A method of grouting in gobs of small coal mines based on directional drilling technology

Abstract

The invention provides a small coal mine goaf grouting method based on a directional drilling technology. The advantages of controllable drilling tracks, high goaf disclosing efficiency, high ground adaptability, small drilling work amount, less solid pipe material consumption, low labor strength and the like of the directional drilling technology are fully used for opening up a creatively new path for geological disaster control in a coal mine goaf. The small coal mine goaf grouting method based on the directional drilling technology comprises the steps that a coal seam is horizontally entered through an obliquely straight segment and a deflecting segment, continuous drilling is carried out when coal pillars are encountered in the horizontal drilling process, when the goaf is encountered,a drill rod is recycled, grouting is carried out, after filling grout solidification reaches an another pore-forming condition, hole sweeping is carried out to a previous forming position along an original drilling track, continuous drilling is carried out in solidified man-made geological body, and grouting filling is carried out when entering the goaf again in the forming process. Therefore, the work amount is greatly reduced and the project cost is reduced on the premise of ensuring the grouting control effect of the small coal mine goaf, the innovativeness is greatly achieved, the application range is wide, and market prospects are better.

Description

technical field [0001] The invention relates to the technical field of geological disaster prevention and control in goafs, in particular to a grouting method for goafs in small coal kilns based on directional drilling technology. Background technique [0002] Small coal kiln goaf generally refers to the narrow goaf area formed after coal mine mining, shallow mining depth (mostly within 100m, the deepest can reach 200m~300m), and the plane extension is within 200m. Mined-out areas with branch roadways, irregular or grid-like distribution, mostly unsupported or temporary simple supports. Since the large-scale mining of coal in the 1980s, coal resources have been exploited crazily, forming a large number of gobs in small coal kilns. With the acceleration of urbanization and modernization in my country, the problem of land use for construction has become increasingly prominent. A large number of infrastructure such as roads, railways, bridges, tunnels, reservoir dams, power pl...

AI Technical Summary

Problems solved by technology

[0005] ①Large project volume and high project cost

Since the range of the goaf 2 of the small coal kiln cannot be accurately determined, in order to ensure the treatment effect, more goaf grouting is realized. During the treatment process, the drilling can only be uniformly arranged in an array in the entire area. The spacing is generally 10-25m, which requires large-scale vertical drilling in an area, resulting in a very large overall project volume and high project cost

[0006] ②The proportion of invalid drilling is relatively large

Therefore, there is a large part of invalid vertical boreholes in drilling engineering caused by grouting treatment3

According to the statistics of previous engineering cases, the proportion of invalid drilling is at least as high as 70%, resulting in a large number of drilling projects becoming invalid projects, and at least 70% of the drilling cost was wasted

[0007] ③High pipe fixing work and material consumption

Due to the large number of drilling holes, pipe fixing work is required for each drilling hole, resulting in a huge consumption of steel pipe materials and greatly increasing the project cost

[0008] ④In some areas with complex surface conditions, such as existing buildings (structures), water bodies, large terrain fluctuations, woodland and other surface obstacle areas, vertical drilling construction has problems such as difficulty in moving and delaying the construction period

At the same time, considering the influence range of the overlying rock movement angle and the width of the safety protection belt, the area of ​​goaf treatment is often far beyond the land acquisition scope of the proposed building (structure), resulting in temporary land acquisition.

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