| 摘要 |
<p>A cement composition, especially for cementing subterranean formations, has a density of 1.3 to 1.9 g/cm<3> and comprises : (a) a hydraulic cement; (b) a silicate compound selected from the group consisting of an aqueous alkali metal silicate, an aqueous ammonium silicate and mixtures thereof, said compound being present in amount of from about 0.40 percent to about 3.40 percent by weight of hydraulic cement; (c) sea water present in an amount of from about 42 percent to about 190 percent by weight of hydraulic cement; and (d) a hydroxide compound selected from the group consisting of an alkali metal hydroxide, ammonium hydroxide, calcium hydroxide, and mixtures thereof said hydroxide compound present in an amount of from about 0.2 percent to about 2.0 percent by weight of the sea water; wherein said hydroxide compound is added to the sea water before both of the silicate compound and the hydraulic cement have been added.</p> |
