Stratum integrity judgment method based on digital drilling, readable storage medium and equipment

Abstract

The invention discloses a stratum integrity judgment method based on digital drilling, a readable storage medium and equipment, and belongs to the technical field of stratum lithology and geologic structure division. The concepts of the fluctuation ratio f (Sn) of a rock stratum sequence Sn in a target rock mass horizon and the quantity ratio g (Sn) of the rock stratum sequence Sn in the target rock mass horizon are proposed by utilizing the characteristic that the fluctuation change condition of a while-drilling parameter change curve reflects the rock mechanical properties of a rock stratum and a weak structural plane and the difference of the rock mechanical properties between the rock stratum and the weak structural plane; a certain amount of evaluation index f (Sn) / g (Sn) is used as a basis for judging the strength of the stratum integrity, and the influence of the number and strength of weak structural surfaces and the number of rock stratum interfaces on the stability of the geologic structure is synthesized. Compared with a method of manually counting the number of weak structural surfaces such as faults, fractures and weak intercalated layers in the stratum as the geologic structure stability in the traditional practice, the method provided by the invention is more scientific and accurate.

Description

Technical Field

[0001] The present invention relates to the technical field of stratum lithology and geological structure division, and in particular to a stratum integrity judgment method based on digital drilling and a readable storage medium and device. Background Art

[0002] During the construction of pumped-storage power stations, the stability of underground geological structures is a key issue that engineers focus on. Stratigraphic integrity refers to the degree of uniformity of the strata to which the underground structure construction layer belongs, which is related to the development of geological structural surfaces including faults, fissures, weak interlayers and other weak structural surfaces in the strata. When selecting a site for underground structures, especially in the preliminary exploration and site selection process for the construction of underground powerhouses of pumped-storage power stations, the industry often uses stratigraphic integrity as a reference for qualitative judgment of the stability of underground geological structures. The weaker the stratigraphic integrity, or the more developed the weak structural surface, the worse the stability of the underground geological structure. The industry usually chooses to avoid the relevant stratigraphic layers when selecting the site for underground powerhouses.

[0003] Since the judgment of stratigraphic integrity is based on the actual stratigraphic conditions and geological structures underground, and the determination of stratigraphic conditions and geological structures depends on accurate geological exploration results; core sampling and borehole imaging are important technical means to accurately obtain stratigraphic conditions and geological structure exploration results, but due to their high economic costs, this further limits the engineering application of stratigraphic integrity in judging the stability of underground geological structures.

[0004] Digital drilling technology is a cutting-edge technology in the field of geological exploration. It uses relevant digital drilling equipment to obtain various drilling parameters during the drilling process, such as drilling speed, rotation speed, torque, impact force, propulsion force, etc. for control, monitoring and analysis. By integrating and statistically analyzing the drilling parameters, it has been widely used in the field of stratum lithology and geological structure division, and has accumulated a certain number of research results and practical experience, which undoubtedly provides another efficient and economical way and means for judging the integrity of the stratum. However, the industry often does not have a method to judge the integrity of the stratum based on the results of digital drilling. Summary of the invention

[0005] Based on the above technical status and problems, the present invention provides a method for judging the integrity of formations based on digital drilling, and a readable storage medium and device, which can scientifically judge the integrity of formations using digital drilling results.

[0006] The present invention is implemented as follows: a method for determining formation integrity based on digital drilling, comprising the following steps:

[0007] Step 1, acquisition of drilling parameters: using a drilling rig equipped with a DPM system to perform drilling, collecting drilling parameters during the drilling process of the drilling rig, processing the collected drilling parameter data set, and obtaining a change curve of the drilling parameters during the net drilling process;

[0008] Step 2, stratigraphic geological structure division: select the target rock mass layer from the stratigraphic geological structure division result, and divide the different stratigraphic geological structures of the target rock mass layer based on the fluctuation of the while drilling parameter change curve;

[0009] Step 3: Selection and processing of drilling parameters: Obtain n rock layer sequences S in the target rock layer n , m weak interlayer sequences W m , and the rock sequence S n The corresponding thickness TS n , peak mean PS n , trough mean VS n , weak interlayer sequence W m The corresponding thickness TW m , peak mean PW m , trough mean VW m ;

[0010] Step 4: Determine the elements for evaluating stratum integrity: Determine the stratum sequence S n The fluctuation ratio f(S n ) and rock sequence S n The number ratio g(S n );

[0011] Step 5: Setting the formation integrity threshold: Setting the formation integrity threshold sequence θ i ={θ1, θ2, ..., θ n}, where from θ1 to θ n The values ​​decrease in size;

[0012] Step 6, formation integrity determination: f(S n ) / g(S n )≥θ1, the formation integrity is level one; θ2≤f(S n ) / g(S n )<θ1, the formation integrity is level 2; θ3≤f(S n ) / g(S n )<θ2, the formation integrity is level three; ...; and so on; wherein, the formation integrity gradually decreases from level one to level n+1;

[0013] Step 7: Select a target rock layer with high stratum integrity as the construction area for underground structures including underground powerhouses.

[0014] Furthermore, in step 1, the collected downhole parameter data set is processed to obtain a downhole parameter variation curve of the downhole parameters and the drilling depth during the net drilling process, specifically including: removing the downhole parameter variation curves during the drilling rig empty push, drilling rig retreat, drill rod looseness, and standby process, and obtaining the downhole parameter variation curve of the downhole parameters changing with the drilling depth D during the net drilling process.

[0015] Furthermore, the step 2 divides different stratigraphic geological structures of the target rock mass layer based on the fluctuations of the drilling parameter change curve, specifically including: selecting the drilling parameter change curve in which the drilling speed V changes with the drilling depth D, and dividing the stratigraphic geological structure into several relatively stable and fluctuating sections according to the changes in the peaks and troughs of the drilling speed V change curve, wherein the section with a sudden increase in the peak value and trough value in the drilling speed V change curve is the section where the weak interlayer is located.

[0016] Furthermore, in step 4, the rock sequence S n The fluctuation ratio f(S n ) is calculated as: f(S n )=∑(TS n ×(PS n +VS n ))÷(∑(TS n ×(PS n +VS n ))+∑(TW m ×(PW m +VW m ))), rock sequence S n The number ratio g(S n ) is calculated as follows: g(S n )=n / (m+n).

[0017] Furthermore, the step 5, setting the formation integrity threshold, specifically includes: according to practical experience and production conditions, or according to the formation sequence S n and the weak interlayer sequence W m The corresponding rock type, rock uniaxial compressive strength and other actual rock formation characteristics are comprehensively judged to set the formation integrity threshold sequence θ i The number of thresholds and the size of the thresholds.

[0018] Furthermore, in step 5, the formation integrity threshold sequence is set to θ i ={1, 1 / 3, 1 / 10};

[0019] Furthermore, in step 6, the formation integrity determination method is specifically as follows: f(S n ) / g(Sn )≥1, the formation integrity is level one; 1 / 3≤f(S n ) / g(S n )<1, the formation integrity is level 2; 1 / 10≤f(S n ) / g(S n )<1 / 3, the formation integrity is level 3; f(S n ) / g(S n )<1 / 10, the stratum integrity is level four.

[0020] A computer-readable storage medium includes a stored computer program, wherein when the computer program is executed, the device where the computer-readable storage medium is located is controlled to execute the above-mentioned formation integrity judgment method based on digital drilling.

[0021] A computer device comprises a memory, a processor and a program stored and executable on the memory, wherein when the program is executed by the processor, the steps of the above-mentioned method for determining formation integrity based on digital drilling are implemented.

[0022] The advantages and technical effects of the present invention are as follows:

[0023] 1. Using the fluctuation of the parameter variation curve while drilling to reflect the rock mechanical properties of the rock layer and the weak structural surface and the difference in the rock mechanical properties between the two, the rock layer sequence S is proposed. n The fluctuation ratio f(S n ) as an indicator for judging the integrity of the formation. When judging the integrity of the formation, the weak structural surfaces such as faults, fissures and weak interlayers are not only judged by the number of faults, fissures and weak interlayers, but also by the rock mechanical strength of faults, fissures and weak interlayers. This helps to scientifically judge the adverse effects of one or more weak structural surfaces on the integrity of the formation and the stability of the underground geological structure.

[0024] 2. Propose the rock sequence S n The number ratio g(S n ) concept, so as to incorporate the rock interface into the consideration of stratigraphic integrity, making the evaluation of underground geological structure stability more comprehensive.

[0025] 3. Propose f(S) by quantitative method n ) / g(S n) is a quantitative evaluation index, which serves as the basis for judging the strength of stratum integrity. It reveals the intrinsic geological connection between the number and strength of weak structural surfaces and the number of stratum interfaces. It comprehensively considers the number and strength of weak structural surfaces and the number of stratum interfaces to judge the overall impact on the stability of geological structures. It is more scientific and accurate than the traditional practice of relying solely on the manual counting of the number of weak structural surfaces such as faults, cracks, weak interlayers in strata as a single indicator of geological structure stability. It has a strong guiding significance for the site selection and engineering evaluation of underground structures, especially underground powerhouses. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of the stratigraphic geological structure division of the target rock mass layer;

[0027] Figure 2 Schematic diagram of the method for determining the thickness, peak mean, and trough mean corresponding to the rock sequence;

[0028] Figure 3 Schematic diagram of the method for determining the thickness, peak mean, and trough mean corresponding to the weak interlayer sequence. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation methods described herein are only used to explain the present invention and are not used to limit the present invention.

[0030] First, the relevant concepts involved in the present invention are explained.

[0031] Stratigraphic integrity refers to the degree of uniformity of the strata to which the underground structure is constructed. It is related to the development of geological structural surfaces in the strata, including faults, fissures, weak interlayers and other weak structural surfaces. The weaker the stratigraphic integrity, or the more developed the weak structural surfaces, the worse the stability of the underground geological structure.

[0032] The rock formation sequence in the target rock mass layer refers to a sequence composed of one or more adjacent or non-adjacent relatively stable rock formations in the target rock mass layer; the weak interlayer sequence in the target rock mass layer refers to a sequence composed of one or more weak interlayers in the target rock mass layer, including weak structural surfaces such as faults, fissures, and weak interlayers, which are located between two relatively stable rock formations.

[0033] The thickness corresponding to the rock formation sequence refers to the distance between the upper and lower layers of a certain rock formation in the rock formation sequence in the depth direction; the thickness corresponding to the weak interlayer sequence refers to the distance between the upper and lower layers of a certain weak interlayer in the weak interlayer sequence in the depth direction. The peak mean and trough mean corresponding to the rock formation sequence refer to the average value of all peak values ​​and the average value of all trough values ​​corresponding to a certain rock formation in the rock formation sequence in the while drilling parameter variation curve; the peak mean and trough mean corresponding to the weak interlayer sequence refer to the average value of all peak values ​​and the average value of all trough values ​​corresponding to a certain weak interlayer in the weak interlayer sequence in the while drilling parameter variation curve. It should be noted that the peak mean and trough mean can be calculated by summing the peak values ​​(or trough values) and then dividing by the number of peaks (or troughs), or an approximate value can be obtained by calculating the median method, which belongs to the conventional statistical method and will not be described in detail here.

[0034] The fluctuation ratio of the rock formation sequence in the target rock mass layer refers to the proportion of the fluctuation amplitude of the drilling parameter change curve corresponding to the rock formation sequence in the drilling parameter change curve corresponding to the target rock mass layer including the rock formation sequence and the weak interlayer sequence in the fluctuation amplitude of the drilling parameter change curve corresponding to the entire target rock mass layer (wherein the fluctuation amplitude refers to the variation amplitude of the fluctuation curve of a certain rock formation in the drilling parameter change curve); the number ratio of the rock formation sequence in the target rock mass layer refers to the ratio of the number of rock formations corresponding to the rock formation sequence in the target rock mass layer including the rock formation sequence and the weak interlayer sequence to the sum of the number of rock formations and the number of weak interlayers in the target rock mass layer.

[0035] Example 1

[0036] The method for determining formation integrity based on digital drilling of the present invention comprises the following steps:

[0037] Acquisition of drilling parameters: Drilling is performed using an impact drill equipped with a DPM system to collect drilling parameters during the drilling process. The drilling parameters during the drilling process are removed, and the drilling parameters during the drilling process such as empty pushing, drilling retreat, loosening of drill rods, and standby are removed to obtain the drilling parameters during the net drilling process.

[0038] Division of stratigraphic geological structure: Select the target rock mass layer from the results of stratigraphic geological structure division, and divide the different stratigraphic geological structures of the target rock mass layer based on the fluctuation of the while-drilling parameter change curve;

[0039] Based on the fluctuation of the drilling parameter variation curve, the different stratigraphic geological structures of the target rock layer are divided, specifically including: selecting the drilling parameter variation curve of the drilling speed V changing with the drilling depth D, and dividing the stratigraphic geological structure into several relatively stable fluctuation sections according to the changes in the peak and trough of the drilling speed V variation curve, among which the section with a sudden increase in the peak value and trough value in the drilling speed V variation curve is the section where the weak interlayer is located;

[0040] Drilling parameter value selection: Get n rock layer sequences S in the target rock layer n , m weak interlayer sequences W m ;

[0041] The specific division process of the above n rock sequence Sn and m weak interlayer sequence Wm can be seen in Figure 1 As shown, the rock layer sequence Sn is divided into 6 rock layers in total, and the weak interlayer sequence Wm is divided into 3 weak interlayers in total.

[0042] Numerical processing of drilling parameters: obtaining the rock formation sequence S n The corresponding thickness TS n , peak mean PS n , trough mean VS n The thickness corresponding to the rock sequence Sn is the depth corresponding to the interface where the drilling speed V change curve of each rock interface in the rock sequence Sn undergoes a mutation (the division method of the mutation interface adopts the conventional operation calibration method in the prior art, which will not be repeated here). The specific process of the peak mean and the trough mean corresponding to the rock sequence Sn can be seen Figure 2 The determination method shown is to make calibration lines according to the idea of ​​the median of the peak value (or trough value) to represent the peak mean (or trough mean); it is conceivable that the peak mean (or trough mean) can also be obtained by summing the values ​​and then taking the arithmetic mean. This calculation process belongs to the conventional calculation method in the prior art and will not be repeated here.

[0043] Similarly, the weak interlayer sequence W can be obtained in the same way. m The corresponding thickness TW m , peak mean PW m , trough mean VW m The specific process can be seen Figure 3 The determination method shown.

[0044] Example 2

[0045] The technical solution and data processing process of the present invention are described and explained in detail below in conjunction with a pumped storage power station project in Heilongjiang Province.

[0046] Table 1 Drilling speed parameters for target rock layers of a pumped storage power station in Heilongjiang Province

[0047]

[0048]

[0049] The first target rock mass layer has a total of 3 rock layer sequences S n is {S1, S2, S3}, a weak interlayer sequence {W1}, and the thickness TS corresponding to the rock sequence {S1, S2, S3} n The values ​​of the weak interlayer sequence W are {4.84, 2.51, 2.66}, the peak mean is {15.03, 14.90, 16.23}, and the trough mean is {6.24, 5.19, 6.76}. m The corresponding thickness {0.68}, peak mean PW m {23.27}, trough mean VW m {15.08}.

[0050] The statistical calculation results are shown in Tables 2 and 3.

[0051]

[0052] Determination of the evaluation factors of stratum integrity: Determination of the stratum sequence S n The fluctuation ratio f(S n ) and rock sequence S n The number ratio g(S n );

[0053] Rock sequence S n The fluctuation ratio f(S n ) is calculated as f(S n )=∑(TS n ×(PS n +VS n ))÷(∑(TS n ×(PS n +VS n ))+∑(TW m ×(PW m +VW m ))), rock sequence S n The number ratio g(S n ) is calculated as follows: g(S n )=n / (m+n).

[0054] TS1×(PS1+VS1)=102.91;

[0055] TS2×(PS2+VS2)=50.44;

[0056] TS3×(PS3+VS3)=61.14;

[0057] TW1×(PW1+VW1)=26.08;

[0058] ∑(TS n ×(PS n +VS n ))=214.48;

[0059] ∑(TW m ×(PW m +VW m ))=26.078;

[0060] Rock sequence S n The fluctuation ratio f(S n ) is calculated as f(S n )=0.89;

[0061] g(S n )=n / (m+n)=3 / (3+1))=3 / 4=0.75;

[0062] f(S n ) / g(S n )=0.89 / 0.75=1.19;

[0063] f(S n ) / g(S n ) reflects the strength of the formation integrity through numerical quantification. f(S n ) / g(S n ) value, the higher the degree of formation integrity.

[0064] Since the level of formation integrity reflects the relative level of formation integrity at different depths in the same area during the same drilling parameter analysis and processing, it does not require absolute numerical accuracy. Therefore, the number and size of the formation integrity thresholds can be set based on experience and actual project needs. Usually, a comprehensive judgment can be made based on the actual rock formation characteristics including rock type and rock uniaxial compressive strength obtained from regional geological surveys; in addition, it can also be verified and adjusted through rock drilling coring results.

[0065] According to the practical experience of project technicians in using digital drilling to judge rock stability, the formation integrity threshold sequence θ is set. i ={1, 1 / 3, 1 / 10} is a more reasonable and practical choice, that is, f(S n ) / g(S n )≥1, the formation integrity is level one; 1 / 3≤f(Sn ) / g(S n )<1, the formation integrity is level 2; 1 / 10≤f(S n ) / g(S n )<1 / 3, the formation integrity is level 3; f(S n ) / g(S n )<1 / 10, the formation integrity is level 4. The first target rock layer is located at the layer f(S n ) / g(S n )=1.19>1, so the formation integrity is level one, which belongs to the target rock layer with high formation integrity. In the same way, the second target rock layer f(S) within the depth range of 17.3-28.5m at this point is obtained. n ) / g(S n )=0.96, which is smaller than the first target rock layer f(S n ) / g(S n ), the stratum integrity is level 2. Therefore, under the same other conditions, the first target rock layer is preferred as the construction area for underground structures including underground powerhouses. n ) / g(S n ) Comparing the integrity and relative stability of strata at different depths in the same area is more scientific and reasonable than the usual evaluation method of the number of weak interlayers, and has achieved outstanding results.

[0066] At the same time, for strata with low stratigraphic integrity, their geological structure stability is relatively low, and the relevant areas and strata should be avoided during the early stage of project site selection.

[0067] Embodiment 3 is a computer-readable storage medium, wherein the computer-readable storage medium includes a stored computer program, wherein when the computer program is running, the device where the computer-readable storage medium is located is controlled to execute the method of the above-mentioned embodiment 1 or 2.

[0068] A computer device comprises a memory, a processor and a program stored and executable on the memory, wherein the program implements the steps of the method in the above-mentioned embodiment 1 or 2 when executed by the processor.

[0069] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When the use is implemented in whole or in part in the form of a computer program product, the computer program product includes one or more computer instructions. When the computer program instructions are loaded or executed on a computer, the process or function described in the embodiment of the present invention is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center). The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server, data center, etc. that contains one or more available media integrated. The available medium can be a magnetic medium (e.g., a floppy disk, a hard disk, a tape) or an optical medium.

[0070] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for determining formation integrity based on digital drilling, characterized in that: The following steps are involved: Step 1, acquisition of drilling parameters: using a drilling rig equipped with a DPM system to perform drilling, collecting drilling parameters during the drilling process of the drilling rig, performing data processing on the collected drilling parameters, and obtaining a change curve of the drilling parameters during the net drilling process; Step 2, stratigraphic geological structure division: select the target rock mass layer from the stratigraphic geological structure division result, and divide the different stratigraphic geological structures of the target rock mass layer based on the fluctuation of the while-drilling parameter change curve; Step 3: Selection and processing of drilling parameters: Obtain n rock layer sequences S in the target rock layer n , m weak interlayer sequences W m , and the rock sequence S n The corresponding thickness TS n , peak mean PS n , trough mean VS n , weak interlayer sequence W m The corresponding thickness TW m , peak mean PW m , trough mean VW m ; Step 4 Determination of the elements for evaluating the integrity of the formation: Determine the formation sequence S n The fluctuation ratio f(S n ) and rock sequence S n The number ratio g(S n ); Step 5: Setting the formation integrity threshold: Setting the formation integrity threshold sequence θ i ={θ1, θ2, ..., θ n }, where from θ1 to θ n The values ​​decrease in size; Step 6, formation integrity determination: f(S n ) / g(S n )≥θ1, the formation integrity is level one; θ2≤f(S n ) / g(S n )<θ1, the formation integrity is level 2; θ3≤f(S n ) / g(S n )<θ2, the formation integrity is level three; ...; and so on; wherein, the formation integrity gradually decreases from level one to level n+1; Step 7: Select a target rock layer with high stratum integrity as the construction area for underground structures including underground powerhouses.

2. The method for determining formation integrity based on digital drilling according to claim 1, characterized in that: The step 1 processes the collected while-drilling parameters to obtain a while-drilling parameter variation curve during the net drilling process, specifically including: removing the while-drilling parameter variation curve during the drilling rig empty push, drilling rig retreat, drill rod looseness, and standby process, and obtaining the while-drilling parameter variation curve of the while-drilling parameters changing with the drilling depth D during the net drilling process.

3. The method for determining formation integrity based on digital drilling according to claim 1, characterized in that: The step 2 is to divide different stratigraphic geological structures of the target rock mass layer based on the fluctuation of the drilling parameter variation curve, specifically including: selecting the drilling parameter variation curve of the drilling speed V changing with the drilling depth D, and dividing the stratigraphic geological structure into a number of relatively stable and fluctuating sections according to the changes in the peak and trough of the drilling speed V variation curve, wherein the section with a sudden increase in the peak value and trough value in the drilling speed V variation curve is the section where the weak interlayer is located.

4. The method for determining formation integrity based on digital drilling according to claim 1, characterized in that: In step 4, the rock sequence S n The fluctuation ratio f(S n ) is calculated as: f(S n )=∑(TS n ×(PS n +VS n ))÷(∑(TS n ×(PS n +VS n ))+∑(TW m ×(PW m +VW m ))), rock sequence S n The number ratio g(S n ) is calculated as follows: g(S n )=n / (m+n).

5. The method for determining formation integrity based on digital drilling according to claim 1, characterized in that: The step 5, setting the formation integrity threshold, specifically includes: according to practical experience and production conditions, or according to the formation sequence S n and the weak interlayer sequence W m The corresponding rock type, rock uniaxial compressive strength and other actual rock formation characteristics are comprehensively judged to set the formation integrity threshold sequence θ i The number of thresholds and the size of the thresholds.

6. The method for determining formation integrity based on digital drilling according to claim 1, characterized in that: In step 5, the formation integrity threshold sequence is set to θ i ={1, 1 / 3, 1 / 10}; In step 6, the method for determining the integrity of the formation is specifically: f(S n ) / g(S n )≥1, the formation integrity is level one; 1 / 3≤f(S n ) / g(S n )<1, the formation integrity is level 2; 1 / 10≤f(S n ) / g(S n )<1 / 3, the formation integrity is level 3; f(S n ) / g(S n )<1 / 10, the stratum integrity is level four.

7. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes a stored computer program, wherein when the computer program is executed, the device where the computer-readable storage medium is located is controlled to execute the method according to any one of claims 1 to 6.

8. A computer device, characterized in that: The computer device comprises a memory, a processor and a program stored and executable on the memory, and the program implements the steps of the method according to any one of claims 1 to 6 when executed by the processor.

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