Hydrothermal Cement Method of Cementing Well Bores: 3,990,903

A hydrothermal cement composition consisting essentially of (a) a polyvalent metal ion source, (b) water, and (c) a hydratable silica source wherein the silica becomes available for chemical combination with the polyvalent metal salt upon application of heat. A method of cementing a string of pipe in a bore hole including the steps of preparing such a cement composition, pumping the cement composition into the annular space between the string of pipe and the walls of the bore hole, and allowing the cement to set due to the temperature of the bore hole or by passage of time or both.