M. Fedorova*, O. Kirzelyova, T. Kiryanova, R. Kopenkin, D. Klyazhnikov (Ingenix Group), A. Kalugin (LUKOIL Engineering)
Thick sedimentary series potentially promising for HC deposits formation and preservation were accumulated in the Early-Middle Jurassic time in the lands of Shaimsky and neighbouring Krasnoleninsky petroleum districts; they are Sherkalinsky and Tyumen formations. Accumulation of Sherkalinsky and Tyumen formations (J10 and J9-J2 reservoirs) occurred against the background of the territory downwarping and natural evolution of depositional settings from paleohighlands and slopes, accumulative valleys, to shallow marine environments.
Using the frequency decomposition method and subsequent RGB blending, analysis of well log diagrams, results of core lithofacies analysis, the sequential conceptual model of deposition of Early-Middle Jurassic productive series in the area of large multiplay field was created. The authors delineated the following different facies zones: slopes of highlands with proluvial fans; fluvial, lacustrine-boggy plains; subaerial and submarine delta parts; shallow-marine shore. Boundaries of separate sand bodies having different genesis were determined, they are: channels, delta lobes and front, delta distributary channels, longshore bars.