The Bazhenov Formation (Tithonian to Berriasian) occupies about 1 million km 2 in the central part of the West Siberian plate and is buried by 2,000 to 3,000 meters of younger sediments. The aggregate mass of organic matter in the Bazhenov Formation is as high as 18 trillion tons (126 trillion barrels of oil equivalent). It is known as one of the largest oil sources in the world. About 500 samples from 39 oil wells throughout the formation were analyzed; it was shown that Bazhenov rocks contain more U, Mo, V, Cu, Zn, and Ni than average black shales; moreover, the concentrations of these elements increase toward the center of the paleobasin.
There can be 6 to 8 barrels of oil in a ton, depending on density.
Bazhenov-Neocomian oil formation
The formation feeds conventional oil fields. Those conventional oilfields have over 144 billion barrels of oil. There have been some wells drilled into the Bazhenov tight oil area and those are producing 400 barrels of oil per day, which is similar to the productivity of Bakken oil wells.
Russia has the potential to develop the Bazhenov Formation to remain and energy superpower for another 100 years.
Estimating oil reserves from 2000
In light of the above it is interesting to estimate oil reserves on the basis of the following considerations. Let us assume that the productive pay area controlled by the AHFP zone is equal to this zone, i.e., 15,600 sq km, and that the net pay is equal to the vertical extent of fractures, i.e., 350 m. Let the fracture volume be 0.3% (f = 0.003). At oil density of 0.8 t/cu m and oil formation factor 1.4 (parameters typical of Jurassic oils) the oil reserves calculated by the volumetric method are in excess of 9 billion tons.
We want to emphasize that these are recoverable reserves, because we calculate only the amount of oil contained in the fractures; if proper oil production technology is used, all oil will be recovered. In this connection we want to say that the depletion drive pilot production of Jurassic reservoirs has already yielded almost 300,000 tons in some wells.
It should be also noted that in this reserve calculation we used minimum parameters deliberately. But there are good reasons to assume greater productive pay area, net pay, and fracture porosity. With account of such changes the volume of the oil-filled fractures will increase at least 2-3 times and oil reserves will amount to 20-30 billion tons (140 billion to 210 billion barrels).
Historical Bakken Estimates
USGS technically recoverable oil 1995 estimate was 151 million barrels of oil for the Bakken.
(USGS 2007) North Dakota and Montana have an estimated 3.0 to 4.3 billion barrels of undiscovered, technically recoverable oil in an area known as the Bakken Formation
Recoverable oil Bakken estimate 2010 by Continental Resources was 24 billion barrels.
Recoverable oil Bakken estimate 2012 by Continental Resources is 27 to 45 billion barrels.
If the Bazhenov is Similar to Bakken
The 2000 estimate of 140 to 210 billion barrels of recoverable oil could be 15 to 100 times too low. The increase would be because of the improved horizontal drilling technology enabling a higher recover rate.