The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 06, 1976
Filed:
Sep. 10, 1973
Karl D Dreher, Littleton, CO (US);
William B Gogarty, Littleton, CO (US);
Marathon Oil Company, Findlay, OH (US);
Abstract
An improved method of drilling a well is effected by circulating in the well a drilling fluid containing lamellar micelles at flow rates predetermined to produce retro-viscous behavior in the drilling fluid at noncryogenic temperatures. The composition contains 4-15% surfactant (preferably petroleum sulfonate having an average equivalent weight of 350-525), 30-70% liquid hydrocarbon, 15-66% water and optionally up to 20% cosurfactant (preferably an alcohol containing 1-20 carbon atoms) and/or electrolyte (preferably inorganic salt) and the micelles have an axial ratio of at least 3.5. Preferably, the composition has a viscosity of at least 75 cp at a shear rate of 10.sup.-.sup.1 seconds at 23.degree.C. The composition is substantially optically clear, phase stable, birefrigent, and the flow properties are such that substantially large increases in flow rates, e.g., 20-fold, can be realized at very small pressure increases, e.g., 5%. Additional additives to impart desired drilling properties can be included with the composition.