HSV-2X oil field could be Vietnam's largest crude oil discovery

Before the new announcement about the Hai-Su-Vang (HSV-2X) oil field, the Bach Ho oil field was recognized as Vietnam’s largest oil field. According to PetroTimes, it is one of the world’s exceptional fields with very large reserves—over 500 million tonnes of oil and gas in place—operated by Vietsovpetro, with production around 12 million tonnes per year from a reservoir located in the Mesozoi granitoid basement in the Late Tertiary sedimentary basins.

Bach Ho: Vietnam’s former benchmark field

Bach Ho was discovered and began production on September 6, 1988. Oil shows in the basement rock were recorded in well BH-1, but reservoir testing did not yield oil. The BH-6 well drilled to a basement depth of 23 m to a depth of 3,533 m, and on May 5, 1987, when testing the reservoir together with the Oligocene layer, yielded a flow of 477 tonnes per day.

Oil in fractured basement rocks was confirmed to have industrial flow when the reservoir was re-tested in BH-1 and was put into production on September 6, 1988. The field is described as a large oil body in fractured and cavernous granitoid rock, with proven oil in place over 500 million tonnes. The field area is nearly 60 km², and the oil column height is measured at 1,300 m. Peak production exceeded 12 million tonnes per year, with initial well flow potentially reaching up to 2,000 tonnes per day.

New announcement: Hai-Su-Vang (HSV-2X) in Block 15-2

In the IV/2025 quarterly briefing on the morning of January 29, 2026, the Ministry of Industry and Trade announced information about oil discovered at Hai-Su-Vang (HSV-2X) in Block 15-2, within the Cuu Long basin.

Murphy Oil of the United States has participated in search, exploration, and oil activities in Blocks 144-145 and 15-1, 15-2. Exploitation, exploration, and search activities in recent years have yielded positive results. For the discovered oil reserves at Block 15-2—the Tiger Gold (Hai-Su-Vang) field—Murphy Oil’s subsidiary is currently the operator.

Exploration and appraisal results

In 2024, Murphy Oil began drilling exploration wells at Hai-Su-Vang. In 2025, an appraisal well (drilled after discovery) was successfully completed to assess scale, reserves, and producibility. Based on the discovered results, Hai-Su-Vang is judged to have strong potential.

Previously, from Q4/2024, the company started drilling exploration wells at Hai-Su-Vang-1X. In January 2025, it discovered about 370 feet (112 m) of oil from two pay zones.

The recent appraisal well, Hai-Su-Vang-2X, shows total reservoir thickness reaching 131 m, concentrated in the deeper main reservoir. Reported flow is about 6,000 barrels per day, with high-quality oil at 37 API. The field’s reserves are estimated at roughly 170-430 million barrels of oil equivalent, potentially exceeding 430 million barrels.

Analyst view: potential scale in Southeast Asia

According to Wood Mackenzie, a UK-based energy and natural resources analytics firm, given the current scale, Hai-Su-Vang could be the third-largest oil discovery in Southeast Asia since 2000, behind Indonesia’s Banyu Urip (2001) and Malaysia’s Gumusut (2003).

Wood Mackenzie also said this could be the region’s largest discovery in the last 20 years if subsequent appraisal results continue to support the reserves.

Impact for Vietnam’s oil output

Wood Mackenzie’s assessment suggests the discovery could help Vietnam reverse a long-standing decline in oil output. Vietnam’s crude oil production fell from about 365,000 barrels per day in 2005 to below 120,000 barrels per day in 2025.