FOAM-EMULSION COMPOSITION FOR WELL KILLING Russian patent published in 2003 - IPC

FIELD: oil and gas producing industry, particularly, foaming compositions; applicable in well killing for performance of repair operations under conditions of abnormally low formation pressures. SUBSTANCE: foam-emulsion composition includes aqueous solution of calcium chloride with density of (180-1200 kg/cu.m, aqueous solution of condensed spent sulfite-alcohol liquor of 25% concentration, hydrocarbon fluid and filler of plant origin in form of grass flour. The composition includes the following amounts of components, wt. p. p. : calcium chloride solution 100; said solution of sulfide- alcohol liquor 26-28; hydrocarbon fluid 21-23; grass flour 4-11. Grass flour is used in form of ground plant wastes of grain and leguminous, or oil-producing, or spinning crops, or mixtures of annual grasses and perennial plants. Technical result consists in higher foam expansion ratio, reduced filtration properties and deblocking pressure, increased recovery of oil formation permeability coefficient. EFFECT: improved physico-chemical parameters of foam-emulsion composition. 2 cl, 2 dwg, 2 tbl, 3 ex