LIGHT GROUTING MORTAR Russian patent published in 2000 - IPC

FIELD: oil and gas production. SUBSTANCE: invention relates to grouting mortars used when cementing casing string in gas, gas condensate, and oil boreholes complicated by the presence of weakly bound rocks prone to hydraulic rupture. Mortar contains, wt %: grouting Portland cement 38.89-58.07, hollow aluminosilicate microspheres 6.45-17.14, mud powder 0.71-1.78, water - the balance. When slaking grouting mortar with lightening additive (hollow microspheres based on clayey suspension containing mud powder and water), density of grouting mortar is lowered to 1.25 g/cu.cm. EFFECT: increased spreadability of mortar and improved sedimentation stability. 2 tbl