应用地球化学方法研究断层的渗漏性

Study leakage of fault with geochemical techniques

侯读杰 朱俊章 唐友军 肖中尧 王清华

Hou Dujie Zhu Junzhang Tang Youjun Xiao Zhongyao Wang Qinghua

应用地球化学方法进行断层的渗漏性判定是油藏地球化学近年的新进展之一。根据原油中正构烷烃的分布和生物标志物特征,柯克亚油藏存在着5种原油类型,即第一类基态原油、第二类运移分馏残余油、第三类蒸发-反凝析形成的凝析油和轻质油、第四类气洗残余原油及第五类发生晶析作用的原油。其中第二类原油主要分布在构造的顶部,说明原油沿小断层和构造顶部发生了渗漏,造成古今油水界面明显不同。原油分子地球化学分析结果也证实,在构造的顶部原油成熟度相对较高,重质组分和不易运移的组分相对较高。

It is one of the new advances in reservoir geochemistry to study leakage of fault with geochemical techniques.According to the distribution of n-alkane and the characteristics of biomarkers,there exist 5 types of crude in Kokyar oil reservoir,including original-state oil,residual oil from fractionation through migration,condensate and light oils from evaporation and retrograde condensation,residual crude from gas washing,and crude with wax crystallization.The second type of crude is mainly distributed on the top of the structure,indicating that leakage occurred along small faults and the top of the structure,leading to the obvious difference between ancient and present OWC.Moreover,molecular geochemical analysis of the crude verifies that crude on the top of the structure have relatively higher maturity and higher contents of heavy components and those uneasily to be migrated.

10.11743/ogg20040517