Construction technology for unsealing drill hole in coal mine working face

Abstract

The invention discloses a coal mine working face unsealing drill hole construction technology which comprises the following specific construction technological processes that firstly, a hole is explored, specifically, a drill hole is explored, and an optimal drilling tool combination is selected according to the explored drill hole deformation condition; secondly, hole sweeping is conducted, specifically, hole sweeping is conducted through the drilling tool combination selected in the first step, and the hole wall is repaired; 3, punching is conducted, specifically, hole walls are washed with clear water from bottom to top, and rock powder on the hole walls and the hole bottoms is removed; 4, hole sealing is conducted, specifically, cement paste with a certain proportion is prepared, and hole sealing is conducted in a quantitative and segmented mode through a rollback type pumping method; and fifthly, backfilling is conducted, laitance and sewage at the unoccupied section of the hole opening are removed in time after the hole sealing slurry is solidified, and mortar is adopted for backfilling and screeding. According to the construction technology, the optimal drilling tool combination is selected according to the exploration condition, the problem of drilling track deviation of poor-sealing drilling holes in the prior art is solved, and the construction technology is safe, efficient, convenient to operate and capable of effectively reducing the project operation cost.

Description

Technical Field

[0001] The invention relates to the technical field of coal mine drilling, and in particular to a construction process for unsealing a borehole on a coal mine working face. Background Art

[0002] Due to the optimization and adjustment of the mining layout of the mine, the adjusted area is located in the original design of the early mining area, and the exploration level has reached the level of detailed investigation. In accordance with the "Mineral Geological Exploration Specifications for Coal" (DZT0215-2020), "Geological Work Regulations" (2014) and "Coal Mine Water Prevention and Control Regulations" (2018), it is necessary to carry out geological supplementary exploration work in the detailed investigation area to identify the geological structure, coal seam and structure, hydrogeological conditions and engineering geological conditions to meet the needs of safe mining activities. The geological holes previously constructed on the working face need to be resealed. In order to eliminate hidden dangers for the safe production of the mine, eliminate flood hazards, prevent the exposure of boreholes during mine production, and conduct water seepage accidents caused by the upper and lower aquifers, full hole sealing is required. According to the existing traditional unsealing hole operation process, conventional drilling tools are directly used to blindly scan and drill holes. There is no support from key drilling tool combination processes, drilling parameters and other technical data. There are trajectory deviations and it cannot meet the operation needs with high quality and efficiency. Summary of the invention

[0003] In view of the shortcomings of the prior art, the present invention provides a construction process for unsealing drill holes in a coal mine working face. The construction process selects the best drilling tool combination according to the exploration situation, solves the problem of drilling trajectory deviation of poorly sealed drill holes in the prior art, is safe and efficient, easy to operate, and can effectively reduce the project operating costs.

[0004] A construction process for unsealing drilling holes in a coal mine working face, the specific construction process flow is as follows:

[0005] Step 1: Exploring the borehole, exploring the borehole, and selecting the optimal drilling tool assembly according to the detected borehole deformation;

[0006] Step 2: hole cleaning, using the drilling tool assembly selected in step 1 to clean the hole and repair the hole wall;

[0007] Step 3: flush the hole, flush the hole wall from bottom to top with clean water to remove the rock powder on the hole wall and bottom;

[0008] Step 4: Sealing the hole: prepare a certain proportion of cement slurry and seal the hole in quantitative sections using the back-and-forth pumping method;

[0009] Step 5: Backfill. After the sealing slurry solidifies, remove the remaining slurry and sewage in the hole mouth in time, backfill with mortar and smooth it.

[0010] As a preferred embodiment of the above technical solution, in step one, when the drilling state is centerless drilling, the drilling tool assembly uses Φ94mm conical drill bit + Φ68mm drill collar + Φ50mm drill rod + vertical shaft.

[0011] As a preferred embodiment of the above technical solution, in step one, when the drilling state is that the casing is deformed, the drilling tool assembly uses Φ113mm PDC drill bit grinding shoe + Φ68mm drill collar + Φ50mm drill pipe + vertical shaft.

[0012] As a preferred embodiment of the above technical solution, in step one, when the drilling state is normal, a Φ94mm conical drill bit with a guiding performance is selected for drilling; after the hole is swept to the bottom in step two, a Φ113mm guiding performance and a Φ94mm reaming drill bit is selected for reaming.

[0013] As a preferred embodiment of the above technical solution, in step three, when punching, the drill bit is pulled up and down to score the hole to ensure that the hole wall is smooth and round without large protrusions.

[0014] As a preferred embodiment of the above technical solution, in step 4, the cement used to prepare the cement slurry is ordinary Portland cement with a grade of P.O42.5R, and the water-cement ratio of the cement slurry is 1:2.

[0015] As a preferred embodiment of the above technical solution, in step 4, each sealing section does not exceed 30 meters.

[0016] As a preferred embodiment of the above technical solution, in step 4, a 5-10 meter empty section is ensured between the cement slurry surface and the end of the drilling tool each time.

[0017] As a preferred embodiment of the above technical solution, in step five, mortar of model M30 is selected for backfilling.

[0018] As a preferred embodiment of the above technical solution, after step five is completed, stone markers are buried at the openings of all drill holes to record household registration information for easy query.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. Simple operation and easy to apply in actual construction;

[0021] 2. The whole hole section is closed, leaving no hidden dangers and generating great social benefits;

[0022] 3. The drilled holes can be reused for geological exploration and other work, generating greater economic benefits.

[0023] 4. Increase drilling utilization, avoid waste of resources, save costs and protect the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

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

[0027] A construction process for unsealing drilling holes in a coal mine working face, the specific construction process flow is as follows:

[0028] Step 1: Exploring the borehole, exploring the borehole, and selecting the optimal drilling tool assembly according to the detected deformation of the borehole. Specifically, in this embodiment, a Φ94 mm drill bit is preferably used for exploratory drilling;

[0029] Step 2: hole cleaning, using the drilling tool assembly selected in step 1 to clean the hole and repair the hole wall;

[0030] Step 3: flush the hole, flush the hole wall from bottom to top with clean water to remove the rock powder on the hole wall and bottom;

[0031] Step 4: Sealing the hole: prepare a certain proportion of cement slurry and seal the hole in quantitative sections using the back-and-forth pumping method;

[0032] Step 5: Backfill. After the sealing slurry solidifies, remove the remaining slurry and sewage in the hole mouth in time, backfill with mortar and smooth it.

[0033] In this embodiment, in step 1, when the drilling state is centerless drilling, the drilling tool assembly uses Φ94mm conical drill bit+Φ68mm drill collar+Φ50mm drill rod+vertical shaft.

[0034] In this embodiment, in step 1, when the drilling state is that the casing is deformed, the drilling tool assembly uses Φ113mm PDC drill bit grinding shoe + Φ68mm drill collar + Φ50mm drill rod + vertical shaft.

[0035] In this embodiment, in step one, when the drilling state is normal, a Φ94mm conical drill bit with a centering performance is selected for drilling; in step two, after the hole is swept to the bottom, a Φ113mm with a guiding performance and a Φ94mm reaming drill bit is selected for reaming.

[0036] In this embodiment, in step three, when punching, the drill is pulled up and down to score the hole to ensure that the hole wall is smooth and round without large protrusions.

[0037] In this embodiment, in step 4, the cement used to prepare the cement slurry is ordinary Portland cement with a grade of P.O42.5R, and the water-cement ratio of the cement slurry is 1:2.

[0038] In this embodiment, in step 4, each sealing section does not exceed 30 meters.

[0039] In this embodiment, in step 4, a 5-10 meter empty section is ensured between the cement slurry surface and the end of the drilling tool each time.

[0040] In this embodiment, in step five, mortar of model M30 is selected for backfilling.

[0041] In this embodiment, after step five is completed, stone markers are buried at the openings of all drilled holes to record household registration information for easy query.

[0042] Specifically, during the drilling construction process, the following technical requirements need to be met:

[0043] (1) In the hole section without filling material or collapsed hole section, the main method is through-sweeping and flushing, with punching as the main method, supplemented by slow rotation of the drill bit with a smaller diameter. If a cement plug is encountered, a larger diameter core tube is used to sweep and core drill in stages. If an accidental drill bit is encountered in the hole, it shall be handled according to the specific situation.

[0044] ① In the mud filling section, use the drilling method of light pressure, slow rotation and small pump volume to drill. It is necessary to ensure that the mud circulates fully in the hole and replace the mud in the original hole.

[0045] ② In the collapsed hole section, use the drilling method of light pressure, slow rotation and appropriate pump volume to prevent the emergence of large bellies and new holes.

[0046] (2) When drilling in the bedrock section, the drilling pressure should be lower than the pressure when drilling in a normal geological hole, and the pressure should be kept balanced.

[0047] (3) If the penetration rate suddenly increases or drill bit drops during drilling, the drilling tool should be measured in time to determine the starting and ending depths of the borehole sealing section, and the information should be recorded in the original shift report in a timely and detailed manner.

[0048] (4) During the construction process, ensure that the drilling is unsealed according to the original trajectory to prevent the drill bit from falling and getting stuck. The hole inclination is ≤3° within 300m, and the hole inclination increases by ≤1° for every 100m of drilling thereafter.

[0049] (5) Keep good construction records and inspect the sealing materials.

[0050] (6) When encountering residual drilling tools or accident holes in the hole during the unsealing construction process, the accident and the residual drilling tools in the hole must be handled to achieve the designed depth of drilling unsealing and the requirements of grouting and sealing.

[0051] In addition, during the construction process, various construction parameters must be reasonably controlled. Specifically, during the exploration and sweeping of holes, the drill pressure is controlled at 0.5-2.0KN, the drill speed does not exceed 25r / min, and during the sealing process, the pumping volume of cement slurry is controlled at 150-200L / min.

[0052] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A construction process for unsealing drilling in a coal mine working face, characterized in that: The specific construction process is as follows: Step 1: Exploring the borehole, exploring the borehole, and selecting the optimal drilling tool assembly according to the detected borehole deformation; Step 2: hole cleaning, using the drilling tool assembly selected in step 1 to clean the hole and repair the hole wall; Step 3: flush the hole, flush the hole wall from bottom to top with clean water to remove the rock powder on the hole wall and bottom; Step 4: Sealing the hole: prepare a certain proportion of cement slurry and seal the hole in quantitative sections using the back-and-forth pumping method; Step 5: Backfill. After the sealing slurry solidifies, remove the remaining slurry and sewage in the hole mouth in time, backfill with mortar and smooth it.

2. A construction process for unsealing drilling holes in a coal mine working face according to claim 1, characterized in that: In step 1, when the drilling state is centerless drilling, the drilling tool assembly uses Φ94mm conical drill bit + Φ68mm drill collar + Φ50mm drill rod + vertical shaft, and the Φ94mm conical drill bit has a centering performance.

3. The construction process for unsealing drilling holes in a coal mine working face according to claim 1 is characterized in that: In step 1, when the drilling state is that the casing is deformed, the drilling tool assembly uses Φ113mm PDC drill bit grinding shoe + Φ68mm drill collar + Φ50mm drill pipe + vertical shaft.

4. A construction process for unsealing drilling holes in a coal mine working face according to claim 1, characterized in that: In step 1, when the drilling state is normal, a Φ94mm conical drill bit with a centering function is selected for drilling; in step 2, after the hole is swept to the bottom, a Φ113mm with a guiding function and a Φ94mm reaming drill bit is selected for reaming.

5. The construction process for unsealing drilling holes in a coal mine working face according to claim 1, characterized in that: In step three, when punching, pull the drill up and down to score the hole to ensure that the hole wall is smooth and round without large protrusions.

6. The construction process for unsealing drilling holes in a coal mine working face according to claim 1, characterized in that: In step 4, the cement used to make cement slurry is ordinary Portland cement with a grade of P.O42.5R, and the water-cement ratio of the cement slurry is 1:

2.

7. A construction process for unsealing drilling holes in a coal mine working face according to claim 1, characterized in that: In step 4, each sealing section shall not exceed 30 meters.

8. A construction process for unsealing drilling holes in a coal mine working face according to claim 7, characterized in that: In step 4, a 5-10 meter empty section is ensured between the cement slurry surface and the end of the drill bit each time.

9. The construction process for unsealing drilling holes in a coal mine working face according to claim 1, characterized in that: In step five, use M30 mortar for backfilling.

10. The construction process for unsealing drilling holes in a coal mine working face according to claim 1, characterized in that: After step five is completed, all drill holes are marked with stone markers to record household registration information for easy query.

Images