USGS estimates oil, gas resources in four Caspian Sea basins

Nick Snow
OGJ Washington Editor

WASHINGTON, DC, Nov. 12 -- Four basins in the Caspian Sea area contain an estimated 19.6 billion bbl of oil, 243 tcf of natural gas, and 9.3 billion bbl of natural gas liquids, the US Geological Survey said on Nov. 9.

The figures represented mean volumes of technically recoverable, conventional, undiscovered resources in the North Caspian, Middle Caspian, North Ustyurt, and South Caspian basin provinces, the US Department of the Interior agency said. The provinces cover 1.315 million sq km, it indicated.

The assessment was based on published geologic information, commercial data from oil and gas wells and fields, and field production records, according to USGS. It said its approach is to define total petroleum systems and assessment units and assess the potential for undiscovered oil and gas resources.

USGS said mean volumes and probability ranges in the North Caspian Basin Province were 4,671 million bbl of undiscovered crude, with a range of 1,278 to 10,565 million bbl; 33,099 bcf of gas (both associated and dissolved, and nonassociated), with a 7,511-83,623 bcf range; and 4,864 million bbl of NGLs, with a 1,294-11,153 million bbl range.

Mean volumes and probability ranges in the North Ustyurt basin were 342 million bbl of crude, with a 118-707 million bbl range; 4,651 bcf of gas, with a 1,339-10,587 bcf range; and 61 million bbl of NGLs, with a 17-140 million bbl range, the report said.

Middle Caspian basin mean volumes and probability ranges were 1,908 million bbl of crude, with a 569-4,200 million bbl range; 8,655 bcf of gas, with a 2,408-20,362 bcf range; and 352 million bbl of NGLs, with a 94-850 million bbl range, it indicated.

South Caspian basin mean volumes and probability ranges were 12,671 million bbl of crude, with a 2,358-32,543 million bbl range; 196,835 bcf of gas, with a 38,330-494,358 bcf range; and 4,002 million bbl of NGLs, with a 760-10,249 million bbl range, the report said.

The full report is available on line at http://pubs.usgs.gov/fs/2010/3094/pdf/FS10-3094.pdf.

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