渤海湾盆地板桥凹陷沙二段滩坝沉积地层与砂体展布特征  

CHARACTERISTICS OF SEDIMENTARY STRATIGRAPHY AND SAND BODIES DISTRIBUTION OF BEACH-BAR IN THE SECOND MEMBER OF SHAHEJIE FORMATION IN BANQIAO SAG, BOHAI BAY BASIN, CHINA

作　　者：商晓飞 董越 唐力[2,3] 侯加根 SHANG Xiao Fei;DONG Yue;TANG Li;HOU Jia Gen(Petroleum Exploration&Production Research Institute,SINOPEC,Beijing 100083;China University of Petroleum,Beijing 102249;PetroChina Huabei Oilfield Company,Renqiu 062552)

机构地区：[1]中国石化石油勘探开发研究院,北京100083 [2]中国石油大学(北京),北京102249 [3]中国石油华北油田公司,河北任丘062552

出　　处：《地层学杂志》2021年第4期532-544,共13页Journal of Stratigraphy

基　　金：中国科学院战略性先导科技专项(A类)(XDA14010204)资助。

摘　　要：随着我国含油气盆地相继进入勘探开发中后期,勘探程度较低的滩坝储集层逐渐成为地质研究的热点。本文以板桥凹陷沙二段为例,基于测井、地震、岩芯等资料,利用高分辨率层序地层学原理,对滩坝沉积地层和砂体展布特征进行研究。结果表明,板桥凹陷沙二段地层为一个湖平面上升的三级层序,并可划分为湖退—湖进—湖退三个中期基准面旋回。沙二段下部表现出砂体进积的特点,物源供给速率最强,坝砂最为发育;中上部沉积物供给速率减慢,滩坝规模小,滩砂更发育。在板南地区滩坝砂体主要沉积于中期旋回的基准面下降和上升初期,滩坝随湖平面升降而迁移摆动明显,在纵向上会体现出砂岩与泥岩的规律变化。板中地区滩坝沉积明显受大张坨同沉积断层的控制,断层陡坎部位会形成持续的水动力高能环境;另一方面,同沉积断层的活动性增加了下降盘基准面上升的概率,为滩坝沉积提供了充足的可容纳空间,在纵向上体现出连续厚层滩坝堆积。在平面上,板南地区滩砂更发育,滩坝聚集带呈"条带状"平行湖盆边缘展布,平均带宽近600 m;板中地区坝砂发育,单砂体平均厚10余米,累积厚度可达近100m,主要"依附"大张坨断层下降盘展布。本文结合不同构造部位滩坝砂体的分布特征,明晰了板桥凹陷滩坝储层具有"远源断控"和"近源相控"两种油气成藏模式,并指明了下一步勘探开发目标的有利区。As the exploration of petroliferous basin entering into the middle and later stage, the less explored reservoirs in beach-bar are the most important target of oil and gas exploration in recent years. The sedimentary characteristics of beach-bar reservoirs of Es2 in Banqiao Sag were studied using the seismic, logging and core data.The stratigraphic units were divided based on high-resolution sequence stratigraphy principle, and beach-bar sand body distribution and its controls were analyzed in time stratigraphic units. Results indicate that, the 2;Member of Shahejie Formation is a third-order sequence of lake level elevation, and can be divided into three medium-term base-level cycles: Lake regression-lake transgression-lake regression. The lower part of Es;shows the characteristics of sand body prograding, which results in the strongest material source supply rate and the most developed bar sand. In the middle and upper part of Es;, the sediment supply rate slows down, and the scale of beach bar decreases, showing the beach sand is more developed. The beach-bars in the south of Banqiao Sag are mainly deposited at the descending and early rising stages of the medium-term base level cycle, and migrate and oscillate obviously with the rise and fall of the lake plane, which reflects the regular change of sandstone and mudstone in the longitudinal direction. Whereas, the beach-bar sediments in the middle of Banqiao Sag are obviously within the controlling of contemporaneous fault. The fault fractured surface is of persistently high hydrodynamic energy, on the other hand, the activity of the contemporaneous fault adds the possibility of the base level rising in the downthrown wall and provides enough accommodate for the beach-bar sediments, which reflects continuous thick layer accumulation in vertical. The beach-bar sand bodies are mainly deposited at the descending and early rising stages of the medium-term base level cycle. The beach sand bodies are more developed in the south area, and the bar sand bodies are strip

关 键 词：滩坝 层序地层 砂体分布 同沉积断层 板桥凹陷 沙河街组二段 

分 类 号：P548[天文地球—构造地质学] P618[天文地球—地质学]