Research On Sedimentary Facies And Reservoir Architecture Of Neogene In Yangerzhuang Oilfield

The study area is a fluvial deposits oilfield with a combined watercut of more than 95%.It has entered the stage of high watercut.with increasingly contradictions in oilfield development.The previous research results cannot meet the current needs of oil production and development.It's urgently needed sedimentary research and reservoir architecture research.Based on the core,logging data,and seismic data,this paper builds a sedimentary facies model according to isochronal stratigraphic comparison studies.The study of reservoir architecture was carried out according to the principle of "level analysis,model fitting",and the influence to remaining oil was also discussed.This paper obtained the following research results through research.(1)Confirm the types of sedimentary facies in study area,The Guantao Formation is braided river sediments which developed micro-facies such as channel bar,braided river channel,channel lag deposits and crevasse splay;the Minghuazhen Formation is meandering river deposits,and it developed point bar,channel lag deposits,abandoned channel,levee,and crevasse splay.(2)Established the classification scheme of meandering river and braded river,this paper focus on the research of 7~9 level of reservoir architecture,single river channel is belong to 7th architecture unit,the corresponding interface is the 7th architecture interface;the 8th architecture unit in study is point bar and channel bar.The internal unit in point bar and channel bar is belong to 9th architecture unit.(3)The research results show that the length of point bar in Minghuazhen Formation is 246-2630 m,the width is 136-1897 m,and the length of channel bar in Guantao Formation is 529-1876 m,and the width is 180-482 m.There are 3-4 stages of vertical deposits in one channel bar.(4)In the study area,the superposition of the river channel and the pinch-out of sand bodies form the remaining oil enrichment;the rhythm of the sand bodies and the obstruction of the abandoned channel affect Water injection cause the remaining oil enrichment;the internal architecture of point bar and channel bar will also affect the remaining oil distribution.