Summary Report on Large-Block Experiments in Underground Coal Gasification, Tono Basin, Washington. Volume 1. Experimental Description and Data Analysis

摘要

The large-block experiments were designed as a series of medium-scale tests of in-situ coal gasification including excavation, so that the cavities could be examined in detail. To keep the cost of postburn excavation at an affordable level, the experiments were located at an exposed coal face. Each of the experiments was constructed by drilling an injection channel into the coal face parallel to the dip for about 30 m (100 ft) and intersecting that hole with a vertical production well from above. The experiments included gasification burns with 1/1 and 3/1 steam/oxygen injection at two different flow-rate schedules, an air-injection burn, and a test of the controlled retracting injection point (CRIP) system. Results indicate that the in-situ coal gasification process at this location is insensitive to changes in steam/oxygen ratio or flow rate over the ranges used. The burn cavities were all mostly filled with rubble and thermally altered coal. (ERA citation 08:008981)