Stratum integrity quantitative analysis method based on two-dimensional water tank physical simulation experiment

Abstract

The invention relates to a stratum integrity quantitative analysis method based on a two-dimensional water tank physical simulation experiment. According to the method, calculation of the stratum integrity is applied to the field of the water tank physical simulation experiment for the first time, meanwhile, quantitative analysis of the stratum integrity in the water tank physical simulation experiment can be achieved, and the deposition and denudation process of the stratum in the time dimension and the space dimension is accurately quantified. The method provided by the invention fills the blank in the technical field and promotes further development of sedimentary geology research and related engineering application.

Description

Technical Field

[0001] The present invention relates to the technical field of sedimentary geology, and particularly relates to a method for quantitatively analyzing the formation integrity based on a two-dimensional flume physical simulation experiment. Background Art

[0002] Most sedimentary strata record sedimentary breaks at different scales, showing incompleteness in terms of time and space. The formation integrity is defined as the ratio of the time T1 with sedimentary records to the total time T within a specific time range T (Sadler and Strauss, 1990). The research on "formation integrity" has always been a frontier field in international quantitative sedimentology and is of great research difficulty. Clearly and quantitatively characterizing "formation integrity" is of great significance for carrying out more accurate formation correlation, reconstructing the whole process of stratigraphic sedimentary evolution in geological periods, restoring sedimentary paleoenvironments and paleoclimates, and evaluating the development of high-quality reservoirs and guiding oil and gas exploration.

[0003] The flume physical simulation experiment can truly simulate geological processes such as clastic material erosion, transportation, deposition, and reworking (Straub et al., 2019), calculate the formation integrity at any position, and has unique advantages such as truly simulating autogenic sedimentation and complex random geological processes, small flume scale, short simulation time, facilitating high-precision full-process monitoring, and being easy to independently carry out single-factor analysis (Straub et al., 2020). However, at present, the research on formation integrity in flume physical simulation experiments is even scarcer, and in previous flume physical simulation tests, the quantitative analysis method for formation integrity is not yet perfect. Most studies can only qualitatively describe the macroscopic changes of the formation, lacking effective technologies for accurately quantifying the sedimentation and erosion processes of the formation in the time and space dimensions. Summary of the Invention

[0004] In view of the problems existing in the prior art, the present invention provides a method for quantitatively analyzing the formation integrity based on a two-dimensional flume physical simulation experiment, including the following steps:

[0005] S1 Conduct a two-dimensional flume physical simulation experiment and record the experimental process with a camera;

[0006] S2 Numericalization of experimental data:

[0007] S21 Export the experimental video file from the camera and extract pictures at fixed time intervals;

[0008] S22 Depict the distribution contour of the sediment in the extracted pictures in a drawing software and add coordinate axes, where the horizontal axis represents the length of the sediment body and the vertical axis represents the elevation value of the sediment body, both in centimeters;

[0009] S23 Use the WebPlotDigitizer software to extract equally spaced data from the processed pictures. The extracted data are two-dimensional coordinate points and are saved in the.csv format.

[0010] S24 Import all the.csv files into Sheet1 of the excel file.

[0011] S25 Subtract the sediment elevation value at the previous moment from the sediment elevation value at the next moment to obtain the sediment record comparison value. Judge the deposition or erosion state according to this comparison value and save the judgment result in Sheet2 of the excel file.

[0012] S26 Organize the data in Sheet2 of the excel file in step S25, and finally form three columns of data including time, length, and deposition / erosion state information, which are saved in Sheet3 of the excel file and saved as the.xyz file format separately.

[0013] S3 Import the.xyz format file saved in step S26 into the Petrel software, and use the two-dimensional conversion tool of the software to generate a planar picture with color identification from the.xyz file.

[0014] S4 Integrity calculation:

[0015] S41 Create a new Sheet4 in the excel file and copy the sorted data in Sheet2 in step S25 to Sheet4. Use the COUNTIF function to count the number of data points with values ≥0 in each interval.

[0016] S42 Calculate the ratio of the number of data points with values ≥0 in this column to the total number of data points in this column to obtain the integrity of this column.

[0017] S43 Calculate all the integrities in turn and generate a histogram.

[0018] On the basis of the above scheme, in step S1, before conducting the two-dimensional flume physical simulation experiment, first prepare experimental sands of different specifications and colors according to the requirements of the experimental design, and place an experimental slope in the transparent flume as the deposition bedform during the experiment. At the same time, select an appropriate source feeding speed and design the curve of the experimental water level changing with time.

[0019] Based on the above - mentioned solution, in step S1, during the experiment, the water level in the water tank rises and falls according to the designed water - level change curve over time. The total experimental time is M. When the experiment starts, first turn on the camera for recording, then turn on the water - level lifting device component to let the water level change over time, and then turn on the No. 1 material source feeder to release material source 1 at a predetermined flow rate. After running for m time, turn off the No. 1 material source feeder and turn on the No. 2 feeder to release material source 2. After running for another m time, turn off the No. 2 material source feeder and turn on the No. 1 feeder to release material source 1. Switch the material source feeder every m time to release different material sources until the experimental time M ends.

[0020] Based on the above - mentioned solution, in step S21, the fixed time interval is m.

[0021] Based on the above - mentioned solution, the drawing software is CorelDRAW, Adobe Illustrator, Shuanghu Geological Mapping System or Affinity Designer.

[0022] Based on the above - mentioned solution, the specific method of step S24 is: name the excel file as "**.xlsx", and import all.csv files into Sheet1. Among them, the horizontal axis represents the number of columns of the sediment body, the spacing is 1, and there are n columns of data in total. The abscissa from left to right is: 1, 1 + 1*1, 1 + 2*1, 1 + 3*1... 1+(n - 1)*1. The vertical axis represents time, from top to bottom in turn: 0, m, 2m, 3m... M; the middle data represents the elevation value of the sediment, and the unit is centimeters.

[0023] Based on the above - mentioned solution, the specific method of step S25 is: subtract the sediment elevation value of the previous moment from the sediment elevation value of the next moment to obtain the sediment record comparison value. Judge the sedimentation or erosion state according to this comparison value. Among them, a comparison value greater than 0 represents the sedimentation state, a comparison value less than 0 represents the erosion state, and a comparison value equal to 0 represents the sedimentation stagnation state, and save it in Sheet2 of the excel file;

[0024] Based on the above - mentioned solution, in step S3, in addition to Petrel software, Surfer software or Transform software can also be used.

[0025] The method of the present invention applies the calculation of formation integrity to the field of physical simulation experiments in water tanks for the first time. At the same time, the present invention can realize the quantitative analysis of formation integrity in physical simulation experiments in water tanks, and accurately quantifies the sedimentation and erosion processes of the formation in the time and space dimensions. The method of the present invention fills the gap in this technical field and promotes the further development of sedimentary geology research and related engineering applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of the two-dimensional flume physical simulation experiment equipment used in the present invention;

[0027] Figure 2 Conceptual schematic diagram of the water level change curve designed in step S13 in Embodiment 1 of the present invention;

[0028] Figure 3 Conceptual schematic diagram of the two-dimensional flume physical simulation experiment result in step S14 in Embodiment 1 of the present invention;

[0029] Figure 4 Conceptual schematic diagram of the processing of the two-dimensional flume physical simulation experiment result obtained in step S22 in Embodiment 1 of the present invention;

[0030] Figure 5 Conceptual schematic diagram of equally spaced sampling of the two-dimensional flume physical simulation experiment result in step S23 in Embodiment 1 of the present invention;

[0031] Figure 6 Graph of the water level change with time designed in step S13 in Embodiment 2 of the present invention;

[0032] Figure 7 Graph of the experimental result processing obtained in step S22 in Embodiment 2 of the present invention;

[0033] Figure 8 Sediment - erosion record graph obtained in step S31 in Embodiment 2 of the present invention;

[0034] Figure 9 Graph of the change of integrity with position in Embodiment 2 of the present invention. Detailed implementation manners

[0035] To further elaborate on the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation manners, structures, features and their effects of the present invention as follows.

[0036] Embodiment 1

[0037] The present invention provides a method for quantitatively analyzing the formation integrity based on a two-dimensional flume physical simulation experiment, and the method includes the following steps:

[0038] S1 Two-dimensional flume physical simulation experiment:

[0039] S11 Clean and horizontally place the transparent glass flume for the experiment (for example, with specifications of 1400mm × 500mm × 50mm) (the two-dimensional flume physical simulation experiment equipment is as Figure 1 shown, and the two-dimensional flume physical simulation experiment equipment used in the present invention itself belongs to the equipment in the prior art);

[0040] S12 Prepare experimental sands of different specifications and colors to ensure that the distribution of sediments can be visually observed. According to Figure 1 Connect the experimental device, and prepare an electronic watch for timing and a camera.

[0041] S13 Place the experimental slope as the sediment bottom form during the experiment. Select an appropriate feeding rate of the material source, and design the curve of the water level change over time for this experiment (as Figure 2 shown, h1 is the lowest point of the water level, h2 is the highest point of the water level, and t1, t2, t3, and t4 represent time points). Then set the parameters of the water level lifter assembly according to the designed curve, test the lifting assembly so that the experiment can rise and fall according to the predetermined curve of the water level change over time. Debug and calibrate each experimental device and connect them with silicone tubes. Horizontally install a camera in front of the experimental water tank to record the experimental process.

[0042] S14 The total experimental time is M. When the experiment starts, first turn on the camera for recording, turn on the water level lifter assembly to let the water level change over time, then turn on the No. 1 material source feeder to release material source 1 at a predetermined flow rate. After running for m time, turn off the No. 1 material source feeder and turn on the No. 2 feeder to release material source 2. After running for another m time, turn off the No. 2 material source feeder and turn on the No. 1 feeder to release material source 1. Switch the material source feeder every m time to release different material sources until the experiment ends at time M. During this period, continuously monitor the operation of the equipment and the progress of the experiment (the final result is as Figure 3 shown).

[0043] S2 Numericalization of experimental data:

[0044] S21 Export the experimental video file from the camera and extract pictures at fixed time intervals of m time to ensure that the extracted pictures can clearly and completely reflect the distribution characteristics of the sediments in the water tank.

[0045] S22 Then draw the distribution outline of the sediments in a drawing software (such as CorelDRAW, Adobe Illustrator, Shuanghu Geological Mapping System, Affinity Designer, etc.). Add coordinate axes (the horizontal axis represents the length of the sediment body, and the vertical axis represents the elevation value (thickness) of the sediment body, with the unit of both being centimeters), and then save it as a picture (as Figure 4 shown. The format of the picture can be.jpg,.png,.tif, etc.). Perform this operation on all the extracted pictures.

[0046] S23 Use the WebPlotDigitizer software to extract data at equal intervals (for example, the interval is 1, with the unit of centimeter) from the processed pictures. The extracted data are two-dimensional coordinate points (as Figure 5As shown, save it in the.csv format (such as "a1.csv", "a2.csv"... "ai.csv", where i is an integer greater than 0) for subsequent processing in Excel software;

[0047] S24 Name the excel file as "**.xlsx" (such as "Experiment.xlsx"), and import all.csv files into Sheet1 (the horizontal axis represents the number of columns of the sediment body, with a spacing of 1 and a total of n columns of data. The abscissa from left to right is: 1, 1 + 1*1, 1 + 2*1, 1 + 3*1... 1+(n - 1)*1, the vertical axis represents time, from top to bottom are: 0, m, 2m, 3m... M; the middle data represents the elevation value of the sediment, and the unit is centimeters, as shown in Table 1);

[0048] Table 1 - Schematic Concept Table for Experimental Data Sorting

[0049]

[0050] S25 Calculate the sediment record comparison value by writing a specific formula (subtracting the sediment elevation value of the previous moment from the sediment elevation value of the next moment, such as subtracting the sediment elevation value of the row where 3m is located from the sediment elevation value of the row where 2m is located), and judge the deposition or erosion state according to this comparison value (a comparison value greater than 0 represents the deposition state, a comparison value less than 0 represents the erosion state, and a comparison value equal to 0 represents the deposition stagnation state), and save it in Sheet2 of the excel file (as shown in Table 2);

[0051] Table 2 - Schematic Concept Table for Post - processing of Experimental Data

[0052]

[0053] S26 Sort out the data in Sheet2 of the excel file in step S25, and finally form three columns of data including time, length, and deposition / erosion state information, save it in Sheet3 of the excel file and save it as the.xyz file format (as shown in Table 3).

[0054] Table 3 - Schematic Concept Table in xyz Format

[0055]

[0056]

[0057] S3 Result Plotting:

[0058] S31 Import the saved.xyz format file in step S26 into Petrel software (in addition to Petrel software, software such as Surfer and Transform can also be used), and use the 2D conversion tool of Petrel software to generate a planar picture with color identification from the.xyz file;

[0059] The purpose of this step is to visually display the changes in the formation deposition / erosion / deposition stagnation state and provide accurate data visualization results for quantitative analysis of the formation deposition record.

[0060] S4 Integrity calculation:

[0061] S41 Based on the "Experiment.xlsx" file in step S2, create a new Sheet4 and copy the data sorted in Sheet2 in step S25 to Sheet4. Use the COUNTIF function to count the number of data points with a value ≥ 0 in each interval;

[0062] And calculate the ratio of the number of data points with a value ≥ 0 in this column to the total number of data points in this column to obtain the integrity of this column;

[0063] Calculate the integrity of all in turn and generate a histogram. The purpose of this step is to visually reflect the change of integrity with position.

[0064] Example 2

[0065] Based on the method in Example 1, the present invention provides a method for quantitative analysis of formation integrity based on a two-dimensional flume physical simulation experiment, including the following steps

[0066] S1 Preparations and operation procedures for the two-dimensional flume physical simulation experiment:

[0067] S11 Select a flume with a specification of 1400mm × 500mm × 50mm, clean it thoroughly to ensure no impurity residue, and use a horizontal calibration tool to place the flume accurately horizontally;

[0068] S12 Prepare quartz sands with 110 meshes and 120 meshes that have passed screening and inspection and have different colors (yellow and white) to ensure that the distribution of sediments can be visually observed. According to Figure 1 Connect all experimental equipment and prepare an electronic watch and a camera.

[0069] S13 Customize a bottom slope. The material of the bottom slope is polystyrene extruded board. The slope and length are cut according to experimental requirements, and it is carefully placed in the flume to ensure tight fitting and fixation to simulate real geological terrain conditions. Accurately correct the flow rates of the provenance component and the water circulation component to ensure the material addition speed (4.33×10-5 kg / s) and the water flow velocity (2.5×10 -6 m3 / s); design the curve of the water level changing with time for this experiment (as shown in Figure 6 ), set the parameters of the water circulation component according to the curve, including the lifting speed, amplitude, time interval, etc., and conduct multiple simulation tests to ensure that the water level can change stably according to the predetermined trajectory. Finally, horizontally install a camera in front of the experimental water tank to record the experimental process;

[0070] S14 The total experimental time is 570 minutes. When the experiment starts, first turn on the camera for recording, turn on the water level lifter component to let the water level change with time, then turn on the No. 1 source feeder to release source 1 at the predetermined flow rate. After running for 10 minutes, turn off the No. 1 source feeder and turn on the No. 2 feeder to release source 2. After running for another 10 minutes, turn off the No. 2 source feeder and turn on the No. 1 feeder to release source 1. Switch the source feeder to release different sources every 10 minutes, and repeat the switching operation until the experiment ends after 570 minutes. During this period, continuously monitor the operation of the equipment and the progress of the experiment.

[0071] S2 Experimental result processing:

[0072] S21 Export the experimental video file from the camera and extract pictures at fixed time intervals of N time to ensure that the extracted pictures can clearly and completely reflect the distribution characteristics of the sediment in the water tank;

[0073] S22 Then draw the distribution contour of the sediment in the CorelDRAW drawing software, add coordinate axes (the horizontal axis represents the length of the sediment body, and the vertical axis represents the thickness of the sediment body, with the unit being centimeters), and save it as a picture in the.jpg format (as shown in Figure 7 ), and perform this operation on all the extracted pictures;

[0074] S23 Use the WebPlotDigitizer software to extract data at equal intervals (interval of 1 cm) from the processed pictures. The extracted data are two-dimensional coordinate points, and save them in the.csv format for subsequent processing in the Excel software;

[0075] S24 Name the excel file as "Experiment.xlsx", and import all the.csv files into Sheet1 (the horizontal axis represents the number of columns of the sediment body, with an interval of 1 cm and a total of 127 columns of data. The abscissa is from left to right: 1, 2, 3,... 127); the vertical axis represents time, from top to bottom: 1, 2, 3... 57; the middle data represents the elevation of the sediment;

[0076] S25 Calculate the sediment record comparison value by subtracting the sediment elevation value at the previous moment from the sediment elevation value at the next moment, and judge the sedimentation or erosion state according to this comparison value (a comparison value greater than 0 represents the sedimentation state, a comparison value less than 0 represents the erosion state, and a comparison value equal to 0 represents the sedimentation stagnation state), and save it in Sheet2 of the file;

[0077] S26 Organize the data in Sheet2 of the excel file in step S25, and finally form three columns of data including time, length, and sedimentation / erosion state information, and save the organized data in Sheet2 as a.xyz file format.

[0078] S3 Result mapping:

[0079] S31 Import the.xyz format file saved in step S26 into the Petrel software, and use the two-dimensional conversion tool of the Petrel software to generate a planar picture with color identification (blue represents the sedimentation area, red represents the erosion area, and white represents the sedimentation stagnation area) from the.xyz file (as Figure 8 shown);

[0080] S32 The purpose of this step is to visually display the changes in the formation sedimentation / erosion / sedimentation stagnation state and provide accurate data visualization results for quantitative analysis of the formation sediment record.

[0081] S4 Integrity calculation:

[0082] S41 Based on the file "Experiment.xlsx" in step S2, create a new Sheet4 and copy the organized data in Sheet2 in step S25 to Sheet4, and use the COUNTIF function to count the number of data points with a value ≥ 0 at each interval;

[0083] S42 Calculate the ratio of the number of data points with a value ≥ 0 in this column to the total number of data points in this column, and the integrity of this column can be obtained;

[0084] S43 Calculate all the integrities in turn and generate a histogram. The purpose of this step is to visually reflect the change of integrity with position (as Figure 9 shown).

[0085] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to equivalent embodiments of equivalent changes within the scope of the technical solution of the present invention by using the technical content disclosed above. However, as long as it does not depart from the content of the technical solution of the present invention, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A quantitative analysis method of formation integrity based on a two-dimensional water tank physical simulation experiment, characterized in that: The steps include: S1 conducted a two-dimensional water tank physical simulation experiment and recorded the experimental process with a camera; S2 Experimental data digitization: S21 exports the experimental video file from the camera and extracts pictures at fixed time intervals; S22 uses the extracted images to draw the distribution outline of the sediment in the drawing software and adds coordinate axes, with the horizontal axis representing the length of the sediment body and the vertical axis representing the elevation value of the sediment body, both in centimeters; S23 uses WebPlotDigitizer software to extract equally spaced data from the processed images. The extracted data are two-dimensional coordinate points and saved in .csv format; S24 imports all .csv files into Sheet1 of the excel file; S25 uses the sediment elevation value at the next moment to subtract the sediment elevation value at the previous moment to obtain a sediment record comparison value, judges the deposition or erosion state according to the comparison value, and saves the judgment result in Sheet2 of the excel file; S26 sorts the data in Sheet 2 of the excel file in step S25, and finally forms three columns of data including time, length and deposition / erosion state information, and saves them in Sheet 3 of the excel file and also saves them in .xyz file format; S3 imports the .xyz format file saved in step S26 into the Petrel software, and uses the two-dimensional conversion tool of the software to generate a plane image with color identification from the .xyz file; S4 integrity calculation: S41 creates a new Sheet4 in the Excel file and copies the data sorted in Sheet2 in step S25 to Sheet4, and uses the COUNTIF function to count the number of data points with a value ≥ 0 in each interval; S42 calculates the ratio of the number of data points in the column whose values ​​are ≥ 0 to the total number of data points in the column, so as to obtain the integrity of the column; S43 calculates all the integrity in sequence and generates a histogram.

2. The formation integrity quantitative analysis method based on two-dimensional water tank physical simulation experiment according to claim 1 is characterized in that: In step S1, before conducting the two-dimensional water tank physical simulation experiment, prepare experimental sand of different specifications and colors according to the requirements of the experimental design, and place an experimental slope in a transparent water tank as the sedimentation bottom shape during the experiment. At the same time, select a suitable source feeding speed and design a curve of the experimental horizontal surface changing with time.

3. The quantitative analysis method of formation integrity based on two-dimensional water tank physical simulation experiment according to claim 2 is characterized in that: In step S1, during the experiment, the horizontal plane in the water tank is raised and lowered according to the designed curve of the horizontal plane changing with time; the total experiment time is M. When the experiment starts, first turn on the camera to record, turn on the water level lifter assembly to let the water level change with time, then turn on source feeder No. 1 to feed source 1 at a predetermined flow rate, after running for m time, turn off source feeder No. 1 and turn on feeder No. 2 to feed source 2, and after running for m time, turn off source feeder No. 2 and turn on feeder No. 1 to feed source 1, switch the source feeder to feed different sources every m time, until the experiment time M is over.

4. The formation integrity quantitative analysis method based on two-dimensional water tank physical simulation experiment according to claim 3 is characterized in that: In step S21, the fixed time interval is m.

5. The formation integrity quantitative analysis method based on two-dimensional water tank physical simulation experiment according to claim 1 is characterized in that: The drawing software is CorelDRAW, Adobe Illustrator, Shuanghu geological mapping system or AffinityDesigner.

6. The formation integrity quantitative analysis method based on two-dimensional water tank physical simulation experiment according to claim 1 is characterized in that: The specific method of step S24 is: name the excel file "**.xlsx", and import all .csv files into Sheet1, where the horizontal axis represents the number of columns of the sediment body, the spacing is 1, there are n columns of data, the horizontal axis from left to right is: 1, 1+1*1, 1+2*1, 1+3*1...1+(n-1)*1, the vertical axis represents time, from top to bottom is: 0, m, 2m, 3m...M; the data in the middle represents the elevation value of the sediment, the unit is centimeter.

7. The formation integrity quantitative analysis method based on two-dimensional water tank physical simulation experiment according to claim 6 is characterized in that: The specific method of step S25 is: use the sediment elevation value at the next moment to subtract the sediment elevation value at the previous moment to obtain the sediment record comparison value, and judge the deposition or erosion state according to the comparison value, wherein a comparison value greater than 0 represents a deposition state, a comparison value less than 0 represents an erosion state, and a comparison value equal to 0 represents a deposition stagnation state, which is saved in Sheet2 of the excel file.

8. The formation integrity quantitative analysis method based on two-dimensional water tank physical simulation experiment according to claim 1 is characterized in that: In step S3, in addition to Petrel software, Surfer software or Transform software can also be used.

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