%0 Journal Article %A Tang, Shanfa %A Tian, Lei %A Lu, Jun %A Wang, Zhengxin %A Xie, Yunlong %A Yang, Xiaopei %A Lei, Xiaoyang %D 2018 %I Begell House %K chemical EOR, surfactant, foam flooding, porous media %N 3 %P 197-208 %R 10.1615/JPorMedia.v21.i3.10 %T IMPROVEMENT OF OIL RECOVERY THROUGH A NOVEL LOW-TENSION FOAM FLOODING AFTER ENHANCED OIL RECOVERY PROCESSES %U https://www.dl.begellhouse.com/journals/49dcde6d4c0809db,0292bfbe0994e49a,4db4513936ef88ca.html %V 21 %X Shuanghe oil field is a sandstone reservoir characterized by high water cut, poor sweep efficiency, and high heterogeneity with a long history of water flooding. The field has completed polymer flooding and is now under surfactant-polymer (SP) flooding. Although the SP flood is close to the end, the residual oil saturation is estimated to still be about 46%–50% original oil in place. Therefore, future development of such reservoirs requires an efficient method to recover residual oil to be developed. In this paper, we presented a new high-temperature resistant nitrogen foam system that gives a low oil/water interfacial tension and improves the sweep efficiency after SP flooding. The optimal foam formulation is 0.4 wt % foam agent and 0.2 wt % foam stabilizer, which has a low interfacial tension (IFT) (5.31×10−2 mN/m) and high foam stability index (> 10,000 mL min). The optimal injection parameter of foam flooding is the coinjection of gas and solution, gas-to-liquid ratio of 1.5:1.0, foam injecting size of 0.5 pore volumes, and an injection rate of 1.0 mL/min. Compared with the other three enhanced oil recovery processes in a series of four oil displacement experiments, the foam flood showed the best performance and highest oil recovery. An additional core flood was also done to mimic the field processes. The results showed the foam flood can effectively recover residual oil after water, polymer, and SP flooding. All the experimental results indicate this low-tension foam flooding could find applications in the Shuanghe oil field. %8 2018-05-07