WELL KILLING FLUID Russian patent published in 2003 - IPC

FIELD: oil gas production, particularly, fluids for perforation and killing of wells. SUBSTANCE: killing fluid includes dispersion medium - solution of magnesium chloride diluted with water from formation to be treated, dispersed phase, reagents- filtration control agents in form of thickeners and surfactants. Magnesium chloride solution contains above 93% of MgCl₂. Chalk is used as dispersed phase. Thickener is used in form of polyacrylamide PRAESTOL 2530-2640. Surfactant is used in form of surfactant of complex action SNPH PKD-0515. Well killing fluid has the following amounts of components, wt.%: said magnesium chloride 8-30; chalk 0-10; said polyacrylamide 0.01-0.2; surfactant of complex action SNPH PKD-0515 0.04-3.0; the balance, said water. Well killing fluid may contain bishofite instead of said magnesium chloride. EFFECT: preserved reservoir properties of producing formations during their secondary tapping in performance of well overhauls and production maintenance and other geological and technical measures, increased efficiency of well completion. 2 cl, 1 tbl, 1 ex