Patent ID: 7871526

Claim:
A method of separating a hydrocarbon multiphase fluid mixture, the hydrocarbon fluid mixture (E) comprising an oil phase, a water phase and a gas phase, the method comprising: an application step in which the hydrocarbon fluid mixture (E) is applied to a separator that separates by gravity the hydrocarbon fluid mixture (E) into a liquid layer and a gas layer, the liquid layer being constituted by a water-enriched layer and an oil-enriched layer, the liquid layer being separated from the gas layer by a gas/liquid interface (GLI) having a liquid level (LL) in the separator, wherein the method further comprises: a) an extraction step in which the oil-enriched liquid (O) is extracted from the oil-enriched layer at an oil flow rate (Qo), and in which the water-enriched liquid (W) is extracted from the water-enriched layer at a water flow rate (Qw), b) a liquid-level measurement step in which the liquid level (LL) is measured, c) a level-based adjustment step in which one of the flow rates selected from the group consisting of the oil flow rate (Qo) and the water flow rate (Qw) is adjusted so that the liquid level is maintained at a pre-set liquid level value (LLSP), d) a parameter measurement step in which a parameter representative of an impurity ratio present in one of the extracted liquids selected from the group consisting of oil-enriched liquid (O) and water-enriched liquid (W) is measured, and e) a parameter-based adjustment step in which the flow rate not selected in step c) is adjusted so that the parameter representative of an impurity ratio is maintained at a pre-set parameter value.