The West Siberian Basin is the largest oil and gas producing region in the FSU, both in the geographical area it covers and the recoverable oil and gas that it contains. The basin covers an area of approximately 3.4 million square kilometres which is more than twice the size of the state of Alaska.
Topographically the basin is one of the world’s largest areas of unbroken terrain. The region is characterized by water logged soils, shallow lakes and extensive swamps. Winters are severe and last seven to nine months of the year with mean temperatures ranging from about −15° C to −30° C. These winter conditions support better access to the fields, particularly in newer areas of development that have negligible infrastructure. Winter roads, or barge access in the brief summer if waterways exist, are the easiest and least expensive way to ship goods and people to producing fields.
The oil resources in the West Siberian basin are extremely large in absolute terms. The US Geological Survey estimates volumes of discovered hydrocarbons in the basin are 144 billion barrels of oil and more that 1,300 trillion cubic feet of gas. Estimated ultimate recovery is almost 232 billion barrels of oil. Approximately 70% of the oil produced in Russian comes from the West Siberian Basin. PetroNeft Resources’ Licences No. 61 (Tungolsky) and No. 67 (Ledovy) extend over a combined area of 7,439 square kilometres in the eastern portion of the basin. The area is under explored because of the multibillion barrel oil fields that are located in the region, which were a priority for early development.
The structure of the Jurassic Cretaceous strata of the West Siberian basin is a gentle depression superimposed on various Paleozoic structures and early Triassic Rifts. The largest oil reserves are concentrated in the core of the Basin primarily in stacked reservoirs of Necomian age overlying the Bazhenov Formation. The Upper Jurassic rocks, PetroNeft’s Main target horizon, immediately below the Bazhenov Formation, are also regionally oil rich and provide a primary target on the basin margins.
After Gregory F. Ulmishek,
2003, Petroleum Geology and Reservoirs of the West Siberian Basin,
USGS Geological Survey Bulletin