杂质气体对二氧化碳驱最小混相压力和原油物性的影响  

Research about the influence of impurities on MMP and crude oil properties for CO_2 flooding

作　　者：尚宝兵[1,2] 廖新维[1] 赵晓亮[1] 蔡振华[3] 李俊飞 何逸凡 苏宪科 

机构地区：[1]中国石油大学(北京)石油工程教育部重点实验室,北京102249 [2]中海石油(中国)有限责任公司天津分公司,天津300452 [3]中海油能源发展股份有限公司工程技术分公司,天津300452 [4]中国石油大庆头台油田开发有限责任公司,黑龙江大庆166500

出　　处：《油气地质与采收率》2014年第6期92-94,98,共4页Petroleum Geology and Recovery Efficiency

基　　金：国家科技重大专项"复杂油气田地质与提高采收率技术"(2011ZX05009);国家"973"计划"二氧化碳减排;存储和资源化利用的基础研究"(2011CB707302)

摘　　要：注入二氧化碳中混有的杂质气体会不同程度地影响二氧化碳驱最小混相压力和原油物性。研究杂质气体含量对二氧化碳驱的影响对制定合理有效的开发方案具有重要意义。利用数值模拟方法,在原油PVT数据拟合的基础上,研究了甲烷与氮气这2种杂质气体的含量对二氧化碳驱最小混相压力的影响,分析了杂质气体对二氧化碳驱原油物性的影响。结果表明,甲烷与氮气会不同程度地增大二氧化碳驱最小混相压力,且氮气对最小混相压力的影响更显著。当注入气的摩尔分数为60%时,纯二氧化碳气体可使原油粘度降低71.9%,体积膨胀系数达1.42;含30%摩尔分数的甲烷注入气使原油粘度降低69.72%,体积膨胀系数为1.41;而含30%摩尔分数氮气的注入气使原油粘度降低65.92%,体积膨胀系数为1.36。对于目标区块,注入二氧化碳中甲烷的临界摩尔分数为5.6%,氮气的临界摩尔分数为2%。Impurities contained in the injected CO2 will exert influence on minimum miscibility pressure(MMP) as well as the crude oil property. It is meaningful to study the influence of impurities on CO2 flooding. Based on PVT data regression, the impact of CH4 and N2on MMP was analyzed with numerical simulation method. Besides, the impact of impurities on crude oil properties was also studied. It shows that the presence of N2 and CH4tends to increase MMP, and the influence of N2 is more notable. When the mole fraction of injected pure CO2 reaches 60%, the oil viscosity reduces by 71.9% and the coefficient of cubic expansion reaches 1.42. But when 30% mole fraction of CH4 is contained in the injected CO2, the oil viscosity reduces by 69.72% and the coefficient of cubic expansion reaches1.41. However, when 30% mole fraction of N2 is contained in the injected gas, the oil viscosity only reduces by 65.92% and the coefficient of cubic expansion is 1.36. For the target block, the critical molar content of CH4 in the injected CO2 is 5.6%, while the critical molar content of N2 is 2%.

关 键 词：二氧化碳驱 甲烷 氮气 最小混相压力 原油物性 临界摩尔分数 数值模拟 

分 类 号：TE357[石油与天然气工程—油气田开发工程]