EXPANDING CEMENT SLURRY FOR WATER INFLUX LIMITATION Russian patent published in 2014 - IPC C09K8/467 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the field of well construction, in particular to cement slurries for water influx limitation. The expanding cement slurry contains the tempering fluid - water and base consisting from plugging Portland cement, hydroxyethyl cellulose, plastifier FOX-8H, silicon antifoamer Sik, calcium chloride and expanding additive - product of joint grinding of gypsum, quicklime, magnesite caustic powder and aluminous cement of the medium chemical composition, by wt %: CaO - 42-47; MgO - 11…13; CaSO₄ - 23-28; mCaO·nAl₂O₃ - 14-17; Fe₂O₃ - 0-0.5; other admixtures - 0-4.5 in the following proportion of the used ingredients, by wt %: oil-well Portland cement - 91.6-94.2; hydroxyethyl cellulose - 0.1-0.25; plastifier FOX-8H - 0.05-0.1; silicon antifoamer Sik - 0.1-0.23; calcium chloride - 2.3-3.1; expanding additive - 3.0-5.0. The water content in the solution provides a water mixture proportion with the base 0.46-0.64.

EFFECT: improvement of sealing of capacity of cement stone obtained from the offered cement slurry due to improved parameters of the basic technological properties of cement slurry stone - high flowability, low filtering, increased expanding capacity, high early strength at a wide range of densities of the cement slurry.

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