CN116378760A - North China type coal field collapse column exploration and evaluation method based on ground directional drilling technology - Google Patents
North China type coal field collapse column exploration and evaluation method based on ground directional drilling technology Download PDFInfo
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Abstract
The invention discloses a north China coal field collapse column exploration and evaluation method based on a ground directional drilling technology, which comprises the following steps: determining the central position of a three-dimensional seismic delineation collapse column on a contour diagram of a coal seam floor as the opening position of a main exploration hole; determining the number, the azimuth and the horizontal displacement of the directional branch holes detected by the collapse column; calculating the distance between the coal bed bottom plate and the Ort ash water-bearing layer, and the water head height of the Ort ash water-bearing layer; calculating the thickness M of a safe water-resisting layer of the coal seam bottom plate; calculating the final hole depth of the main hole and the final hole elevation of the branch hole detected by the collapse column; determining the deflecting radius and track of the branch hole; performing main hole construction, judging the top boundary position of the collapse column according to the rock core, and performing hydrogeological test; constructing branch holes, judging the upper interface and the side interface of the collapse column, and performing hydrogeologic tests; and (3) defining the space morphology of the collapse column, and analyzing and evaluating the water enrichment and water conductivity of the collapse column. The invention provides scientific basis for stope and mine control water design, and ensures safe and efficient production of mines.
Description
Technical Field
The invention relates to the technical field of collapse column exploration. In particular to a north China coal field collapse column exploration and evaluation method based on a ground directional drilling technology.
Background
The North China has wider distribution in the North China, the mountain is in the shade from the north, the mountain is in the south to the Qin mountain, the mountain is in the Dabie mountain, the mountain is in the West mountain, and the eastern mountain reaches the sea; including all 5 provinces such as Hebei, shanxi, henan, beijing, tianjin, etc., the south of 3 provinces such as Jilin, liaoning, inner Mongolia, etc., the middle and west of Shandong provinces, the northwest of Jiangsu provinces, the north of Anhui, shanxi provinces and the eastern of Gansu and Ningxia provinces, the total area is about 15 ten thousand km 2 . North China coal field is a carboloy-binary coal field, the coal-based stratum base is huge thick Ortse limestone, and the Ortse limestone is in pseudo-integrated contact with the overlying stratum, so that the Ortse limestone is commonly lostSystem, aspiration system, clay basin system and stone-discharging carbon system. The rock-karst of the well-Ort Tao Tongma ditch group causes great water burst threat to coal seam exploitation due to high water pressure and large water quantity.
The karst collapse column is a geological phenomenon with extremely rich regional characteristics of extensive development of North China coal fields, and is a columnar collapse body formed by continuously collapsing an overburden layer downwards due to the fact that a coal-based stratum substrate is thick in a layer of easily soluble limestone, and under the strong corrosion and mechanical action, a large karst cave is formed and the jacking force on the overburden layer is lost. The karst collapse columns are widely developed and distributed in North China coal fields, and the size of the collapse columns can reach 500m in height and 10-200 m in diameter. The existence of the collapse column not only damages the stability and continuity of the coal seam, but also reduces the reserves of coal resources and the loss of a large amount of coal resources; meanwhile, the existence of the collapse columns also influences the conventional arrangement of the working face, reduces the use efficiency of the fully mechanized mining machinery, brings great adverse effects to the safe production of the coal mine, and reduces the economic benefit of the coal mine. If the water guiding collapse column is not probed to a sufficient degree, mine water burst possibly occurs, heavy accidents such as well flooding and the like are caused, and the safety production of the coal mine is greatly threatened. Because the karst collapse column is one of the main channels of karst groundwater activity, it often communicates with the main aquifer, and introduces the Ore limestone water into the mine, resulting in a flooding water hazard. Therefore, how to find out the scale and water conductivity of the collapse columns in the production mining area by adopting an effective technical method has great significance in providing effective technical guarantee for the safe production of coal mines. In production practice, it is proved that the exploration means of combining geophysical exploration and drilling is the guarantee of effectively finding out the collapse column by adopting 'geophysical exploration in advance'.
Any geophysical prospecting method is to explain the differences of certain physical characteristic parameters (such as gravity, electric parameters, magnetic parameters, seismic wave parameters and the like), so that various methods have advantages, disadvantages and application ranges. Practice proves that the comprehensive geophysical prospecting technology method is adopted for comprehensive interpretation and analysis, various technical achievements are mutually verified, the aim of getting the best of the invention is achieved, and the method is an effective method for improving the reliability and the accuracy of geophysical prospecting data interpretation achievements. Three-dimensional earthquake and transient electromagnetic methods are common geophysical prospecting methods for coal fields. Three-dimensional seismic exploration techniques are relatively sensitive to the structural (fault, trap column, etc.) reflection of coal fields, while transient electromagnetic methods are relatively sensitive to the conditions of water content within the structure. The three-dimensional seismic exploration and transient electromagnetic method are comprehensively applied, and the method is an effective means for exploring occurrence, structure and solving hydrogeology problems of coal seams in coal mines.
As the collapse column is an isolated geologic body, the detection method has the characteristics of irregular space morphology (the projection of the collapse column on a horizontal plane or a contour diagram of a coal seam floor is generally elliptical, circular, strip-shaped and the like), different sizes, different heights, strong concealment and the like, and the detection technology of the collapse column is more difficult. Three-dimensional seismic exploration technology is introduced at the end of the twentieth eighties of the North China coal field, and the three-dimensional seismic exploration technology is adopted for coal mines, so that the design, data acquisition, data processing and data interpretation of an observation system are greatly improved, but the prediction of construction interpretation results and coal seam thickness are not suitable for the control precision required by coal mine production due to the influence of various factors such as geophysical prospecting instrument precision, geological conditions (such as topography fluctuation, thickness of an overlying loose layer, inclination angle change of a coal-based stratum, construction complexity and the like), data processing software performance and experience of data interpretation personnel. According to incomplete statistics of coal mine exploration comparison results, the accuracy of explanation of the three-dimensional earthquake technology on collapse columns with the diameters of the long axes being more than 25m is only 40% -50% at present. The transient electromagnetic detection result mainly reflects the volume effect, so that the collapse column, the water enrichment property and the like can be only qualitatively explained, and the interpretation accuracy is low. Therefore, it is necessary to develop a method for exploration and evaluation of the collapse columns of the North China coal field based on the ground directional drilling technology, so as to improve the accuracy of interpretation of the collapse columns with the long axis diameter of more than 25 m.
Disclosure of Invention
Therefore, the technical problem to be solved by the invention is to provide a north China coal field collapse column exploration and evaluation method based on a ground directional drilling technology, so as to solve the problem that the existing collapse column exploration and evaluation method has low interpretation accuracy for collapse columns with the long axis diameter of more than 25 m.
In order to solve the technical problems, the invention provides the following technical scheme:
the North China coal field collapse column exploration and evaluation method based on the ground directional drilling technology comprises the following steps of:
(1) Utilizing the extending distribution of a three-dimensional seismic exploration delineating Collapse column (Collapse column) on a contour diagram of a bottom plate of a recoverable Coal seam (Coal seam), determining a central position point O (x, y, z) of the Collapse column on the contour diagram of the bottom plate of the recoverable Coal seam, and determining the opening position of a Main exploration hole according to the central position point;
(2) Determining the number of directional Branch holes (Branch holes) of the collapse column, and determining the horizontal projection azimuth and horizontal displacement (or horizontal length) of the directional Branch holes;
(3) Analyzing and calculating to determine the distance between the bottom plate of the coal bed and the aquifer of the Ore limestone (Ore for short) near the collapse column and the water head height of the Ore limestone aquifer;
(4) Determining a critical water inrush coefficient, and calculating the thickness M of a safe water-resisting layer of a coal seam floor;
(5) Calculating the final hole depth of the main hole of the collapse column exploration, and determining the final hole elevation (Final hole elevation) of each directional branch hole;
(6) Determining the deflecting radius or dog leg angle (Dogleg angle) of a deflecting section of the directional branch hole, and designing the track (including sidetrack elevation, final hole elevation and the like) of each directional branch drilling hole;
(7) Constructing a main hole, drilling and coring the main hole, judging the top boundary position of the collapse column according to the rock core, and performing a hydrogeological test on the collapse column section;
(8) Constructing a directional branch hole, judging the upper interface and the side interface of the collapse column, and carrying out hydrogeological test on the collapse column section;
(9) Determining the actual space form of the collapse column from M depth below the coal bed bottom plate to the top boundary of the collapse column according to the determined top boundary position of the collapse column, the upper boundary and the boundary of the collapse column, and comparing and analyzing with the position of the collapse column defined by the three-dimensional seismic exploration; and analyzing and evaluating the water enrichment and water conductivity of the collapse column and the water inrush danger of mining of surrounding coal beds according to the result of the hydrogeological test.
The method utilizes the ground directional drilling technology and the drilling hydrogeological test (water pumping test or water injection test and pressurized water test) to probe and evaluate the North China coal field collapse column, and further finds out the space form, the water enrichment property and the water conductivity of the collapse column on the basis of determining the abnormal area range of the collapse column by the geophysical prospecting circle, thereby avoiding the water bursting risk of underground drilling construction and providing scientific basis for the design of stope and mine prevention and control water.
In the method for exploring and evaluating the north China coal field collapse column based on the ground directional drilling technology, in the step (1), the opening position of the main exploration hole is the projection point of the point O (x, y, z) of the center position of the collapse column defined by the three-dimensional seismic exploration on the ground; probing the main hole as a vertical hole;
in the step (2), the number of the directional branch holes and the azimuth and horizontal displacement (or horizontal length) of the horizontal projection of the directional branch holes are determined according to the extension range of the three-dimensional seismic exploration trap column on the contour diagram of the bottom plate of the shearable layer; the number of the directional branch holes is 4-8; each directional branch hole is formed by sidetrack drilling of a main probing hole; the horizontal projection length of the directional branch hole exceeds the projection boundary of the collapse column on the coal seam floor by 10-20 m;
the calculation formula of the horizontal displacement (Horizontal displacement) of each directional branch hole is as follows:
in the formula (1): h i -horizontal displacement of the directional branch hole (i=1, 2,3 … …), m;
l-directional branch hole exceeding
Length, m; taking 10-20;
in the invention, for a collapse column with the major axis diameter smaller than 100m, taking the plane projection center point as the open position of a main hole on the ground, laterally drilling 4 directional branch holes at a certain depth section of the main hole, wherein the horizontal projections of the 4 directional branch holes are respectively in the major axis direction and the minor axis direction; for a near-elliptical collapse column with the major axis diameter larger than 100m, taking the plane projection center point as the position of the main hole for exploring the hole opening of the ground, laterally drilling 8 directional branch drilling holes at a certain depth section of the main hole, taking the major axis direction with the horizontal plane projection included angle smaller than 90 degrees with the north direction as the direction of the first branch hole, and designing one directional branch hole every 45 degrees in the clockwise (or anticlockwise) direction; for a collapse column with the long axis diameter larger than 100m and irregular shape, the number of directional branch holes is designed according to the plane projection shape of the collapse column, so that the projection intervals of the positions of adjacent directional branches Kong Zhongkong on the horizontal plane are basically equal;
in the step (3), the distance between a normal shearable layer bottom plate and an underlying Otto limestone aquifer near a collapse column and the Otto aquifer water head height at the center position of the collapse column are calculated according to the hydrogeological data of the coal mine; the estimation method comprises the following steps: (1) the distance between the normal coal seam floor and the underlying Otto limestone aquifer near the collapse column can be calculated by adopting an interpolation method (or extrapolation method) according to the coordinates of each drilling hole near the collapse column and the distance between the coal seam floor and the Otto limestone aquifer at each drilling hole, drawing a contour map of the distance between the coal seam floor and the Otto aquifer on the basis of a contour map of the coal seam floor; (2) the water head height of the Ore aquifer at the center of the collapse column can be obtained by drawing a water level contour diagram of the Ore aquifer on the basis of a contour diagram of a coal seam bottom plate and calculating by adopting an interpolation method (or extrapolation method);
the coal mine geology and hydrogeology data comprise a coal seam bottom plate contour map, a drilling histogram, a mine water filling map, an Olympic ash contour map, an Olympic ash top plate contour map and the like.
In the method for exploring and evaluating the North China coal field collapse column based on the ground directional drilling technology, in the step (4), the critical water bursting coefficient of a region of the coal seam floor, which is damaged by the structure, is 0.06MPa/m, and the critical water bursting coefficient of a region of the coal seam floor, which is complete in water barrier and has no damage to the broken structure, is 0.10MPa/m;
the calculation formula of the thickness M of the safe water-resisting layer of the coal seam bottom plate is as follows:
in the formula (1): p (P) S -the safety water head value, m, of the water-resistant layer of the bottom plate;
T S -critical water break coefficient, MPa/m; a is that 0 The safety coefficient is 1.2-1.5.
In the method for exploring and evaluating the north China type coal field collapse column based on the ground directional drilling technology, in the step (5), the elevation c of the coal bed bottom plate when the collapse column of the main hole position is not developed is estimated according to the contour line of the coal bed bottom plate near the collapse column M Horizontal projection of each directional branch hole and boundary intersection point C of collapse column i Coal seam floor elevation C at (i=1, 2,3 … …) position Ci (i=1, 2,3 … …), and according to M and C Ci Calculating the final hole depth of the main hole and determining the final hole elevation F of each directional branch hole Ci The method comprises the steps of carrying out a first treatment on the surface of the Description: the elevation of the original non-collapse column developing coal seam bottom plate of each point is obtained by adopting an interpolation method according to a contour map of the coal seam bottom plate;
(1) the calculation formula of the final hole depth of the main hole is as follows:
d M ＝z M -c M +M (3)；
in the formula (3): d, d M -main hole final hole depth, m;
z M -the ground elevation of the hole opening position of the main hole, m;
c M -elevation of the coal seam floor when the main hole position collapse column is not developed, m;
m, the thickness of a safe water-resisting layer of the coal seam bottom plate;
(2) the calculation formula of the elevation of each directional branch Kong Zhongkong is as follows:
in the formula (4): c (C) Ci -horizontal projection of directional branch hole and boundary intersection point C of collapse column i The elevation of the coal seam floor at the (i=1, 2,3 … …) position, m; f (F) Ci -the final pore elevation of the branch pore, m.
The method for exploring and evaluating the North China coal field collapse column based on the ground directional drilling technology comprises the following steps of:
(1) the calculation formula of the vertical displacement (Vertical displacement) of each directional branch hole is as follows:
in formula (5): v (V) i -vertical displacement of the directional branch hole (i=1, 2,3 … …), m;
r is the radius of the directional branch Kong Zaoxie, the value is more than or equal to 200m, namely the dog leg angle is less than or equal to 8.60 degrees/30 m; h i -horizontal displacement of the directional branch hole (i=1, 2,3 … …), m; the larger the deflecting radius is, the smaller the curvature is, namely the smaller the dog leg angle is, and the lower the construction difficulty is; the smaller the deflecting radius is, the larger the curvature is, the higher the requirement on the strength (such as bending strength) of drilling tool materials is, and the greater the construction difficulty is; the deflecting radius can be infinite, namely a straight hole, and the dog leg angle is 0 degree/30 m;
(2) length (Length) L of each directional branch hole i The calculation formula of (2) is as follows:
in formula (6): l (L) i -directional branching hole length (i=1, 2,3 … …), m; r—directional branch Kong Zaoxie radius, m;
(3) sidetrack (sidetrack) elevation S of each directional branch hole i The calculation formula of (2) is as follows:
S i ＝C Ci -M+V i (7)；
in the formula (7): s is S i -sidetrack elevation of directional branch hole (i=1, 2,3……)，m；
C Ci -horizontal projection of directional branch hole and boundary intersection point C of collapse column i The elevation of the coal seam floor at the (i=1, 2,3 … …) position, m; m-thickness of the safe water-proof layer of the coal seam bottom plate.
According to the north China coal field collapse column exploration and evaluation method based on the ground directional drilling technology, in the step (7), the main hole is formed by three-hole structure drilling: firstly, opening, wherein the aperture phi is 311.1mm, the hole depth is 30-50 m, a sleeve with the diameter phi of 244.5X8.94 mm is put in, and the whole section of cement paste is used for fixing the pipe to the orifice; secondly, the hole diameter phi 215.9mm, the hole depth is 10-20 m below the bedrock surface, a sleeve pipe phi 177.8x8.05 mm is put in, and the whole section of cement paste is used for fixing the pipe to the hole opening; three openings, wherein the aperture phi is 152.4mm, and the hole is a bare hole;
after drilling holes into bedrock, coring the holes, and judging the top boundary position I (x) of the collapse column according to the rock core I ，y I ，z I ) The method comprises the steps of carrying out a first treatment on the surface of the After entering the collapse column, observing the core characteristics, the drilling leakage and the change condition of the water level in the hole after drilling is stopped; core features include formation continuity, block shape, scratches, and fillers;
performing 1 hydrogeologic test per 10-50 m of drilling, the hydrogeologic test including one or more of a water pumping test, a water injection test and a pressurized water test to obtain hydrogeologic parameters; the hydrogeologic parameters include single pore water inflow q, permeability coefficient K and permeability rate (permeability rate) q P 。
According to the north China coal field collapse column exploration and evaluation method based on the ground directional drilling technology, in the step (7), when the water pumping test is adopted to measure the water inflow q and the permeability coefficient K of a drilling unit:
single Kong Choushui test was performed according to pumping test Specification- -YS/T5215-2021; according to the data of water inflow Q and water level drop S during water pumping, determining a Q=f (S) curve by a least square method or a graphical method, determining the water inflow of a water pumping hole when the water level drop is 10m according to the Q-S curve, calculating the water inflow when the aperture is 91mm by using a formula (8), and dividing the water inflow by 10m to obtain unit water inflow Q;
in formula (8): q (Q) 91 、R 91 And r 91 Drilling water inflow, influencing radius and drilling radius of 91mm aperture, respectively; q, R and r h -the water inflow, the influence radius and the hole (hole) radius of the borehole to be converted, respectively;
the permeability coefficient K is calculated as:
in the formula (9): k, the osmotic coefficient of the pumping section of the collapse column, m/d; q-water inflow of the borehole to be converted, m 3 /d；r h -the borehole radius of the borehole, m; s, water level is lowered deeply, m.
In the method for exploring and evaluating the North China coal field collapse column based on the ground directional drilling technology, in the water injection test in the step (7), the water permeability is calculated according to the following formula;
in the formula (10): q P -the water permeability of the test section, lu or L/(min·mpa·m);
Q I -water injection test (Injecting water test) steady flow, m 3 /d; h, test head height difference, m; l-the length of the test section, m.
In the method for exploring and evaluating the North China coal field collapse column based on the ground directional drilling technology, in the step (7), the collapse column is subjected to a water pressing test according to the water pressing test procedure YS/T5216-2020, and the water pressing test (Pressing water test) is performed according to three stages of pressures, namely p 1 →p 2 →p 3 →p 4 (＝p 2 )→p 5 (p 1 )，p 1 ＜p 2 ＜p 3 Wherein p is 1 、p 2 、p 3 The three-stage pressure is respectively 0.3MPa, 0.6MPa and 1.0MPa, and the unit water absorption omega and the water permeability q of the test section are measured P ；
In the formulas (11) and (12): omega-unit Water absorption, L/(min.m) 2 )；Q 3 -third stage test stable flow, L/min; l is the length of the test section, m; h 3 -third stage test head, m; q P -the water permeability of the test section, lu or L/(min·mpa·m); p (P) 3 -test pressure in the third stage, MPa;
the permeability coefficient K is calculated according to the following formula:
(a) When the depth of the bottom of the test section from the waterproof layer is greater than the length of the test section:
(b) When the depth of the bottom of the test section from the waterproof layer is smaller than the length of the test section:
(c) The test section is positioned below the ground water level, and when the water permeability is small and the pressure-flow (P-Q) curve is a laminar flow type:
in the formula (13), the formula (14) and the formula (15): k is permeability coefficient, m/d; q (Q) P -pressing flow, m 3 /d; h, test head height difference, m; l is the length of the test section, m; r is (r) h -the borehole radius of the borehole, m, is to be scaled.
North China type coal field collapse column detection based on ground directional drilling technologyIn the step (8), optimizing the sidetrack hole depth and the final hole depth of the directional branch drilling according to the top boundary burial depth and the coal seam burial depth of the main hole actual exposure collapse column; each directional branch hole is a bare hole, and the drilling hole diameter is the same as the three drilling holes of the main hole; constructing each branch hole from bottom to top in sequence according to the opening position of each directional branch hole in the main hole, and comprehensively judging the position I of a Drilling (Drilling in) collapse column on the track of each directional branch hole by adopting comprehensive Drilling logging, rock powder Drilling analysis and weight on Drilling i (x i ，y i ，z i ) (i=1, 2,3 … …) and position O of Drilling (Drilling out) collapse column j (x j ，y j ，z j )(j＝1，2，3……)；
After each directional branch hole enters the collapse column, carrying out hydrogeology test for 1 time every 10-50 m of the entering ruler; the test steps and the evaluation method are the same as those of the main hole; and obtaining hydrogeological parameters of different positions of the collapse column according to the leakage of each directional branch drilling hole, the change condition of the water level in the hole after drilling stop and the hydrogeological test.
The technical scheme of the invention has the following beneficial technical effects:
the invention further confirms the space shape and the hydrogeological characteristics of the collapse column by adopting the modes of drilling and hydrogeological test on the collapse column defined by the ground geophysical prospecting before the design of the coal mine stope of the North China coal field, provides scientific basis for the design of stope and mine prevention and control water, and ensures the safe and efficient production of mines. The north China coal field collapse column exploration and evaluation method based on the ground directional drilling technology has the advantages that the collapse column interpretation accuracy is remarkably improved, and the collapse column with the long axis diameter being more than 25m is particularly aimed.
Drawings
FIG. 1 is a schematic flow chart of a method for exploring and evaluating a North China coal field collapse column based on a ground directional drilling technology in an embodiment of the invention;
FIG. 2 is a schematic plan view of a three-dimensional seismic determined collapse column and its attachment to a seam floor contour, geologic structure, stope preliminary design, survey borehole placement, etc. in an embodiment of the invention;
FIG. 3 is a schematic diagram of the spatial relationship of a trap column, a coal seam, a probe borehole, an Orthoash aquifer, etc. in an embodiment of the invention;
FIG. 4 is a schematic diagram of a trap column exploration borehole structure in an embodiment of the present invention;
figure 5 is a schematic plan view of a single Kong Chengya water incomplete well (hole) pumping test in an embodiment of the invention.
Detailed Description
The north China coal field collapse column exploration and evaluation method based on the ground directional drilling technology in the embodiment specifically comprises the following steps:
(1) Analyzing the extension characteristics of the three-dimensional seismic exploration circle collapse column on the contour diagram of the bottom plate of the shearable layer, and determining the central position point O (x, y, z) of the collapse column on the contour diagram of the bottom plate of the shearable layer, wherein the projection point of the point on the ground is the open position of the collapse column exploration main hole, and the main hole is a vertical hole.
(2) According to the extension range of the three-dimensional seismic exploration ring collapse column on the contour diagram of the coal seam floor, the number (4-8) of directional branch holes of the collapse column exploration holes and the azimuth, horizontal displacement or horizontal length of horizontal projection of the directional branch holes are determined, each directional branch hole is formed by sidetracking a main hole, and the horizontal projection length of each directional branch hole exceeds the projection boundary of the collapse column on the coal seam floor by 10-20 m.
Horizontal displacement of each directional branch hole:
wherein: h i -horizontal displacement of the directional branch hole (i=1, 2,3 … …), m.
l-directional branch hole exceeding
Length, m; taking 10-20;
in the embodiment, for a collapse column with the major axis diameter smaller than 100m, taking the plane projection center point as the open position of a main hole on the ground, laterally drilling 4 directional branch holes at a certain depth section of the main hole, wherein the horizontal projections of the 4 directional branch holes are respectively in the major axis direction and the minor axis direction; for a near-elliptical collapse column with the major axis diameter larger than 100m, taking the plane projection center point as the position of the main hole for exploring the hole opening of the ground, laterally drilling 8 directional branch drilling holes at a certain depth section of the main hole, taking the major axis direction with the horizontal plane projection included angle smaller than 90 degrees with the north direction as the direction of the first branch hole, and designing one directional branch hole every 45 degrees in the clockwise (or anticlockwise) direction; for a collapse column with the long axis diameter larger than 100m and irregular shape, the number of the directional branch holes is designed according to the plane projection shape of the collapse column, so that the projection intervals of the positions of each adjacent directional branch Kong Zhongkong on the horizontal plane are basically equal.
(3) According to hydrogeological data of a coal mine (such as a contour diagram of a coal seam floor, a water filling diagram of a mine, a water level diagram of an Oryza, and a contour diagram of an Oryza roof), the distance between a normally-mined coal seam and an underlying Oryza limestone aquifer near a collapse column and the water head height of the Oryza limestone aquifer are calculated; the estimation method comprises the following steps: (1) the distance between the normal coal seam floor and the underlying Otto limestone aquifer near the collapse column can be calculated by adopting an interpolation method (or extrapolation method) according to the coordinates of each drilling hole near the collapse column and the distance between the coal seam floor and the Otto limestone aquifer at each drilling hole, drawing a contour map of the distance between the coal seam floor and the Otto aquifer on the basis of a contour map of the coal seam floor; (2) the water head height of the Ore aquifer at the center of the collapse column can be obtained by drawing a water level contour diagram of the Ore aquifer on the basis of a contour diagram of a coal seam bottom plate and calculating by adopting an interpolation method (or extrapolation method).
(4) Referring to the rule of "critical water bursting coefficient Ts value in the rule of preventing and controlling water in coal mine" to be determined according to the data of the present region, in general, the section where the base plate is damaged by the structure is calculated according to 0.06MPa/M, the section where the water barrier is complete and has no damage to the structure is calculated according to 0.1MPa/M "and the structural complexity degree near the collapse column, the critical water bursting coefficient Ts value is selected, and the thickness M of the water barrier of the base plate near the collapse column meeting the safe exploitation of the coal seam is calculated:
wherein: m, the thickness of a water-resisting layer of the bottom plate, M;
P S -the safety water head value, m, of the water-resistant layer of the bottom plate;
T S -critical water break coefficient, MPa/m; a is that 0 The safety coefficient is 1.2-1.5.
(5) Calculating the elevation of the original coal bed bottom plate without the collapse column at the center position O point of the collapse column according to the contour line of the coal bed bottom plate near the collapse column, namely the elevation c of the coal bed bottom plate when the collapse column does not develop at the main hole position M Horizontal projection of each directional branch hole and boundary intersection point C of collapse column i Coal seam floor elevation C at (i=1, 2,3 … …) position Ci (i=1, 2,3 … …) and according to M, C Ci Calculating the final hole depth of the main hole and determining the final hole elevation F of each directional branch hole Ci The method comprises the steps of carrying out a first treatment on the surface of the Description: the elevation of the original non-collapse column developing coal seam bottom plate of each point is obtained by adopting an interpolation method according to a contour map of the coal seam bottom plate; .
(1) Main bore final bore depth:
d M ＝z M -c M +M (3)；
in the formula (3): d, d M -main hole final hole depth, m;
z M -the ground elevation of the hole opening position of the main hole, m;
c M -estimating the elevation of the coal seam floor when the main hole position collapse column is not developed, m.
(2) Final hole elevation of each directional branch hole:
F Ci ＝C Ci -M (4)；
in the formula (4): c (C) Ci -intersection point C of branch hole and collapse column boundary i (i＝1，2，3……) floor elevation, m, at the location of the coal seam; f (F) Ci Branch Kong Zhongkong elevation, m.
(6) And selecting the deflecting radius (or dog leg angle) of the deflecting section of the directional branch hole according to the performance of the directional drilling equipment, and designing the track of each directional branch drilling hole.
(1) Vertical displacement (Vertical displacement) of each directional branch hole:
wherein: v (V) i -vertical displacement of the directional branch hole (i=1, 2,3 … …), m; r-the radius of the directional branch Kong Zaoxie, the general value is more than or equal to 200m, namely, the dog leg angle is less than or equal to 8.60 degrees/30 m;
(2) length of each directional branch hole:
wherein: l (L) i -directional branching hole length (i=1, 2,3 … …), m; r-the radius of the directional branch Kong Zaoxie, the value is more than or equal to 200m, namely, the dog leg angle is less than or equal to 8.60 degrees/30 m.
(3) Sidetrack elevation of each directional branch hole:
S i ＝C Ci -M+V i (7)；
wherein: s is S i -designing the sidetrack elevation of the branch hole (i=1, 2,3 … …), m;
C Ci -designing the elevation of the coal seam at the intersection of the projection line of the branch hole on the contour of the coal seam floor and the boundary of the collapse column (i=1, 2,3 … …), m.
(7) Main hole construction
The main hole is a three-hole structure drilling hole: firstly, opening, wherein the aperture phi is 311.1mm, the hole depth is 30-50 m, a sleeve with the diameter phi of 244.5X8.94 mm is put in, and the whole section of cement paste is used for fixing the pipe to the orifice; secondly, the hole diameter phi 215.9mm, the hole depth is 10-20 m below the bedrock surface, a sleeve pipe phi 177.8x8.05 mm is put in, and the whole section of cement paste is used for fixing the pipe to the hole opening; three openings, the aperture phi is 152.4mm, and the hole is a bare hole. The main hole structure can be adjusted according to stratum conditions, drilling machine and drilling tool performances and the like.
After drilling holes into bedrock, coring the holes, and judging the top boundary position I (x) of the collapse column according to the rock core I ，y I ，z I ) The method comprises the steps of carrying out a first treatment on the surface of the After entering the collapse column, carefully observing the core characteristics (such as formation continuity, rock mass shape, scratches, fillers and the like), the change condition of the water level in the hole after the hole is lost and stopped, and the like; carrying out hydrogeology test (such as water pumping test, water injection sample, pressurized water test and the like) for 1 time at 10-50 m of each feeding ruler; and obtaining hydrogeological parameters (such as single-hole water inflow, permeability coefficient, water permeability and the like) according to the drilling leakage, the change of the water level in the hole after stopping drilling and the hydrogeological test, and evaluating the water enrichment and water conductivity of the hydrogeological test section of the collapse column.
(1) Pumping test
When the main Kong Xianla column hydrogeological test section contains water, a water pumping test can be adopted.
Firstly, measuring the stable water level of a collapse column;
secondly, according to the water pumping test Specification (YS/T5215-2021), a single Kong Choushui test is carried out, and the water inflow q and the permeability coefficient K of a drilling unit are measured;
(i) Measurement of Single hole Water gushing quantity q
Evaluating the water enrichment of an aquifer according to the rule of preventing and controlling water in coal mines, wherein the water inflow of a drilling unit is based on the caliber of 91mm and the water level of the pumped water is reduced by 10 m; if the caliber and the reduction are not the same as the above, the water-rich property should be compared after conversion. The conversion method comprises the following steps: firstly, determining a Q=f (S) curve by a least square method or a graphical method according to data of water inflow Q and descending depth S when water is pumped, determining water inflow of a water pumping hole when the descending depth is 10m according to the Q-S curve, calculating water inflow when the aperture is 91mm by using the following formula, and dividing the water inflow by 10m to obtain unit water inflow Q. "
Wherein: q (Q) 91 、R 91 、r 91 Drilling water inflow with a bore diameter of 91mm, influencing the radiusAnd a borehole radius;
Q、R、r h -scaling the water inflow of the borehole, the influence radius and the borehole radius.
(ii) Determination of the permeability coefficient K
Because the pumping test is carried out 1 time per 10-50 m of the entering ruler after the exploration drilling hole enters the collapse column, the pumping test is a single Kong Chengya water incomplete well pumping test, and the permeability coefficient K is preferably calculated according to the following formula:
wherein: k, the osmotic coefficient of the pumping section of the collapse column, m/d;
q-water inflow of pumping hole, m 3 /d；
r h -the borehole radius of the borehole, m;
s, water level is lowered deeply, m.
Finally, the water-rich property and water permeability (or water conductivity) of the hydrogeological test section of the collapse column are evaluated by referring to the water-rich property division standard (table 1) of the aquifer in the annex I of the water regulation and control rule of coal mine and the rock water permeability division table in the water regulation and control handbook of coal mine.
TABLE 1 formation Water-rich partition criteria
Table 2 rock permeability dividing table
(2) Water injection test
The water injection test is a method for approximately measuring the permeability coefficient of a rock stratum when the buried depth of underground water is large or the test layer is a permeable water-free layer. The test method is opposite to the water pumping test, and is characterized in that water is injected into a drill hole, so that the water level in the hole is raised, and the water flow moves from the drill hole to the peripheral aquifer. Forming an inverse funnel curved surface with the drilling hole as the center. And injecting a certain amount of water into the drill hole to enable the water level of the drill hole to be raised to a certain height, and calculating the permeability coefficient K of the rock stratum according to a water injection well formula when the water level and the water injection amount are stable.
Water injection tests are carried out on the drilling exposure collapse columns by referring to the mine curtain grouting Specification (DZ/T0285-2015), the water injection test Specification of water conservancy and hydropower engineering (SL 345-2007), the water injection test Specification (YS/T5214-2021) and the like. Test section water permeability q P Calculated as follows:
wherein: q P -the water permeability of the test section, lu or L/(min·mpa·m);
Q I -stable flow for water injection test, m 3 /d；
H, acting on a water level rising value of a test section, namely a test water head height difference, m;
l-the length of the test section, m.
(3) Pressurized Water test
The pressurized water test is an in-situ penetration test in which a drilled hole is isolated by a plug to a certain length, water is pressurized into the hole, and the permeability of a rock mass is determined according to the relation between the pressure and the flow. The main task is to measure the unit water absorption and water permeability of the rock mass and calculate the permeability coefficient according to the unit water absorption and water permeability, so as to explain the water permeability and the fracture property of the fractured rock mass.
According to the "procedure for Water pressure tests" (YS/T5216-2020), a water pressure test is carried out on a drill hole-exposed collapse column, and the water pressure test is generally carried out according to three stages of pressure, namely p 1 →p 2 →p 3 →p 4 (＝p 2 )→p 5 (p 1 )，p 1 ＜p 2 ＜p 3 Wherein p is 1 、p 2 、p 3 The three-stage pressure is respectively 0.3MPa, 0.6MPa and 1.0MPa, and the unit water absorption omega and the water permeability q of the test section are measured:
wherein: omega-unit Water absorption, L/(min.m) 2 )；
Q 3 -third stage test stable flow, L/min;
l is the length of the test section, m;
H 3 -third stage test head, m;
q P -the water permeability of the test section, lu or L/(min·mpa·m);
P 3 test pressure in the third stage, MPa.
Meanwhile, according to the condition that a collapse column is disclosed in the drilling, the permeability coefficient K is approximately calculated according to the following formula:
(a) When the depth of the bottom of the test section from the waterproof layer is greater than the length of the test section:
(b) When the depth of the bottom of the test section from the waterproof layer is smaller than the length of the test section:
(c) The test section is positioned below the ground water level, and when the water permeability is small and the pressure-flow (P-Q) curve is a laminar flow type:
wherein: k is permeability coefficient, m/d;
Q P -pressing flow, m 3 /d；
H, test head height difference, m;
l is the length of the test section, m;
r h -drilling radius, m.
The water permeability of the test section of the trap column can be evaluated with reference to the following table.
TABLE 3 classification of water permeability of rock and soil mass
(8) Construction of each directional branch hole
According to the actual exposure of the main hole, the conditions of the collapse column (such as the top boundary burial depth of the collapse column, the burial depth of the coal seam and the like) are optimized, and the directional branch drilling parameters (such as the side drilling hole depth, the final hole depth and the like) are optimized; each branch hole is a bare hole, and the drilling hole diameter is the same as the three drilling holes of the main hole. According to the position of each directional branch hole in the hole opening (sidetrack) of the main hole, constructing each branch hole from bottom to top in turn, and adopting drilling comprehensive logging (such as electric logging, sonic logging, radioactive logging and the like), drilling rock powder analysis, drilling weight and the like to comprehensively judge the position I of the drilling collapse column on the track of each branch hole because the branch hole is not easy to core i (x i ，y i ，z i ) (i=1, 2,3 … …), position O of drilled trap column j (x j ，y j ，z j )(j＝1，2，3……)。
After each branch hole enters the collapse column, carrying out hydrogeological test (such as water pumping test, water injection test, water pressing test and the like) for 1 time every 10-50 m of the entering ruler; the test procedure and evaluation method were the same as for the master wells. According to the leakage of each directional branch drilling hole, the change condition of the water level in the hole after drilling stop and the hydrogeologic test, the hydrogeologic parameters (such as single hole water inflow, permeability coefficient, water permeability and the like) of different positions of the collapse column are obtained.
(9) According to the main Kong Jielou collapse column top position I (x I ，y I ，z I ) Drilling into the position I of the collapse column i (x i ，y i ，z i ) With drill site collapse column position O j (x j ，y j ，z j ) Normal coal seam bottom near delineating collapse column for delineating three-dimensional seismic explorationThe actual spatial morphology of the trap column below the plate by M depths to the top boundary of the trap column.
Drawing contour plots of various hydrogeologic parameters (such as single-hole water inflow, permeability coefficient, water permeability and the like) in the trapping column according to the results of the hydrogeologic test of each section of the main hole and the branch hole in the trapping column, and comprehensively evaluating the water enrichment property, the water conductivity and the water burst danger of surrounding coal seam exploitation of the trapping column by referring to tables 1-3; and comparing and analyzing the accuracy and reliability of the three-dimensional seismic exploration.
The long axial length of the collapse column in the embodiment is 172m, and the accuracy of collapse column explanation can be effectively improved by adopting the coal field collapse column exploration and evaluation method based on the ground directional drilling technology.
It is apparent that the above examples are given by way of illustration only and are not limiting of the embodiments. Other variations or modifications of the above teachings will be apparent to those of ordinary skill in the art. It is not necessary here nor is it exhaustive of all embodiments. While the obvious variations or modifications which are extended therefrom remain within the scope of the claims of this patent application.
Claims (10)
1. The North China coal field collapse column exploration and evaluation method based on the ground directional drilling technology is characterized by comprising the following steps of:
(1) Determining the central position point O (x, y, z) of the collapse column on the contour diagram of the bottom plate of the shearable layer by utilizing the extension distribution of the collapse column on the contour diagram of the bottom plate of the shearable layer, and determining the open position of the exploration main hole according to the central position point;
(2) Determining the number of directional branch holes of the collapse column, and designing the horizontal projection azimuth and horizontal displacement of the directional branch holes;
(3) Analyzing and calculating to determine the distance between the bottom plate of the coal bed and the Otto aquifer near the collapse column and the water head height of the Otto aquifer;
(4) Determining a critical water inrush coefficient, and calculating the thickness M of a safe water-resisting layer of a coal seam floor;
(5) Calculating the final hole depth of the main hole of the collapse column exploration, and determining the final hole elevation of the directional branch hole;
(6) Determining the deflecting radius or dog leg angle of the deflecting section of the directional branch hole and the track of each directional branch drilling hole;
(7) Constructing a main hole, drilling and coring the main hole, judging the top boundary position of the collapse column according to the rock core, and performing a hydrogeological test on the collapse column section;
(8) Constructing a directional branch hole, judging the upper interface and the side interface of the collapse column, and carrying out hydrogeological test on the collapse column section;
(9) Determining the actual space form of the collapse column from M depth below the coal bed bottom plate to the top boundary of the collapse column according to the determined top boundary position of the collapse column, the upper boundary and the boundary of the collapse column, and comparing and analyzing with the position of the collapse column defined by the three-dimensional seismic exploration; and analyzing and evaluating the water enrichment and water conductivity of the collapse column and the water inrush danger of mining of surrounding coal beds according to the result of the hydrogeological test.
2. The method for exploring and evaluating the collapse column of the North China coal field based on the ground directional drilling technology, which is characterized in that in the step (1), the open position of the main exploration hole is the projection point of the center position point O (x, y, z) of the collapse column defined by the three-dimensional ground 5-seismic exploration; probing the main hole as a vertical hole;
in the step (2), the number of the directional branch holes and the azimuth and horizontal displacement of the horizontal projection of the directional branch holes are determined according to the extension range of the three-dimensional seismic exploration trap column on the contour diagram of the bottom plate of the shearable layer; the number of the directional branch holes is 4-8; each directional branch hole is formed by sidetrack drilling of a main probing hole; the horizontal projection length of the directional branch hole exceeds the projection boundary of the collapse column on the coal seam floor by 10-20 m;
in the step (3), the distance between a normal bottom plate of a shearable layer and an underlying Otto limestone aquifer near a collapse column and the water head height of the Otto limestone aquifer at the central position of the collapse column are calculated according to coal mine geological data and hydrogeological data; the coal mine geological data and the hydrogeological data comprise a coal seam bottom plate contour map, a drilling histogram, a mine water filling map, an Orthograine layer contour map and an Orthograine top plate contour map.
3. The method for exploring and evaluating the north China coal field collapse column based on the ground directional drilling technology as set forth in claim 2, wherein the calculation formula of the horizontal displacement of each directional branch hole is as follows:
in the formula (1): h i -horizontal displacement of the directional branch hole (i=1, 2,3 … …), m;
l-directional branch hole exceeding
Length, m; taking 10-20;
for a collapse column with the major axis diameter smaller than 100m, drilling 4 directional branch holes at the side of the main hole section, wherein the horizontal projections of the 4 directional branch holes are respectively in the major axis direction and the minor axis direction;
for a near-elliptical collapse column with the major axis diameter larger than 100m, 8 directional branch holes are drilled at the side of the main hole section, the major axis direction with the included angle smaller than 90 degrees between the horizontal plane projection of the collapse column and the north direction is taken as the direction of the first branch hole, and one directional branch hole is designed every 45 degrees in the clockwise or anticlockwise direction;
for a collapse column with a long axis diameter larger than 100m and a irregular shape, the number of the directional branch holes is designed according to the plane projection shape of the collapse column, so that the projection distance of the final hole positions of any two adjacent directional branch holes on the horizontal plane is equal.
4. The method for exploring and evaluating the North China coal field collapse column based on the ground directional drilling technology, which is characterized in that in the step (4), the critical water burst coefficient of a zone where the coal seam bottom plate is damaged by the structure is 0.06MPa/m, and the critical water burst coefficient of a zone where the water barrier of the coal seam bottom plate is complete and no fracture structure is damaged is 0.10MPa/m;
the calculation formula of the thickness M of the safe water-resisting layer of the coal seam bottom plate is as follows:
in the formula (2): p (P) S -the safety water head value, m, of the water-resistant layer of the bottom plate;
T S -critical water break coefficient, MPa/m; a is that 0 The safety coefficient is 1.2-1.5.
5. The method for exploration and evaluation of a sunk column in a North China coal field based on the ground directional drilling technology as set forth in claim 1, wherein in the step (5), the elevation c of the coal bed bottom plate when the sunk column of the main hole position is not developed is estimated according to the contour line of the bottom plate of the shearable layer near the sunk column M Horizontal projection of each directional branch hole and boundary intersection point C of collapse column i Coal seam floor elevation C at (i=1, 2,3 … …) position Ci And according to M and C Ci Calculating the final hole depth of the main hole and determining the final hole elevation F of each directional branch hole Ci ；
(1) The calculation formula of the final hole depth of the main hole is as follows:
d M ＝z M -c M +M (3)；
in the formula (3): d, d M -main hole final hole depth, m;
z M -the ground elevation of the hole opening position of the main hole, m;
c M -elevation of the coal seam floor when the main hole position collapse column is not developed, m;
m, the thickness of a safe water-resisting layer of the coal seam bottom plate;
(2) the calculation formula of the final hole elevation of each directional branch hole is as follows:
F Ci ＝C Ci -M (4)；
in the formula (4): c (C) Ci -horizontal projection of directional branch hole and boundary intersection point C of collapse column i The elevation of the coal seam floor at the (i=1, 2,3 … …) position, m; f (F) Ci -final hole elevation of the directional branch hole, m.
6. The method for exploration and evaluation of a north China coal field collapse column based on the ground directional drilling technology as set forth in claim 1, wherein in the step (6):
(1) vertical displacement V of each directional branch hole i The calculation formula of (2) is as follows:
in formula (5): v (V) i -vertical displacement of the directional branch hole (i=1, 2,3 … …), m; r, the deflecting radius of the directional branch hole is larger than or equal to 200m, namely, the dogleg angle is smaller than or equal to 8.60 degrees/30 m; h i -horizontal displacement of the directional branch hole (i=1, 2,3 … …), m;
(2) length L of each directional branch hole i The calculation formula of (2) is as follows:
in formula (6): l (L) i -directional branching hole length (i=1, 2,3 … …), m; r-the deflecting radius of the directional branch hole, m;
(3) side drilling elevation S of each directional branch hole i The calculation formula of (2) is as follows:
S i ＝C Ci -M+V i (7)；
in the formula (7): s is S i -sidetrack elevation of directional branch hole (i=1, 2,3 … …), m;
C Ci -horizontal projection of directional branch hole and boundary intersection point C of collapse column i The elevation of the coal seam floor at the (i=1, 2,3 … …) position, m; m-thickness of the safe water-proof layer of the coal seam bottom plate.
7. The method for exploration and evaluation of a north China coal field collapse column based on the ground directional drilling technology as set forth in claim 1, wherein in the step (7), the main hole is a three-hole structure drilling: firstly, opening, wherein the aperture phi is 311.1mm, the hole depth is 30-50 m, a sleeve with the diameter phi of 244.5X8.94 mm is put in, and the whole section of cement paste is used for fixing the pipe to the orifice; secondly, the hole diameter phi 215.9mm, the hole depth is 10-20 m below the bedrock surface, a sleeve pipe phi 177.8x8.05 mm is put in, and the whole section of cement paste is used for fixing the pipe to the hole opening; three openings, wherein the aperture phi is 152.4mm, and the hole is a bare hole;
after drilling holes into bedrock, coring the holes, and judging the top boundary position I (x) of the collapse column according to the rock core I ，y I ，z I ) The method comprises the steps of carrying out a first treatment on the surface of the After entering the collapse column, observing the core characteristics, the drilling leakage and the change condition of the water level in the hole after drilling is stopped; core features include formation continuity, block shape, scratches, and fillers;
performing 1 hydrogeologic test per 10-50 m of drilling, the hydrogeologic test including one or more of a water pumping test, a water injection test and a pressurized water test to obtain hydrogeologic parameters; the hydrogeologic parameters comprise single-hole water inflow q, permeability coefficient K and water permeability q P 。
8. The method for exploration and evaluation of the collapse column of the North China coal field based on the ground directional drilling technology, as set forth in claim 7, wherein in the step (7), when the water pumping test is adopted to measure the water inflow q and the permeability coefficient K of a drilling unit:
single Kong Choushui test was performed according to pumping test Specification- -YS/T5215-2021; according to the data of water inflow Q and water level drop S during water pumping, determining a Q=f (S) curve by a least square method or a graphical method, determining the water inflow of a water pumping hole when the water level drop is 10m according to the Q-S curve, calculating the water inflow when the aperture is 91mm by using a formula (8), and dividing the water inflow by 10m to obtain unit water inflow Q;
in formula (8): q (Q) 91 、R 91 And r 91 Drilling water inflow, influencing radius and drilling radius of 91mm aperture, respectively; q, R and r h -the water inflow, the influence radius and the borehole radius of the borehole to be converted, respectively;
the permeability coefficient K is calculated as:
in the formula (9): k, the osmotic coefficient of the pumping section of the collapse column, m/d; q-water inflow of the borehole to be converted, m 3 /d；r h -the borehole radius of the borehole, m; s, water level is lowered deeply, m;
in the water injection test in the step (7), the water permeability is calculated according to the following formula;
in the formula (10): q P -the water permeability of the test section, lu or L/(min·mpa·m);
Q I -stable flow for water injection test, m 3 /d; h, test head height difference, m; l-the length of the test section, m.
9. The method for exploration and evaluation of the trapping column of North China coal field based on the ground directional drilling technique as set forth in claim 7, wherein in the step (7), the trapping column is subjected to a water pressure test according to the water pressure test procedure YS/T5216-2020, the water pressure test is performed in five stages, namely, p 1 →p 2 →p 3 →p 4 (＝p 2 )→p 5 (p 1 )，p 1 ＜p 2 ＜p 3 Wherein p is 1 、p 2 、p 3 The three-stage pressure is respectively 0.3MPa, 0.6MPa and 1.0MPa, and the unit water absorption omega and the water permeability q of the test section are measured P ；
In the formulas (11) and (12): omega-unit Water absorption, L/(min.m) 2 )；Q 3 -third stage test stable flow, L/min; l is the length of the test section, m; h 3 -third stage test head, m; q P -the water permeability of the test section, lu or L/(min·mpa·m); p (P) 3 -test pressure in the third stage, MPa;
the permeability coefficient K is calculated according to the following formula:
(a) When the depth of the bottom of the test section from the waterproof layer is greater than the length of the test section:
(b) When the depth of the bottom of the test section from the waterproof layer is smaller than the length of the test section:
(c) The test section is positioned below the ground water level, and when the water permeability is small and the pressure-flow (P-Q) curve is a laminar flow type:
in the formula (13), the formula (14) and the formula (15): k is permeability coefficient, m/d; q (Q) P -pressing flow, m 3 /d; h, test head height difference, m; l is the length of the test section, m; r is (r) h -the borehole radius of the borehole, m, is to be scaled.
10. The method for exploring and evaluating the north China coal field collapse column based on the ground directional drilling technology, which is characterized in that in the step (8), the side drilling opening depth and the final hole depth of the directional branch drilling are optimized according to the top boundary burial depth and the coal seam burial depth of the collapse column which are actually disclosed by a main hole; each directional branch hole is a bare hole, and the drilling hole diameter is the same as the three drilling holes of the main hole; constructing each branch hole from bottom to top in sequence according to the opening position of each directional branch hole in the main hole, and comprehensively judging the position I of a drilled collapse column on the track of each directional branch hole by adopting comprehensive drilling logging, rock powder drilling analysis and weight on drilling i (x i ，y i ，z i ) (i=1, 2,3 … …) and position O of drilling the trap column j (x j ，y j ，z j )(j＝1，2，3……)；
After each directional branch hole enters the collapse column, carrying out hydrogeology test for 1 time every 10-50 m of the entering ruler; the test steps and the evaluation method are the same as those of the main hole; and obtaining hydrogeological parameters of different positions of the collapse column according to the leakage of each directional branch drilling hole, the change condition of the water level in the hole after drilling stop and the hydrogeological test.
Priority Applications (1)
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| CN117610939A (en) * | 2024-01-18 | 2024-02-27 | 天科院环境科技发展（天津）有限公司 | Port dangerous cargo container yard environment risk assessment method and system |
| CN117610939B (en) * | 2024-01-18 | 2024-05-07 | 天科院环境科技发展（天津）有限公司 | Port dangerous cargo container yard environment risk assessment method and system |
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