Abstract:

Injection pattern and displacement efficiency of NTCP foam system have been studied, which is made of 0.2%NAPS hydrophobic associating polymer as foam stabilizer, 0.15% surfactant as foaming agent and industrial nitrogen in accordance with certain proportion. The NTCP foam system has high re-
sistance coefficient and low residual resistance coefficient. Under the geological condition of Wenmingzai oilfield in Zhongyuan oilfields, simulation experiment shows that the foam system hashigh displacement efficiency, ability of control profile and low damages to low permeable formation. Injecting 0.8 PV in single core experiment, the displacement efficiency of foam flooding is 17.9%-28.7% higher than that of water flooding.Injecting 0.8 PV in parallel core experiment, when permeability contrast is 14.1 and 38.2 respectively, the displacement effi-ciency of foam flooding is 44.0% and 28.6% respectively high-er than that of water flooding.

Key words: NTCP foam, alternate injection, physical simulation, oil displacement efficiency