Drilling fluid additives for use in hard brine environments
Patent 4743383 Issued on May 10, 1988. Estimated Expiration Date: 
November 24, 2006. 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.
November 24, 2006. 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 2578888 2862881 2885358 3028333 3062740 3072569 3127343 3899431 Drilling with low viscosity fluids Drilling fluids InventorsAssigneeApplicationNo. 06/934388 filed on 11/24/1986US Classes:507/110, Organic component is carbohydrate or derivative thereof (e.g., sugar or gum, such as galactomannan, xanthan, etc.) or carboxylic acid ester of an alcohol which has five or more hydroxy groups bonded directly to carbons507/121, Sulfur is attached directly or indirectly to the acrylic acid monomer or derivative by nonionic bonding (e.g., acrylamidoalkane sulfonates, etc.)507/126, Organic component is asphalt or a component or derivative thereof507/134, Organic component contains sulfur 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.)507/137, Organic component contains a carbocyclic group (e.g., cyclic alkyl, aromatic, tall oil, etc.)507/139Organic component contains an alcohol groupExaminersPrimary: Guynn, Herbert B.Attorney, Agent or FirmInternational ClassesC09K 8/035 (20060101)C09K 8/02 (20060101) AbstractA drilling fluid additive is disclosed which will prevent water loss into subterranean formations during the drilling of oil and gas wells in hard brine environments. The drilling fluid additive comprises a hydrocarbon, an anionic surfactant, an alcohol, a sulfonated asphalt, a biopolymer, and optionally an organophilic clay, poly(N-vinyl-2-pyrrolidone-co-sodium-2-acryamido-2-methylpropane sulfonate, and water. |
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