Experimental Investigation of Nanolaponite Stabilized Nitrogen Foam for Enhanced Oil Recovery

In this study, a modified nanolaponite was applied with foaming agent XR-1 to form a foam flooding system for enhanced oil recovery. The system formula was screened as 0.40 wt % XR-1 + 0.25 wt % nanolaponite, and both the foaming volume and the drainage half-time reach satisfactory values using the formula, proving the synergistic effect of the nanolaponite and XR-1 for the contribution to nitrogen foam properties. Micromodel displacement experiments were performed to investigate the microstatic stability and displacement behavior of this system. Results show high microstatic stability of nitrogen foam within the test time when XR-1 and nanolaponite are applied together. According to the matching rule between the foam bubble and pore throat, the nanolaponite stabilized nitrogen foam belongs to the ideal bubble's throat blocking model, which can significantly improve the conformance efficiency. Moreover, the obvious oil dispersion and emulsification phenomena also contribute to the sweep efficiency. Single and double sand pack core displacement experiments were conducted to study the enhanced oil recovery (EOR) ability of this system in homogeneous and heterogeneous reservoirs, respectively. Results display that the nanolaponite stabilized nitrogen foam has favorable EOR ability, and the incremental oil recovery is considerable in both single and double core displacement experiments.