坪北地区长6油层组高分辨率层序分析与等时对比
High Resolution Sequence Analysis and Isochronalstrati-graphic Correlation of Chang 6 Oil Reservoir Set in Pingbei Area
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摘要: 以高分辨率层序地层学理论体系为指导思想,通过基准面旋回结构和叠加样式的沉积动力学分析,采用多级次基准面旋回划分方案,研究陕北坪北地区上三叠统长6油层组高分辨率层序地层学特征,通过钻井岩心与测井资料的综合分析,从该油层组中识别出三个级别的基准面旋回界面,以界面的成因和级别为依据,将长6油层组划分为短期、中期、长期三个级次的旋回层序。根据多级次旋回层序划分结果,运用旋回等时对比法则对各级次旋回层序进行等时对比并建立不同尺度的时间-地层格架,讨论了不同时间尺度的层序地层格架在油气勘探开发各阶段的研究意义。Abstract: Based on the theoretical system of high resolution sequence stratigraphy, this paper studies the high resolution sequence stratigraphic characteristics of the Chang 6 oil reservoir set of the Upper Triassic in Pingbei area through sedimentary dynamic analysis of cyclic structure and overlapping pattern of the base - level and by using multi -grade base - level cycle dividing scheme. Base - level cyclic interfaces in three grades are identified from this oil reservoir set through comprehensive analysis of core and logging data. The Chang 6 oil reservoir set is divided into short term, medium term and long term cyclic sequences according to the genesis and grade of the interfaces. I-sochronal correlation is performed on the cyclic sequences of each grade by using cyclic isochronal correlation principles and on the basis of cyclic sequence division, and time - stratigraphy frameworks of different scales are established. The significance of sequence stratigraphy frameworks with different time scales in petroleum exploration and production is discussed.