Drilling with low viscosity fluids
US3948782A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 10, 1973 |
| Grant date | Apr 6, 1976 |
| Priority date | — |
| Expiry date | Sep 10, 1993 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC10N2050/01
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.