EMULSIFING AND STABILISING AGENT FOR INVERT EMULSIONS AND METHOD OF PREPARATION OF INVERT EMULSION DRILL MUD ON ITS BASIS Russian patent published in 2008 - IPC C09K8/35 C09K8/36 

FIELD: oil and gas production industry.

SUBSTANCE: inventions are related to area of oil and gas well drilling. Emulsifing and stabilising agent of invert emulsions contain the following wt %: derivative of tallow oil on the basis of higher fatty acids 6.2-22.0; potassic alkaline agent 4.2-13.5; water 4.5-14.6; dissolvent - non-aromatic claroline - other. Method of preparation of invert emulsion drill mud that includes preparation of pleofil-based mud by introduction of emulsifing and stabilising agent to hydrocarbon reactant at weight ratio (1.5-9):1 correspondingly preparation of water-based mud as mixture of water solution of calcium chloride that ensures minimum concentration of calcium ions in water phase of resulted emulsion 11.6 g/l and water solution of caustic magnesite with concentration 16-120 g/l, their mixture by introducing water-based mud to oleofil-based mud at the following ratio of ingredients, wt %: emulsifier 5-20; hydrocarbon reactant 20-88; calcium chloride 2-3; caustic magnesite 1-3; fresh or salt water - other. Invention is developed in subclaims.

EFFECT: maintenance of pay bed reservoir properties.

9 cl, 4 tbl