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Claim 1

IN A METHOD FOR RECOVERY OF OIL FROM A PETROLEUM RESERVOIR CONTAINING BRINE AND OIL BY INTRODUCING INTO THE RESERVOIR THROUGH AN INJECTION WELL A SEQUENCE OF SOLVENTS AND DISPLACING THE SOLVENT THROUGH THE RESERVOIR TOWARD A PRODUCING WELL BY INJECTING WATER INTO THE RESERVOIR, SAID SOLVENTS BEING SUCH THAT A FIRST INJECTED SOLVENT IS MISCIBLE WITH THE RESEVOIR OIL AND SUBSTANTIALLY IMMISCIBLE WITH THE RESERVOIR BRINE, AND A SECOND SOLVENT IS MISCIBLE WITH THE FIRST SOLVENT AND WITH WATER, THE IMPROVEMENT OF INJECTING AS FIRST AND SECOND SOLVENTS LIQUIDS WHICH IN AN AQUEOUS MIXTURE HAVE A BINODAL PEAK LESS THAN 20 PERCENT OF THE SECOND SOLVENT AND WHICH IN AN AQUEOUS MIXTURE HAVE A BINODAL PEAK LESS THAN 55 PERCENT OF THE SECOND SSOLVENT IN THE TOTAL VOLUME OF LIQUIDS WHEN THE MIXTURE CONTAINS A VOLUME OF THE RESEVOIR OIL IN A CONCENTRATION OF ABOUT 35 PERCENT OF THE VOLUME OF THE FIRST INJECTED SOLVENT.