Patent ID: 9739132
Date: 2017-08-22
CPC Classifications: C09K,E21B

Claim:
1. A well treatment method comprising: forming a well treatment fluid by combining ingredients including an aqueous-based fluid, a carboxymethyl hydroxyethyl cellulose (CMHEC) polymer, and a crosslinker, the aqueous-based fluid containing produced water, the well treatment fluid having a total dissolved solids (TDS) content of at least 100,000 ppm, and the CMHEC polymer exhibiting a degree of substitution (DS) of 0.3 to 0.5 and a molar substitution (MS) of 2.0 to 2.5; crosslinking the CMHEC polymer in the aqueous-based fluid at a pH of at least about 6 using the crosslinker, the crosslinking increasing viscosity of the well treatment fluid to a sustained viscosity of greater than or equal to about 100 cP at a shear rate of 100 sec treating a well with the well treatment fluid at a temperature of at least about 200° F. while the well treatment fluid exhibits the sustained viscosity, the well treatment fluid exhibiting a property of stabilizing the sustained viscosity of greater than or equal to about 100 cP at a shear rate of 100 sec