Since 1959 more than 114 oil and gas fields estimated to contain more than 4 billion tons (28 billion bbl) have been discovered in the West Siberian Lowland, a topographic and structural basin east of the Ural Mountains. About 1,750,000 sq km (675,000 sq mi), an area nearly three times that of Texas, is considered prospective. The bottom of the basin consists of igneous and metamorphosed Paleozoic rocks at an average depth of 3,000 m (10,000 ft) in the south, and 4,000 m (13,000 ft) in the north. All productive strata are sandstones of Late Jurassic and Cretaceous ages.

All fields discovered to 1970 are on anticlinal structures, found mainly by geophysical work, including magnetic, gravity, and seismic profiling. Detailed seismic work was begun only in 1964. Producing structures consist of irregularly shaped areas of closure on large anticlinal "arches." Most fields are medium size, covering less than 100 sq km (25,000 acres), and contain less than 30 m (100 ft) of pay sandstone. Average depth of the wells is 2,500 m (8,000 ft). Several pools are large in area, but medium size in reserves. A few pools contain over 300 million tons (2.1 billion bbl), of which the largest is Samotlor with slightly more than 2.5 billion tons (15.1 billion bbl). Halbouty et al. included eight other West Siberian fields among the giant oil fields of the world. Several lar e gas fields have been discovered in the northern part of the basin, with proved reserves of 9 trillion cu m (315 trillion cu ft). The basin is still largely unexplored, and reserves of oil and gas will be at least doubled and probably quadrupled in the next few years.

The oil fields are about 700 km (400 mi) north of a thickly populated farming and industrial area crossed by several railroads, and are accessible by large rivers which are navigable in summer. Although the fields are about 2,700 km from Moscow, transporting the oil to market seems no more difficult than in the Alberta basin. The gas fields are more remote, but construction of a 2.5-m (100 in.) line has already begun.