WELL TREATMENT COMPOSITION WITH CARBON DIOXIDE AND METHOD

摘要

Novel compositions comprising homogeneous mixtures of liquid carbon dioxide and an anhydrous lower alkanol gelled to a viscosity of at least 10 centipoises with a hydroxypropyl methylcellulose having a methoxyl degree of substitution of form 0.2 to 1.0 and a molar substitution of hydroxypropoxyl of at least 1.2. The compositions are employed in a method of treating a subterranean formation penetrated by a wellbore by injecting them under pressure down the wellbore and into the formation to sti,ulate production of natural gas or petroleum. Liquefied petroleum gas is normally added to the carbon dioxide, especially at higher bottom hole temperatures. Propping agents can also be mixed with these compositions prior to their injection.