LIGHT-WEIGHT GASPROOF PLUGGING MATERIAL FOR CEMENTING OVER-PRODUCING INTERVALS (VERSIONS) Russian patent published in 2013 - IPC C09K8/473 

FIELD: chemistry.

SUBSTANCE: invention relates to construction of oil and gas wells, particularly light-weight plugging materials used to cement over-producing intervals of gas, gas condensate or oil wells, primarily with a high gas-oil ratio, higher than 100 m³/t. The plugging material according to one version contains, pts.wt: oil-well portland cement PTST 1G-CC-1 80.0-87.0, hollow aluminosilicate microspheres 10.0-15.0, a stabilising additive - re-dispersible vinyl acetate and acrylate copolymer 3.0-5.0, fluid loss reducing agent - oxyethyl cellulose 0.2-0.3, plasticiser - polyester carboxylates or a substance whose active component is sulphonated melamine formaldehyde 0.1-0.2, antifoaming agent - modified organosilicon reagent POLYCEM DF 0.2-0.3, setting accelerator - calcium chloride 2.0-3.0, water - the balance, wherein the total weight content of the dry mixture of portland cement, hollow aluminosilicate microspheres and the stabilising additive is equal to 100 pts.wt; and according to the second version, the light-weight gasproof plugging material contains, pts.wt: oil-well portland cement PTST 1G-CC-1 76.0-86.0, hollow aluminosilicate microspheres 10-16, a stabilising additive - redispersible vinyl acetate and acrylate copolymer 3.0-6.0 and a reagent Conmix H₂O_stop, the active component of which is sodium silicate 1.0-2.0, fluid loss reducing agent - oxyethyl cellulose 0.1-0.2, plasticiser - a substance whose active component is sulphonated melamine formaldehyde 0.1-0.2, antifoaming agent - modified organosilicon reagent POLYCEM DF 0.2-0.3, setting accelerator - ethyl silicate condensate 0.5-2.0, water 57-60, wherein the total weight content of the dry mixture of portland cement, hollow aluminosilicate microspheres, re-dispersible vinyl acetate and acrylate copolymer and the reagent Conmix H₂O_stop is equal to 100 pts.wt.

EFFECT: two versions of a light-weight plugging material with improved gasproofing properties while also providing the optimum required properties for quality cementing of over-producing intervals in low and normal temperature conditions, specifically: low filtrate volume with low filtration rate and controlled time of formation of static shear stress.

2 cl, 2 tbl