油气地质与采收率2018，Vol.25Issue(3)：107-111,5.DOI:10.13673/j.cnki.cn37-1359/te.2018.03.016
CO2驱沥青质沉积量对致密砂岩油藏采收率的影响机理
Study on influencing mechanism of asphaltene precipitation on oil recovery during CO2 flooding in tight sandstone reservoirs
摘要
Abstract
In order to reveal the influencing mechanism of asphaltene precipitation on oil recovery during CO2 flooding in the tight sandstone reservoirs,three kinds of crude oil samples with different asphaltene contents and low-permeability artificial cores(epoxy resin cemented quartz sand)were selected for flooding tests.The flooding tests were carried out by stimulating actual formation temperature and pressure.The effect of asphaltene precipitation on the oil recovery of different scales of pore throat was analyzed by nuclear magnetic resonance (NMR) technique.The results show that the amount of asphaltene precipitation is proportionate to asphaltene contents of the crude oil during flooding.It also increases with the increasing CO2 injection volume.At the same time,the oil recovery will be affected by asphaltene,which decreases with the increasing precipitation amount.The results of NMR test show that the asphaltene precipitation had little effect on the oil recovery of the larger pore-throats (2.0-200.0 ms).However,the asphaltene precipitation produced a certain degree of clogging in the smaller pore-throats (0.1-2.0 ms),resulting in the remaining oil being difficult to be recovered and ultimately affecting the overall recovery.关键词
致密砂岩/CO2驱/沥青质沉积/采收率/核磁共振技术/影响机理Key words
tight sandstone/CO2 flooding/asphaltene precipitation/oil recovery/NMR/influencing mechanism分类
能源科技引用本文复制引用
王琛,李天太,高辉,高媛,赵金省,窦亮彬..CO2驱沥青质沉积量对致密砂岩油藏采收率的影响机理[J].油气地质与采收率,2018,25(3):107-111,5.基金项目
国家自然科学基金项目“非常规致密砂岩油藏超临界CO2驱CO2-原油-微纳米级孔喉缝系统的相互作用机理研究”(51774236)和“酸性气体侵入井筒在钻井液内赋存状态及对瞬态流动影响研究”(51604224),中国石油科技创新基金项目“致密砂岩储层有效孔喉缝系统与致密油赋存评价新方法研究”(2017D-5007-0104). （51774236）
