Sedimentation environment reconstruction of Bathonian and Cretaceous sediments using seismic data interpretation and well logging analysis (on the example of the Geophysical field, Gydan Peninsula)

Abstract

Based on the analysis of seismic attributes, the shape of the SP curves, lithological and petrophysical data, and well test results, the sedimentation environments of the Bajocian, Berriasian-Hauterivian, Aptian and Cenomanian sandstone beds of the Geophysical field were reconstructed; its facies and zones of sandstone beds distribution and its claying are determined. According to the results of the research for reservoir J 2-4 (Bajocian) latitudinally oriented paleoflows and orthogonal to them zones of sandstone bodies associated with alongshore terrigenous material transfer were contoured during periods of hydrodynamic activation of the aquatic environment. For sandstone bed BG 16 of the Akhskaya Formation: facies of alluvial cones, area of temporary flows discharge, offshore regressive bars and shore banks were identified. It was considered that the sandstone bed BG16 was formed in an environment of shore sedimentation systems moving towards the sea basin. The sandstone beds TP 23-26 of the Tanopchinskaya Formation were classified as to sandstones of river channels and channel banks of meandering rivers. It is concluded that the TP 2-3 sandstone beds in the upper part of the Tanopchinskaya Formation are correspond to facies of riverbeds and flow of discontinuous flows. In the upper part of the Cenomanian sandstone horizon PK 1 , several transgressive cyclites were distinguished, the formation of which occurred in marginal-marine conditions; in the lower part of the horizon, where sediment formation was under paleodelt conditions, sandy bodies along the coast are predicted.