西南石油大学学报（自然科学版）2012，Vol.34Issue(3)：89-97,9.DOI:10.3863/j.issn.1674-5086.2012.03.013
注CO2前置段塞+N2顶替提高采收率机理
Mechanism Research of Enhancement Oil Recovery by CO2 Slugs Pushed by N2
摘要
Abstract
SJ oil reservoir's permeability is low and its natural energy is poor. However, because of the inadequate CO2 source and the poor resistance of the pipelines to CO2-corrosion, the continuous CO2 injection is unavailable in the field. In that case, another unproved strategy is the replacement of the continuous CO2 injection by CO2 slugs pushed by N2. Based on the formation hydrocarbon characteristics of the pilot test block, we try to compare the mechanism of CO2 slugs drive pushed by N2 with the continuous CO2 drive. After we tested the recovery percent and minimum miscibility pressure (MMP) of CO2 slugs drive pushed by N2 and CO2 drive by slim tube experiments, our research are the multiple contact simulation of CO2 drive and N2 drive and the one-dimensional simulation of long slim tube of CO2 slugs pushed by N2. We analyse the intermiscibility of gas slug and the crude oil, the interfacial tension between gas phase and liquid phase, the concentration of C2-C6 in the two phases, density and viscosity of such two phases. The simulation results indicate no serious diffusion and dispersion of CO2 and N2 occur when CO2 slug pushed by N2 displaces the crude oil during the long slim tube test. The CO2 concentration of the multicontect front is in a high level to keep a stable miscible displacement front to drive oil. CO2 slugs pushed by N2 can gain the same oil recovery with continuous CO2 flooding in the same volume of gas injection. Such gas slug displacementreduce the amount of CO2, so it can glow the CO2-corrosion to the pipelines caused by the continuous CO2 injection. The cognition provides inspiration function for the development and improvement CO2-EOR.关键词
低渗油藏/CO2-EOR/多级接触混相驱/CO2前置段塞N2顶替Key words
low permeability reservoir/ CO2-EOR/ multicontact miscibility/pre-CO2-slug pushed by N2分类
能源科技引用本文复制引用
孙扬,杜志敏,孙雷,潘毅,汤勇..注CO2前置段塞+N2顶替提高采收率机理[J].西南石油大学学报（自然科学版）,2012,34(3):89-97,9.基金项目
十二五国家重大专项子课题研究内容(2011ZX05016-005-2). （2011ZX05016-005-2）
