Breaking oil-in-water emulsions and removal of solid matter from the oil

Claim 1

A PROCESS FOR SEPARATION OF A CRUDE OIL-IN-WATER MIXTURE CONTAINING STRATUM PLUGGING MATERIAL AND WATER-OIL EMULSION, SAID MIXTURE BEING RECOVERED FROM A WATERFLOODING OPERATION FROM AN OUTPUT WELL IN A PERMEABLE OIL STRATUM, AND REINJECTING RECOVERED WATER INTO SAID STRATUM THRU AN INPUT WELL, SAID PROCESS COMPRISING THE STEPS OF: (A) PASSING SAID MIXTURE TO A FIRST GRAVITY SEPARATION ZONE SO AS TO SEPARATE SAME INTO AN UPPER OIL PHASE AND A LOWER WATER PHASE CONTAINING A WATER-OIL EMULSION AND STRATUM PLUGGING MATERIAL; (B) PASSING THE LOWER PHASE CONTAINING SAID WATER-OIL EMULSION AND STRATUM PLUGGING MATERIAL SUSPENDED THEREIN IN ADMIXTURE WITH A RELATIVELY LIGHT HYDROCARBON SOLVENT FOR SAID OIL THRU A MIXING ZONE SO AS TO DISSOLVE SAID OIL IN SAID SOLVENT AND FREE THE DISSOLVED OIL OF PLUGGING MATERIAL; (C) PASSING THE EFFLUENT FROM THE MIXING ZONE OF STEP (B) TO A SECOND GRAVITY SEPARATION ZONE SO AS TO SEPARATE SAID EFFLUENT INTO AN UPPER SOLVENT-OIL PHASE AND A LOWER WATER PHASE SUBSTANTIALLY FREE OF OIL AND SOLVENT AND PLUGGING MATERIAL; (D) PASSING THE WATER PHASE FREE OF PLUGGING MATERIAL OF STEP (C) INTO SAID STRATUM THRU AN INPUT WELL ASSOCIATED WITH SAID OUTPUT WELL THRU SAID STRATUM AS WATERFLOODING WATER TO PRODUCE MORE OIL THEREFROM, THEREBY AVOIDING PLUGGING OF THE STRATUM WITH SAID PLUGGING MATERIAL; (E) HEATING THE ZONE OF STEP (A) SO AS TO DISTILL OFF LIGHT HYDROCARBONS FROM THE OIL THEREIN; (F) CONDENSING THE LIGHT HYDROCARBONS FROM STEP (E); AND (G) PASSING THE CONDENSED HYDROCARBONS FROM STEP (F) TO STEP (B) AS SAID SOLVENT.