Cellulose ether-polyacrylamide aqueous gels
Patent 4043921 Issued on August 23, 1977. Estimated Expiration Date: 
August 23, 1994. 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.
August 23, 1994. 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 3502149 3727687 3727688 3749172 3785437 InventorsAssigneeApplicationNo. 05/656772 filed on 02/09/1976US Classes:507/113, Carboxyalkylcellulose (e.g., CMC, CMHEC, etc.)507/120, Nitrogen is attached directly or indirectly to the acrylic acid monomer or derivative by nonionic bonding (e.g., acrylamide, acrylonitrile, etc.)507/131, Oxygen is attached directly or indirectly to carbon by nonionic bonding507/215, Carboxyalkylcellulose (e.g., CMC, CMHEC, etc.)507/225, Nitrogen is attached directly or indirectly to the acrylic acid monomer or derivative by nonionic bonding (e.g., acrylamide, acrylonitrile, etc.)507/903, CROSSLINKED RESIN OR POLYMER507/935ENHANCED OIL RECOVERYExaminersPrimary: Guynn, Herbert B.AbstractImprovements in secondary recovery operations for the recovery of oil, and improvements in well-drilling operations, are accomplished through the use of aqueous gels exhibiting high gel strength prepared from water and a mixture of (a) at least one cellulose ether, e.g., carboxymethyl cellulose, and (b) at least one polyacrylamide. |
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