Shale fracturing complex fracture conductivity determination method and device and electronic equipment

Abstract

The invention relates to the technical field of oil and gas field development engineering, and discloses a shale fracturing complex fracture conductivity determination method and device and electronic equipment, and the method comprises the steps: predicting a complex fracture distribution form of a target reservoir after hydraulic fracturing; establishing a proppant migration geometric model according to the complex fracture distribution form, and executing a proppant migration paving numerical simulation operation according to the proppant migration geometric model under preset geological factor conditions and preset engineering factor conditions to obtain a numerical simulation result; according to a numerical simulation result, the complex crack area is divided into an effective supporting crack area and a self-supporting crack area; according to a preset effective support fracture conductivity calculation model, a preset self-support fracture conductivity calculation model and the numerical simulation result, the fracture conductivity of the effective support fracture area and the fracture conductivity of the self-support fracture area are determined respectively. According to the method, the flow conductivity of the whole deep shale complex fracture system can be obtained more accurately.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas field development engineering, and in particular to a method, a device and an electronic device for determining the conductivity of complex fractures in shale fracturing. Background Art

[0002] Shale oil and gas reserves are abundant in my country, accounting for a significant proportion of my country's annual new oil and gas reserves. However, the permeability of shale reservoirs is extremely low, so hydraulic fracturing technology must be used to transform the reservoirs to form a complex fracture system and provide a flow channel for shale oil and gas.

[0003] Fracture conductivity is one of the key parameters that determine the effect of hydraulic fracturing. Especially for deep shale reservoirs, natural fractures are relatively developed. After hydraulic fracturing, hydraulic fractures communicate with natural fractures, forming a complex fracture network in which the main fractures interact with secondary fractures and natural fractures. The migration ability of proppants in the main fractures, secondary fractures and natural fractures is different, which also causes the distribution pattern of proppants in the complex fracture system composed of main fractures, secondary fractures and natural fractures to be different. The distribution pattern of proppants in complex fractures determines the conductivity of fractures. The main fracture width is large, and proppants are easy to migrate and lay in it, thus forming a higher sand laying concentration and a larger laying range. The secondary fracture width is narrow, and the migration and laying ability of proppants in it is reduced, and the sand laying concentration and laying range become smaller. Natural fractures are at the end of the complex fracture system, and whether proppants can effectively enter the natural fractures and open them is a challenge. Some natural fractures and fractures that are not effectively supported by proppants will exist in a self-supporting form. The conductivity of such self-supporting fractures is much lower than the conductivity of effectively supported fractures. Especially under the high closure pressure of deep shale, the conductivity of self-supporting fractures will be greatly reduced. In addition, the high closure pressure of deep shale also affects the proppant in the effective support fracture, which is manifested in the embedding, crushing and creep of the proppant under high closure pressure. Therefore, the conductivity of complex fractures in deep shale is closely related to the distribution of complex fractures, the laying form of proppant in the fracture, and the embedding, crushing and creep of proppant under high closure pressure.

[0004] At present, the research on the conductivity of shale fractures has ignored the placement of proppants in the complex fracture morphology of shale. The conductivity test in a single main fracture is directly carried out using two parallel rock plates, or theoretical calculations are performed based on the parallel rock plate model. However, the placement of proppants is different under different fracture distributions, which leads to different conductivity of fractures of different orders in the complex fracture system of shale. The simple test results of parallel rock plates and model calculation results are obviously not able to replace the conductivity of the entire complex fracture system of shale.

[0005] Therefore, a new method for determining the conductivity of complex fractures in shale fracturing is urgently needed to solve the above problems. Summary of the invention

[0006] In view of the above problems, the present invention provides a method, device and electronic equipment for determining the conductivity of complex fractures in shale fracturing, which comprehensively considers the distribution morphology of complex fractures and the laying morphology of proppant, divides the complex fracture area into an effective supporting fracture area and a self-supporting fracture area, and determines the corresponding conductivity of the effective supporting fracture area and the self-supporting fracture area respectively. Therefore, when determining the conductivity of complex fractures in deep shale fracturing, it is not limited to determining the conductivity within a single main fracture, but can accurately obtain the conductivity of the entire deep shale complex fracture system.

[0007] The present invention provides a method for determining the conductivity of complex fractures in shale fracturing, the method comprising:

[0008] Construct a geological model and predict the complex fracture distribution of the target reservoir after hydraulic fracturing based on the preset fracturing construction strategy;

[0009] Establish a proppant migration geometry model according to the complex fracture distribution morphology, and perform proppant migration and paving numerical simulation operations according to the proppant migration geometry model under preset geological factors and preset engineering factors to obtain numerical simulation results;

[0010] According to the numerical simulation results, the complex fracture area is divided into effective support fracture area and self-support fracture area;

[0011] According to the preset calculation model of effective supported fracture conductivity, the preset calculation model of self-supported fracture conductivity and the numerical simulation results, the fracture conductivity of the effective supported fracture zone and the fracture conductivity of the self-supported fracture zone are determined respectively.

[0012] Furthermore, there are multiple preset engineering factor conditions; under the preset geological factor conditions and the preset engineering factor conditions, the proppant migration and paving numerical simulation operation is performed according to the proppant migration geometric model, including:

[0013] According to the same preset geological factor condition, multiple proppant migration and laying numerical simulation operations are performed according to the proppant migration geometric model under different preset engineering factor conditions to obtain numerical simulation results under different preset engineering factor conditions;

[0014] The effective support crack area includes: the effective support crack area under different preset engineering factors;

[0015] The self-supporting crack zone includes: the self-supporting crack zone under different preset engineering factor conditions.

[0016] Furthermore, the method further comprises:

[0017] Taking the deep shale of the target reservoir as the test sample, a variety of effective support test conditions are preset; wherein the effective support test conditions include closure pressure conditions, pressure difference conditions, flow conditions, engineering factor conditions and proppant migration and laying results corresponding to the engineering factor conditions, and the engineering factor conditions and the proppant migration and laying results corresponding to the engineering factor conditions are determined according to the preset engineering factor conditions and numerical simulation results in the proppant migration and laying numerical simulation operation;

[0018] The closing pressure condition, the pressure difference condition and the flow condition in each effective support test condition are used as self-support test conditions to obtain a variety of self-support test conditions;

[0019] Conducting effective support fracture conductivity tests and self-support fracture conductivity tests on the test samples under a variety of effective support test conditions and a variety of self-support test conditions, respectively, to obtain conductivity test results under each effective support test condition and each self-support test condition;

[0020] According to each effective support test condition and its conductivity test result and each self-support test condition and its conductivity test result, a preset effective support crack conductivity calculation model and a preset self-support crack conductivity calculation model are established.

[0021] Furthermore, according to the preset effective supported fracture conductivity calculation model, the preset self-supported fracture conductivity calculation model and the numerical simulation results, the fracture conductivity of the effective supported fracture area and the fracture conductivity of the self-supported fracture area are determined respectively, including:

[0022] Dividing the complex crack region into a plurality of grid units of preset sizes;

[0023] According to the preset effective support fracture conductivity calculation model and numerical simulation results, the fracture conductivity of each grid unit in the effective support fracture area is determined;

[0024] According to the preset self-supporting fracture conductivity calculation model and numerical simulation results, the fracture conductivity of each grid unit in the self-supporting fracture area is determined;

[0025] Among them, the numerical simulation results include the number and position of proppant particles. The grid cells with the number of proppant particles greater than the preset number threshold are regarded as grid cells in the effective supported fracture zone, and the grid cells with the number of proppant particles not greater than the preset number threshold are regarded as grid cells in the self-supported fracture zone.

[0026] Furthermore, the preset effective support fracture conductivity calculation model includes:

[0027]

[0028] Among them, F RCD To effectively support the fracture conductivity;

[0029] c0 is the correction coefficient;

[0030] D is the fracture opening when the fracture is closed and pressurized onto the proppant when the closing pressure is 0;

[0031] α(t) is the deformation of the fracture width over time due to proppant creep;

[0032] φ(t) is the variation of porosity with time due to proppant creep;

[0033] r(t) is the deformation of the pore due to proppant creep over time;

[0034] τ(t) is the variation of tortuosity over time;

[0035] K1, K2, K3 and K4 are all constants.

[0036] Furthermore, the preset self-supporting fracture conductivity calculation model includes:

[0037]

[0038] Among them, F CD is the conductivity of the self-supporting fracture;

[0039] Q is the volume flow rate of sand-carrying fluid;

[0040] δ is the ratio of crack length to height;

[0041] P0, P1, and P2 are atmospheric pressure, fracture inlet pressure, and fracture outlet pressure, respectively;

[0042] K5, K6 and K7 are all constants.

[0043] The present invention also provides a method for determining a shale fracturing complex fracture conductivity cloud map, the method comprising:

[0044] Determine the complex fracture conductivity of the target reservoir according to the above-mentioned method for determining the complex fracture conductivity of shale fracturing; wherein the complex fracture conductivity includes the fracture conductivity of the effective supporting fracture zone and the fracture conductivity of the self-supporting fracture zone;

[0045] The complex fracture conductivity cloud map is determined based on the complex fracture conductivity.

[0046] The present invention also provides a device for determining the conductivity of complex fractures in shale fracturing, the device comprising:

[0047] The prediction module is used to construct a geological model and predict the complex fracture distribution of the target reservoir after hydraulic fracturing according to the preset fracturing construction strategy;

[0048] A numerical simulation module is used to establish a proppant migration geometry model according to the complex fracture distribution morphology, and to perform a proppant migration and paving numerical simulation operation according to the proppant migration geometry model under preset geological factors and preset engineering factors to obtain numerical simulation results;

[0049] A region division module is used to divide the complex fracture region into an effective support fracture region and a self-support fracture region according to the numerical simulation results;

[0050] The conductivity determination module is used to determine the fracture conductivity of the effective supported fracture area and the fracture conductivity of the self-supported fracture area according to a preset effective supported fracture conductivity calculation model, a preset self-supported fracture conductivity calculation model and numerical simulation results.

[0051] The present invention also provides a computer-readable storage medium, wherein the computer program stored in the computer-readable storage medium implements the steps of the above method when executed by one or more processors.

[0052] The present invention also provides an electronic device, comprising a memory and one or more processors, wherein a computer program is stored in the memory, and when the computer program is executed by the one or more processors, the steps of the above method are executed.

[0053] The method, device and electronic equipment for determining the conductivity of complex fractures in shale fracturing provided by the present invention, when determining the conductivity of complex fractures, first predict the complex fracture distribution morphology of the target reservoir after hydraulic fracturing, and perform numerical simulation of proppant migration and laying according to the complex fracture distribution morphology, so as to divide the complex fracture area into an effective support fracture area and a self-support fracture area according to the numerical simulation results, and respectively use a preset effective support fracture conductivity calculation model and a preset self-support fracture conductivity calculation model to calculate the conductivity of the effective support fracture area and the self-support fracture area, and the entire determination process comprehensively considers the complex fracture distribution morphology and the proppant laying morphology, so that the conductivity of the entire deep shale complex fracture system can be obtained more accurately. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] 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 or the description of the prior art 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 work.

[0055] Figure 1The method for determining the conductivity of complex fractures in shale fracturing in the first embodiment of the present invention is as follows: Figure 1 .

[0056] Figure 2 Schematic diagram of complex crack distribution.

[0057] Figure 3 Schematic diagram of proppant migration and placement in complex fractures.

[0058] Figure 4 The method for determining the conductivity of complex fractures in shale fracturing in the first embodiment of the present invention is as follows: Figure 2 .

[0059] Figure 5 This is a flow chart of the steps of a method for determining a shale fracturing complex fracture conductivity cloud map in Embodiment 4 of the present invention.

[0060] Figure 6 This is a cloud diagram of the conductivity of complex fractures.

[0061] Figure 7 This is a schematic diagram of the structure of a device for determining the conductivity of complex fractures in shale fracturing in Example 5 of the present invention.

[0062] Figure 8 This is a schematic diagram of the structure of an electronic device in Embodiment 9 of the present invention.

[0063] Reference numerals:

[0064] Figure 7 In: 701-prediction module, 702-numerical simulation module, 703-regional division module, 704-conductivity determination module;

[0065] Figure 8 In it: 800 - electronic device, 801 - processor, 802 - communication bus, 803 - user interface, 804 - communication interface, 805 - memory. DETAILED DESCRIPTION

[0066] The following will be combined with the accompanying drawings in 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, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the protection scope of the present invention.

[0067] As can be seen from the background technology, shale oil and gas reserves are abundant in my country, and shale oil and gas account for an important proportion of my country's annual new oil and gas reserves. However, the permeability of shale reservoirs is extremely low, and hydraulic fracturing technology must be used to transform the reservoirs to form a complex fracture system and provide shale oil and gas flow channels.

[0068] Fracture conductivity is one of the key parameters that determine the effect of hydraulic fracturing. Especially for deep shale reservoirs, natural fractures are relatively developed. After hydraulic fracturing, hydraulic fractures communicate with natural fractures, forming a complex fracture network in which the main fractures interact with secondary fractures and natural fractures. The migration ability of proppants in the main fractures, secondary fractures and natural fractures is different, which also causes the distribution pattern of proppants in the complex fracture system composed of main fractures, secondary fractures and natural fractures to be different. The distribution pattern of proppants in complex fractures determines the conductivity of fractures. The main fracture width is large, and proppants are easy to migrate and lay in it, thus forming a higher sand laying concentration and a larger laying range. The secondary fracture width is narrow, and the migration and laying ability of proppants in it is reduced, and the sand laying concentration and laying range become smaller. Natural fractures are at the end of the complex fracture system, and whether proppants can effectively enter the natural fractures and open them is a challenge. Some natural fractures and fractures that are not effectively supported by proppants will exist in a self-supporting form. The conductivity of such self-supporting fractures is much lower than the conductivity of effectively supported fractures. Especially under the high closure pressure of deep shale, the conductivity of self-supporting fractures will be greatly reduced. In addition, the high closure pressure of deep shale also affects the proppant in the effective support fracture, which is manifested in the embedding, crushing and creep of the proppant under high closure pressure. Therefore, the conductivity of complex fractures in deep shale is closely related to the distribution of complex fractures, the laying form of proppant in the fracture, and the embedding, crushing and creep of proppant under high closure pressure.

[0069] At present, the research on the conductivity of shale fractures has ignored the placement of proppants in the complex fracture morphology of shale. The conductivity test in a single main fracture is directly carried out using two parallel rock plates, or theoretical calculations are performed based on the parallel rock plate model. However, the placement of proppants is different under different fracture distributions, which leads to different conductivity of fractures of different orders in the complex fracture system of shale. The simple test results of parallel rock plates and model calculation results are obviously not able to replace the conductivity of the entire complex fracture system of shale.

[0070] Therefore, this application proposes a new method for determining the conductivity of complex fractures in shale fracturing to solve the above problems.

[0071] Embodiment 1

[0072] In the first embodiment of the present invention, a method for determining the conductivity of complex fractures in shale fracturing is provided. Figure 1 As shown, the method comprises the following steps:

[0073] Step S101: constructing a geological model and predicting the complex fracture distribution morphology of the target reservoir after hydraulic fracturing according to a preset fracturing construction strategy.

[0074] Step S102: establishing a proppant migration geometry model according to the complex fracture distribution morphology, and performing a proppant migration and paving numerical simulation operation according to the proppant migration geometry model under preset geological factors and preset engineering factors to obtain a numerical simulation result.

[0075] Step S103: According to the numerical simulation results, the complex fracture area is divided into an effective support fracture area and a self-support fracture area.

[0076] Step S104: According to a preset calculation model for effective supported fracture conductivity, a preset calculation model for self-supported fracture conductivity and numerical simulation results, respectively determine the fracture conductivity of the effective supported fracture area and the fracture conductivity of the self-supported fracture area.

[0077] Optionally, in step S101, constructing a geological model and predicting the complex fracture distribution morphology of a target reservoir after hydraulic fracturing according to a preset fracturing construction strategy specifically includes:

[0078] By means of numerical simulation, a geological model is established according to the physical and mechanical properties of the target reservoir, and then a hydraulic fracturing numerical simulation is performed according to the preset fracturing construction strategy, so as to predict the complex fracture distribution morphology of the target reservoir after hydraulic fracturing. The complex fracture distribution morphology can be found in Figure 2 .

[0079] It should be noted that the preset fracturing construction strategy is set by the technicians according to actual needs, and the present invention does not impose any special restrictions on this.

[0080] Specifically, existing software can be used to predict the complex fracture distribution morphology of the target reservoir after hydraulic fracturing. For example, software such as Gohfer and FracMan can be used to achieve this.

[0081] Optionally, in step S102, a proppant migration geometric model is established according to the complex fracture distribution morphology, specifically including:

[0082] According to the complex fracture distribution morphology, the computational fluid dynamics-discrete element coupling method was used to establish the proppant migration geometric model (proppant migration and placement numerical model).

[0083] In step S102, a proppant transport and placement numerical simulation operation is performed according to the proppant transport geometry model under preset geological factor conditions and preset engineering factor conditions, specifically including: based on the proppant transport geometry model, carrying out proppant transport and placement numerical simulation under preset engineering factors (sand-carrying fluid displacement, sand-carrying fluid viscosity, proppant type, proppant particle size and sand ratio) and preset geological factors (complex fracture morphology, fracture filtration loss and wall roughness), so as to obtain numerical simulation results.

[0084] The preset geological factors are determined according to the actual conditions of the complex fractures in the target reservoir. The preset engineering factors are set by the technicians according to actual needs, and the present invention does not impose any special restrictions on this.

[0085] Specifically, in step S102, existing numerical simulation software can be used to establish a proppant migration geometry model according to the complex fracture distribution morphology, and perform proppant migration and paving numerical simulation operations according to the proppant migration geometry model under preset geological factors and preset engineering factors. The present invention does not limit the specific numerical simulation software, and technicians can determine it according to actual needs.

[0086] More specifically, the numerical simulation results may include proppant placement morphology (see Figure 3 ), the position and quantity of proppant particles in complex fractures and other information can be further extracted from the proppant laying morphology, and then the proppant laying morphology, the position and quantity of proppant particles in complex fractures and other information can be used together as the numerical simulation results.

[0087] It should be noted that in step S102, when using numerical simulation software to establish a proppant migration geometric model based on the complex fracture distribution morphology, if the format of the complex fracture distribution morphology predicted by software such as Gohfer and FracMan in step S101 is different from the format required by the numerical simulation software, then before using the numerical simulation software to establish the proppant migration geometric model based on the complex fracture distribution morphology, it is necessary to use image recognition technology to identify and extract the complex fracture distribution morphology predicted in step S101 to obtain the complex fracture distribution morphology in the format required by the numerical simulation software.

[0088] Optionally, in step S103, according to the numerical simulation results, the complex fracture area is divided into an effective support fracture area and a self-support fracture area, specifically including:

[0089] According to the numerical simulation results, the position and quantity information of the proppant particles in the complex fractures are obtained, and then according to the position and quantity information of the proppant particles in the complex fractures, the complex fracture area is divided into an effective supported fracture area with proppant and a self-supported fracture area without proppant.

[0090] Optionally, there are multiple preset engineering factor conditions, wherein each preset engineering factor condition includes sand-carrying fluid displacement, sand-carrying fluid viscosity, proppant type, proppant particle size and sand ratio, and the specific values ​​of sand-carrying fluid displacement, sand-carrying fluid viscosity, proppant type, proppant particle size and sand ratio are different in different preset engineering factor conditions.

[0091] Furthermore, when there are multiple preset engineering factors:

[0092] The step S102 of performing the proppant migration and paving numerical simulation operation according to the proppant migration geometric model under the preset geological factor conditions and the preset engineering factor conditions includes:

[0093] According to the same preset geological factor condition, multiple proppant transport and paving numerical simulation operations are performed according to the proppant transport geometric model under different preset engineering factor conditions to obtain numerical simulation results under different preset engineering factor conditions (that is, one preset engineering factor condition corresponds to one proppant transport and paving numerical simulation operation, thereby obtaining numerical simulation results under each preset engineering factor condition);

[0094] Step S103 includes: dividing the complex crack area into effective supported crack areas and self-supported crack areas under different preset engineering factor conditions according to the numerical simulation results under different preset engineering factor conditions; that is, the effective supported crack areas include the effective supported crack areas under different preset engineering factor conditions, and the self-supported crack areas include the self-supported crack areas under different preset engineering factor conditions.

[0095] Step S104 includes: determining the fracture conductivity of the effective supported fracture zone and the fracture conductivity of the self-supported fracture zone under different preset engineering factor conditions respectively according to the preset effective supported fracture conductivity calculation model, the preset self-supported fracture conductivity calculation model and the numerical simulation results under different preset engineering factor conditions.

[0096] Optionally, before step S104, the method for determining the conductivity of complex fractures in shale fracturing further includes:

[0097] According to the information of target reservoir formation closure pressure and so on, and in accordance with the industry standard NB / T14023-2017 “Recommended method for determination of long-term conductivity of shale proppant filling layer”, long-term conductivity test of effective propped fractures and self-propping fractures under high closure pressure was carried out, and then the preset effective propped fracture conductivity calculation model and the preset self-propping fracture conductivity calculation model were fitted according to the test conditions and test results.

[0098] Among them, Figure 4 As shown, before step S104, a long-term conductivity test of effective supported fractures and self-supported fractures is carried out, and a preset effective supported fracture conductivity calculation model and a preset self-supported fracture conductivity calculation model are obtained by fitting according to the test conditions and test results. Specifically, the following steps are included:

[0099] Step S105: Taking the deep shale of the target reservoir as the test sample, a variety of effective support test conditions are preset.

[0100] Among them, the effective support test conditions include closing pressure conditions, pressure difference conditions, flow conditions, engineering factor conditions and the proppant transport and paving results corresponding to the engineering factor conditions. The engineering factor conditions and the proppant transport and paving results corresponding to the engineering factor conditions are determined according to the preset engineering factor conditions and numerical simulation results in the proppant transport and paving numerical simulation operation.

[0101] Among them, the closing pressure condition, the pressure difference condition, and the flow condition are set by the technicians according to actual needs, and the present invention does not impose any special restrictions on this.

[0102] The engineering factor conditions and the proppant transport and paving results corresponding to the engineering factor conditions are determined based on the preset engineering factor conditions and numerical simulation results in the proppant transport and paving numerical simulation operation; that is, the engineering factor conditions and the proppant transport and paving results corresponding to the engineering factor conditions adopt the preset engineering factor conditions and corresponding numerical simulation results in the proppant transport and paving numerical simulation operation.

[0103] Step S106: taking the closing pressure condition, the pressure difference condition and the flow condition in each effective support test condition as a self-support test condition to obtain a plurality of self-support test conditions.

[0104] That is, in the test of the conductivity of self-supporting fractures, the self-supporting test conditions adopt the closing pressure conditions, pressure difference conditions and flow conditions in the effective support test conditions for testing.

[0105] Step S107: performing effective support crack conductivity tests and self-support crack conductivity tests on the test samples under a variety of effective support test conditions and a variety of self-support test conditions, respectively, to obtain conductivity test results under each effective support test condition and conductivity test results under each self-support test condition.

[0106] It should be noted that when the test samples are tested for effective support fracture conductivity under a variety of effective support test conditions, the characteristics of proppant crushing, embedding, creep, etc. under high closure pressure should also be considered during the test process, so as to obtain the conductivity test results under each effective support test condition;

[0107] Before testing the conductivity of self-supporting fractures on test samples according to various self-supporting test conditions, the test samples need to be pre-processed in advance. The pre-processing includes first splitting the shale core of the test sample into two equal halves by artificial means, forming an irregular fracture wall on the splitting surface, and then displacing the two halves of the core by 1 to 2 mm to simulate the slippage of fractures in the formation. After pre-processing, different self-supporting test conditions can be applied for testing, thereby obtaining a series of self-supporting fracture long-term conductivity test data.

[0108] Step S108: establishing a preset effective support fracture conductivity calculation model and a preset self-support fracture conductivity calculation model according to each effective support test condition and its conductivity test result and each self-support test condition and its conductivity test result.

[0109] It can be understood that, in step S108, establishing a preset effective support fracture conductivity calculation model according to each effective support test condition and its conductivity test result includes: performing data fitting using each effective support test condition and its conductivity test result, thereby obtaining a preset effective support fracture conductivity calculation model;

[0110] A self-supporting fracture conductivity calculation model is preset according to each self-supporting test condition and its conductivity test result, including: using each self-supporting test condition and its conductivity test result to perform data fitting, so as to obtain the preset self-supporting fracture conductivity calculation model.

[0111] The method for determining the conductivity of complex fractures in shale fracturing provided by an embodiment of the present invention, when determining the conductivity of complex fractures, first predicts the complex fracture distribution morphology of the target reservoir after hydraulic fracturing, and performs numerical simulation of proppant migration and laying according to the complex fracture distribution morphology, thereby dividing the complex fracture area into an effective support fracture area and a self-supporting fracture area according to the numerical simulation results, and respectively using a preset effective support fracture conductivity calculation model and a preset self-supporting fracture conductivity calculation model to calculate the conductivity of the effective support fracture area and the self-supporting fracture area, and the entire determination process comprehensively considers the complex fracture distribution morphology and the proppant laying morphology, so that the conductivity of the entire deep shale complex fracture system can be obtained more accurately.

[0112] Embodiment 2

[0113] On the basis of the first embodiment, the second embodiment provides a specific implementation method of step S104 in the first embodiment. In the second embodiment, step S104 specifically includes the following steps:

[0114] Step S1041: Divide the complex crack area into a plurality of grid units of preset sizes.

[0115] Specifically, the complex crack area can be divided into i×j grid units, and the preset size of each grid unit is dx×dy.

[0116] Step S1042: Determine the fracture conductivity of each grid unit in the effective support fracture area according to the preset effective support fracture conductivity calculation model and numerical simulation results.

[0117] Step S1043: Determine the fracture conductivity of each grid unit in the self-supporting fracture area according to the preset self-supporting fracture conductivity calculation model and numerical simulation results.

[0118] Among them, the numerical simulation results include the number and position of proppant particles. The grid cells with the number of proppant particles greater than the preset number threshold are regarded as grid cells in the effective supported fracture zone, and the grid cells with the number of proppant particles not greater than the preset number threshold are regarded as grid cells in the self-supported fracture zone.

[0119] The preset quantity threshold can be set by the technician according to actual needs, and the present invention does not limit the characteristics of this. Preferably, the preset quantity threshold can be set to 0.

[0120] It can be understood that when there are multiple preset engineering factor conditions, since effective supported fracture zones and self-supported fracture zones under different preset engineering factor conditions can be obtained, in step S1042 and step S1043, it is necessary to determine the fracture conductivity of each grid unit in the effective supported fracture zone under each preset engineering factor condition and the fracture conductivity of each grid unit in the self-supported fracture zone under each preset engineering factor condition.

[0121] The method for determining the conductivity of complex fractures in shale fracturing provided in this embodiment, when determining the fracture conductivity of the effective support fracture area and the fracture conductivity of the self-support fracture area respectively according to a preset effective support fracture conductivity calculation model, a preset self-support fracture conductivity calculation model and numerical simulation results, based on the idea of ​​difference, the complex fracture area is divided into multiple grid units of preset sizes, and then the preset effective support fracture conductivity calculation model is used to determine the conductivity of each grid unit in the effective support fracture area, and the self-support fracture conductivity calculation model is used to determine the conductivity of each grid unit in the self-support fracture area. When the number of grid units is large enough, according to the idea of ​​difference, it can be considered that the fracture conductivity of each grid unit can reflect the fracture conductivity under the corresponding proppant laying conditions at its location, thereby obtaining the conductivity of the entire deep shale complex fracture system.

[0122] Embodiment 3

[0123] In the third embodiment of the present invention, the preset effective support fracture conductivity calculation model in step S104 may include:

[0124]

[0125] Among them, F RCD is the effective supporting fracture conductivity, the unit is D·cm;

[0126] c0 is the correction coefficient;

[0127] D is the fracture opening when the fracture is closed and pressurized onto the proppant when the closing pressure is 0, in mm;

[0128] α(t) is the deformation of the fracture width due to proppant creep over time, in mm;

[0129] φ(t) is the change of porosity with time due to proppant creep, dimensionless;

[0130] r(t) is the deformation of the pore due to proppant creep over time, in mm;

[0131] τ(t) is the time-varying variable of tortuosity, dimensionless;

[0132] K1, K2, K3 and K4 are all constants, among which K1 can be 2, K2 can be 2, K3 can be 8, and K4 can be 2.

[0133] Specifically, c0 is used to correct the conductivity result (theoretical calculation result) calculated by the model so that the conductivity result is close to the experimental measurement result (conductivity test result). The specific value of c0 is determined according to the theoretical calculation result and the experimental measurement result, and the present invention does not specifically limit this.

[0134] It should be noted that α(t), φ(t), r(t) and τ(t) are obtained by data fitting using each effective support test condition and its flow conductivity test result, and the present invention does not impose any special restrictions on this.

[0135] Among them, α(t), φ(t), r(t), and τ(t) are functions related to the sand concentration. Therefore, when determining the conductivity using the effective support fracture conductivity calculation model, it is necessary to first determine the sand concentration based on the numerical fitting result in step S102.

[0136] Furthermore, when a complex fracture area is divided into multiple grid units of preset sizes, the sand concentration of each grid unit can be determined according to the preset size of the grid unit and the number of proppant particles, and then the conductivity of each grid unit in the effective support fracture area can be determined according to the preset effective support fracture conductivity calculation model.

[0137] In step S104, the preset self-supporting fracture conductivity calculation model may include:

[0138]

[0139] Among them, F CD is the conductivity of the self-supporting fracture, in D·cm;

[0140] Q is the volume flow rate of the sand-carrying fluid, in cm 3 / s;

[0141] δ is the ratio of crack length to height, dimensionless;

[0142] P0, P1, and P2 are atmospheric pressure, fracture inlet pressure, and fracture outlet pressure, respectively, in atm;

[0143] K5, K6 and K7 are all constants. Preferably, the values ​​of K5, K6 and K7 are all 2.

[0144] Specifically, when a complex fracture area is divided into multiple grid units of preset sizes, the volume flow rate of sand-carrying fluid, the ratio of fracture length to height, the fracture inlet pressure, and the fracture outlet pressure of each grid unit in the self-supporting fracture area can be obtained respectively, and the conductivity of each grid unit in the self-supporting fracture area can be determined using the preset self-supporting fracture conductivity calculation model.

[0145] Embodiment 4

[0146] A method for determining a shale fracturing complex fracture conductivity cloud map is provided in a fourth embodiment of the present invention. Figure 5 As shown, the method includes:

[0147] Step S501: Determine the complex fracture conductivity of the target reservoir according to the method for determining the complex fracture conductivity of shale fracturing.

[0148] Among them, the complex fracture conductivity includes the fracture conductivity of the effective support fracture zone and the fracture conductivity of the self-support fracture zone, and the method for determining the complex fracture conductivity of shale fracturing is the method for determining the complex fracture conductivity of shale fracturing provided in the above embodiment.

[0149] Step S502: determining a complex fracture conductivity cloud map according to the complex fracture conductivity.

[0150] Specifically, after the fracture conductivity of the effective supported fracture zone and the fracture conductivity of the self-supported fracture zone are determined, the complex fracture conductivity cloud map can be determined according to the position and fracture conductivity of the effective supported fracture zone and the position and fracture conductivity of the self-supported fracture zone.

[0151] Furthermore, when the complex fracture area is divided into a plurality of grid units of preset sizes, after the fracture conductivity of each grid unit in the effective supported fracture area is determined according to the preset effective supported fracture conductivity calculation model, and the fracture conductivity of each grid unit in the self-supported fracture area is determined according to the preset self-supported fracture conductivity calculation model, the complex fracture conductivity cloud map can be determined according to the fracture conductivity and position of each grid unit.

[0152] For example, the conductivity cloud diagram of complex fractures can be found in Figure 6 .

[0153] Embodiment 5

[0154] This embodiment 5 provides a device for determining the conductivity of complex fractures in shale fracturing, such as Figure 7 As shown, the device comprises:

[0155] The prediction module 701 is used to construct a geological model and predict the complex fracture distribution morphology of the target reservoir after hydraulic fracturing according to a preset fracturing construction strategy.

[0156] The numerical simulation module 702 is used to establish a proppant migration geometry model according to the complex fracture distribution morphology, and perform a proppant migration and paving numerical simulation operation according to the proppant migration geometry model under preset geological factors and preset engineering factors to obtain a numerical simulation result;

[0157] A region division module 703 is used to divide the complex fracture region into an effective support fracture region and a self-support fracture region according to the numerical simulation results;

[0158] The conductivity determination module 704 is used to determine the fracture conductivity of the effective supported fracture area and the fracture conductivity of the self-supported fracture area respectively according to the preset effective supported fracture conductivity calculation model, the preset self-supported fracture conductivity calculation model and the numerical simulation results.

[0159] Optionally, there are multiple preset engineering factor conditions; under the preset geological factor conditions and the preset engineering factor conditions, the proppant migration and paving numerical simulation operation is performed according to the proppant migration geometric model, including:

[0160] According to the same preset geological factor condition, multiple proppant migration and laying numerical simulation operations are performed according to the proppant migration geometric model under different preset engineering factor conditions to obtain numerical simulation results under different preset engineering factor conditions;

[0161] The effective support crack area includes: the effective support crack area under different preset engineering factors;

[0162] The self-supporting crack zone includes: the self-supporting crack zone under different preset engineering factor conditions.

[0163] Optionally, the device also includes a model building module, which is used to take the deep shale of the target reservoir as a test sample and preset a plurality of effective support test conditions; wherein the effective support test conditions include closing pressure conditions, pressure difference conditions, flow conditions, engineering factor conditions and proppant migration and laying results corresponding to the engineering factor conditions, and the engineering factor conditions and the proppant migration and laying results corresponding to the engineering factor conditions are determined according to the preset engineering factor conditions and numerical simulation results in the proppant migration and laying numerical simulation operation; the closing pressure conditions, pressure difference conditions and flow conditions in each effective support test condition are used as self-support test conditions to obtain a plurality of self-support test conditions; under a plurality of effective support test conditions and a plurality of self-support test conditions, effective support fracture conductivity tests and self-support fracture conductivity tests are performed on the test samples respectively, so as to obtain the conductivity test results under each effective support test condition and the conductivity test results under each self-support test condition; according to each effective support test condition and its conductivity test results and each self-support test condition and its conductivity test results, a preset effective support fracture conductivity calculation model and a preset self-support fracture conductivity calculation model are established.

[0164] Optionally, the flow conductivity determination module 704 includes:

[0165] A grid unit division unit, used to divide a complex crack region into a plurality of grid units of preset sizes;

[0166] A conductivity determination unit is used to determine the fracture conductivity of each grid unit in the effective support fracture area according to a preset effective support fracture conductivity calculation model and numerical simulation results; and is also used to determine the fracture conductivity of each grid unit in the self-support fracture area according to a preset self-support fracture conductivity calculation model and numerical simulation results;

[0167] Among them, the numerical simulation results include the number and position of proppant particles. The grid cells with the number of proppant particles greater than the preset number threshold are regarded as grid cells in the effective supported fracture zone, and the grid cells with the number of proppant particles not greater than the preset number threshold are regarded as grid cells in the self-supported fracture zone.

[0168] Optionally, the preset effective support fracture conductivity calculation model includes:

[0169]

[0170] Among them, F RCD To effectively support the fracture conductivity;

[0171] c0 is the correction coefficient;

[0172] D is the fracture opening when the fracture is closed and pressurized onto the proppant when the closing pressure is 0;

[0173] α(t) is the deformation of the fracture width over time due to proppant creep;

[0174] φ(t) is the variation of porosity with time due to proppant creep;

[0175] r(t) is the deformation of the pore due to proppant creep over time;

[0176] τ(t) is the variation of tortuosity over time;

[0177] K1, K2, K3 and K4 are all constants.

[0178] Optionally, the preset self-supporting fracture conductivity calculation model includes:

[0179]

[0180] Among them, F CD is the conductivity of the self-supporting fracture;

[0181] Q is the volume flow rate of sand-carrying fluid;

[0182] δ is the ratio of crack length to height;

[0183] P0, P1, and P2 are atmospheric pressure, fracture inlet pressure, and fracture outlet pressure, respectively;

[0184] K5, K6 and K7 are all constants.

[0185] The device for determining the conductivity of complex fractures in shale fracturing provided in this embodiment, when determining the conductivity of complex fractures, first predicts the distribution morphology of complex fractures in the target reservoir after hydraulic fracturing, and performs numerical simulation of proppant migration and laying according to the distribution morphology of complex fractures, thereby dividing the complex fracture area into an effective support fracture area and a self-support fracture area according to the numerical simulation results, and respectively using a preset effective support fracture conductivity calculation model and a preset self-support fracture conductivity calculation model for the effective support fracture area and the self-support fracture area to calculate the conductivity, and the entire determination process comprehensively considers the complex fracture distribution morphology and the proppant laying morphology, so that the conductivity of the entire deep shale complex fracture system can be obtained more accurately.

[0186] Embodiment 6

[0187] This embodiment provides a specific example of applying the above-mentioned method for determining the conductivity of complex fractures in shale fracturing to determine the conductivity of complex fractures in a target reservoir.

[0188] This example uses a certain fracturing block as an example to calculate the conductivity of complex fractures. The specific steps are as follows:

[0189] Step 1: predict the distribution morphology of complex fractures in deep shale pressure in the target reservoir after hydraulic fracturing.

[0190] Through numerical simulation, a geological model is constructed according to the physical and mechanical properties of the target reservoir, and then a hydraulic fracturing numerical simulation is performed according to the predetermined fracturing construction plan to predict the complex fracture expansion path and fracture distribution morphology of the target reservoir after hydraulic fracturing. Then, image recognition technology is used to extract the complex fracture distribution morphology formed after shale fracturing.

[0191] Step 2: Numerical simulation and regional division of proppant migration and placement in complex fractures

[0192] According to the distribution morphology of complex fractures in deep shale fracturing predicted in step 1, the numerical model of proppant migration and placement (proppant migration geometry model) is established by using the computational fluid dynamics-discrete element coupling method. Based on the above model, numerical simulations of proppant migration and placement under different engineering factors (sand-carrying fluid displacement, sand-carrying fluid viscosity, proppant type, proppant particle size, sand ratio) and geological factors (complex fracture morphology, fracture filtration, wall roughness) are carried out.

[0193] According to the numerical simulation results, by extracting the position, quantity and other information of proppant particles in complex fractures, the complex fracture area is divided into an effective supported fracture area with proppant and a self-supported fracture area without proppant.

[0194] When the proppant with a diameter of 0.8 mm, elastic modulus of 1836 MPa, Poisson's ratio of 0.2 and viscous modulus of 15000 MPa is selected, the proppant with a diameter of 4.8 mm 3 When the sand-carrying fluid with a viscosity of 1 mPa·s is injected at a displacement of 1 / min, the proppant migration and laying morphology in complex fractures can be seen in Figure 3 , where the fracture area with proppant is the effective supported fracture area, and the fracture area without proppant is the self-supported fracture area.

[0195] Step 3: Conduct fracture conductivity testing

[0196] Taking the deep shale of the target reservoir as the test sample, according to the information such as the closure pressure of the target reservoir formation, and in accordance with the industry standard NB / T14023-2017 "Recommended method for determining the long-term conductivity of shale proppant filling layers", the long-term conductivity test of effective propped fractures and self-propped fractures under high closure pressure was carried out.

[0197] The effective support test conditions for the long-term conductivity test of effective proppant fractures are carried out in combination with the proppant type, particle size and the simulated proppant quantity in the fracture (i.e., sand concentration) in step 2. The test process takes into account the characteristics of proppant breakage, embedding, creep, etc. under high closure pressure, and obtains a series of conductivity test data under different effective support test conditions.

[0198] Among them, each effective support test condition includes a closing pressure condition, a pressure difference condition, a flow condition, an engineering factor condition, and a proppant migration and paving result corresponding to the engineering factor condition. The engineering factor condition and the proppant migration and paving result corresponding to the engineering factor condition are determined according to the preset engineering factor condition in step 2 and its corresponding numerical simulation result.

[0199] In the test of the conductivity of self-supporting fractures, the shale core is first split into two equal halves by artificial means, and the split surface forms an irregular fracture wall. Then the two halves of the core are displaced by 1 to 2 mm to simulate the slip of fractures in the formation. The closing pressure condition, pressure difference condition, and flow condition in each effective support test condition are used as each self-support test condition for the long-term conductivity test of self-supporting fractures, and long-term conductivity tests under different self-supporting test conditions are carried out, and a series of conductivity test data under different self-supporting test conditions are obtained.

[0200] Step 4: Establish a calculation model for the conductivity of effective supported fractures and a calculation model for the conductivity of self-supported fractures.

[0201] Based on the long-term conductivity data of effective supported fractures and self-supported fractures under high closure pressure measured in step 3, a calculation model for the conductivity of effective supported fractures and a calculation model for the conductivity of self-supported fractures are established.

[0202] The conductivity calculation model of effective support fracture conductivity includes:

[0203]

[0204] Among them, F RCD is the effective supporting fracture conductivity, the unit is D·cm;

[0205] c0 is the correction coefficient;

[0206] D is the fracture opening when the fracture is closed and pressurized onto the proppant when the closing pressure is 0, in mm;

[0207] α(t) is the deformation of the fracture width due to proppant creep over time, in mm;

[0208] φ(t) is the change of porosity with time due to proppant creep, dimensionless;

[0209] r(t) is the deformation of the pore due to proppant creep over time, in mm;

[0210] τ(t) is the time-varying variable of tortuosity, dimensionless;

[0211] K1, K2, K3 and K4 are all constants, among which K1 can be 2, K2 can be 2, K3 can be 8, and K4 can be 2.

[0212] The calculation model of self-supporting fracture conductivity includes:

[0213]

[0214] Among them, F CD is the conductivity of the self-supporting fracture, in D·cm;

[0215] Q is the volume flow rate of the sand-carrying fluid, in cm 3 / s;

[0216] δ is the ratio of crack length to height, dimensionless;

[0217] P0, P1, and P2 are atmospheric pressure, fracture inlet pressure, and fracture outlet pressure, respectively, in atm;

[0218] K5, K6 and K7 are all constants. Preferably, the values ​​of K5, K6 and K7 are all 2.

[0219] Step 5: Calculation of complex fracture conductivity and drawing of conductivity cloud map

[0220] Based on steps 3 and 4, the effective support fracture and self-support fracture conductivity models established through the conductivity test results can be obtained. The present invention is based on the differential concept. By dividing the complex fracture area into i×j grids, the size of each grid unit is dx×dy, and the number of proppant particles falling into each grid is counted, recorded as Nij, and further, the sand concentration of each grid unit can be determined according to the size of the grid unit and the number of proppant particles. The fracture conductivity at each grid unit can be determined according to the fracture conductivity calculation model established in step 4. In this way, the entire complex fracture can be differentiated into a number of grid units whose conductivity can be calculated. When the number of grids is large enough, according to the differential concept, it can be considered that the fracture conductivity of each grid unit can reflect the fracture conductivity under the corresponding proppant laying conditions at its location. All grid units with calculated fracture conductivity are summarized and reconstructed according to the position information to form a cloud map of the conductivity of the entire complex fracture.

[0221] Embodiment 7

[0222] This embodiment provides a computer program product, which includes a computer program or instructions. When the computer program or instructions are executed by a processor, all or part of the steps of the method for determining the conductivity of complex fractures in shale fracturing as described in the above embodiment are implemented.

[0223] Among them, the methods for determining the conductivity of complex fractures in shale fracturing include:

[0224] Construct a geological model and predict the complex fracture distribution of the target reservoir after hydraulic fracturing based on the preset fracturing construction strategy;

[0225] Establish a proppant migration geometry model according to the complex fracture distribution morphology, and perform proppant migration and paving numerical simulation operations according to the proppant migration geometry model under preset geological factors and preset engineering factors to obtain numerical simulation results;

[0226] According to the numerical simulation results, the complex fracture area is divided into effective support fracture area and self-support fracture area;

[0227] According to the preset calculation model of effective supported fracture conductivity, the preset calculation model of self-supported fracture conductivity and the numerical simulation results, the fracture conductivity of the effective supported fracture zone and the fracture conductivity of the self-supported fracture zone are determined respectively.

[0228] Further, the computer program product may include one or more computer executable components configured to execute the embodiment when the program is run; the computer program product may also include a computer program tangibly contained on a readable medium, the computer program including program code for executing any method in the embodiments of the present disclosure. In such an embodiment, the computer program can be downloaded and installed from a network through a communication part, and / or installed from a removable medium.

[0229] Embodiment 8

[0230] This embodiment provides a computer-readable storage medium. The computer-readable storage medium stores a computer program, which, when executed by one or more processors, implements all or part of the steps of the method for determining the conductivity of complex fractures in shale fracturing in the above embodiment.

[0231] Among them, the methods for determining the conductivity of complex fractures in shale fracturing include:

[0232] Construct a geological model and predict the complex fracture distribution of the target reservoir after hydraulic fracturing based on the preset fracturing construction strategy;

[0233] Establish a proppant migration geometry model according to the complex fracture distribution morphology, and perform proppant migration and paving numerical simulation operations according to the proppant migration geometry model under preset geological factors and preset engineering factors to obtain numerical simulation results;

[0234] According to the numerical simulation results, the complex fracture area is divided into effective support fracture area and self-support fracture area;

[0235] According to the preset calculation model of effective supported fracture conductivity, the preset calculation model of self-supported fracture conductivity and the numerical simulation results, the fracture conductivity of the effective supported fracture zone and the fracture conductivity of the self-supported fracture zone are determined respectively.

[0236] Embodiment 9

[0237] This embodiment provides an electronic device, Figure 8 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application is shown in FIG. Figure 8 As shown, the electronic device 800 includes: at least one processor 801, at least one communication bus 802, a user interface 803, at least one external communication interface 804, and a memory 805. The communication bus 802 is configured to realize the connection and communication between these components. The user interface 803 may include a display screen, and the external communication interface 804 may include a standard wired interface and a wireless interface. A computer program is stored in the memory 805, and the memory 805 and one or more processors 801 are connected to each other in communication. When the computer program is executed by one or more processors, the processor 801 is configured to execute the computer program stored in the memory to implement all or part of the steps of the method for determining the conductivity of complex fractures in shale fracturing in the above-mentioned embodiment, which will not be repeated in this embodiment.

[0238] The method, device and electronic equipment for determining the conductivity of complex fractures in shale fracturing provided by the present invention, when determining the conductivity of complex fractures, first predict the complex fracture distribution morphology of the target reservoir after hydraulic fracturing, and perform numerical simulation of proppant migration and laying according to the complex fracture distribution morphology, so as to divide the complex fracture area into an effective support fracture area and a self-support fracture area according to the numerical simulation results, and respectively use a preset effective support fracture conductivity calculation model and a preset self-support fracture conductivity calculation model to calculate the conductivity of the effective support fracture area and the self-support fracture area, and the entire determination process comprehensively considers the complex fracture distribution morphology and the proppant laying morphology, so that the conductivity of the entire deep shale complex fracture system can be obtained more accurately.

[0239] The terms and expressions used in the present specification are for illustration only and are not intended to be limiting. It should be understood by those skilled in the art that various changes may be made to the details of the above embodiments without departing from the basic principles of the disclosed embodiments. Therefore, the scope of the present invention is determined solely by the claims, and in the claims, unless otherwise indicated, all terms should be understood in the broadest reasonable sense.

Claims

1. A method for determining the conductivity of complex fractures in shale fracturing, characterized in that: The method comprises: Construct a geological model and predict the complex fracture distribution of the target reservoir after hydraulic fracturing based on the preset fracturing construction strategy; Establishing a proppant migration geometry model according to the complex fracture distribution morphology, and performing a proppant migration and paving numerical simulation operation according to the proppant migration geometry model under preset geological factors and preset engineering factors to obtain a numerical simulation result; According to the numerical simulation results, the complex fracture area is divided into an effective support fracture area and a self-support fracture area; According to the preset effective supported fracture conductivity calculation model, the preset self-supported fracture conductivity calculation model and the numerical simulation results, the fracture conductivity of the effective supported fracture zone and the fracture conductivity of the self-supported fracture zone are determined respectively.

2. The method for determining the conductivity of complex fractures in shale fracturing according to claim 1, characterized in that: There are multiple preset engineering factors and conditions; The method of performing the proppant migration and paving numerical simulation operation according to the proppant migration geometric model under the preset geological factor conditions and the preset engineering factor conditions includes: According to the same preset geological factor condition, multiple proppant migration and paving numerical simulation operations are performed according to the proppant migration geometric model under different preset engineering factor conditions to obtain numerical simulation results under different preset engineering factor conditions; The effective supporting fracture area includes: an effective supporting fracture area under different preset engineering factors; The self-supporting fracture zone includes: a self-supporting fracture zone under different preset engineering factor conditions.

3. The method for determining the conductivity of complex fractures in shale fracturing according to claim 2, characterized in that: The method further comprises: Taking the deep shale of the target reservoir as a test sample, a plurality of effective support test conditions are preset; wherein the effective support test conditions include closure pressure conditions, pressure difference conditions, flow conditions, engineering factor conditions, and proppant migration and paving results corresponding to the engineering factor conditions, and the engineering factor conditions and the proppant migration and paving results corresponding to the engineering factor conditions are determined according to the preset engineering factor conditions and numerical simulation results in the proppant migration and paving numerical simulation operation; The closing pressure condition, the pressure difference condition and the flow condition in each effective support test condition are used as self-support test conditions to obtain a variety of self-support test conditions; Conducting effective support fracture conductivity tests and self-support fracture conductivity tests on the test samples under a variety of effective support test conditions and a variety of self-support test conditions, respectively, to obtain conductivity test results under each effective support test condition and each self-support test condition; The preset effective support fracture conductivity calculation model and the preset self-support fracture conductivity calculation model are established according to each effective support test condition and its conductivity test result and each self-support test condition and its conductivity test result.

4. The method for determining the conductivity of complex fractures in shale fracturing according to claim 1, characterized in that: The method of determining the fracture conductivity of the effective supported fracture zone and the fracture conductivity of the self-supported fracture zone respectively according to the preset effective supported fracture conductivity calculation model, the preset self-supported fracture conductivity calculation model and the numerical simulation result comprises: Dividing the complex crack region into a plurality of grid units of preset sizes; Determining the fracture conductivity of each grid unit in the effective support fracture area according to the preset effective support fracture conductivity calculation model and the numerical simulation result; Determining the fracture conductivity of each grid unit in the self-supporting fracture zone according to the preset self-supporting fracture conductivity calculation model and the numerical simulation result; The numerical simulation results include the number and position of proppant particles, and the grid cells with a number of proppant particles greater than a preset number threshold are regarded as grid cells in the effective supported fracture zone, and the grid cells with a number of proppant particles not greater than the preset number threshold are regarded as grid cells in the self-supported fracture zone.

5. The method for determining the conductivity of complex fractures in shale fracturing according to claim 1, characterized in that: The preset effective support fracture conductivity calculation model includes: Among them, R RCD To effectively support the fracture conductivity; c0 is the correction coefficient; D is the fracture opening when the fracture is closed and pressurized onto the proppant when the closing pressure is 0; α(t) is the deformation of the fracture width over time due to proppant creep; φ(t) is the variation of porosity with time due to proppant creep; r(t) is the deformation of the pore due to proppant creep over time; τ(t) is the variation of tortuosity over time; K1, K2, K3 and K4 are all constants.

6. The method for determining the conductivity of complex fractures in shale fracturing according to claim 1, characterized in that: The preset self-supporting fracture conductivity calculation model includes: Among them, F CD is the conductivity of the self-supporting fracture; Q is the volume flow rate of sand-carrying fluid; δ is the ratio of crack length to height; P0, P1, and P2 are atmospheric pressure, fracture inlet pressure, and fracture outlet pressure, respectively; K5, K6 and K7 are all constants.

7. A method for determining the conductivity cloud map of complex fractures in shale fracturing, characterized in that: The method comprises: The complex fracture conductivity of the target reservoir is determined according to the method for determining the complex fracture conductivity of shale fracturing according to any one of claims 1 to 6; wherein the complex fracture conductivity includes the fracture conductivity of the effective supporting fracture zone and the fracture conductivity of the self-supporting fracture zone; A complex fracture conductivity cloud map is determined according to the complex fracture conductivity.

8. A device for determining the conductivity of complex fractures in shale fracturing, characterized in that: The device comprises: The prediction module is used to construct a geological model and predict the complex fracture distribution of the target reservoir after hydraulic fracturing according to the preset fracturing construction strategy; A numerical simulation module is used to establish a proppant migration geometry model according to the complex fracture distribution morphology, and perform a proppant migration and paving numerical simulation operation according to the proppant migration geometry model under preset geological factors and preset engineering factors to obtain a numerical simulation result; A region division module, used for dividing the complex fracture region into an effective support fracture region and a self-support fracture region according to the numerical simulation results; The conductivity determination module is used to determine the fracture conductivity of the effective supported fracture zone and the fracture conductivity of the self-supported fracture zone respectively according to a preset effective supported fracture conductivity calculation model, a preset self-supported fracture conductivity calculation model and the numerical simulation results.

9. A computer-readable storage medium, characterized in that: The computer program stored in the computer-readable storage medium, when executed by one or more processors, implements the steps of the method according to any one of claims 1 to 7.

10. An electronic device, characterized in that: The method comprises a memory and one or more processors, wherein a computer program is stored in the memory, and when the computer program is executed by the one or more processors, the steps of the method according to any one of claims 1 to 7 are performed.

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