Seismic Sedimentology in Multiple Sources-Complex Depositional Systems of Chepaizi Uplift,Junggar Basin
Fan Xiaoyi
Yao Guangqing
Yang Zhenfeng
Xiao Xue
Yue Xinxin
Abstract：The Neogene Shawan Formation from the Chepaizi uplift of the Junggar basin,has multiple sources and complex depositional systems.It has long been debated about the depositional systems due to limited well and core data.Besides,it is hard to depict the spatial and temporal evolution.The depositional system is the key to depict the single sandbody and its archi-tecture,which has a profound meaning for hydrocarbon exploration.Based on 3D seismic data,core data and well logs,com-bined with the seismic geomorphology approach,the depositional systems and evolution history of the Neogene Shawan Forma-tion in the Chepaizi uplift of the Junggar Basin were studied in great detail.A sequence stratigraphy framework was established. And,two third-order sequences,namely,sequences NSQ1 and NSQ2 from base to top,and four forth-order sequences were identified from the Shawan Formation.Six depositional systems,namely,braided river,alluvial fan,meandering river,mean-dering river delta,fan delta and shallow lacustrine systems,were identified.Then,two sedimentary models,namely,alluvial fan-braided river systems and fan delta-meandering river delta systems,were built in the study area.Finally,the prediction model of sand bodies was constructed.There has showed significant indication of oil and gas in the sand bodies of braided riv-ers,mid-channel bars,point bars,and alluvial fan.So,they are the primary reservoirs in study area.It is proved that seismic sedimentary is a useful approach applied in multiple sources,complex sedimentary systems in gentle slope of lacustrine basin when core data and well data are limited.
Keywords：multiple sources-complex depositional systemsseismic sedimentologysedimentary evolutionShawan FormationChepaizi uplift
Publication Date：2018-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：16( 786-801 )