Method for selectively plugging water zones

摘要

A method for shutting off or decreasing the production of water from an oil well. An oil well producing excess water is taken off production and a gas is injected into the well, followed by a slug of clean oil containing an emulsifier. The well is then produced as fast as possible. The previously injected gas and water in water-producing zones begin to finger back through the oil slug and forms a viscous emulsion which blocks the further flow of water into the producing well.