Tethys Oil’s net working interest Reserves in Blocks 3&4 Oman as per 31 December 2021 amount to 26,174 thousand barrels of oil (“mbo”) of proven and probable Reserves (2P). The 2P reserve replacement ratio amounts to 82 percent. In addition, Tethys Oil's net working interest resources oil base in Oman amounts to 15,600 mbo of 2C Contingent Resources. The Company’s 2021 and 2020 year-end Reserves reports were audited by ERC Equipoise Limited (“ERCE”) as independent qualified Reserves evaluator.
| Development of Reserves, Blocks 3&4 (Audited) | |||
| mbo | 1P | 2P | 3P |
| Total 31 December 2020 | 17,948 | 26,922 | 37,874 |
| Production 2021 | -4,057 | -4,057 | -4,057 |
| Additions and revisions | 3,366 | 3,309 | 5,587 |
| Total 31 December 2021 | 16,645 | 26,174 | 38,449 |
| Reserve replacement ratio, % | 83% | 82% | 137% |
Additions and revisions include maturation of Contingent Resources to Reserves from the ongoing appraisal program of Ulfa, Erfan and Anan fields as well as upside revisions of the Reserves on the Farha South and Shahd fields.
Based on ERCE’s model and current oil price assumptions, Tethys Oil’s net entitlement Reserves (Reserves after government take) amount to 7,825 mbo of 1P, 10,786 mbo of 2P and 14,233 mbo of 3P.
In addition to Reserves, Tethys Oil also announces net working interest Contingent Resources. The bulk of the estimated Contingent Resources are contained in the Ulfa, Samha and Erfan fields with a contribution from extensions in the Shahd fields. Development of the Contingent Resources in the discoveries is contingent upon the on-going appraisal programme, a committed work programme as well as budget to access these resources.
| Contingent Resources, Blocks 3&4 (Audited) | |||
| mbo | 1C | 2C | 3C |
| Total 31 December 2021 | 5,640 | 15,600 | 33,360 |
The audit of the Reserves in Oman have been conducted using 2018 Petroleum Resources Management System (PRMS2018), sponsored by the Society of Petroleum Engineers (SPE), World Petroleum Council (WPC), American Association of Petroleum Geologists (AAPG) and Society of Petroleum Evaluation Engineers (SPEE).