US 7,517,835 B2
Surfactant-polymer compositions for enhancing the stability of viscoelastic-surfactant based fluid
Robert L. Horton, Sugar Land, Tex. (US); Bethicia B. Prasek, Houston, Tex. (US); Frederick B. Growcock, Houston, Tex. (US); David P. Kippie, Katy, Tex. (US); John W. Vian, Deer Park, Tex. (US); Kamila B. Abdur-Rahman, Houston, Tex. (US); and Morris Arvie, Houston, Tex. (US)
Assigned to M-I LLC, Houston, Tex. (US)
Filed on Nov. 14, 2005, as Appl. No. 11/273,350.
Application 11/273350 is a continuation of application No. 10/620041, filed on Jul. 15, 2003, granted, now 7,157,409.
Claims priority of provisional application 60/319575, filed on Sep. 25, 2002.
Prior Publication US 2006/0100109 A1, May 11, 2006
This patent is subject to a terminal disclaimer.
Int. Cl. C09K 8/60 (2006.01); C09K 3/00 (2006.01)
U.S. Cl. 507—222  [507/240; 507/277; 516/73] 19 Claims
 
1. A wellbore fluid comprising:
an aqueous based continuous phase;
a viscoelastic surfactant; and
a surfactant-polymer compound soluble in an aqueous solution, the surfactant-polymer compound having a hydrophobic backbone and a plurality of hydrophilic functional groups attached to the hydrophobic backbone,
wherein the hydrophobic backbone is the reaction product of one or more molecules having polymerizable alkene or alkyne functional groups;
wherein the hydrophilic functional groups are selected from the group consisting of zwitterionic surfactant functional groups, anionic surfactant functional groups, cationic surfactant functional groups, and nonionic surfactant functional groups; and
wherein the combination of the viscoelastic surfactant and surfactant-polymer compound form micellar assemblies.