Fluid additive and method for treatment of subterranean formations
CA 2010901 C · Owner: Halliburton Company · Inventors: Himes, Ronald E.; Simon, David E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method of substantially preventing the adsorption of polysaccharides or removing polysaccharides from clay surfaces in subterranean formations which are present as a result of contact by gravel packing, fracturing or other treatment fluids, by contacting the formation with a treatment fluid containing at least one member selected from the group consisting of tetraalkylammonium halides wherein the alkyl radical is selected from methyl, ethyl propyl and, butyl radicals and trimethylammonium halides present in an amount sufficient to substantially remove any polysaccharides adsorbed by said clays whereby the permeability of the formation is substantially maintained.
Read the whole patent
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 February 26, 1990 and granted April 11, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 26, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 26, 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.