Burn cavity growth during the Hoe Creek No. 3 underground coal gasification experiment

Conference · Wed Jan 14 04:00:00 EST 1981

OSTI ID:6328001

Hill, R W

A detailed history is given of the growth of the burn cavity during the first month of the Hoe Creek No. 3 underground coal gasification experiment near Gillette, Wyoming, in 1979. The changing shape of the cavity with time is inferred from data from three types of instruments installed throughout the experimental zone: (1) thermocouples at various levels in a number of holes, to map temperatures; (2) extensometers at various levels in other holes, to detect motions of the overburden material; and (3) high-frequency electromagnetic (HFEM) scans made between various pairs of holes, to detect cavities and zones of burning coal. Additional data on the final shape of the underground cavity are derived from the results of a core drilling program carried out from the surface after the burn had ended. This study of cavity growth history has contributed significantly to our understanding of how the in situ coal gasification process operates in sites like Hoe Creek. The diagnostic system provided invaluable information on cavity growth and on the interaction between the two coal seams. Some new problems with injection well survival and slag production in oxygen-steam burns were brought out, and the importance of understanding and controlling heat loss mechanisms was amply demonstrated. Although no one system of underground diagnostics can give all of the information needed to fully describe the in situ process, a combination of several diagnostic systems can be used to deduce a self-consistent description.

• Research Organization: Lawrence Livermore National Lab., CA (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6328001
• Report Number(s): UCRL-85173; CONF-810909-1
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010404* -- Coal
Lignite
& Peat-- Gasification
CAVITIES
COAL GASIFICATION
DRILL CORES
ENERGY LOSSES
FIELD TESTS
GASIFICATION
GROUND SUBSIDENCE
GROWTH
HEAT LOSSES
IN-SITU GASIFICATION
IN-SITU PROCESSING
LOSSES
MEASURING INSTRUMENTS
MORPHOLOGICAL CHANGES
PROCESSING
TESTING
THERMOCHEMICAL PROCESSES
THERMOCOUPLES