West Siberian’s oil reserves increased by 81%

West Siberian Resources Ltd’s net proven and probable (2P) oil reserves as of January 1, 2007 increased by 81% to 306.8 million barrels. The increase in 2P reserves represents a reserve replacement ratio of 222%, excluding acquisitions. 3P reserves (proven, probable and possible) increased to 445.6 million barrels (255.5) million barrels.

West Siberian’s oil reserves have been revised following a recent independent reserve appraisal conducted by DeGolyer and MacNaughton, in accordance with reserve definitions consistent with those approved in March 1997 by Society of Petroleum Engineers (SPE). DeGolyer and MacNaughton is a leading international petroleum consulting firm with an extensive reserve estimation practice in Russia.

Since last years reserve report, proven and probable oil reserves of 140.6 million barrels were added through acquisitions, successful drilling, and reserve revisions. Including the possible category, total oil reserves increased by 78% to 445.6 million barrels. The increase in 2P reserves, excluding acquisitions, of 18.4 million barrels indicates that 222% of the total 2006 oil production of 8.3 million barrels was replaced.

Oil reserves increased in all operating regions. In the Timano Pechora region, a total of 122.2 million 2P and 176.7 million 3P barrels of oil were added through the Northoil-acquisition, including an upward revision of reserves in the Kolvinskoye oil field following the closing of the acquisition. The reserve appraisal does not reflect the recent acqusition of 3D seismic covering the North Kharyaga and Lek Kharyaga fields, which is expected to result in further upward reserve revisions.


SPE Classification
'000 bbl Proved Probable Possible Total 3P
Tomsk region 20,786 44,608 21,600 86,994
oil fields

Timano-Pechora 74,801 139,169 106,046 320,016
region oil fields

Volga-Ural fields 14,777 12,695 11,127 38,599

Total oil reserves 110,363 196,472 138,773 445,608