Methods for producing seawater based, high temperature viscoelastic surfactant fluids with low scaling tendency
AssigneeSaudi Arabian Oil Company
InventorsLeiming Li, Feng Liang, Tao Chen
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Abstract
Embodiments of the present disclosure are directed to a method of producing a viscoelastic surfactant (VES) fluid, the VES fluid comprising desulfated seawater. The method of producing the VES fluid comprises adding an alkaline earth metal halide to seawater to produce a sulfate precipitate. The method further comprises removing the sulfate precipitate to produce the desulfated water. The method further comprises adding a VES and one or more of a nanoparticle viscosity modifier or a polymeric modifier to the desulfated seawater. Other embodiments are directed to VES fluids that maintain a viscosity greater than 10 cP at temperatures above 250° F.
Claims6
A viscoelastic surfactant fluid comprising:
- a viscoelastic surfactant comprising the general formula:
- where R1 is a saturated or unsaturated hydrocarbon group of from 17 to 29 carbon atoms, R2 and R3, are each independently selected from a straight chain or branched alkyl or hydroxyalkyl group of from 1 to 6 carbon atoms, R4 is selected from H, hydroxyl, alkyl or hydroxyalkyl groups of from 1 to 4 carbon atoms;
- k is an integer of from 2-20;
- m is an integer of from 1-20;
- and n is an integer of from 0-20;
- at least one polymeric viscosity modifier with a weight average molecular weight of from 250,000 g/mol to 40,000,000 g/mol;
- desulfated seawater;
- and
- at least one stabilizing calcium salt.
Dependencies are inferred from the claim text.