US 6,981,552 B2
Well treatment fluid and methods with oxidized polysaccharide-based polymers
B. Raghava Reddy, Duncan, Okla. (US); Larry S. Eoff, Duncan, Okla. (US); and Eldon Dwyann Dalrymple, Duncan, Okla. (US)
Assigned to Halliburton Energy Services, Inc., Duncan, Okla. (US)
Filed on Mar. 21, 2003, as Appl. No. 10/394,461.
Prior Publication US 2004/0182575 A1, Sep. 23, 2004
This patent is subject to a terminal disclaimer.
Int. Cl. E21B 43/00 (2006.01)
U.S. Cl. 166—294 19 Claims
 
1. A method of treating a subterranean formation penetrated by a wellbore comprising the steps of:
(a) forming a well treatment fluid comprising:
(i) water;
(ii) a chitosan-based polymer; and
(iii) a oxidized polysaccharide-based polymer, which is able to crosslink with the chitosan-based polymer in water and produce a gel having a viscosity of greater than or equal to about 20 cp, wherein from about 1 % to about 25 % of the units of the polysaccharide-based polymer are oxidized; and
(b) contacting the subterranean formation with the well treatment fluid.