Sedimentary Model and Evolution Law of Meandering Rivers:A case study from the lower Minghuazhen Formation of L oilfield in Bohai Bay Basin
[Objective]There are many meandering river depositional models in the lower Minghuazhen Formation in L oilfield.Their sedimentary models and evolutionary laws are not yet clear.[Methods]The meandering river characteristics and their paleogeological background in different periods are systematically analyzed by using paleo-ntological,core,sidewall core,well logging data,and seismic data.Then,the evolution law is summarized.[Results]The study shows that during the sedimentary period of the lower Minghuazhen Formation,there are 5 types of meandering rivers developing successively in the study area.The river type of the L44 sublayer is a braided-meandering symbiotic model.The river type of the L24-L04 sublayer is a high-curvature meandering river.The river type of the L23 sublayer is a restricted high-curvature meandering river.The river type of the L03 sublayer is a string-beads meandering river.The river type of the L2 oil group is a low-curvature meandering river under lake-level.[Conclusions]During the sedimentary period of the lower Minghuazhen Formation,the paleogeological background of the studied area also evolved continuously.Because of the coupling effect of different paleogeological factors,such as sedimentary base level cycles,paleoclimate,paleogeomorphology,and the water environment in sedimentary area,various types of meandering rivers were formed in the different periods.
low-curvature meandering river under lake-levelrestricted meandering riverhigh curvature meandering riverbeaded meandering riverbraided-meandering symbiotic river
国家科技期刊平台
NSTL
万方数据
