High Resolution Sequence Stratigraphic Technique for Detailed Correlation of the Fluvial Deposits

The area of study is located in the Yamal Peninsula. The main accumulations are within terrigenous deposits of Cenomanian-Albian and Aptian-Barremian-Hauterivian ages of the Upper and Lower Cretaceous with sedimentary environments ranging from shallow marine to continental. The uppermost part of the Aptian-Hauterivian member are the most proximal deposits of the second order Apto-Albian regressive-transgressive cycle. They correspond to delta plain to distal fluvial setting, where high resolution sequence stratigraphic interpretation is impeded by the lack of laterally extensive marine maximum floodings and of clear-cut transgressive wave ravinement surfaces. Therefore an adapted methodology had to be used, based on the concept that the dominant depositional process is aggradation, with a slight progradational component in the fluvial.A critical part of the methodology is to ensure continuously the 3D coherency in order to avoid the cross-correlation. The correlations allowed distinguishing two types of reservoir units -incised valleys and amalgamated channel belts - and their architecture at a detailed scale which is known to be critical for reservoir management and field development strategy.