LLL in-situ coal gasification project. [27 references]

Conference · Sat Jan 01 04:00:00 EST 1977

OSTI ID:7303644

Hill, R W; Stephens, D R; Thorsness, C B

An approach to in-situ gasification originated at LLL utilizes an array of chemical explosives to enhance the permeability of a reaction zone within a thick bed of coal. Results from the first field test of this concept, the Packed Bed Process, are described. Experiment No. 1 was a simple two-spot fracturing experiment that was carried out at Hoe Creek, Wyoming. It consisted of two explosive charges fired simultaneously at the bottom of a coal seam. Pre and post fracture characterization of the site show that the coal permeability was stimulated from 0.3 darcy preshot to about 2-4 darcies postshot. Examination of cores taken after the blast showed moderate to heavy fracturing in the upper few feet of the coal bed, then a lesser fractured zone in the middle, and a highly pulverized zone at the bottom 5-10 ft of the coal bed. A review of flow behavior has led to the conclusion that permeability is not a simple function of the degree of fracturing. On October 15, 1976 the coal was ignited and gasification proceeded for 11 days. During this time, 116 tons of coal was gasified out of an estimated 1000 tons of coal within the fractured region. Heating quality of the gas averaged 110-150 Btu/scf. Design calculations for a new explosive fracture experiment are in progress. A model emphasizing tensile failure and including crack closure is being used. The experiment, to be done early in FY 1978, will be designed to provide a definitive test of the theory. Plans for a LVW experiment called Hoe Creek No. 2 are described. This will be a two well reverse burn-forward burn experiment. The shaped change coal drilling program is described. Tests of new charge designs will be conducted to determine whether or not the penetration distance can be made large enough to serve as an economical linking method.

• Research Organization: California Univ., Livermore (USA). Lawrence Livermore Lab.
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 7303644
• Report Number(s): UCRL-79668; CONF-770652-6
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010404* -- Coal
Lignite
& Peat-- Gasification
011000 -- Coal
Lignite
& Peat-- Reserves
Geology
& Exploration
CALORIFIC VALUE
CHEMICAL EXPLOSIVES
COAL DEPOSITS
COAL GASIFICATION
COMBUSTION PROPERTIES
COMMINUTION
DESIGN
ENERGY SOURCES
EXPLOSIVE FRACTURING
EXPLOSIVES
FLUIDS
FRACTURING
FUEL GAS
FUELS
GAS FUELS
GASES
GASIFICATION
GEOLOGIC DEPOSITS
IN-SITU GASIFICATION
IN-SITU PROCESSING
LOW BTU GAS
PERMEABILITY
PLANNING
PROCESSING
RESOURCES
THERMOCHEMICAL PROCESSES