Reservoir matrix fracturing fluid filtration loss calculation method, device and computer equipment

Abstract

This specification provides a method, apparatus, and computer equipment for calculating reservoir matrix fracturing fluid loss, relating to the field of petroleum extraction technology. The method includes acquiring pressure data at various pressure measurement points in the reservoir core during a fracturing fluid damage experiment; determining the fracturing fluid damage length of the reservoir core based on the pressure data; calculating the reservoir matrix fracturing fluid permeability as a function of invasion depth based on the fracturing fluid damage length; calculating the reservoir fracturing fluid loss depth based on the fracturing fluid density, fracturing fluid viscosity, and reservoir matrix fracturing fluid permeability as a function of invasion depth; and calculating the total fracturing fluid loss based on the average fracture height and length of the main hydraulic fracture, the average fracture height and length of the branch fractures, and the reservoir fracturing fluid loss depth. This method can consider the influence of factors such as the change in reservoir matrix fracturing fluid permeability with invasion depth, fracturing fluid density, and fracturing fluid viscosity, enabling rapid and accurate calculation of reservoir matrix fracturing fluid loss.

Description

Technical Field

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

[0002] In reservoir hydraulic fracturing, fracturing fluid loss is a crucial parameter for evaluating fracturing fluid efficiency and fracture creation scale. First, fracturing fluid loss causes a change in the effective fracturing fluid volume within the hydraulic fracture, which is the difference between the pumped fracturing fluid volume and the volume lost. The ratio of the in-fracture fracturing fluid volume to the pumped fracturing fluid volume can be defined as fracturing fluid efficiency; the higher the in-fracture fracturing fluid efficiency, the higher the fracture creation efficiency. Therefore, effectively evaluating fracturing fluid loss helps in the precise design of fracturing fluid volume, enabling the design of a reasonable fracturing fluid volume for operation, thereby achieving the target reservoir fracture volume. Second, fracturing fluid loss causes changes in the fluid pressure within the fracture. Under the same pumping rate, a larger fracturing fluid loss results in lower fluid pressure within the fracture; this leads to a smaller hydraulic fracture width, which easily increases proppant migration resistance; ultimately, the fracturing fracture conductivity will fail to meet the requirements for efficient reservoir oil and gas production. For reservoirs, the filtration loss of fracturing fluid is mainly affected by factors such as rock matrix permeability, porosity, and fracture pressure. Currently, there is a lack of methods for calculating reservoir fracturing fluid filtration loss.

[0003] In view of this, the embodiments in this specification aim to provide a method, apparatus and computer equipment for calculating reservoir matrix fracturing fluid loss. Summary of the Invention

[0004] To address the aforementioned problems in the prior art, the purpose of the embodiments in this specification is to provide a method, apparatus, and computer device for calculating fracturing fluid loss in reservoir matrix, thereby solving the problem of the lack of a method for calculating fracturing fluid loss in the prior art.

[0005] In a first aspect, embodiments of this specification provide a method for calculating the filtrate loss of reservoir matrix fracturing fluid, including:

[0006] During the reservoir core fracturing fluid damage experiment, pressure data were obtained at various pressure measurement points in the core.

[0007] Based on the pressure data, the length of fracturing fluid damage to the reservoir core is determined;

[0008] Based on the fracturing fluid damage length, calculate the parameters of reservoir matrix fracturing fluid permeability as a function of invasion depth;

[0009] Based on the parameters of fracturing fluid density, fracturing fluid viscosity, and the variation of reservoir matrix fracturing fluid permeability with penetration depth, the reservoir fracturing fluid filtration depth is calculated as follows:

[0010]

[0011] Among them, D loss ρ represents the fracturing fluid filtration depth, in cm. fluid Density of fracturing fluid, g / cm³ 3 ;K m (i) represents the permeability at depth i after fracturing fluid intrusion damage, 10 -3 μm 2 ; i represents the depth of intrusion, in cm; P fracture P represents the fluid pressure inside the slit, in MPa; formation ρ is the reservoir pore pressure, MPa; μ fluid K represents the viscosity of the fracturing fluid, in mPa·s; rock For reservoir matrix permeability, 10 -3 μm 2 a and b are the dimensionless regression coefficients of reservoir matrix porosity-permeability.

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

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

[0014] Under the conditions of initial inlet pressure, initial outlet pressure and preset fracturing time, pressure data were obtained at each pressure measuring point on the core holder in the fracturing fluid damage experiment.

[0015] Based on the pressure data at each pressure measurement point, the initial inlet pressure, and the initial outlet pressure, the pressure gradient difference coefficient at each pressure measurement point is calculated.

[0016] Determine whether there are any pressure testing points among the pressure testing points whose pressure gradient difference coefficient meets the preset conditions;

[0017] When there is a prediction point where the pressure gradient difference coefficient meets the preset conditions, the length of the fracturing fluid damage is determined based on the pressure measurement point where the pressure gradient difference coefficient meets the preset conditions and the number of repetitions of the fracturing fluid damage experiment.

[0018] When none of the pressure measurement points meet the preset conditions, the initial inlet pressure is updated and the fracturing fluid damage experiment is repeated with a preset fracturing time until a predicted point exists 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] Where, η j G is the pressure gradient difference coefficient at the j-th pressure measurement point, dimensionless; Pj G represents the pressure gradient corresponding to the j-th pressure measurement point, in MPa / cm. rock , represents the pressure gradient between the outlet and inlet ends of the core holder, in MPa / cm;

[0022]

[0023]

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

[0025] Furthermore, when there is a predicted point where the pressure gradient difference coefficient meets the preset conditions, the fracturing fluid damage length is determined based on the pressure measurement 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 denoted as 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 measurement points (cm); and j is the number of the j-th pressure measurement point.

[0028] Furthermore, when none of the pressure measurement points 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 reached the preset pressure time, the outlet pressure of the core holder updated the initial inlet pressure.

[0030] Specifically, based on the fracturing fluid damage length, the parameter of reservoir matrix fracturing fluid permeability as a function of penetration depth is calculated as follows:

[0031]

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

[0033]

[0034] i represents the depth of intrusion, in cm.

[0035] Furthermore, based on the average fracture height and length of the main hydraulic fracture, the average fracture height and length of the branch fractures, and the reservoir fracturing fluid filtration depth, the total fracturing fluid filtration loss is calculated as follows:

[0036]

[0037] Among them, V loss The total filtrate loss of fracturing fluid, m 3 ;D loss The fracturing fluid filtration depth is measured in cm; K m (i) represents the permeability at a depth of i, 10 -3 μm 2 H fmain The average joint height of the hydraulic main joint is in meters (m); L fmain H is the length of the hydraulic main joint, in meters. fbranch1 The average seam height of branch seam 1 is m; L fbranch1 The length of branch seam 1 is m; H fbranch2 The average seam height of branch seam 2 is m; L fbranch2 The length of branch seam 2 is m; H fbranchn Let n be the average seam height of the branch seam, in meters (m); L fbranchn Let n be the length of the branch seam, m.

[0038] Secondly, embodiments of this specification provide a reservoir matrix fracturing fluid loss calculation device, comprising:

[0039] The acquisition module is used to acquire pressure data at various pressure measurement points in the reservoir core during the fracturing fluid damage experiment.

[0040] The determination module is used to determine the fracturing fluid damage length of the reservoir core based on the pressure data;

[0041] The permeability calculation module is used to calculate the parameters of reservoir matrix fracturing fluid permeability as a function of penetration depth based on the fracturing fluid damage length.

[0042] The filtration depth calculation module is used to calculate the reservoir fracturing fluid filtration depth based on parameters such as fracturing fluid density, fracturing fluid viscosity, and the variation of reservoir matrix fracturing fluid permeability with penetration depth. The reservoir fracturing fluid filtration depth is:

[0043]

[0044] Among them, D loss ρ represents the fracturing fluid filtration depth, in cm. fluid Density of fracturing fluid, g / cm³ 3 ;K m (i) represents the permeability at depth i after fracturing fluid intrusion damage, where i is the intrusion depth in cm; P fracture P represents the fluid pressure inside the slit, in MPa; formation ρ is the reservoir pore pressure, MPa; μ fluid K represents the viscosity of the fracturing fluid, in mPa·s; rock For reservoir matrix permeability, 10 -3 μm 2 a and b are the dimensionless regression coefficients of reservoir matrix porosity-permeability.

[0045] The total filtration loss calculation module is used to calculate the total filtration loss of fracturing fluid based on the average fracture height and length of the main hydraulic fracture, the average fracture height and length of the branch fracture, and the filtration depth of the fracturing fluid in the reservoir.

[0046] Thirdly, embodiments of this specification provide a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method provided by the above-described technical solution.

[0047] By adopting the above technical solution, the reservoir matrix fracturing fluid filtration loss calculation method, device and computer equipment 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 reservoir fracturing fluid filtration loss. This is beneficial for analyzing the filtration loss effect in the reservoir fracturing process and for providing a reliable basis for the rational design of reservoir fracturing fluid volume.

[0048] To make the above and other objects, features and advantages of the embodiments of this specification more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0049] To more clearly illustrate the technical solutions in the embodiments or prior art of this specification, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this specification. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0050] Figure 1 This diagram illustrates a structural schematic of a method for calculating reservoir matrix fracturing fluid filtrate loss according to an embodiment of this specification.

[0051] Figure 2 A schematic diagram illustrating the steps for determining the fracturing fluid damage length of a reservoir core based on pressure data is shown.

[0052] Figure 3 This specification shows a schematic diagram of a reservoir matrix fracturing fluid loss calculation device provided in an embodiment of the present specification;

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

[0054] Explanation of symbols in the attached drawings:

[0055] 31. Acquisition Module;

[0056] 32. Determine the module;

[0057] 33. Permeability calculation module;

[0058] 34. Filtering depth calculation module;

[0059] 35. Total Filtration Loss Calculation Module;

[0060] 402. Computer equipment;

[0061] 404, Processor;

[0062] 406. Memory;

[0063] 408. Drive mechanism;

[0064] 410. Input / output module;

[0065] 412. Input devices;

[0066] 414. Output devices;

[0067] 416. Presentation equipment;

[0068] 418. Graphical User Interface;

[0069] 420. Network interface;

[0070] 422. Communication link;

[0071] 424. Communication bus. Detailed Implementation

[0072] The technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this specification, and not all embodiments. Based on the embodiments in this specification, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this specification.

[0073] It should be noted that the terms "first," "second," etc., used in this specification, claims, and the foregoing drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, apparatus, product, or device that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices.

[0074] To address the aforementioned issues, this specification provides a method, apparatus, and computer for calculating reservoir matrix fracturing fluid loss, which solves the problem of difficulty in quickly and accurately calculating fluid loss in the prior art. Figure 1 This diagram illustrates the steps of a method for calculating the filtrate loss of fracturing fluid in a reservoir matrix, as provided in the embodiments of this specification. This specification provides the operational steps of the method described in the embodiments or flowcharts, but based on conventional or non-inventive labor, more or fewer operational steps may be included. The order of steps listed in the embodiments is merely one possible execution order among many and does not represent the only possible execution order. In actual system or device products, the methods shown in the embodiments or drawings can be executed sequentially or in parallel. Specifically, as shown in the diagrams... Figure 1 As shown, the method may include:

[0075] S110: Obtain pressure data at each pressure measurement point in the reservoir core during the fracturing fluid damage experiment.

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

[0077] S130: Calculate the parameters of reservoir matrix fracturing fluid permeability as a function of invasion depth based on the fracturing fluid damage length.

[0078] S140: The reservoir fracturing fluid loss depth is calculated based on the parameters of fracturing fluid density, fracturing fluid viscosity, and the change of reservoir matrix fracturing fluid permeability with the depth of invasion.

[0079] S150: The total fracturing fluid loss is calculated based on the average fracture height and length of the main hydraulic fracture, the average fracture height and length of the branch fracture, and the fracturing fluid loss depth of the reservoir.

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

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

[0082] S210: Obtain pressure data at 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 reservoir logging data and formation testing data. formation And obtain the intra-fracturing fluid pressure P according to the fracturing design pumping procedure. fracture ; with fluid pressure P inside the seam fracture The initial inlet pressure is given by the reservoir fluid pressure P. formation This represents the initial outlet pressure. Multiple pressure measuring points are set up and evenly spaced from the inlet to the outlet of the core holder. For example, four pressure measuring points can be set up, each denoted as 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 based on the pressure data of each pressure measuring point, the initial inlet pressure, and the initial outlet pressure.

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

[0086] η j =(G Pj -G rock ) / G rock

[0087] Where, η j G is the pressure gradient difference coefficient at the j-th pressure measurement point, dimensionless; Pj G represents the pressure gradient corresponding to the j-th pressure measurement point, in MPa / cm. rock , represents the pressure gradient between the outlet and inlet ends of the core holder, in MPa / cm;

[0088] Specifically, there are:

[0089]

[0090]

[0091] Among them, P j P is the pressure at the j-th pressure measurement point, in MPa; j-1 P represents the pressure at the (j-1)th pressure measuring point, in MPa; ΔL represents the core length between two adjacent pressure measuring points, in cm; in P represents the pressure at the inlet end of the core holder, in MPa; out ρ 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 are any pressure test points among the pressure test points whose pressure gradient difference coefficient meets the preset conditions.

[0093] In this embodiment of the specification, the preset condition is that it 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 determined that after the fracturing fluid damage experiment has reached the preset fracturing time, the pressure gradient difference coefficient η at each pressure measurement 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 conditions, the length of the fracturing fluid damage is determined based on the pressure measurement point where the pressure gradient difference coefficient meets the preset conditions and the number of times the fracturing fluid damage experiment is repeated.

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

[0096] L damage =nL+jΔL

[0097] Among them, L damage denoted as 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 measurement points (cm); and j is the number of the j-th pressure measurement 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. In other words, if a predicted point exists where the pressure gradient difference coefficient meets the preset conditions immediately after the first fracturing fluid damage experiment, 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 none of the pressure measurement points meet the preset conditions, update the initial inlet pressure and repeat the fracturing fluid damage experiment with a preset fracturing time until there is a predicted point where the pressure gradient difference coefficient meets the preset conditions.

[0100] Specifically, when the pressure gradient difference coefficient at each pressure measuring point is greater than 0.1, the initial inlet pressure is updated by the outlet pressure of the core holder (i.e., the pressure measured at pressure measuring point P4 at this time) when the fracturing time reaches the preset pressure time in the previous fracturing fluid damage experiment, and the reservoir fluid pressure P is used as the reservoir fluid pressure. formation To test the fracturing fluid damage to the reservoir core located in the core holder under outlet pressure, repeated fracturing fluid tests were conducted for a preset fracturing time. In this case, the total number of fracturing fluid damage tests was 2, and the number of repetitions of the fracturing fluid damage test was 1.

[0101] Determine whether there are pressure measurement points where the pressure gradient difference coefficient meets the preset conditions after this fracturing fluid damage experiment. If not, update the inlet pressure of the core holder again to repeat the fracturing fluid damage experiment until a pressure measurement point has a pressure gradient difference coefficient that meets the preset conditions.

[0102] Further, step S130: Based on the fracturing fluid damage length, calculate the parameter of reservoir matrix fracturing fluid permeability as a function of invasion depth, which is further:

[0103]

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

[0105]

[0106] i represents the depth of intrusion, in cm.

[0107] During reservoir fracturing, filtration reducers are typically added to the fracturing fluid system to decrease filtration loss and improve fracturing fluid efficiency. Commonly used filtration reducers include silica powder, quartz powder, talc powder, marble powder, rosin, and copolymers of styrene and toluene. Due to the addition of filtration reducers, the permeability of the reservoir matrix changes with the depth of invasion. In the embodiments of this specification, the influence of the depth of invasion is considered when calculating the fracturing fluid filtration depth, and the original reservoir matrix permeability K is... m Improved to permeability K varying with penetration depth m (i) can calculate the reservoir fracturing fluid loss as the depth of invasion changes, which is beneficial to improving the accuracy of the loss calculation.

[0108] Further, step S140: Based on the parameters of fracturing fluid density, fracturing fluid viscosity, and the variation of reservoir matrix fracturing fluid permeability with penetration depth, the reservoir fracturing fluid loss depth is calculated, further as follows:

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

[0110]

[0111] Among them, D loss ρ represents the fracturing fluid filtration depth, in cm. fluid Density of fracturing fluid, g / cm³ 3 ;K m (i) represents the permeability at depth i after fracturing fluid intrusion damage, 10 -3 μm 2 ; i represents the depth of intrusion, in cm; P fracture P represents the fluid pressure inside the slit, in MPa; formation ρ is the reservoir pore pressure, MPa; μ fluid K represents the viscosity of the fracturing fluid, in mPa·s; rock For reservoir matrix permeability, 10 -3 μm 2 a and b are the dimensionless regression coefficients of reservoir matrix porosity-permeability.

[0112] Finally, in step S150: based on the average fracture height and length of the main hydraulic fracture, the average fracture height and length of the branch fractures, and the reservoir fracturing fluid filtration depth, the total fracturing fluid filtration loss is calculated, further as follows:

[0113]

[0114] Among them, V loss The total filtrate loss of fracturing fluid, m 3 ;D loss The fracturing fluid filtration depth is measured in cm; Km (i) represents the permeability at a depth of i, 10 -3 μm 2 H fmain The average joint height of the hydraulic main joint is in meters (m); L fmain H is the length of the hydraulic main joint, in meters. fbranch1 The average seam height of branch seam 1 is m; L fbranch1 The length of branch seam 1 is m; H fbranch2 The average seam height of branch seam 2 is m; L fbranch2 The length of branch seam 2 is m; H fbranchn Let n be the average seam height of the branch seam, in meters (m); L fbranchn Let n be the length of the branch seam, m.

[0115] The total area A of the fracturing fractures can be defined. 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 assessing reservoir fracturing fluid loss. The filtration area is the sum of the areas of all fractures in contact with the fracturing fluid. Microseismic monitoring indicates that reservoir fracturing forms a fracture network of main fractures and branch fractures, with the main fractures having the longest length and greatest height; branch fractures are more complex and numerous. By simulating reservoir fracturing, geometrical data of fractures at various levels can be obtained, allowing for fracture classification and quantification of parameters such as single fracture length and height, thus enabling the effective calculation of the fracturing fluid filtration area.

[0120] The above method enables the calculation of fracturing fluid loss in reservoir core fracturing fluid damage experiments.

[0121] In a preferred embodiment, the filtration depth of the main hydraulic joint and each branch joint can be calculated separately to obtain the filtration depth D of the main hydraulic joint. 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] Furthermore, the matrix permeability of the hydraulic main joint and each branch joint is calculated separately, thus obtaining the matrix permeability K of the hydraulic main joint. m-fmain 10 -3 μm 2 ; Branch joint 1 joint surface matrix permeability K m-fbranch1 10 -3 μm 2 ; Branch joint 2 joint surface matrix permeability K m-fbranch2 10 -3 μm 2 Branch joint n joint surface matrix permeability K m-fbranchn 10 -3 μm 2 ;

[0123] Therefore, the total filtrate loss of fracturing fluid is:

[0124]

[0125] This allows for a more accurate calculation of the total filtration loss of fracturing fluid.

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

[0127] The parameters for the variation of reservoir matrix fracturing fluid permeability with invasion depth are:

[0128]

[0129] Furthermore, the formula for calculating the reservoir fracturing fluid loss depth is transformed as follows:

[0130]

[0131] This causes the intrusion depth i to iterate from 0 until P. formation(i) =P formation At this point, i is D. loss D was obtained. loss =1.41cm.

[0132] Based on the average fracture height and length of the main hydraulic fracture and the average fracture height and length of the branch fractures, the fracturing fluid filtration area can be calculated as follows:

[0133] A f =8400m 2

[0134] Ultimately, the total filtrate loss of the fracturing fluid was:

[0135] V loss =20.287m 3

[0136] The reservoir matrix fracturing fluid loss calculation 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 fracture fluid pressure. It can assess the damage caused by fracturing fluid loss and quickly and accurately calculate the loss, providing a reliable basis for the rational design of the fracturing fluid volume required for reservoir fracturing operations. In addition, it can also combine data from well logging and core analysis to evaluate the main controlling factors of fracturing fluid loss.

[0137] Based on the above-described method for calculating the filtrate loss of reservoir matrix fracturing fluid, this specification also provides a corresponding device for calculating the filtrate loss of 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, combined with necessary implementation hardware. Based on the same innovative concept, the devices in one or more embodiments provided in this specification are as described in the following embodiments. Since the implementation schemes and methods for solving the problem by the devices are similar, the implementation of the specific devices in the embodiments of this specification can refer to the implementation of the aforementioned method, and repeated details will not be repeated. As used below, the terms "unit" or "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

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

[0139] The acquisition module 31 is used to acquire pressure data at each pressure measurement point of the core during the reservoir core fracturing fluid damage experiment.

[0140] The determination module 32 is used to determine the fracturing fluid damage length of the reservoir core based on the pressure data;

[0141] The permeability calculation module 33 is used to calculate the parameters of reservoir matrix fracturing fluid permeability as a function of penetration depth based on the fracturing fluid damage length.

[0142] The filtration depth calculation module 34 is used to calculate the reservoir fracturing fluid filtration depth based on parameters such as fracturing fluid density, fracturing fluid viscosity, and the variation of reservoir matrix fracturing fluid permeability with penetration depth. The reservoir fracturing fluid filtration depth is:

[0143]

[0144] Among them, D loss ρ represents the fracturing fluid filtration depth, in cm. fluid Density of fracturing fluid, g / cm³ 3 ;K m (i) represents the permeability at depth i after fracturing fluid intrusion damage, 10 -3 μm 2 ; i represents the depth of intrusion, in cm; P fracture P represents the fluid pressure inside the slit, in MPa; formation ρ is the reservoir pore pressure, MPa; μ fluid K represents the viscosity of the fracturing fluid, in mPa·s; rock For reservoir matrix permeability, 10 -3 μm 2 a and b are the dimensionless regression coefficients of reservoir matrix porosity-permeability.

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

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

[0147] like Figure 4The diagram illustrates a computer device provided in an embodiment of this specification. The reservoir matrix fracturing fluid loss calculation device in this specification can be the computer device in this embodiment, executing the methods described above. The computer device 402 may include one or more processors 404, such as one or more central processing units (CPUs), each of which can implement one or more hardware threads. The computer device 402 may also include any memory 406 for storing any kind of information, such as code, settings, data, etc. Non-limitingly, for example, memory 406 may include any type of RAM, any type of ROM, flash memory, 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 processor 404 executes associated instructions stored in any memory or combination of memories, the computer device 402 can perform any operation of the associated instructions. The computer device 402 also includes one or more drive mechanisms 408 for interacting with any memory, such as a hard disk drive mechanism, an optical disk drive mechanism, etc.

[0148] Computer device 402 may also include an input / output module 410 (I / O) for receiving various inputs (via input device 412) and providing various outputs (via output device 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 be omitted, and the device may function solely as a computer device within a network. 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] Communication link 422 can be implemented in any way, such as via a local area network, a wide area network (e.g., the Internet), a point-to-point connection, or any combination thereof. 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, for example Figures 1 to 2 In addition to the method shown, embodiments of this specification also provide a computer-readable storage medium storing a computer program that, when executed by a processor, performs the steps of the above-described method.

[0151] This specification also provides computer-readable instructions, wherein when a processor executes the instructions, the program therein causes the processor to perform the following... Figures 1 to 2 The method shown.

[0152] This specification also provides a computer program product, including at least one instruction or at least one program segment, wherein the at least one instruction or the at least one program segment is loaded and executed by a processor to achieve the following: Figures 1 to 2 The method shown.

[0153] It should be understood that in the various embodiments of this specification, the sequence number of each process does not imply 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 merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this specification generally indicates that the preceding and following related objects have an "or" relationship.

[0155] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed in this specification can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of each example have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this specification.

[0156] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing 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, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the couplings or direct couplings or communication connections shown or discussed may be indirect couplings or communication connections through some interfaces, devices, or units, or they may be electrical, mechanical, or other forms of connection.

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

[0159] Furthermore, the functional units in the various embodiments of this specification can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0160] If the integrated unit is implemented as 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, in essence, 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. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this specification. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0161] This specification uses specific embodiments to illustrate the principles and implementation methods of this specification. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this specification. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this specification. Therefore, the content of this specification should not be construed as a limitation of this specification.

Claims

1. A method for calculating the filtrate loss of fracturing fluid in a reservoir matrix, characterized in that, The method includes: During the reservoir core fracturing fluid damage experiment, pressure data were obtained at various pressure measurement points in the core. Based on the pressure data, the length of fracturing fluid damage to the reservoir core is determined; Based on the fracturing fluid damage length, calculate the parameters of reservoir matrix fracturing fluid permeability as a function of invasion depth; Based on the parameters of fracturing fluid density, fracturing fluid viscosity, and the variation of reservoir matrix fracturing fluid permeability with penetration depth, the reservoir fracturing fluid filtration depth is calculated as follows: in, The depth of fracturing fluid loss, in cm; Density of fracturing fluid, g / cm³ 3 ; The depth of penetration after fracturing fluid intrusion damage i Permeability at location, 10 -3 μm 2 ; i The depth of penetration is expressed in centimeters. The fluid pressure inside the slit is MPa. The reservoir pore pressure is expressed in MPa. The viscosity of the fracturing fluid is mPa·s. For reservoir matrix permeability, 10 -3 μm 2 ; , where is the dimensionless regression coefficient of reservoir matrix porosity-permeability; The total fracturing fluid loss is calculated based on the average fracture height and length of the main hydraulic fracture, the average fracture height and length of the branch fracture, and the fracturing fluid loss depth of the reservoir. Based on the average fracture height and length of the main hydraulic fracture, the average fracture height and length of the branch fractures, and the reservoir fracturing fluid filtration depth, the total fracturing fluid filtration loss is calculated, further as follows: in, The total filtrate loss of fracturing fluid, m 3 ; The depth of fracturing fluid loss, in cm; For the depth of intrusion i Location penetration, 10 -3 μm 2 ; The average joint height of the hydraulic main joint is in meters (m). The length of the hydraulic main joint is in meters (m). The average seam height of branch seam 1 is in meters (m). The length of branch seam 1 is in meters. The average seam height of branch seam 2 is in meters. The length of branch seam 2 is in meters. Let n be the average seam height of the branch seam, in meters. Let n be the length of the branch seam, m.

2. The method according to claim 1, characterized in that, Based on the pressure data, determining the fracturing fluid damage length of the reservoir core further includes: Under the conditions of initial inlet pressure, initial outlet pressure and preset fracturing time, pressure data were obtained at each pressure measuring point on the core holder in the fracturing fluid damage experiment. Based on the pressure data at each pressure measuring point, the initial inlet pressure, and the initial outlet pressure, the pressure gradient difference coefficient at each pressure measuring point is calculated. Determine whether there are any pressure measurement points among the pressure measurement points whose pressure gradient difference coefficient meets the preset conditions; When there is a pressure measurement point where the pressure gradient difference coefficient meets the preset condition, the length of the fracturing fluid damage is determined based on the pressure measurement point where the pressure gradient difference coefficient meets the preset condition and the number of times the fracturing fluid damage experiment is repeated. When none of the pressure measurement points meet the preset conditions, the initial inlet pressure is updated and the fracturing fluid damage experiment is repeated with a preset fracturing time until a pressure measurement point exists that meets the preset conditions for the pressure gradient difference coefficient.

3. The method according to claim 2, characterized in that, The pressure gradient difference coefficient is calculated according to the following formula: in, For the first j Pressure gradient difference coefficient at each pressure measurement point, dimensionless; For the first j Pressure gradient corresponding to each pressure measurement point, MPa / cm; The pressure gradient between the outlet and inlet ends of the core holder is expressed in MPa / cm. in, For the first j Pressure at each pressure measurement point, MPa; For the first j - Pressure at one pressure measurement point, MPa; The length of the core sample between two adjacent pressure measurement points, in cm; The pressure at the inlet end of the core holder, in MPa; The pressure at the outlet of the core holder is in MPa. , where is the length of the reservoir core, in cm.

4. The method according to claim 3, characterized in that, When a pressure measurement point exists that satisfies the preset condition for the pressure gradient difference coefficient, the fracturing fluid damage length is determined based on the pressure measurement point that satisfies the preset condition for the pressure gradient difference coefficient and the number of repetitions of the fracturing fluid damage experiment: in, The length of the fracturing fluid damage is in centimeters. n The number of repetitions of the fracturing fluid damage experiment; The length of the reservoir core is in cm. The length of the core sample between two adjacent pressure measurement points, in cm; j For the first j Each pressure measurement point is numbered.

5. The method according to claim 3, characterized in that, When none of the pressure measurement points meet the preset conditions, the initial inlet pressure is updated, further as follows: In a previous fracturing fluid damage experiment, when the fracturing time reached the preset pressure time, the outlet pressure of the core holder updated the initial inlet pressure.

6. The method according to claim 1, characterized in that, Based on the fracturing fluid damage length, the parameters of reservoir matrix fracturing fluid permeability as a function of invasion depth are calculated, further as follows: in, For the depth of intrusion i Location penetration, 10 -3 μm 2 ; For reservoir matrix permeability, 10 -3 μm 2 ; The fracturing fluid damage rate is dimensionless. The length of the core fracturing fluid damage is in centimeters. The transfer function is specifically calculated as follows: i The depth of penetration is expressed in centimeters.

7. A device for calculating the filtrate loss of reservoir matrix fracturing fluid, characterized in that, include: The acquisition module is used to acquire pressure data at various pressure measurement points in the reservoir core during the fracturing fluid damage experiment. The determination module is used to determine the fracturing fluid damage length of the reservoir core based on the pressure data; The permeability calculation module is used to calculate the parameters of reservoir matrix fracturing fluid permeability as a function of penetration depth based on the fracturing fluid damage length. The filtration depth calculation module is used to calculate the reservoir fracturing fluid filtration depth based on parameters such as fracturing fluid density, fracturing fluid viscosity, and the variation of reservoir matrix fracturing fluid permeability with penetration depth. The reservoir fracturing fluid filtration depth is: in, The depth of fracturing fluid loss, in cm; Density of fracturing fluid, g / cm³ 3 ; The depth of penetration after fracturing fluid intrusion damage i Permeability at location, 10 -3 μm 2 ; i The depth of penetration is expressed in centimeters. The fluid pressure inside the slit is MPa. The reservoir pore pressure is expressed in MPa. The viscosity of the fracturing fluid is mPa·s. For reservoir matrix permeability, 10 -3 μm 2 ; , where is the dimensionless regression coefficient of reservoir matrix porosity-permeability; The total filtration loss calculation module is used to calculate the total filtration loss of fracturing fluid based on the following formula, according to the average fracture height and length of the main hydraulic fracture, the average fracture height and length of the branch fracture, and the filtration depth of the reservoir fracturing fluid: in, The total filtrate loss of fracturing fluid, m 3 ; The depth of fracturing fluid loss, in cm; For the depth of intrusion i Location penetration, 10 -3 μm 2 ; The average joint height of the hydraulic main joint is in meters (m). The length of the hydraulic main joint is in meters (m). The average seam height of branch seam 1 is in meters (m). The length of branch seam 1 is in meters. The average seam height of branch seam 2 is in meters. The length of branch seam 2 is in meters. Let n be the average seam height of the branch seam, in meters. Let n be the length of the branch seam, m.

8. 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, it implements the method as described in any one of claims 1 to 6.

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