泥岩涂抹定量研究

Quantitative study of shale smear

对泥岩涂抹现象、断层封闭机理及控制因素进行了研究,探讨了泥岩涂抹定量计算及其存在的问题。研究结果表明,泥岩涂抹量主要取决于断层的断距、岩性组合及泥岩塑性等多种因素。泥岩涂抹量的计算应以构造发育史、压实史研究为基础,定位出断层首次活动的时期、地层埋深及被断岩层的流变性,这样才能确定其是否发生过泥岩涂抹,然后再进行计算。对营32 断层的泥岩涂抹研究表明,该断层南段几个重要含油层位的封闭性不好,导致油气穿越断层,发生了油气再运移;而北段所有含油层位都是封闭的。这说明同一条断层的封闭性存在着差异并且发生动态性变化。

The quantitative calculation of shale smear and some unresolved problems were researched based on the phenomenon of shale smear, fault sealing mechanisms and its controlled factors. The shale smear was controlled by fault throw, lithologic association and shale plasticity. According to structural history and compaction history, the first active period of fault, buried depth of formation and faulted formation plasticity can be determined. Furthermore, the shale smear may be counted if shale smear occurred. The study of shale smear shows that hydrocarbon remigration happened along a few layers in south fault of Ying 32, because the sealing property of a few important layers was poor, which made hydrocarbon migrate across the fault, while all oil-bearing layers were sealed in the north fault of Ying 32. All those indicated the difference of sealing properties and dynamic state for the same fault.