Reservoir Prediction And Favorable Targets Evaluation In Dongying Formation In North Slope Of Chengdong

The north slope of Chengdong is located in the northeastern part of Jiyang Depression in Bohai Bay Basin.Oil and gas have been found in Dongying Formation in the study area,but the position of stratigraphic overlap lines and the reservoir development characteristics of Dongying Formation are still not clear.Previous research results in this area were scarce and have restricted the further exploration and development.Therefore,we have carried out reservoir prediction in the study area to reveal the reservoir distribution characteristics of Dongying Formation and predict favorable reservoir.In this paper,the range of stratigraphic overlap lines and the distribution characteristics of fracture system in Dongying Formation are defined by fine synthetic recording calibration,frequency dividing interpretation,AGC amplitude gain and coherence technology,variance body technique,isochronal slice technique,edge bed slice technique and so on.We have synthetically used the well-seism combination seismic attributes analytical technology and waveform indication seismic inversion technique to predict the reservoir distribution characteristics of each bed in Dongying Formation.We have confirmed the development types of sedimentary facies combined with well logging data and reservoir distribution results based on seismic phase marker identification and seismic phase analysis.Based on the above research results,including the possible oil source conditions and the combination characteristics of source-reservoir-seal in the study area,we have proposed the favorable target areas.The stratigraphic overlap lines in the study area are distributed in a circular pattern around the buried hill in Chengdong,and the sedimentary area from Ed3 to Ed1 member has gradually increased.The fault system in the study area has subarea characteristics.Chengdong fault is distributed around the buried hill in Chengdong in a semi-circular pattern,which results in great differences in stratigraphic deposition thickness between the hanging and foot wall.Deep lakes,shore shallow lakes,braided river deltas,nearshore subaqueous fans,deep-water turbidite fans and other types of phases are predominantly developed in Dongying Formation.Ed1 member is the most developed section of reservoir.Combining the conditions of oil source,the combination characteristics of source-reservoir-seal,and reservoir distribution characteristics,we have proposed two favorable target areas.