富气混相驱气窜界定方法及其在阿尔及利亚某油田的应用  

Study on determination of gas channeling during enrich gas miscible flooding and its application in certain oilfield of Algeria

作　　者：魏旭光[1] 

机构地区：[1]中国石化集团国际石油勘探开发有限公司,北京100081

出　　处：《油气地质与采收率》2012年第1期75-78,116,共4页Petroleum Geology and Recovery Efficiency

摘　　要：气窜对富气混相驱提高原油采收率有较大的影响。以阿尔及利亚某油田富气混相驱为例,介绍了较为实用的3种气窜界定方法,即气油比变化率判断法、C6+摩尔分数变化率判断法和(C3+C4+)摩尔分数变化率判断法,并通过数值模拟对气窜前后渗流场的变化规律进行了研究,加深了对气窜界定的认识。此外,对可能影响气窜界定的注气量、注气速度和注入气组分等因素进行了敏感性分析。结果表明,注气量、注气速度和注入气组分对气窜界定均无明显影响,气油比或气油比变化率能够较好地界定气窜,特征组分的摩尔分数变化率可以作为参考。Gas channeling has a significant influence on the oil recovery increment for enrich-gas miscible flooding.Major reasons are reservoir heterogeneity,enrich-gas's viscosity less than oil's which both might cause the injected enrich-gas breakthrough too early.Once the gas channeling evolves into gas passage,the swept efficiency of the injected gas does not increase very much;all of these affects EOR.Hence,how to determinate the gas channeling is an inevitable problem during enrich-gas displacement.This paper introduces three practical methods to determine gas channeling with the enrich-gas miscible flooding in an Algeria oilfield.Numerical simulation approach has been applied to analyze variation of the seepage field before and after gas channeling,which have enhanced our comprehension of the gas channeling determination.Besides,sensitivity analysis has been carried through sever-al factors;gas injected volume,gas injected rate and enrich-gas composition.Results show that these factors do not affect the determination of gas channeling evidently.GOR and GOR rate of change can determinate the gas channeling readily,the characteristic component's mole rate of change can be a reference.

关 键 词：富气混相驱 油藏非均质性 气窜界定 数值模拟 敏感性分析 

分 类 号：TE357.42[石油与天然气工程—油气田开发工程]