FIELD: chemistry.
SUBSTANCE: invention relates to a cement composition, a method of cementing in an annulus between a well casing and a borehole and a dry cement composition. The cement composition contains: water, a hydraulic cement - portland cement and a weighting system including metal silicon alloys or mixtures thereof, with quartz sand, where the content of the quartz sand is 10-35% of the weight of the cement, wherein the weighting system has density of at least 5.0 g/cm3. The method of cementing in an annulus between a well casing and a borehole involves placing said cement composition in said annulus. The invention is developed in subclaims.
EFFECT: obtaining a composition having high density, while retaining fluid properties such as pumpability, gas-tight sealing, low tendency to segregate and reduced high-temperature cement strength retrogression.
15 cl, 4 tbl, 2 dwg
