Use of selected ester oils of low carboxylic acids in drilling fluids
CA 2047697 C · Owner: Burbach, Frank · Inventors: Von Tapavicza, Stephan; Burbach, Frank; Mueller, Heinz
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention describes the use of selected esters fluid, at room temperature and with flash points above 80°C of, C1-5-monocarboxylic acids and mono- and/or polyfunctional alcohols as the oil phase, or a component of the oil phase of invert drilling muds which are suitable for environment-friendly development of petroleum or natural gas deposits and contain in a continuous oil phase a dispersed aqueous phase together with emulsifiers weighting agents, fluid-loss additives and preferably further conventional additives. In a further embodiment the invention relates to invert drilling fluids of the type described, which are characterized in that the oil phase contains esters from …
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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 March 1, 1990 and granted July 31, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 1, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 1, 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
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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.