东濮凹陷黄河南地区下第三系沉积体系与油气评价

为了加速东濮凹陷黄河南地区油气勘探的步伐,本文根据现代沉积体系理论,综合运用地质、测井和地震资料,首次在东濮凹陷黄河南地区下第三系中系统地确定了冲积扇、河流、扇三角洲、三角洲—滑塌浊积扇、滩坝、近岸水下扇和轴向重力流水道等7种类型的沉积体系,并描述了这些沉积体系在地质、测井和地震等方面的沉积特征。结合盆地断裂活动特点,指出充填盆地沉积体系的演化具有明显的阶段性,沉积体系的平面展布具有不对称性,从而建立盆地沉积体系演化模式。同时,结合油气勘探实践指出富集油气的有利相带。

PALEOGENE DEPOSITIONAL SYSTEMS AND OIL-GAS EVALUATION IN AREAS SOUTH OF THE YELLOW RIVER IN THE DONGPU DEPRESSION

Seven dopositional systems, i.e. the alluvial fan, fluvial,complex delta,beachbar,fan-delta, nearshore subaqueous fan and axial gravity flow channel systems, havebeen recognized in the Paleogene,of the Dongpu depression by means of integrat-ing the geologica, logging, seismic and laboratary data. These depositional systemswere controlled not only by the tectonic activities but also by the paleogeograph-ic settings such as paleotopography, paleoclimate, paleobathymetry and paleosa-linity. Furthermore, the sedimentary settings, petrological, mineralogical and paleo-ntological features,log-probability curves, C. M diagrams, SP curves, seismic reflec-tion features, shapes and distribution of sandbody and sedimentary structure ofthe 7 typas of the depositional systems are introduced. It is pointed out that thestudy area is characterized by complex Paleogene source rocks, stable drainagesystems, obvious fluvial and gravity flow actions. asymmetric distribution of thedepositional systems in plan and inherited vertical evolution of the depositionalsystems. This paper finally summarizes the relation of the fan-delta and axialgravity flow channel sandbody and oil-gas accumulation and points out the direc-tion in petroleum exploration in the futuro.