Studies of modern geodynamics of exogenous morphogenesis in the Republic of Tatarstan to ensure environmentally friendly development of heavy oil fields

UDK: 502.55:553.98(470.41)

Key words: exogenous processes, neotectonics, morphostructural and space geological investigation, aerial geological survey, geomorphologic survey, zones of weakness, upward flow

Authors: M.N. Mingazov, A.A Strizhenok, P.N. Kubarev (TatNIPIneft, RF, Bugulma)

To ensure environmental and occupational safety during the development of heavy oil fields desktop and field surveys were performed to understand the dynamics of exogenous surface relief formation. The surveys involved applied morphostructural studies, aerial and space geological investigations (aerial photo interpretation). The surveys provided insight into the tectonic processes in the region and allowed identifying zones of weakness that might serve as paths for breakthrough of reservoir fluids or heat carrier across vadose zones in the course of heavy oil production. Landforms and morphogenesis processes are the results of complex interactions between exogenous and endogenous activity, with the prevailing role of the latter. Studies of the dynamics and intensity of current landscape shaping processes provided geoindicators of modern relief pattern alterations.

Desktop surveys included interpretation of large-scale aerial photographs and topographic maps to study the dynamics of exogenous processes within the Cheremshano-Bastrykskaya zone. Based on the results of these research activities, areas of anomalous exogenous morphogenesis were identified, these exhibiting almost the full range of geoindicators of active geodynamic environment.   Fracture pattern of Upper Permian deposits was established.

A map of recent tectonics of the Cheremshano-Bastrykskaya zone on top of the Asselian was created to shows surface elevations and depressions in the Asselian structural plan. To reduce ecological risks, heavy-oil wells should not be located in zones of negative elevations (TVDSS) because downward movements of crustal blocks squeeze hydrocarbons and reservoir fluids out of production intervals, thereby destroying hydrocarbon accumulations.

According to research findings, the dynamics and intensity of exogenous morphogenesis in the Cheremshano-Bastrykskaya zone are sufficient for erosion and fluvial processes to take place in Upper Permian bitumen reservoirs. This may be one of the causes of breakthrough of heat carrying agents or reservoir fluids towards fresh water layer and day surface.
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