Sealing an underground coal deposit for in situ production

Secondary oil shale recovery technique

Situ retort with high grade fragmented oil shale zone adjacent t

Slurry backfilling of in situ oil shale retort

Stability control in underground workings adjacent an in situ oi

Staggered array of explosives for fragmented oil shale formation

Subsidence control at boundaries of an in situ oil shale retort

Subterranean in situ oil shale retort and method for making and

Surface and subsurface hydrocarbon recovery

System and method for enhancing permeability of a...

System for fuel and products of oil shale retort

System for producing a uniform rubble bed for in situ processes

System for undersea recovery of hydrocarbons