Aphron-containing well drilling and servicing fluids
Patent 5881826 Issued on March 16, 1999. Estimated Expiration Date: 
February 13, 2017. 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.
February 13, 2017. 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 ReferencesPolymer enhanced foam drilling fluid Foamed gel completion, workover, and kill fluid Foamable drilling fluid and methods of use in well drilling operations Brine fluids having improved rheological charactersitics Patent #: 5728652 InventorApplicationNo. 800727 filed on 02/13/1997US Classes:175/72, Prevention of lost circulation or caving507/102, Contains intended gaseous phase at entry into wellbore507/202Contains intended gaseous phase at entry into wellboreExaminersPrimary: Bagnell, DavidAttorney, Agent or FirmInternational ClassC09K 007/02AbstractThe invention provides a method and fluid for drilling or servicing a well in a subterranean formation containing lost circulation zones or depleted, low pressure reservoirs. A method of decreasing the density of the fluid circulated in a borehole, decreasing the invasion of fluid into formations contacted by the fluid, or decreasing the lost circulation potential of the fluid is provided by using as the fluid an aqueous liquid having dispersed therein a polymer which increases the low shear rate viscosity of the fluid to the extent that the thixotropic index of the fluid is at least about 10 and a surfactant, and wherein the fluid contains aphrons preferably generated by the turbulence and pressure drop as the fluid exits the drill bit in the vicinity of the formation.Other References
Field of SearchUsing specific materialsPrevention of lost circulation or caving Contains intended gaseous phase at entry into wellbore Contains intended gaseous phase at entry into wellbore 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 carbons |
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