New High Temperature Cementing Materials for Geothermal Wells: Stability and Properties. Final Report

摘要

Potential high-temperature cements have been formulated and evaluated in terms of their properties for geothermal well cementing. Phase formation and compatibility in two major compositional regions were investigated in the temperature region between 200 and 400 exp 0 C and pressures up to 69 MPa (10,000 psi). These were followed by an evaluation of properties of the cements formed. One area in the system Ca0-Mg0-Si0 sub 2 -H sub 2 0 centered around the xonotlite-chrysotile join while the other area of interest centered around the anorthite composition in the system Ca0-Al sub 2 O sub 3 -SiO sub 2 -H sub 2 O. After numerous exploratory studies, the magnesia-containing mixtures were prepared by mixing a Class J cement with various sources of magnesia such as calcined chrysotile, or magnesium oxide. Calcium oxide and silica fine quartz powder were also added to adjust the compositions. The aluminous system cements were formulated from high-alumina cements which were mixed with various silica sources. (ERA citation 06:004720)