LLL underground coal gasification project: 1978 status. [Hoe Creek No. 2; explosive borehole linking]
Results from the recent LLL underground coal gasification experiment, Hoe Creek No. 2 are presented. It was a two process-well experiment, using both air and oxygen/steam injection: both low and medium-Btu gas were produced. The process wells were spaced 18 m (60 ft) apart and completed within 1.5 m (5 ft) of the bottom of the 7.6 m (25 ft) thick subbituminous coal seam (Felix No. 2), located 38 m (125 ft) below the ground surface. Reverse combustion was used to enhance permeability for Hoe Creek No. 2. The reverse combustion link was completed in 14 days using air injected under high pressure. Following this, gasification was carried out in forward combustion for a period of 58 days. During forward gasification 1635 m/sup 3/ (2436 tons) of coal were consumed producing gas which averaged above 96 kJ/gmol (108 Btu/scf), during air injection. A two-day steam/oxygen burn produced medium Btu gas between 220 to 265 kJ/gmol (250 to 300 Btu/scf) with no operational or safety problems. Good quality gas was produced using oxygen in the same geometry that, with air, produced poor quality gas. This suggests that oxygen injection produced a much hotter burn, consuming the oxygen close to the injection well. It may therefore be possible to obtain better control over product gas quality when using oxygen than when using air. These results are quite encouraging for the commercial prospects of steam/oxygen underground coal gasification. The potential of explosively drilled linkages for underground coal gasification using shaped charges was investigated in a two-part study. The first involves testing of a series of conventional shaped charge designs. The second involves design of a tandem shaped-charge, which incorporates two explosive devices into a single assembly. Calculations indicate that a tandem unit could produce approximately 50% greater penetration than could a single stage device.
- Research Organization:
- California Univ., Livermore (USA). Lawrence Livermore Lab.
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 6725898
- Report Number(s):
- UCRL-81302; CONF-780723-5
- Resource Relation:
- Conference: 4. underground coal conversion symposium, Steamboat Springs, CO, USA, 17 Jul 1978
- Country of Publication:
- United States
- Language:
- English
Similar Records
Hoe Creek No. 2: underground coal gasification experiment with air and oxygen/steam injection periods
Hoe Creek No. 2: underground coal gasification experiment with air and oxygen/steam injection periods
Related Subjects
FUEL GAS
CALORIFIC VALUE
IN-SITU GASIFICATION
REVIEWS
AIR
BOREHOLE LINKING
COAL GASIFICATION
EXPLOSIVE FRACTURING
INTERMEDIATE BTU GAS
LOW BTU GAS
OXYGEN
REVERSE COMBUSTION
STEAM
SUBBITUMINOUS COAL
WELL SPACING
WYOMING
CARBONACEOUS MATERIALS
CHEMICAL REACTIONS
COAL
COMBUSTION
COMBUSTION PROPERTIES
COMMINUTION
CRYOGENIC FLUIDS
DOCUMENT TYPES
ELEMENTS
ENERGY SOURCES
FLUIDS
FOSSIL FUELS
FRACTURING
FUELS
GAS FUELS
GASES
GASIFICATION
IN-SITU PROCESSING
NONMETALS
NORTH AMERICA
OXIDATION
PROCESSING
ROCKY MOUNTAIN REGION
THERMOCHEMICAL PROCESSES
USA
010404* - Coal
Lignite
& Peat- Gasification