Pressure swing recovery system for oil shale deposits

摘要

A process for the in-situ recovery of hydrocarbon, carbon monoxide, and hydrogen values and associated minerals from subsurface oil shale deposits is provided by forming a gas-tight retort chamber and injecting it with various process gases which are pressure cycled over a predetermined period of time. This pressure cycling increases the extraction efficiency by improving the recovery of material contained in blind cracks in the underground formation, and by provising an independent means of controlling the thermal gradients induced in the deposit.