Method for preventing vertical shaft wellhole from being damaged

Abstract

The invention relates to a method for preventing a vertical shaft wellhole from being damaged by adopting a ground water injection water level stabilization method, comprising the following concrete steps: 1) analyzing the alluvium structure and water regimen, and selecting a loose aquifer of which the water level continuous descends within over three years from the alluvium as a water injection position; 2) constructing a water injection hole around the wellhole with the shape consistent with that of a long-term hydrological observation well; 3) injecting water into the water injection position by tap water or a water pump through a water injection hole; and 4) monitoring the water injection effect in the water injection process, wherein the monitoring contents comprise aquifer water level monitoring and well wall variation monitoring, and the water injection rate is adjusted based on the monitored water injection effect. The method can ensure the water levels of the wellhole and theaquifer nearby to be increased and relatively steady, reduce compression deformation and additional pressure strain on the well wall caused by loosened soil layers around the wellhole due to drop of the water level, thus preventing the well wall from being damaged. Researching from the perspective of hydrology-geological conditions of mines, in the invention, a method for fundamentally solving the problem of preventing the wellhole from being damaged is searched out based on the well wall fracture mechanism, and has obvious prevention effect, is convenient to construction, and is safe and economic.

Description

technical field [0001] The invention relates to the fields of mining engineering and mine hydrogeology, in particular to a method for preventing shaft shaft damage in coal mine shafts by using mine hydrogeological technical means. Background technique [0002] The Huanghuai area is located in the plains of the Yellow River and the Huaihe River, and there are generally deep (thickness greater than 100m) Cenozoic alluvium. This area is an important coal energy base in my country, distributed in: Huainan, Huaibei, Yongxia, Pingdingshan, Datun, Xuzhou, Zaozhuang, Yanzhou, Juye, Feicheng, Xinwen and other large mining areas. The vertical shaft of the layer has an annual coal output of more than 200 million tons. In 1987, there was a sudden rupture disaster in the vertical shaft shaft, and new shaft wall rupture disasters occurred every year thereafter, and by the end of 2005, there were 93 cases. [0003] In order to prevent well wall damage, the following methods are mainly use...

AI Technical Summary

Problems solved by technology

According to the wellbore damage mechanism, if the water level of the loose aquifer remains stable for a long time, the alluvial layer will not undergo compression deformation, and the wellbore will not be damaged. However, so far there has been no engineering example of using the surface water injection method to stabilize the water level to prevent wellbore damage.

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