Print this pageAbstract: The Irkutsk Region of Eastern Siberia. Proterozoic and Early Cambrian Exploration Potential
THOMPSON, STEVE*, and VALERY VOROPANOV
The Irkutsk Region lies in southern Siberia to the north and west of Lake Baikal, 4,000 km from Moscow and 2,500 km from the Russian east coast. The region covers approximately 768,000 km2 of which more than 500,000 km2 are prospective. Estimated total recoverable reserves are placed at 59 billion barrels (BBO) and oil equivalent, of which 152 TCF and 26 BBO have been proven to date. Two giant fields have been discovered, Verkhne-Chonskoe (1.5 BBO) and Koviktinskoe (35.5 TCF).
To date most exploration has centered on and around the Nepa-Botuobian basement uplift, lying on trend with hydrocarbon-rich areas in southwest Yakutia. Discoveries have also been made in the lightly explored Angara-Lenskaya and Prisayno-Eniseiskaya areas, where both structural and stratigraphic plays are expected to be the focus of future exploration. Three main play types are recognized. In the north, oil prone Vendian and Lower Cambrian sandstone reservoirs typically produce light gravity crudes. Farther south gas predominates in similar aged clastic reservoirs. Oil saturated Lower Cambrian carbonates of the Ust-Kutsky, Osinsky and Prebrazhensky horizons, sealed by Lower Cambrian evaporites, form the extensive third play, covering most of the northern half of the Nepa-Botubian structure.
Development plans for the expansion of the oil and gas industry are centered on production and export from the Verkhne-Chonskoe and Koviktinskoe fields. Promotion of the area will lead to an International Licensing Round containing acreage with both exploration and development potential.
AAPG Search and Discovery Article #90942©1997 AAPG International Conference and Exhibition, Vienna, Austria