Transient Foaming Behavior of CO_2-soluble, Viscoelastic Surfactant in Microfluidic Model, Sand Pack and Limestone Core

摘要

Aqueous foam has been demonstrated through laboratory and field experiments as an effective conformance control technique for gas enhanced oil recovery. The use of polymer in an aqueous foam is a common practice to increase the viscosity of the foam liquid phase. Such viscosification improves foam performance by increasing the apparent gas viscosity and reducing the rate of foam coalescence. This study explores the use of worm-like micelles (WLM) as an alternative viscosifying agent to polymer. We utilized a cationic, amine-based surfactant; whose micelles transform from spherical to worm-like conformation at elevated salinity. We found evidence that the presence of WLM could accelerate strong foam generation. The WLM structures also allowed for strong foam generation in a heterogeneous limestone core at high-temperature (120°C) and high-salinity (20 wt.% NaCl).