Nano-encapsulated triggered-release viscosity breaker

摘要

A method for the encapsulation and triggered-release of water-soluble or water-dispersible materials. The method comprises a) providing an amount of electrolyte having a charge, b) providing an amount of counterion having a valence of at least 2, c) combining the polyelectrolyte and the counterion in a solution such that the polyelectrolyte self-assembles to form aggregates, d) adding a compound to be encapsulated, and e) adding nanoparticles to the solution such that nanoparticles arrange themselves around the aggregates. Release of the encapsulated species is triggered by disassembly or deformation of the microcapsules though disruption of the charge interactions. This method is specifically useful for the controlled viscosity reduction of the fracturing fluids commonly utilized in the oil field.

主权项

1. A method of servicing a wellbore in a subterranean formation comprising:
(a) preparing a wellbore servicing a fluid comprising a nanoencapsulate containing a wellbore servicing additive, wherein the nanoencapsulate is prepared by:
i) providing an amount of a polyelectrolyte having a charge;ii) providing an amount of a counterion having a valence of at least 2;iii) combining the polyelectrolyte and the counterion in a solution such that the polyelectrolyte self-assembles to form aggregates;iv) adding to the aggregates the wellbore servicing additive to be encapsulated; andv) adding nanoparticles to the solution such that the nanoparticles arrange themselves around the aggregates to form nanoencapsulates that encapsulate the wellbore servicing additive; and (b) introducing the wellbore servicing fluid to the wellbore, wherein the wellbore servicing additive is released from the nanoencapsulates into the wellbore and/or surrounding formation and wherein the release of the wellbore servicing additive occurs following the addition of a salt solution to the wellbore servicing fluid in an amount effective to produce deformation of the nanoencapsulates.