FLUID FOR WELL KILLING Russian patent published in 2002 - IPC

FIELD: well completion, particularly, compositions of solutions used for well killing. SUBSTANCE: fluid for well killing includes surfactant, potassium chloride and water, and additionally contains filtration control agent - hydroxyethylcarboxymethyl starch, condensed spent sulfite-alcohol liquor and chalk with the following ratio of components, wt.%: surfactant, 0.5; potassium chloride, 5.0; hydroxyethylcarboxymethyl starch, 3.0-4.0; condensed spent sulfite-alcohol liquor, 0.5-1.0; chalk, 3.0; water, the balance. Invention provides for fluid for well killing with low filtration in formation conditions amounting to 9-10 cu.cm/30 min at 80 C and 3.5 MPa which allows preservation of initial permeability of producing reservoir possessing some other characteristics required for such fluids. EFFECT: improved characteristics. 2 tbl