APPLICATION OF A SPECIALIZED SLURRY USED FOR CEMENTING TUBULARS IN WELLS PRODUCING SYNTHESIS GAS BY UNDERGROUND COAL GASIFICATION

摘要

Synthesis gas is more effectively produced from the underground gasification of coal from a coal seam when the casing lining is cemented with a cementitious slurry containing a cementitious material, graphite and an aluminum silicate, such as metakaolin. The cementitious slurry of the cement mix sets as a cement sheath at bottomhole static temperatures less than or equal to 65° C. The set cement may withstand extreme dry heat temperatures which are greater than or equal to 800° C.