Study On Sequence Stratigraphic Framework And Sedimentary Microfacies Of Shallow Water Delta In Depression Area

Based on the theory of high-resolution sequence stratigraphy and continental sedimentology,this paper makes full use of core,logging,drilling and 3D seismic data to explore the high-precision The stratigraphic framework and the sedimentary facies model of the high frequency(Five-level sequence)of the Fuyu reservoir in the study area were established,which laid a foundation for the prediction and accumulation of sand bodies in the area.Solid geological foundation,the project has made the following research results:A total of 13 sequences interfaces are identified in the Fuyu reservoir of the Quantou Formation in the Gulong depression,including three cascade interfaces,three cascade interfaces,and seven cascade interfaces.It is divided into four types: sedimentary unconformity,lake flood face(Initial lake flood face and maximum lake face),water intrusion sequence and additive type sequence interface.According to the different properties of the sequence interface,the internal configuration and the distribution characteristics of the sedimentary facies sequence,the Fuyu reservoir in the Guolong Depression can be divided into two types of system tracts,namely,the sequences SQ?1-q4 controlled by the sequence interfaces SB2 and SB21 are(TST),the sequence SQ?1-q3 controlled by the sequence interfaces SB21 and SB22 are the low water level system domain(LST).Under the constraint of the four-level sequence lattice,the principle of "cycle comparison,grading control,different phases are treated differently" is combined with the core logging data of 20 exploration wells and the 7 horizontal-SQ?1-q3,SQ?1-q4 Fuyu Oil Layer Yingtai-New Station Area 5 Sequence Stratigraphic Framework.Based on the detailed observation and description of the core,comprehensive utilization,logging,logging,earthquake and analysis and verification data,the classification criterion of sedimentary microfacies was established.Based on the characteristics of vertical sedimentation cycle,and the sedimentary facies of sedimentary facies and the sedimentary facies are reconstructed,and the evolution history of Fuyu reservoir is restored.The control of sedimentary facies and the control of sedimentary facies and sand bodies at all levels of sequence boundaries.The study shows that SQ?1-q3 deposition period is in the depositional decline period,and small shallow lakes are sporadic in the background of river facies deposition.The sediments are mainly composed of fluvial facies and shallow water delta facies.In the SQ?1-q4 depositional period,with the increasing deposition base,the lake area gradually increased,and the sedimentary environment was converted to the delta and lake facies.In the late SQ?1-q4,the semi-deep lake-deep lake facies,lake fan deposition and turbidite sedimentary development began to appear.The sand body is gradually thinned with the ascending sand body of the deposition datum,and the sand body type is also from the river of the river,the meandering river to the reticular river and the shallow water delta.The delta is evolved,feature.Yingtai-New station area mainly developed underwater distributary channel,diversion channel,point dam,and seat sand four types of reservoirs.Based on the seismic sedimentology method,the sedimentary system distribution and sand body prediction are studied by means of seismic attribute analysis,seismic waveform difference inversion and seismic waveform difference simulation inversion.Geological body seismic identification template is established.In the sequence stratigraphic framework,the sand bodies are the meandering channel sand bodies,the shallow delta plains diversion channel and the delta front submarine distributary channel sand bodies,and the distributary distributary channel sand bodies are distributed in the south-south direction,forming the main part of the Fuyu oil layer of the reservoir sand body.Through the reservoir analysis,quasi-sequence stratigraphy,sedimentary facies distribution is the main controlling factor in the study area.In general,the types and distributions of sedimentary facies and sand bodies,sedimentary facies and sand body types in sequence stratigraphy control the types of traps,traps and fracture development and tectonic setting,which control the reservoir type and Reservoir pattern.The reservoir formation patterns of five types of reservoirs are established,in order to find different types of oil and gas reservoir clear direction.