低渗油藏非纯 CO₂近混相驱及实现条件研究

Study on the Realization Conditions of Impure CO₂ Near-miscible Flooding in Low Permeability Reservoir

陈 浩 张贤松 唐 赫 杨 光 王 全

CHEN Hao ZHANG Xiansong TANG He YANG Guang WANG Quan

为明确非纯 CO2近混相驱的压力区域和实现条件， 综合采用细管实验和细管模拟方法， 分别从物理化学和工程应用的角度， 建立了基于驱油效率和界面张力的非纯 CO2-原油体系近混相压力区间的综合界定方法， 在传统的最小混相压力 （MMP） 附近划分了一个近混相区域。研究发现， 该区域对应的驱油效率为 85%～ 95%， 对应的界面张力约为 0.001～0.05 mN/m。以秦皇岛 29-2E-5井 1段为例， 该目标油藏典型井在不同 CO2纯度下的近混相压力区间为 26.52～32.9 MPa， 约为 MMP的 0.8～1倍， 实现近混相驱的 CO2纯度下限为 64%。图 3表 2参 13

To determine the pressure interval and realization conditions of impure CO2 near-miscible flooding，from the perspective of physiochemical and engineering，slim tube test and slim tube simulation were conducted comprehensively to establish the defining method based on the displacement efficiency and interfacial tension（IFT）under different pressures，respectively. A near-miscible region（NMR）was divided from the vicinity of conventional minimum miscible pressure（MMP） . It was shown that the displacement efficiency and IFT of the NMR was 85%—95% and 0.001—0.05 mN/m，respectively. Taken the 1st section of the well QHD 29-2E-5 as an example，the pressure intervals of the NMR was 26.52—32.9 MPa，which was 0.8—1 times MMP；and the lower limit of CO2 content was 64% obtained

10.19346./j.cnki.1000-4092.2017.04.013