Characteristics Of Depositional Filling And Sandbody Spreading And Reservoir In Shahejie-dongying Fm Of Fulin Sag Of Shengli Oilfield

Fulin sag is a secondary tectonic unit in zhanhua depression of jiyang depression in bohai bay basin.On the basis of predecessors,the paper is guided by sedimentary geology,well logging geology,lithofacies paleogeography and geophysical theories.Well Logging,mud logging and seismic inversion data are used to study the Characteristics of depositional filling and Sandbody Spreading and Reservoir in the area.The achievements and understanding have been achieved as follow:1.Based on the study of geological background of Fulin sag area,the regional stratigraphic framework of drilling combining the stratigraphic section is established by well-seismic calibrate.On the basis of single well stratigraphic subdivision,well seismic calibration and well-connected stratigraphic correlation,we have prepared the Spreading and Reservoir maps of fracture system of each group and the stratigraphic thickness correlation maps of each group,we studied the stratigraphic plane distribution rules in each stratum,the three direction fracture which are NNE,NEE and NW fractures are identified generally.The fault structures in all directions are obviously different,and their controlling effects on the depositional sand body are also very different.The fulin sag is divided into three sub-depressions e.g.west,middle and east from west to east:.The Shahejie Fm-Dongying Fm are divided into 5sequence interfaces.2.On the basis of outcrop and core observation,mug logging and well logging data analysis,the study on identification marks of Paleogene System sedimentary facies in fulin sag is carried out,which mainly includes: primary sedimentary structural marks,well logging facies marks,seismic facies marks and petrological marks.3.On the basis of sedimentary facies identification mark,single well sedimentary facies map was drawn,and the study on sedimentary facies division was carried out.4 types of sedimentary facies are identified which are braided river delta,fan delta,lake and nearshore subaqueous fan deposit.Braided river delta facies were mainly developed in third member of Shahejie Fm;fan delta facies were mainly developed in forth member of Shahejie Fm;lake facies were developed in every member of Shahejie Fm;nearshore subaqueous fan deposit facies were developed in lower third sub-member and middle third sub-member of Shahejie Fm;Based on above,the well sedimentary facies maps and sedimentary facies map of each memberare drawn.4.Based on the study of the sedimentary background in the fulin sag area and combined with the seismic inversion data,two types of provenance channels have been identified,including the palaeo-channels and aulacogenes-channels.The ancient landforms of each period were restored,and the slope belt was divided into three types from west to east,including the fault steep slope break zone,the landforms gentle slope break,and the consequent fault gentle slope break.By using well logging and seismic inversion data,the sand body plane Spreading and Reservoir map and root-mean-square attribute map of each member were drawn,and the sand control model of Dongying Fm and Shahejie Fm was established.5.Based on the above depositional filling and Sandbody Spreading and Reservoir characteristics,the Dongying Fm-Shahejie Fm delta-lake sedimentary model in fulin sag area was established.