HYDROPHOBIC EMULSION Russian patent published in 2006 - IPC E21B43/00 

FIELD: oil and gas production.

SUBSTANCE: invention, in particular, relates to emulsion-based process fluids used in well killing and well flushing operations, formation hole bottom treatment, water inflow limitation and shutoff, hydraulic rupture of strata, hydrochloric acid treatments, and other operations carried out when constructing and running oil and gas wells. Object of invention was to create universal multipurpose composition of hydrophobic emulsion based on accessible, economically effective, and feasible components while preserving stability of resulting emulsion owing to properly performing needed operations and saving scarce and expensive oil-soluble surfactants-emulsifiers and stabilizers. Simplified technology of preparing hydrophobic emulsions because of using feasible powdered component will allow one to substantially increase amounts of used high-efficiency multipurpose process fluids based on universal hydrophobic emulsion in oil and gas production. Hydrophobic emulsion according to invention contains 44.5-82.75% crude oil, 0.25-0.5% water-soluble oxidant, namely potassium peroxydisulfate, and 17.00-55.00% mineralized water containing ferric ions in amount from 35 mg/L and more up to saturation.

EFFECT: improved performance characteristics of emulsion and extended its application area.

3 tbl