JAMES R HENDERSON
Medical Practice in Dallas, TX

4031959, Jun 28, 1977

Jul 7, 1976

5/703216

James H. Henderson - Dallas TX

Permeator Corporation - Houston TX

E21B 4304, E21B 4326, E21B 4327

166307

In the disclosed method, an aqueous solution of alkaline earth metal hydroxides and a salt of an alkaline earth metal is injected down a well bore and into a hydrocarbon reservoir in volume quantities sufficient to fill the pore spaces of said reservoir to some distance from the well bore. The concentration of the alkaline earth metal cations is greater than 10,000 ppm and the pH of the aqueous solution is greater than 10. The solution is forced under pressure out into the subterranean reservoir for a time period which is insufficient to consolidate sand but which is sufficient to permanently alter the properties of indigenous, intergranular clay sized particles and thereby achieve desirable permeability effects in certain fluid sensitive reservoirs. After a sufficient time period has elapsed, the well head pressure is released thereby allowing the solution to flow back into the well bore. Hydrocarbon productivity from water sensitive and low-permeable ("tight") reservoirs is improved by this method of permanently altering intergranular clays to prevent permeability reductions caused by clay migration or clay expansion.