Pressure pulsing perpendicular permeability process for winning stabilized primary volatiles from oil shale in situ

Claim 1

AN IN SITU PROCESS FOR WINNING OIL SHALE FROM AN OIL SHALE FORMATION, THE FORMATION INCLUDING A PRODUCTION BORE HOLE AND AN INJECTION BORE HOLE DRILLED THEREIN, AS WELL AS A PATH OF LATERAL FLUID COMMUNICATION THROUGH THE OTHERWISE IMPERVIOUS OIL SHALE BETWEEN THE PRODUCTION AND INJECTION BORE HOLES, THE PROCESS COMPRISING; (A) PREHEATING THE OIL SHALE ADJACENT THE PATH OF LATERAL FLUID COMMUNICATION WITH HOT WATER TO A TEMPERATURE JUST BELOW THAT AT WHICH PYROLYSIS OF THE OIL SHALE BEGINS, (B) INTRODUCING SUPERHEATED STEAM UNDER PRESSURE INTO THE PATH OF LATERAL FLUID COMMUNICATION THROUGH THE INJECTION BORE HOLE, (C) CYLICALLY VARYING THE SUPERHEATED STEAM PRESSURE BETWEEN THE LIMITS OF ROCK PRESSURE AND A LOWER PRESSURE SUFFICIENT TO PREVENT UNDUE STEAM CONDENSTATION, (D) REMOVING STEAM AND OIL SHALE ENTRAINED VAPOR FROM THE PRODUCTION WELL, AND (E) TREATING THE REMOVED STEAM AND OIL ENTRAINED VAPOR AFTER FIRST REDUCING THE PATIAL PRESSURE OF STEAM BY CONTACT CATALYSIS IN THE PRESENCE OF HYDROGEN.