Diedich I. Parameters of coal seams extraction using progressing drilling of degassing wells from the surface

The thesis deals with solving the scientific and practical problem of prediction and selection of degasing parameters using degasing wells that are drilled from the surface and then undermined with longwall face. Interaction of the wells and the longwall face has been investigated and its advance rate impact was studied for the relevant parameters of degasing selection. Mutual sliding of adjacent rock layers is the main reason of cutting the wells. Author detected the most probable locations on the stratigraphic sequence where such cutting may emerge. New method and a special diagram have been developed to forecast the cuts locations and their magnitude. New methods were developed to prevent the well damage during its undermining using coordination of well and longwall face parameters including the rate of the face advance. Results of investigation integrated in the coal industry regulations concerning safe use of degasing systems and have been introduced into practice during coal bed methane deposit extraction.