Facies Analysis and Reservoir Properties of Early Cretaceous Beds in Samotlor Field, West Siberia Basin

Samotlor-Rubinovaya Square is an area of the western part of the Samotlor field - one of the biggest fields in the West Siberia basin. The Early Cretaceous sediments (Alym Suite) have the greatest potential to contain residual reserves. But the maximum part of it is already extracted from this formation and to maintain additional reserves were made estimation of reservoir quality using petrophysical data from wells and petroelastical data from seismic by seismic attribute analysis, facies analysis based on core analysis. Analysis of the seismic attributes in the range of productive reservoir (AV11-2) allowed to forecast the areas of increased effective thickness and porosity of the reservoir in conjunction with the drilling data based on geostatistical dependency. As a result were obtained attribute maps and then maps of effective thickness and the coefficient of porosity of the reservoir AV11-2. These maps, core description and well log information were used for building of the depositional environment model of target horizon. Constructed paleogeographic model show the distribution character of Alym deposits in local scale. According to this model the main reservoirs of the AV11-2 target horizon are Proximal delta front – bay bar deposits.