Прогноз геологического строения и нефтегазоносности района острова Тюлений в дагестанском секторе Каспийского моря: 25 лет спустя

Prediction of geological structure and petroleum potential in the Tyuleny Island neighbourhood (the Dagestan Republic sector, Caspian Sea) 25 years later

The authors present structural and geomorphological, and geochemical criteria for forecasting (1997) the petroleum potential of a new local uplift (the Tyuleny Island proper) in the Dagestan sector of the north-western Caspian Sea. The fault-block structural features of this uplift are considered. Structural maps of heterochronous sedimentary unit tops created based on 3D seismic data acquired in 2000–2001are presented. It is noted that predicted local uplift (Tyuleny Island) does not exhibit structural expression in these maps, which made the basis for considering this part of the sea unpromising for structural hydrocarbon trap discovery. At the same time, according to the structural maps created, six buried local uplifts were identified around and near Tyuleny Island; these uplifts were recognized as local structures promising for oil and gas. All of these deep local structures are relatively small in size and coincide in plan with submarine positive local uplifts in the seafloor topography. The authors’ opinion is given on the possible reason for the omission of the largest and central local uplift (the Tyuleniy Island) in the Dagestan sector of the Caspian Sea; the authors consider the “Predicted Central Tyuleniy Uplift” (identified by structural-geomorphological and geochemical methods) promising for oil and gas. It is shown that all oil and gas bearing structures revealed to date (discovered oil and gas fields) and promising local uplifts have an expression in the seafloor neotectonic deformations, which opens up new opportunities for predicting structural hydrocarbon traps in this water area on a new geodynamic basis. © 2025, All-Russian Research Geological Oil Institute (VNIGNI). All rights reserved.