Well drilling optimization method, device and equipment based on shale gas well reservoir shale drillability and medium

Abstract

The invention discloses a drilling optimization method, device, equipment and medium based on shale gas well reservoir shale drillability, and relates to the technical field of oil-gas exploration and development, the shale content of shale of a shale gas well reservoir is calculated by using logging-while-drilling information, and the shale content of the shale is obtained; determining a stratum included angle between the well trajectory of the shale and the stratum; performing numerical simulation on the well area stress field of the shale to establish a ground stress prediction plane graph of a well area target well platform and a peripheral reservoir bottom boundary, and determining a ground stress prediction value from the ground stress prediction plane graph; and drillability calculation is conducted on the shale content, the stratum included angle and the ground stress predicted value, a stratum drillability grade value is obtained, and the shale drilling process is optimized in real time through the stratum drillability grade value. According to the technical scheme, the calculation deviation of the drillability of the stratum can be reduced, the drilling time efficiency is improved, and drilling optimization based on the shale drillability of the shale gas well reservoir is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil and gas exploration and development, and particularly relates to a drilling optimization method, device, equipment and medium based on shale gas well reservoir shale drillability. BACKGROUND

[0002] In the oil and gas drilling engineering, formation drillability calculation and evaluation is one of important indexes for analyzing the mechanical drilling speed and selecting the drilling bit, and the calculation and evaluation methods include the experimental method, the drilling speed back calculation method, the DC index (formation drillability index) method, the acoustic travel time calculation method, the cutting hardness method and the like. The formation drillability is calculated by using the experimental method, the drilling speed back calculation method, the DC index method, the acoustic travel time calculation method and the cutting hardness method, which has certain limitations and time delay, and cannot ensure the accuracy and reliability of the calculation.

[0003] The determination of the drillability is based on the indoor micro-drilling experiment, but the micro-drilling experiment method has some problems due to various limitations, such as the inability to reflect the actual temperature and pressure conditions underground, the difficulty in establishing a continuous profile, the consumption of manpower and material resources, and the like. Therefore, the oil workers at home and abroad carry out research, and use the logging interpretation and the field cutting analysis to study the formation drillability. At present, the most commonly used method in the engineering is to establish the formation drillability profile by using the acoustic travel time data in the logging data. The acoustic travel time and density data in the logging data in the Hongxing work area need to be obtained by logging after each drilling is completed, and the timeliness is poor.

[0004] From the above, how to reduce the formation drillability calculation deviation, improve the drilling timeliness, and realize the drilling optimization based on the shale gas well reservoir shale drillability is a problem to be solved in the field. SUMMARY

[0005] Therefore, the purpose of the present application is to provide a drilling optimization method, device, equipment and medium based on shale gas well reservoir shale drillability, which can reduce the formation drillability calculation deviation, improve the drilling timeliness, and realize the drilling optimization based on the shale gas well reservoir shale drillability. The specific scheme is as follows:

[0006] In a first aspect, the present application discloses a drilling optimization method based on shale gas well reservoir shale drillability, comprising:

[0007] Calculating the shale content of the shale in the shale gas well reservoir by using the logging while drilling data to obtain the shale content of the shale;

[0008] Determining the formation included angle between the well trajectory of the shale and the formation;

[0009] Numerical simulation of the stress field in the well area of ​​mudstone and shale is performed to establish a geostress prediction plan of the target well platform and the bottom boundary of the surrounding reservoir in the well area, and the geostress prediction value is determined from the geostress prediction plan.

[0010] Drillability calculations are performed on the mud content, formation angle, and predicted geostress to obtain a formation drillability grade. The drilling process for mudstone and shale is then optimized in real time using the formation drillability grade.

[0011] Optionally, before calculating the clay content of the shale in the shale gas well reservoir using logging-while-drilling data, the method further includes:

[0012] Experimental analysis of influencing factors of mudstone and shale was conducted to determine the main controlling factors affecting the drillability of mudstone and shale. The main controlling factors include mud content, formation angle between well trajectory and formation, and predicted in-situ stress.

[0013] Optionally, the calculation of the clay content of the shale in the shale gas well reservoir using logging-while-drilling data includes:

[0014] The relative gamma values ​​of mudstone and shale were calculated using the measured gamma curves from the logging-while-drilling data.

[0015] The mud content of the mudstone and shale was calculated based on the gamma relative value.

[0016] Optionally, the formula for calculating the relative gamma value is:

[0017] ;

[0018] Where C is the relative gamma value, and GR is the logging-while-drilling gamma value. and These represent the maximum and minimum gamma values ​​in pure mudstone, respectively.

[0019] The formula for calculating clay content is:

[0020] ;

[0021] in, This refers to the mud content.

[0022] Optionally, determining the formation angle between the well trajectory of the mudstone and shale and the formation includes:

[0023] The dip angle of mudstone and shale formations can be calculated using the pre-defined top-bottom relationship of the directional stratigraphic position or the gamma symmetric back-cut method.

[0024] The formation dip angle is used to calculate the formation angle between the well trajectory and the formation.

[0025] The formula for calculating the dip angle of a stratum is:

[0026] ;

[0027] in, The dip angle of the strata. and Let A and B be the perpendicular depths of the two symmetrical points A and B in the symmetrical tangent. and These are the horizontal displacements of two symmetrical points A and B in the symmetrical back-cutting process;

[0028] The formula for calculating the stratigraphic angle is:

[0029] ;

[0030] in, DEVI is the formation angle, and DEVI is the well inclination angle.

[0031] Optionally, the numerical simulation of the stress field in the shale well area to establish a geostress prediction plan of the target well platform and the surrounding reservoir bottom boundary includes:

[0032] Obtain data on the structural planes, layer velocity planes, thickness, density, and P-wave and S-wave velocity ratios of mudstone and shale;

[0033] Using thin plate theory and based on the structural surface, the layer velocity surface, the thickness, the density, and the P-wave and S-wave velocity ratio data, numerical simulation of the stress field in the well area of ​​mudstone and shale is performed to establish a geostress prediction plan of the target well platform and the bottom boundary of the surrounding reservoir in the well area.

[0034] Optionally, the drillability calculation of the clay content, the formation angle, and the predicted in-situ stress includes:

[0035] Drillability was calculated using fitting methods and drillability rating formulas based on clay content, formation angle, and predicted in-situ stress.

[0036] The formula for calculating the drillability grade is as follows:

[0037] ;

[0038] in, This represents the formation's drillability rating. The content of clay, The angle between the strata is denoted by θ, and Geos is the predicted geostress value.

[0039] Secondly, this application discloses a drilling optimization device based on the drillability of shale gas well reservoir mudstone and shale, comprising:

[0040] The mud content calculation module is used to calculate the mud content of mudstone in shale gas well reservoirs using logging-while-drilling data, and obtain the mud content of mudstone.

[0041] The formation angle determination module is used to determine the formation angle between the well trajectory of the mudstone and shale and the formation.

[0042] The geostress prediction value determination module is used to perform numerical simulation of the stress field in the well area of ​​mudstone and shale, so as to establish a geostress prediction plan of the target well platform and the bottom boundary of the surrounding reservoir in the well area, and determine the geostress prediction value from the geostress prediction plan.

[0043] The optimization module is used to perform drillability calculations on the mud content, formation angle, and predicted geostress value to obtain a formation drillability grade value, and to optimize the drilling process of mudstone and shale in real time using the formation drillability grade value.

[0044] Thirdly, this application discloses an electronic device, comprising:

[0045] Memory, used to store computer programs;

[0046] A processor is used to execute the computer program to implement the aforementioned drilling optimization method based on the drillability of shale gas well reservoir mudstone.

[0047] Fourthly, this application discloses a computer storage medium for storing a computer program; wherein, when the computer program is executed by a processor, it implements the steps of the aforementioned disclosed drilling optimization method based on the drillability of shale gas well reservoir mudstone.

[0048] Therefore, this application provides a drilling optimization method based on the drillability of shale and mudstone reservoirs in shale gas wells. The method includes: calculating the mud content of the shale and mudstone reservoir using logging-while-drilling data; determining the formation angle between the well trajectory and the formation; numerically simulating the stress field in the well area to establish a geostress prediction plan of the target well platform and the surrounding reservoir bottom boundary; determining the predicted geostress value from the geostress prediction plan; calculating the drillability based on the mud content, formation angle, and predicted geostress value to obtain a formation drillability grade; and using the formation drillability grade to optimize the drilling process of the shale and mudstone wells in real time. This application introduces the mud content of shale, the formation angle between the trajectory and the formation, and the predicted value of in-situ stress during the drilling process to calculate the formation drillability, thereby obtaining a formation drillability grade value. The formation drillability grade value is used to optimize the drilling process of shale in real time, reduce the deviation of formation drillability calculation, improve drilling efficiency, realize drilling optimization based on the drillability of shale gas well reservoirs, select the best drillable small layers in real time, guide the geological steering and drill bit selection of the well section to be drilled, thereby improving drilling efficiency and ensuring the smooth progress of drilling operations. Attached Figure Description

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

[0050] Figure 1 This application discloses a flowchart of a drilling optimization method based on the drillability of shale reservoir mudstone in shale gas wells.

[0051] Figure 2 This application discloses a standardized information diagram of a well foundation.

[0052] Figure 3 This application discloses a diagram showing the relationship between drillability and core compression in experimental data.

[0053] Figure 4 This application discloses a standardized information graph of logging-while-drilling curves;

[0054] Figure 5 This application discloses a purity function curve;

[0055] Figure 6 This is a graph showing the relationship between drillability and shale purity in experimental data disclosed in this application;

[0056] Figure 7This application discloses a logging-while-drilling gamma ray calculation of clay content map;

[0057] Figure 8 This application discloses a flowchart for calculating the dip angle of formations during geological steering of a horizontal well.

[0058] Figure 9 This is a diagram showing the relationship between drillability and drilling angle in experimental data disclosed in this application;

[0059] Figure 10 This application discloses a plan view for predicting well perimeter geostress in a reservoir section of a research area.

[0060] Figure 11 This is a schematic diagram of a drilling optimization device based on the drillability of shale gas well reservoir mudstone and shale disclosed in this application;

[0061] Figure 12 This application provides a structural diagram of an electronic device. Detailed Implementation

[0062] 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 embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0063] In oil and gas drilling engineering, formation drillability calculation and evaluation are crucial indicators for analyzing mechanical drilling speed and selecting drill bits. Various methods exist for calculation and evaluation, including experimental methods, drilling speed reverse estimation, the DC index (formation drillability index), sonic transit time calculation, and cuttings hardness methods. However, these methods all have limitations and time delays, making it difficult to ensure accuracy and reliability. While drillability determination is based on laboratory micro-drilling experiments, these methods are limited by various factors, such as not reflecting actual underground temperature and pressure conditions, difficulty in establishing continuous profiles, and high manpower and resource consumption. Therefore, domestic and international petroleum workers have conducted research using well logging interpretation and in-situ cuttings analysis to study formation drillability. Currently, the most widely used method in engineering is to establish formation drillability profiles using sonic transit time data from well logging data. In the Hongxing work area, sonic transit time and density data in the logging data can only be obtained after each drilling cycle, resulting in poor timeliness. Therefore, reducing the calculation bias of formation drillability, improving drilling efficiency, and achieving drilling optimization based on the drillability of shale gas reservoirs in mudstone and shale formations are problems that need to be solved in this field.

[0064] See Figure 1 As shown in the figure, this invention discloses a drilling optimization method based on the drillability of shale reservoir mudstone in shale gas wells, which may specifically include:

[0065] Step S11: Calculate the mud content of the mudstone in the shale gas well reservoir using logging-while-drilling data to obtain the mud content of the mudstone.

[0066] In this embodiment, an experimental analysis of influencing factors of shale was conducted to determine the main controlling factors affecting the drillability of shale; the relative gamma values ​​of shale were calculated using the measured gamma curves from the logging-while-drilling data to obtain the relative gamma values; the mud content of shale was calculated based on the relative gamma values; the main controlling factors include mud content, formation angle between the well trajectory and the formation, and predicted geostress values.

[0067] The formula for calculating the relative value of gamma is:

[0068] ;

[0069] Where C is the relative gamma value, and GR is the logging-while-drilling gamma value. and These represent the maximum and minimum gamma values ​​in pure mudstone, respectively.

[0070] The formula for calculating clay content is:

[0071] ;

[0072] in, 2.1 represents the mud content, and 2.1 represents the empirical coefficient for stratigraphic age in the study area.

[0073] This application, based on reservoir core drillability experiments, analyzes factors affecting drillability, identifying shale purity, well trajectory angle with the formation, and formation stress as the main controlling factors influencing shale drillability. Well foundation, drilling gamma ray, and well trajectory data are standardized. Standardized well foundation information is as follows: Figure 2 As shown, this provides a reference for subsequent fitting method analysis and calculation of drillability. The specific steps are as follows:

[0074] 1. Keeping other factors constant or the same, multiple drillability tests were conducted on cores of shale and mudstone with different silica and ash contents from the early reservoirs in the study area. The results showed that drillability is closely related to the purity of shale and mudstone, and the higher the purity of shale and mudstone, the better the drillability.

[0075] 2. Keeping other factors constant, multiple drillability tests were conducted on core samples of the same type of mudstone and shale from the previous reservoir in the study area under different pressures (0 MPa, 5 MPa, 10 MPa, 15 MPa, 20 MPa) to simulate the effect of in-situ stress. The results showed a close relationship between drillability and formation in-situ stress; the lower the compressive stress under compressive stress, the better the formation's drillability. The experimental data show the relationship between drillability and core compression as follows: Figure 3 As shown;

[0076] 3. Keeping other factors constant or the same, take the same type of mudstone and shale core from the previous reservoir in the study area and conduct multiple drilling drillability tests at different angles (0-90 degrees) with the formation under the same pressure compaction. It was found that drillability is closely related to the drilling angle. Among the drilling angles (0-90 degrees), the drilling drillability of the formation is better at (15-30 degrees) and (60-75 degrees).

[0077] 4. Since the drilling of the reservoir section in the study area adopted relatively mature drilling technology, the drilling pressure range, drill bit diameter, rotation speed and mud density are relatively fixed. Therefore, these variables that affect drillability are not considered in this method.

[0078] This application combines logging-while-drilling (LOD) data with gamma ray curves to calculate the mudstone content of the current formation's mudstone and shale. It only requires continuously updating the software in real-time with the field LOD curves, especially the gamma ray curves, replacing the old data. The old data is standardized LOD curve information, as shown in the example below. Figure 4 As shown, a purity curve for shale is then automatically calculated, revealing that the purity of the shale at the bottom of the well is approximately 90%. The specific process is as follows:

[0079] 1. Import the field logging data, mainly the gamma ray measured curves, into the data management module of the drillability calculation software in real time;

[0080] 2. Based on the calculation formula for gamma relative values, a purity function curve for mudstone and shale in the horizontal section of the reservoir is established. The purity function curve is shown in the figure below. Figure 5 As shown, the clay content is calculated based on the formula for clay content. The relationship between drillability and shale purity in the experimental data is as follows: Figure 6 As shown, the mud content calculated by logging-while-drilling gamma is as follows: Figure 7 As shown.

[0081] Step S12: Determine the formation angle between the well trajectory of the mudstone and shale and the formation.

[0082] In this embodiment, the dip angle of the mudstone and shale formation is calculated using the pre-set top-bottom relationship of the guiding layer or the gamma symmetric back-cut method; the formation dip angle is then used to calculate the formation angle between the well trajectory and the formation.

[0083] The formula for calculating the dip angle of a stratum is:

[0084] ;

[0085] in, The dip angle of the strata. and Let A and B be the perpendicular depths of the two symmetrical points A and B in the symmetrical tangent. and These are the horizontal displacements of two symmetrical points A and B in the symmetrical back-cutting process;

[0086] The formula for calculating the stratigraphic angle is:

[0087] ;

[0088] in, DEVI is the formation angle, and DEVI is the well inclination angle.

[0089] This application involves target well horizontal section steering tracking and calculating the formation angle between the well trajectory and the formation, specifically including the following steps:

[0090] 1. Calculate the formation dip angle based on the stratigraphic top-bottom relationship or the gamma-ray symmetric back-cut method (taking two symmetrical points A and B as examples); the formation dip angle calculation process during horizontal well geological steering is as follows: Figure 8 As shown;

[0091] 2. Calculate the drilling angle based on the currently measured well inclination angle, and use the drilling angle as the formation angle between the well trajectory and the formation.

[0092] For example, based on the vertical depth and horizontal displacement of the two nearest symmetrical back-cutting points A and B at the bottom of the well, the current formation dip angle is calculated to be -8.2°. o The current well inclination angle is 98 degrees. o Then the current drilling angle Among them, the relationship between drillability and drilling angle in the experimental data is as follows: Figure 9 As shown.

[0093] Step S13: Perform numerical simulation of the stress field in the well area of ​​mudstone and shale to establish a geostress prediction plan of the target well platform and the bottom boundary of the surrounding reservoir in the well area, and determine the geostress prediction value from the geostress prediction plan.

[0094] In this embodiment, data on the structural surface, layer velocity surface, thickness, density, and P-wave / S-wave velocity ratio of shale are obtained. Using thin plate theory and based on the structural surface, layer velocity surface, thickness, density, and P-wave / S-wave velocity ratio data, numerical simulation of the stress field in the shale well area is performed to establish a geostress prediction plan of the target well platform and the bottom boundary of the surrounding reservoir in the well area. The geostress prediction value is determined from the geostress prediction plan.

[0095] This application, during the drilling process of the target well, uses regional seismic geophysical data and thin-plate theory to numerically simulate the stress field in the well area, and establishes a geostress prediction plan of the target well platform and the bottom boundary of the surrounding reservoir in the well area. Specifically, it includes the following steps:

[0096] 1. In regional seismic geophysical data, collect structural surfaces of the target well's target layer frame area, including layer velocity surface, thickness, density, and P-wave and S-wave velocity ratio data;

[0097] 2. In the drilling formation, import the above five types of data into the 3D seismic body data or 2D seismic profile loading module. Using thin-plate theory, perform qualitative numerical simulation of the stress field along the well design trajectory in the well area. Establish a geostress prediction plan of the target well platform and the surrounding reservoir bottom boundary in the well area, determine the predicted geostress values, and the geostress prediction plan around the well in the reservoir section of the study area is shown below. Figure 10 As shown.

[0098] Step S14: Perform drillability calculations on the mud content, formation angle, and predicted geostress value to obtain the formation drillability grade value, and use the formation drillability grade value to optimize the drilling process of mudstone and shale in real time.

[0099] In this embodiment, the drilling capability is calculated by using the fitting method and the drillability rating calculation formula to calculate the clay content, formation angle, and predicted ground stress.

[0100] The formula for calculating the drillability grade is as follows:

[0101] ;

[0102] in, This represents the formation's drillability rating. The content of clay, The angle between the strata is denoted by denoted by Geos, which is the predicted value of the geostress. When Geos is tensile stress, - is selected, and when it is compressive stress, + is selected.

[0103] This application uses a fitting method to clarify the relationship between various controlling factors and drillability during the drilling process of the target well, and establishes a multi-factor calculation method for the drillability of shale gas well reservoirs and mudstone, specifically including the following steps:

[0104] 1. Using experimental data and mathematical statistics, it was found that the formation drillability rating is negatively correlated with the clay content, negatively correlated with the predicted geostress value, and exhibits a fluctuating relationship with the absolute value of the cosine of the formation angle.

[0105] 2. The drilling level of the formation was obtained by fitting method.

[0106] This invention fully utilizes logging data (natural gamma ray logging values), steering data (formation dip and drilling angle), and pre-exploration geophysical wellbore stress predictions during drilling in the study area. Through experimental monitoring, mathematical statistics, and linear fitting, it identifies the variation patterns of dependent variables and drillability, deriving a real-time calculation method for the drillability grade of the formation in the study area. Based on these variation patterns, the predicted drillability grade of the formation to be drilled is corrected, continuously improving the accuracy of the reservoir drillability grade calculation. This invention is simple to operate, easy to promote and apply, and can effectively reduce the calculation error of reservoir drillability in the study area. Most importantly, it can perform real-time calculations during drilling, resulting in high efficiency. It also offers unique advantages in selecting drillable small layers, geological steering of subsequent drilling sections, and drill bit selection during drilling.

[0107] In this embodiment, the shale content of the shale gas well reservoir is calculated using logging-while-drilling data to obtain the shale content; the formation angle between the well trajectory and the formation is determined; the stress field of the shale well area is numerically simulated to establish a geostress prediction plan of the target well platform and the surrounding reservoir bottom boundary, and the geostress prediction value is determined from the geostress prediction plan; the drillability is calculated based on the shale content, the formation angle, and the geostress prediction value to obtain the formation drillability level, and the drilling process of the shale is optimized in real time using the formation drillability level. This application introduces the mud content of shale, the formation angle between the trajectory and the formation, and the predicted value of in-situ stress during the drilling process to calculate the formation drillability, thereby obtaining a formation drillability grade value. The formation drillability grade value is used to optimize the drilling process of shale in real time, reduce the deviation of formation drillability calculation, improve drilling efficiency, realize drilling optimization based on the drillability of shale gas well reservoirs, select the best drillable small layers in real time, guide the geological steering and drill bit selection of the well section to be drilled, thereby improving drilling efficiency and ensuring the smooth progress of drilling operations.

[0108] See Figure 11 As shown, this invention discloses a drilling optimization device based on the drillability of shale gas well reservoir mudstone, which may specifically include:

[0109] The clay content calculation module 11 is used to calculate the clay content of shale gas well reservoirs using logging-while-drilling data, and obtain the clay content of shale.

[0110] Formation angle determination module 12 is used to determine the formation angle between the well trajectory of the mudstone and the formation;

[0111] The geostress prediction value determination module 13 is used to perform numerical simulation of the stress field in the well area of ​​mudstone and shale, so as to establish a geostress prediction plan of the target well platform and the bottom boundary of the surrounding reservoir in the well area, and determine the geostress prediction value from the geostress prediction plan.

[0112] The optimization module 14 is used to perform drillability calculations on the mud content, the formation angle, and the predicted geostress value to obtain the formation drillability grade value, and to optimize the drilling process of mudstone and shale in real time using the formation drillability grade value.

[0113] In this embodiment, the shale content of the shale gas well reservoir is calculated using logging-while-drilling data to obtain the shale content; the formation angle between the well trajectory and the formation is determined; the stress field of the shale well area is numerically simulated to establish a geostress prediction plan of the target well platform and the surrounding reservoir bottom boundary, and the geostress prediction value is determined from the geostress prediction plan; the drillability is calculated based on the shale content, the formation angle, and the geostress prediction value to obtain the formation drillability level, and the drilling process of the shale is optimized in real time using the formation drillability level. This application introduces the mud content of shale, the formation angle between the trajectory and the formation, and the predicted value of in-situ stress during the drilling process to calculate the formation drillability, thereby obtaining a formation drillability grade value. The formation drillability grade value is used to optimize the drilling process of shale in real time, reduce the deviation of formation drillability calculation, improve drilling efficiency, realize drilling optimization based on the drillability of shale gas well reservoirs, select the best drillable small layers in real time, guide the geological steering and drill bit selection of the well section to be drilled, thereby improving drilling efficiency and ensuring the smooth progress of drilling operations.

[0114] In some specific embodiments, the mud content calculation module 11 may specifically include:

[0115] The influencing factor experimental analysis module is used to conduct influencing factor experimental analysis on mudstone and shale to determine the main controlling factors affecting the drillability of mudstone and shale; the main controlling factors include mud content, formation angle between well trajectory and formation, and predicted in-situ stress value.

[0116] In some specific embodiments, the mud content calculation module 11 may specifically include:

[0117] The gamma relative value calculation module is used to calculate the gamma relative value of mudstone and shale using the gamma measured curve in the logging-while-drilling data, so as to obtain the gamma relative value.

[0118] The mudstone content calculation module is used to calculate the mudstone content of mudstone based on the gamma relative value.

[0119] In some specific embodiments, the formula for calculating the relative gamma value is:

[0120] ;

[0121] Where C is the relative gamma value, and GR is the logging-while-drilling gamma value. and These represent the maximum and minimum gamma values ​​in pure mudstone, respectively.

[0122] The formula for calculating clay content is:

[0123] ;

[0124] in, This refers to the mud content.

[0125] In some specific embodiments, the formation angle determination module 12 may specifically include:

[0126] The mudstone and shale formation dip angle calculation module is used to calculate the formation dip angle of mudstone and shale using the preset top-bottom relationship of the directional layer or the gamma symmetric back-cut method;

[0127] The formation angle calculation module is used to calculate the formation angle between the well trajectory and the formation based on the formation dip angle.

[0128] The formula for calculating the dip angle of a stratum is:

[0129] ;

[0130] in, The dip angle of the strata. and Let A and B be the perpendicular depths of the two symmetrical points A and B in the symmetrical tangent. and These are the horizontal displacements of two symmetrical points A and B in the symmetrical back-cutting process;

[0131] The formula for calculating the stratigraphic angle is:

[0132] ;

[0133] in, DEVI is the formation angle, and DEVI is the well inclination angle.

[0134] In some specific embodiments, the geostress prediction value determination module 13 may specifically include:

[0135] The data acquisition module is used to acquire data on the structural surfaces, layer velocity surfaces, thickness, density, and P-wave and S-wave velocity ratios of mudstone and shale.

[0136] The numerical simulation module is used to perform numerical simulation of the stress field in the well area of ​​mudstone and shale using thin plate theory and based on the structural surface, the layer velocity surface, the thickness, the density, and the P-wave and S-wave velocity ratio data, so as to establish a geostress prediction plan of the target well platform and the bottom boundary of the surrounding reservoir in the well area.

[0137] In some specific embodiments, the optimization module 14 may specifically include:

[0138] The drillability calculation module is used to calculate drillability based on clay content, formation angle, and predicted ground stress using fitting methods and drillability grade calculation formulas.

[0139] The formula for calculating the drillability grade is as follows:

[0140] ;

[0141] in, This represents the formation's drillability rating. The content of clay, The angle between the strata is denoted by θ, and Geos is the predicted geostress value.

[0142] Figure 12 This is a schematic diagram of an electronic device provided in an embodiment of this application. The electronic device 20 may specifically include: at least one processor 21, at least one memory 22, a power supply 23, a communication interface 24, an input / output interface 25, and a communication bus 26. The memory 22 stores a computer program, which is loaded and executed by the processor 21 to implement relevant steps in the drilling optimization method based on the drillability of shale gas well reservoir mudstone and shale, as disclosed in any of the foregoing embodiments.

[0143] In this embodiment, the power supply 23 is used to provide operating voltage for each hardware device on the electronic device 20; the communication interface 24 can create a data transmission channel between the electronic device 20 and external devices, and the communication protocol it follows can be any communication protocol applicable to the technical solution of this application, and is not specifically limited here; the input / output interface 25 is used to acquire external input data or output data to the outside world, and its specific interface type can be selected according to specific application needs, and is not specifically limited here.

[0144] In addition, the memory 22, as a carrier for resource storage, can be a read-only memory, random access memory, disk or optical disk, etc. The resources stored on it include operating system 221, computer program 222 and data 223, etc., and the storage method can be temporary storage or permanent storage.

[0145] The operating system 221 manages and controls the various hardware devices on the electronic device 20 and the computer program 222 to enable the processor 21 to perform calculations and processing on the data 223 in the memory 22. It can be Windows, Unix, Linux, etc. The computer program 222, in addition to including a computer program capable of performing the drilling optimization method based on the drillability of shale gas well reservoir mudstone and shale disclosed in any of the foregoing embodiments, may further include computer programs capable of performing other specific tasks. The data 223 may include data received by the drilling optimization equipment based on the drillability of shale gas well reservoir mudstone and shale and transmitted from external devices, as well as data collected by its own input / output interface 25.

[0146] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0147] Furthermore, this application also discloses a computer-readable storage medium storing a computer program. When the computer program is loaded and executed by a processor, it implements the drilling optimization method steps based on the drillability of shale gas well reservoir mudstone disclosed in any of the foregoing embodiments.

[0148] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0149] The above provides a detailed description of the drilling optimization method, apparatus, equipment, and storage medium based on the drillability of shale gas well reservoir mudstone and shale provided by the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. 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 the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A drilling optimization method based on the drillability of shale reservoir mudstone in shale gas wells, characterized in that, include: The mud content of mudstone in shale gas well reservoirs was calculated using logging-while-drilling data. Determine the formation angle between the well trajectory and the formation in the mudstone and shale formation; Numerical simulation of the stress field in the well area of ​​mudstone and shale is performed to establish a geostress prediction plan of the target well platform and the bottom boundary of the surrounding reservoir in the well area, and the geostress prediction value is determined from the geostress prediction plan. Drillability calculations are performed on the mud content, formation angle, and predicted geostress to obtain a formation drillability grade. The drilling process for mudstone and shale is then optimized in real time using the formation drillability grade.

2. The drilling optimization method based on the drillability of shale gas well reservoir mudstone as described in claim 1, characterized in that, Before calculating the mudstone content of shale gas well reservoirs using logging-while-drilling data, the following steps are also included: Experimental analysis of influencing factors of mudstone and shale was conducted to determine the main controlling factors affecting the drillability of mudstone and shale. The main controlling factors include mud content, formation angle between well trajectory and formation, and predicted in-situ stress.

3. The drilling optimization method based on the drillability of shale gas well reservoir mudstone as described in claim 1, characterized in that, The calculation of mudstone content in shale gas well reservoirs using logging-while-drilling data includes: The relative gamma values ​​of mudstone and shale were calculated using the measured gamma curves from the logging-while-drilling data. The mud content of the mudstone and shale was calculated based on the gamma relative value.

4. The drilling optimization method based on the drillability of shale gas well reservoir mudstone as described in claim 3, characterized in that, The formula for calculating the relative value of gamma is: ； Where C is the relative gamma value, and GR is the logging-while-drilling gamma value. and These represent the maximum and minimum gamma values ​​in pure mudstone, respectively. The formula for calculating clay content is: ； in, This refers to the mud content.

5. The drilling optimization method based on the drillability of shale gas well reservoir mudstone as described in claim 1, characterized in that, Determining the formation angle between the well trajectory of the mudstone and shale and the formation includes: The dip angle of mudstone and shale formations can be calculated using the pre-defined top-bottom relationship of the directional stratigraphic position or the gamma symmetric back-cut method. The formation dip angle is used to calculate the formation angle between the well trajectory and the formation. The formula for calculating the dip angle of a stratum is: ； in, The dip angle of the strata. and Let A and B be the perpendicular depths of the two symmetrical points A and B in the symmetrical tangent. and These are the horizontal displacements of two symmetrical points A and B in the symmetrical back-cutting process; The formula for calculating the stratigraphic angle is: ； in, DEVI is the formation angle, and DEVI is the well inclination angle.

6. The drilling optimization method based on the drillability of shale gas well reservoir mudstone as described in claim 1, characterized in that, The numerical simulation of the stress field in the shale well area, to establish a geostress prediction plan of the target well platform and the surrounding reservoir bottom boundary, includes: Obtain data on the structural planes, layer velocity planes, thickness, density, and P-wave and S-wave velocity ratios of mudstone and shale; Using thin plate theory and based on the structural surface, the layer velocity surface, the thickness, the density, and the P-wave and S-wave velocity ratio data, numerical simulation of the stress field in the well area of ​​mudstone and shale is performed to establish a geostress prediction plan of the target well platform and the bottom boundary of the surrounding reservoir in the well area.

7. The drilling optimization method based on the drillability of shale gas well reservoir mudstone and shale according to any one of claims 1 to 6, characterized in that, The drillability calculation for the clay content, the formation angle, and the predicted in-situ stress includes: Drillability was calculated using fitting methods and drillability rating formulas based on clay content, formation angle, and predicted in-situ stress. The formula for calculating the drillability grade is as follows: ； in, This represents the formation's drillability rating. The content of clay, The angle between the strata is denoted by θ, and Geos is the predicted geostress value.

8. A drilling optimization device based on the drillability of shale gas well reservoir mudstone, characterized in that, include: The mud content calculation module is used to calculate the mud content of mudstone in shale gas well reservoirs using logging-while-drilling data, and obtain the mud content of mudstone. The formation angle determination module is used to determine the formation angle between the well trajectory of the mudstone and shale and the formation. The geostress prediction value determination module is used to perform numerical simulation of the stress field in the well area of ​​mudstone and shale, so as to establish a geostress prediction plan of the target well platform and the bottom boundary of the surrounding reservoir in the well area, and determine the geostress prediction value from the geostress prediction plan. The optimization module is used to perform drillability calculations on the mud content, formation angle, and predicted geostress value to obtain a formation drillability grade value, and to optimize the drilling process of mudstone and shale in real time using the formation drillability grade value.

9. An electronic device, characterized in that, include: Memory, used to store computer programs; A processor for executing the computer program to implement the drilling optimization method based on the drillability of shale gas well reservoir mudstone as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, Used to store computer programs; wherein, when the computer programs are executed by a processor, they implement the drilling optimization method based on the drillability of shale gas well reservoir mudstone as described in any one of claims 1 to 7.

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