东营凹陷大芦湖油田东北部沙三中亚段沉积体系演化

The Sedimentary System Evolution of the Middle Member of Es_3 in the Northeast of Daluhu Oilfield of Dongying Depression

综合利用钻井岩心、地震、测井、录井及各种分析化验资料,建立了大芦湖油田东北部沙河街组三段中亚段高精度层序地层格架,明确了沉积体系类型及垂向演化规律。研究区可划分为3个四级层序,自下而上分别为四级层序1、四级层序2和四级层序3。研究区主要发育三角洲、浊积岩和滨浅湖滩坝沉积:三角洲是研究区主要的沉积相类型,在3个四级层序均有发育;受断层坡折和负地形的影响,浊积岩主要发育在四级层序1和四级层序2早期,位于三角洲沉积前端;滨浅湖滩坝沉积主要发育在四级层序2晚期和四级层序3时期,受相对平缓的古地貌、滨浅湖波浪和沿岸流作用的影响,该沉积是由三角洲前缘沉积物被再搬运、沉积而形成。总体而言,相对湖平面的变化规律和沉积古地形的演化特征控制了研究区垂向上的沉积体系演化规律。

By using the date of drilling cores,seism,well logging and geologic logs,a high precision sequence stratigraphy framework of the middle member of Es3 in the northeast of Daluhu Oilfield was established.The type of sedimentary system and the vertical evolution law were clarified.The research region was divided into 3fourth order sequences.From the bottom to top,it was Sequence 1,2,and 3.The delta,turbidity and shallow lake-beach bar sediments were developed in the research area.Among these facies,the delta sediment was the major one.And it was developed in all the three of fourth order sequences.The turbidity sediment was controlled by the fault slope break and negative relief.It was developed in the early Fourth Order Sequences 1and 2and it was in the front of delta sediment.The shallow lake-beach bar sediment was controlled by alongshore current and waves formed from the delta front sediment that was transported and deposited to the deep water.It was developed in the late period of Fourth Order Sequences 2and 3.The vertical evolution rules of the sedimentary system in the studied area are controlled by the relative lake level change and the characteristics of sedimentary palaeotopography evolution.