Baker Hughes Inc researchers Tianping Huang, James B Crews and Michael H. Johnson created methods for using non-aqueous fluids containing certain nanoparticles to selectively inhibit or shut-off the flow of water in underground formations but not inhibit the flow of oil or gas during hydrocarbon recovery operations. The non-aqueous carrier fluids containing nano-sized particles in high concentration are effective for zone isolation and flow control in water shutoff applications for subterranean formations.
The nanoparticles interact with water and solidify it to inhibit its flow, but do not have the same effect on hydrocarbons and thus selectively assist the production of hydrocarbons while suppressing water. Suitable nanoparticles include alkaline earth metal oxides, alkaline earth metal hydroxides, alkali metal oxides, alkali metal hydroxides, transition metal oxides, transition metal hydroxides, post-transition metal oxides, post-transition metal hydroxides, piezoelectric crystals, and/or pyroelectric crystals which are detailed in U.S. Patent Application 2009028670.
Certain subterranean oil producing wells are formed or completed in formations which contain both oil-producing zones and water-producing zones. Unwanted water production is a major problem in maximizing the hydrocarbon production potential of these wells. Tremendous costs may be incurred from separating and disposing of large amounts of produced water, inhibiting the corrosion of pipe used in drilling and replacing tubular equipment downhole, and surface equipment maintenance. Shutting off unwanted water production is a necessary condition to maintaining a productive field. While there is a wide array of treatments available to solve these problems, they all suffer from a number of difficulties, including, but not necessarily limited to, surface mixing and handling problems, etc.
Traditional water shut-off technology with chemicals uses sodium silicate solutions and crosslinked polymers. The silicate solution is typically not compatible with formation waters, since sodium silicate reacts with calcium chloride instantly to generate gel . Thus there remains a need to find a chemical system that will simplify the pumping schedule and permit deep penetration into the formation to shut off the water channels in an effective manner and keep oil flow channels open.