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A New Look at Geological Structure of Pashian Horizon (D3ps) of Aznakaevskaya Area, Romashkinskoye Oil Field

Z.A. Loshheva1, M.Sh. Magdeev1, S.G. Agafonov1, M.V. Fedotov1, O.V. Magdeeva2

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This paper considers construction of a geological model for the Pashian Horizon (D3ps) of Aznakaevskaya Area, Romashkinskoye Oil Field. Facies analysis is proposed for determination of spatial arrangement of the facies that contain reservoir beds. Development strategy designed and implemented based on the existing geological model does not ensure desired economic and production performance. The new model designed using facies analysis and up-to-date IT tools (IrapRMS ROXAR software package) with account of tectonic factor enables changing the philosophy and the approach to searching for remaining reserves in poorly swept or by-passed zones. During the Pashian, coastal-marine and offshore facies accumulated within the field: wave-cut zone – basal layer; lagoon zone – lagoon clays; intertidal zone – bar layer and tidal channel (replaces bar sediments); behind-bank zone – behind-bank clays, and alluvial fan facies that overly the behind-bank clays. Fluvial palaeovalleys were also present and contained compound fluvial channel and wave-cut facies. Throughout the geological history, multiple tectonic movements occurred and influenced the architecture of the deposited facies. At the first stage, well logging data were used to analyze each well and describe the standard cross section with the following facies from bottom to top: basal layer, lagoon clays, bar layer, behind-bank clays. Four cross section types were singled out taking into account secondary facies with regular-sporadic development. In the course of the research, core data on reservoir quality were analyzed to confirm separation into compound and intertidal facies. Porosity distribution histograms were also generated based on well logging findings. The authors of this work believe that the new geological model and the subsequent reservoir simulation model will allow to work out a successful production enhancement strategy to recover the remaining oil reserves localized in poorly swept or by-passed zones.

Modeling, geological model, well logging, basal-bar layer, behind-bank clays, channel deposits, horizon

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1Tatneft PJSC, Almetyevsk, Russia
2Scientific and Production Centre «Neftegazovye tehnologii», Bugulma, Russia

For citation:

Loshheva Z.A., Magdeev M.Sh., Agafonov S.G., Fedotov M.V., Magdeeva O.V. A New Look at Geological Structure of Pashian Horizon (D3ps) of Aznakaevskaya Area, Romashkinskoye Oil Field. Georesursy = Georesources. 2017. V. 19. No. 1. Pp. 21-26. DOI: