Self-diverting pre-flush acid for sandstone
CA 2491934 C · Owner: Schlumberger Technology Corporation · Inventors: Fu, Diankui
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Embodiments of the Present Invention relate to a reversibly thickenable nonpolymeric fluid that has low viscosity in strong acid gels when the acid , concentration is reduced by only a small amount and is subsequently , decomposed by the acid. In particular it relates to an aqueous mixture of zwitterionic surfactants, inorganic acids and organic acids Most particularly , it relates to the use of this fluid as a diverting agent for easily-damaged sandstones, for example prior to matrix acidizing.
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 July 9, 2003 and granted April 24, 2012. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 9, 2023.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 9, 2025.
- 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.