method of cementing a lining of an oil or gas pipe in a surrounding well wall, and hydraulic cement slurry for use in cementing gas or oil wells

摘要

method of cementing a lining of an oil or gas pipe in a surrounding well wall, and hydraulic cement slurry for use in cementing gas or oil wells. The present invention relates to a method for cementing an oil or gas pipe liner in a surrounding well wall, where a hydraulic cement slurry is formed and the slurry is prepared in the circular region between the casing liner. pipe and the surrounding well wall. the cement slurry is formed by mixing together a hydraulic cement, from 12 to 24% silica based on the weight of the cement, and water; wherein the silica comprises from 1/3 to 2/3 of microfine silica and from 2/3 to 1/3 of silica bran. The invention further relates to a cement slurry for use in the method.