Preliminary Modeling of Roof Collapse and Calculation of Gas Loss,Water Influx,and Surface Subsidence Associated with the Packed-Bed Scheme of in Situ Coal Gasification.

摘要

Preliminary modeling of roof collapse and calculations of gas loss and water influx for the packed-bed scheme of in situ coal gasification have been carried out. The two models of roof collapse used are thought to represent upper and lower bounds on the degree of fluid flow that is likely to occur. The results show the large effects of overburden fracturing on gas losses and water influx. Values of maximum horizontal and vertical surface displacements have been estimated using currently available empirical results and found to be on the order of 12and 60ft,respectively,for this particular gasification scheme.