CO_2,N_2与蒸汽混合增效作用研究

Research on mixing efficiency of carbon dioxide, nitrogen and steam

尽管多元热流体热采技术在海上应用中取得了显著效果,但对其中CO2,N2与蒸汽等组分混合增效作用的认识尚不清楚。通过室内岩心模拟实验,研究了不同注入温度条件下注入相同热量时4种方式(蒸汽、蒸汽+CO2、蒸汽+N2、蒸汽+CO2+N2)的驱替效果。实验结果表明:在300℃条件下,蒸汽+CO2驱替效果最好,阶段采收率可达57.7%;其次为蒸汽+CO2+N2,阶段采收率可达53.3%;最差为蒸汽。结合实验数据,应用灰色系统理论中的关联分析方法,对不同温度下相关的3个因素进行分析,结果表明蒸汽+N2的影响最大,说明在CO2,N2与蒸汽混合增效作用中,N2的作用非常显著。该研究为下步多元热流体组分优化提供了技术依据。

Thermal recovery technology of multiple heat fluid has significant eftt in the application of offshore oilfield. But it is not clear to understand the role of the mixing efficiency of the carbon dioxide, nitrogen and steam and other components. The displacement effects are studied by the indoor core simulation after injecting steam, steam＋ nitrogen, steam ＋ carbon dioxide, steam ＋ carbon dioxide ＋ nitrogen under the same quantity of heat. The experimental results show that the displacement effect of steam ＋ carbon dioxide is best, the phase recovery factor can reach 57.7% at 300 ℃. Followed by steam ＋ carbon dioxide ＋ nitrogen, the phase recovery factor can reach 53.3% and the worst one is steam displacement. The three relevant factors at different temperatures are analyzed combined with the principle of correlation analysis in grey theory and experimental data. The result indicates the influence of steam ＋ nitrogen is the largest, showing that the effect of nitrogen in multiple heat fluid is very obvious. This study can provide the technical basis for the next step optimization of muhiple heat fluid components.