CEMENTING SLURRY Russian patent published in 2020 - IPC C09K8/467 E21B33/138 C04B28/04 C04B18/04 C04B14/04 C04B24/24 C04B111/20 

FIELD: mining.

SUBSTANCE: invention relates to construction of wells, in particular to cementing slurries for cementing of casing strings, gas condensate and oil wells, complicated by availability of loosely bound, perennial permafrost-susceptible to hydraulic fracturing. Cementing slurry containing cementing Portland cement PCT-1-50, expanding component and 4% aqueous calcium chloride solution is characterized by that it additionally contains poly-N-vinylpyrrolidone "Impiron" plasticiser and microsilica, and the expanding component used is calcium oxide in the following ratio of components, wt%: microsilica 8–12, calcium oxide 5–8, poly-N-vinylpyrrolidone 0.4–0.6, cementing Portland cement (PCT-1-50) – balance, and content of 4 % aqueous solution of calcium chloride in the cementing slurry ensures the ratio of the aqueous mixture to base from 0.5 to 0.55.

EFFECT: improving strength and adhesion properties of the formed cement slurry while ensuring its pumping capacity by introducing a plasticiser reagent and reducing the amount of free water in the composition.

1 cl, 1 tbl