Southeast Asia richer for its ‘biggest’ black gold find in two decades and third largest since 2000

January 7, 2026, by Melisa Cavcic

With the appraisal insights regarding an oil find offshore Vietnam coming to light, Wood Mackenzie, an energy intelligence group, has labeled this hydrocarbon exploration success as “the biggest oil discovery in Southeast Asia of the last 20 years,” perceived to offer a potential lifeline to Vietnam’s declining oil production.

Once Murphy Oil’s preliminary appraisal results of the Hai Su Vang (HSV) discovery in Vietnam’s offshore Cuu Long Basin became available, Wood Mackenzie interpreted the findings to position the discovery as the largest oil find in Southeast Asia of the last two decades and the third largest one in the region since 2000, as the HSV-2X appraisal well encountered 429 feet of oil across two reservoirs and tested at 6,000 barrels per day of 37° API oil.

The energy intelligence group believes that the discovery offers Vietnam a chance to reverse a two-decade production decline, after its oil output fell from 365,000 barrels per day in 2005 to below 120,000 b/d in 2025.

As a result, the latest oil discovery is deemed to arrive at a critical moment for the country’s ongoing offshore licensing round, which includes Cuu Long Basin acreage, since the confirmation of a discovery of this magnitude in a mature basin is expected to attract renewed exploration interest.

Given that Vietnam has been known for slow regulatory processes and a lack of data transparency, which has deterred potential investors and delayed new developments, WoodMac claims that commercialization speed will test the country’s recent regulatory reforms.

“Positive changes to the petroleum law in 2023 and new leadership at the Ministry of Industry and Trade aim to improve investor confidence, but execution will be key,” highlighted Jasman Adam Leong, Senior Analyst at Wood Mackenzie.

Murphy is said to have revised its recoverable reserves estimate toward the upper end of the 170-430 million barrels of oil equivalent (mmboe) range previously announced, with additional shallow reservoir sections providing further upside potential.

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The HSV find is described as the firm’s second major oil discovery in Southeast Asia, following its 2002 Kikeh find offshore Malaysia. The company sold its Malaysian portfolio to PTTEP in 2019 and has since pivoted to Vietnam, where it is also developing the Lac Da Vang field, due to come on stream later this year.

Wood Mackenzie expects HSV to be developed as a standalone project using an FPSO linked to wellhead platforms. Murphy, which plans two additional appraisal wells through 2026 to further delineate the resource, has now discovered over 1.4 billion boe of net resources in its Southeast Asia portfolio since 2002.

While Banyu Urip was discovered onshore Indonesia in 2001, the region enlarged its arsenal further after Gumusut followed suit in 2023 in the deep waters of Malaysia. Murphy was involved in the development of the latter, enabling the firm to get a track record in Southeast Asia’s most recent big oil finds.

Angus Rodger, Head of Asia-Pacific upstream analysis for Wood Mackenzie, commented: “In a predominantly gas-prone region, oil discoveries of this scale are exceptional. HSV ranks as the third-largest oil discovery in Southeast Asia since 2000, trailing only Indonesia’s Banyu Urip and Malaysia’s Gumusut. Remarkably, Murphy has made two of the five largest oil finds since 2000 and was involved in the development of a third.”

While Wood Mackenzie sees HSV as the latest success in Southeast Asia’s exploration renaissance and deems it to be great news for oil-focused exploration in the region, the firm also identifies other high-impact wells still to come in 2026, pinpointing three Asia-Pacific wells-to-watch over the next 12 months that are targeting material liquids targets.

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The list of these wells entails TotalEnergies‘ ultra-deepwater Maliu-1 in Papua New Guinea, which is targeting 500+ mmboe, Jampuk-1 in the ultra-deepwater of Malaysian Sabah, and Pertamina‘s Besar-1 offshore Indonesia with 450 mmboe target.

Rodger added: “Southeast Asia is proving that mature basins still hold significant potential when paired with modern exploration techniques and improved fiscal terms. The challenge now is converting these discoveries into production that will require sustained commitment from both governments and operators.”