Limestone aquifer fracture network construction method based on three-dimensional imaging technology and application

Abstract

The invention discloses a limestone aquifer fracture network construction method based on a three-dimensional imaging technology and application, and relates to the field of mine water disaster prevention and control. The method comprises the steps that firstly, holes are drilled in a coal seam top plate and a coal seam bottom plate, three-dimensional imaging equipment is placed in a drilled hole for data collection, and rock stratum crack information in the drilled hole is obtained and comprises the crack number, the crack trend, the crack width, the crack tendency, the crack length and the like; data acquisition of other drill holes is completed by using the same method; then optimizing the two-dimensional image through a computer, and carrying out statistical analysis on fracture information obtained by all drilled holes to obtain a fracture network of the whole mine; and finally, importing fracture information identified by the fracture network of the whole mine into three-dimensional modeling software, and constructing an aquifer fracture network model. According to the method, the fracture network in the limestone aquifer of the mine is constructed, so that the fractures are grouted, and the mine water disaster is prevented.

Description

Technical Field

[0001] The present invention relates to the field of mine water hazard prevention and control, and in particular to a method and application of constructing a limestone aquifer fracture network based on three-dimensional imaging technology. Background Art

[0002] How to mine coal safely, economically and efficiently is a difficult problem faced by coal mining enterprises. Coal mining is often accompanied by mine water hazards. Mine water hazards are one of the five major disasters in coal mines and seriously threaten the safe mining of mines. Grouting water blocking technology is to inject grouting materials into the aquifer through boreholes to transform the aquifer into a weak aquifer, or inject it into the water channel to cut off the supply of the source. Therefore, the scientificity and rationality of the grouting effect evaluation method are crucial to ensuring the safe mining of coal and the life and health of workers. The use of traditional rotary drilling technology to construct boreholes has technical problems such as low construction accuracy, slow construction speed, uncontrollable drilling trajectory, many invalid footages, low drilling utilization rate and poor grouting water blocking effect, which cannot meet the requirements of mine water prevention and control. Directional drilling technology in underground coal mines can realize the precise control of the drilling trajectory, ensure the effective extension of the drilling trajectory in the predetermined position, increase the water blocking amount of a single borehole, and greatly improve the efficiency of mine water hazard prevention and control. However, the prerequisite for directional drilling and grouting is to clearly identify the location of the fractures in the coal mine, construct a regional fracture network, and achieve preliminary visualization of the grouting.

[0003] At present, the technology for constructing underground fracture networks is relatively immature. The traditional fracture measurement method in my country is to use drilling coring, and use drilling machinery and technology to drill underground rock formations, and take out core samples to study and analyze underground geological conditions. However, drilling coring has the following shortcomings: First, it is time-consuming. Coring requires special drilling tools, which affects the drilling progress, and it is impossible to achieve a 100% drilling coring rate, and the cost is high; second, after the rock sample is taken out of the borehole, the core will lose its original position and original state information, and at the same time lose the data such as the structure, fracture and occurrence of the rock sample in the borehole; third, the coring of the borehole is discontinuous, and it is impossible to judge the changes in the drilling trajectory based on the core; fourth, it is impossible to perceive the development of fractures, veins and caves in the borehole, etc. Therefore, it is urgent to study a new method to measure underground fractures and construct a fracture network.

[0004] This shows that the prior art needs to be further improved. Summary of the invention

[0005] The purpose of the present invention is to provide a method for constructing a fracture network of a limestone aquifer based on three-dimensional imaging technology, which uses a high-definition camera to detect the fracture structure inside the borehole, synthesizes the two-dimensional information read by the high-definition camera into a three-dimensional image through computer processing, and constructs the fracture network in the limestone aquifer in the mine, so as to grout the fractures and prevent the occurrence of mine water hazards.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A method for constructing a limestone aquifer fracture network based on three-dimensional imaging technology comprises the following steps:

[0008] S1. Combining theoretical knowledge, several drilling areas are arranged on the roof and floor of the coal seam, and a drilling machine is used to drill holes into the limestone aquifer in each drilling area to obtain several boreholes;

[0009] S2, arranging a three-dimensional imaging device in each borehole to collect data, and obtaining the rock formation fracture information in the borehole; transmitting the rock formation fracture information to the imaging device host;

[0010] S3, extracting and processing the rock formation crack information through the imaging device host to obtain a two-dimensional image, and analyzing the direction of the cracks in the two-dimensional image;

[0011] S4, sorting and grouping the raw data obtained from all the drillings, and using a computer to calculate the distribution form of each group of rock formation fracture information;

[0012] S5. Statistically analyze the fracture information obtained from all the drillings to obtain the fracture network of the entire mine;

[0013] S6. Import the fracture information identified from the fracture network of the entire mine into the 3D modeling software, perform spatial positioning according to the actual coordinates, and construct an aquifer fracture network model based on the geometric parameters and spatial position relationship of the fractures.

[0014] In the above-mentioned method for constructing a limestone aquifer fracture network based on three-dimensional imaging technology, in step S2, the three-dimensional imaging equipment includes a 360° high-definition camera and a cable. The 360° high-definition camera is used to shoot and record the rock formation fracture information in the borehole, and the collected information is transmitted to the imaging device host through the cable.

[0015] The above-mentioned method for constructing a limestone aquifer fracture network based on three-dimensional imaging technology, the 360° high-definition camera includes a high-definition probe, and the rock formation fracture information is obtained by rotating the high-definition probe 360°; the rock formation fracture information mainly includes the number of fractures, fracture direction, fracture width, fracture inclination and fracture length.

[0016] In the above-mentioned method for constructing a fracture network of a limestone aquifer based on three-dimensional imaging technology, in step S3, the two-dimensional image is enhanced by image processing software to make the fracture structure in the two-dimensional image clearer; and an edge detection image recognition algorithm or a threshold segmentation image recognition algorithm is used to automatically identify and extract fracture information in the two-dimensional image.

[0017] In the above-mentioned method for constructing a fracture network of a limestone aquifer based on three-dimensional imaging technology, in step S4, the distribution form is in the form of mean and standard deviation.

[0018] In the above-mentioned method for constructing a fracture network of a limestone aquifer based on three-dimensional imaging technology, in step S5, the Monte Carlo method is used for statistical analysis.

[0019] In the above-mentioned method for constructing a limestone aquifer fracture network based on three-dimensional imaging technology, in step S6, the aquifer fracture network model is optimized and adjusted to improve the prediction ability and practicality of the aquifer fracture network model.

[0020] The above-mentioned method for constructing a limestone aquifer fracture network based on three-dimensional imaging technology determines the main parameters that have a great impact on the results of the aquifer fracture network model by performing sensitivity analysis on the parameters of the aquifer fracture network model, and optimizes and adjusts the aquifer fracture network model by analyzing the main parameters.

[0021] In the above-mentioned method for constructing a limestone aquifer fracture network based on three-dimensional imaging technology, in step S1, several drilling areas are arranged on the roof and floor of the coal seam in combination with the mine topography, geological conditions, and the location of the aquifer.

[0022] Another object of the present invention is to provide the application of the above-mentioned method for constructing a limestone aquifer fracture network based on three-dimensional imaging technology in the fields of coal mining, underground excavation, tunnel construction or geological exploration.

[0023] Compared with the prior art, the present invention brings the following beneficial technical effects:

[0024] The present invention proposes a method for constructing a limestone aquifer fracture network based on three-dimensional imaging technology, which uses three-dimensional imaging equipment to collect data to obtain rock fracture information in the borehole, including the number of fractures, fracture direction, fracture width, fracture tendency and fracture length, etc.; then the same method is used to complete data collection for other boreholes; then the two-dimensional image is optimized and processed by computer, and the fracture information obtained from all boreholes is statistically analyzed to obtain the fracture network of the entire mine; finally, the fracture information identified from the fracture network of the entire mine is imported into three-dimensional modeling software to construct an aquifer fracture network model.

[0025] By adopting the method of the present invention, directional drilling and grouting in coal mines can be guided to achieve groundwater management in the mine aquifer and prevent groundwater from flowing into the mine and causing mine water damage. The use of three-dimensional imaging technology can not only improve the accuracy and reliability of mine measurement, but also improve the automation and intelligence level of mine measurement work, which is of great significance for improving mine safety monitoring and scene roaming functions. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention will be further described below in conjunction with the accompanying drawings:

[0027] Figure 1 It is a schematic diagram of collecting rock fracture information using three-dimensional imaging equipment in the present invention;

[0028] Figure 2 A flow chart for constructing a limestone aquifer fracture network based on three-dimensional imaging technology in the present invention;

[0029] Figure 3 This is an information diagram of a branch hole collected in Example 1 of the present invention;

[0030] Figure 4 This is a crack information diagram of a certain section of a branch hole after being processed by Example 1 of the present invention;

[0031] Figure 5 This is a schematic diagram of the fracture network of a portion of Example 1 of the present invention. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0033] In the description of this application, unless otherwise specified, " / " means "or", for example, A / B can mean A or B. "And / or" in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusions.

[0034] The technical solution of the present application is further described in detail below in conjunction with the accompanying drawings.

[0035] The main technical concept of the present invention is: first, drill a hole in the roof and floor of the coal seam; after the drilling is completed, use a three-dimensional imaging device to take real-time photos inside the borehole and transmit the photographed data to the imaging device host of the three-dimensional imaging device through a transmission cable, extract and process the fracture information inside the borehole, automatically generate a 360° full-hole wall profile and a 3D core column diagram, and jointly process and analyze multiple groups of measurement images to obtain the fracture network in the limestone aquifer. According to the specific fracture network, the directional drilling and grouting in the coal mine is guided, so as to achieve the management of groundwater in the mine aquifer and prevent the occurrence of mine water disasters caused by groundwater influx into the mine.

[0036] The three-dimensional imaging device described in the present invention specifically includes an imaging device host, a probe, a cable, a winch, a wheel hub, a stepping motor, a depth counter and a tripod.

[0037] Among them, the imaging device host is used for storing and processing image stitching, video, depth, azimuth and other information.

[0038] Probe: Used to take pictures and videos, record the azimuth angle of the well, and transmit the information to the imager host via cable.

[0039] Cable: connects the probe and the imager host to transmit the internal information of the borehole.

[0040] Winch: used to control the lifting and lowering of the probe.

[0041] Hub: Cooperate with the stepper motor to control the uniform lowering and lifting of the probe.

[0042] Stepper motor: used to precisely control the raising and lowering speed of the probe.

[0043] Depth counter: records the depth of the probe in the well.

[0044] Tripod: Located at the top of the drill hole, it provides stable support for the equipment in the drill hole.

[0045] The specific method of using the above-mentioned three-dimensional imaging device can be realized by those skilled in the art by referring to the existing technology, and will not be described in detail herein.

[0046] Combination Figure 1 and Figure 2 As shown, the present invention provides a method for constructing a limestone aquifer fracture network based on three-dimensional imaging technology, comprising the following steps:

[0047] (1) Several drilling areas are arranged on the roof and floor of the coal seam in combination with the mine topography, geological conditions, and the location of the aquifer. In each drilling area, a drilling machine is used to drill holes into the limestone aquifer to obtain several boreholes.

[0048] Furthermore, the drilling method in this step adopts the drilling method commonly used in the prior art to perform drilling.

[0049] (2) The above-mentioned three-dimensional imaging device is arranged in each borehole to collect data and obtain the rock formation fracture information in the borehole; and the rock formation fracture information is transmitted to the imaging device host.

[0050] In the above steps, a 360° high-definition camera is used to shoot and record the rock formation crack information in the borehole, and the collected information is transmitted to the imaging device host through a cable. The rock formation crack information mainly includes the number of cracks, crack direction, crack width, crack tendency and crack length.

[0051] (3) The rock formation fracture information is extracted and processed by the imaging device host to obtain a two-dimensional image, and the direction of the fractures in the two-dimensional image is analyzed; the two-dimensional image is enhanced by image processing software to make the fracture structure in the two-dimensional image clearer; and the edge detection image recognition algorithm or the threshold segmentation image recognition algorithm is used to automatically identify and extract the fracture information in the two-dimensional image.

[0052] (4) The raw data obtained from all the drillings are sorted and grouped, and the distribution form (mean and standard deviation) of each group of rock formation fracture information is calculated using a computer.

[0053] (5) Statistically analyze the fracture information obtained from all the boreholes to obtain the fracture network of the entire mine;

[0054] (6) Import the identified fracture information into GIS (Geographic Information System) or 3D modeling software and perform spatial positioning according to the actual coordinates. Construct an aquifer fracture network model based on the geometric parameters and spatial position relationship of the fractures, taking into account the connectivity and cross-relationships between fractures.

[0055] The accuracy and reliability of the fracture network model are verified by comparing it with other geological exploration methods (such as drilling data and hydrogeological tests). A sensitivity analysis is performed on the model parameters to determine the key parameters that have a greater impact on the model results. Based on the verification results and sensitivity analysis, the model is optimized and adjusted as necessary to improve the predictive ability and practicality of the aquifer fracture network model.

[0056] The present invention will be further described below in conjunction with specific embodiments:

[0057] Embodiment 1:

[0058] Shandong Qiuji Coal Mine Co., Ltd. is located in Qihe County, Dezhou City, and is affiliated to Shandong Energy Xinwen Mining Group Co., Ltd. The unit water inflow is 0.1422~0.96L / s·m, and the water-richness is medium. The aquifers that affect the mine production in the mine field are mainly bottom conglomerate, wind oxidation zone, Taiyuan Group 1st ash, 2nd ash, 3rd ash, , Xu ash and Ordovician limestone aquifers from top to bottom. The thickness of the 4th ash is 3.60~7.30m, with an average of 5.78m; the thickness of the 5th ash is 0.66~3.75m, with an average of 2.10m. The average spacing of the 4th and 5th ash is 1.37m, which can be regarded as an aquifer, commonly known as the 4th and 5th ash, which is the direct water-filled aquifer for mining the 11th coal seam. After the coal seam is mined, dense and long-extending mining fissures are formed in the roof and floor rock strata, and the groundwater in the 4th and 5th ash will enter the mine along the mining fissures. This example is to detect the fracture network between the four-five ash and the coal seam, which is used to guide the directional grouting of the mine to prevent water from the aquifer from entering the mine. The specific implementation steps are as follows;

[0059] (1) According to the geological report of Qiuji Coal Mine, 2 groups of 20 branch holes were arranged in the roof 45 ash aquifer. According to the height of the drilling platform on site and combined with the engineering design, the ZJ-30 drilling rig and the corresponding drilling tools were used in the drilling process. The first section of the group was drilled with a Φ311 roller drill bit, and the second section was drilled with a Φ216PDC drill bit. The MWD wireless inclinometer was used for directional drilling in the first and second sections of the full borehole, and the wellbore trajectory was accurately controlled, and geological guidance was carried out in conjunction with drilling logging, cuttings logging and other methods.

[0060] (2) After the drilling is completed, first assemble the winch, wheel hub, stepper motor, depth counter and other equipment, install the tripod at the hole mouth, and then connect the probe to the imager and various equipment. After checking that all equipment is OK, put the probe into the No. 1 branch hole of the No. 37 hole group. Then record the crack information in the borehole and store the obtained information in the host. After the No. 1 branch hole is collected, install the equipment to collect data in the No. 2 branch hole, and so on to collect all the information of the 20 boreholes. Figure 3 This is an information diagram of a branch hole collected.

[0061] (3) Expand the borehole information map scanned by the probe into a two-dimensional image, and use the imaging device host to remove the redundant information in the image, leaving only the relevant crack information. The image is processed to make the crack information more obvious. Finally, the crack information in the two-dimensional image is identified and extracted. Figure 4 This is the fracture information diagram of a certain section of a branch hole after processing.

[0062] (4) The information obtained in the previous step is grouped according to hole groups and branch holes, with each branch hole as a group, for a total of 20. The distribution form of each group of rock formation fracture information is calculated. The information with excessive errors is optimized.

[0063] (5) Perform statistical analysis on all the information to obtain the fracture network of the entire mine.

[0064] (6) The obtained fracture network is constructed by three-dimensional modeling software and compared with the geological data of Qiuji Coal Mine. The fracture network constructed by this method is almost the same as the actual measured data and can be used to guide the directional grouting work of aquifers. Figure 5 Schematic diagram of a part of the fracture network.

[0065] (7) Under the guidance of the fracture network diagram, directional grouting was carried out on the 45-ash aquifer. After grouting, the water inflow of Qiuji Coal Mine was significantly reduced.

[0066] The present invention applies three-dimensional imaging technology to the construction of aquifer fracture networks, which can effectively solve the problem of being unable to determine fractures during drilling and grouting. In addition, the method of the present invention is not only used in the field of coal mining, but also in underground excavation, tunnel construction and geological exploration.

[0067] Parts not described in the present invention can be implemented by referring to the existing technology.

[0068] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present application and are not intended to be limiting of the present application. As long as they are within the spirit and scope of the present application, appropriate changes and modifications to the above embodiments are within the scope of protection claimed in the present application.

Claims

1. A method for constructing a limestone aquifer fracture network based on three-dimensional imaging technology, characterized in that: The following steps are involved: S1. Combining theoretical knowledge, several drilling areas are arranged on the roof and floor of the coal seam, and a drilling machine is used to drill holes into the limestone aquifer in each drilling area to obtain several boreholes; S2, arranging a three-dimensional imaging device in each borehole to collect data, and obtaining the rock formation fracture information in the borehole; transmitting the rock formation fracture information to the imaging device host; S3, extracting and processing the rock formation crack information through the imaging device host to obtain a two-dimensional image, and analyzing the direction of the cracks in the two-dimensional image; S4, sorting and grouping the raw data obtained from all the drillings, and using a computer to calculate the distribution form of each group of rock formation fracture information; S5. Statistically analyze the fracture information obtained from all the drillings to obtain the fracture network of the entire mine; S6. Import the fracture information identified from the fracture network of the entire mine into the 3D modeling software, perform spatial positioning according to the actual coordinates, and construct an aquifer fracture network model based on the geometric parameters and spatial position relationship of the fractures.

2. The method for constructing a limestone aquifer fracture network based on three-dimensional imaging technology according to claim 1, characterized in that: In step S2, the three-dimensional imaging device includes a 360° high-definition camera and a cable. The 360° high-definition camera is used to shoot and record the rock fracture information in the borehole, and the collected information is transmitted to the imaging device host through the cable.

3. The method for constructing a limestone aquifer fracture network based on three-dimensional imaging technology according to claim 2, characterized in that: The 360° high-definition camera includes a high-definition probe, and the rock formation crack information is obtained by rotating the high-definition probe 360°; the rock formation crack information mainly includes the number of cracks, crack direction, crack width, crack inclination and crack length.

4. The method for constructing a limestone aquifer fracture network based on three-dimensional imaging technology according to claim 1, characterized in that: In step S3, the two-dimensional image is enhanced by image processing software to make the crack structure in the two-dimensional image clearer; an edge detection image recognition algorithm or a threshold segmentation image recognition algorithm is used to automatically identify and extract the crack information in the two-dimensional image.

5. The method for constructing a limestone aquifer fracture network based on three-dimensional imaging technology according to claim 1, characterized in that: In step S4, the distribution form is in the form of mean and standard deviation.

6. The method for constructing a limestone aquifer fracture network based on three-dimensional imaging technology according to claim 1, characterized in that: In step S5, the Monte Carlo method is used for statistical analysis.

7. The method for constructing a limestone aquifer fracture network based on three-dimensional imaging technology according to claim 1, characterized in that: In step S6, the aquifer fracture network model is optimized and adjusted to improve the prediction capability and practicability of the aquifer fracture network model.

8. The method for constructing a limestone aquifer fracture network based on three-dimensional imaging technology according to claim 7, characterized in that: By performing sensitivity analysis on the parameters of the aquifer fracture network model, the main parameters that have a great influence on the results of the aquifer fracture network model are determined, and the optimization and adjustment of the aquifer fracture network model are achieved by analyzing the main parameters.

9. The method for constructing a limestone aquifer fracture network based on three-dimensional imaging technology according to claim 1, characterized in that: In step S1, several drilling areas are arranged on the roof and floor of the coal seam in combination with the mine topography, geological conditions and the location of the aquifer.

10. Application of the method for constructing a limestone aquifer fracture network based on three-dimensional imaging technology according to any one of claims 1 to 9 in the fields of coal mining, underground excavation, tunnel construction or geological exploration.

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