Reservoir matrix fracturing fluid filter loss calculation method and device and computer equipment

Abstract

The embodiment of the invention provides a reservoir matrix fracturing fluid filter loss calculation method and device and computer equipment, and relates to the technical field of oil exploitation, and the method comprises the following steps: obtaining pressure data of each pressure measuring point of a rock core in a reservoir rock core fracturing fluid damage experiment process; determining the fracturing fluid damage length of the reservoir core according to the pressure data; according to the damage length of the fracturing fluid, parameters of reservoir matrix fracturing fluid permeability changing along with invasion depth are calculated; calculating the reservoir fracturing fluid filtration depth according to the fracturing fluid density, the fracturing fluid viscosity and the reservoir matrix fracturing fluid permeability change parameters along with the invasion depth; and according to the average fracture height and fracture length of the hydraulic main fracture, the average fracture height and fracture length of the branch fractures and the reservoir fracturing fluid filtration depth, calculating the total filtration loss of the fracturing fluid. According to the method, the influence of factors such as the change of the permeability of the reservoir matrix fracturing fluid along with the invasion depth, the density of the fracturing fluid and the viscosity of the fracturing fluid can be considered, and the filter loss of the reservoir matrix fracturing fluid can be quickly and accurately calculated.

Description

Technical Field

[0001] The embodiments of this specification relate to the field of oil production technology, and in particular to a method, device and computer equipment for calculating the fluid loss of reservoir matrix fracturing fluid. Background Art

[0002] During the hydraulic fracturing of reservoirs, the filtration loss of fracturing fluid is one of the important parameters for evaluating the efficiency of fracturing fluid and the scale of fracture creation. First, the filtration loss of fracturing fluid will cause the change of the effective fracturing fluid volume in the hydraulic fracture, that is, the effective fracturing fluid volume is the difference between the volume of pumped fracturing fluid and the filtration loss volume of fracturing fluid. The ratio of the volume of fracturing fluid in the fracture to the volume of pumped fracturing fluid can be defined as the efficiency of fracturing fluid. The greater the efficiency of fracturing fluid in the fracture, the higher the fracture creation efficiency. Therefore, the effective evaluation of the filtration loss of fracturing fluid is helpful for the fine design of the fracturing fluid volume, so as to design a reasonable construction fracturing fluid volume, thereby achieving the target transformation volume of reservoir fractures. Secondly, the filtration loss of fracturing fluid causes the change of fluid pressure in the fracture. Under the same pumping displacement, the greater the filtration loss of fracturing fluid, the smaller the fluid pressure in the fracture; at this time, the width of the hydraulic fracture is smaller, which is easy to increase the resistance to proppant migration; finally, the conductivity of the fracturing fracture will not meet the requirements for efficient production of reservoir oil and gas. For reservoirs, the fluid loss of fracturing fluid is mainly affected by factors such as rock matrix permeability, porosity, and fracture pressure. In the prior art, there is a lack of calculation methods for the fluid loss of reservoir fracturing fluid.

[0003] In view of this, the embodiments of this specification are intended to provide a method, device and computer equipment for calculating the fluid loss of reservoir matrix fracturing fluid. Summary of the invention

[0004] In view of the above problems in the prior art, the purpose of the embodiments of this specification is to provide a method, device and computer equipment for calculating the fluid loss of reservoir matrix fracturing fluid, so as to solve the problem that there is a lack of a method for calculating the fluid loss of fracturing fluid in the prior art.

[0005] In a first aspect, an embodiment of this specification provides a method for calculating the fluid loss of a reservoir matrix fracturing fluid, comprising:

[0006] Obtain the pressure data of each pressure measuring point in the core during the reservoir core fracturing fluid damage experiment;

[0007] Determining the fracturing fluid damage length of the reservoir core according to the pressure data;

[0008] Calculating the parameter of reservoir matrix fracturing fluid permeability varying with invasion depth according to the fracturing fluid damage length;

[0009] According to the density of the fracturing fluid, the viscosity of the fracturing fluid and the parameters of the change of the permeability of the reservoir matrix fracturing fluid with the invasion depth, the reservoir fracturing fluid loss depth is calculated, and the reservoir fracturing fluid loss depth is:

[0010]

[0011] Among them, D loss is the fracturing fluid loss depth, cm; ρ fluid is the density of fracturing fluid, g / cm 3 ; K m (i) is the permeability at the invasion depth i after the fracturing fluid invasion damage, 10 -3 μm 2 ; i is the penetration depth, cm; P fracture is the fluid pressure in the crack, MPa; P formation is the reservoir pore pressure, MPa; μ fluid is the fracturing fluid viscosity, mPa.s; K rock is the reservoir matrix permeability, 10 -3 μm 2 ; a, b are the reservoir matrix porosity-permeability regression coefficients, dimensionless;

[0012] The total fluid loss of the fracturing fluid is calculated based on the average fracture height and fracture length of the hydraulic main fracture, the average fracture height and fracture length of the branch fractures, and the fluid loss depth of the reservoir fracturing fluid.

[0013] Specifically, determining the fracturing fluid damage length of the reservoir core according to the pressure data further includes:

[0014] Obtain the pressure data of each pressure measuring point on the core holder under the conditions of initial inlet pressure, initial outlet pressure and preset fracturing time in the fracturing fluid damage experiment;

[0015] Calculate the pressure gradient difference coefficient of each pressure measuring point according to the pressure data of each pressure measuring point, the initial inlet end pressure and the initial outlet end pressure;

[0016] Determine whether there is a pressure measuring point among the pressure measuring points whose pressure gradient difference coefficient meets a preset condition;

[0017] When there is a prediction point where the pressure gradient difference coefficient meets the preset condition, the fracturing fluid damage length is determined according to the pressure measuring point where the pressure gradient difference coefficient meets the preset condition and the number of repetitions of the fracturing fluid damage experiment;

[0018] When all the pressure measuring points do not meet the preset conditions, the initial inlet pressure is updated and the fracturing fluid damage experiment is repeated at the preset fracturing time until there is a predicted point where the pressure gradient difference coefficient meets the preset conditions.

[0019] Specifically, the pressure gradient difference coefficient is calculated according to the following formula:

[0020] η j =(GPj -G rock ) / G rock

[0021] Among them, η j is the pressure gradient difference coefficient of the jth pressure measuring point, dimensionless; G Pj is the pressure gradient corresponding to the jth pressure measuring point, MPa / cm; G rock is the pressure gradient between the outlet and inlet of the core holder, MPa / cm;

[0022]

[0023]

[0024] Among them, P j is the pressure at the jth pressure measuring point, MPa; P j-1 is the pressure at the j-1th pressure measuring point, MPa; ΔL is the core length between two adjacent pressure measuring points, cm; P in is the pressure at the inlet of the core holder, MPa; P out is the pressure at the outlet of the core holder, MPa; L is the length of the reservoir core, cm.

[0025] Further, when there is a prediction point where the pressure gradient difference coefficient meets the preset conditions, the fracturing fluid damage length is determined according to the pressure measuring point where the pressure gradient difference coefficient meets the preset conditions and the number of repetitions of the fracturing fluid damage experiment:

[0026] L damage =nL+jΔL

[0027] Among them, L damage is the fracturing fluid damage length, cm; n is the number of repetitions of the fracturing fluid damage experiment; L is the reservoir core length, cm; ΔL is the core length between two adjacent pressure measuring points, cm; j is the number of the jth pressure measuring point.

[0028] Furthermore, when each pressure measuring point does not meet the preset conditions, the initial inlet pressure is updated, further as follows:

[0029] In a previous fracturing fluid damage experiment, when the fracturing time reaches the preset pressure time, the outlet pressure of the core holder updates the initial inlet pressure.

[0030] Specifically, according to the fracturing fluid damage length, the parameter of reservoir matrix fracturing fluid permeability changing with invasion depth is calculated as:

[0031]

[0032] Among them, K m(i) is the permeability at the invasion depth i, 10 -3 μm 2 ; K rock is the reservoir matrix permeability, 10 -3 μm 2 ; η damage is the damage rate of fracturing fluid, dimensionless; L damage is the core fracturing fluid damage length, cm; tansig is the transfer function, and its specific calculation formula is:

[0033]

[0034] i is the penetration depth, cm.

[0035] Furthermore, according to the average seam height and seam length of the hydraulic main seam, the average seam height and seam length of the branch seam and the reservoir fracturing fluid loss depth, the total fracturing fluid loss is calculated as:

[0036]

[0037] Among them, V loss is the total filtration loss of fracturing fluid, m 3 ;D loss is the fracturing fluid loss depth, cm; K m (i) is the permeability at the invasion depth i, 10 -3 μm 2 ;H fmain is the average seam height of the hydraulic main seam, m; L fmain H is the length of the hydraulic main seam, m; fbranch1 is the average fracture height of branch fracture 1, m; L fbranch1 is the length of branch seam 1, m; H fbranch2 is the average fracture height of branch fracture 2, m; L fbranch2 is the length of branch seam 2, m; H fbranchn is the average fracture height of branch fracture n, m; L fbranchn is the length of branch seam n, m.

[0038] In a second aspect, an embodiment of the present specification provides a reservoir matrix fracturing fluid fluid loss calculation device, comprising:

[0039] An acquisition module is used to obtain the pressure data of each pressure measuring point of the core during the reservoir core fracturing fluid damage experiment;

[0040] A determination module, used to determine the fracturing fluid damage length of the reservoir core according to the pressure data;

[0041] A permeability calculation module, used to calculate the parameters of reservoir matrix fracturing fluid permeability changing with invasion depth according to the fracturing fluid damage length;

[0042] The filter loss depth calculation module is used to calculate the reservoir fracturing fluid filter loss depth according to the fracturing fluid density, fracturing fluid viscosity and the reservoir matrix fracturing fluid permeability variation with the invasion depth parameter. The reservoir fracturing fluid filter loss depth is:

[0043]

[0044] Among them, D loss is the fracturing fluid loss depth, cm; ρ fluid is the density of fracturing fluid, g / cm 3 ; K m (i) is the permeability at the invasion depth i after the fracturing fluid invasion damage, i is the invasion depth, cm; P fracture is the fluid pressure in the crack, MPa; P formation is the reservoir pore pressure, MPa; μ fluid is the fracturing fluid viscosity, mPa.s; K rock is the reservoir matrix permeability, 10 -3 μm 2 ; a, b are the reservoir matrix porosity-permeability regression coefficients, dimensionless;

[0045] The total fluid loss calculation module is used to calculate the total fluid loss of the fracturing fluid according to the average seam height and seam length of the hydraulic main seam, the average seam height and seam length of the branch seams and the fluid loss depth of the reservoir fracturing fluid.

[0046] In a third aspect, an embodiment of the present specification provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method provided by the above technical solution when executing the computer program.

[0047] By adopting the above technical scheme, a method, device and computer equipment for calculating the filtration loss of reservoir matrix fracturing fluid provided in the embodiments of this specification can take into account the influence of factors such as reservoir permeability, fracturing fluid density, and fracturing fluid viscosity, and quickly and accurately calculate the filtration loss of reservoir fracturing fluid, which is conducive to analyzing the filtration effect during the reservoir fracturing process and providing a reliable basis for the reasonable design of the reservoir fracturing fluid volume.

[0048] In order to make the above and other purposes, features and advantages of the embodiments of this specification more obvious and easy to understand, the following specifically cites preferred embodiments and describes them in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the embodiments of this specification 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 this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0050] Figure 1 A schematic diagram showing a method for calculating the fluid loss of a reservoir matrix fracturing fluid provided in an embodiment of this specification is shown;

[0051] Figure 2 A schematic diagram of the steps of determining the fracturing fluid damage length of a reservoir core according to pressure data is shown;

[0052] Figure 3 A schematic diagram of the structure of a reservoir matrix fracturing fluid filtration loss calculation device provided in an embodiment of this specification is shown;

[0053] Figure 4 A schematic diagram of the structure of a computer device provided in an embodiment of this specification is shown.

[0054] Description of the accompanying symbols:

[0055] 31. Get module;

[0056] 32. Determine the module;

[0057] 33. Permeability calculation module;

[0058] 34. Filtration depth calculation module;

[0059] 35. Total filtration loss calculation module;

[0060] 402. Computer equipment;

[0061] 404, processor;

[0062] 406. Memory;

[0063] 408. Driving mechanism;

[0064] 410, input / output module;

[0065] 412. Input devices;

[0066] 414. Output device;

[0067] 416. Presentation equipment;

[0068] 418. Graphical user interface;

[0069] 420, network interface;

[0070] 422. Communication link;

[0071] 424. Communication bus. DETAILED DESCRIPTION

[0072] The following will be combined with the drawings in the embodiments of this specification to clearly and completely describe the technical solutions in the embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments in this specification, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this specification.

[0073] It should be noted that the terms "first", "second", etc. in this specification and claims and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of this specification described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, device, product or equipment that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or equipment.

[0074] In order to solve the above problems, the embodiments of this specification provide a method, device and computer equipment for calculating the fluid loss of reservoir matrix fracturing fluid, which can solve the problem in the prior art that it is difficult to calculate the fluid loss quickly and accurately. Figure 1 This is a schematic diagram of the steps of a method for calculating the filtration loss of a reservoir matrix fracturing fluid provided in an embodiment of this specification. This specification provides method operation steps as described in the embodiment or flow chart, but may include more or fewer operation steps based on conventional or non-creative labor. The order of steps listed in the embodiment is only one way of executing the steps among many orders, and does not represent the only order of execution. When the actual system or device product is executed, it can be executed in the order of the method shown in the embodiment or the accompanying drawings or in parallel. Specifically, Figure 1 As shown, the method may include:

[0075] S110: Obtaining pressure data of each pressure measuring point of the core during the reservoir core fracturing fluid damage experiment.

[0076] S120: Determine the fracturing fluid damage length of the reservoir core according to the pressure data.

[0077] S130: Calculating a parameter of reservoir matrix fracturing fluid permeability varying with invasion depth according to the fracturing fluid damage length.

[0078] S140: Calculate the reservoir fracturing fluid loss depth according to the fracturing fluid density, the fracturing fluid viscosity and the reservoir matrix fracturing fluid permeability variation with the invasion depth parameter.

[0079] S150: Calculate the total fluid loss of the fracturing fluid according to the average fracture height and fracture length of the hydraulic main fracture, the average fracture height and fracture length of the branch fractures, and the fluid loss depth of the reservoir fracturing fluid.

[0080] The embodiment of this specification provides a method for calculating the fluid loss of reservoir matrix fracturing fluid, which can take into account the influence of factors such as reservoir permeability, fracturing fluid density, and fracturing fluid viscosity, and quickly and accurately calculate the fluid loss of reservoir fracturing fluid, which is beneficial to analyze the fluid loss effect during the reservoir fracturing process and provide a reliable basis for the reasonable design of the reservoir fracturing fluid volume.

[0081] Specifically, Figure 2 As shown, step S120: determining the fracturing fluid damage length of the reservoir core according to the pressure data may further include:

[0082] S210: Obtaining pressure data of each pressure measuring point on the core holder under the conditions of initial inlet pressure, initial outlet pressure and preset fracturing time in the fracturing fluid damage experiment.

[0083] Specifically, the reservoir fluid pressure P is obtained based on the reservoir logging data and formation test data. formation , and obtain the fluid pressure P in the fracture according to the fracturing design pumping program fracture ; The fluid pressure in the crack is P fracture is the initial inlet pressure, and the reservoir fluid pressure P formation is the initial outlet pressure. There are multiple pressure measuring points, which are evenly spaced from the inlet to the outlet of the core holder. For example, four pressure measuring points can be set, each of which is denoted by P j (j=1, 2, 3, 4), then P1 is located at the inlet end of the core holder, and P4 is located at the outlet end of the core holder.

[0084] S220: Calculate the pressure gradient difference coefficient of each pressure measuring point according to the pressure data of each pressure measuring point, the initial inlet end pressure and the initial outlet end pressure.

[0085] The pressure gradient difference coefficient is calculated by the following formula:

[0086] η i =(G Pi -G rock ) / G rock

[0087] Among them, η j is the pressure gradient difference coefficient of the jth pressure measuring point, dimensionless; G Pj is the pressure gradient corresponding to the jth pressure measuring point, MPa / cm; G rock is the pressure gradient between the outlet and inlet of the core holder, MPa / cm;

[0088] Specifically, there are:

[0089]

[0090]

[0091] Among them, P j is the pressure at the jth pressure measuring point, MPa; P j-1 is the pressure at the j-1th pressure measuring point, MPa; ΔL is the core length between two adjacent pressure measuring points, cm; P in is the pressure at the inlet of the core holder, MPa; P out is the pressure at the outlet of the core holder, MPa; L is the length of the reservoir core, cm.

[0092] S230: Determine whether there is a pressure measuring point among the pressure measuring points whose pressure gradient difference coefficient meets a preset condition.

[0093] In the embodiment of this specification, the preset condition is less than or equal to the pressure gradient difference coefficient threshold. Specifically, the pressure gradient difference coefficient threshold can be set to 0.1. Then it is judged that after the duration of the fracturing fluid damage experiment reaches the preset fracturing time, the pressure gradient difference coefficient η of each pressure measuring point j Is it less than or equal to 0.1?

[0094] S240: When there is a prediction point where the pressure gradient difference coefficient meets the preset condition, the fracturing fluid damage length is determined according to the pressure measuring point where the pressure gradient difference coefficient meets the preset condition and the number of repetitions of the fracturing fluid damage experiment.

[0095] At this time, the damage length of the fracturing fluid is:

[0096] L damage =nL+jΔL

[0097] Among them, L damage is the fracturing fluid damage length, cm; n is the number of repetitions of the fracturing fluid damage experiment; L is the reservoir core length, cm; ΔL is the core length between two adjacent pressure measuring points, cm; j is the number of the jth pressure measuring point.

[0098] It should be noted that the number of repetitions of the fracturing fluid damage experiment is the total number of actual fracturing fluid damage experiments minus 1. That is to say, when the first fracturing fluid damage experiment is completed, that is, when there is a prediction point where the pressure gradient difference coefficient meets the preset conditions, the number of repetitions of the fracturing fluid damage experiment is 0, and the fracturing fluid damage length is L. damage =jΔL.

[0099] S250: When all the pressure measuring points do not meet the preset conditions, the initial inlet pressure is updated and the fracturing fluid damage experiment is repeated at a preset fracturing time until a prediction point exists where the pressure gradient difference coefficient meets the preset conditions.

[0100] Specifically, when the pressure gradient difference coefficients of each pressure measuring point are greater than 0.1, when the fracturing time reaches the preset pressure time in the previous fracturing fluid damage experiment, the outlet pressure of the core holder (i.e., the pressure measured at the pressure measuring point P4 at this time) updates the initial inlet pressure and takes the reservoir fluid pressure P formation Repeat the fracturing fluid damage experiment on the reservoir core in the core holder at the outlet pressure and continue the preset fracturing time. At this time, the total number of fracturing fluid damage experiments is 2, and the number of repetitions of the fracturing fluid damage experiment is 1.

[0101] It is determined whether there is a pressure measuring point whose pressure gradient difference coefficient meets the preset conditions after the fracturing fluid damage experiment. If not, the inlet pressure of the core holder is updated again to repeat the fracturing fluid damage experiment until there is a pressure measuring point whose pressure gradient difference coefficient meets the preset conditions.

[0102] Further, step S130: according to the fracturing fluid damage length, the parameter of reservoir matrix fracturing fluid permeability varying with invasion depth is calculated, which is further:

[0103]

[0104] Among them, K m (i) is the permeability at the invasion depth i, 10 -3 μm 2 ; K rock is the reservoir matrix permeability, 10 -3 μm 2 ; η damage is the damage rate of fracturing fluid, dimensionless; L damage is the core fracturing fluid damage length, cm; tansig is the transfer function, and its specific calculation formula is:

[0105]

[0106] i is the penetration depth, cm.

[0107] During the reservoir fracturing process, a fluid loss reducer is usually added to the fracturing fluid system to reduce the fluid loss of the fracturing fluid and improve the efficiency of the fracturing fluid. Commonly used fluid loss reducers include silica powder, quartz powder, talcum powder, marble powder, rosin, copolymers of styrene and toluene, etc. Due to the addition of fluid loss reducers, the permeability of the reservoir matrix will change with the invasion depth. In the embodiments of this specification, when calculating the fluid loss depth of the fracturing fluid, the influence of the invasion depth is taken into account, and the original reservoir matrix permeability K m Improved to the permeability K that varies with invasion depth m (i) It can realize the calculation of reservoir fracturing fluid loss that varies with the invasion depth, which is beneficial to improve the accuracy of fluid loss calculation.

[0108] Further, step S140: according to the density of the fracturing fluid, the viscosity of the fracturing fluid and the parameters of the change of the permeability of the reservoir matrix fracturing fluid with the invasion depth, the reservoir fracturing fluid loss depth is calculated, further comprising:

[0109] The reservoir fracturing fluid loss depth is calculated according to the following formula:

[0110]

[0111] Among them, D loss is the fracturing fluid loss depth, cm; ρ fluid is the density of fracturing fluid, g / cm 3 ; K m (i) is the permeability at the invasion depth i after the fracturing fluid invasion damage, 10 -3 μm 2 ; i is the penetration depth, cm; P fracture is the fluid pressure in the crack, MPa; P formation is the reservoir pore pressure, MPa; μ fluid is the fracturing fluid viscosity, mPa.s; K rock is the reservoir matrix permeability, 10 -3 μm 2 ; a and b are the reservoir matrix porosity-permeability regression coefficients, dimensionless.

[0112] Finally, step S150: according to the average seam height and seam length of the hydraulic main seam, the average seam height and seam length of the branch seam and the reservoir fracturing fluid loss depth, the total fracturing fluid loss is calculated, which is further:

[0113]

[0114] Among them, V loss is the total filtration loss of fracturing fluid, m 3 ;D loss is the fracturing fluid loss depth, cm; K m(i) is the permeability at the invasion depth i, 10 -3 μm 2 ;H fmain is the average seam height of the hydraulic main seam, m; L fmain H is the length of the hydraulic main seam, m; fbranch1 is the average fracture height of branch fracture 1, m; L fbranch1 is the length of branch seam 1, m; H fbranch2 is the average fracture height of branch fracture 2, m; L fbranch2 is the length of branch seam 2, m; H fbranchn is the average fracture height of branch fracture n, m; L fbranchn is the length of branch seam n, m.

[0115] The total area of ​​the fracture can be defined as A f for:

[0116] A f =H fmain L fmain +H fbranch1 L fbranch1 +H fbranch2 L fbranch2 +…+H fbranchn L fbranchn

[0117] Then we have:

[0118]

[0119] The filtration area of ​​fracturing fluid is another important parameter for evaluating the filtration loss of reservoir fracturing fluid. The filtration area of ​​fracturing fluid is the sum of the areas of all fractures in contact with the fracturing fluid. Microseismic monitoring shows that the fracture network of reservoir fracturing is in the form of main fracture and branch fracture mode, among which the main fracture has the longest length and the highest fracture height; the branch fractures are more complex and have a larger number. Through the simulation of reservoir fracturing, the geometric scale data of fractures at all levels can be obtained, and then the fractures can be classified and quantified, and the parameters such as single fracture length and fracture height can be quantified, so as to realize the effective calculation of the filtration area of ​​fracturing fluid.

[0120] Through the above method, the calculation of the fracturing fluid loss in the reservoir core fracturing fluid damage experiment is realized.

[0121] In a preferred embodiment, the corresponding filtration depth of the hydraulic main seam and each branch seam can be calculated respectively to obtain the hydraulic main seam filtration depth D loss-fmain , cm; branch seam 1 filtration depth D loss-fbranch1 , cm; branch seam 2 filtration depth D loss-fbranch2 , cm; branch seam n filtration depth D loss-fbranchn , cm;

[0122] And, the matrix permeability of the hydraulic main joint and each branch joint is calculated respectively, that is, the matrix permeability of the hydraulic main joint surface K is obtained. m-fmain , 10 -3 μm 2 ; Branch fracture 1 fracture surface matrix permeability K m-fbranch1 , 10 -3 μm 2 ; Branch fracture 2 fracture surface matrix permeability K m-fbranch2 , 10 -3 μm 2 ; Branch fracture n fracture surface matrix permeability K m-fbranchn , 10 -3 μm 2 ;

[0123] Furthermore, the total filtration loss of fracturing fluid is:

[0124]

[0125] Thus, a more accurate calculation result of the total fluid loss of fracturing fluid can be obtained.

[0126] In a specific embodiment, a vertical well A-1 in a western oil field reservoir was subjected to a fracturing fluid damage experiment using a fracturing fluid system ZF-1 (fracturing fluid concentration μ fluid =30mPa.s; fracturing fluid density ρ fluid =1.08g / cm 3 ) ; Using simulated formation water with the same mineralization as formation water, the reservoir matrix permeability K is determined rock =20×10 -3 um 2 ; Through the downhole core test of the reservoir vertical well A-1, the fracturing fluid system ZF-1 has an inlet pressure P fracture =60MPa, outlet pressure P formation = Fracturing fluid damage rate η at 45MPa damage =0.45, the damage length L of the fracturing fluid to the core damage =8cm; and the reservoir matrix porosity-permeability regression coefficients a=0.0016 and b=3.3205 were calculated. The main hydraulic fracture length is 120m and the fracture height is 30m. The length of the four branch fractures is 40m and the fracture height is 30m.

[0127] Then the parameter of reservoir matrix fracturing fluid permeability changing with invasion depth is:

[0128]

[0129] Then, the calculation formula of reservoir fracturing fluid loss depth is transformed into:

[0130]

[0131] Let the intrusion depth i start from 0 and iterate until P formation(i) =P formation , then i is D loss . Get D loss =1.41cm.

[0132] According to the average fracture height and fracture length of the hydraulic main fracture and the average fracture height and fracture length of the branch fracture, the fracturing fluid loss area can be calculated as:

[0133] Af=8400m 2

[0134] Finally, the total fluid loss of fracturing fluid is:

[0135] V loss =20.287m 3

[0136] The calculation of reservoir matrix fracturing fluid loss provided in the embodiments of this specification can take into account the influence of factors such as reservoir permeability, fracturing fluid viscosity, fracturing fluid density, reservoir fluid pressure, and fluid pressure in fractures, evaluate the damage caused by fracturing fluid loss, and quickly and accurately calculate the loss amount, which can provide a reliable basis for the reasonable design of the amount of fracturing fluid required for reservoir fracturing construction; in addition, the main controlling factors of the fracturing fluid loss can be evaluated in combination with data such as well logging and core analysis.

[0137] Based on the above-mentioned method for calculating the fluid loss of a reservoir matrix fracturing fluid, the embodiments of this specification also provide a corresponding device for calculating the fluid loss of a reservoir matrix fracturing fluid. The device may include a system (including a distributed system), software (application), module, component, server, client, etc. using the method described in the embodiments of this specification and a device combined with necessary implementation hardware. Based on the same innovative concept, the device in one or more embodiments provided in the embodiments of this specification is as described in the following embodiments. Since the implementation scheme and method for solving the problem of the device are similar, the implementation of the specific device in the embodiments of this specification can refer to the implementation of the aforementioned method, and the repetitions will not be repeated. As used below, the term "unit" or "module" can implement a combination of software and / or hardware for a predetermined function. Although the device described in the following embodiments is preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceived.

[0138] like Figure 3 As shown, in the embodiment of this specification, the reservoir matrix fracturing fluid filtration loss calculation device may include:

[0139] An acquisition module 31 is used to obtain the pressure data of each pressure measuring point of the core during the reservoir core fracturing fluid damage experiment;

[0140] A determination module 32, for determining the fracturing fluid damage length of the reservoir core according to the pressure data;

[0141] The permeability calculation module 33 is used to calculate the parameter of reservoir matrix fracturing fluid permeability changing with invasion depth according to the fracturing fluid damage length;

[0142] The filter loss depth calculation module 34 is used to calculate the reservoir fracturing fluid filter loss depth according to the fracturing fluid density, the fracturing fluid viscosity and the reservoir matrix fracturing fluid permeability variation with the invasion depth parameter. The reservoir fracturing fluid filter loss depth is:

[0143]

[0144] Among them, D loss is the fracturing fluid loss depth, cm; ρ fluid is the density of fracturing fluid, g / cm 3 ; K m (i) is the permeability at the invasion depth i after the fracturing fluid invasion damage, 10 -3 μm 2 ; i is the penetration depth, cm; P fracture is the fluid pressure in the crack, MPa; P formation is the reservoir pore pressure, MPa; μ fluid is the fracturing fluid viscosity, mPa.s; K rock is the reservoir matrix permeability, 10 -3 μm 2 ; a, b are the reservoir matrix porosity-permeability regression coefficients, dimensionless;

[0145] The total fluid loss calculation module 35 is used to calculate the total fluid loss of the fracturing fluid according to the average fracture height and fracture length of the hydraulic main fracture, the average fracture height and fracture length of the branch fracture and the fluid loss depth of the reservoir fracturing fluid.

[0146] The beneficial effects obtained by the device provided in the embodiments of this specification are consistent with the beneficial effects obtained by the above method and will not be repeated here.

[0147] like Figure 4As shown, a computer device provided in an embodiment of this specification is provided. The reservoir matrix fracturing fluid loss calculation device in this specification can be a computer device in this embodiment, executing the above method of this specification. The computer device 402 may include one or more processors 404, such as one or more central processing units (CPUs), and each processing unit may implement one or more hardware threads. The computer device 402 may also include any memory 406, which is used to store any kind of information such as code, settings, data, etc. Non-limiting, for example, the memory 406 may include any one or more combinations of the following: any type of RAM, any type of ROM, flash memory device, hard disk, optical disk, etc. More generally, any memory can use any technology to store information. Further, any memory can provide volatile or non-volatile retention of information. Further, any memory can represent a fixed or removable component of the computer device 402. In one case, when the processor 404 executes an associated instruction stored in any memory or a combination of memories, the computer device 402 can perform any operation of the associated instruction. The computer device 402 also includes one or more drive mechanisms 408 for interacting with any storage, such as a hard disk drive mechanism, an optical disk drive mechanism, etc.

[0148] The computer device 402 may also include an input / output module 410 (I / O) for receiving various inputs (via input devices 412) and for providing various outputs (via output devices 414). A specific output mechanism may include a presentation device 416 and an associated graphical user interface (GUI) 418. In other embodiments, the input / output module 410 (I / O), input device 412, and output device 414 may not be included, and the computer device 402 may be used as a computer device in a network. The computer device 402 may also include one or more network interfaces 420 for exchanging data with other devices via one or more communication links 422. One or more communication buses 424 couple the components described above together.

[0149] The communication link 422 may be implemented in any manner, for example, through a local area network, a wide area network (e.g., the Internet), a point-to-point connection, etc., or any combination thereof. The communication link 422 may include any combination of hardwired links, wireless links, routers, gateway functions, name servers, etc., governed by any protocol or combination of protocols.

[0150] Corresponding to Figure 1 to Figure 2 In addition to the method shown, an embodiment of the specification also provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the above method are executed.

[0151] The embodiment of the present specification also provides a computer-readable instruction, wherein when the processor executes the instruction, the program therein causes the processor to execute the following Figure 1 to Figure 2 The method shown.

[0152] The embodiments of the present specification also provide a computer program product, including at least one instruction or at least one program, wherein the at least one instruction or the at least one program is loaded and executed by a processor to implement the following Figure 1 to Figure 2 The method shown.

[0153] It should be understood that in the various embodiments of this specification, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this specification.

[0154] It should also be understood that in the embodiments of this specification, the term "and / or" is only a description of the association relationship of the associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this specification generally indicates that the associated objects before and after are in an "or" relationship.

[0155] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed in this specification can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this specification.

[0156] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0157] In the several embodiments provided in this specification, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, or it can be an electrical, mechanical or other form of connection.

[0158] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the embodiments of this specification.

[0159] In addition, each functional unit in each embodiment of this specification may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0160] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this specification is essentially or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of this specification. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0161] Specific embodiments are used in this specification to illustrate the principles and implementation methods of this specification. The description of the above embodiments is only used to help understand the methods and core ideas of this specification. At the same time, for those skilled in the art, according to the ideas of this specification, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on this specification.

Claims

1. A method for calculating the fluid loss of reservoir matrix fracturing fluid, characterized in that: The method comprises: Obtain the pressure data of each pressure measuring point in the core during the reservoir core fracturing fluid damage experiment; Determining the fracturing fluid damage length of the reservoir core according to the pressure data; Calculating the parameter of reservoir matrix fracturing fluid permeability varying with invasion depth according to the fracturing fluid damage length; According to the density of the fracturing fluid, the viscosity of the fracturing fluid and the parameters of the change of the permeability of the reservoir matrix fracturing fluid with the invasion depth, the reservoir fracturing fluid loss depth is calculated, and the reservoir fracturing fluid loss depth is: Among them, D loss is the fracturing fluid loss depth, cm; ρ fluid is the density of fracturing fluid, g / cm 3 ; K m (i) is the permeability at the invasion depth i after the fracturing fluid invasion damage, 10 -3 μm 2 ; i is the penetration depth, cm; P fracture is the fluid pressure in the crack, MPa; P formation is the reservoir pore pressure, MPa; μ fluid is the fracturing fluid viscosity, mPa.s; K rock is the reservoir matrix permeability, 10 -3 μm 2 ; a, b are the reservoir matrix porosity-permeability regression coefficients, dimensionless; The total fluid loss of the fracturing fluid is calculated based on the average fracture height and fracture length of the hydraulic main fracture, the average fracture height and fracture length of the branch fractures, and the fluid loss depth of the reservoir fracturing fluid.

2. The method according to claim 1, characterized in that Determining the fracturing fluid damage length of the reservoir core according to the pressure data further includes: Obtain the pressure data of each pressure measuring point on the core holder under the conditions of initial inlet pressure, initial outlet pressure and preset fracturing time in the fracturing fluid damage experiment; Calculate the pressure gradient difference coefficient of each pressure measuring point according to the pressure data of each pressure measuring point, the initial inlet end pressure and the initial outlet end pressure; Determine whether there is a pressure measuring point among the pressure measuring points whose pressure gradient difference coefficient meets a preset condition; When there is a prediction point where the pressure gradient difference coefficient meets the preset condition, the fracturing fluid damage length is determined according to the pressure measuring point where the pressure gradient difference coefficient meets the preset condition and the number of repetitions of the fracturing fluid damage experiment; When all the pressure measuring points do not meet the preset conditions, the initial inlet pressure is updated and the fracturing fluid damage experiment is repeated at the preset fracturing time until there is a predicted point where the pressure gradient difference coefficient meets the preset conditions.

3. The method according to claim 2, characterized in that The pressure gradient difference coefficient is calculated according to the following formula: or j =(G Pj -G rock ) / G rock Among them, η j is the pressure gradient difference coefficient of the jth pressure measuring point, dimensionless; G Pj is the pressure gradient corresponding to the jth pressure measuring point, MPa / cm; G rock is the pressure gradient between the outlet and inlet of the core holder, MPa / cm; Among them, P j is the pressure at the jth pressure measuring point, MPa; P j-1 is the pressure at the j-1th pressure measuring point, MPa; ΔL is the core length between two adjacent pressure measuring points, cm; P in is the pressure at the inlet of the core holder, MPa; P out is the pressure at the outlet of the core holder, MPa; L is the length of the reservoir core, cm.

4. The method according to claim 3, characterized in that When there is a prediction point where the pressure gradient difference coefficient meets the preset conditions, the fracturing fluid damage length is determined according to the pressure measuring point where the pressure gradient difference coefficient meets the preset conditions and the number of repetitions of the fracturing fluid damage experiment: L damage =nL+jΔL Among them, L damage is the fracturing fluid damage length, cm; n is the number of repetitions of the fracturing fluid damage experiment; L is the reservoir core length, cm; ΔL is the core length between two adjacent pressure measuring points, cm; j is the number of the jth pressure measuring point.

5. The method according to claim 3, characterized in that: When each pressure measuring point does not meet the preset conditions, the initial inlet pressure is updated, further as follows: In a previous fracturing fluid damage experiment, when the fracturing time reaches the preset pressure time, the outlet pressure of the core holder updates the initial inlet pressure.

6. The method according to claim 1, characterized in that According to the fracturing fluid damage length, the parameters of reservoir matrix fracturing fluid permeability changing with invasion depth are calculated, which are further: Among them, K m (i) is the permeability at the invasion depth i, 10 -3 μm 2 ; K rock is the reservoir matrix permeability, 10 -3 μm 2 ; η damage is the damage rate of fracturing fluid, dimensionless; L damage is the core fracturing fluid damage length, cm; tansig is the transfer function, and its specific calculation formula is: i is the penetration depth, cm.

7. The method according to claim 1, characterized in that According to the average fracture height and fracture length of the hydraulic main fracture, the average fracture height and fracture length of the branch fracture and the reservoir fracturing fluid loss depth, the total fracturing fluid loss is calculated, which is further: Among them, V loss is the total filtration loss of fracturing fluid, m 3 ;D loss is the fracturing fluid loss depth, cm; K m (i) is the permeability at the invasion depth i, 10 -3 μm 2 ;H fmain is the average height of the hydraulic main joint, m; L fmain H is the length of the hydraulic main seam, m; fbranch1 is the average fracture height of branch fracture 1, m; L fbranch1 is the length of branch seam 1, m; H fbranch2 is the average fracture height of branch fracture 2, m; L fbranch2 is the length of branch seam 2, m; H fbranchn is the average fracture height of branch fracture n, m; L fbranchn is the length of branch seam n, m.

8. A reservoir matrix fracturing fluid filtration loss calculation device, characterized in that: include: An acquisition module is used to obtain the pressure data of each pressure measuring point of the core during the reservoir core fracturing fluid damage experiment; A determination module, used to determine the fracturing fluid damage length of the reservoir core according to the pressure data; A permeability calculation module, used to calculate the parameters of reservoir matrix fracturing fluid permeability changing with invasion depth according to the fracturing fluid damage length; The filter loss depth calculation module is used to calculate the reservoir fracturing fluid filter loss depth according to the fracturing fluid density, fracturing fluid viscosity and the reservoir matrix fracturing fluid permeability variation with the invasion depth parameter. The reservoir fracturing fluid filter loss depth is: Among them, D loss is the fracturing fluid loss depth, cm; ρ fluid is the density of fracturing fluid, g / cm 3 ; K m (i) is the permeability at the invasion depth i after the fracturing fluid invasion damage, 10 -3 μm 2 ; i is the penetration depth, cm; P fracture is the fluid pressure in the crack, MPa; P formation is the reservoir pore pressure, MPa; μ fluid is the fracturing fluid viscosity, mPa.s; K rock is the reservoir matrix permeability, 10 -3 μm 2 ; a, b are the reservoir matrix porosity-permeability regression coefficients, dimensionless; The total fluid loss calculation module is used to calculate the total fluid loss of the fracturing fluid according to the average seam height and seam length of the hydraulic main seam, the average seam height and seam length of the branch seams and the fluid loss depth of the reservoir fracturing fluid.

9. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method according to any one of claims 1 to 7 is implemented.

Images