Use of selected ester oils in water-based drilling fluids of the o/w emulsion type and corresponding drilling fluids with improved ecological acceptability
CA 2058636 C · Owner: Herold, Claus-Peter · Inventors: Mueller, Heinz; Von Tapavicza, Stephan; Fues, Johann Friedrich
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The use is disclosed of water-dispersible esters which are fluid or at, least plastically deformable at working temperature and have flash points of at least 80°C, from saturated and/or unsaturated carboxylic acids with up to 36 carbon atoms and mono- and/or polyhydric aloohols as at least the main constituent of the dispersed oil phase of water-based O/W-emulsion drilling fluids which are suitable for the environmentally friendly development of geological formations and which contain, if desired, insoluble, finely particulate weighting agents for the formation of water-based O/W-emulsion drilling mode and/or further additives, such as emulsifiers, fluid-loss additives wetting agents, …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed May 7, 1990 and granted April 3, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 7, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 7, 2012.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.