• Infill drilling operation to commence in Block 22/12, Beibu Gulf, China
• One well program expected to recover 0.4 mmbbl gross (0.1 mmbbl net to Horizon)
• Incremental oil rate of 500 bopd gross (125 bopd net to Horizon)

Horizon Oil Limited has announced the commencement of a 2025 infill drilling operation in Block 22/12, Beibu Gulf, People's Republic of China. A COSL owned drilling rig has been mobilised to the WZ12-8W platform for a one-well campaign, which was spud today. The well is expected to recover incremental oil from an existing field and is targeted as a nearby offset from existing producers. The one-well program is forecast to recover an incremental 0.4 mmbbl gross (Horizon net 0.1 mmbbl) to the end of the contract period, with the total incremental oil rate from the well estimated at 500 bopd gross (Horizon net 125 bopd). Horizon's share of the forecast drilling costs will be funded from existing cash reserves. CNOOC is operating the drilling and completion operation, which will run for approximately 30 days from spud. Horizon CEO, Richard Beament, commented that the drilling operation reinforces the company's commitment to investing in production expansion within one of its foundation assets, and at the same time developing its substantial inventory of contingent resources.