Sedimentary characteristics of low curvature meandering stream in lower part Minghuazhen Formation in Laibei low uplift,Bohai Bay Basin
The V oil group of the Lower part Minghuazhen Formation(N1 m1)is an essential oil-bearing horizon in Laibei low uplift,Bohai Bay basin,and the low-curvature meandering river is developed at the top of the V oil group.Based on seismic,core drilling,and logging data,the sedimentary characteristics and sedimentary model of the L sand body of the V oil group are described accurately.The main L sand body is a low-curvature meandering river,which can be further subdivided into three sedimentary microfacies:main channel,natural levee,crevasse,and flood plain.The main channel is developed with obvious positive rhythm characteristics and is stable;however,the secondary channel is limitedly developed;the lithology is mainly lithic feldspar medium-fine sandstone,with loose cementation and developed pore throat.The grain size statistics show the P-Q-R segments are primarily developed.The length of the channel of the L sand body is about 10.15 km,the length of the river valley is 8.37 km,and the bend index is 1.21.The L sand body performs a low-curvature meandering river with the width-depth ratio of the channel between 52.64 and 67.70.During the deposition period of the L sand body,the structure was relatively flat,the base level was further reduced,and the sediment supply rate was relatively low,which were the main control factors for the formation of a low-curvature meandering river.This understanding provides a reference for lithologic oil and gas reservoir explo-ration in Laibei low uplift.
Bohai Bay BasinLaibei low upliftN1m1low curvature meandering riversedimentary characteristics
NETL
NSTL
万方数据
维普
