LIGHT-WEIGHT PLUGGING MORTAR Russian patent published in 2003 - IPC

FIELD: plugging mortars applicable in cementing of casing strings of gas, gas-condensate or oil wells. SUBSTANCE: light-weight plugging mortar including oil-well portland cement, aluminosilicate hollow microspheres and 4-% solution of calcium chloride, additionally contains fluid loss reducer in the form of complex reagent. Light-weight plugging mortar contains the following ratio of components, mas.%: oil-well portland cement, 53.-53.09; aluminosilicate hollow microspheres, 9.34-9.37; complex reagent, 0.06-0.31; 4-% solution of calcium chloride, 37.38-37.48. Technical result of the invention consists in development of light-weight plugging mortar with density of 1.46 g/cu.cm with fluid loss through mud crust of 20-30 cu.cm for 30 min. EFFECT: improved plugging properties of light-weight plugging mortar due to its reduced fluid loss. 1 tbl, 1 ex