Excavation of the Partial Seam CRIP Underground Coal Gasification Test Site: Fid-Bau Portal

Excavation of the Partial Seam CRIP Underground Coal Gasification Test Site

R. J. Cena / J. A. Britten / C. B. Thorsness

In the fall of 1983, Lawrence Livermore National Laboratory conducted the Partial Seam CRIP (PSC) underground coal gasification (UCG) field experiment at the Washington Irrigation and Development Company mine near Centralia, Washington. The test, in the subbituminous Big Dirty coal seam, lasted 30 days during which time 1400 cubic meters of coal were consumed from two injection/production well combinations. In the spring of 1986, normal mining activity in the vicinity of the PSC test allowed the opportunity to carefully excavate the experiment and examine the post-burn cavities. The mining operation dug out the front and back half of the test area and most of the overburden above the UCG cavities, leaving approximately 23,000 cubic meters of earth containing the main portion of the test area undisturbed. Under direction of the Wyoming Research Institute (WRI), this remaining earth was carefully excavated, in slices perpendicular to the original injection/production line, using small earthmoving equipment to uncover and sample the final burn cavities. Preliminary results of the excavation were presented by WRI at the 12th Underground Coal Conversion Symposium. We present additional results and conclusions based on all of the information obtained. Topics covered include: comparison to material balance and thermal instrumentation data, analysis and composition of samples taken from the cavity and general cavity shape and characteristics in comparison with mechanistic models of cavity growth. 10 refs., 10 figs., 1 tab. (ERA citation 12:044863)