Shale-stabilizing drilling fluid additives
CA 1328992 C · Owner: Wingrave, James Allan · Inventors: Palmer, Charles Francis Jr.; Carter, Thomas Scott; Wingrave, James Allan
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Additive compositions and aqueous drilling fluids which impart improved wellbore stability in drilling shale formations consisting essentially of one or more water-soluble high molecular weight polymers capable of forming relatively strong nucleophilic sites when treated with base and one or more potassium salts which have sufficient alkalinity to raise the pH of the resultant drilling fluid to above 9.0, but whose anions are relatively weak nucleophiles compared to the polymeric nucleophilic sites.
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
- Granted May 3, 1994. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended May 3, 2011.
- 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.