摘要 |
The present invention relates to a method of cementing a casing of an oil or gas pipeline to a surrounding well wall, where an hydraulic cement slurry is formed and the slurry is deployed in the annulus between the pipeline casing and the surrounding well wall. The cement slurry is formed by mixing together an hydraulic cement, 12 to 24% of silica based on the weight of cement, and water; wherein the silica comprises 1/3 to 2/3 microfine silica and 2/3 to 1/3 silica flour. The invention further relates to a cement slurry for use in the method. |