CEMENT FOR GEOTHERMAL WELL

摘要

PROBLEM TO BE SOLVED: To obtain a cement without deteriorating under an environment of a high temperature and a high pressure for a long period of time and capable of maintaining an excellent desired strength. SOLUTION: This cement for a geothermal well consists of 5-40 wt.% Al2 O3 and 90-50 wt.% cement having a chemical composition of 0.6-2.0 molar ratio of CaO/SiO2 . As the supplying raw material of Al2 O3 , a calcium aluminate, a blast furnace slag, a flyash, a bentonite, an alunite alumina cement, etc. are cited. Also, as the source of CaO/SiO2 , a cement and a clinker are preferably used and among them the cement or a slow-acting clinker having the chemical composition of 0.6-2.0 molar ratio of CaO/SiO2 are preferable.