Masirah Oil Limited on Feb, 05 2026 released an independent Summary Qualified Person’s Report showing updated remaining reserves for the Yumna Field in Block 50, offshore Oman, as at Dec, 31 2025.

The audit, prepared by Exceed Torridon Ltd, states that the field has produced about 9.6 million stock-tank barrels (MMstb) of oil to date. Gross 1P, 2P and 3P reserves after economic limit tests are now assessed at 4.36 MMstb, 4.93 MMstb and 5.36 MMstb respectively. On an 87.5 per cent net entitlement basis, this equates to 3.82 MMstb (1P), 4.31 MMstb (2P) and 4.69 MMstb (3P).

Economic cut-off dates for the 1P, 2P and 3P cases are March 2030, Aug, 2030 and Jan, 2031 respectively, based on a Brent price forecast from three independent consultants. The study applies Petroleum Resources Management System guidelines and assumes continued production from five existing wells plus three approved new development wells.

Masirah plans to spud sidetrack well Yumna-6 in the first half of 2026, followed by Yumna-7 and Yumna-8, to accelerate recovery and extend field life. The field, which lies in 30 metres of water, is operated by Masirah Oil and is 87.5 per cent owned by Singapore-listed Rex International Holding. The production licence for Block 50 expires on Jul, 12 2030 or when economic limits are reached.

The report highlights a recovery factor exceeding 55 per cent, supported by strong aquifer drive and high reservoir permeability in the Campanian Lower Aruma Sandstone Formation. No risk factors were applied to the reserves estimates.