High performance water-based drilling mud and method of use
US7192907B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 3, 2003 |
| Grant date | Mar 20, 2007 |
| Priority date | — |
| Expiry date | May 23, 2024 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K2208/12
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A water based drilling fluid for use in drilling a subterranean well through a subterranean formation that swells in the presence of water, the drilling fluid is formulated to include: an aqueous based continuous phase; a weigh material; a shale encapsulator and an optional shale hydration inhibition agent. The shale encapsulator has the formula: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 amide; R, R′ and R″ are independently selectable C1–C3 alkyl; and B− is a charge balancing anion to the quaternary amine. The shale encapsulator and the optional shale hydration inhibition agent 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, such conventional additives may include: fluid loss control agents, alkaline reserve and other pH control agents, bridging agents, lubricants, anti-bit balling agents, corrosion inhibition agents, surfactants and solids suspending agents as well as mixtures and combination of the…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.