Temporary gas seal for gas level drift of an in situ oil shale retort

摘要

A temporary gas seal is provided in a gas level drift of an in situ oil shale retort system which includes a production region having a panel of retorts producing gaseous and liquid products and an adjacent retort preparation region where a panel of in situ retorts is being prepared for production. A portion of the gas level drift is connected to the active retorts for withdrawing off gas while adjacent portions of the gas level drift are being developed. Portions of the gas level connected to the active retorts are temporarily sealed by a gas isolation barrier to isolate workers from toxic off gas. The gas isolation barrier can be a bulkhead with one or more openings each sealed by a remotely removable seal, such as a flexible membrane, or a plate that can be remotely removed or opened to unseal such a bulkhead opening. The procedure of temporarily sealing and thereafter opening newly developed portions of the gas level drift system can be repeated to provide stepwise development of the gas level drift system while retorting is carried out in adjacent production regions of the retort system.