ABSTRACT: Major Petroleum Basins of the USSR: Cratonic Basins and Rifts

Gregory F. Ulmishek

Major cratonic basins of the Soviet Union include the Volga Ural, Timan-Pechora, North Caspian, and Baltic basins on the Russian craton and the Lena-Tunguska, Vilyuy, and Yenisey-Lena basins on the Siberian craton and its margins. The significant productive rift basins are the Dnieper-Donets and Pripyat basins.

The Volga-Ural basin is the largest in this group. Its productive section ranges from the Middle Devonian to the Lower Permian. The main source rock is the Upper Devonian Domanik Formation. Oil and gas fields are in Middle Devonian clastics in structural traps, in Upper Devonian reefs, and in drape structures over the reefs.

The geology of the Timan-Pechora basin is similar to that of the Volga-Ural basin. The main oil production is from Middle Devonian clastics underlying the Domanik source rock. Large gas-condensate reserves are found in folds of the Ural thrust belt on the eastern basin margin. The basin extends offshore into the southern Barents Sea.

A supergiant oil field (Tengiz) and giant gas-condensate fields were recently discovered in the very deep (about 20 km) North Caspian basin. The fields are in carbonate rocks (including reefs) beneath a very thick salt formation of Kungurian (Early Permian) age. Source rocks are supposedly black shale facies beneath the salt.

The poorly explored Lena-Tunguska basin contains oil and gas in Proterozoic and Lower Cambrian clastic and carbonate rocks overlain by thick Cambrian salt. Most production is from structural traps, but reservoir pinch-outs are also important. Source rocks are not well identified but supposedly occur in the Riphean (Upper Proterozoic) section.

The petroleum potential of other basins of this group is significantly smaller.

AAPG Search and Discovery Article #91003©1990 AAPG Annual Convention, San Francisco, California, June 3-6, 1990