The Bazhenov Formation or Bazhenov Shale is a geological stratum in the West Siberian basin. It was formed from sediment deposited in a deep-water sea in Tithonian–early

Berriasian In the geological timescale, the Berriasian is an age/stage of the Early/Lower Cretaceous. It is the oldest subdivision in the entire Cretaceous. It has been taken to span the time between 145.0 ± 4.0 Ma and 139.8 ± 3.0 Ma (million years ago ...

time. The sea covered more than one million square kilometers in the central basin area. Highly organic-rich siliceous shales were deposited during this time in anoxic conditions on the sea bottom. The sea was connected to the world's oceans and contains trace minerals derived from dissolved minerals and organic materials similar to

sapropel Sapropel (a contraction of ancient Greek words ''sapros'' and ''pelos'', meaning putrefaction and mud (or clay), respectively) is a term used in marine geology to describe dark-coloured sediments that are rich in organic matter. Organic carbon con ...

sediments in the

Black Sea The Black Sea is a marginal mediterranean sea of the Atlantic Ocean lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bounded by Bulgaria, Georgia, Rom ...

. In addition to being a prolific deep water marine

source rock In petroleum geology, source rock is rock which has generated hydrocarbons or which could generate hydrocarbons. Source rocks are one of the necessary elements of a working petroleum system. They are organic-rich sediments that may have been depo ...

(the International Energy Agency has called it the world's largest oil source rock) the formation is believed to contain substantial reserves of unconventional liquid hydrocarbons in form of

tight oil Tight oil (also known as shale oil, shale-hosted oil or light tight oil, abbreviated LTO) is light crude oil contained in unconventional petroleum-bearing formations of low permeability, often shale or tight sandstone. Economic production from ...

and solid hydrocarbons in form of

kerogen Kerogen is solid, insoluble organic matter in sedimentary rocks. Comprising an estimated 1016 tons of carbon, it is the most abundant source of organic compounds on earth, exceeding the total organic content of living matter 10,000-fold. It ...

. These deposits occur at depths of with the thickness from . An estimate by

Wood Mackenzie Wood Mackenzie, also known as ''WoodMac,'' is a global research and consultancy group supplying data, written analysis, and consultancy advice to the energy, chemicals, renewables, metals, and mining industries. In 2015, the company was acquire ...

of the Bazhenov Formation puts oil in place at . In 2013, the Russian oil company Rosneft estimated recoverable reserves of for the formation. The Russian government agency Rosnedra estimated in 2012 that the Bazhenov contained 180 to 360 billion barrels of recoverable reserves.Nadia Rodova
Will Russia replicate US success in tight oil development?
Platts, 23 August 2012. According to U.S. Energy Information Administration estimates published in June 2013, the total Bazhenov shale prospective area has a resource of a risked tight oil in-place of and a risked

shale gas Shale gas is an unconventional natural gas that is found trapped within shale formations. Since the 1990s a combination of horizontal drilling and hydraulic fracturing has made large volumes of shale gas more economical to produce, and some ...

in-place of , with of oil and of gas as the risked, technically recoverable. Total hydrocarbon resources are estimated in 50 to 150 billion tonnes.

References

{{Coord missing, Russia Geologic formations of Russia Geology of Siberia Jurassic System of Asia Lower Cretaceous Series of Asia Cretaceous Russia Jurassic Russia Berriasian Stage Tithonian Stage Shale formations Source rock formations Oil fields of Russia