Viscosity-stabilized aqueous solutions
Patent 4247405 Issued on January 27, 1981. Estimated Expiration Date: 
June 30, 1998. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
June 30, 1998. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3116791 3201367 3235523 3370035 3373808 3412793 3663477 3739848 InventorAssigneeApplicationNo. 05/920884 filed on 06/30/1978US Classes:507/247, Sulfur is attached directly or indirectly to carbon by nonionic bonding166/270.1, Injecting a composition including a surfactant or cosurfactant507/129, Organic component contains nitrogen attached directly or indirectly to carbon by nonionic bonding507/135, Organic component contains a sulfur attached directly to carbon by nonionic bonding (e.g., sulfonate, etc.)507/136, Organic component contains ether linkage (e.g., PEG ether, etc.)507/259, The sulfur is part of a sulfonate group507/261, Organic component contains ether linkage (e.g., PEG ether, etc.)507/936Flooding the formationExaminersPrimary: Guynn, Herbert B.International ClassesC09K 8/60 (20060101)C09K 8/58 (20060101) C09K 8/70 (20060101) C09K 8/588 (20060101) AbstractThiourea functions as a solution viscosity stabilizer in aqueous compositions comprising thiourea, nonionic polymers such as polyalkylene oxides and anionic surfactants such as petroleum sulfonates. The aqueous compositions are useful in connection with fluid-drive oil recovery processes, processes for drilling, completing, or working over wells, or the like processes in which a thickened fluid is injected into or brought into contact with a subterranean earth formation. |
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