摘要:
不同体系域砂体分布和成藏特征存在明显的差别,正确划分体系域对于油气勘探,特别是隐蔽油气藏勘探具有重要意义。相对于海相地层,由于陆相层序本身的复杂性,并不发育明显的坡折带,在进行体系域划分时,不同学者有不同的划分方案,无论在井上还是地震上很难把握各体系域界面的位置。针对这个问题,结合渤海海域沙垒田凸起东南部东二段体系域划分,提出利用多种不同尺度资料层层控制来划分低位域、湖泛域和高位域的思路方法。这种从尺度较大资料到较小尺度资料层层控制来划分体系域的思路方法,可以避免直接从井上来进行划分导致的错误结论,同时相对湖平面变化曲线法的引用,向建立渤海东营组层序划分的标准迈向了坚实一步。
Abstract:
There are significant differences in the sandstone distribution and oil-gas accumulation character in different system tract. The correct division of system tract is of significance for petroleum exploration, particularly exploration of subtle traps. Comparing to marine strata, the division of continental sequence system tracts is difficult because due to its complexity. Different scholars advocate different division schemes, and we are difficult to make sure the position of system tract boundaries. Taking the division of the system tracts for the second Member of the Dongying Formation in the southeast of Shaleitian uplift of the Bohai area, this paper puts forward the method using variety of geological data on different scales to distinguish lowstand system tracts, transgressive system tracts and highstand system tracts from each other. This method can help us escaping from the mistakes often encountered in the analysis of well data directly and better use the relative lake-level change curve, as a solid step to establish the standard of sequence division for Dongying Formation. As the depositional characteristics, types of traps and reservoir characteristics are quite different in different systems tract, the correct division of the system tract is significance for the hydrocarbon exploration.
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