TREATMENT OF OIL AND OIL-CONTAINING FORMULATIONS

摘要

There is disclosed a method of separating a mixture (e.g. dispersion) of oil and water into oil- rich and water-rich phases, the method comprising the steps: (i) selecting a mixture which comprises oil recovered from a subterranean formation and a treatment formulation, wherein said treatment formulation was added to the oil in order to facilitate its recovery and/or mobility, wherein said treatment formulation has an Interfacial Tension (IFT), measured against a sample of said oil in the range 2 to 20 mN/m; (ii) directing said mixture to a separation means; and (iii) in the absence of a chemical demulsifier, heating the mixture until separation is effected at least partially under gravity. Preferably the IFT is in the range 9 to 12mN/m. The mixture of oil and water may be formed by treating oil in a subterranean formation.