Methods of reducing the water permeability of subterranean formations

摘要

Improved methods of treating water and hydrocarbons producing subterranean formations to reduce the water permeabilities of the formations without substantially reducing the hydrocarbons permeabilities thereof are provided. The methods basically comprise introducing into the formation a chemical which does not resist water flow and attaches to adsorption sites on surfaces within the porosity of the formation but slowly washes off the sites as another fluid flows through the treated formation. Thereafter, a water flow resisting polymer is introduced into the formation so that it flows deeply into the porosity of the formation before the previously introduced chemical washes off and attaches to the adsorption sites as the chemical washes off.