具有可控凹坑结构的非对称球形纳米颗粒的制备及其应用OA

To solve the problems of poor stability and limited application of oil-based foams,asymmetric spherical nanoparticles with controllable pit structures were prepared.This study explored the morphology regulation mechanism of the nanoparticles,clarified their stabilization mechanism for oil-based foams,and verified their potential in enhanced oil recovery.The results indicate that nanoparticles etched for 5-10 d form effective pit structures,and their oleophobicity and oil-based foam stability in low-surface-tension oil phases are significantly improved compared with those of unetched nanoparticles.Nanoparticles with insufficient etching(18 h)show no performance difference from unetched ones,while over-etched nanoparticles(15 d)have an unstable Cassie-Baxter state of aggregates due to pit morphology damage,which results in reduced foam stability.Core flooding experiments reveal that gas-oil co-injection without nanoparticles results in only a quite limited improvement in oil recovery,whereas oil-based foams generated by gas-oil co-injection with nanoparticles etched for 5-10 d can effectively plug high-permeability layers and delay gas channeling under the same permeability contrast.