Compact oil and gas reservoir multi-scale crack global supporting and efficient laying method

Abstract

The invention relates to a dense oil and gas reservoir multi-scale crack global supporting and efficient laying method, which comprises the following steps of S1, performing grading evaluation on a multi-scale crack network based on a multi-scale crack expansion model, and obtaining a distribution condition of the multi-scale crack network; s2, setting evaluation indexes for the proppant to enter the multi-scale crack network, and determining crack entering conditions of the proppant in cracks of different scales; and S3, establishing a proppant particle conveying model in the multi-scale crack, and optimizing a proppant material and crack entering process parameters. According to the method, the hydraulic fracturing construction parameter design is optimized from the angles of the crack propagation form, the propping agent crack entering condition and the matched propping agent needed by all levels of cracks, the problems of tight reservoir multi-scale crack global supporting and efficient laying are solved, the calculation cost is low, and the operation efficiency is high.

Description

Technical Field

[0001] The present invention relates to the technical field of petroleum engineering, and in particular to a method for global support and efficient laying of multi-scale fractures in tight oil and gas reservoirs. Background Art

[0002] Energy is the key to driving the rapid development of the world economy today. Since the 21st century, oil and gas resources have become the main body of global primary energy consumption, accounting for more than 60%. With more than a hundred years of oil and gas exploration and development, the amount of oil and gas resources in the world's "conventional" medium and high permeability reservoirs has been greatly reduced. In recent years, tight oil and gas reservoirs have become a hot spot in the field of oil and gas resource exploration and development. Hydraulic fracturing is an important measure to increase the production of tight oil and gas reservoirs. It mainly injects high-pressure liquid (pre-fluid) into the reservoir under the condition of higher than the reservoir fracture pressure or the natural fracture closure pressure, generates hydraulic fractures in the reservoir and communicates with natural fractures. The hydraulic fractures and natural fractures are intertwined to form a multi-scale complex fracture network (main fractures, branch fractures, micro fractures). Then continue to inject fracturing fluid (sand-carrying fluid) with proppant. The proppant enters the main fracture, branch fracture and micro fracture from the wellbore under the fracturing fluid, and gradually settles to form a sand bank. After the fracturing fluid is lost or flowed back, the proppant remaining in the fracture can prevent the fracture from closing completely, so that the multi-stage fractures can still maintain a certain degree of openness under the closing pressure, forming propped fractures with a certain width in the formation that allow fluid flow. The high conductivity of the propped fractures can be used to improve the oil and gas seepage conditions, thereby increasing the production capacity of the oil and gas wells.

[0003] In response to the engineering problems of low production and short stable production period after hydraulic fracturing of tight reservoirs, studies have shown that whether proppants can be efficiently laid in multi-scale fractures and the effectiveness of supporting fracture networks is the key to high and stable production of tight reservoirs. During hydraulic fracturing, proppants in multi-scale fractures have problems such as "not being able to be transported far, not being fully laid, and not being able to hold up". Under high formation closure stress conditions, unsupported fractures are easy to close, resulting in a reduction in effective fracture length, causing rapid decline in oil and gas reservoir production after fracturing and difficulty in stabilizing production. These engineering problems need to be solved urgently.

[0004] In the existing technology, domestic and foreign scholars have conducted research on fracture expansion, proppant delivery, conductivity evaluation and construction parameter optimization in the field of hydraulic fracturing of tight oil and gas reservoirs. However, there is a lack of relevant theoretical research on the conductivity requirements and matching proppant dosage between different levels of fractures (main fractures, branch fractures, micro fractures) in multi-scale fractures. It cannot meet the current requirements for long-term conductivity of multi-scale fractures in hydraulic fracturing of tight reservoirs, and cannot provide effective guidance for hydraulic fracturing optimization. As a result, most of the on-site construction parameters are still recommended based on experience, and the problem of rapid production decline and difficulty in stabilizing production in tight oil and gas reservoirs after fracturing has not been effectively solved. Summary of the invention

[0005] The present invention provides a method for full-area support and efficient paving of multi-scale fractures in tight oil and gas reservoirs. The method optimizes the design of hydraulic fracturing construction parameters based on the fracture extension morphology, proppant entry conditions, sand concentration required for each level of fractures, and matching proppant dosage to achieve full-area support and efficient paving of multi-scale fractures. To achieve the above purpose, the present invention provides the following solutions:

[0006] A method for global support and efficient paving of multi-scale fractures in tight oil and gas reservoirs, comprising the following steps:

[0007] S1: Based on the multi-scale fracture propagation model, the multi-scale fracture network is graded and evaluated and its distribution is obtained;

[0008] S2: Setting the evaluation index of proppant entering the multi-scale fracture network and determining the entry conditions of proppant into fractures of different scales;

[0009] S3: Establish a proppant particle transport model in multi-scale fractures and optimize proppant materials and fracture entry process parameters.

[0010] Furthermore, the step S1 also includes:

[0011] Multi-scale fracture networks were graded and evaluated based on fracture width.

[0012] Furthermore, the step S1 also includes:

[0013] The multi-scale crack network includes main cracks, branch cracks and micro cracks. The crack width of the main crack is greater than the crack width of the branch crack, and the crack width of the branch crack is greater than the crack width of the micro crack.

[0014] Furthermore, the crack width of the main seam is greater than 5 mm, the crack width of the branch seam is 1 to 5 mm, and the crack width of the micro seam is less than 1 mm.

[0015] Furthermore, the evaluation index in step S2 includes proppant penetration rate, and the method for obtaining the proppant penetration rate is:

[0016]

[0017] In the formula, λ e is the proppant penetration rate, m; m p The amount of proppant entering the wellbore or main seam or branch seam, kg; m t is the mass of proppant entering the next level fracture, kg.

[0018] Furthermore, when the slot rate λ e When it is >30%, the proppant can enter the next level fracture from the previous level fracture.

[0019] Furthermore, in step S3, optimization is performed by an orthogonal experimental method.

[0020] Furthermore, the proppant material parameters include proppant particle size, and the seam entry process parameters include average sand ratio, fracturing fluid viscosity and construction pump injection and displacement.

[0021] On the other hand, the present invention provides a system for global support and efficient paving of multi-scale fractures in tight oil and gas reservoirs, comprising the following units:

[0022] A multi-scale fracture parameter acquisition unit configured to obtain a multi-scale fracture network classification evaluation and its distribution;

[0023] A proppant entry evaluation unit, configured to set an evaluation index for proppant entry into a multi-scale fracture network and determine the entry conditions of proppant into fractures of different scales;

[0024] The parameter optimization unit is configured to optimize the proppant material and the seam entry process parameters.

[0025] On the other hand, the present invention provides a computer-readable storage medium having instructions stored thereon, which, when executed by a processor, causes the processor to execute the method for global support and efficient laying of multi-scale fractures in tight oil and gas reservoirs as described in any one of the above claims.

[0026] The present invention has the following advantages: the present invention optimizes the design of hydraulic fracturing construction parameters from the perspectives of crack expansion morphology, proppant entry conditions, and proppant matching requirements for each level of cracks, thereby solving the problem of global support and efficient laying of multi-scale cracks in tight reservoirs. It does not require the use of large-scale commercial software for numerical simulation, has low calculation costs, and high operating efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0028] Figure 1 It is a schematic diagram of the method flow of the present invention;

[0029] Figure 2 A schematic diagram of a multi-scale fracture network in an embodiment of the present invention;

[0030] Figure 3 Schematic diagram of a tight oil reservoir injection and production well group in an embodiment of the present invention;

[0031] Figure 4Schematic diagram of a multi-scale fracture network of a tight oil and gas reservoir in an embodiment of the present invention;

[0032] Figure 5 Schematic diagram of optimization results of seam entry process parameters in an embodiment of the present invention. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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.

[0034] The purpose of the present invention is to provide a method for global support and efficient laying of multi-scale fractures in tight oil and gas reservoirs. In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0035] In order to solve the technical problems of "not being able to transport far enough, not being able to spread enough, and not being able to support" when transporting proppant in multi-scale network fractures of tight oil and gas reservoirs, the technical effects of full-area support and efficient laying of proppant in multi-scale fractures are achieved. Figure 1 As shown, the present invention provides a method for global support and efficient paving of multi-scale fractures in tight oil and gas reservoirs, comprising the following steps:

[0036] S1: Based on the multi-scale fracture propagation model, the multi-scale fracture network is graded and evaluated and its distribution is obtained;

[0037] During the hydraulic fracturing process of tight oil and gas reservoirs, hydraulic fractures are generated in the reservoir and connect with natural fractures. The hydraulic fractures and natural fractures are intertwined to form a multi-scale complex fracture network. Figure 2 As shown, the multi-scale fracture network can be divided into fractures of different levels according to the fracture width parameter. Those skilled in the art can classify fractures of different levels into main fractures, branch fractures and micro fractures.

[0038] Specifically, in practical applications, technicians in this field can obtain the multi-scale fracture network extension morphology through the fracture extension model, and based on the multi-scale fracture classification standard, they can count and analyze the multi-scale fracture network classification.

[0039] S2: Setting the evaluation index of proppant entering the multi-scale fracture network and determining the entry conditions of proppant into fractures of different scales;

[0040] During the proppant transmission process, the physical process of its entry into the fracture is: the proppant enters the main fracture from the wellbore, enters the branch fracture from the main fracture, and enters the micro fracture from the branch fracture under the sand-carrying fluid. The ideal proppant effect is that the proppant can achieve efficient entry and effective support in all levels of fractures. Therefore, in order to achieve the best match between the conductivity requirements and proppant dosage between different levels of fractures (main fracture, branch fracture, micro fracture), it is necessary to set corresponding fracture entry conditions for different levels of fractures.

[0041] Specifically, the ratio of the amount of proppant entering the wellbore, main fracture and branch fracture to the mass entering the next-level fracture (i.e., main fracture, branch fracture and micro fracture, respectively) (i.e., fracture penetration rate) can be used as an evaluation index.

[0042] S3: Establish a proppant particle transport model in multi-scale fractures and optimize proppant materials and fracture entry process parameters.

[0043] In specific applications, technicians in this field can establish a proppant particle transport model in multi-scale fractures according to the working conditions, design orthogonal experiments, and optimize the proppant material and fracture entry process parameters through numerical simulation, including proppant particle size, average sand ratio, fracturing fluid viscosity, and construction pump injection and discharge volume.

[0044] In one embodiment, when determining the multi-scale fracture classification standard, those skilled in the art may classify fractures of different scales according to the classification standard in Table 1.

[0045] Table 1 Multi-scale crack classification standards

[0046]

[0047] In one embodiment, the penetration rate of the proppant is used to evaluate the penetration process of the proppant.

[0048]

[0049] In the formula, λ e is the proppant penetration rate, m; m p The amount of proppant entering the wellbore or main seam or branch seam, kg; m t It is the mass of proppant entering the next level fracture (main fracture, branch fracture or micro fracture), kg.

[0050] In specific applications, those skilled in the art can define the conditions for proppant penetration into fractures of different scales based on indoor research results and field implementation experience. In a preferred embodiment, when the penetration rate λ e When it is >30%, it is considered that the proppant can enter the next level fracture from the previous level fracture.

[0051] In one embodiment, when optimizing proppant materials and slotting process parameters, the following steps are included:

[0052] (S310) establishing a fracturing fluid phase control model, wherein the fracturing fluid phase control model mainly includes a mass conservation equation and a momentum conservation equation;

[0053] (S320) establishing a proppant particle motion model, wherein the proppant particle motion model mainly includes a translation equation and a rotation equation of proppant motion;

[0054] (S330) Based on the proppant particle transport model in multi-scale fractures, an orthogonal experiment is designed to optimize the proppant entry conditions through numerical simulation, including proppant particle size, average sand ratio, fracturing fluid viscosity, and construction pumping rate.

[0055] In one embodiment, when establishing a fracturing fluid phase control model, the following steps are included:

[0056] Assuming that the fluid temperature and rheological properties do not change during the simulation process and the fluid is incompressible, a fracturing fluid phase control model is established based on the Navier-Stokes equations. Its main equations include the mass conservation equation and the momentum conservation equation.

[0057] The mass conservation equation is shown in formula (2).

[0058]

[0059] Where: is the differential symbol; is the Laplace operator; t is the fluid flow time, s; ρ l is the fluid phase density, kg / m 3 ; ε l is the volume fraction of the fluid phase, %; u l is the fluid phase flow velocity, m / s.

[0060] The momentum conservation equation is shown in equation (3).

[0061]

[0062] Where: P is the flow field pressure in the crack, Pa; g is the gravitational acceleration, 9.8m / s 2 ;M pl is the momentum exchange source term between the fracturing fluid and the proppant particles.

[0063] In one embodiment, establishing a proppant particle motion model includes the following steps:

[0064] Considering the forces between proppant particles, a proppant particle motion model is established, which mainly includes the translation equation and rotation equation of proppant motion.

[0065] The proppant translation equation is shown in formula (4):

[0066]

[0067] Where: ∑ is the summation symbol; m p,i is the mass of particle i, kg; u p,i is the velocity of particle i, m / s; F pc,ij is the contact force between particles i and j, N; F lp,i is the force exerted by the fluid on particle i, N.

[0068] The proppant rotation equation is shown in formula (5):

[0069]

[0070] Where: I pc,ij is the moment of inertia of particle i, kg·m 2 ;ω p,i is the angular velocity of particle i, rad / s; T pc,ij is the contact torque generated between particles i and j, N·m.

[0071] In one embodiment, the method for global support and efficient laying of multi-scale fractures in tight oil and gas reservoirs proposed in the present invention is used to establish a reservoir seepage model for low-permeability tight oil and gas reservoirs, introduce the multi-scale fracture extension network morphology, and optimize the multi-scale fracture network conductivity with the maximum recovery rate of the oil and gas reservoir as the goal. Specifically, the following steps are included:

[0072] Assuming that the production well is a constant pressure production and the injection well is a constant pressure or quantitative injection, the fluid flow equation under the matrix-fracture condition in the tight oil and gas reservoir is established. The fluid flow equation mainly includes the fluid flow equation in the matrix and fracture.

[0073] Based on the reservoir seepage model of low permeability tight oil and gas reservoirs, an orthogonal experiment was designed to optimize the conductivity of multi-scale fracture networks through numerical simulation with the maximum recovery rate of oil and gas reservoirs as the goal. ct .

[0074] In one embodiment, the method for global support and efficient paving of multi-scale fractures in tight oil and gas reservoirs proposed in the present invention is used to optimize the proppant paving concentration required for each level of fractures and the proppant dosage that matches them. Specifically, the method includes the following steps:

[0075] Combined with the size of each level of fracture, calculate the proppant dosage M corresponding to each level of fracture p , the calculation formula is as shown in formula (6).

[0076] M p,i =S f,i C p,i(6)

[0077] Where: M p,i is the amount of proppant required for the i-th level fracture, kg; S f,i is the surface area corresponding to the i-th crack, m 2 ; C p,i is the proppant concentration in the i-th fracture, kg / m 2 ; i is any level of crack, including main crack, branch crack and micro crack.

[0078] Based on the same inventive concept, the embodiment of the present invention also provides a system for global support and efficient paving of multi-scale fractures in tight oil and gas reservoirs, which is used to implement the above-mentioned method embodiment for global support and efficient paving of multi-scale fractures in tight oil and gas reservoirs. The system includes:

[0079] A multi-scale fracture parameter acquisition unit configured to obtain a multi-scale fracture network classification evaluation and its distribution;

[0080] A proppant entry evaluation unit, configured to set an evaluation index for proppant entry into a multi-scale fracture network and determine the entry conditions of proppant into fractures of different scales;

[0081] The parameter optimization unit is configured to optimize the proppant material and the seam entry process parameters.

[0082] The embodiment of the present invention also provides a computer-readable storage medium capable of implementing all steps in the method for global support and efficient paving of multi-scale fractures in tight oil and gas reservoirs in the above embodiment. The computer-readable storage medium stores a computer program. When the computer program is executed by a processor, all steps of the method for global support and efficient paving of multi-scale fractures in the above embodiment are implemented. For example, when the processor executes the computer program, the following steps are implemented:

[0083] S1: Based on the multi-scale fracture propagation model, the multi-scale fracture network is graded and evaluated and its distribution is obtained;

[0084] S2: Setting the evaluation index of proppant entering the multi-scale fracture network and determining the entry conditions of proppant into fractures of different scales;

[0085] S3: Establish a proppant particle transport model in multi-scale fractures and optimize proppant materials and fracture entry process parameters.

[0086] Example 1

[0087] This embodiment provides a method for global support and efficient placement of multi-scale fractures in tight oil and gas reservoirs, which is used to optimize global support and efficient placement of multi-scale fractures in block B of a low-permeability tight oil reservoir in a certain oil field.

[0088] The basic geological parameters of the low permeability tight oil reservoir in Block B are shown in Table 2. Figure 3 As shown, there is 1 water injection well and 4 oil production wells, of which the water injection well injects a fixed amount of liquid (30m 3 / d), the oil wells are produced at a fixed production pressure difference (5MPa). The oil wells are put into production after being transformed by hydraulic fracturing. From the perspective of efficient laying of multi-size proppants, full-area support of multi-scale fractures, and long-term maintenance of the conductivity of multi-level support fractures, the hydraulic fracturing construction parameters are optimized to ensure high and stable production of tight oil reservoirs.

[0089] Table 2 Reservoir geological parameters

[0090]

[0091] The optimization process includes the following steps:

[0092] (1) Based on the multi-scale crack propagation model, the multi-scale crack network is graded and evaluated and its distribution is obtained.

[0093] According to the multi-scale fracture network expansion morphology obtained by the fracture extension model, the multi-scale fracture network is divided into different levels of fractures according to the fracture width, such as Figure 3 As shown, it includes main seams, branch seams and micro seams, and the classification standards are shown in Table 1.

[0094] Based on the multi-scale crack classification standard, the multi-scale crack network classification was statistically analyzed. As shown in Table 3, the average width of the main crack is 7.65 mm, accounting for 50.07% of the crack volume; the average width of the branch crack is 2.51 mm, accounting for 33.66% of the crack volume; the average width of the micro crack is 0.74 mm, accounting for 16.27% of the crack volume.

[0095] Table 3 Multi-scale crack classification

[0096]

[0097]

[0098] (2) Set evaluation indicators for proppant entry into multi-scale fracture networks and determine the entry conditions of proppant into fractures of different scales.

[0099] The calculation formula (1) in the present invention is used as the evaluation index. When the seam penetration rate λ e When it is >30%, it is considered that the proppant can enter the next level fracture from the previous level fracture.

[0100] (3) Establish a proppant particle transport model in multi-scale fractures and optimize proppant materials and fracture insertion process parameters.

[0101] Based on the proppant particle transport model in multi-scale fractures, an orthogonal experiment was designed, as shown in Table 4. Taking the proppant entry condition (entry rate greater than 30%) as the target, the proppant material and entry process parameters were optimized through numerical simulation, including proppant particle size, average sand ratio, fracturing fluid viscosity, and construction pumping displacement. The optimization results are shown in Table 4. Figure 3 As shown in the figure, the optimization results of proppant particle size in main fracture, branch fracture and micro fracture are 40 / 70 mesh, 70 / 140 mesh and 100 / 200 mesh respectively; the optimization results of average sand ratio in main fracture, branch fracture and micro fracture are 12%, 10% and 6% respectively; the optimization results of fracturing fluid viscosity in main fracture, branch fracture and micro fracture are 3mPa·s, 5mPa·s and 9mPa·s respectively; the optimization results of construction pumping displacement in main fracture, branch fracture and micro fracture are 8m 3 / min、12m 3 / min、14m 3 / min.

[0102] Table 4 Orthogonal experimental analysis factors and values ​​of seam entry process parameters

[0103]

[0104] Based on the reservoir seepage model of low permeability tight oil and gas reservoirs, considering the influence of main fractures, branch fractures and micro fractures, an orthogonal experiment was designed, as shown in Table 5. With the maximum recovery of oil and gas reservoir as the target, the conductivity of multi-scale fracture network was optimized through numerical simulation. The optimization results are as follows: the main fracture conductivity F ct,m 30D·cm, branch seam conductivity F ct,b The micro-slit flow conductivity is 10D·cm, and the micro-slit flow conductivity is F ct,w is 2D·cm.

[0105] Table 5 Orthogonal experimental analysis factors and values ​​for flow conductivity test

[0106]

[0107] Based on the multi-scale fracture conductivity obtained above, the proppant concentration required for each level of fracture and the matching proppant dosage are calculated.

[0108] Based on the optimization result of the multi-scale fracture network conductivity obtained in step (4), the calculation method of the conductivity of the interactive sand-filled fracture proposed in the invention patent CN202110164326.4 is used to calculate the overall conductivity of the multi-scale fracture network F ct =23.64D·cm, and the required proppant concentration C in each level of fracture (main fracture, branch fracture, micro fracture) is calculated at the same time. p , the calculation is shown in Table 6.

[0109] Table 6 Multi-scale fracture sand concentration and proppant dosage

[0110]

[0111] Comparing the calculation results in Table 3 and Table 6, the proportion of proppant usage in each level of fractures is consistent with the proportion of fracture volume, indicating that the global support and efficient laying technology for multi-scale fractures in tight oil and gas reservoirs proposed in the present invention can achieve the transformation goal of proppant "entering, laying fully, and supporting" in multi-scale fractures, meet the long-term conductivity of multi-scale supported fractures, and ensure high and stable production of oil and gas reservoirs.

[0112] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for global support and efficient paving of multi-scale fractures in tight oil and gas reservoirs, comprising the following steps: S1: Based on the multi-scale fracture propagation model, the multi-scale fracture network is graded and evaluated and its distribution is obtained; S2: Setting the evaluation index of proppant entering the multi-scale fracture network and determining the entry conditions of proppant into fractures of different scales; S3: Establish a proppant particle transport model in multi-scale fractures and optimize proppant materials and fracture entry process parameters.

2. The method for global support and efficient paving of multi-scale fractures in tight oil and gas reservoirs according to claim 1, wherein step S1 further comprises: Multi-scale fracture networks were graded and evaluated based on fracture width.

3. The method for global support and efficient paving of multi-scale fractures in tight oil and gas reservoirs according to claim 1, wherein step S1 further comprises: The multi-scale crack network includes main cracks, branch cracks and micro cracks. The crack width of the main crack is greater than the crack width of the branch crack, and the crack width of the branch crack is greater than the crack width of the micro crack.

4. The method for global support and efficient laying of multi-scale fractures in tight oil and gas reservoirs as described in claim 3, wherein the width of the main fracture is greater than 5 mm, the width of the branch fracture is 1 to 5 mm, and the width of the micro fracture is less than 1 mm.

5. The method for global support and efficient paving of multi-scale fractures in tight oil and gas reservoirs according to claim 1, wherein the evaluation index in step S2 includes a proppant penetration rate, and the method for obtaining the proppant penetration rate is: In the formula, λ e is the proppant penetration rate, m; m p The amount of proppant entering the wellbore or main seam or branch seam, kg; m t is the mass of proppant entering the next level fracture, kg.

6. The method for global support and efficient paving of multi-scale fractures in tight oil and gas reservoirs according to claim 5, when the fracture penetration rate λ e When it is >30%, the proppant can enter the next level fracture from the previous level fracture.

7. The method for global support and efficient placement of multi-scale fractures in tight oil and gas reservoirs as claimed in claim 1, wherein the optimization in step S3 is performed by an orthogonal experimental method.

8. The method for global support and efficient laying of multi-scale fractures in tight oil and gas reservoirs as described in claim 1, wherein the proppant material parameters include proppant particle size, and the fracture entry process parameters include average sand ratio, fracturing fluid viscosity, and construction pump injection and displacement.

9. A multi-scale fracture global support and efficient paving system for tight oil and gas reservoirs, comprising the following units: A multi-scale fracture parameter acquisition unit configured to obtain a multi-scale fracture network classification evaluation and its distribution; a proppant entry evaluation unit, configured to set an evaluation index for proppant entry into a multi-scale fracture network and determine the entry conditions of proppant into fractures of different scales; The parameter optimization unit is configured to optimize the proppant material and the seam entry process parameters.

10. A computer-readable storage medium having instructions stored thereon, which, when executed by a processor, causes the processor to execute the method for global support and efficient laying of multi-scale fractures in tight oil and gas reservoirs as described in any one of claims 1 to 8.

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