Method for deeper penetrating acidizing of siliceous formations

摘要

A method for acidizing siliceous subterranean formations wherein the acidizing composition penetrates the formation to a greater extent before spending comprising injecting into the formation first an organosilane or an ester of an organosilane, preferably in a hydrocarbon carrier liquid, and thereafter an aqueous acidizing composition containing (1) a non-oxidizing mineral acid, acid precursor, low molecular weight organic acid or halogenated derivative thereof, and (2) a fluorine-containing acid or salt.