渤海湾盆地东濮凹陷T-R旋回层序地层学与隐蔽油藏研究

作者从经典模式应用于断陷盆地中所存在的问题讨论入手,认为T-R旋回划分方案更适合中国东部陆相断陷湖盆的层序地层学研究.同时,还运用T-R旋回的基本概念与原理,分析了断陷盆地层序地层学T-R旋回的层序地层格架模式,建立了东濮凹陷下第三系三级层序地层格架,将下第三系划分为1个一级T-R旋回、3个二级T-R旋回,并进一步从沙河街组中识别出9个三级T-R旋回.通过研究主要目的层三级层序湖进(T)和湖退(R)体系域的沉积体系展布,进一步查明主要目的层段的砂体分布规律,确立有利于隐蔽油气藏发育的砂体类型,并预测其有利勘探方向.

STUDY ON THE SEQUENCE STRATIGRAPHY OF T-R CYCLES AND SUBTLE OIL POOLS IN THE DONGPU DEPRESSION

Aimed at the discussion of problems existing in the application of the classical pattern to fault basins, the authors considered that the T-R cyclic division scheme was more suitable to the sequence stratigraphic research of continental lake basins in the eastern part of China. By using basic T-R cyclic concepts and principles in the meantime, the authors also analysed the sequence stratigraphic framework pattern of T-R cycles in fault basins, and established three-grade sequence stratigraphic frameworks in the Lower Tertiary of the Dongpu Depression. The Lower Tertiary was divided into one first-grade T-R cycle and three second-grade T-R cycles. And nine third-grade T-R cycles were further distinguished from the Shahejie Formation. Based on the study of the sedimentary system spread of transgressive(T)and regressive(R)system tracts in the three-grade sequences of major target strata, the distribution rules of sandbodies in major target strata were examined, the sandbody types advantageous to the development of subtle oil and gas pools were determined, and the favorable exploration direction was predicted.