METHOD OF PREPARING EMULSION DRILLING MUD BASED ON POLYSACCHARIDE POLYMER Russian patent published in 2005 - IPC

FIELD: oil and gas production.

SUBSTANCE: method comprises preparing two solutions: one hydrocarbon-based and the other water-based, which are then mixed with each other by adding water-based solution to hydrocarbon-based solution. The former is aqueous solution of emulsion-stabilizing alkaline surfactant based on oxyethylated ethanols and/or glycols with polysaccharide polymer and the latter is hydrocarbon solution of polysaccharide polymer. Weight ratio of polysaccharide polymer in hydrocarbon and aqueous solutions is 1:(0.5-3) and initial components are taken in following proportions: 0.25-3.0% polysaccharide polymer, 0.5-1.7% alkaline surfactant, 5.0-20.0% hydrocarbon liquid, and water in balancing percentage. According to invention, hydrocarbon-based solution is supplemented by 0.02-4.0% of organic or inorganic salt as gelation agent; water-based solution is supplemented by 0.4-3.0% of water-soluble potassium or sodium silicate and mineralization regents: potassium, sodium, calcium, and magnesium chlorides or calcium chloride-type formation water; polysaccharide polymer is selected from starch, biopolymer, polyanionic cellulose, carboxymethylcellulose, hydroxymethylcellulose, or their mixture; alkaline surfactant is selected from Synthal BT, polyglycol, triethanolamine, "Oksanol PAV MIT", and their mixture; and hydrocarbon liquid is selected from petroleum products and higher alcohols.

EFFECT: simplified preparation procedure, improved structural and rheological properties of drilling mud, and improved encapsulation and inhibitory properties in relation to drillings at simultaneously preserved high lubrication properties.

7 cl, 2 tbl, 2 ex