Giant gas field of northern West Siberia
The 66 fields discovered since the 1960s in the northern West Siberian basin contain at least 22 trillion m/sup 3/ (777 tcf) of proved gas, almost one-third of the world's reserves. Half of these fields are giants (> 85 billion m/sup 3/ or 3000 bcf of reserves). These include the largest and second-largest gas fields in the world-Urengoy (8.099 trillion m/sup 3/ or 286 tcf of gas) and Yamburg (4.81 trillion m/sup 3/ or 170 tcf of gas)-as well as most of the other ten largest gas fields in the world. The West Siberian basin occupies a 3.4-million km/sup 2/ (1.31-million mi/sup 2/) arctic lowland immediately east of the Ural Mountains, extending north under the Kara Sea. It is a composite basin, with Mesozoic-Cenozoic basin fill on top of a Paleozoic basin that overlies a crystalline Archean-Proterozoic framework. The productive zones in the northern basin are principally in the Neocomian section (at an average depth of 2800m or 9200 ft) and the Cenomanian section (at an average depth of 2800 m or 9200 ft) and the Cenomanian section (at an average depth of 1100 m or 3600 ft). The former contains reservoirs with gas, condensate, and oil; the latter contains two-thirds of the region's gas. Gas in Cenomanian reservoirs is almost pure methane. Hydrocarbons in Neocomian reservoirs were generated by thermal maturation of sapropelic organic matter contained principally in the Tithonian Bazhenov shale. Methane in the Cenomanian section appears to be a combination of thermogenic gas from the Bazhenov Suite (or deeper) and biogenic gas generated in the Cenomanian section itself, although workers disagree over how much gas came from each source. Continental glaciation during the Pleistocene may have been important in concentrating the methane in Cenomanian reservoirs.
- Research Organization:
- Louisiana State Univ., Baton Rouge
- OSTI ID:
- 7148174
- Journal Information:
- Am. Assoc. Pet. Geol., Bull.; (United States), Vol. 70:6
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
NATURAL GAS FIELDS
GEOLOGY
SIBERIA
METHANE
ORIGIN
RESERVES
SEDIMENTARY BASINS
SHALES
ALKANES
ASIA
EASTERN EUROPE
EUROPE
GEOLOGIC DEPOSITS
GEOLOGIC STRUCTURES
HYDROCARBONS
MINERAL RESOURCES
NATURAL GAS DEPOSITS
ORGANIC COMPOUNDS
RESOURCES
ROCKS
SEDIMENTARY ROCKS
USSR
030200* - Natural Gas- Reserves
Geology
& Exploration