Pumping design method based on effective support coefficient

Abstract

The invention provides a pump injection design method based on an effective support coefficient, and belongs to the technical field of oil and gas field development, and the method comprises the following steps: S1, based on a fluid-solid coupling theory, establishing a hydraulic fracture proppant migration equivalent model considering a bedding fracture; s2, with the optimal laying area as the target, the hydraulic fracture proppant migration equivalent model is used for simulating the proppant migration conditions under different parameter combinations, and an effective support coefficient is calculated; s3, based on the calculation result of the effective support coefficient, analyzing the change rule of the effective support coefficient under different parameters, and establishing a distribution pattern; and S4, on the basis of the distribution pattern, the pump injection process is optimized by utilizing the optimal range of the effective support coefficient. By means of the method, optimization of pumping key parameters such as displacement, sand ratio, sand adding particle size and particle size combination can be achieved, improvement of the overall flow conductivity of a shale oil reservoir fracturing fracture system is achieved, and therefore the fracturing effect is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and gas field development, and in particular relates to a pump injection design method based on an effective support coefficient. Background Art

[0002] In recent years, the deterioration of oil and gas resource quality and the complexity of reservoir development have become new challenges facing oil and gas exploration and development. Shale oil and gas are unconventional oil and gas resources that are currently being vigorously developed. Exploring economically and effectively developing shale oil is of great practical significance. Shale oil reservoirs have poor reservoir properties, and conventional mining technology has unsatisfactory results. Horizontal well multi-stage volume fracturing technology is an effective means to develop shale oil, and the conductivity of shale fracturing fractures directly determines the development effect of shale oil. How to improve the conductivity of shale reservoir volume fracturing fractures, improve the fracturing effect, and increase the post-fracturing production capacity is a huge challenge facing the development of Jimusar shale oil reservoirs.

[0003] Shale oil has achieved a high yield with the help of large displacement + fine cutting + large sand volume fracturing technology, which has now been optimized to a combination of multi-cluster + temporary plugging + extreme flow limiting technology within the segment. Under such large-scale and large-displacement conditions, shale reservoirs with developed bedding face the problem of effective sand entry in complex fracture networks. In order to improve the overall conductivity of the shale oil reservoir fracturing fracture system and improve the fracturing effect, it is necessary to optimize the construction displacement, sand ratio, sand particle size and particle size combination and other pumping parameters. Therefore, it is urgent to invent a set of methods and diagrams for optimizing pumping design, clarify the influence of various pumping parameters on the effective paving of fractures, and lay the foundation for pumping optimization and improving fracturing effects.

[0004] Chinese invention patent CN111894545A discloses a method for determining a proppant pumping scheme, which includes: step 1, obtaining the primary reservoir type of the reservoir to be analyzed to be pumped with proppant, and determining the secondary reservoir type of the reservoir to be analyzed under the primary reservoir type according to the reservoir geological parameters of the reservoir to be analyzed, and simulating the fracture system morphology formed under different pumping conditions according to the secondary reservoir type; step 2, simulating the proppant migration and sedimentation law under different preset proppant pumping combination conditions according to the fracture system morphology, and determining the fracture system conductivity; step 3, according to the fracture system conductivity, screening the most potential fracture network structure and pumping scheme. This method can be used to evaluate the conductivity and fracturing well production capacity of fracture systems formed by different types of oil and gas reservoirs, different types of reservoirs, and oil and gas wells with different characteristics under different types of proppants and different pumping program combinations of fracturing fluids, which helps to improve the effective support fracture network volume and the conductivity of the entire fracture system. However, this method cannot comprehensively characterize the proppant laying range. Summary of the invention

[0005] In view of the problems existing in the above-mentioned prior art, the present invention provides a pumping design method based on the effective support coefficient. The technical problem to be solved by the present invention is how to optimize pumping parameters such as displacement, sand ratio, sand particle size and particle size combination, increase the paving area, and realize the improvement of the overall conductivity of the shale oil reservoir fracturing fracture system, thereby improving the fracturing effect.

[0006] In order to solve the above technical problems, the present invention provides a pump injection design method based on effective support coefficient, comprising the following steps:

[0007] Step S1: Based on the fluid-solid coupling theory, an equivalent model of proppant migration in hydraulic fractures considering bedding fractures is established;

[0008] Step S2: with the goal of optimizing the paving area, using the hydraulic fracture proppant migration equivalent model to simulate the proppant migration under different parameter combinations, and calculate the effective propping coefficient;

[0009] Step S3: Based on the calculation results of the effective support coefficient, analyze the variation law of the effective support coefficient under different parameters and establish a distribution chart;

[0010] Step S4: Based on the distribution map, the pumping process is optimized using the optimal range of the effective support coefficient.

[0011] Furthermore, in the step S1, the fluid-solid two-phase mass conservation equation of the fluid-solid coupling model of the proppant migration in the fracture is as follows:

[0012]

[0013]

[0014] Where α f is the liquid volume fraction; α s is the volume fraction of the particle phase; ρ f is the liquid density, kg / m 3 ρ s is the particle phase density, kg / m 3 ; is the liquid phase linear velocity, m / s; is the particle phase linear velocity, m / s.

[0015] Furthermore, the momentum conservation equation of the hydraulic fracture proppant migration equivalent model is as follows:

[0016]

[0017]

[0018] Where: ▽ is the vector differential operator; τ fis the liquid shear stress tensor, τ s is the solid phase shear stress tensor, kg / (m·s2); ρ f is the liquid density, ρ s is the solid phase density, kg / m 3 ; is the acceleration due to gravity, -9.81m / s 2 ; Momentum exchange coefficient between β particles, kg / (m 3 ·s); p represents the pressure exerted by the fluid on the solid, or the reaction force exerted by the solid on the fluid, Pa.

[0019] Furthermore, in step S1, the variable density discrete phase model and discrete element coupling method are used to describe the flow of fracturing fluid and proppant in the fracture, momentum conversion is used to track the flow trajectory of the particles, and Newton's momentum equation is used to describe each proppant particle in the flow field, and the force balance is achieved through the following equation:

[0020]

[0021]

[0022]

[0023] Where: F D is the particle drag coefficient per unit mass, s -1 ; is the particle collision force per unit mass related to the shear stress tensor, m / s 2 ; The unit is Basset force, m / s 2 ; is the lift, m / s 2 ;μ f is the fluid viscosity, Pa·s; d s is the particle diameter, mm; C D is the resistance coefficient, dimensionless; Re s is the Reynolds number.

[0024] Furthermore, in step S1, the interaction between proppant particles is calculated using dense molecular dynamics theory, and the expression is:

[0025]

[0026] In the formula, τ s is the particle phase shear stress tensor, kg / (m·s 2 ); γ is the particle energy dissipation rate, kg·m -1 ·s -3 Φ is the interphase energy transfer caused by the change of particle velocity, kg·m-1 ·s -3 .

[0027] Furthermore, in step S1, the Gidaspow drag force model is used to calculate the momentum exchange coefficient between the proppant particles, and the Johnson viscoelastic model is used to calculate the friction viscosity:

[0028]

[0029]

[0030] Where P friction is the friction viscosity coefficient, dimensionless; α s,min is the minimum particle phase volume fraction, dimensionless; α s,max is the maximum particle phase volume fraction and is dimensionless.

[0031] Furthermore, in step S1, according to the fluid flow rate during shale reservoir fracturing, the k-ε turbulence model is applied to process the fluid domain of the hydraulic fracture proppant migration equivalent model:

[0032] Turbulent kinetic energy equation:

[0033]

[0034] Dissipation rate equation:

[0035]

[0036] In the formula, Π k is the turbulent exchange term between turbulent kinetic energy, Π ε is the turbulent exchange term between dissipation rates, kg / (m·s 3 ), k is the turbulent kinetic energy, m 2 / s 2 ; σ k is the turbulent Prandtl number for the turbulent kinetic energy k, dimensionless; σ ε is the turbulent Prandtl number of the dissipation rate ε, dimensionless; G k,f is the turbulent kinetic energy, kg / (m·s 3 ); μ t is the fluid shear viscosity, Pa·s; ε is the dissipation rate, m 2 / s 3 ; C1, C2 are constants.

[0037] Furthermore, in step S1, the particle acceleration is affected by a force parallel to the particle movement direction, and the proppant flow is affected by gravity, drag force, particle collision force, virtual force and Basset force.

[0038] Furthermore, the calculation formula of the gravity is:

[0039]

[0040] In the formula, F g Gravity, m / s 2 .

[0041] Furthermore, the calculation formula of the drag force is:

[0042]

[0043] In the formula, F s is the drag force, m / s 2 ; C S A is the drag coefficient between the two phases, dimensionless; s is the particle surface area, mm 2 ; V S is the particle phase velocity, m / s.

[0044] Furthermore, the calculation formula of the particle collision force is:

[0045]

[0046] In the formula, F c is the particle collision force, m / s 2 .

[0047] Furthermore, the calculation formula of the virtual force is:

[0048]

[0049] In the formula, F vm is the virtual force, m / s 2 ;v f is the liquid phase velocity.

[0050] Furthermore, the calculation formula of the Basset force is:

[0051]

[0052] In the formula, F B is the Basset force, m / s 2 ; t is time, s; t′ is reference time, s.

[0053] Furthermore, in step S2, the calculation formula of the effective support coefficient C is as follows:

[0054] C=∫∫ΔS·α

[0055] Where, Δs: microelement area, m 2 ; α: proppant volume coefficient of the microelement.

[0056] Furthermore, in step S3, a distribution chart of effective support coefficient of vertical seams and a distribution chart of effective support coefficient of horizontal bedding fractures are established considering different sand amounts, displacements, particle sizes and particle size combinations.

[0057] The present invention provides a pumping design method based on an effective support coefficient. The distribution map obtained by the method can be used to accurately optimize the sand volume, displacement, particle size and particle size combination in the on-site construction pumping program, improve the non-balanced sand feeding between clusters, reasonably control the sand addition concentration, and ensure safe construction; the method can optimize pumping parameters such as displacement, sand ratio, sand addition particle size and particle size combination, and improve the overall conductivity of the shale oil reservoir fracturing fracture system, thereby improving the fracturing effect; the effective support coefficient is positively correlated with the effective paving area, and the pumping process is optimized within the optimal range of the effective support coefficient, which increases the effective paving area, thereby achieving an improvement in conductivity and a better fracturing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 The present invention is a flow chart of a pumping design method based on an effective support coefficient.

[0059] Figure 2 (a) is a schematic diagram of a large-scale hydraulic fracture morphology simulated by bedding influence in a pumping design method based on effective support coefficient of the present invention; Figure 2 (b) is a schematic diagram of an equivalent model of hydraulic fracture proppant migration in a pumping design method based on an effective support coefficient of the present invention.

[0060] Figure 3 (a) is a schematic diagram of the calculation results of the effective support factor under different liquid viscosity combinations with a particle size combination of 70 / 140:40 / 70:30 / 50 mesh = 1:3:6; Figure 3 (b) is a schematic diagram of the calculation results of the effective support factor under different liquid viscosity combinations with a particle size combination of 70 / 140:40 / 70:30 / 50 mesh = 1:2:7; Figure 3 (c) is a schematic diagram of the calculation results of the effective support coefficient under different liquid viscosity combinations with a particle size combination of 70 / 140:40 / 70:30 / 50 mesh = 1:6:3; Figure 3 (d) is a schematic diagram of the calculation results of the effective support coefficient under different liquid viscosity combinations with a particle size combination of 70 / 140:40 / 70:30 / 50 mesh = 1:9::0; Figure 3 (a), (b), (c) and (d) are all calculated and drawn under the condition of slick water viscosity of 5mPa.s and displacement of 5m3 / min. On this basis, 30 / 50 mesh is additionally carried by slick water of 10, 15, 20 and 50mPa.s, which is called mixed particle size liquid system; Figure 3The columnar figures in each cluster correspond to bedding fracture 1, bedding fracture 2, bedding fracture 3, bedding fracture 4, bedding fracture 5, bedding fracture 6 and vertical fracture from left to right.

[0061] Figure 4 It is a schematic diagram of calculation results of effective support coefficient of bedding fractures in a single particle size system according to a pumping design method based on effective support coefficient of the present invention; Figure 4 The columnar figures in each cluster correspond to bedding fracture 1, bedding fracture 2, bedding fracture 3, bedding fracture 4, bedding fracture 5 and bedding fracture 6 from left to right.

[0062] Figure 5 (a) is the distribution chart of effective support coefficient of vertical cracks under different liquid viscosities and particle sizes under mixed particle sizes; Figure 5 (b) is the distribution chart of effective support coefficient of bedding fractures under different liquid viscosities and particle sizes under mixed particle sizes.

[0063] Figure 6 (a) is the distribution chart of effective support coefficient of vertical cracks under different liquid viscosities and particle sizes under a single particle size; Figure 6 (b) is a distribution chart of effective support coefficient of bedding fractures under different liquid viscosities and particle sizes under a single particle size.

[0064] Figure 7 It is a schematic diagram of the results of the single-segment six-cluster recommended pumping parameters of a pumping design method based on the effective support coefficient of the present invention.

[0065] Figure 8 It is a calculation flow chart of a hydraulic fracture proppant migration equivalent model of proppant migration in a fracture of a pumping design method based on an effective support coefficient of the present invention; wherein, E / EM: Explicit / Explicit-Euler Method, explicit dual-Euler method; DDPM: Dense Discrete Phase Model, dense discrete phase model. DETAILED DESCRIPTION

[0066] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0067] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0068] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0069] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0070] In order to better understand the purpose, structure and function of the present invention, a pumping design method based on an effective support coefficient of the present invention is further described in detail below in conjunction with the accompanying drawings.

[0071] Embodiment 1:

[0072] like Figure 1 As shown, the present invention provides a pump injection design method based on an effective support coefficient, comprising the following steps:

[0073] Step S1: Based on the fluid-solid coupling theory, an equivalent model of proppant migration in hydraulic fractures considering bedding fractures is established;

[0074] Step S2: with the goal of optimizing the paving area, using the hydraulic fracture proppant migration equivalent model to simulate the proppant migration under different parameter combinations, and calculate the effective propping coefficient;

[0075] Step S3: Based on the calculation results of the effective support coefficient, analyze the variation law of the effective support coefficient under different parameters and establish a distribution chart;

[0076] Step S4: Based on the distribution map, the pumping process is optimized using the optimal range of the effective support coefficient.

[0077] Embodiment 2:

[0078] like Figure 1 As shown, the present invention provides a pump injection design method based on an effective support coefficient, comprising the following steps:

[0079] Step S1: Based on the fluid-solid coupling theory, an equivalent model of proppant migration in hydraulic fractures considering bedding fractures is established;

[0080] Step S2: with the goal of optimizing the paving area, using the hydraulic fracture proppant migration equivalent model to simulate the proppant migration under different parameter combinations, and calculate the effective propping coefficient;

[0081] Step S3: Based on the calculation results of the effective support coefficient, analyze the variation law of the effective support coefficient under different parameters and establish a distribution chart;

[0082] Step S4: Based on the distribution map, the pumping process is optimized using the optimal range of the effective support coefficient.

[0083] The difference between this embodiment and the first embodiment is that:

[0084] In the step S1, the fluid-solid two-phase mass conservation equation of the fluid-solid coupling model of the proppant migration in the fracture is as follows:

[0085]

[0086]

[0087] Where α f is the liquid volume fraction; α s is the volume fraction of the particle phase; ρ f is the liquid density, kg / m 3 ρ s is the particle phase density, kg / m 3 ; is the liquid phase linear velocity, m / s; is the particle phase linear velocity, m / s.

[0088] The momentum conservation equation of the hydraulic fracture proppant migration equivalent model is as follows:

[0089]

[0090]

[0091] Where: ▽ is the vector differential operator; τ f is the liquid shear stress tensor, τ s is the solid phase shear stress tensor, kg / (m·s 2 );ρ f is the liquid density, ρ s is the solid phase density, kg / m 3 ; is the acceleration due to gravity, -9.81m / s 2 ; Momentum exchange coefficient between β particles, kg / (m 3·s); p represents the pressure exerted by the fluid on the solid or the reaction force exerted by the solid on the fluid, Pa.

[0092] In step S1, the variable density discrete phase model and discrete element coupling method are used to describe the flow of fracturing fluid and proppant in the fracture, momentum conversion is used to track the flow trajectory of particles, and Newton's momentum equation is used to describe each proppant particle in the flow field, and the force balance is achieved through the following equation:

[0093]

[0094]

[0095]

[0096] Where: F D is the particle drag coefficient per unit mass, s -1 ; is the particle collision force per unit mass related to the shear stress tensor, m / s 2 ; The unit is Basset force, m / s 2 ; is the lift, m / s 2 ;μ f is the fluid viscosity, Pa·s; d s is the particle diameter, mm; C D is the resistance coefficient, dimensionless; Re s is the Reynolds number.

[0097] In step S1, the interaction between proppant particles is calculated using dense molecular dynamics theory, and the expression is:

[0098]

[0099] In the formula, τ s is the particle phase shear stress tensor, kg / m·s 2 ; γ is the particle energy dissipation rate, kg·m -1 ·s -3 Φ is the interphase energy transfer caused by the change of particle velocity, kg·m -1 ·s -3 .

[0100] In step S1, the Gidaspow drag force model is used to calculate the momentum exchange coefficient between the proppant particles, and the Johnson viscoelastic model is used to calculate the friction viscosity:

[0101]

[0102]

[0103] Where P friction is the friction viscosity coefficient, dimensionless; α s,min is the minimum particle phase volume fraction, dimensionless; α s,max is the maximum particle phase volume fraction and is dimensionless.

[0104] In step S1, according to the fluid flow rate during shale reservoir fracturing, the k-ε turbulence model is applied to process the fluid domain of the hydraulic fracture proppant migration equivalent model:

[0105] Turbulent kinetic energy equation:

[0106]

[0107] Dissipation rate equation:

[0108]

[0109] In the formula, Π k is the turbulent exchange term between turbulent kinetic energy, Π ε is the turbulent exchange term between dissipation rates, kg / (m·s 3 ), k is the turbulent kinetic energy, m 2 / s 2 ; σ k is the turbulent Prandtl number for the turbulent kinetic energy k, dimensionless; σ ε is the turbulent Prandtl number of the dissipation rate ε, dimensionless; G k,f is the turbulent kinetic energy, kg / (m·s 3 ); μ t is the fluid shear viscosity, Pa·s; ε is the dissipation rate, m 2 / s 3 ; C1, C2 are constants.

[0110] In the step S1, the particle acceleration is affected by a force parallel to the particle movement direction, and the proppant flow is affected by gravity, drag force, particle collision force, virtual force and Basset force.

[0111] The calculation formula of gravity is:

[0112]

[0113] In the formula, F g Gravity, m / s 2 .

[0114] The calculation formula of the drag force is:

[0115]

[0116] In the formula, Fs is the drag force, m / s 2 ; C S A is the drag force coefficient between the two phases, dimensionless; s is the particle surface area, mm 2 ; V S is the particle phase velocity, m / s.

[0117] The calculation formula of the particle collision force is:

[0118]

[0119] In the formula, F c is the particle collision force, m / s 2 The pumping design method based on effective support coefficient according to claim 8 is characterized in that the calculation formula of the virtual force is:

[0120]

[0121] In the formula, F vm is the virtual force, m / s 2 ;v f is the liquid phase velocity.

[0122] Characterized in that the Basset force:

[0123]

[0124] In the formula, F B is the Basset force, m / s 2 ; t is time, s; t′ is reference time, s.

[0125] Embodiment 3:

[0126] like Figure 1 As shown, the present invention provides a pump injection design method based on an effective support coefficient, comprising the following steps:

[0127] Step S1: Based on the fluid-solid coupling theory, an equivalent model of proppant migration in hydraulic fractures considering bedding fractures is established;

[0128] Step S2: with the goal of optimizing the paving area, using the hydraulic fracture proppant migration equivalent model to simulate the proppant migration under different parameter combinations, and calculate the effective propping coefficient;

[0129] Step S3: Based on the calculation results of the effective support coefficient, analyze the variation law of the effective support coefficient under different parameters and establish a distribution chart;

[0130] Step S4: Based on the distribution map, the pumping process is optimized using the optimal range of the effective support coefficient.

[0131] The difference between this embodiment and the above embodiments is that:

[0132] Figure 2 For the hydraulic fracture proppant migration model considering the bedding fractures of shale, in the step S2, the calculation formula of the effective support coefficient C is as follows:

[0133] C=∫∫ΔS·α

[0134] Where, Δs: microelement area, m 2 ; α: proppant volume coefficient of the microelement.

[0135] In the step S3, a distribution chart of effective support coefficient of vertical seams and a distribution chart of effective support coefficient of horizontal bedding fractures are established considering different sand amounts, displacements, particle sizes and particle size combinations.

[0136] Embodiment 4:

[0137] The present invention provides a pump injection design method based on an effective support coefficient, comprising the following steps:

[0138] Step S1: Establish a hydraulic fracture proppant migration model considering bedding fractures, with a half fracture length of 120 m, a fracture height of 30 m, a fracture width of 4 mm, and six bedding fractures developed, with the width of the four middle fractures being 2 mm and the width of the other two bedding fractures being 1 mm;

[0139] Step S2: Calculate the effective support coefficient under different displacement, sand volume, particle size and particle size combination, such as Figure 3 As shown in the figure, the calculation results of the effective support coefficient under different particle size combinations are as follows: Figure 4 Shown are the calculation results of sand concentration and different particle sizes;

[0140] Step S3: Based on the results of the previous step, combined with the actual construction parameters, the variation law of the effective support coefficient of vertical joints and bedding cracks under different parameters is analyzed, and a distribution chart is established, such as Figure 5 and Figure 6 As shown:

[0141] Step S4: Determine the advantage range of each parameter based on the results of the previous step: (1) The minimum displacement of a single cluster of fractures should meet 2.5-3m 3 / min; the amount of sand required for a single cluster of cracks is 25-30m 3 ; Under the condition of mixed particle size and sand addition, the proportion of 30 / 50 mesh proppant should be higher than 55%, the viscosity of the sand-carrying fluid with small and medium particle size (70 / 140 mesh, 40 / 70 mesh) is 5-20mPa.s, and the viscosity of the sand-carrying fluid with 30 / 50 mesh proppant should meet 30-50mPa.s; the pumping sand ratio of 70 / 140 mesh and 40 / 70 mesh should not exceed 15%, and the pumping sand ratio of 30 / 50 mesh should not exceed 25%. The optimized pumping procedure is as follows Figure 7 shown.

[0142] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A pumping design method based on effective support coefficient, characterized in that , including the following steps: Step S1: Based on the fluid-solid coupling theory, an equivalent model of proppant migration in hydraulic fractures considering bedding fractures is established; Step S2: with the goal of optimizing the paving area, using the hydraulic fracture proppant migration equivalent model to simulate the proppant migration under different parameter combinations, and calculate the effective propping coefficient; Step S3: Based on the calculation results of the effective support coefficient, analyze the variation law of the effective support coefficient under different parameters and establish a distribution chart; Step S4: Based on the distribution map, the pumping process is optimized using the optimal range of the effective support coefficient.

2. The pumping design method based on effective support coefficient according to claim 1 is characterized in that: In the step S1, the fluid-solid two-phase mass conservation equation of the fluid-solid coupling model of the proppant migration in the fracture is as follows: Where α f is the liquid volume fraction; α s is the volume fraction of the particle phase; ρ f is the liquid density, kg / m 3 ; ρ s is the particle phase density, kg / m 3 ; is the liquid phase linear velocity, m / s; is the particle phase linear velocity, m / s.

3. The pumping design method based on effective support coefficient according to claim 2 is characterized in that: The momentum conservation equation of the hydraulic fracture proppant migration equivalent model is as follows: Where: ▽ is the vector differential operator; τ f is the liquid shear stress tensor, τ s is the solid phase shear stress tensor, kg / (m·s 2 );ρ f is the liquid density, ρ s is the solid phase density, kg / m 3 ; is the acceleration due to gravity, -9.81m / s 2 ; Momentum exchange coefficient between β particles, kg / (m 3 ·s); p represents the pressure exerted by the fluid on the solid or the reaction force exerted by the solid on the fluid, Pa.

4. The pumping design method based on effective support coefficient according to claim 3 is characterized in that: In step S1, the variable density discrete phase model and discrete element coupling method are used to describe the flow of fracturing fluid and proppant in the fracture, momentum conversion is used to track the flow trajectory of particles, and Newton's momentum equation is used to describe each proppant particle in the flow field, and the force balance is achieved through the following equation: Where: F D is the particle drag coefficient per unit mass, s -1 ; is the particle collision force per unit mass related to the shear stress tensor, m / s 2 ; The unit is Basset force, m / s 2 ; is the lift, m / s 2 ;μ f is the fluid viscosity, Pa·s; d s is the particle diameter, mm; C D is the resistance coefficient, dimensionless; Re s is the Reynolds number.

5. The pumping design method based on effective support coefficient according to claim 3 is characterized in that: In step S1, the interaction between proppant particles is calculated using dense molecular dynamics theory, and the expression is: In the formula, τ s is the particle phase shear stress tensor, kg / (m·s 2 ); γ is the particle energy dissipation rate, kg·m -1 ·s -3 Φ is the interphase energy transfer caused by the change of particle velocity, kg·m -1 ·s -3 .

6. The pumping design method based on effective support coefficient according to claim 3 is characterized in that: In step S1, the Gidaspow drag force model is used to calculate the momentum exchange coefficient between the proppant particles, and the Johnson viscoelastic model is used to calculate the friction viscosity: Where P friction is the friction viscosity coefficient, dimensionless; α s,min is the minimum particle phase volume fraction, dimensionless; α s,max is the maximum particle phase volume fraction and is dimensionless.

7. The pumping design method based on effective support coefficient according to claim 3 is characterized in that: In step S1, according to the fluid flow rate during shale reservoir fracturing, the k-ε turbulence model is applied to process the fluid domain of the hydraulic fracture proppant migration equivalent model: Turbulent kinetic energy equation: Dissipation rate equation: In the formula, Π k is the turbulent exchange term between turbulent kinetic energy, Π ε is the turbulent exchange term between dissipation rates, kg / (m·s 3 ), k is the turbulent kinetic energy, m 2 / s 2 ; σ k is the turbulent Prandtl number for the turbulent kinetic energy k, dimensionless; σ ε is the turbulent Prandtl number of the dissipation rate ε, dimensionless; G k,f is the turbulent kinetic energy, kg / (m·s 3 ); μ t is the fluid shear viscosity, Pa·s; ε is the dissipation rate, m 2 / s 3 ; C1, C2 are constants.

8. The pumping design method based on effective support coefficient according to claim 3 is characterized in that: In the step S1, the particle acceleration is affected by a force parallel to the particle movement direction, and the proppant flow is affected by gravity, drag force, particle collision force, virtual force and Basset force.

9. The pumping design method based on effective support coefficient according to claim 8, characterized in that: The calculation formula of gravity is: In the formula, F g Gravity, m / s 2 .

10. The pumping design method based on effective support coefficient according to claim 8, characterized in that: The calculation formula of the drag force is: In the formula, F s is the drag force, m / s 2 ; C S A is the drag force coefficient between the two phases, dimensionless; s is the particle surface area, mm 2 ; V S is the particle phase velocity, m / s.

11. The pumping design method based on effective support coefficient according to claim 8, characterized in that: The calculation formula of the particle collision force is: In the formula, F c is the particle collision force, m / s 2 .

12. The pumping design method based on effective support coefficient according to claim 8, characterized in that: The calculation formula of the virtual force is: In the formula, F vm is the virtual force, m / s 2 ;v f is the liquid phase velocity.

13. The pumping design method based on effective support coefficient according to claim 8, characterized in that: The calculation formula of the Basset force is: In the formula, F B is the Basset force, m / s 2 ; t is time, s; t′ is the reference time, s.

14. The pumping design method based on effective support coefficient according to claim 1, characterized in that: In step S2, the calculation formula of the effective support coefficient C is as follows: C=∫∫ΔS·α Where, Δs: microelement area, m 2 ; α: proppant volume coefficient of the microelement.

15. The pumping design method based on effective support coefficient according to claim 1, characterized in that: In the step S3, a distribution chart of effective support coefficient of vertical seams and a distribution chart of effective support coefficient of horizontal bedding fractures are established considering different sand amounts, displacements, particle sizes and particle size combinations.

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