T. Kiryanova*,  O. Kirzeleva, M. Fedorova, R. Kopenkin, D. Klyazhnikov (Ingenix Group), A. Kalugin (LUKOIL Engineering)

Tyumen series within the West Siberian Petroleum Province contain considerable oil resources (about 3 billion tons of the current recoverable reserves). Degree of their depletion is only 7%. Until recently, the reason for low interest in reservoir development was the frequent disconfirmation of geological models and drilling of numerous dry and marginal wells.
Despite the considerable amount of accumulated information, including regional studies, and conclusions that in the vast territory the Tyumen series were formed in continental settings of alluvial plains and meandering channels, conceptual and three-dimensional digital models are still created with large assumptions/simplifications and do not reflect the complexity of pay zone structure. That is why the subsequent drilling does not support geological models.
By the example of J2 reservoir in two fields, the work presents an experience of transition from simple to more complicated geological models as a result of reprocessing and integrated interpretation of geological and geophysical information.
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.
D. Klyazhnikov* (Ingenix Group), V. Pankov (Lomonosov Moscow State University)

Lower Permian carbonate deposits are widespread on the territory of the Russian plate, including on its Eastern outskirts, within the Urals. They are characterized by extensive lithofacial heterogeneity, significant variability of porosity and permeability, the predominant development of low-pore reservoirs. The paper presents a comparative analysis of the lower Permian carbonate deposits confined to the Northern and southern parts of the pre-Ural regional deflection. A similar lithological structure of sediments, due to the common spatial and temporal features of the territory, allows to perform such a comparison. For the analysis, the results of the core study and GIS data on the Kochmes field located in the Northern part of the Urals, and a number of areas in the South – Nagumanovskaya, Peschanaya, Vershinovskaya etc. On the basis of sequence stratigraphy method involving sedimentological and lithological-petrographic study of the core, the main facies of the situation were identified. Evaluation of the lithological volume model and permeable identification were carried out using lithodensity log, spectral gamma-ray log, cross-dipole array sonic log etc. The most high-capacity rocks are confined to facies of organogenic buildings in the southern part of the pre-Ural regional deflection, with a predominance of porous-cavernous and porous reservoirs.
O. Kirzelyova*, T. Kiryanova, M. Fedorova, R. Kopenkin, D. Klyazhnikov (Ingenix Group), A. Kalugin (LUKOIL Engineering)

The presentation uses a real example to discuss the methodology for mapping different facies objects associated with the Tyumen J2 reservoir, namely: lacustrine-boggy zones; paleochannels; fans, etc. Five 3D survey datasets acquired and processed in various years were used in this work. The authors also demonstrate the possibility of the identified paleochannel objects ranking into sand and shaled-out beds according to a number of certain features.
"Nowadays, attention is being increasingly focused on the Tyumen pay zones of the West Siberian Petroleum Province, which contain difficult-to-recover oil reserves. Laterally and vertically
discontinuous and thin sand reservoirs with lower reservoir quality are typical of this sedimentary complex of continental genesis.
However sometimes, well data show significant growth of reservoir thickness (exceeding 10 m) and increasing values of such parameters as porosity and permeability.
Basing on sedimentological description of core it is proved that such wells penetrate channel deposits.
This fact determines the subsequent work objective for multi-disciplinary teams (geophysicists, geologists, petrophysicists, reservoir engineers)......."
An approach to creating conceptual geological models 

This paper presents the methodological approaches to investigations of the West Siberian hydrocarbon bearing formations of the Tyumen series.
The results of building the conceptual geological model of the J2 formation in one of the fields in Ob River Region (so called Latitudinal Ob) are discussed.
How geological model determines the results of field production 

Reliability of field geological models primarily depends on the input geological and geophysical information, technologies being used, and expertise of specialists involved in the project. The mere words “high-quality well log and seismic data” mask heavy expenses. It is necessary not only to register standard well log suite but also to perform full-wave acoustic, density, NMR, and Fullbore Formation Microlmager (FMI) logging... Creation of relevant model of the field is a considerably expensive task. But what should we do when high quality of geological and geophysical information remains only a dream? How to build a reliable 3D geological model in the case of lack of input data? How to make a critical decision about the future of certain oil and gas asset that is in the stage of exploration or placing in operation? Experts from Ingenix Group answer this and some other questions.
This paper discusses an experience of building conceptual model and studies of former Later Ordovician glacial deposits in the territory of present-day North Africa.
Studies and modelling of complex reservoirs of this type is based on integrated analysis of core and well log data, drilling wells, and 3D seismics.