The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 16, 1989
Filed:
Dec. 30, 1987
Krister Holmberg, Molndal, SE;
Eva sterberg, Gothenburg, SE;
Berol Kemi AB, Stenungsund, SE;
Abstract
Novel ether phosphonate surfactants having a branched hydrophobic tail are used in a process for enhanced oil recovery from a subterranean oil reservoir. They combine a high oil-mobilizing capacity with a good tolerance against divalent ions. The ether phosphonate surfactants are summarized by the formula ##STR1## where R.sub.1 and R.sub.2, being the same or different, are hydrocarbons containing 3-18 carbon atoms each and optionally containing functional groups such as ether and hydroxyl; X is an alkyleneoxy group derived from an alkylene oxide having 2-3 carbon atoms; Y is an alkylene group having 1-4 carbon atoms; R.sub.3 is an alkyl group having 1-4 carbon atoms; M.sup.+ is a monovalent cation; n.sub.1 and n.sub.2, being the same or different, are a number from 0 to 4; m.sub.1 and m.sub.2, being the same or different, are 0 or 1, both m.sub.1 and m.sub.2 not being 0 at the same time and m.sub.1 being 1 when n.sub.1 is a number from 1 to 4 and m.sub.2 always being 1 when n.sub.2 is a number from 1 to 4; and p is a number from 0 to 10.