Research Of Sedimentary Systems And Prediction Of Favorable Reservoir Facies Of The Third Dongying Formation In The South Of Liaoxi Low Uplift

Liaoxi low uplift divided Liaoxi sag from Liaozhong sag. The Paleogene System of Dongying formation can be divided into three third-order sequences and six fourth-order sequences. The third-order sequences can be divided into three fourth-order sequences by secondary-order water flood surface, they are up Dongsan, middle Dongsan and low Dongsan..Theories and Methods of Applied sedimentology , sequence stratigraphy,structural geology and basin analysis are used in this study. Seismic, logging, and core materials are also comprehensively applied in basin tectonic and basin fill analysis to establish basin filling sequence stratigraphic series and isochronous stratigraphic sequence contrast framework, and to study sedimentary facies and their various distribution pattern in stratigraphic framework, and to reveal the influence of stratigraphic architecture and basin fill pattern to basin structure and evolution of lake provenance systems, in order to establish basin fill pattern and composition of reservoir and seal rock pattern.Every sequence can be divided into LST, TST, HST and FST by IFS and MFS. Normal water back deposition can be found in HST, which characterized by progradation with high angle, Prograding rate of normal lake back system was growing while vertical accretion rate decreasing, and they always developed to FST.There are four main tyes sand distributed systems. The fan delta or braided delta system, steep-nearly and sublacustrine fans gentle slope-nearby, Littoral and shallow lake - beach dam system deep lake , mud system. Steep slope of basin has devoped fan delta system while gentle slope developed braided delta, and lake face developed in other part of basin.The majority provenance was from the west during transgressive period , gentle slope belt along the shorter axis direction of basin developed braided delta and regressive depositional system landward, while sand beach dam devoleped in the uplift; provenance was from the west slope during the regressive period, braid delta prograded and expanded lakeward, while semi-deep lake system shrinked .It is found that the lake level change, climate, and provenance supply are governing factors of sequence and sedimentary system development , and the south of Jinxian area is favourable trap .