摘要 |
The present invention concerns cementing compositions for an oil well or the like, based on a Portland cement, silica and alumina, wherein the mineralogical composition of the cement matrix is included in the Si-Ca-Al triangle in one of the margarite-haüyne-[epidote/pumpellyite], haüyne-prehnite-[epidote/pumpellyite] and haüyne-prehnite-pectolite composition triangles. More particularly, the cementing compositions of the invention are suitable for cementing wells subjected to high temperatures and to chemical attack by brines, and are more suitable when the brine-or a saline formulation close to that of the brine-is used as the mixing water. |