Rheology Modifiers
AssigneeSchlumberger Technology Corporation
InventorsYiyan Chen, Jesse Lee, Mathew Samuel
Life of this patent
Estimating the term…
Abstract
A method for increasing the rate of shear rehealing of fluids made with cationic, zwitterionic, and amphoteric viscoelastic surfactant fluid systems by adding an effective amount of a polymeric rheology enhancer selected from polypropylene glycols and block copolymers of polypropylene glycol and polyethylene glycol. For applications in which rapid shear rehealing is required, the rheology enhancer allows fluids to be made and used at lower viscoelastic surfactant concentrations. Preferred surfactants are betaines and quaternary amines. The fluids are useful in oilfield treatments, for example fracturing and gravel packing.
Claims36
An oilfield treatment method comprising:
- a. providing a fluid comprising a viscoelastic surfactant selected from the group consisting of zwitterionic, amphoteric, and cationic surfactants and mixtures thereof,
- b. adding to said fluid a rheology enhancer in a concentration sufficient to decrease the shear rehealing time of said fluid, said rheology enhancer selected from the group consisting of polypropylene glycols and block copolymers of polypropylene glycol and polyethylene glycol;
- and
- c. injecting said fluid down a well.
A method of increasing the rate of shear rehealing of a viscoelastic fluid made with a viscoelastic surfactant comprising:
- a. providing a fluid comprising a viscoelastic surfactant selected from the group consisting of zwitterionic, amphoteric, and cationic surfactants and mixtures thereof, and
- b. adding to the fluid a rheology enhancer in a concentration sufficient to increase the rate of shear rehealing of said fluid, said rheology enhancer selected from the group consisting of polypropylene glycols and block copolymers of polypropylene glycol and polyethylene glycol.
An oilfield treatment fluid comprising:
- a. a viscoelastic surfactant selected from the group consisting of zwitterionic, amphoteric, and cationic surfactants and mixtures thereof,
- b. a rheology enhancer in an amount sufficient to increase the rate of shear rehealing of said fluid, said rheology enhancer selected from the group consisting of polypropylene glycols and block copolymers of polypropylene glycol and polyethylene glycol, and
- c. a liquid carrier.
Dependencies are inferred from the claim text.