辽河西部凹陷滩海地区复合含油气系统中的油气运移流向探讨

油气运移流向研究有助于认识含油气系统内部的油气运聚与油气分布规律。利用地震、测井和地质资料对辽河西部凹陷滩海地区含油气系统中的油气运移流向进行了研究，分析了区内现今异常压力的分布规律，并用逐层回剥的方法恢复了Es3＋4和Es1＋2的流体势。研究结果表明，异常高压和流体势的展布规律显示了油气主要沿着几个优势运移通道运移，笔架岭-西部斜坡带、双台子和中央低凸起等构造带是油气运聚的有利部位，其中以向中央低凸起上的运移优势最为显著。研究区主要存在断裂带、横向连通的储集体和区域不整合面3类输导层，这3种输导层往往相互配合完成对油气的输导。油气输导层与优势油气运移通道往往形成统一的油气输导体系，极大地促进了油气输导的效率。油气勘探成果证明，研究区内油气运移的主要流向与有利油气赋存单元的分布相吻合，主要含油气单元围绕海南生烃中心成环带状分布，有利于指导后期油气勘探和勘探目标的优选。

Study on pathways of hydrocarbon migration of composite petroleum system in Tanhai area, western of Liaohe depression

The dominant pathways of hydrocarbon migration often play critical roles in hydrocarbon migration, accumulation and distribution of petroleum system. By making full use of seismic data, log data and geologic information, fluid pressure and fluid potential of three source rocks were calculated to determine the domninant pathways of hydrocarbon migration in Tanhai area, western of Liaohe depression. The distribution and characteristics of abnormal overpressure and fluid potential suggest that the dominant directions of hydrocarbon migration in the study area are consistent with potential petroliferous units. The Bijialing, west slope, Shuangtaizi and central horseback are the advantageous structural belts for hydrocarbon accumulation, and the central horseback is the most effective unit for hydrocarbon migration. Unconformities, sandstone-conglomerate bodies and faults are the main links between source rocks and oil and gas Fools, they match with each other and act as the cartier beds of oil and gas. Especially, the carrier beds and advantageous directions of hydrocarbon migration always make up of a carrier system, and play an important role in hydrocarbon migration and accumulation. As demonstrated by petroleum exploration, the centers of main source rocks in Hainan sag were circled by nine potential petroliferous units, which had significance in exploration target evaluation and hydrocarbon-bearing units optimized for future exploration.