Print this pageReservoir Development in Upper Devonian Carbonates, Timan-Pechora Basin, Russia -- An Assessment of the Causative Factors
BHATTACHARYYA, D., R. RESSETAR, N. BELYAEVA, B. PIMENOV, and A. KORZOUN
The Upper Devonian carbonate sequence in the Timan-Pechora Basin forms a part of the "second" order sedimentary cycle of Eifelian to Tournaisian age in the basin. It consists of several shoaling-up parasequences of algal bioherms in the lower part, and peloidal grain-shoals in the upper part that were deposited in response to tectono-eustatic cycling of "third" and "fourth" order within the basin. The bioherms and the grainshoals in these parasequences house substantial hydrocarbon reserves in specific locations.
Analysis of the causes of such site-specific reservoir development indicates the control of four major factors. Sequentially, these are: 1. basin configuration controlling the deposition of reservoir and nonreservoir facies in specific locations; 2. diagenetic factor (i.e., karstification and/or dolomitization of the reservoir facies) at low-stands controlling the reservoir quality; 3. optimum seal formation during high-stands, and 4. structural/stratigraphic factor controlling the geometry of the reservoirs.
Assessement of relative importance of the causative factors suggest that convergence of all these factors was necessary for the development and distribution of the Upper Devonian reservoirs in the basin.