鄂尔多斯盆地宜川地区延长组层序地层研究

目的对宜川地区延长组层序进行详细划分,论述层序演化特征,并分析层序对油气藏的控制作用。方法在对露头剖面、钻井岩心及测井曲线综合分析的基础上,结合层序界面识别、准层序样式及演化、层序的划分和对比、沉积体系域识别及其组合样式,对地层进行划分。结果该地层自下而上为S1,S2,S3和S4;S1至S4分别经历了湖盆形成及扩张期、鼎盛期、回返期、萎缩消亡期。结论研究区的层序对于生储盖的组合、储层的展布以及储层的储集性能均有一定的控制作用;研究区有利储集层为长8和长6油层组。

Sequence stratigraphy of triassic Yanchang Formation in the area of Yichuan

Aim To carefully study sequences of the Upper Trissic Yanchang Formation,analyse the characteristic of sequences environment and study the control function between the sequences and oil reservoir in the area of Yichuan.Methods On the base of comprehensive analysing outcrop section,well core and well-logging date,the characteristics of different sequences and its evolvement are analyzed according to the characteristics of sequence boundarys,the patterns of parasequence,the partition and contrast of the Yanchang Formation sequences.Results The strata of Yanchang Formation in the area of Yichuan have been divided into S1,S2,S3 and S4.From S1 to S4,Ordos basin develops from initially forming,expanding,most prosperously dominating,contracting to vanishing.Conclusion The sequences in studying area control the combination of oil-generating strata,reservoir and cover rock,the distributing of reservoir and the capability of reservoir.Based on the characteristics of different sequences evolvement,advantageous reservoirs lie in Chang 8 and Chang 6 in the area of Yichuan.