A local heat preservation and freezing method during the construction of deep vertical shaft freezing method in coal mine

Abstract

The invention relates to a local heat preservation and freezing method during the construction of deep vertical shaft freezing method in coal mine, which comprises the following steps: firstly, the depths of the freezing holes in the inner ring and the freezing holes in the middle ring are determined as L1 and L2 respectively, and then the lengths of L1 and L2 are corresponding to the On the frozen pipes that enter the freezing holes of the outer ring, clean the surface of the frozen pipes that are planned to be L1 and L2 of the outer ring freezing holes. Then use special equipment to smear a certain thickness of thermal insulation coating A layered along the pipe body for the freezing tube of the L1 section of the freezing hole in the outer ring, and apply a certain thickness of thermal insulation coating B layered along the tube body for the freezing tube of the L2 section of the freezing hole of the outer ring. After ensuring the quality of the coating, wrap it with PE film. Finally, the freezing pipes are lowered in sequence according to the construction sequence. During the lowering process, strict attention must be paid to the L1 and L2 sections of the outer ring freezing holes must be frozen pipes treated with thermal insulation coatings and the sequence should be paid attention to. The invention has the advantages of simple process, low cost and can effectively ensure the effect of partial heat preservation and freezing during the construction of the coal mine deep vertical shaft freezing method.

Description

technical field [0001] The invention relates to a local heat preservation and freezing method, in particular to a local heat preservation and freezing method during the construction of a coal mine deep vertical shaft freezing method. Background technique [0002] At this stage, with the exhaustion of shallow coal resources, deep mining is imperative. However, as the mining depth increases, the geological conditions of high water pressure make it difficult to overcome layers of difficulties when building new mines. To solve the above-mentioned problems, the freezing method is commonly used. As the buried depth of new wells increases, the freezing depth also increases. For example, the buried depths of auxiliary shafts and wind shafts in Hetaoyu Coal Mine, Gansu Province are 1005m and 975m respectively (the groundwater pressure is calculated according to P=ρgh, ρ is the density of water, g is the acceleration of gravity, and h is the buried depth of the wellbore, then the gro...

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Problems solved by technology

However, when the external casing is made of polyethylene pipe, it is easy to collide with the hole wall and be damaged during the lowering of the freezing pipe; although the above-mentioned collision damage will not occur if the steel pipe is used, the cost will be greatly increased

Since the freezing time of the formation during the drilling process of the freezing method is usually about one year, if local insulation and freezing are not carried out, it will not be easy to excavate the subsequent wellbore, and secondly, the cost of freezing will increase by 20% to 30%, and it will cost several million more Yuan Renminbi

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