Method for correcting lost circulation
Patent 4155410 Issued on May 22, 1979. Estimated Expiration Date: 
June 26, 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 26, 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 ReferencesInventor
AssigneeApplicationNo. 05/919142 filed on 06/26/1978US Classes:175/66, Treating spent or used fluid above ground175/69, Combined liquid and gaseous fluid175/72Prevention of lost circulation or cavingExaminersPrimary: Novosad, Stephen J.Attorney, Agent or FirmInternational ClassesC09K 8/10 (20060101)C09K 8/02 (20060101) E21B 21/06 (20060101) E21B 21/00 (20060101) E21B 21/14 (20060101) AbstractLost circulation in a well occurring during drilling is reduced by aeration of clay-free, non-thixotropic, brine wellbore fluids comprising hydroxyalkyl cellulose and preferably magnesia as a stabilizer. The gas is easily and completely removed from the foam returned to surface with only a conventional degassing and gas busting equipment normally found in a solids removal system. The advantages of the clay-free, non-thixotropic, drilling fluids as known are preserved and the system allows rapid change from aerated to non-aerated fluid as required. | |
