Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Laboratory characterization of the spalling properties of the rock cores from the UCG (Underground Coal Gasification) test site near Porto Alegre in Brazil

Technical Report ·
OSTI ID:5596483
One of the principal problems encountered in most of the Underground Coal Gasification (UCG) field tests conducted thus far has been excessive water influx. Spalling-enhanced-drying of coal and overburdens rock has been identified as the principal mechanism of water influx observed in the Hanna UCG field tests in Wyoming Spalling is defined as the chipping, fracturing and breaking off of small rock fragments from the cavity roof due to the combined action of mechanical loading and thermally induced stresses. Spalling is also responsibble for vertical cavity growth and a portion of the heat losses during UCG. A laboratory core characterization method has been developed to determine the spalling properties of overburden rock which are essential to make influx and cavity geometry predictions for a prospective field test. In this study, the spalling properties of the representative rock cores from the UCG test site near Porto Alegre in Brazil have been determined using the laboratory core characterization test which utilizes the temperature-gradient-induced spalling hypothesis.
Research Organization:
Colorado Univ., Boulder (USA). Dept. of Chemical Engineering; Lawrence Livermore National Lab., CA (USA)
DOE Contract Number:
W-7405-ENG-48
OSTI ID:
5596483
Report Number(s):
UCID-21339; ON: DE88006720
Country of Publication:
United States
Language:
English