Commercial reserves and contingent resources summary
(unaudited working interest basis)
Year ended 31 December 2011
| West and North Africa | South and East Africa | Europe, South America and Asia | Total | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Oil mmbbl |
Gas bcf |
Oil mmbbl |
Gas bcf |
Oil mmbbl |
Gas bcf |
Oil mmbbl |
Gas bcf |
Petroleum mmboe |
||||
|
||||||||||||
| Commercial reserves | ||||||||||||
| 1 January 2011 | 245.9 | 22.0 | – | – | 1.7 | 258.5 | 247.6 | 280.5 | 294.4 | |||
| Revisions | 8.1 | (0.8) | – | – | – | 8.7 | 8.1 | 7.9 | 9.4 | |||
| Acquisitions | 9.0 | – | – | – | 0.1 | 79.4 | 9.1 | 79.4 | 22.3 | |||
| Additions | – | – | – | – | – | – | – | – | – | |||
| Production | (20.6) | (2.2) | – | – | (0.2) | (43.9) | (20.8) | (46.1) | (28.5) | |||
| 31 December 2011 | 242.4 | 19.0 | – | – | 1.6 | 302.7 | 244.0 | 321.7 | 297.6 | |||
| Contingent resources | ||||||||||||
| 1 January 2011 | 120.7 | 798.1 | 772.5 | 301.7 | – | 98.9 | 893.2 | 1,198.7 | 1,093.1 | |||
| Revisions | 2.6 | (7.0) | 14.3 | 79.3 | – | – | 16.9 | 72.3 | 29.0 | |||
| Acquisitions | 25.1 | 393.3 | – | – | – | 94.0 | 25.1 | 487.3 | 106.3 | |||
| Additions | 60.3 | 146.4 | 113.7 | – | 36.6 | – | 210.6 | 146.4 | 235.0 | |||
| Disposals | (18.2) | – | – | – | – | – | (18.2) | – | (18.2) | |||
| 31 December 2011 | 190.5 | 1,330.8 | 900.5 | 381.0 | 36.6 | 192.9 | 1,127.6 | 1,904.7 | 1,445.2 | |||
| Total | ||||||||||||
| 31 December 2011 | 432.9 | 1,349.8 | 900.5 | 381.0 | 38.2 | 495.6 | 1,371.6 | 2,226.4 | 1,742.8 | |||
The Group provides for depletion and amortisation of tangible fixed assets on a net entitlements basis, which reflects the terms of the Production Sharing Contracts related to each field. Total net entitlement reserves were 260.6 mmboe at 31 December 2011 (31 December 2010: 231.6 mmboe).
Contingent Resources relate to resources in respect of which development plans are in the course of preparation or further evaluation is underway with a view to development within the foreseeable future.
