Method for increasing recovery of oil

Claim 1

THE METHOD OF INCREASING THE RECOVERY OF OIL FROM A SUBTERRANEAN RESERVOIR HAVING IN COMMUNICATION THEREWITH AT LEAST ONE INJECTION WELL AND AT LEAST ONE PRODUCTION WELL COMPRISING INJECTING INTO SAID RESERVOIR THROUGH SAID INJECTION WELL AND CONTACTING SAID OIL WITH A MIXTURE OF WATER AND A FLUID WHICH IS MISCIBLE WITH SAID OIL AND IS LIQUID AT THE HEREINAFTER SPECIFIED OPERATING PRESSURE; THE VOLUMETRIC RATIO OF WATER TO FLUID IN SAID WATER-FLUID MIXTURE BEING THAT VALUE AT WHICH W/F=(SW-SWR)/SF WHEREIN SWR IS THE RESIDUAL WATER SATURATION ESTABLISHED DURING THE CONDUCT OF THE PROCESS, SW AND SF ARE THE WATER SATURATION AND FLUID SATURATION, RESPECTIVELY, ESTABLISHED IN THE TWO-PHASE, WATER-FLUID REGION OF SAID RESERVOIR AND W/F IS THE RATIO OF WATER TO FLUID IN SAID WATERFLUID MIXTURE; THEREAFTER INJECTING INTO SAID RESERVOIR AND CONTACTING SAID WATER-FLUID MIXTURE WITH A MIXTURE OF WATER AND FREE GAS AT A PRESSURE AT WHICH SAID GAS IS MISICIBLE WITH SAID FLUID AND SAID GAS WILL REMAIN IN A GASEOUS STATE; THE VOLUMETRIC RATIO OF WATER TO GAS IN SAID WATER-GAS MIXTURE BEING THAT VALUE AT WHICH W/G=(SW-SWR)/SG WHEREIN SWR IS THE RESIDUAL WATER SATURATION ESTABLISHED DURING THE CONDUCT OF THE PROCESS, SW AND SG ARE THE WATER SATURATION AND GAS SATURATION, RESPECTIVELY, ESTABLISHED IN THE TWO-PHASE, WATER-GAS REGION OF SAID RESERVOIR AND W/G IS THE RATIO OF WATER TO GAS IN SAID WATERGAS MIXTURE; WHEREBY SAID FLUID MISCIBLY DISPLACES SAID OIL AND SAID GAS MISCIBLY DISPLACES SAID FLUID, SAID WATER AND SAID FLUID FLOW THROUGH SAID TWO-PHASE, WATER-FLUID REGION AT EQUAL VELOCITIES AND SAID WATER AND SAID GAS REGION AT EQUAL VELOCITIES AND SAID WATER AND SAID GAS FLOW THROUGH SAID TWO-PHASE, WATER-GAS REGION AT EQUAL VELOCITIES; AND WITHDRAWING OIL FROM SAID RESERVOIR THROUGH SAID PRODUCING WELL.

Claim 2

THE METHOD OF INCREASING THE RECOVERY OF OIL FROM A SUBTERRANEAN RESERVOIR HAVING IN COMMUNICATION THEREWITH AT LEAST ONE INJECTION WELL AND AT LEAST ONE PRODUCTION WELL COMPRISING INJECTING INTO SAID RESERVOIR THROUGH SAID INJECTION WELL AND CONTACTING SAID OIL WITH A MIXTURE OF WATER AND A FLUID WHICH IS MISCIBLE WITH SAID OIL AND IS LIQUID AT THE HEREINAFTER SPECIFIED OPERATING PRESSURE; THE VOLUMETRIC RATIO OF WATER TO FLUID IN SAID WATER-FLUID MIXTURE BEING THAT VALUE AT WHICH W/F=(SW-SWR)/SF WHEREIN SWR IS THE RESIDUAL WATER SATURATION ESTABLISHED DURING THE CONDUCT OF THE PROCESS, SW AND SF ARE THE WATER SATURATION AND FLUID SATURATION, RESPECTIVELY, ESTABLISHED IN THE TWO-PHASE, WATER-FLUID REGION OF SAID RESERVOIR AND W/F IS THE RATIO OF WATER TO FLUID IN SAID WATERFLUID MIXTURE; THEREAFTER INJECTING INTO SAID RESERVOIR AND CONTACTING SAID WATER-FLUID MIXTURE WITH A MIXTURE OF WATER AND FREE GAS AT A PRESSURE AT WHICH SAID GAS IS MISICIBLE WITH SAID FLUID AND SAID GAS WILL REMAIN IN A GASEOUS STATE; THE VOLUMETRIC RATIO OF WATER TO GAS IN SAID WATER-GAS MIXTURE BEING THAT VALUE AT WHICH W/G=(SW-SWR)/SG WHEREIN SWR IS THE RESIDUAL WATER SATURATION ESTABLISHED DURING THE CONDUCT OF THE PROCESS, SW AND SG ARE THE WATER SATURATION AND GAS SATURATION, RESPECTIVELY, ESTABLISHED IN THE TWO-PHASE, WATER-GAS REGION OF SAID RESERVOIR AND W/G IS THE RATIO OF WATER TO GAS IN SAID WATERGAS MIXTURE; WHEREBY SAID FLUID MISCIBLY DISPLACES SAID OIL AND SAID GAS MISCIBLY DISPLACES SAID FLUID, SAID WATER AND SAID FLUID FLOW THROUGH SAID TWO-PHASE, WATER-FLUID REGION AT EQUAL VELOCITIES AND SAID WATER AND SAID GAS REGION AT EQUAL VELOCITIES AND SAID WATER AND SAID GAS FLOW THROUGH SAID TWO-PHASE, WATER-GAS REGION AT EQUAL VELOCITIES; AND WITHDRAWING OIL FROM SAID RESERVOIR THROUGH SAID PRODUCING WELL.