, so the hybrid boundary conditions are:
T＝T u +T f (18)
the reservoir heterogeneity constitutive equation expression is:
based on Navier-Stokes equation, substituting constitutive equation into balance equation to obtain displacement field equation expression:
the continuity equation expression taking into account the fluid dissipation function is:
wherein the fracture location is determined by both the poisson process and the fracture density model constraints. The method comprises the following specific steps:
performing extremely poor normalization on the crack density, and obtaining a crack density model by normalizing the crack density:
the poisson process obtains random numbers (x, y, z) from the research area, and after the poisson process randomly determines the center position of the crack, the effectiveness of the point is determined by a crack density model:
f(x,y,z)＝1/V (26)
wherein: v represents the volume of the study area.
By means of (x) i ，y i ，z i ，P i ) The interpolation algorithm calculates the probability density value P '(x, y, z) at the generated crack center position (x, y, z), if P' (x, y, z) > rand, the generated crack center position is valid, otherwise invalid, rand is the interval [0,1 ]]Random numbers on the same.
Dividing the crack grid, which comprises the following specific steps:
(1) calculating the intersection point of the crack surface and the matrix grid line; (2) calculating the intersection point condition of the grid lines and the plane where the cracks are located; (3) estimating the distribution condition of the crack grid; (4) calculating intersection lines among different fracture surfaces; (5) and determining the distribution condition of the final fracture grid. Wherein, the connection situation of four different grids is given.
In practice, because the flow equation between matrix grids is discrete by using a block-center finite volume method, the oil component channeling rate per unit area of each crack grid and the oil phase pressure in the center of the matrix grid are treated by adopting implicit green:
wherein:
dividing irregular quadrilateral crack grid into two triangular sub-grids omega 1 And omega 2 On the fracture surface, the area infinitesimal satisfies:
under the condition of a three-dimensional model, intersecting lines of a projection surface of the crack grid in the x direction, the y direction and the z direction and a plane where the crack grid is located are required to be calculated respectively, and then the geometric relationship between the intersecting points of the intersecting lines and the center of the crack grid is judged, so that the complexity of an algorithm is greatly increased, and the calculation efficiency is reduced. In view of this situation, this patent proposes a simple and practical algorithm, abbreviated as "path method", comprising the following specific steps:
assuming that there are ni crack grids (denoted as frmi, r=1, 2 … ni) in the matrix grid mi projected onto the Iij, the corresponding projected areas are denoted asThe corresponding projection planes are respectively +.> The matrix lattice mj has nj crack lattices (shown as frmj, r=1, 2 … ni) projected onto Iij, and the corresponding projection areas are shown as respectivelyThe corresponding projection planes are respectively +.>
Compared with the prior conventional method, the method adds an additional mi+1 grid connected between the crack frmi in mi and the crack frmj in mj, and adds the crack frmi and the crack frm j The area of intersection of the projected areas on the instep serves as the fluid flow area between the two fracture grids, again because the two fracture grids are each in the matrix grid m i And m j In, thus define f r mi -fr mj The geometry of the connection is:
wherein:
wherein: crack gridPermeability->
Wherein for newly added grid m n+1 It is thus demonstrated that since the conventional pEDFM method causes the crack edge, the flow barrier, to disappear, a small lattice is reconstructed from the normal vector direction n of the lattice at the crack fluid flow direction edge, assuming the fluid flow direction is m as shown in FIG. 6 1 →m 2 →m 3 Then set up the grid center at the edgeCoordinates are (x, y, z), and the normal vector component is expressed as (n) x ，n y ，n z ) Then newly generated grid m n+1 The center coordinates of the grid of cracks of (x+2/L+Δc, y, z), where Δc is a number that a computer can recognize that the difference is extremely small, for example, 0.0001.
S5, carrying out coupling solution under different physical quantities and multiple scales according to the reservoir model to obtain flow characteristics and pressure characteristics under different stress field conditions;
specifically, according to the reservoir model, based on direct coupling of solid momentum conservation and fluid mass conservation, multi-physical field multi-scale coupling calculation is performed, and flow characteristics and pressure characteristics under different stress field conditions are obtained.
The method for carrying out coupling solving under different physical quantity multi-scale according to the reservoir model comprises the following steps:
the seepage field and the stress field are mainly affected by the dynamic change of the porosity and the permeability, namely the effective stress is a tie connecting the seepage field and the stress field, and the effective stress principle in the porous medium can be expressed as follows:
wherein: sigma'. ij Representing the effective stress; delta ij Representing Kroneker symbols.
And obtaining a porosity dynamic model by using a volumetric strain concept:
the continuity equation is deduced according to the law of conservation of mass:
according to the built model, flow characteristics and pressure characteristics under different stress field conditions are obtained, the invention focuses on exploring and researching the change condition of reservoir permeability under the influence of fracture morphology, and the mathematical relation model between flow and pressure is built by adopting the following formula:
wherein: q represents flow; Δp represents pressure; r is R ou +R in Is the sum of the resistance of the inner and outer seepage areas.
Taking into consideration that an equivalent seepage flow method is adopted to obtain the equivalent permeability of the reservoir affected by the fracture morphology, simple assumption is made on the seepage flow condition of the reservoir, and the fracture half length L is used f As a boundary, dividing the near-well reservoir seepage area into an inner part and an outer part, dividing the outer seepage area into an I part, and regarding the seepage resistance as series connection; the internal seepage area is divided into two parts II and III, wherein II represents a fracture area, III represents an original reservoir area except for the fracture, and seepage resistance is regarded as parallel connection. I. Seepage resistance R of three parts II and III ou 、R inc 、R infi The expressions are respectively:
establishing a calculation formula of initial equivalent permeability of the reservoir with the fracture according to the influence of the fracture morphology on the initial permeability of the reservoir:
and S6, determining the reservoir permeability change characteristic based on the flow characteristic and the pressure characteristic, and obtaining a permeability evaluation result.
Specifically, according to a mathematical relation model between flow and pressure, a reservoir equivalent permeability change mathematical model is obtained:
wherein: k (k) * Representing the reservoir equivalent permeability; k. k (k) f Representing reservoir permeability and fracture permeability.
Reservoir equivalent permeability k * Quantitatively characterizing fluid flow capacity under the influence of fracture morphology, when the equivalent permeability k of a reservoir is * The larger the fluid flow is, the more fluid-tight.
Compared with the previous reservoir permeability evaluation method, the method has certain advantages. The invention takes into account fracture morphology and reservoir inhomogeneity and changes in stress field. And the reservoir permeability is evaluated by combining a test and numerical simulation, so that the reservoir permeability influenced by the fracture morphology is more accurate.
The foregoing disclosure is only illustrative of a preferred embodiment of a method for evaluating the permeability of a reservoir after fracturing, and it is not intended to limit the scope of the invention.
Claims (4)
1. The method for evaluating the equivalent permeability of the reservoir after fracturing is characterized by comprising the following steps of:
the method for obtaining the parameters comprises the steps of obtaining the crack density, the crack length, the crack opening and the crack inclination according to the core crack parameter data and the imaging logging parameter data to represent the crack parameters, and obtaining the obtained parameters, and comprises the following steps:
identifying cracks by utilizing core analysis according to the core crack parameter data, and calculating the crack opening and the crack density of the reservoir by counting the crack parameters in the rock sample under a microscope;
identifying cracks by using imaging logging according to the imaging logging parameter data, and extracting the crack length, the crack density, the crack opening and the crack inclination angle through imaging images to obtain acquisition parameters;
the method comprises the steps of obtaining physical parameters and geomechanical parameters according to logging, earthquake and core data, and establishing a reservoir model, wherein the physical parameters, the lithology parameters and the stress parameters of the reservoir are obtained through the logging, earthquake and core data, the parameters at least comprise porosity, permeability, saturation, sedimentary facies, rock density, young modulus, poisson's ratio, lithology and three-dimensional earth stress, the reservoir geological model with the physical parameters and the geomechanical parameters is established through attribute coarsening and interpolation calculation methods, and the layer position information of the reservoir geological model is matched with the actual reservoir layer position;
performing dynamic and static fitting and correction on reservoir attribute data by using logging data, restraining sedimentary facies and lithofacies and coarsening the sedimentary facies and the lithofacies into a reservoir geological network model, and performing plane interpolation on the reservoir attribute data by using a Kriging interpolation calculation method to generate the reservoir geological network attribute model, namely the reservoir model;
establishing a crack density model based on the acquired parameters, wherein the crack density model comprises a numerical manifold-based method and a system for dividing the crack into three different forms based on the geometric features of the crack, and establishing the crack model through a mathematical equation and a control equation, wherein the crack position is jointly determined by a poisson process and the crack density model constraint, the effectiveness of the crack center position is determined by the crack density model after the poisson process is randomly determined by the crack center position, the crack density is planarized, and the crack density is normalized to obtain the crack density model after normalization;
establishing a reservoir mechanics grid model by grid dividing a matrix and a fracture based on the fracture density model and the reservoir model, comprising:
embedding the fracture density model and the reservoir model into a three-dimensional reservoir geological model to obtain a three-dimensional reservoir geological model with a fracture;
analyzing the influence of crack morphological parameter formation of the three-dimensional reservoir geological model with the crack to obtain analysis data;
establishing a geometric entity according to the node parameters of the three-dimensional reservoir geological model with the cracks;
based on the geometric entity and the analysis data, utilizing a high-precision Grignard method and an f-f connection method to divide matrixes and crack grids to establish a reservoir mechanics grid model;
carrying out coupling solution under different physical quantities and multiple scales according to the reservoir model to obtain flow characteristics and pressure characteristics under different stress field conditions;
determining the reservoir permeability change characteristic based on the flow characteristic and the pressure characteristic to obtain a permeability evaluation result, wherein the permeability evaluation result comprises
Obtaining a reservoir equivalent permeability change mathematical model according to a mathematical relationship model between flow and pressure:
wherein: k (k) * Representing the reservoir equivalent permeability; k. k (k) f Representing reservoir permeability and fracture permeability.
2. The method for evaluating the equivalent permeability of a reservoir after fracturing according to claim 1,
the physical properties include porosity, permeability, and saturation.
3. The method for evaluating the equivalent permeability of a reservoir after fracturing according to claim 1,
the geomechanical parameters include Young's modulus, poisson's ratio, lithology and three-way ground stress.
4. The method for evaluating the equivalent permeability of a reservoir after fracturing according to claim 1,
carrying out coupling solution under different physical quantities and multiple scales according to the reservoir model to obtain flow characteristics and pressure characteristics under different stress field conditions, wherein the method comprises the following steps:
and carrying out multi-physical field multi-scale coupling calculation according to the direct coupling of the reservoir model based on solid momentum conservation and fluid mass conservation to obtain flow characteristics and pressure characteristics under different stress field conditions.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310229610.8A CN116181324B (en) | 2023-03-10 | 2023-03-10 | Method for evaluating equivalent permeability of reservoir after fracturing |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310229610.8A CN116181324B (en) | 2023-03-10 | 2023-03-10 | Method for evaluating equivalent permeability of reservoir after fracturing |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN116181324A CN116181324A (en) | 2023-05-30 |
| CN116181324B true CN116181324B (en) | 2024-02-23 |
Family
ID=86448726
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310229610.8A Active CN116181324B (en) | 2023-03-10 | 2023-03-10 | Method for evaluating equivalent permeability of reservoir after fracturing |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116181324B (en) |
Citations (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2918777A1 (en) * | 2007-07-09 | 2009-01-16 | Total Sa | METHOD, PROGRAM, AND COMPUTER SYSTEM FOR THE CONSILIATION OF HYDROCARBON RESERVOIR MODEL DATA. |
| CN104730596A (en) * | 2015-01-25 | 2015-06-24 | 中国石油大学(华东) | Discrete fracture modeling method based on multiscale factor restraint |
| CN206410979U (en) * | 2017-01-25 | 2017-08-15 | 重庆地质矿产研究院 | Core holder for simulating hydraulic fracturing and permeability test |
| CN107545113A (en) * | 2017-09-08 | 2018-01-05 | 西南石油大学 | The complicated seam net of untraditional reservoir hydraulic fracturing forms process analogy method |
| RU2661489C1 (en) * | 2017-09-06 | 2018-07-17 | Общество с ограниченной ответственностью "ЛУКОЙЛ-Инжиниринг" (ООО "ЛУКОЙЛ-Инжиниринг") | Method of integrating initial data to update filtration structure of non-uniform carbonate reservoirs |
| CN109490168A (en) * | 2018-11-30 | 2019-03-19 | 重庆科技学院 | Quantitative evaluation method of the shale gas reservoir difference mass transfer diffusion mechanism to Reservoir Seepage contribution ratio in capabilities |
| CN109887083A (en) * | 2019-01-29 | 2019-06-14 | 中国石油集团测井有限公司西南分公司 | A kind of method for building up of Fracture-Pore dual media coupling penetration rate model |
| CN110005389A (en) * | 2019-03-07 | 2019-07-12 | 西南石油大学 | A kind of ultra deep sandstone seam net transformation evaluation method based on heat flow piercement effect |
| CN110704888A (en) * | 2019-07-04 | 2020-01-17 | 成都理工大学 | Unconventional oil and gas reservoir encrypted well volume fracturing construction parameter optimization design method |
| WO2020056750A1 (en) * | 2018-09-21 | 2020-03-26 | 北京科技大学 | Method for identifying medium structure coupling and seam mesh morphology of shale gas reservoirs |
| CN112131737A (en) * | 2020-09-21 | 2020-12-25 | 中铁一局集团第二工程有限公司 | Permeability evaluation method for arch cover method construction considering blasting influence |
| WO2021108439A1 (en) * | 2019-11-26 | 2021-06-03 | Saudi Arabian Oil Company | Modeling reservoir permeability through estimating natural fracture distribution and properties |
| CN113435066A (en) * | 2021-08-26 | 2021-09-24 | 北京润泽创新科技有限公司 | Logging interpretation reservoir evaluation method based on digital core technology |
| CN114528729A (en) * | 2022-01-20 | 2022-05-24 | 中海石油(中国)有限公司海南分公司 | Method for predicting yield of buried hill fracture gas reservoir based on multi-scale coupling |
| WO2022226332A1 (en) * | 2021-04-22 | 2022-10-27 | Saudi Arabian Oil Company | Methods and systems for determining reservoir and fracture properties |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8731889B2 (en) * | 2010-03-05 | 2014-05-20 | Schlumberger Technology Corporation | Modeling hydraulic fracturing induced fracture networks as a dual porosity system |
| FR2967200A1 (en) * | 2010-11-10 | 2012-05-11 | IFP Energies Nouvelles | METHOD FOR CHARACTERIZING FRACTURE FRACTURE NETWORK AND METHOD FOR OPERATING IT |
| US9416630B2 (en) * | 2013-06-18 | 2016-08-16 | Baker Hughes Incorporated | Grid calculation for fluid flow modeling |
| US20200095858A1 (en) * | 2017-09-14 | 2020-03-26 | Saudi Arabian Oil Company | Modeling reservoir permeability through estimating natural fracture distribution and properties |
| CN110206522B (en) * | 2019-06-10 | 2019-12-20 | 西南石油大学 | Shale gas reservoir fracturing horizontal well fracturing fluid flowback simulation method |
-
2023
- 2023-03-10 CN CN202310229610.8A patent/CN116181324B/en active Active
Patent Citations (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2918777A1 (en) * | 2007-07-09 | 2009-01-16 | Total Sa | METHOD, PROGRAM, AND COMPUTER SYSTEM FOR THE CONSILIATION OF HYDROCARBON RESERVOIR MODEL DATA. |
| CN104730596A (en) * | 2015-01-25 | 2015-06-24 | 中国石油大学(华东) | Discrete fracture modeling method based on multiscale factor restraint |
| CN206410979U (en) * | 2017-01-25 | 2017-08-15 | 重庆地质矿产研究院 | Core holder for simulating hydraulic fracturing and permeability test |
| RU2661489C1 (en) * | 2017-09-06 | 2018-07-17 | Общество с ограниченной ответственностью "ЛУКОЙЛ-Инжиниринг" (ООО "ЛУКОЙЛ-Инжиниринг") | Method of integrating initial data to update filtration structure of non-uniform carbonate reservoirs |
| CN107545113A (en) * | 2017-09-08 | 2018-01-05 | 西南石油大学 | The complicated seam net of untraditional reservoir hydraulic fracturing forms process analogy method |
| WO2020056750A1 (en) * | 2018-09-21 | 2020-03-26 | 北京科技大学 | Method for identifying medium structure coupling and seam mesh morphology of shale gas reservoirs |
| CN109490168A (en) * | 2018-11-30 | 2019-03-19 | 重庆科技学院 | Quantitative evaluation method of the shale gas reservoir difference mass transfer diffusion mechanism to Reservoir Seepage contribution ratio in capabilities |
| CN109887083A (en) * | 2019-01-29 | 2019-06-14 | 中国石油集团测井有限公司西南分公司 | A kind of method for building up of Fracture-Pore dual media coupling penetration rate model |
| CN110005389A (en) * | 2019-03-07 | 2019-07-12 | 西南石油大学 | A kind of ultra deep sandstone seam net transformation evaluation method based on heat flow piercement effect |
| CN110704888A (en) * | 2019-07-04 | 2020-01-17 | 成都理工大学 | Unconventional oil and gas reservoir encrypted well volume fracturing construction parameter optimization design method |
| WO2021108439A1 (en) * | 2019-11-26 | 2021-06-03 | Saudi Arabian Oil Company | Modeling reservoir permeability through estimating natural fracture distribution and properties |
| CN112131737A (en) * | 2020-09-21 | 2020-12-25 | 中铁一局集团第二工程有限公司 | Permeability evaluation method for arch cover method construction considering blasting influence |
| WO2022226332A1 (en) * | 2021-04-22 | 2022-10-27 | Saudi Arabian Oil Company | Methods and systems for determining reservoir and fracture properties |
| CN113435066A (en) * | 2021-08-26 | 2021-09-24 | 北京润泽创新科技有限公司 | Logging interpretation reservoir evaluation method based on digital core technology |
| CN114528729A (en) * | 2022-01-20 | 2022-05-24 | 中海石油(中国)有限公司海南分公司 | Method for predicting yield of buried hill fracture gas reservoir based on multi-scale coupling |
Non-Patent Citations (4)
| Title |
|---|
| A multiscale neural network model for the prediction on the equivalent permeability of discrete fracture network;Chenhong Zhu;Journal of Petroleum Science and Engineering;1-15 * |
| An equivalent mathematical model for 2D stimulated reservoir volume simulation of hydraulic fracturing in unconventional reservoirs;Zhiqiang Li;ENERGY SOURCES, PART A: RECOVERY, UTILIZATION, AND ENVIRONMENTAL EFFECTS;第45卷(第3期);8946-8964 * |
| 变速率剪切滑移过程中页岩裂缝稳定性-渗透率演化规律;贾云中;陆朝晖;汤积仁;李大华;贺培;煤炭学报;46(009);2923-2931 * |
| 煤岩裂缝渗流能力实验评价及近井地层等效渗透率分析;张亮;魏虎超;王得志;王伟;杨红斌;郝永卯;战永平;任韶然;科学技术与工程;21(002);495-503 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN116181324A (en) | 2023-05-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Vasco et al. | Integrating dynamic data into high-resolution reservoir models using streamline-based analytic sensitivity coefficients | |
| US8275593B2 (en) | Reservoir modeling method | |
| US9922142B2 (en) | Systems and methods for subsurface reservoir simulation | |
| EP2601642B1 (en) | System and method for summarizing data on an unstructured grid | |
| EP3362640B1 (en) | History matching of hydrocarbon production from heterogenous reservoirs | |
| Wen et al. | Upscaling of channel systems in two dimensions using flow-based grids | |
| Durlofsky et al. | Uncertainty quantification for subsurface flow problems using coarse-scale models | |
| Zhang et al. | Solution of two key issues in arbitrary three-dimensional discrete fracture network flow models | |
| CN114283254B (en) | Core digital pore network model construction method based on nuclear magnetic resonance data | |
| EP3455654A1 (en) | Three-dimensional fracture abundance evaluation of subsurface formation based on geomechanical simulation of mechanical properties thereof | |
| CN109900617B (en) | Method for calculating permeability curve of fractured formation based on acoustoelectric imaging log | |
| CN107966732A (en) | The seismic properties change rate acquiring method being oriented to based on space structure | |
| Karimpouli et al. | A hierarchical sampling for capturing permeability trend in rock physics | |
| CN117852416A (en) | Multimode grouting precontrolled analysis method and system based on digital geological model | |
| McKoy et al. | Tight gas reservoir simulation: Modeling discrete irregular strata-bound fracture networks and network flow, including dynamic recharge from the matrix | |
| Meng et al. | An IFS-based fractal discrete fracture network for hydraulic fracture behavior of rock mass | |
| CN116181324B (en) | Method for evaluating equivalent permeability of reservoir after fracturing | |
| CN105844011A (en) | Capillary model-based permeability computing method | |
| Oliaei et al. | Some numerical issues using element‐free Galerkin mesh‐less method for coupled hydro‐mechanical problems | |
| He et al. | Numerical calculation of equivalent cell permeability tensors for general quadrilateral control volumes | |
| Oyerinde et al. | Experiences with streamline-based three-phase history matching | |
| CN109072692B (en) | Method for two-dimensional reservoir pressure estimation using integrated static bottom hole pressure survey data and simulation modeling | |
| Sahimi et al. | Upscaled unstructured computational grids for efficient simulation of flow in fractured porous media | |
| Liu et al. | Classification and evaluation for stimulated reservoir volume (SRV) estimation models using microseismic events based on three typical grid structures | |
| Li et al. | Generalized prism grid: a pillar-based unstructured grid for simulation of reservoirs with complicated geological geometries |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |