Tethys Oil’s net working interest Reserves in Blocks 3&4 Oman as per 31 December 2020 amount to 26,922 thousand barrels of oil (“mbo”) of proven and probable Reserves (2P). The 2P reserve replacement ratio amounts to 120 percent. In addition, Tethys Oil's net working interest resources oil base in Oman amounts to 13,904 mbo of 2C Contingent Resources. The Company’s 2020 and 2019 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 2019 | 17,336 | 26,112 | 36,919 |
| Production 2019 | -4,149 | -4,149 | -4,149 |
| Additions and revisions | 4,761 | 4,959 | 5,104 |
| Total 31 December 2020 | 17,948 | 26,922 | 37,874 |
| Reserve replacement ratio, % | 115% | 120% | 123% |
Additions and revisions include maturation of Contingent Resources to Reserves from the ongoing appraisal program of Ulfa and Erfan 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 8,940 mbo of 1P, 12,176 mbo of 2P and 15,321mbo 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 small contribution from the Anan-1 exploration well, a new discovery at the end of the 2020. Development of the Contingent Resources in the discoveries is continued 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 2020 | 5,022 | 13,904 | 27,911 |
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).