A method, system and device for friction quantitative analysis in directional drilling process

Abstract

This invention relates to the field of exploration and development, and discloses a method, system, and equipment for quantitative analysis of friction resistance in directional drilling. The method includes: acquiring logging information and drill bit speed in the drilled section; constructing a drilling speed prediction model using the drill bit speed and the composite drilling data; determining a bottom hole pressure prediction model based on the directional drilling data and the drilling speed prediction model; combining the bottom hole pressure prediction model with the surface pressure to determine a drill string axial friction resistance model; and calculating the axial friction resistance in the real-time directional drilling process using the drill string axial friction resistance model based on the logging information and drill bit speed. The quantitative friction resistance analysis method disclosed in this application solves the problem of difficulty in accurately assessing bottom hole pressure and axial friction resistance, enabling dynamic assessment of theoretical bottom hole pressure and axial friction resistance. It allows for full-process monitoring and post-drilling analysis of sliding drilling, providing a basis for improving the bottom hole drill string load condition.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of exploration and development technology, and in particular to a method, system and equipment for quantitative analysis of friction in directional drilling processes. Background Technology

[0002] As oil and gas exploration and development gradually enters complex areas such as deep and ultra-deep formations, offshore areas, and unconventional environments, directional drilling and horizontal drilling have become the main means of increasing reserves and production. Directional drilling requires the use of relevant drilling tools to dynamically adjust the wellbore trajectory to accurately encounter the target oil and gas reservoir. Currently, the main directional drilling technologies are bent screw directional drilling and rotary steerable drilling. Rotary steerable drilling is highly efficient but costly, and the build-up rate often cannot meet the trajectory control requirements for high build-up rates. Bent screw drilling tools are inexpensive and technologically mature, and still have a wide range of applications.

[0003] During the directional drilling process with curved screw drills, sliding drilling (locking the top drive or rotary table to maintain a surface rotation speed of 0) is required. Different well inclination or azimuth control targets are achieved by adjusting the tool face angle. In sliding drilling, theoretically, the drill string assembly "lies" on the wellbore. Drilling pressure is applied to the bottom of the well by lowering the drill string, and hydraulic energy drives the screw drill string to output rotation speed, ultimately achieving rock breaking and trajectory control. For long horizontal sections and complex trajectory sections, sliding drilling often involves a "pressure drag" phenomenon, where high axial resistance is generated along the drill string assembly. Drilling pressure applied from the surface cannot be effectively transmitted to the drill bit, leading to low mechanical drilling rate, uneven load on the bottom drill string assembly, and drill string "sticking," affecting drilling cycle, tool life, and construction safety.

[0004] Without downhole engineering parameter measurement subs, the determination of whether "stuck pressure" has occurred and its severity at the drilling site relies primarily on the subjective judgment of technicians based on drilling time or mechanical drilling speed under different drilling pressures. This is highly experience-based and makes it difficult to quantitatively assess the friction and bottom hole drilling pressure during the sliding drilling process. Traditional friction torque analysis models depend on hook load and torque calibration models, which are insufficient to accurately describe the friction of drill strings thousands of meters long in the wellbore, and their accuracy is insufficient to meet the requirements for bottom hole drilling pressure calculation. Summary of the Invention

[0005] The purpose of this invention is to provide at least one method, system, and device for quantitative analysis of friction during directional drilling, which can at least solve the problem of difficulty in accurately assessing bottom hole drilling pressure and axial friction, and can at least achieve dynamic assessment of theoretical bottom hole drilling pressure and axial friction. It can realize full-process monitoring and post-drilling analysis of sliding drilling, and provide a basis for improving the bottom hole drilling tool load condition.

[0006] To address the aforementioned technical problems, at least one embodiment of this application provides a method for quantitative analysis of friction during directional drilling, comprising: acquiring logging information and drill bit speed in the drilled section; the logging information includes composite drilling data of the composite drilling section, directional drilling data of the directional drilling section, and surface drilling pressure;

[0007] A drilling speed prediction model is constructed using the drill bit speed and the composite drilling data to predict the drilling speed.

[0008] Based on the directional drilling data and the drilling speed prediction model, a bottom hole drilling pressure prediction model is determined for calculating the bottom hole drilling pressure in the directional drilling section.

[0009] The bottom hole drilling pressure prediction model is combined with the surface drilling pressure to determine the drill string axial friction model used to calculate the drill string axial friction.

[0010] The axial friction model of the drill string is used to calculate the logging information and drill bit speed during real-time directional drilling to determine the axial friction during the real-time directional drilling process.

[0011] At least one embodiment of this application also provides a friction quantitative analysis system for directional drilling processes, comprising: a data processing unit for acquiring logging information and drill bit speed in drilled sections; the logging information includes composite drilling data of composite drilling sections, directional drilling data of directional drilling sections, and surface drilling pressure;

[0012] The model building unit constructs a drilling speed prediction model for predicting drilling speed using the drill bit speed and the composite drilling data; determines a bottom hole drilling pressure prediction model for calculating the bottom hole drilling pressure in the directional drilling section based on the directional drilling data and the drilling speed prediction model; and combines the bottom hole drilling pressure prediction model with the surface drilling pressure to determine a drill string axial friction model for calculating the drill string axial friction.

[0013] The friction calculation unit is used to calculate the axial friction during real-time directional drilling by using the drill string axial friction model to calculate the logging information and drill bit speed during the real-time directional drilling process.

[0014] At least one embodiment of this application also provides an electronic device, including: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the above-described friction quantitative analysis method.

[0015] At least one embodiment of this application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the analysis method described above.

[0016] The embodiments of this application provide a method, system, and equipment for quantitative analysis of friction in directional drilling processes. By fitting the drilling rate equation to composite drilling data during the composite drilling process, a drilling rate prediction model is obtained. Then, the theoretical bottom hole pressure is calculated by back-calculating the dynamic changes in directional drilling data during the sliding drilling process, i.e., the directional drilling process. The theoretical axial friction can be calculated using the surface drilling pressure and the theoretical bottom hole drilling pressure during the directional drilling process, thereby achieving quantitative analysis of friction in the sliding drilling process of directional wells. This enables accurate analysis of axial friction and allows for dynamic analysis of sliding drilling efficiency and quantitative estimation of friction even without a downhole engineering parameter measurement sub. It can provide a basis for optimizing drilling efficiency, optimizing drilling fluid performance, improving bottom hole tool load, and evaluating the effectiveness of friction reduction tools.

[0017] In some optional embodiments, the step of constructing a drilling speed prediction model using the drill bit speed and the composite drilling data to predict drilling speed includes:

[0018] The mechanical drilling rate equation is used to calculate the drilling rate by fitting the composite drilling data and the drill bit speed.

[0019] The mechanical drilling rate equation is further fitted based on the mechanical specific energy theory to determine and optimize the drilling rate prediction model; the drilling rate prediction model is used to back-calculate the bottom hole pressure during directional drilling.

[0020] In some optional embodiments, the mechanical drilling rate equation includes:

[0021] ROP = f(WOB, rpm) Bit ,Q);

[0022] Where ROP is the mechanical drilling rate; WOB is the surface drilling pressure, in kN; rpm Bit Q is the drill bit rotation speed, in r / min; Q is the drilling fluid discharge rate, in L / s.

[0023] The drilling rate prediction model includes:

[0024]

[0025] Where: μ is the sliding friction coefficient; RPM is the turntable rotation speed, in r / min; CCS is the rock strength, in MPa; EFF M For rock-breaking efficiency; A B The wellbore area is expressed in meters (m²). 2 ;D B This refers to the drill bit diameter, in meters (m).

[0026] In some optional embodiments, the step of combining the bottom hole drilling pressure prediction model with the surface drilling pressure to determine the drill string axial friction model for calculating the drill string axial friction includes:

[0027] The bottom hole drilling pressure estimated by the bottom hole drilling pressure model is subtracted from the surface drilling pressure to generate a drill string axial friction model for calculating the drill string axial friction; the drill string axial friction model includes:

[0028] f Axial =WOB-DWOB;

[0029] In the formula, f Axial , represents axial friction; DWOB represents bottom hole drilling pressure; WOB represents surface drilling pressure.

[0030] In some optional embodiments, the bottom hole drilling pressure model includes:

[0031]

[0032] Where: μ is the coefficient of sliding friction (dimensionless); RPM is the rotary table speed, in r / min; CCS is the formation compressive strength, in MPa; EFF M For rock-breaking efficiency; A B The wellbore area is expressed in meters (m²). 2 ;D B The value is the drill bit diameter in meters (m), and ROP is the mechanical drilling speed in meters per hour (m / h).

[0033] In some optional embodiments, obtaining logging information and drill bit speed in the drilled section includes:

[0034] Obtain logging data and drill string performance parameters for the drilled section;

[0035] The logging-while-drilling data is extracted and processed to separate composite drilling data of composite drilling sections and directional drilling data of directional drilling sections.

[0036] The drill bit speed is calculated using the drill string performance parameters and the logging-while-drilling data.

[0037] In some optional embodiments, the step of extracting and processing the logging-while-drilling data to separate composite drilling data for composite drilling sections and directional drilling data for directional drilling sections includes:

[0038] Data is extracted and processed using the rotary table rotation speed from the logging-while-drilling data;

[0039] Data with a rotary table rotation speed greater than a preset threshold are identified as directional drilling data for the directional drilling section.

[0040] Data with a rotary table rotation speed lower than a preset threshold are identified as composite drilling data for the composite drilling section.

[0041] In some optional embodiments, the composite drilling data of the composite drilling section and the directional drilling data of the directional drilling section both include any one or more of the following: drilling depth, drilling pressure, rotary table speed, drilling fluid discharge, mechanical drilling speed, rock strength of the drilling section, and drill bit diameter. Attached Figure Description

[0042] One or more embodiments are illustrated by way of example with reference to the accompanying drawings, and these illustrative descriptions do not constitute a limitation on the embodiments.

[0043] Figure 1 This is a flowchart of a method for quantitative analysis of friction in a directional drilling process provided in one embodiment of this application. Figure 1 ;

[0044] Figure 2 This is provided as an embodiment of the present application. Figure 1 Step 101: Further Process Figure 1 ;

[0045] Figure 3 This is provided as an embodiment of the present application. Figure 2 Step 1012: Further process Figure 1 ;

[0046] Figure 4 This is provided as an embodiment of the present application. Figure 1 Step 102: Further Process Figure 1 ;

[0047] Figure 5 This is provided as an embodiment of the present application. Figure 1 Step 105: Further Process Figure 1 ;;

[0048] Figure 6 This is a flowchart of a method for quantitative friction measurement provided in another embodiment of this application. Figure 2 ;

[0049] Figure 7 This is a schematic diagram illustrating the analysis of a real well using a friction quantitative method provided in another embodiment of this application;

[0050] Figure 8 This is a schematic diagram illustrating the trend of friction quantitative analysis of a well's friction during drilling, provided by another embodiment of this application.

[0051] Figure 9 This is a schematic diagram of a friction quantitative analysis system provided in another embodiment of this application;

[0052] Figure 10 This is a schematic diagram of the structure of an electronic device provided in another embodiment of this application. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the various embodiments of this application will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the various embodiments of this application to help readers better understand this application. However, the technical solutions claimed in this application can be implemented even without these technical details and various changes and modifications based on the following embodiments. The division of the various embodiments below is for the convenience of description and should not constitute any limitation on the specific implementation of this application. The various embodiments can be combined with and referenced by each other without contradiction.

[0054] To facilitate understanding of the embodiments of this application, relevant content regarding the drilling process will be introduced first.

[0055] As oil and gas exploration and development gradually enters complex areas such as deep and ultra-deep formations, offshore areas, and unconventional environments, directional drilling and horizontal drilling have become the main means of increasing reserves and production. Directional drilling requires the use of relevant drilling tools to dynamically adjust the wellbore trajectory to accurately encounter the target oil and gas reservoir. Currently, the main directional drilling technologies are bent screw directional drilling and rotary steerable drilling. Rotary steerable drilling is highly efficient but costly, and the build-up rate often cannot meet the trajectory control requirements for high build-up rates. Bent screw drilling tools are inexpensive and technologically mature, and still have a wide range of applications.

[0056] During the directional drilling process with curved screw drills, sliding drilling (locking the top drive or rotary table to maintain a surface rotation speed of 0) is required. Different well inclination or azimuth control targets are achieved by adjusting the tool face angle. In sliding drilling, theoretically, the drill string assembly "lies" on the wellbore. Drilling pressure is applied to the bottom of the well by lowering the drill string, and hydraulic energy drives the screw drill string to output rotation speed, ultimately achieving rock breaking and trajectory control. For long horizontal sections and complex trajectory sections, sliding drilling often involves a "pressure drag" phenomenon, where high axial resistance is generated along the drill string assembly. Drilling pressure applied from the surface cannot be effectively transmitted to the drill bit, leading to low mechanical drilling rate, uneven load on the bottom drill string assembly, and drill string "sticking," affecting drilling cycle, tool life, and construction safety.

[0057] Without downhole engineering parameter measurement subs, the determination of whether "stuck pressure" has occurred and its severity at the drilling site relies primarily on the subjective judgment of technicians based on drilling time or mechanical drilling speed under different drilling pressures. This is highly experience-based and makes it difficult to quantitatively assess the friction and bottom hole drilling pressure during the sliding drilling process. Traditional friction torque analysis models depend on hook load and torque calibration models, which are insufficient to accurately describe the friction of drill strings thousands of meters long in the wellbore, and their accuracy is insufficient to meet the requirements for bottom hole drilling pressure calculation.

[0058] To address the aforementioned technical problems of accurately describing the friction of drilling tools thousands of meters long in the wellbore and the inability to meet the accuracy requirements for bottom hole drilling pressure calculation, this invention proposes a quantitative friction analysis method for directional drilling processes. The implementation details of the quantitative friction analysis method for directional drilling processes in this embodiment are described below. The following content is only for ease of understanding and is not necessary for implementing this solution.

[0059] Example 1:

[0060] The method for quantitative analysis of friction in directional drilling processes described in this embodiment can be applied to electronic devices with communication, computing, and data storage capabilities. Its specific process can be as follows: Figure 1 As shown, steps 101-105 are included, specifically:

[0061] Step 101: Obtain logging information and drill bit speed in the drilled section; the logging information includes composite drilling data of the composite drilling section, directional drilling data of the directional drilling section, and surface drilling pressure.

[0062] Specifically, the composite drilling data for the composite drilling section and the directional drilling data for the directional drilling section both include any one or more of the following: drilling depth, drilling pressure, rotary table speed, drilling fluid discharge, mechanical drilling speed, rock strength of the drilling section, and drill bit diameter.

[0063] In some examples, step 101, such as Figure 2 As shown, it includes:

[0064] Step 1011: Obtain logging data and drill string performance parameters for the drilled section;

[0065] Step 1012: Extract and process the logging data while drilling, and screen out the composite drilling data of the composite drilling section and the directional drilling data of the directional drilling section;

[0066] Step 1013: Calculate the drill bit speed using the drill string performance parameters and the logging-while-drilling data.

[0067] In step 1012, such as Figure 3 As shown, it specifically includes:

[0068] Step 10121: Extract and process the data using the rotary table rotation speed from the logging-while-drilling data;

[0069] Step 10122: Determine the data where the rotary table rotation speed is greater than the preset threshold as the directional drilling data for the directional drilling section;

[0070] Step 10123: Determine the data where the rotary table speed is less than the preset threshold as the composite drilling data of the composite drilling section.

[0071] In some examples, a preset threshold for rotary table speed is set to 3 r / min. This designates sections with rotary table speeds < 3 r / min as directional drilling sections and sections with rotary table speeds > 3 r / min as composite drilling sections. This facilitates the filtering of directional and composite drilling data using logging-while-drilling (LWD) data. LWD data refers to the various logging data recorded in real-time during the drilling process of the drilled sections while following the drill bit.

[0072] In some examples, the drill bit speed is calculated using the drill string performance parameters and the logging-while-drilling data, specifically including:

[0073] The drill bit speed is calculated based on the rotary table speed, drilling fluid displacement, and the maximum values ​​of the displacement parameters and speed corresponding to the drill string characteristics from the logging-while-drilling data. Specifically, the screw drill string output speed is calculated based on the displacement parameters per revolution combined with drilling fluid displacement information, and the drill bit speed is calculated based on the rotary table speed and screw output speed.

[0074] The specific formula for calculating drill bit rotation speed is as follows:

[0075]

[0076] Among them, rpm Bit RPM is the drill bit speed (r / min); Q is the displacement (L / s); and lps is the maximum displacement parameter corresponding to the screw drill bit model (L / s, rpm). Model This represents the maximum rotational speed (r / min) corresponding to the screw drill bit model. In this example, the drill bit model selected is H7LZ172×7.0-3, with a maximum displacement parameter of 39.4 L / s and a maximum rotational speed of 112.5 r / min.

[0077] Step 102: Construct a drilling speed prediction model using the drill bit speed and the composite drilling data to predict the drilling speed.

[0078] Specifically, such as Figure 4 As shown, step 102 includes:

[0079] Step 1021: Fit the composite drilling data and the drill bit speed to a mechanical drilling speed equation for calculating the drilling speed;

[0080] Step 1022: Further fit the mechanical drilling rate equation based on the mechanical specific energy theory, determine and optimize the drilling rate prediction model; the drilling rate prediction model is used to back-calculate the bottom hole drilling pressure during directional drilling.

[0081] In some examples, in step 1021, the fitted mechanical drilling rate equation includes:

[0082] ROP = f(WOB, rpm) Bit ,Q);

[0083] Where ROP is the mechanical drilling rate; WOB is the surface drilling pressure, in kN; rpm Bit Q is the drill bit rotation speed, in r / min; Q is the drilling fluid discharge rate, in L / s.

[0084] Drilling rate prediction models include:

[0085]

[0086] Where: μ is the sliding friction coefficient; RPM is the turntable rotation speed, in r / min; CCS is the rock strength, in MPa; EFF M For rock-breaking efficiency; A B The wellbore area is expressed in meters (m²). 2 ;D B This refers to the drill bit diameter, in meters (m).

[0087] In this embodiment, the sliding friction coefficient and rock breaking efficiency are used as model coefficients. They are optimized by inputting composite drilling data into an optimization algorithm. After continuous optimization, the optimal model coefficients are obtained, and finally the optimal drilling speed prediction model is determined.

[0088] Furthermore, in the process of predicting the theoretical drilling pressure at the bottom of a directional drilling well, the drilling rate equation established based on high rock-breaking energy is essentially extrapolated to the low rock-breaking energy scenario. The mechanical specific energy theory, which has a stable structure and strong interpretability, is selected to establish the mechanical drilling rate prediction equation, so that the drilling rate prediction model can be used to back-calculate the bottom drilling pressure of directional drilling.

[0089] Step 103: Determine the bottom hole pressure prediction model for calculating the bottom hole pressure in the directional drilling section based on the directional drilling data and the drilling speed prediction model.

[0090] Specifically, bottom hole drilling pressure prediction models include:

[0091] DWOB = f(ROP, RPM) Bit ,Q);

[0092] In the formula, ROP is the drilling speed prediction model, and RPM is... Bit Q is the drill bit rotation speed; Q is the displacement.

[0093] Furthermore, the derivation of the theoretical bottom hole pressure prediction model from the drilling rate prediction model includes:

[0094]

[0095] Where: μ is the coefficient of sliding friction (dimensionless); RPM is the rotary table speed, in r / min; CCS is the formation compressive strength, in MPa; EFF M For rock-breaking efficiency; A B The wellbore area is expressed in meters (m²). 2 ;D B The value is the drill bit diameter in meters (m), and ROP is the mechanical drilling speed in meters per hour (m / h).

[0096] In this embodiment, the sliding friction coefficient and rock breaking efficiency are model coefficients. They need to be continuously optimized by using directional drilling data to input into the optimization algorithm, so as to obtain the best model coefficients and finally determine the best bottom hole drilling pressure prediction model.

[0097] Step 104: Combine the bottom hole drilling pressure prediction model with the surface drilling pressure to determine the drill string axial friction model used to calculate the drill string axial friction.

[0098] Specifically, step 104 includes:

[0099] The bottom hole drilling pressure estimated by the bottom hole drilling pressure model is subtracted from the surface drilling pressure to generate a drill string axial friction model for calculating the drill string axial friction; the drill string axial friction model includes:

[0100] f Axial =WOB-DWOB;

[0101] In the formula, f Axial , is the axial friction; DWOB is the bottom hole drilling pressure in the directional drilling section; WOB is the surface drilling pressure in the directional drilling section.

[0102] Based on the above bottom hole drilling pressure prediction model, the axial friction f of the drill string can be further obtained. Axial for:

[0103]

[0104] Where: μ is the sliding friction coefficient (dimensionless); RPM is the rotary table speed, r / min; CCS is the formation compressive strength, MPa; EFF M For rock-breaking efficiency; A B D is the wellbore area, in m2; B is the drill bit diameter, in meters (m), and ROP is the mechanical drilling speed, in meters per hour (m / h).

[0105] Step 105: Calculate the logging information and drill bit speed during the real-time directional drilling process using the drill string axial friction model to determine the axial friction during the real-time directional drilling process.

[0106] Specifically, such as Figure 5 As shown, step 105 includes:

[0107] Step 1051: Obtain logging information during the real-time directional drilling process; the determination of this directional drilling process can be achieved by screening using the aforementioned preset threshold of rotary table rotation speed;

[0108] Step 1052: Calculate the logging information and drill bit speed during the real-time directional drilling process using the drill string axial friction model to determine the axial friction during the real-time directional drilling process.

[0109] Step 105 enables a quantitative analysis of the friction change trend during directional well sliding drilling using the drill string axial friction model. This provides a basis for optimizing drilling efficiency, drilling fluid performance, improving bottom hole load, and evaluating the effectiveness of friction reduction tools.

[0110] The friction quantitative analysis method provided in this embodiment fits the drilling rate equation to composite drilling data during the composite drilling process, thereby obtaining a drilling rate prediction model. Then, the theoretical bottom hole pressure is calculated by back-calculating the dynamic changes of directional drilling data during the sliding drilling process, i.e., the directional drilling process. The theoretical axial friction can be calculated using the surface drilling pressure and the theoretical bottom hole drilling pressure during the directional drilling process, thereby realizing the quantitative analysis of friction during the sliding drilling process of directional wells. This method can accurately analyze axial friction and achieve dynamic analysis of sliding drilling efficiency and quantitative estimation of friction without the need for downhole engineering parameter measurement subs. It can provide a basis for optimizing drilling efficiency, optimizing drilling fluid performance, improving bottom hole tool load, and evaluating the effectiveness of friction reduction tools.

[0111] Example 2:

[0112] Another embodiment of this application relates to a method for quantitative analysis of friction. The process of this method embodiment is described using actual drilling data from a certain oilfield well section:

[0113] As shown in the figure, the friction quantitative analysis method provided in this embodiment is as follows: Figure 6 As shown, the process includes the following steps: data preprocessing, working condition division, establishing a composite drilling mechanical drilling speed prediction model, initializing model parameters, parameter optimization solution, fitting a sliding drilling theoretical bottom hole pressure model, and calculating drill string axial friction. Specifically, it includes:

[0114] (1) Data preprocessing

[0115] As shown in the table below, taking a certain drill bit's dataset used for quantitative friction calculation modeling as an example, the dataset is as follows:

[0116]

[0117]

[0118] Obtain logging information for the drilled section, including depth, pressure on drill bit, rotary table speed, displacement, bit speed, rock strength, and bit size. Preprocess the data and extract composite drilling and directional drilling data to classify working conditions.

[0119] Directional drilling process: [Rotary rotation speed] < 3 r / min;

[0120] Composite drilling process: [Rotary rotation speed] > 3 r / min;

[0121] Obtain the performance parameters of the screw drill string, calculate the output speed of the screw drill string based on the displacement per revolution parameter and drilling fluid displacement information, and calculate the drill bit speed based on the rotary table speed and screw output speed:

[0122]

[0123] Among them, rpm Bit RPM is the drill bit speed (r / min); Q is the displacement (L / s); and lps is the maximum displacement parameter corresponding to the screw drill bit model (L / s, rpm). Model This represents the maximum rotational speed (r / min) corresponding to the screw drill bit model. In this example, the drill bit model selected is H7LZ172×7.0-3, with a maximum displacement parameter of 39.4 L / s and a maximum rotational speed of 112.5 r / min.

[0124] 2) Establish the drilling rate prediction equation for the composite drilling process

[0125] ① Construction of a drilling speed prediction model for composite drilling process

[0126] The performance parameters of the screw drill string are obtained. Based on the displacement per revolution parameter and drilling fluid displacement information, the output speed of the screw drill string is calculated. The drill bit speed is then calculated based on the rotary table speed and the screw output speed. The mechanical drilling rate equation is fitted using surface drilling pressure, drill bit speed, rock strength, drill bit diameter, and mechanical drilling rate data.

[0127] ROP = f(WOB, RPM) Bit Q)

[0128] Where WOB is the ground drilling load, kN; RPM Bit is the drill bit rotation speed, r / min; Q is the displacement, L / s.

[0129] ② Drilling rate fitting based on mechanical specific energy theory

[0130] In the process of predicting the theoretical drilling pressure at the bottom of sliding drilling, the essence is to extrapolate the drilling rate equation established based on high rock-breaking energy to the low rock-breaking energy scenario. The mechanical specific energy theory, which is structurally stable and highly interpretable, is used to establish a mechanical drilling rate prediction equation for back-calculating the drilling pressure at the bottom of sliding drilling. The drilling rate equation based on the mechanical specific energy theory is as follows:

[0131]

[0132] Where: μ is the coefficient of sliding friction (dimensionless); RPM is the turntable speed, r / min; CCS is the rock strength, MPa; EFF M For rock-breaking efficiency; A B D is the wellbore area, in m2; B Let μ be the drill bit size, in meters. The sliding friction coefficient μ is related to the rock-breaking efficiency EFF. M These are the model coefficients, which need to be optimized using an optimization algorithm to find the optimal model coefficients.

[0133] (3) Back calculation of theoretical drilling pressure at the bottom of the well during sliding drilling process

[0134] ① Obtain data on drill bit rotation speed, drill bit size, rock strength, and mechanical drilling speed during the sliding drilling process. Based on the mechanical drilling speed equation established for the composite drilling process, calculate the theoretical bottom hole pressure (DWOB):

[0135] DWOB = f(ROP, RPM) Bit Q)

[0136] ②Based on the drilling rate equation of the composite drilling process based on the mechanical specific energy theory, the theoretical bottom hole drilling pressure model is derived:

[0137]

[0138] Where: μ is the sliding friction coefficient (dimensionless); RPM is the rotary table speed, r / min; CCS is the formation compressive strength, MPa; EFF M For rock-breaking efficiency; A B D is the wellbore area, in m2; B Let μ be the drill bit size (m), and ROP be the mechanical drilling rate (m / h). The sliding friction coefficient μ is related to the rock-breaking efficiency EFF. M These are the model coefficients, which need to be optimized using an optimization algorithm to find the optimal model coefficients.

[0139] (4) Calculation of axial friction of drill bit

[0140] ① Drill string axial friction model

[0141] A drilling rate equation is established based on drilling parameters and mechanical drilling rate in the composite drilling section. Bottom hole pressure is estimated based on drilling parameters and mechanical drilling rate in the sliding drilling section. Then, the axial friction of the drill string is estimated by combining the surface pressure.

[0142] f Axial =WOB-DWOB

[0143] ② Calculation of axial friction of drilling tools

[0144] Based on the above theoretical bottom hole pressure (DWOB) calculation equation, the drill string axial friction f can be obtained. Axial for:

[0145]

[0146] The calculated axial friction can be used to quantitatively analyze the friction change trend during directional well sliding drilling, providing a basis for optimizing drilling efficiency, drilling fluid performance, improving bottom hole load, and evaluating the effectiveness of friction reduction tools.

[0147] like Figure 7 This is a schematic diagram illustrating the quantitative analysis of friction resistance in a specific well drilled according to the aforementioned steps in this embodiment. Based on this diagram, a trend chart of the changes in the quantitative analysis of friction resistance during drilling for this well is created, as shown below. Figure 8 As shown, this allows for visualization through the quantitative analysis trend chart of friction resistance, providing a basis for optimizing drilling efficiency, drilling fluid performance, improving bottom hole tool load, and evaluating the effectiveness of friction reduction tools.

[0148] Example 3:

[0149] Another embodiment of this application relates to a quantitative friction analysis system for directional drilling processes. The implementation details of this embodiment's quantitative friction analysis system for directional drilling processes are described below. The following details are provided for ease of understanding and are not essential for implementing this solution. A schematic diagram of the quantitative friction analysis system device for directional drilling processes in this embodiment can be seen as follows: Figure 9 As shown, it includes a data processing unit 801, a model building unit 802, and a friction calculation unit 803.

[0150] The data processing unit 801 is used to acquire logging information and drill bit speed in the drilled section; the logging information includes composite drilling data of the composite drilling section, directional drilling data of the directional drilling section, and surface drilling pressure;

[0151] The model building unit 802 constructs a drilling speed prediction model for predicting drilling speed using the drill bit speed and the composite drilling data; determines a bottom hole drilling pressure prediction model for calculating the bottom hole drilling pressure in the directional drilling section based on the directional drilling data and the drilling speed prediction model; and combines the bottom hole drilling pressure prediction model with the surface drilling pressure to determine a drill string axial friction model for calculating the drill string axial friction.

[0152] The friction calculation unit 803 is used to calculate the axial friction during the real-time directional drilling process by using the drill string axial friction model to calculate the logging information and drill bit speed.

[0153] The data processing unit 801 includes a historical data processing unit 8011 and a real-time data processing unit 8012. The historical data processing unit 8011 is used to acquire logging information and drill bit speed in the drilled section, while the real-time data processing unit 8012 is used to acquire logging information and drill bit speed during the real-time directional drilling process. By connecting the first output of the data processing unit 801 to the model building unit 802, the logging information and drill bit speed of the drilled section are input into the model building unit 802. The model building unit 802 constructs a corresponding model and optimizes it using an optimization algorithm to determine the optimal drill string axial friction model. The second output of the data processing unit 801 is connected to the friction calculation unit 803. By inputting the logging information and drill bit speed during the real-time directional drilling process into the friction calculation unit 803, the friction calculation unit 803 dynamically calculates the friction based on the drilling axial friction model, the logging information, and the drill bit speed during the directional drilling process.

[0154] Furthermore, the friction quantitative analysis system also includes a result output unit 804, which is connected to the friction calculation unit 803 to output the real-time calculated axial friction to the staff for viewing, thereby realizing dynamic analysis of sliding drilling efficiency and quantitative estimation of friction, which can provide a basis for drilling efficiency optimization, drilling fluid performance optimization, improving bottom hole tool load, and evaluating the effect of friction reduction tools.

[0155] It is worth mentioning that all modules involved in this embodiment are logical modules. In practical applications, a logical unit can be a physical unit, a part of a physical unit, or a combination of multiple physical units. Furthermore, to highlight the innovative aspects of this application, this embodiment does not introduce units that are not closely related to solving the technical problems proposed in this application; however, this does not mean that other units are absent in this embodiment.

[0156] Example 4:

[0157] Another embodiment of this application relates to an electronic device, such as... Figure 10As shown, it includes: at least one processor 901; and a memory 902 communicatively connected to the at least one processor 901; wherein the memory 902 stores instructions executable by the at least one processor 901, the instructions being executed by the at least one processor 901 to enable the at least one processor 901 to perform the friction quantitative analysis method in the above embodiments.

[0158] The memory and processor are connected via a bus, which can include any number of interconnecting buses and bridges, connecting various circuits of one or more processors and memories. The bus can also connect various other circuits, such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and will not be described further herein. The bus interface provides an interface between the bus and the transceiver. The transceiver can be a single element or multiple elements, such as multiple receivers and transmitters, providing a unit for communicating with various other devices over a transmission medium. Data processed by the processor is transmitted over the wireless medium via an antenna, which further receives data and transmits it to the processor.

[0159] The processor manages the bus and general processing, and also provides various functions, including timing, peripheral interfaces, voltage regulation, power management, and other control functions. Memory is used to store data used by the processor during operation.

[0160] Example 5:

[0161] Another embodiment of this application relates to a computer-readable storage medium storing a computer program. When executed by a processor, the computer program implements the method embodiments described above.

[0162] That is, those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing related hardware. This program is stored in a storage medium and includes several instructions to cause a device (which may be a microcontroller, chip, etc.) or processor to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0163] Those skilled in the art will understand that the above embodiments are specific embodiments for implementing this application, and in practical applications, various changes can be made to them in form and detail without departing from the spirit and scope of this application.

Claims

1. A method for quantitative analysis of friction during directional drilling, characterized in that, include: Acquire logging information and drill bit speed in the drilled section; the logging information includes composite drilling data of composite drilling sections, directional drilling data of directional drilling sections, and surface drilling pressure; A drilling speed prediction model is constructed using the drill bit speed and the composite drilling data to predict the drilling speed. Based on the directional drilling data and the drilling speed prediction model, a bottom hole drilling pressure prediction model is determined for calculating the bottom hole drilling pressure in the directional drilling section. The bottom hole drilling pressure prediction model is combined with the surface drilling pressure to determine the drill string axial friction model used to calculate the drill string axial friction. The axial friction model of the drill string is used to calculate the logging information and drill bit speed during real-time directional drilling to determine the axial friction during the real-time directional drilling process.

2. The method for quantitative analysis of friction in directional drilling process according to claim 1, characterized in that, The step of constructing a drilling speed prediction model using the drill bit speed and the composite drilling data includes: The mechanical drilling rate equation is used to calculate the drilling rate by fitting the composite drilling data and the drill bit speed. The mechanical drilling rate equation is further fitted based on the mechanical specific energy theory to determine and optimize the drilling rate prediction model; the drilling rate prediction model is used to back-calculate the bottom hole pressure during directional drilling.

3. The method for quantitative analysis of friction in directional drilling process according to claim 2, characterized in that, The mechanical drilling rate equation includes: ROP=f(WOB,rpm Bit ,Q); Where ROP is the mechanical drilling rate; WOB is the surface drilling pressure, in kN; rpm Bit Q is the drill bit rotation speed, in r / min; Q is the drilling fluid discharge rate, in L / s. The drilling rate prediction model includes: Where: μ is the sliding friction coefficient; RPM is the turntable rotation speed, in r / min; CCS is the rock strength, in MPa; EFF M For rock-breaking efficiency; A B D represents the wellbore area, in m². B This refers to the drill bit diameter, in meters (m).

4. The method for quantitative analysis of friction in directional drilling process according to claim 1, characterized in that, The step of combining the bottom hole drilling pressure prediction model with the surface drilling pressure to determine the drill string axial friction model for calculating the drill string axial friction includes: The bottom hole drilling pressure estimated by the bottom hole drilling pressure model is subtracted from the surface drilling pressure to generate a drill string axial friction model for calculating the drill string axial friction; the drill string axial friction model includes: f Axial <WOB-DWOB; In the formula, f Axial , represents axial friction; DWOB represents bottom hole drilling pressure; WOB represents surface drilling pressure.

5. The method for quantitative analysis of friction in directional drilling process according to claim 1, characterized in that, The bottom hole drilling pressure model includes: Where: μ is the coefficient of sliding friction (dimensionless); RPM is the rotary table speed, in r / min; CCS is the formation compressive strength, in MPa; EFF M For rock-breaking efficiency; A B The wellbore area is expressed in meters (m²). 2 ;D B The value is the drill bit diameter in meters (m), and ROP is the mechanical drilling speed in meters per hour (m / h).

6. The method for quantitative analysis of friction in directional drilling process according to claim 1, characterized in that, The acquisition of logging information and drill bit speed in the drilled section includes: Obtain logging data and drill string performance parameters for the drilled section; The logging-while-drilling data is extracted and processed to separate composite drilling data of composite drilling sections and directional drilling data of directional drilling sections. The drill bit speed is calculated using the drill string performance parameters and the logging-while-drilling data.

7. The method for quantitative analysis of friction in directional drilling process according to claim 6, characterized in that, The step of extracting and processing the logging-while-drilling data to separate composite drilling data for composite drilling sections and directional drilling data for directional drilling sections includes: Data is extracted and processed using the rotary table rotation speed from the logging-while-drilling data; Data with a rotary table rotation speed greater than a preset threshold are identified as directional drilling data for the directional drilling section. Data with a rotary table rotation speed lower than a preset threshold are identified as composite drilling data for the composite drilling section.

8. The method for quantitative analysis of friction in directional drilling process according to claim 1, characterized in that, The composite drilling data for the composite drilling section and the directional drilling data for the directional drilling section both include any one or more of the following: drilling depth, drilling pressure, rotary table speed, drilling fluid discharge, mechanical drilling speed, rock strength of the drilling section, and drill bit diameter.

9. A quantitative friction analysis system for directional drilling processes, characterized in that, include: The data processing unit is used to acquire logging information and drill bit speed in the drilled section; the logging information includes composite drilling data of composite drilling section, directional drilling data of directional drilling section, and surface drilling pressure; The model building unit constructs a drilling speed prediction model for predicting drilling speed using the drill bit speed and the composite drilling data; determines a bottom hole drilling pressure prediction model for calculating the bottom hole drilling pressure in the directional drilling section based on the directional drilling data and the drilling speed prediction model; and combines the bottom hole drilling pressure prediction model with the surface drilling pressure to determine a drill string axial friction model for calculating the drill string axial friction. The friction calculation unit is used to calculate the axial friction during real-time directional drilling by using the drill string axial friction model to calculate the logging information and drill bit speed during the real-time directional drilling process.

10. An electronic device, characterized in that, include: At least one processor; as well as, A memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform the friction quantitative analysis method as described in any one of claims 1 to 8.

11. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the friction quantitative analysis method according to any one of claims 1 to 8.

Images