E. A. Badalyan, I. G. Chernova, A. S. Egorov

Sedimentation model of the Middle Jurassic Tyumen Formation layer U2-1 (Yamalo-Nenets Autonomous Okrug), based on the comprehensive analysis of geological and geophysical data

Abstract. The example of an oil and gas condensate field in the northern part of the West Siberian oil and gas basin in the Yamalo-Nenets Autonomous Okrug demonstrates how applicable the regional data are for sedimentation process awareness in the region to study and how important it is to delve into all multi-level data to build a reliable 3D geological model basis. The comprehensive analysis of heterogeneous geological and geophysical data resulted in developing a sedimentation model of the Upper Tyumen Formation layer. Tidal plain conditions in the littoral zone in areas with predominant clay and mixed sandy-clay sedimentation formed the Middle Jurassic layer in the study area. The bulk of sand bodies are confined to point bars formed as a result of lateral accretion. Mudded channels limit the bar bodies. The qualitatively interpreted seismic data led to identify the layer facies features corresponding to the electrofacies analysis data and core facies. The obtained data confirm the prognostic value of the sedimentation model to be used as a reliable basis for a future 3D geological model.

Keywords: conceptual model, facies analysis, sedimentation description, electrofacies, seismic data interpretation, seismic facies, spectral decomposition, West Siberian oil and gas basin