Preparation and application of targeted response nanocapsules for oil displacement

Abstract

Based on the purpose of forming a new method to improve the oil recovery of low-permeability reservoir, this paper proposes the concept of “intelligent nanocapsules flooding” and develops an intelligent targeted oil displacement agent. The intelligent nanocapsule is a new way to embed surfactant into polymer, which has the advantage of avoiding invalid loss of surfactant in the capsule. In this paper, nanoscale silicon dioxide was prepared by sol–gel method, Janus silica nanoparticles were synthesized by Pickering emulsion preparation, and a Janus functional particle with targeted migration was obtained by coupling agent modification. The amphiphilic temperature responsive polymer AP-g-PNIPAAM was synthesized by atom transfer radical polymerization. The capsule wall prepared in this paper has temperature sensitivity, and Janus functional particles in the core play a targeted role. The oil displacement experiments were carried out on five parallel core models with different grade differences. The results show that when the permeability grade of the parallel combined model rises from 2.05 to 21.57, the oil recovery of Janus intelligent microcapsule dispersion system also increases from 11.16% to 20.75%, with an increase rate of 9.59%. The research results of this paper are helpful to promote the further development of low permeability reservoir.