Method and device for determining reasonable liquid volume in sandstone reservoir fracture conductivity stage and medium

Abstract

This invention relates to a method for determining a reasonable fluid production rate during the fracture guidance stage of sandstone reservoirs, comprising: obtaining the daily fluid production rate and pressure drop per cubic meter of the oil well under different well opening pressures; establishing a pressure drop mathematical model based on the obtained daily fluid production rate and pressure drop per cubic meter under different well opening pressures; obtaining a first curve showing the relationship between daily fluid production rate and pressure drop per cubic meter based on the pressure drop mathematical model; measuring the maximum self-flowing fluid production rate under different well opening pressures; obtaining a second curve showing the maximum self-flowing fluid production rate and pressure drop per cubic meter under different well opening pressures based on the maximum self-flowing fluid production rate, daily fluid production rate, and pressure drop per cubic meter under different well opening pressures; and determining the range of the daily fluid production rate of the oil well based on the first curve and the second curve. This invention can clearly define a reasonable daily fluid production rate, ensuring long-term stable production of the oil well while taking into account a certain flowback rate.

Description

Technical Field

[0001] This invention relates to the field of oil and gas extraction technology, and in particular to a method, apparatus, and computer-readable storage medium for determining the appropriate fluid volume during the fracture diversion stage of sandstone reservoirs. Background Technology

[0002] Hydraulic fracturing is one of the most effective measures for increasing oil and gas reservoir production and improving recovery rates. With the widespread use of hydraulic fracturing technology in the exploration and development of low-permeability oil and gas fields and other industrial production fields, its theoretical methods, processes, equipment and tools have all developed rapidly.

[0003] In practice, the smooth and timely drainage of fracturing fluid has a significant impact on the operational results, especially in low-permeability and low-pressure formations. Due to difficulties in flowback, residual fluid may cause further damage to the formation, affecting production enhancement. Studies have shown that after fracturing, to prevent secondary damage caused by long-term retention of residual fluid in the formation, residual fluid should generally be drained as quickly as possible. In actual operations, insufficient understanding of the formation, improper selection of working fluids and additives, or unreasonable construction techniques often result in low flowback rates, causing damage to the reservoir. Therefore, flowback plays a crucial role in fracturing and acidizing processes. Failure to drain the fluid in a timely and complete manner can cause further damage to the formation, and the quality of flowback directly affects the effectiveness of the fracturing measures. Since this process occurs during fracture closure, a proper flowback procedure is often key to maintaining good fracture conductivity. The production capacity of post-fracturing oil and gas fields largely depends on fracture conductivity. During fracturing fluid flowback, engineers often aim to control the flowback flow rate to ensure good proppant placement in the production zone, thereby maximizing fracture conductivity. However, because it is difficult to accurately grasp the fracture closure, proppant migration, fracturing fluid loss, and changes in fluid properties during the shut-in period or flowback process, the control of flowback flow rate often seems to lack a basis.

[0004] Due to the aforementioned complexity, there has been no satisfactory solution internationally to date for improving the conductivity of fractures during fracturing fluid flowback. Determining the appropriate fluid volume during the fracture conductivity stage of the flowback process has thus become a hot topic of exploration for scientists and engineers both at home and abroad. Summary of the Invention

[0005] To address the aforementioned problems, the purpose of this invention is to provide a method, apparatus, and computer-readable storage medium for determining the reasonable daily production volume during the fracture diversion stage of sandstone reservoirs. This method clarifies the reasonable daily production volume and ensures long-term stable production of oil wells while taking into account a certain flowback rate.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] In a first aspect, this application provides a method for determining the reasonable fluid volume during the fracture conduction stage of a sandstone reservoir, the method comprising:

[0008] Obtain the daily fluid production and pressure drop per cubic meter of oil well under different well opening pressures;

[0009] Based on the obtained daily fluid production and pressure drop per cubic meter under different well opening pressures, a pressure drop mathematical model is established.

[0010] Based on the pressure drop mathematical model, the first curve showing the relationship between daily liquid production and pressure drop per cubic meter is obtained;

[0011] The ultimate self-flowing fluid production rate under different well opening pressures was measured. Based on the ultimate self-flowing fluid production rate, daily fluid production rate and pressure drop per cubic meter under different well opening pressures, a second curve of the ultimate self-flowing fluid production rate and pressure drop per cubic meter under different well opening pressures was obtained.

[0012] Based on the first curve and the second curve, the range of daily fluid production of the oil well is determined.

[0013] In one implementation of this application, obtaining the daily fluid production and pressure drop per cubic meter of the oil well under different well opening pressures includes:

[0014] The daily fluid production of the oil well is obtained by a flow meter installed at the wellhead.

[0015] The oil pressure at the wellhead is obtained in real time by a pressure gauge installed at the wellhead, and the well opening pressure and the pressure drop per cubic meter at the wellhead for each cubic meter of fluid extracted are obtained based on the real-time oil pressure.

[0016] In one implementation of this application, establishing the voltage drop mathematical model includes:

[0017] Based on the data of daily fluid production and pressure drop per cubic meter obtained from oil wells under different well opening pressures, a mathematical model is obtained by fitting the data to obtain a mathematical model in which the well opening pressure, daily fluid production, and pressure drop per cubic meter satisfy a preset functional relationship.

[0018] In one implementation of this application, the mathematical model of the preset functional relationship is:

[0019] ΔP=a×p b ×V c

[0020] Where ΔP is the pressure drop per cubic meter at the wellhead for every cubic meter of fluid produced; p is the well opening pressure; V is the daily fluid production; and a, b, and c are correction coefficients to be fitted.

[0021] The pressure drop value ΔP per cubic meter ranges from 0.0016 to 0.003 MPa.

[0022] Daily production fluid V and oil pressure P at the wellhead t The relationship is:

[0023] In the formula, m and n are dimensionless coefficients related to the nozzle opening, and their values ​​are determined based on a lookup table method: when the nozzle opening is 3mm, m = 12.822, n = 0.6918; when the nozzle opening is 3.5mm, m = 18.619, n = 0.6766; when the nozzle opening is 4.0mm, m = 39.859, n = 0.4792; when the nozzle opening is 4.5mm, m = 56.245, n = 0.4314; when the nozzle opening is 5mm, m = 78.343, n = 0.3784; when the nozzle opening is 5.5mm, m = 113.845, n = 0.3329; when the nozzle opening is 6mm, m = 145.639, n = 0.2834.

[0024] In one implementation of this application, the daily liquid production in the first curve increases as the pressure drop per cubic meter increases.

[0025] In one implementation of this application, in the second curve, while keeping the well opening pressure constant, the ultimate self-flowing fluid production rate decreases as the pressure drop per cubic meter increases.

[0026] In one implementation of this application, determining the range of daily fluid production of the oil well includes:

[0027] The lower limit of daily fluid production is determined based on the intersection of the second curve and the first curve, which are set at the preset minimum well opening pressure; and

[0028] The upper limit of daily fluid production is determined based on the intersection of the second curve and the first curve at the preset highest well opening pressure.

[0029] After determining the range of daily fluid production of the oil well, the method further includes:

[0030] The oil pressure is controlled by adjusting the opening of the oil nozzle, thereby regulating the daily liquid production and keeping the daily liquid production value within a certain range.

[0031] Secondly, this application provides a device for determining the reasonable fluid volume during the fracture conduction stage of a sandstone reservoir, the device comprising:

[0032] The measurement module is used to obtain the daily fluid production and pressure drop per cubic meter of oil well under different well opening pressures;

[0033] The model fitting module is used to establish a pressure drop mathematical model based on the daily fluid production and pressure drop per cubic meter under the obtained different well opening pressures.

[0034] The first curve calculation module is used to obtain the first curve relating the daily liquid production to the pressure drop value per cubic meter based on the pressure drop mathematical model.

[0035] The second curve calculation module is used to measure the ultimate self-flowing fluid production under different well opening pressures. Based on the ultimate self-flowing fluid production, daily fluid production and pressure drop per cubic meter under different well opening pressures, the second curve of the ultimate self-flowing fluid production and pressure drop per cubic meter under different well opening pressures is obtained.

[0036] The range calculation module is used to determine the range of daily fluid production of the oil well based on the first curve and the second curve.

[0037] Thirdly, this application provides a computer-readable storage medium storing a computer program, wherein the computer program, when running, controls the device where the computer-readable storage medium is located to execute the method for determining the reasonable fluid volume during the fracture diversion stage of sandstone reservoirs as described in the first aspect.

[0038] Fourthly, this application provides a computer device, characterized in that it includes a processor and a memory; the memory stores a computer program; the processor runs the computer program to control the computer device to execute the method for determining the reasonable fluid volume in the fracture diversion stage of sandstone reservoirs as described in the first aspect.

[0039] The present invention has the following advantages due to the adoption of the above technical solutions: The present invention obtains the daily fluid production and pressure drop per cubic meter of oil wells under different well opening pressures, then establishes a pressure drop mathematical model, and then obtains a first curve showing the relationship between daily fluid production and pressure drop per cubic meter based on the pressure drop mathematical model; and measures the limit self-flowing fluid production under different well opening pressures, and obtains a second curve showing the limit self-flowing fluid production and pressure drop per cubic meter under different well opening pressures based on the limit self-flowing fluid production, daily fluid production and pressure drop per cubic meter of oil wells under different well opening pressures, and determines the range of daily fluid production of oil wells based on the first curve and the second curve, thereby clarifying a reasonable daily fluid production and ensuring long-term stable production of oil wells while taking into account a certain flowback rate. Attached Figure Description

[0040] Figure 1 This is a flowchart illustrating a method for determining the reasonable fluid volume during the fracture conduction stage of a sandstone reservoir, as provided in this application.

[0041] Figures 2a to 2c This is a schematic diagram of the fitting of the mathematical model of pressure drop in this application;

[0042] Figure 3 This is a schematic diagram illustrating how a reasonable daily liquid production volume is determined using a first curve and a second curve, according to an embodiment of the present invention. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention are within the scope of protection of the present invention.

[0044] To address the problem of the need for providing a reasonable range of daily fluid production during the fracture conduction stage in existing technologies, this invention provides a method, apparatus, and computer-readable storage medium for determining a reasonable fluid production rate during the fracture conduction stage in sandstone reservoirs. The method includes: acquiring the daily fluid production rate and pressure drop per cubic meter of the oil well under different well opening pressures; establishing a pressure drop mathematical model based on the acquired daily fluid production rate and pressure drop per cubic meter; obtaining a first curve showing the relationship between daily fluid production rate and pressure drop per cubic meter based on the pressure drop mathematical model; measuring the maximum self-flowing fluid production rate under different well opening pressures; obtaining a second curve showing the maximum self-flowing fluid production rate and pressure drop per cubic meter under different well opening pressures based on the maximum self-flowing fluid production rate, daily fluid production rate, and pressure drop per cubic meter; and determining the range of the daily fluid production rate of the oil well based on the first and second curves. This invention can clearly define a reasonable daily fluid production rate, ensuring long-term stable production of the oil well while considering a certain flowback rate.

[0045] Please refer to the accompanying drawings of the embodiments of the present invention for further details on the methods, apparatus and media provided by the present invention in the more detailed embodiments of the present invention.

[0046] like Figure 1 In one aspect of this application, a method for determining the reasonable fluid volume during the fracture conduction stage of a sandstone reservoir is provided, specifically including:

[0047] S1, obtain the daily fluid production and pressure drop per cubic meter of oil well under different well opening pressures;

[0048] Specifically, a large amount of measurement data from actual production oil wells was used as a sample. The daily fluid production of the oil well was obtained by using a flow meter installed at the wellhead; the well opening pressure and the pressure drop per cubic meter at the wellhead for each cubic meter of fluid produced were obtained by using a pressure gauge installed at the wellhead.

[0049] S2. Based on the obtained daily fluid production and pressure drop per cubic meter under different well opening pressures, establish a pressure drop mathematical model.

[0050] Specifically, based on the data of daily fluid production and pressure drop per cubic meter obtained from oil wells under different well opening pressures, a fitting process is performed to obtain a mathematical model in which the well opening pressure, daily fluid production, and pressure drop per cubic meter satisfy a preset functional relationship.

[0051] More specifically, the mathematical model is as follows:

[0052] ΔP=a×p b ×V c

[0053] Where ΔP is the pressure drop per cubic meter at the wellhead for every cubic meter of fluid produced; p is the well opening pressure; V is the daily fluid production; and a, b, and c are correction coefficients to be fitted.

[0054] The pressure drop value ΔP per cubic meter ranges from 0.0016 to 0.003 MPa.

[0055] Daily production fluid V and oil pressure P at the wellhead t The relationship is:

[0056] In the formula, m and n are dimensionless coefficients related to the nozzle opening, and their values ​​are determined based on a lookup table method: when the nozzle opening is 3mm, m = 12.822, n = 0.6918; when the nozzle opening is 3.5mm, m = 18.619, n = 0.6766; when the nozzle opening is 4.0mm, m = 39.859, n = 0.4792; when the nozzle opening is 4.5mm, m = 56.245, n = 0.4314; when the nozzle opening is 5mm, m = 78.343, n = 0.3784; when the nozzle opening is 5.5mm, m = 113.845, n = 0.3329; when the nozzle opening is 6mm, m = 145.639, n = 0.2834.

[0057] Figure 2a , Figure 2b and Figure 2c The fitted models for oil wells No. 1 to No. 3 in this application are illustrated.

[0058] S3, Based on the pressure drop mathematical model, the first curve showing the relationship between daily liquid production and pressure drop per cubic meter is obtained;

[0059] Specifically, in the first curve, the daily liquid production increases as the pressure drop per cubic meter increases, such as... Figure 3 The rising curve in the figure illustrates this.

[0060] S4. Measure the limit self-flowing fluid production under different well opening pressures. Based on the limit self-flowing fluid production, daily fluid production and pressure drop per cubic meter under different well opening pressures, obtain the second curve of the limit self-flowing fluid production and pressure drop per cubic meter under different well opening pressures.

[0061] Specifically, in the second curve, keeping the wellhead pressure constant, the limiting self-flowing fluid production decreases as the pressure drop per cubic meter increases. Figure 3 The diagram illustrates four descending curves.

[0062] S5. Based on the first curve and the second curve, determine the range of daily fluid production of the oil well.

[0063] Specifically, the lower limit of daily fluid production is determined based on the intersection of the second curve and the first curve at the preset lowest well opening pressure; and the upper limit of daily fluid production is determined based on the intersection of the second curve and the first curve at the preset highest well opening pressure.

[0064] The reasonable range for daily fluid production during the fracture diversion stage lies between the lower and upper limits.

[0065] After determining the range of daily fluid production of the oil well, this application controls the oil pressure by adjusting the nozzle opening, thereby adjusting the daily fluid production to keep the daily fluid production value within the aforementioned determined range, i.e., a reasonable daily fluid production.

[0066] The above-mentioned invention application scheme obtains the daily fluid production and pressure drop per cubic meter of oil well under different well opening pressures, then establishes a pressure drop mathematical model, and then obtains a first curve showing the relationship between daily fluid production and pressure drop per cubic meter based on the pressure drop mathematical model; and measures the limit self-flowing fluid production under different well opening pressures, and obtains a second curve showing the limit self-flowing fluid production and pressure drop per cubic meter under different well opening pressures based on the limit self-flowing fluid production, daily fluid production and pressure drop per cubic meter of oil well under different well opening pressures, and determines the range of daily fluid production of oil well based on the first curve and the second curve, thereby clarifying a reasonable daily fluid production and ensuring long-term stable production of oil well while taking into account a certain flowback rate.

[0067] In this embodiment of the application, a device for determining the reasonable fluid volume during the fracture conduction stage of a sandstone reservoir is also provided. The device includes:

[0068] The measurement module is used to obtain the daily fluid production and pressure drop per cubic meter of oil well under different well opening pressures;

[0069] The model fitting module is used to establish a pressure drop mathematical model based on the daily fluid production and pressure drop per cubic meter under the obtained different well opening pressures.

[0070] The first curve calculation module is used to obtain the first curve relating the daily liquid production to the pressure drop value per cubic meter based on the pressure drop mathematical model.

[0071] The second curve calculation module is used to measure the ultimate self-flowing fluid production under different well opening pressures. Based on the ultimate self-flowing fluid production, daily fluid production and pressure drop per cubic meter under different well opening pressures, the second curve of the ultimate self-flowing fluid production and pressure drop per cubic meter under different well opening pressures is obtained.

[0072] The range calculation module is used to determine the range of daily fluid production of the oil well based on the first curve and the second curve.

[0073] In another aspect of the embodiments of this application, a computer storage medium is also provided.

[0074] This application also provides a computer-readable storage medium, which includes a stored program, wherein the program, when running, controls the device where the storage medium is located to execute the above-described method. The specific implementation process will not be repeated here.

[0075] This application also provides a computer device. The computer device of this embodiment includes: a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the methods described above in the embodiment; to avoid repetition, these will not be elaborated further here. Alternatively, when the computer program is executed by the processor, it implements the functions of each model / unit in the device of the embodiment; to avoid repetition, these will not be elaborated further here.

[0076] Computer equipment can be desktop computers, laptops, handheld computers, servers, and cloud servers, etc. Computer equipment may include, but is not limited to, processors and memory. Those skilled in the art will understand that it may include more or fewer components than illustrated, or combine certain components, or different components; for example, computer equipment may also include input / output devices, network access devices, buses, etc.

[0077] The processor referred to can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor.

[0078] Memory can be an internal storage unit of a computer device, such as a hard drive or RAM. Memory can also be an external storage device of a computer device, such as a plug-in hard drive, Smart Media Card (SMC), Secure Digital (SD) card, or Flash Card. Furthermore, memory can include both internal and external storage units. Memory is used to store computer programs and other programs and data required by the computer device. Memory can also be used to temporarily store data that has been output or will be output.

[0079] 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.

[0080] In the embodiments provided by this invention, 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 the units described above 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 coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection between devices or units through some interfaces, and may be electrical, mechanical, or other forms.

[0081] The integrated units implemented as software functional units described above can be stored in a computer-readable storage medium. These software functional units, stored in a storage medium, include several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to execute some steps of the methods described in the various embodiments of the present invention. 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.

[0082] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for determining the appropriate fluid volume during the fracture conduction stage of a sandstone reservoir, characterized in that, The method includes: Obtaining the daily fluid production and pressure drop per cubic meter of an oil well under different well opening pressures includes: obtaining the daily fluid production of the oil well through a flow meter installed at the wellhead; obtaining the oil pressure at the wellhead in real time through a pressure gauge installed at the wellhead, and obtaining the well opening pressure and the pressure drop per cubic meter at the wellhead for each cubic meter of fluid produced based on the real-time oil pressure. Based on the obtained daily fluid production and pressure drop per cubic meter under different well opening pressures, a pressure drop mathematical model is established, including: fitting the obtained data of daily fluid production and pressure drop per cubic meter of oil wells under different well opening pressures to obtain a mathematical model in which the well opening pressure, daily fluid production, and pressure drop per cubic meter satisfy a preset functional relationship. The mathematical model of the preset functional relationship is as follows: in, This refers to the pressure drop per cubic meter at the wellhead for every cubic meter of fluid extracted. For well opening pressure; Daily liquid production; , and These are the correction coefficients to be fitted; Among them, the pressure drop value per cubic meter The numerical range is between 0.0016 and 0.003 MPa; Daily liquid production Oil pressure at the wellhead P t The relationship is: In the formula, m、n This is a dimensionless coefficient related to the nozzle opening. The value is determined using a lookup table method: when the nozzle opening is 3mm, m=12.822, n=0.6918; when the nozzle opening is 3.5mm, m=18.619, n=0.6766; when the nozzle opening is 4.0mm, m=39.859, n=0.4792; when the nozzle opening is 4.5mm, m=56.245, n=0.4314; when the nozzle opening is 5mm, m=78.343, n=0.3784; when the nozzle opening is 5.5mm, m=113.845, n=0.3329; when the nozzle opening is 6mm, m=145.639, n=0.2834. Based on the pressure drop mathematical model, the first curve showing the relationship between daily liquid production and pressure drop per cubic meter is obtained; The limiting self-flowing fluid production rate under different well opening pressures was measured. Based on the limiting self-flowing fluid production rate, daily fluid production rate, and pressure drop per cubic meter under different well opening pressures, a second curve of the limiting self-flowing fluid production rate and pressure drop per cubic meter under different well opening pressures was obtained. In the second curve, keeping the well opening pressure constant, the limiting self-flowing fluid production rate decreases as the pressure drop per cubic meter increases. Based on the first curve and the second curve, the range of daily fluid production of the oil well is determined, including: determining the lower limit of daily fluid production based on the intersection of the second curve and the first curve at the preset lowest well opening pressure; and determining the upper limit of daily fluid production based on the intersection of the second curve and the first curve at the preset highest well opening pressure. After determining the range of daily fluid production of the oil well, the determination method further includes: The oil pressure is controlled by adjusting the opening of the oil nozzle, thereby regulating the daily liquid production and keeping the daily liquid production value within a certain range.

2. The method for determining the reasonable fluid volume during the fracture conduction stage of sandstone reservoirs according to claim 1, characterized in that, In the first curve, the daily liquid production increases as the pressure drop per cubic meter increases.

3. A device for determining the appropriate fluid volume during the fracture conduction stage of a sandstone reservoir, used to implement the method for determining the appropriate fluid volume during the fracture conduction stage of a sandstone reservoir as described in claim 1 or 2, characterized in that, The device includes: The measurement module is used to obtain the daily fluid production and pressure drop per cubic meter of oil well under different well opening pressures; The model fitting module is used to establish a pressure drop mathematical model based on the daily fluid production and pressure drop per cubic meter under the obtained different well opening pressures. The first curve calculation module is used to obtain the first curve relating the daily liquid production to the pressure drop value per cubic meter based on the pressure drop mathematical model. The second curve calculation module is used to measure the ultimate self-flowing fluid production under different well opening pressures. Based on the ultimate self-flowing fluid production, daily fluid production and pressure drop per cubic meter under different well opening pressures, the second curve of the ultimate self-flowing fluid production and pressure drop per cubic meter under different well opening pressures is obtained. The range calculation module is used to determine the range of daily fluid production of the oil well based on the first curve and the second curve.

4. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, which, when executed, controls the device containing the computer-readable storage medium to perform the method for determining the reasonable fluid volume during the fracture diversion stage of sandstone reservoirs as described in any one of claims 1 to 2.

5. A computer device, characterized in that, It includes a processor and a memory; the memory stores a computer program; the processor runs the computer program to control the computer device to execute the method for determining the reasonable fluid volume in the fracture diversion stage of sandstone reservoirs as described in any one of claims 1 to 2.

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