| This paper takes Chao94 development block of Chaoyanggou anticline in Songliao Basin as the research target area.In view of the poor reservoir utilization of the Yangdachengzi oil formation in the study area,it is urgent to deepen the understanding of the distribution characteristics of sand bodies in the study area with the opportunity of drilling and infusing32 new Wells this year.Guided by seismic sedimentology,oil and gas field development geology,sedimentary petrology and other theories,this paper adopts the method of combining well vibration to make full use of the advantages of vertical and horizontal high-resolution well vibration data.The purpose is to improve the prediction accuracy of continental meandering river reservoir in Chao94 Development Zone,and to describe sedimentary microfacies in detail,so as to guide the optimization and adjustment of well pattern injection-production relationship in the later period of the oilfield,and achieve the goal of stable production and increased storage,and obtain the following understanding:(1)Guided by the principle of seismic sedimentology and based on the depositional cycle,lithology association and strata contact relationship of newly drilled closed core well,the "closed skeleton profile control correlation" method is adopted to conduct the target horizon system stratification in the whole area under the constraint of top and bottom marker and reference layer and combined with seismic reflection characteristics.The two confirm each other.A fine isochronous stratigraphic framework of 22 small layers and 47 sedimentary time units was established in the whole area,and the thickness of each unit layer was moderate except for the main layer.(2)Based on 3D seismic data,combined with reservoir development characteristics in the study area,based on the principle of first qualitative and then quantitative,slice optimization of seismic attributes is carried out.Single reservoir sensitive attributes,RGB multiattribute fusion,and 4D spectral decomposition techniques are adopted to provide technical basis for the joint well seismic characterization of sand bodies of different channel sizes.The preferred waveform indication inversion uses the transverse change of seismic waveform to reveal the characteristics of the phase transition of the reservoir spatial structure.By optimizing the key inversion parameters,the reservoir prediction results can be guaranteed to have a higher resolution.After the post-well test,the inverse anastomosis rate of sandstone with thickness above 3m is more than 83.3%.(3)Taking the opportunity of newly completed sealed coring wells in the research area,based on detailed observation and description of rock cores,a total of 1 facies-fluvial facies,4 subfacies-riverbed,embankment,riverbank,and oxbow lake were identified in the research area,and 6 microfacies-main river channel,non main river channel,abandoned river channel,main overflow bank sand,overflow bank sand,and flood plain.The logging curves were optimized,and the logging facies model was established through the correspondence between rock and electricity.(4)Using the method of "Seismic attribute finalization,seismic inversion delimitation,and well point phasing" to describe the sedimentary microfacies,we focus on the fine description and identification of the internal single stage river channel boundary of the composite sand body.Based on the combination of well and seismic,we have completed the fine description of the sedimentary microfacies map of each sedimentary time unit of Yang I oil formation and Yang II oil formation,Research shows that the Yangdachengzi sand body in the research area is mainly developed by narrow and small river channels(width<300m)with thin layer sand bodies(thickness<3m),among which various types of river channel sand bodies are mostly distributed in a southwest northeast direction,and the overall reservoir development is poor. |
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