贝尔凹陷关键层序识别与油气意义

Characteristics and Hydrocarbon Significances of Key Sequences in Bei'er Sag

在充分消化、吸收贝尔凹陷现存多套地层划分对比方案基础上,综合参考岩性特征、电性特征、三维地震界面特征及孢粉组合特征,从建立贝尔-南贝尔-塔南凹陷层序格架出发,将贝尔凹陷铜钵庙-南屯组划分为4个三级层序。其中该次识别的关键层序——SQn41沉积时期构造运动相对平静,主要发育扇三角洲、湖泊及湖底扇等沉积类型,在海塔盆地具有良好的对比性。SQn41层序的发现使得建立海塔盆地等时区域地层格架成为可能。

On the basis of research of many sets of available stratigraphic division planes,the lithologic,electric logging,and 3Dseismic interfacial and sporopollen assemblage characters were integrally studied.The sequence framework was established for Bei'er-Beinan-Tanan Sag.Based on previous stratigraphic classification and correlation,it was proposed that Tongbomiao-Nantun Formation in Bei'er Sag was divided into 4third-order sequences.SQn 4 1 was the key sequence recognized in this paper,and it was formed without intense tectonic movement.Fan delta,lacustrine,and sublacustrine fan deposits were mainly developed in the sequence.The characteristics of these depositional systems can be correlated well within Haita Basin.The reorganization of SQn 4 1 enables the establishment of sequence stratigraphic framework in Haita Basin and it further requires a new classification of sediment and reservoir units.