Research on In-Depth Profile Control of a Multiphase Foam System

摘要

A multiphase foam system (MFS), a new in-depth profile control agent, integrates the merits of a microgel system and a foam system. This article studies the compatibility of a microgel with foam, injection behaviors of foam and microgel, and enhanced oil recovery (EOR) situations of a foam system, microgel system, and MFS. According to the experiments, the MFS has the best stability in air when the concentration of the microgel is 5,000 mg/L. The injection pressure of MFS exhibits a "step" ascending trend; in addition to absorbing on the rock pore surface, the microgels can block the formations by forming bridges in the pore throats. A large pressure fluctuation, which enhancs the oil recovery, occurs in the injection process of MFS. The oil recovery of MFS is higher than that of the foam system and the microgel system, and after MFS flooding, the ultimate oil recovery of a low-permeability core is higher than that of a high-permeability core.