Geotechnical Studies Related to in-Situ Lignite-Gasification Trials. Semiannual Technical Report, October 1, 1981-March 31, 1982

摘要

The Petroleum Engineering Department at Texas A and M University (TAMU) has conducted field tests on in situ gasification of lignite first at the Easterwood site near the main campus during 1978 and more recently at the Rockdale site adjacent to the Sandow Mine near the town of Rockdale in Milam County, Texas. The present project is related to the gasification trials at the Rockdale site. The objective of the current study is to investigate those geothechnical factors that may influence the performance of the in situ gasification process. These factors include: (1) preexisting fracture patterns in the lignite and their influence on permeability, (2) strength and deformability of the obverburden materials and how these properties are changed by the gasification process and their relationship to subsidence, and (3) the size, shape and orientation of cavities produced by the process and their relationship to local fracture patterns and geologic structure. The current study is necessarily site specific and related to the Rockdale site. Ultimately, the goal is to develop models that would be adaptable to any site with a minimum amount of site-specific investigation.