Optimal selection method for fracturing perforation section of coal bed gas horizontal well

Abstract

The invention discloses a coal bed gas horizontal well fracturing perforation section optimization method. The method comprises the steps that reservoir physical property parameters, a coal bed typical logging curve, well basic data, well track data, production casing data, drilling time data, gas logging data and while-drilling gamma data of coal bed gas are collected; establishing a dual-porosity model according to the reservoir physical property parameters and the borehole trajectory data, predicting the yields and costs of different fracturing segment numbers based on the dual-porosity model, and determining the optimal fracturing segment number; processing the well track data, the production casing data, the drilling time data, the gas logging data and the while-drilling gamma data to generate a comprehensive index of a fracturing perforation point; and determining an optimal perforation point according to the optimal fracturing section number, the comprehensive index, the safety distance between the fracturing perforation section and the middle completion point, and the safety distance between the fracturing perforation section and the artificial well bottom. According to the scheme, the fracturing success rate of the coal seam horizontal well can be increased, and the fracturing transformation cost is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of coalbed methane horizontal well development, and in particular to a coalbed methane horizontal well fracturing perforation section optimization method, computing equipment and storage medium. Background Art

[0002] my country has abundant coalbed methane resources with broad prospects for development and application. However, my country's coalbed methane reservoirs generally have low porosity and low permeability characteristics, and are often distributed in multiple layers with complex geological structures. The coal type, thickness, maturity, etc. of different layers vary greatly. In order to improve the production capacity of coalbed methane wells, it is necessary to increase the production of coalbed methane production wells.

[0003] Horizontal well technology and surface fracturing technology are two key technologies for coalbed methane development and production increase. In recent years, single horizontal well staged fracturing technology has gradually become the mainstream means of increasing the production of coalbed methane horizontal wells. After high-pressure fluid is injected into the coal reservoir, it can not only open natural fractures, but also form new artificial fractures. These fracturing fractures are interconnected to form a complex fracture network, which can improve the effective permeability of the coalbed methane reservoir, reduce the seepage resistance of the fluid, increase the gas production channel of the coalbed methane, and ultimately achieve high and stable production of coalbed methane wells.

[0004] During the drilling process, the horizontal section of the coalbed methane well is affected by the heterogeneity, structural characteristics, pore structure, etc. of the coal seam. It is often difficult to achieve a complete drilling in the middle of the coal seam, and it is difficult to achieve a 100% drilling rate. If the fracturing perforation section is not selected properly, it is very easy to cause problems such as failure to open the reservoir, sand plugging, and fracture extension not meeting expectations. This requires the optimization of the fracturing perforation section during coalbed methane fracturing to ensure smooth fracturing construction.

[0005] The optimization of perforation sections is mainly reflected in the number of fracturing sections and the location of fracturing perforations. As the number of fracturing sections increases, the flow rate into the horizontal well through the fractures increases, the interference between the fractures increases, resulting in a decrease in the fracture spacing, which reduces the increase in horizontal well production. Therefore, the optimal number of fracturing sections should be determined by comprehensively considering the cost and fracture production increase benefits. While determining the number of fracturing sections, it is also necessary to consider the perforation location of each fracturing section to ensure that the fractures effectively extend to the target layer. Summary of the invention

[0006] In order to improve the success rate of fracturing and the effect of fracturing transformation, this program proposes a method for optimizing the fracturing perforation section of coalbed methane horizontal wells. By combining multi-source data for comprehensive analysis, it can improve the understanding and prediction of underground reservoir characteristics, and by establishing a dual-porosity numerical simulation model to predict the production capacity of horizontal wells with different fracturing sections, it can make more comprehensive and objective fracturing optimization decisions for horizontal wells. By establishing a comprehensive index calculation model and a method for determining the optimal number of fracturing sections, data-driven decision-making is made more scientific.

[0007] According to a first aspect of the present invention, a method for optimizing the fracturing and perforating sections of a coalbed methane horizontal well is provided, comprising: collecting reservoir physical property parameters of coalbed methane, typical well logging curves of coalbeds, well basic data, wellbore trajectory data, production casing data, drilling time data, gas logging data and gamma data while drilling; A dual-porosity model is established based on reservoir physical parameters and well trajectory data, and the production and cost of different fracturing stages are predicted based on the dual-porosity model to determine the optimal number of fracturing stages; Process well trajectory data, production casing data, drilling time data, gas logging data and gamma data while drilling to generate a comprehensive index of fracturing perforation points; The preferred perforation points are determined based on the optimal number of fracturing stages, comprehensive index, safe distance between the fracturing perforation section and the mid-completion point, and safe distance between the fracturing perforation section and the bottom of the artificial well.

[0008] Optionally, in the coalbed methane horizontal well fracturing and perforation section optimization method provided by the present invention, the reservoir physical property parameters include gas content, gas adsorption parameters, pore structure parameters, formation physical property parameters, and coal seam thickness; typical coal seam logging curves include natural gamma logging curves, resistivity logging curves, sonic logging curves, neutron logging curves, and density logging curves; well basic data include well location coordinates, horizontal section length, mid-completion point depth, and completion point depth; wellbore trajectory data include well depth, well inclination, azimuth, vertical depth, north-south coordinates, and east-west coordinates; production casing data include down depth, coupling position, resistance position, casing diameter, and wall thickness.

[0009] Optionally, in the coalbed methane horizontal well fracturing and perforation section optimization method provided by the present invention, a dual-porosity model is established using numerical simulation software based on reservoir physical properties and wellbore trajectory data; different fracturing stages are set to simulate and predict the production of different fracturing stages; the unit gas production cost corresponding to each fracturing stage is calculated based on the total fracturing cost and the predicted production; and the optimal number of fracturing stages is determined based on the unit gas production cost.

[0010] Optionally, in the method for optimizing the fracturing and perforating sections of coalbed methane horizontal wells provided by the present invention, the wellbore trajectory data is processed according to typical logging curves of the coal seam and gamma data while drilling, and the distance between the wellbore trajectory and the coal seam is calculated; the distance between the wellbore trajectory and the coal seam, drilling time data, gas logging data, and gamma data while drilling are processed to generate a comprehensive index as a basis for optimizing the fracturing and perforating points.

[0011] Optionally, in the coalbed methane horizontal well fracturing perforation section optimization method provided by the present invention, when the gamma value while drilling is greater than the maximum gamma value of the target coal seam, a=0, otherwise the value is taken according to the following formula: a=(GRmax-GR) / (GRmax-GRmin) Among them, a is the gamma coefficient, GR is the gamma value of the target point, GRmin is the minimum gamma value of the coal seam, and GRmax is the maximum gamma value of the coal seam; When the drilling time value is less than the drilling time value of the coal seam in the block, b = 1, otherwise b = 0, and b is the drilling time coefficient; The gas logging value is taken as c = (TG - TGmin) / (TGmax - TGmin) Among them, c is the gas logging coefficient, TG is the gas logging value of the target point, TGmin is the minimum gas logging value of the horizontal section, and TGmax is the maximum gas logging value of the horizontal section; When the distance from the casing collar is less than the allowable safety distance, e = 0, otherwise e = 1, and e is the safety coefficient; Calculate the comprehensive index of the fracturing perforation section: k = a * b * c * e, and k is the comprehensive index.

[0012] Optionally, in the method for optimizing the fracturing perforation section of a coalbed methane horizontal well provided by the present invention, by comparing the changes in the logging curve values of different depth sections in the typical logging curve of the coal seam, identify the boundaries of the roof, floor, and parting of the coal seam, and determine the number of partings and the gamma value range of the target coal seam; Compare the gamma data while drilling with the typical logging curve of the coal seam, correct the gamma value range of the parting in the target coal seam, and determine the positions of the wellbore trajectories of the roof, floor, and parting of the coal seam; Combined with the trend changes of the upper and lower gamma values and the logging data, calculate the distances between the wellbore trajectory and the roof and floor of the coal seam, and calculate the well elevation, roof elevation, and floor elevation. The well elevation is equal to the wellhead elevation minus the well vertical depth, the roof elevation is equal to the well elevation plus the distance to the roof, and the floor elevation is equal to the well elevation plus the distance to the roof minus the coal seam thickness.

[0013] Optionally, in the method for optimizing the fracturing perforation section of a coalbed methane horizontal well provided by the present invention, the principle for selecting the fracturing perforation points is 0 < k <= 1, where the closer k is to 1, the higher the preference level. Select the preferred perforation points that meet the safety distance requirements in the order from high to low preference level. The safety distances include the safety distance between the fracturing perforation section and the intermediate completion point, and the safety distance between the fracturing perforation section and the artificial bottom hole; Output the well depth, elevation, drilling time, gamma, total hydrocarbon, position of the male collar, distance from the male collar, position of the female collar, distance from the female collar, and comprehensive index corresponding to each preferred perforation point; generate a corresponding relationship diagram of the comprehensive index of the preferred perforation points.

[0014] Optionally, in the method for optimizing the fracturing perforation section of a coalbed methane horizontal well provided by the present invention, generate a comprehensive analysis diagram based on the processed wellbore trajectory data, drilling time data, gas logging data, and gamma data while drilling; automatically plot the preferred perforation points into the comprehensive analysis diagram.

[0015] According to a second aspect of the present invention, there is provided a computing device comprising: at least one processor; and a memory storing program instructions, wherein the program instructions are configured to be suitable for execution by at least one processor, and the program instructions include instructions for executing the above-mentioned coalbed methane horizontal well fracturing perforation section optimization method.

[0016] According to a third aspect of the present invention, a readable storage medium storing program instructions is provided. When the program instructions are read and executed by a computing device, the computing device executes the above-mentioned coalbed methane horizontal well fracturing perforation section optimization method.

[0017] According to the method for optimizing the fracturing and perforating sections of coalbed methane horizontal wells provided by the present invention, a more comprehensive basis can be provided for subsequent decision-making by fully integrating multiple data sources; by establishing a dual-porosity model, the physical properties of the coalbed methane reservoir can be more accurately described, which is helpful to predict the production and cost of different fracturing sections and achieve a balance between production benefits and costs; by generating a comprehensive index of the fracturing and perforating sections, the changes in various parameters can be more comprehensively evaluated, and the optimal number of fracturing sections and the comprehensive index of the perforating sections can be combined to determine the preferred perforating points according to the preset selection principles, which is helpful to improve the success rate and efficiency of coalbed methane extraction.

[0018] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings: Figure 1 A block diagram of a computing device 100 according to an embodiment of the present invention is shown; Figure 2 A schematic flow chart of a method 200 for optimizing a coalbed methane horizontal well fracturing and perforating section according to an embodiment of the present invention is shown; Figure 3 A schematic diagram of a data representation of a preferred result of a fracturing perforation section according to an embodiment of the present invention is shown; Figure 4 A schematic diagram showing a corresponding relationship between preferred comprehensive indexes for fracturing and perforating sections according to an embodiment of the present invention is shown; Figure 5 A schematic diagram of comprehensive analysis of a preferred fracturing perforation section according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0020] In order to optimize the fracturing and perforating sections of coalbed methane horizontal wells, the geological conditions of the coal seams are usually analyzed in detail, the directional drilling technology is used to improve the drilling rate, the coal seams are imaged using seismic exploration data to identify the internal structure of the coal seams, and different fracturing and perforating section schemes are simulated and analyzed with the help of numerical simulation software to evaluate the impact of various factors on the fracturing effect, so as to optimize the selection of fracturing and perforating sections. Conventional optimization schemes fail to effectively balance costs and benefits, and cannot effectively cope with the prediction uncertainty of the complex and changing underground environment.

[0021] In order to solve this technical defect, this program proposes a method for optimizing the fracturing and perforation sections of coalbed methane horizontal wells. By combining multi-source data for comprehensive analysis, it can improve the understanding and prediction capabilities of underground reservoir characteristics, and by establishing a dual-porosity numerical simulation model to predict the production capacity of horizontal wells with different fracturing sections, it can make more comprehensive and objective decisions on the optimization of fracturing of horizontal wells. By establishing a comprehensive index calculation model and a method for determining the optimal number of fracturing sections, data-driven decisions are made more scientific.

[0022] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0023] Figure 1 FIG. 1 shows a block diagram of a computing device 100 according to an embodiment of the present invention. Figure 1 As shown, in a basic configuration 102, computing device 100 typically includes memory 106 and one or more processors 104. A memory bus 108 may be used for communication between processor 104 and memory 106.

[0024] The processor 104 may be any type of processor, including but not limited to a microprocessor (µP), a microcontroller (µC), a digital signal processor (DSP), or any combination thereof. The processor 104 may include one or more levels of cache, such as a level 1 cache 110 and a level 2 cache 112, a processor core 114, and registers 116. An example processor core 114 may include an arithmetic logic unit (ALU), a floating point unit (FPU), a digital signal processing core (DSP core), or any combination thereof. An example memory controller 118 may be used with the processor 104, or in some implementations, the memory controller 118 may be an internal part of the processor 104.

[0025] The memory 106 may be any type of memory, including but not limited to: volatile memory (such as RAM), non-volatile memory (such as ROM, flash memory, etc.), or any combination thereof. The physical memory in a computing device generally refers to the volatile memory RAM, and the data in the disk needs to be loaded into the physical memory before it can be read by the processor 104. The system memory 106 may include an operating system 120, one or more applications 122, and program data 124.

[0026] In some embodiments, the application 122 may be arranged to execute instructions on an operating system by one or more processors 104 using program data 124. The operating system 120 may be, for example, Linux, Windows, etc., which includes program instructions for processing basic system services and performing hardware-dependent tasks. The application 122 includes program instructions for implementing various user-desired functions, and the application 122 may be, for example, a browser, instant messaging software, a software development tool (e.g., an integrated development environment IDE, a compiler, etc.), etc., but is not limited thereto. When the application 122 is installed in the computing device 100, a driver module may be added to the operating system 120.

[0027] When the computing device 100 starts running, the processor 104 reads and executes the program instructions of the operating system 120 from the memory 106. The application 122 runs on the operating system 120 and uses the interfaces provided by the operating system 120 and the underlying hardware to implement various functions desired by the user. When the user starts the application 122, the application 122 is loaded into the memory 106, and the processor 104 reads and executes the program instructions of the application 122 from the memory 106.

[0028] Computing device 100 also includes a storage device 132 including a removable storage 136 and a non-removable storage 138 , both of which are connected to storage interface bus 134 .

[0029] The computing device 100 may also include an interface bus 140 that facilitates communication from various interface devices (e.g., output devices 142, peripheral interfaces 144, and communication devices 146) to the basic configuration 102 via the bus / interface controller 130. Example output devices 142 include a graphics processing unit 148 and an audio processing unit 150. They can be configured to facilitate communication with various external devices such as a display or speakers via one or more A / V ports 152. Example peripheral interfaces 144 may include a serial interface controller 154 and a parallel interface controller 156, which may be configured to facilitate communication with external devices such as input devices (e.g., keyboards, mice, pens, voice input devices, touch input devices) or other peripherals (e.g., printers, scanners, etc.) via one or more I / O ports 158. Example communication devices 146 may include a network controller 160, which may be arranged to facilitate communication with one or more other computing devices 162 via a network communication link via one or more communication ports 164.

[0030] A network communication link can be an example of a communication medium. Communication media can generally be embodied as computer-readable instructions, data structures, program modules in a modulated data signal such as a carrier wave or other transmission mechanism, and can include any information delivery medium. A "modulated data signal" can be a signal in which one or more of its data sets or its changes can be performed in a manner that encodes information in the signal. As a non-limiting example, communication media can include wired media such as a wired network or a dedicated network, and various wireless media such as sound, radio frequency (RF), microwave, infrared (IR) or other wireless media. The term computer-readable media used here can include both storage media and communication media. In a computing device 100 according to the present invention, the application 122 includes instructions for executing the coalbed methane horizontal well fracturing perforation section optimization method 200 of the present invention.

[0031] Figure 2 FIG. 2 is a flow chart showing a method 200 for optimizing a fracturing and perforating section of a coalbed methane horizontal well according to an embodiment of the present invention. Figure 2 As shown, the method starts with step S210, collecting reservoir physical property parameters of coalbed methane, typical logging curves of coal seams, well basic data, wellbore trajectory data, production casing data, drilling time data, gas logging data and while drilling gamma data.

[0032] In order to carry out geological modeling, reservoir numerical simulation, production capacity evaluation and other tasks, reservoir parameters including gas content, gas adsorption parameters (Raman volume, Raman pressure), reservoir physical properties (porosity, permeability, density, comprehensive compression coefficient, etc.), fluid attribute parameters (density, viscosity, original formation pressure, etc.), reservoir temperature, coal seam thickness, coal seam depth and other data can be collected. These parameters are crucial for evaluating the recoverable reserves and production potential of the reservoir.

[0033] Typical logging curves of coal seams may include natural gamma logging curves, resistivity logging curves, sonic logging curves, neutron logging curves, density logging curves, and the like.

[0034] For example, the natural gamma logging curve is used to identify and describe the lithology and mineralization of the formation, which is of great significance for determining the thickness and boundary of the coal seam. The resistivity logging curve can be used to identify the porosity and water saturation of the reservoir, and has a certain effect on evaluating the permeability and other parameters of the coal seam. The sonic logging curve can provide velocity information of the formation, which is helpful for the lithology identification and formation parameter evaluation of the coal seam. The neutron logging curve can provide hydrogen content information of the formation, which is of certain significance for identifying parameters such as coalbed methane saturation and water saturation. The density logging curve provides density information of the formation, which can be used to evaluate the porosity, mineral content and other parameters of the formation.

[0035] Well basic data include basic information and related parameters of the well, including well location coordinates (wellhead coordinates and ground elevation), horizontal section length, well depth at the middle completion point, well depth at the completion point, etc. The well depths at the middle completion point and the completion point reflect the progress of the horizontal well section. These data can be obtained through measurement and recording and used to evaluate the geological characteristics, structure and reserve potential of coalbed methane reservoirs.

[0036] The wellbore trajectory data may include the well depth, well inclination, azimuth, vertical depth, north-south coordinates and east-west coordinates expressed in a Cartesian coordinate system recorded during the drilling process. By analyzing the wellbore trajectory data, the position, direction and strike of the wellbore during the drilling process can be understood, thereby evaluating the distribution of oil and gas layers and locating the target formation.

[0037] Production casing data may include depth (the installation depth of the production casing in the wellbore), collar position (the position of the support collar set on the production casing), resistance (a special structure designed at the lower end of the casing to prevent the reverse flow of the annular fluid), diameter and wall thickness of the casing, and other dimensional parameters. Accurate measurement and control of these parameters are crucial to the safe and efficient operation of the oil well production system.

[0038] Drilling time data (drilling speed), gas logging data (total hydrocarbon content percentage, component content percentage), and while-drilling gamma data (gamma-ray data) are used to monitor the formation conditions during the drilling process, identify potential geological risks, and guide drilling operations.

[0039] The collection and analysis of the above data will help to better understand the characteristics of coalbed methane reservoirs, geological conditions and downhole environment, guide subsequent drilling, completion and production operations, improve exploration and development efficiency, reduce risks, and ultimately achieve the effective development and utilization of coalbed methane resources.

[0040] Then, step S220 is executed to establish a dual-porosity model according to reservoir physical property parameters and wellbore trajectory data, and to predict the production and cost of different fracturing stages based on the dual-porosity model to determine the optimal number of fracturing stages.

[0041] The dual-porosity model refers to a geological model used to simulate reservoir media with two different porosities, for example, combining microscopic pores and fracture pores, considering the interaction between pores, and performing superposition or coupling to obtain the overall porosity distribution.

[0042] In one embodiment of the present invention, the collected data may be first cleaned to ensure the accuracy and consistency of the data. Then, a dual porosity model may be established based on the reservoir physical parameters and the wellbore trajectory data using numerical modeling software (such as Eclipse, CMG, etc.) to predict the production capacity of the target well. The model geometry may be established based on the wellbore trajectory data, including simulated wellbore, formation structure, and porosity distribution.

[0043] Set different fracturing stages and use numerical simulation software to simulate and analyze the production of different fracturing stages. Calculate the unit gas production cost corresponding to each fracturing stage based on the total fracturing cost and the predicted production, that is: J=M / Q J is the unit gas production cost, in yuan / m³, M is the total fracturing cost, in yuan, and Q is the predicted cumulative gas production during the project period, in m³.

[0044] Finally, the optimal number of fracturing stages is determined based on the unit gas production cost. For example, the unit gas production costs corresponding to each fracturing stage are compared to find the number of fracturing stages with the lowest unit gas production cost. Generally speaking, the lower the unit gas production cost, the lower the cost per unit of gas production, and the better the economic benefits. In addition to the unit gas production cost, it is also necessary to comprehensively evaluate the plans for different fracturing stages in combination with the production capacity forecast results, and select the fracturing stage plan that is both economical and can increase production capacity as the best option.

[0045] Then, step S230 is executed to process the wellbore trajectory data, production casing data, drilling time data, gas logging data and while-drilling gamma data to generate a comprehensive index of the fracturing perforation points.

[0046] Firstly, the borehole trajectory data is processed according to the typical logging curve of the coal seam and the gamma data while drilling, and the distance between the borehole trajectory and the coal seam is calculated.

[0047] Specifically, by comparing the changes in logging values ​​at different depths in typical logging curves, the boundaries of the coal seam roof, floor and interlayers are identified, and the number of interlayers and the gamma value range of the target coal seam are determined.

[0048] Compare the gamma data while drilling with the typical logging curve of the coal seam, correct the gamma value range of the target coal seam with gangue, and determine the position of the coal seam roof, floor and gangue borehole trajectory. Combine the trend change of the upper and lower gamma values ​​and the logging data to calculate the distance between the borehole trajectory and the coal seam roof and floor, and calculate the parameters such as the well altitude, roof altitude and floor altitude based on the calculated distance between the borehole trajectory and the coal seam roof and floor.

[0049] Among them, well altitude = wellhead elevation - well vertical depth, roof altitude = well altitude + distance from roof, bottom plate altitude = well altitude + distance from roof - coal seam thickness.

[0050] Then, the distance between the wellbore trajectory and the coal seam, drilling time data, gas logging data, and gamma data while drilling are processed to generate a comprehensive index as a basis for optimizing the fracturing perforation points.

[0051] For example, when the gamma value while drilling is greater than the maximum gamma value of the target coal seam, a=0, otherwise it is taken according to the following formula: a=(GRmax-GR) / (GRmax-GRmin) Among them, a is the gamma coefficient, GR is the gamma value of the target point, GRmin is the minimum gamma value of the coal seam, and GRmax is the maximum gamma value of the coal seam; When the drilling time value is less than the block coal seam drilling time value, b=1, otherwise b=0, b is the drilling time coefficient; The gas measurement value is c= (TG-TGmin) / (TGmax-TGmin) Wherein, c is the gas measurement coefficient, TG is the gas measurement value of the target point, TGmin is the minimum gas measurement value of the horizontal section, and TGmax is the maximum gas measurement value of the horizontal section; When the distance from the casing coupling is less than the allowed safety distance, e=0, otherwise e=1, where e is the safety factor.

[0052] After processing the drilling data, gas logging data, production casing data, and gamma data while drilling, the comprehensive index of the fracturing and perforating section is calculated: k=a*b*c*e, where k is the comprehensive index. The comprehensive index is used as the basis for the optimal selection of the fracturing and perforating section.

[0053] Finally, step S240 is executed to determine the preferred perforation points based on the optimal number of fracturing stages, the comprehensive index, the safety distance between the fracturing perforation section and the mid-perforation point, and the safety distance between the fracturing perforation section and the artificial bottom hole.

[0054] First, it can be determined that the principle for selecting fracturing perforation points is 0 < k <= 1, and the closer k is to 1, the higher the preference level. Select the preferred perforation points that meet the safety distance requirements in the order from the highest to the lowest preference level, and the number of preferred perforation points is the optimal number of fracturing perforation points.

[0055] The mid-perforation point is the last perforation point used in the hydraulic fracturing operation. Ensuring the safety distance between the fracturing perforation section and the mid-perforation point can avoid prematurely closing the fracturing operation or generating unnecessary cross-interference. Ensuring the safety distance between the fracturing perforation section and the artificial bottom hole can avoid damaging or interfering with the existing wellbore and production equipment.

[0056] Finally, output the well depth, elevation, drilling time, gamma, total hydrocarbon, position of male coupling, distance from male coupling, position of female coupling, distance from female coupling, and comprehensive index corresponding to each preferred perforation point, and generate a corresponding relationship diagram of the comprehensive index of the preferred perforation points.

[0057] Figure 3 Shows a schematic diagram of the preferred result data of the fracturing perforation section according to an embodiment of the present invention. As Figure 3 shown, the data such as well depth, gamma, drilling time, total hydrocarbon, position of male coupling, distance from male coupling, position of female coupling, distance from female coupling, and comprehensive index corresponding to each preferred perforation point can be output in the order from the highest to the lowest preference level of the comprehensive index.

[0058] Figure 4 Shows a schematic diagram of the corresponding relationship of the comprehensive index of the preferred fracturing perforation section according to an embodiment of the present invention. As Figure 4 shown, the closer the comprehensive index is to 1, the higher the preference level. Plotting the comprehensive index of each perforation point into a chart can visually display the advantages and disadvantages of different perforation points.

[0059] It is also possible to generate a comprehensive analysis diagram based on the processed wellbore trajectory data, drilling time data, gas logging data, and gamma data while drilling, and automatically plot the preferred perforation points into the comprehensive analysis diagram.

[0060] Figure 5 Shows a schematic diagram of the comprehensive analysis of the preferred fracturing perforation section according to an embodiment of the present invention. As Figure 5 shown, in the comprehensive analysis diagram, the changes of various parameters such as drilling time data, wellbore trajectory data, total hydrocarbon data, and gamma data can be displayed. According to the position information of the fracturing points, they are automatically plotted in the comprehensive analysis diagram and marked within the curve to facilitate visually viewing the changes of various parameters near the selected fracturing perforation points.

[0061] The method for optimizing the fracturing and perforating sections of coalbed methane horizontal wells provided by the present invention can provide a more comprehensive basis for subsequent decision-making by fully integrating multiple data sources. By establishing a dual-porosity model, it can more accurately describe the physical properties of the coalbed methane reservoir, which is helpful to predict the output and cost of different fracturing sections and achieve a balance between production benefits and costs. By generating a comprehensive index of the fracturing and perforating sections, the changes in various parameters can be more comprehensively evaluated. Combined with the optimal number of fracturing sections and the comprehensive index of the perforating sections, the preferred perforating points can be determined according to the preset selection principles, which helps to improve the success rate and efficiency of coalbed methane extraction.

[0062] In the description provided herein, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.

[0063] Those skilled in the art will appreciate that the modules or units or components of the devices in the examples disclosed herein may be arranged in the devices described in the embodiment, or alternatively may be located in one or more devices different from the devices in the examples. The modules in the foregoing examples may be combined into one module or may be divided into multiple submodules.

[0064] Those skilled in the art will appreciate that the modules in the devices in the embodiments may be adaptively changed and arranged in one or more devices different from the embodiments. The modules or units or components in the embodiments may be combined into one module or unit or component, and furthermore may be divided into a plurality of submodules or subunits or subcomponents.

[0065] Furthermore, those skilled in the art will appreciate that although some embodiments described herein include certain features included in other embodiments but not other features, the combination of features from different embodiments is meant to be within the scope of the present invention and to form different embodiments.

[0066] As used herein, unless otherwise specified, the use of ordinal numbers "first," "second," "third," etc. to describe common objects merely indicates that different instances of similar objects are involved, and is not intended to imply that the objects so described must have a given order in time, space, order, or in any other manner.

[0067] Although the present invention has been described according to a limited number of embodiments, it will be apparent to those skilled in the art, with the benefit of the above description, that other embodiments may be envisioned within the scope of the invention thus described. In addition, it should be noted that the language used in this specification is selected primarily for readability and teaching purposes, rather than for explaining or defining the subject matter of the present invention. Therefore, many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the appended claims. The disclosure of the present invention is illustrative and not restrictive with respect to the scope of the present invention, and the scope of the present invention is defined by the appended claims.

Claims

1. A method for optimizing the perforation section of a coalbed methane horizontal well fracturing, characterized in that: include: Collect coalbed methane reservoir physical parameters, typical coal seam logging curves, well basic data, wellbore trajectory data, production casing data, drilling time data, gas logging data and gamma data while drilling; Establishing a dual porosity model according to the reservoir physical property parameters and wellbore trajectory data, and predicting the production and cost of different fracturing stages based on the dual porosity model to determine the optimal fracturing stage number; Processing the wellbore trajectory data, production casing data, drilling time data, gas logging data and gamma data while drilling to generate a comprehensive index of fracturing perforation points; The preferred perforation point is determined according to the optimal number of fracturing stages, the comprehensive index, the safe distance between the fracturing perforation stage and the mid-point, and the safe distance between the fracturing perforation stage and the bottom of the artificial well.

2. The method for optimizing the fracturing and perforating sections of a coalbed methane horizontal well according to claim 1, characterized in that: The reservoir physical property parameters include gas content, gas adsorption parameters, pore structure parameters, formation physical property parameters, and coal seam thickness; the typical coal seam logging curves include natural gamma logging curves, resistivity logging curves, sonic logging curves, neutron logging curves, and density logging curves; the basic well data include well location coordinates, horizontal section length, mid-completion point depth, and completion point depth; the wellbore trajectory data include well depth, well inclination, azimuth, vertical depth, north-south coordinates, and east-west coordinates; the production casing data include depth, coupling position, resistance position, casing diameter, and wall thickness.

3. The method for optimizing the perforation section of a coalbed methane horizontal well fracturing according to claim 1, characterized in that: The step of establishing a dual porosity model according to the reservoir physical property parameters and the wellbore trajectory data, and predicting the production and cost of different fracturing stages based on the dual porosity model, and determining the optimal number of fracturing stages includes: According to the reservoir physical property parameters and wellbore trajectory data, a dual porosity model is established using numerical simulation software; Set different fracturing stages and simulate and predict the production of different fracturing stages; Calculate the unit gas production cost corresponding to each fracturing stage based on the total fracturing cost and the predicted production; The optimal number of fracturing stages is determined according to the unit gas production cost.

4. The method for optimizing the perforation section of a coalbed methane horizontal well fracturing according to claim 1, characterized in that: The step of processing the wellbore trajectory data, production casing data, drilling time data, gas logging data and while-drilling gamma data to generate a comprehensive index of fracturing perforation points comprises: Processing the wellbore trajectory data according to the typical well logging curve of the coal seam and the gamma data while drilling to calculate the distance between the wellbore trajectory and the coal seam; The distance between the wellbore trajectory and the coal seam, drilling time data, gas logging data, and gamma data while drilling are processed to generate a comprehensive index as a basis for optimizing the fracturing perforation points.

5. The method for optimizing the fracturing and perforating sections of a coalbed methane horizontal well according to claim 4, characterized in that: The step of processing the distance between the wellbore trajectory and the coal seam, drilling time data, gas logging data, and gamma data while drilling to generate a comprehensive index comprises: When the gamma value while drilling is greater than the maximum gamma value of the target coal seam, a=0, otherwise it is taken according to the following formula: a=(GRmax-GR) / (GRmax-GRmin) Among them, a is the gamma coefficient, GR is the gamma value of the target point, GRmin is the minimum gamma value of the coal seam, and GRmax is the maximum gamma value of the coal seam; When the drilling time value is less than the block coal seam drilling time value, b=1, otherwise b=0, b is the drilling time coefficient; The gas measurement coefficient is c= (TG-TGmin) / (TGmax-TGmin) Among them, c is the gas logging coefficient, TG is the gas logging value at the target point, TGmin is the minimum gas logging value in the horizontal section, and TGmax is the maximum gas logging value in the horizontal section; When the distance from the casing collar is less than the allowable safety distance, e = 0, otherwise e = 1, and e is the safety coefficient; Calculate the comprehensive index of the fracturing perforation section: k = a * b * c * e, where k is the comprehensive index.

6. The method for optimizing the fracturing and perforating sections of a coalbed methane horizontal well according to claim 4, characterized in that: The step of processing the wellbore trajectory data according to the typical coal seam logging curve and the gamma data while drilling to calculate the distance between the wellbore trajectory and the coal seam includes: In the typical coal seam logging curve, by comparing the changes in the logging curve values in different depth sections, identify the boundaries of the coal seam roof, floor, and parting, and determine the number of partings in the target coal seam and the gamma value range; Compare the gamma data while drilling with the typical coal seam logging curve, correct the gamma value range of the target coal seam parting, and determine the positions of the wellbore trajectories of the coal seam roof, floor, and parting; Combined with the trend changes of the upper and lower gamma values and the logging data, calculate the distances between the wellbore trajectory and the coal seam roof and the coal seam floor, and calculate the well elevation, roof elevation, and floor elevation. The well elevation is equal to the wellhead elevation minus the well vertical depth, the roof elevation is equal to the well elevation plus the distance to the roof, and the floor elevation is equal to the well elevation plus the distance to the roof minus the coal seam thickness.

7. The method for optimizing the perforation section of a coalbed methane horizontal well fracturing according to claim 6, characterized in that: The step of determining the preferred perforation points according to the optimal number of fracturing stages, the comprehensive index, the safety distance between the fracturing perforation section and the intermediate completion point, and the safety distance between the fracturing perforation section and the artificial bottom hole includes: Determine the principle for selecting the fracturing perforation points as 0 < k <= 1, where the closer k is to 1, the higher the preferred level. Select the preferred perforation points that meet the safety distance requirements in descending order of the preferred level. The safety distance includes the safety distance between the fracturing perforation section and the intermediate completion point and the safety distance between the fracturing perforation section and the artificial bottom hole; Output the well depth, elevation, drilling time, gamma, total hydrocarbon, position of the male collar, distance from the male collar, position of the female collar, distance from the female collar, and comprehensive index corresponding to each preferred perforation point; Generate a corresponding relationship diagram of the comprehensive index of the preferred perforation points.

8. The method for optimizing the perforation section of a coalbed methane horizontal well fracturing according to claim 7, characterized in that: The method further includes: Generate a comprehensive analysis diagram according to the processed wellbore trajectory data, drilling time data, gas logging data, and gamma data while drilling; Automatically plot the preferred perforation points into the comprehensive analysis diagram.

9. A computing device, comprising: At least one processor; And a memory storing program instructions, wherein the program instructions are configured to be executed by the at least one processor, and the program instructions include instructions for executing the method for optimizing the fracturing perforation section of a coalbed methane horizontal well as described in any one of claims 1-8.

10. A readable storage medium storing program instructions, when the program instructions are read and executed by a computing device, causing the computing device to execute the method for optimizing the fracturing perforation section of a coalbed methane horizontal well as described in any one of claims 1-8.

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