Local heat preservation freezing method during coal mine deep vertical shaft freezing method construction

Abstract

The invention relates to a local heat preservation freezing method during coal mine deep vertical shaft freezing method construction. The method comprises the following steps of firstly, determining the depth of an inner ring freezing hole and the depth of a middle ring freezing hole as L1 and L2 respectively, and then enabling the lengths of L1 and L2 to correspond to freezing pipes to be placedin an outer ring freezing hole, and cleaning the surfaces of the freezing pipes which are planned to be arranged as the L1 section and L2 section of the outer ring freezing hole; then adopting specialequipment for coating the freezing pipe of the L1 section of the outer ring freezing hole with a heat insulation coating A with a certain thickness along the pipe body layer by layer, coating the freezing pipe of the L2 section of the outer ring freezing hole with a heat insulation coating B with a certain thickness along the pipe body layer by layer, and adopting a PE film for wrapping after coating quality is guaranteed; and finally, sequentially lowering the freezing pipes according to the construction sequence, strictly paying attention to the L1 sections and L2 sections of the freezing holes in the outer ring in the lowering process to ensure the L1 sections and L2 sections must be the freezing pipes treated by the heat insulation coating and paying attention to the sequence. The method is simple in process, low in cost and capable of effectively ensuring the local heat preservation freezing effect during 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...

AI Technical Summary

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

Images