Fluid, useful to treat well bore drilled in oil-base mud, comprises organic continuous phase e.g. emulsion breaking organosoluble additive, dispersed aqueous phase e.g. solid dissolving agent, emulsifier and weighting agent

摘要

Fluid for treating a well bore drilled in an oil-base mud, in the form of water in oil emulsion, comprises an organic continuous phase comprising at least an emulsion breaking organosoluble additive; a dispersed aqueous phase comprising at least a solid dissolving agent and at least a water soluble additive allowing the controlled destabilization of the fluid for treatment; at least an emulsifier; and at least a weighting agent in the form of soluble salts, where the rate and the nature of the water soluble additive is selected for obtaining a delay destabilization. An independent claim is included for a method for treating of well bore drilled in oil-base mud in a single step for treatment comprising preparing the fluid, injecting the emulsion into the well by controlling the kinetics of destabilization of treatment fluid using of water-soluble additive to ensure the breaking of the water in oil emulsion in situ, and treating the well by breaking down of filtration cake on the wall by using organosoluble additive and by dissolving cake solids by the solid dissolving agents.