High performance water-based drilling mud and method of use
US7497262B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 8, 2007 |
| Grant date | Mar 3, 2009 |
| Priority date | — |
| Expiry date | Feb 8, 2027 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K2208/12
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A method of forming a subterranean well and a method of reducing the swelling of shale clay during the drilling of the subterranean well. The method features the use of a water based drilling fluid, wherein the drilling fluid is formulated to include: an aqueous based continuous phase; a weight material; an optional shale hydration inhibition agent and a shale encapsulator. The shale encapsulator has the formula:in which x and y have a value so that the molecular weight of the cation is in the range of about 10,000 to about 200,000 AMU; A is selected from C1-C6 alkyl, C2-C6 ether or C2-C6 amide; R, R′and R″are independently selectable C1-C3 alkyl; and B−is a charge balancing anion to the quaternary amine. The shale hydration inhibition agent and the shale encapsulator may be present in sufficient concentrations to reduce the swelling of the subterranean formation in the presence of water. Conventional additives may be included into the formulation of the drilling fluid, including: fluid loss control agents, alkaline reserve and other pH control agents, bridging agents, lubricants, anti-bit balling agents, corrosion inhibition agents, surfactants, solids suspending agents, and mixtu…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.