Methods for controlling the rheological properties of viscoelastic surfactants based fluids
AssigneeSchlumberger Technology Corporation
InventorsJesse Lee, Erik Nelson, Kevin England, Philip Sullivan
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Abstract
It was found that the addition of polymers to viscoelastic surfactant base system allows to adjust the rheological properties of the base fluid. Depending in particular on one side of the ratio of the concentration of added polymer and the concentration of viscoelastic surfactant and on the other side of the molecular weight of the added polymer, the same polymer—or the same type of polymer—may perform different functions such as viscosity enhancer, viscosity breaker or viscosity-recovery enhancer.
Claims72
A method of treating a subterranean formation comprising the steps of:
- (a) injecting down a well an aqueous fluid comprising a thickening amount of a viscoelastic surfactant;
- (b) providing an encapsulated polymer additive that causes a change in rheology of the fluid under downhole conditions.
A method of treating a subterranean formation comprising the steps of:
- (a) injecting down a well an aqueous fluid comprising a thickening amount of a viscoelastic surfactant;
- (b) providing a polymer additive selected from the group consisting of sulfonated polynaphthalenes, sulfonated polystyrenes, sulfonated styrene/maleic anhydride polymers, that causes a change in rheology of the fluid under downhole conditions.
Dependencies are inferred from the claim text.