Geology, geography and global energy

Scientific and Technical Journal

Sedimentation Structure of the Lower ViseanTerrigenous Complex in the Stepnovsky Composite Wells

2012. №4, pp. 71-75

Astarkin Anton V. - Post-graduate student, Saratov State University, 83 Astrakhanskaya st., Saratov, Russian Federation, 410012, sv.astarkin@rambler.ru

Goncharenko Olga P. - Professor, Saratov State University, 83 Astrakhanskaya st., Saratov, Russian Federation, 410012, GoncharenkoOP@mail.ru

The article has studied the lithofacies (sedimentation) character of the Nizhnevizeyskogo terrigenous complex at the southeastern end of the Stepnovsky shaft, in Stavropol region. The results of this assessment, and those of parallel synthetic inputs, have indicated that the complex was formed at sea. The evaluation was undertaken as part of a search for prospective oil and gas deposits within the complex’s sedimentation structure. The critique notes, however, that it was difficult to accumulate the conditional sedimentation data due to the often unstable condition of the complex (it had been subject to the sea’s frequent short transgressions and regressions). These unstable conditions had caused fabrication of the different sedimentary deposits during its time of creation. The complex model, which researchers are considering, incorporates several sedimentary deposits including Visean terrigenous ones and several Lower Carboniferous types. Other deposits in the Pred Bobrikovskoe study area have been blurred over time and only appear now in the southern parts of the area. They are marked by 2-4-m-thick mudstone Bobrikov terrigenous rocks overlaying the eroded surface of the Tournaisian stage carbonate deposits. The bottom layer of the geological structure now encompasses re-deposited Bobrikovskoe sediments, which incorporate traces of silicified organogenic-detrital limestone apparently of the Kizelovskaya-Malinovsky age.

Key words: Bobrikovskian horizon,terrigenous reservoirs,lithology and facies analysis,sedimentation model,southeast of the Stepnovsky composite swell

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