A method and device for realizing formation lithology measurement by using formation lithology change

Abstract

This invention provides a method for measuring formation lithology using variations in formation lithology. The method includes: S1, establishing a sample library for the area to be analyzed, containing torque fluctuation samples where formation boundaries may occur; S2, measuring the drill string torque in the area to be analyzed in real time and obtaining the maximum drill string torque per unit time; S3, initiating a formation boundary judgment process when the maximum drill string torque meets preset formation boundary conditions; S4, in the formation boundary judgment process, if the drill string torque value successfully matches the torque fluctuation sample, it is considered that the drill bit is crossing the formation boundary represented by the current sample, and the drill bit's vertical depth at this point is the depth of the formation boundary. This invention is reliable in principle, simple in structure, and easy to operate and understand. It allows for more timely monitoring of the formation lithology where the drill bit is located, facilitating timely adoption of correct drilling operations in gas drilling, discovery of unknown oil and gas reservoirs, and avoidance of major accident hazards.

Description

Technical Field

[0001] This invention relates to gas drilling technology in the field of oil and gas extraction, and more specifically, to a method and apparatus for measuring formation lithology by utilizing changes in formation lithology. Background Technology

[0002] In gas drilling operations, in order to analyze and understand the downhole conditions, it is necessary to quickly grasp the formation lithology and its changes, and then take the most appropriate drilling measures.

[0003] Currently, formation lithology information is mostly obtained before drilling, that is, through the interpretation of data from adjacent wells, artificial seismic exploration, or well logging data, to guide engineering construction. However, this fixed method has the following problems:

[0004] (1) Artificial seismic exploration involves artificially generating sound waves on or near the ground and recording the sound waves from underground. By observing and analyzing the Earth's response to artificially generated seismic waves, the properties and morphology of underground rock strata are inferred by utilizing the differences in elasticity and density of the underground medium. However, this method has a large error in identifying lithology, especially stratigraphic boundaries, and it can generally only analyze shallow strata and structures.

[0005] (2) Valuable data from neighboring wells is often difficult to collect, and the data from neighboring wells can only make a preliminary prediction of the geological conditions of the well itself. It is not completely consistent with the geological data of the well itself, and there may even be a large gap. Therefore, logging is required after drilling to adjust and correct the prediction results. However, this method has a certain lag and it is difficult to adjust the construction plan during the drilling process.

[0006] (3) Although logging-while-drilling technology can be used to monitor formation conditions in real time, this technology is not mature and has not been widely promoted and used due to the limitations of downhole data transmission conditions.

[0007] Therefore, the present invention provides a method and apparatus for measuring stratigraphic lithology by utilizing stratigraphic lithological variations. Summary of the Invention

[0008] To address the shortcomings of existing technologies, this invention aims to provide a method for measuring formation lithology by utilizing changes in formation lithology. This method is reliable in principle, simple in structure, easy to operate and understand, and can solve the problem of rapid formation lithology measurement in gas drilling.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A method for measuring stratigraphic lithology using variations in stratigraphic lithology, the method comprising the following steps:

[0011] S1. Establish a sample library for the area to be analyzed, which contains torque fluctuation samples that may occur at stratigraphic interfaces;

[0012] S2. Measure the drill string torque value in the area to be analyzed in real time and analyze the maximum value of the drill string torque per unit time.

[0013] S3. When the maximum value of the drill string torque meets the preset conditions for formation boundary, the formation boundary judgment process is initiated.

[0014] S4. In the formation boundary determination process, if the drill string torque value is successfully compared with the torque value fluctuation sample, it is considered that the drill bit is crossing the formation boundary represented by the current sample, and the vertical depth of the drill bit at this time is the depth of the formation boundary.

[0015] According to one embodiment of the present invention, the torque fluctuation sample is composed of a preset number of drill string torque values ​​per unit time.

[0016] According to an embodiment of the present invention, step S2 specifically includes the following steps:

[0017] The drill string torque value is measured in real time by a drill string torque measuring device installed on the ground, and the drill string torque value is transmitted to the logging system.

[0018] The torque value of the drill string is recorded in real time by the torque recording module in the logging system.

[0019] The torque analysis and calculation module in the logging system reads the drill string torque value from the torque recording module and performs real-time analysis to obtain the maximum value of the drill string torque per unit time.

[0020] According to one embodiment of the invention, the unit time is set to be 10 times the time between the two torque peaks.

[0021] According to one embodiment of the present invention, if the maximum value T of the drill string torque per unit time is... s The following conditions must be met:

[0022] ;

[0023] If the drilling strata have not changed, the stratum boundary preset conditions are not met, and there is no need to initiate the stratum boundary judgment process.

[0024] Among them, T s For the current unit of time t s Maximum drill string torque within; T s-1 For the previous unit of time t s-1 The maximum torque of the drill string within the range; This is the first torque fluctuation coefficient.

[0025] According to one embodiment of the present invention, if the maximum value T of the drill string torque per unit time is... s The following conditions must be met:

[0026] ;

[0027] If the drilling strata lithology may have changed significantly, or if the drill bit is crossing a stratum boundary region, meeting the stratum boundary preset conditions, the stratum boundary judgment process needs to be initiated.

[0028] Among them, T s For the current unit of time t s Maximum drill string torque within; T s-1 For the previous unit of time t s-1 The maximum torque of the drill string within the range; This is the second torque fluctuation coefficient.

[0029] According to one embodiment of the present invention, the drill string torque value is compared with the torque value fluctuation sample by a vector comparison method.

[0030] According to an embodiment of the present invention, step S4 specifically includes the following steps:

[0031] The drill string torque value is regarded as the measured vector, and the torque value fluctuation sample is regarded as the sample vector. The distance between the measured vector and each sample vector is calculated to obtain the vector distance value corresponding to each sample vector.

[0032] A distance threshold is set. If a vector distance value is less than the distance threshold, it indicates that the comparison is successful and the drill bit is crossing the formation interface represented by the current sample vector.

[0033] If multiple vector distance values ​​are less than the distance threshold, the smallest vector distance value is taken, indicating that the drill bit is most likely to cross the formation interface represented by the current sample vector.

[0034] According to another aspect of the invention, a storage medium is also provided, which includes a series of instructions for performing the steps of the method described in any of the preceding claims.

[0035] According to another aspect of the present invention, an apparatus for performing stratigraphic lithology measurement by utilizing stratigraphic lithology variations is also provided, which performs the method for performing stratigraphic lithology measurement by utilizing stratigraphic lithology variations as described in any of the preceding claims, the apparatus comprising:

[0036] The sample library module is used to establish a sample library for the area to be analyzed, which contains torque numerical fluctuation samples that may occur at stratigraphic interfaces.

[0037] The drill string torque maximum value module is used to measure the drill string torque value in the area to be analyzed in real time and obtain the maximum drill string torque value per unit time.

[0038] The judgment module is used to initiate the formation boundary judgment process when the maximum value of the drill string torque meets the preset conditions for formation boundary.

[0039] The formation boundary determination module is used in the formation boundary determination process. If the drill string torque value is successfully compared with the torque value fluctuation sample, it is considered that the drill bit is crossing the formation boundary represented by the current sample. At this time, the vertical depth of the drill bit is the depth of the formation boundary.

[0040] The present invention provides a method and apparatus for measuring stratigraphic lithology by utilizing stratigraphic lithological variations, the advantages of which are as follows:

[0041] Because there is no mud in the wellbore during gas drilling, the drill string vibration is significantly higher than in mud drilling, and the transmission of drill bit torque signals is more direct and rapid. This makes the detection of drill bit torque changes on the ground more reliable, and the detected torque change signals contain richer and more valuable information.

[0042] Under normal gas drilling conditions, although the drill string torque value exhibits some randomness, it generally fluctuates within a small range over time. However, when the formation lithology changes, drill string vibration intensifies, the torque variation widens, and the torque measurement signal waveform undergoes anomalies. This is of great significance for determining changes in formation lithology or formation interfaces.

[0043] The method of this invention enables more timely monitoring of the lithology of the formation where the drill bit is located, which is conducive to the timely adoption of the correct drilling operation plan during gas drilling operations, the discovery of unknown oil and gas reservoirs, and the avoidance of major accident risks.

[0044] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the description and the drawings. Attached Figure Description

[0045] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with the embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0046] Figure 1 A flowchart illustrating a method for measuring stratigraphic lithology using stratigraphic lithological variations according to an embodiment of the present invention is shown.

[0047] Figure 2 A flowchart of a method for determining the maximum drill string torque per unit time according to an embodiment of the present invention is shown;

[0048] Figure 3 A flowchart for determining stratigraphic boundaries according to an embodiment of the present invention is shown; and

[0049] Figure 4 A structural block diagram of an apparatus for measuring stratigraphic lithology by utilizing stratigraphic lithological variations, according to an embodiment of the present invention, is shown.

[0050] In the accompanying drawings, the same parts use the same reference numerals. Also, the drawings are not drawn to scale. Detailed Implementation

[0051] The present invention will be further described below. It should be noted that this embodiment is based on the present technical solution and provides detailed implementation methods and specific operation processes, but the scope of protection of the present invention is not limited to this embodiment. To make the objectives, technical solutions and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0052] Figure 1 A flowchart illustrating a method for measuring stratigraphic lithology using stratigraphic lithological variations according to an embodiment of the present invention is shown.

[0053] like Figure 1 As shown, in step S101, a sample library is established for the area to be analyzed. The sample library contains torque numerical fluctuation samples that may appear at stratigraphic interfaces.

[0054] Specifically, based on the stratigraphic distribution of the area to be analyzed, a sample library of torque fluctuations that may occur at stratigraphic boundaries is established as a comparison sample for the stratigraphic boundary judgment process.

[0055] In one embodiment, the torque fluctuation sample consists of a preset number of drill string torque values ​​per unit time. Specifically, the samples in the torque fluctuation sample library for each formation interface consist of p drill string torque values ​​per unit time. It should be noted that the specific value of p can be set according to the drilling plan and drilling time parameters for this well.

[0056] like Figure 1 As shown, in step S102, the drill string torque value of the area to be analyzed is measured in real time, and the maximum value of the drill string torque per unit time is obtained.

[0057] Specifically, the drill string torque value is measured in real time using existing ground-based drill string torque measuring devices, and the maximum drill string torque T per unit time is calculated.s .

[0058] In one embodiment, Figure 2 A flowchart of a method for determining the maximum drill string torque per unit time according to an embodiment of the present invention is shown.

[0059] like Figure 2 As shown, in step S201, the drill string torque value is measured in real time by a drill string torque measuring device installed on the ground, and the drill string torque value is transmitted to the logging system.

[0060] Specifically, the drill string torque value is measured in real time by existing ground-based drill string torque measurement devices and transmitted to the logging system. The logging system records the drill string torque value in real time and performs real-time analysis to determine the maximum drill string torque T per unit time. s .

[0061] like Figure 2 As shown, in step S202, the drill string torque value is recorded in real time by the torque recording module in the logging system. In this embodiment, a torque recording module is installed in the logging system to record the drill string torque value in real time.

[0062] like Figure 2 As shown, in step S203, the torque analysis and calculation module in the logging system reads the drill string torque value from the torque recording module and performs real-time analysis to obtain the maximum drill string torque value T within the current unit time. In this embodiment, a torque analysis and calculation module is installed in the logging system. This module is used to read the real-time drill string torque value from the torque recording module and perform real-time analysis to obtain the maximum drill string torque value T within the current unit time. s .

[0063] In one embodiment, the unit time is set to 10 times the time between two torque peaks. It should be noted that the specific value of the unit time needs to be determined based on the torque value recorded in the logging relative to the peak value. Generally, it is advisable to take 10 times the time between two torque peaks. This invention does not impose any restrictions on the setting of the unit time.

[0064] like Figure 1 As shown, in step S103, when the maximum value of the drill string torque meets the preset conditions for formation boundary, the formation boundary judgment process is initiated.

[0065] Specifically, it is determined whether the maximum value of the drill string torque within the current unit time meets the preset conditions for formation boundary, so as to determine whether the formation boundary judgment process needs to be initiated, i.e., step S104.

[0066] In one embodiment, if the maximum drill string torque T per unit time is... sThe following conditions must be met:

[0067] ;

[0068] If the drilling strata have not changed and do not meet the preset conditions for stratum boundary, then there is no need to initiate the stratum boundary judgment process.

[0069] Among them, T s For the current unit of time t s Maximum drill string torque within; T s-1 For the previous unit of time t s-1 The maximum torque of the drill string within the range; This is the first torque fluctuation coefficient, which is generally positive.

[0070] It should be noted that the torque fluctuation coefficient is set based on experience. It can be determined by referring to the torque fluctuation of each unit time during the drilling process recorded in the logging data of adjacent wells that have been drilled, or it can be obtained through laboratory tests or field tests. This invention does not impose any restrictions on the specific value of the torque fluctuation coefficient.

[0071] In one embodiment, if the maximum drill string torque T per unit time is... s The following conditions must be met:

[0072] ;

[0073] If the drilling strata lithology has changed significantly, or if the drill bit is crossing a stratum boundary region and meets the preset conditions for stratum boundary determination, the stratum boundary determination process needs to be initiated.

[0074] Among them, T s For the current unit of time t s Maximum drill string torque within; T s-1 For the previous unit of time t s-1 The maximum torque of the drill string within the range; This is the second torque fluctuation coefficient, which is generally negative.

[0075] like Figure 1 As shown, in step S104, in the formation boundary judgment process, if the drill string torque value is successfully compared with the torque value fluctuation sample, it is considered that the drill bit is crossing the formation boundary represented by the current sample, and the vertical depth of the drill bit at this time is the depth of the formation boundary.

[0076] Specifically, the drill string torque values ​​are read in a set number of units of time and compared with samples in the sample library. If a match is found with a sample, it is considered that the drill bit is crossing the formation interface represented by that sample, and the vertical depth of the drill bit at this time is the depth of the formation interface.

[0077] In one embodiment, the drill string torque values within the current unit time and the previous p - 1 unit times t s-p -t s are compared with the samples in the torque value fluctuation sample library of the formation interface established in step S101. If the comparison is successful with a certain sample, it is considered that the drill bit is passing through the formation interface represented by this sample, and the vertical depth of the drill bit at this time is the depth of the formation interface.

[0078] Further, the comparison between the drill string torque value and the torque value fluctuation sample is performed by the vector comparison method. Even further, the vector comparison method specifically adopts the vector distance method, such as Figure 3 . Figure 3 FIG. shows a flowchart of formation interface determination according to an embodiment of the present invention.

[0079] Such as Figure 3 shown, in step S301, the drill string torque value is regarded as the measured vector, and the torque value fluctuation sample is regarded as the sample vector. The distances between the measured vector and each sample vector are calculated respectively to obtain the vector distance values corresponding to each sample vector.

[0080] Specifically, the drill string torque values of p unit times t s-p -t s are regarded as the measured vector, and the samples in the torque value fluctuation sample library of each formation interface are regarded as the sample vectors. By using the vector comparison method of the vector distance method, the distances between the measured vector and each sample vector are calculated respectively to obtain the corresponding vector distance values Dr.

[0081] Such as Figure 3 shown, in step S302, a distance threshold is set. If there is a vector distance value less than the distance threshold, it means that the comparison is successful, and the drill bit is passing through the formation interface represented by the current sample vector.

[0082] Specifically, a distance threshold Di is set. If Dr < Di, it means that the comparison is successful, and the drill bit is passing through the formation interface represented by this sample vector.

[0083] Such as Figure 3 shown, in step S303, if there are multiple vector distance values less than the distance threshold, the smallest vector distance value is taken, indicating that the drill bit is most likely to pass through the formation interface represented by the current sample vector.

[0084] Specifically, if there are multiple Dr values less than Di, the smallest Dr value is taken, indicating that the drill bit is most likely to pass through the formation interface represented by this sample vector.

[0085] The method and apparatus for measuring stratigraphic lithology using stratigraphic lithological variations provided by this invention can also be used in conjunction with a computer-readable storage medium. The storage medium stores a computer program, which is executed to run the method for measuring stratigraphic lithology using stratigraphic lithological variations. The computer program is capable of executing computer instructions, which include computer program code. The computer program code can be in the form of source code, object code, executable files, or some intermediate form.

[0086] Computer-readable storage media can include: any entity or device capable of carrying computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc.

[0087] Figure 4 A structural block diagram of an apparatus for measuring stratigraphic lithology by utilizing stratigraphic lithological variations, according to an embodiment of the present invention, is shown.

[0088] like Figure 4 As shown, the device 400 for measuring stratigraphic lithology by utilizing stratigraphic lithological changes includes a sample library module 401, a drill string torque maximum value module 402, a judgment module 403, and a stratigraphic boundary judgment module 404.

[0089] Specifically, the sample library module 401 is used to establish a sample library for the area to be analyzed, which contains torque numerical fluctuation samples that may appear at stratigraphic interfaces.

[0090] Specifically, the drill string torque maximum value module 402 is used to measure the drill string torque value of the area to be analyzed in real time and to analyze and obtain the maximum drill string torque value per unit time.

[0091] Specifically, the judgment module 403 is used to initiate the formation boundary judgment process when the maximum value of the drill string torque meets the preset conditions for formation boundary.

[0092] Specifically, the formation boundary judgment module 404 is used in the formation boundary judgment process to determine if the drill string torque value is successfully compared with the torque value fluctuation sample. If so, it is considered that the drill bit is crossing the formation boundary represented by the current sample, and the vertical depth of the drill bit at this time is the depth of the formation boundary.

[0093] The present invention provides a method and apparatus for measuring stratigraphic lithology by utilizing stratigraphic lithological variations, the advantages of which are as follows:

[0094] Because there is no mud in the wellbore during gas drilling, the drill string vibration is significantly higher than in mud drilling, and the transmission of drill bit torque signals is more direct and rapid. This makes the detection of drill bit torque changes on the ground more reliable, and the detected torque change signals contain richer and more valuable information.

[0095] Under normal gas drilling conditions, although the drill string torque value exhibits some randomness, it generally fluctuates within a small range over time. However, when the formation lithology changes, drill string vibration intensifies, the torque variation widens, and the torque measurement signal waveform undergoes anomalies. This is of great significance for determining changes in formation lithology or formation interfaces.

[0096] The method of this invention enables more timely monitoring of the lithology of the formation where the drill bit is located, which is conducive to the timely adoption of the correct drilling operation plan during gas drilling operations, the discovery of unknown oil and gas reservoirs, and the avoidance of major accident risks.

[0097] It should be understood that the embodiments disclosed herein are not limited to the specific structures, processing steps, or materials disclosed herein, but should be extended to equivalent substitutions of these features as understood by those skilled in the art. It should also be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting.

[0098] In the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0099] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0100] The phrase "an embodiment" or "an embodiment" used in this specification means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. Therefore, the phrase "an embodiment" or "an embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment.

[0101] The embodiments of the present invention are given for illustrative and descriptive purposes only, and are not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to better illustrate the principles and practical application of the invention, and to enable those skilled in the art to understand the invention and to design various embodiments with various modifications suitable for a particular purpose.

[0102] While the embodiments disclosed in this invention are as described above, the content is merely for the purpose of facilitating understanding of the invention and is not intended to limit the invention. Any person skilled in the art to which this invention pertains may make any modifications and variations in form and detail of the implementation without departing from the spirit and scope disclosed herein; however, the scope of patent protection for this invention shall still be determined by the scope defined in the appended claims.

Claims

1. A method for measuring stratigraphic lithology using variations in stratigraphic lithology, characterized in that, The method includes the following steps: S1. Establish a sample library for the area to be analyzed, which contains torque fluctuation samples that may occur at stratigraphic interfaces; S2. Measure the drill string torque value in the area to be analyzed in real time and analyze the maximum value of the drill string torque per unit time. S3. When the maximum value of the drill string torque meets the preset conditions for formation boundary, the formation boundary judgment process is initiated. S4. In the formation boundary determination process, if the drill string torque value is successfully compared with the torque value fluctuation sample, it is considered that the drill bit is crossing the formation boundary represented by the current sample. At this time, the drill bit vertical depth is the depth of the formation boundary. If the maximum drill string torque T per unit time is s The following conditions must be met: ； If the drilling strata have not changed, the stratum boundary preset conditions are not met, and there is no need to initiate the stratum boundary judgment process. Among them, T s For the current unit of time t s Maximum drill string torque within; T s-1 For the previous unit of time t s-1 The maximum torque of the drill string within the range; This is the first torque fluctuation coefficient; If the maximum drill string torque T per unit time is s The following conditions must be met: ； If the drilling strata lithology may have changed significantly, or if the drill bit is crossing a stratum boundary region, meeting the stratum boundary preset conditions, the stratum boundary judgment process needs to be initiated. in, This is the second torque fluctuation coefficient.

2. The method for stratigraphic lithology measurement using stratigraphic lithology variations as described in claim 1, characterized in that, The torque fluctuation sample consists of a preset number of drill string torque values ​​per unit time.

3. The method for measuring stratigraphic lithology using stratigraphic lithological variations as described in claim 1, characterized in that, Step S2 specifically includes the following steps: The drill string torque value is measured in real time by a drill string torque measuring device installed on the ground, and the drill string torque value is transmitted to the logging system. The torque value of the drill string is recorded in real time by the torque recording module in the logging system. The torque analysis and calculation module in the logging system reads the drill string torque value from the torque recording module and performs real-time analysis to obtain the maximum value of the drill string torque per unit time.

4. The method for stratigraphic lithology measurement using stratigraphic lithology variations as described in claim 1, characterized in that, The unit time is set to be 10 times the time between the two torque peaks.

5. The method for measuring stratigraphic lithology using stratigraphic lithological variations as described in claim 1, characterized in that, The drill string torque value is compared with the torque value fluctuation sample using the vector comparison method.

6. The method for stratigraphic lithology measurement using stratigraphic lithology variations as described in claim 1, characterized in that, Step S4 specifically includes the following steps: The drill string torque value is regarded as the measured vector, and the torque value fluctuation sample is regarded as the sample vector. The distance between the measured vector and each sample vector is calculated to obtain the vector distance value corresponding to each sample vector. A distance threshold is set. If a vector distance value is less than the distance threshold, it indicates that the comparison is successful and the drill bit is crossing the formation interface represented by the current sample vector. If multiple vector distance values ​​are less than the distance threshold, the smallest vector distance value is taken, indicating that the drill bit is most likely to cross the formation interface represented by the current sample vector.

7. A storage medium, characterized in that, It includes a series of instructions for performing the method steps as described in any one of claims 1-6.

8. A device for measuring stratigraphic lithology by utilizing changes in stratigraphic lithology, characterized in that, The apparatus for performing a method for stratigraphic lithology measurement using stratigraphic lithology variations as described in any one of claims 1-6 comprises: The sample library module is used to establish a sample library for the area to be analyzed, which contains torque numerical fluctuation samples that may occur at stratigraphic interfaces. The drill string torque maximum value module is used to measure the drill string torque value in the area to be analyzed in real time and obtain the maximum drill string torque value per unit time. The judgment module is used to initiate the formation boundary judgment process when the maximum value of the drill string torque meets the preset conditions for formation boundary. The formation boundary determination module is used in the formation boundary determination process. If the drill string torque value is successfully compared with the torque value fluctuation sample, it is considered that the drill bit is crossing the formation boundary represented by the current sample. At this time, the vertical depth of the drill bit is the depth of the formation boundary.

Images