PHM Finds 106 Million-Barrel Resource in Mature Mahakam Field
Key Takeaways
|
JAKARTA, Investortrust.id — PT Pertamina Hulu Mahakam or PHM has discovered new oil and gas resources in offshore South Mahakam, East Kalimantan through the Metulang Deep MDP-1X exploration well, reinforcing Indonesia energy security by unlocking fresh potential from a mature producing area using near field exploration, the company said on Tuesday, Jan 6, 2026. The discovery is expected to support national oil and gas lifting and slow natural production decline from aging fields.
The company said the MDP-1X well contained an estimated original oil in place of around 106 million barrels of oil equivalent, categorized as contingent resources and slated for fast-track development. The find capped PHM exploration performance in 2025 with a positive milestone for the Mahakam Working Area.
General Manager Setyo Sapto Edi said the discovery demonstrated PHM consistency in sustaining exploration within a mature basin. He said the activity was carried out in close coordination with the Special Task Force for Upstream Oil and Gas Business Activities and the Ministry of Energy and Mineral Resources as sector regulator.
The MDP-1X drilling program was executed under a near field exploration strategy designed as a quick win to accelerate monetization. The approach relied on utilizing nearby existing production facilities, allowing development without large-scale new infrastructure investment.
Amid limited exploration acreage, the company applied updated geological concepts, including a new exploration play concept in long-producing areas. The strategy was aimed at unlocking hidden resources that remained untapped within mature oil and gas fields.
Since taking over operatorship of the Mahakam Block on Jan 1, 2018, PHM has drilled six exploration wells with a high success rate. Four of those wells resulted in discoveries, with MDP-1X considered among the most significant within the working area.
PHM operates as a subsidiary of PT Pertamina Hulu Indonesia, which manages upstream oil and gas assets across Kalimantan. The exploration program aligned with the parent strategy to maintain sustainable energy supply and stabilize long-term production.
Setyo said the company continued to invest in drilling new wells to add reserves, improve recovery, and maintain output from mature assets. He said sustained investment was required to manage decline while optimizing remaining potential in Kalimantan fields.
President Director Sunaryanto said exploration remained a key pillar for energy sustainability. He said the MDP-1X discovery would be developed promptly to support production growth, strengthen Kalimantan energy resilience, and improve the reserve-to-production ratio of Pertamina Hulu Indonesia.
Technically, the MDP-1X well was drilled to a measured depth of 4,260 meters and penetrated the Yakin Formation. The main target interval could only be partially drilled due to high-pressure conditions, but the company identified promising resources in shallower formations.
The productive zones were identified within the Sepinggan Carbonate Sequence and the Sepinggan Deltaic Sequence. These intervals provided an alternative development opportunity with manageable technical risk.
Flow test results from the Sepinggan Carbonate Sequence confirmed strong reservoir performance in both carbonate and sandstone layers. With a tested interval of 25.5 meters, the well recorded a maximum flow rate of about 2,821 barrels of oil per day and gas production of 5 million standard cubic feet per day.
The results validated follow-up evaluation from the Manpatu-1X discovery drilled in 2022. The performance supported the view that mature offshore Mahakam reservoirs still held meaningful commercial potential when approached with updated exploration and development methods.
The discovery added to a broader series of upstream successes recorded by Pertamina upstream units throughout 2025. Earlier in the year, Pertamina Hulu Rokan Zone 4 Prabumulih posted production results far above targets from onshore wells in South Sumatra.
Collectively, the 2025 discoveries strengthened upstream performance following 2024 achievements, when Pertamina Hulu Energi reported more than 1.8 trillion cubic feet of inplace gas resources from discoveries in Central Sulawesi. The combined results highlighted the continued relevance of mature basins in supporting Indonesia long-term energy supply.