LIGHT WEIGHT PHOSPHATE CEMENTS

摘要

A sealant having a specific gravity in the range of from about 0.7 to about 1.6 for heavy oil and/or coal bed methane fields is disclosed. The sealant h as a binder including an oxide or hydroxide of Al or of Fe and a phosphoric aci d solution. The binder may have MgO or an oxide of Fe and/or an acid phosphate . The binder is present from about 20 to about 50% by weight of the sealant wi th a lightweight additive present in the range of from about 1 to about 10% by weight of said sealant, a filler, and water sufficient to provide chemically bound water present in the range of from about 9 to about 36% by weight of t he sealant when set. A porous ceramic is also disclosed.