The Bussabong gas field is an offshore gas development located in the Gulf of Thailand.
The project is being executed by Thailand state-backed PTT Exploration and Production Public Company (PTTEP) through its wholly owned subsidiary PTTEP Energy Development Company (PTTEP ED), which holds a 60% operating interest, alongside Canadian upstream operator Valeura Energy, which holds a 40% non-operated working interest.
Recommended Buyers Guides
The joint venture (JV) reached a final investment decision in September 2026 for the first phase of the project.
Construction and field development are scheduled to take approximately two years, with first gas planned for 2028.
Bussabong gas field phase one output is expected to begin at approximately 30 million standard cubic feet per day (mscf/d) before expanding to 40mscf/d by 2030 to meet the domestic energy demand in Thailand.
Development background
In March 2023, PTTEP ED secured exploration and production rights for offshore blocks G1/65 and G3/65 under the 24th Petroleum Bidding Round administered by the Department of Mineral Fuels within the Ministry of Energy.
The awards were finalised under production sharing contracts (PSCs) following approval from the Thai Cabinet, granting PTTEP ED an initial 100% operating interest in both concessions.
In July 2025, PTTEP entered into a farm-in agreement with Valeura Energy for a 40% undivided working interest in both blocks. The Thai Cabinet approved the transfer of the interest in September 2026. PTTEP retains the remaining 60% interest and continues as operator.
The governing PSC framework establishes a 10% royalty on gross revenue payable to the Thai Government, cost recovery capped at 50% of gross revenue, and an equal 50% government and 50% contractor share of remaining profit from oil and gas. Contractor net profits face a corporate income tax rate of 20%.
The exploration phase runs for six years until May 2029, with a three-year extension option. Minimum work requirements mandate acquiring 800km² of 3D seismic data, (comprising 500km² in G1/65 and 300km² in G3/65. Also included are the drilling of eight exploration wells, five on G1/65 and three on G3/65.
Any commercial discoveries moved into development receive a 20-year production term, with provision for a further ten-year extension.
Bussabong gas field location
The Bussabong gas field lies in the eastern section of Block G3/65 in the northern Gulf of Thailand.
The total block spans approximately 11,646km² and extends roughly 200km (124 miles) along the north-western flank of the North Malay basin, containing seven identified oil and gas discoveries confirmed by 15 wells encountering hydrocarbon pay.
The acreage sits adjacent to producing fields operated by PTTEP, including G1/61, G2/61 and Arthit, offering immediate operational synergies.
Exploration has defined two primary sectors on Block G3/65, comprising the Nong Yao North-East area and the Bussabong-Angun area, with the latter selected as the site for phase-one development.
Exploration and discovery
Subsurface technical evaluations at the Bussabong area began in 2023, followed by geological modelling and petroleum resource assessments in 2024 to support exploration drilling and 3D seismic processing.
In 2025, drilling operations at the BUSSABONG-09 exploration well confirmed natural gas reserves, prompting the formal submission of an application to the Department of Mineral Fuels to designate the Bussabong production area.
The JV plans further exploration work across Block G3/65, including drilling of an exploration well in the Nong Yao Northeast prospect to evaluate regional hydrocarbons. A commercial find in this prospect will offer potential to expand production capacity across the block in subsequent phases.
Bussabong gas field development details
The Bussabong gas field development strategy integrates Bussabong with existing offshore production facilities at the neighbouring North Bongkot field in Block G2/61, which is also operated by PTTEP.
Subject to regulatory endorsement of the underlying commercial terms, this infrastructure-sharing structure removes the need for stand-alone processing facilities.
The initial infrastructure will comprise two wellhead platforms, each configured with 24 well slots, installed across the northern area of the Bussabong field in water depths ranging from 75m (246ft) to 90m. Natural gas produced from the project will be transported 9km east through a 12in subsea pipeline directly to the Bongkot central processing platform, where existing capacity will accommodate field volumes.
