Murphy Oil’s Hai Su Vang (Golden Sea Lion) appraisal well offshore Vietnam confirmed the 2025 discovery as “significant,” and further appraisal wells are slated for later this year.
On 6 January, Murphy said its appraisal well in Block 15-2/17 in the Cuu Long Basin had encountered 429 ft of net oil pay across the same two reservoirs as the 2025 discovery, which was drilled in 149-ft water depth and found 370 ft of net oil pay. The appraisal well, spudded in October 2025, found 332 ft of pay in the deeper primary reservoir and 97 ft in the shallow reservoir.
Murphy President and CEO Eric Hambly said in a news release that the significant discovery represents a pivotal moment for the company’s Vietnam business.
“The success of HSV-2X not only reinforces the commerciality of the Hai Su Vang field but also sets the stage for a robust development program,” he said.
The appraisal well flowed at 6,000 BOPD of 37 °API oil from the primary reservoir, with further testing ongoing.
The appraisal well extended the total hydrocarbon column to about 1,600 ft, and formation evaluation supports reservoir continuity to the discovery well, Murphy said. The operator has also updated its range of recoverable resources from the primary reservoir, saying the new midpoint is “towards the high end of our previously communicated range of 170 to 430 million BOE, and the high end of the new range now exceeds 430 million BOE.” Murphy added that the shallow reservoir provides recoverable upside that it had not included in its previously announced range. Further appraisal wells are needed, Murphy said, to refine the range of recoverable resources for both reservoirs.
Murphy is planning a delineation campaign that includes evaluating additional reservoir intervals with the HSV-3X appraisal well located in Block 15-1/05 and the HSV-4X well in Block 15-2/17, which are included in the company’s 2026 capital program.
Murphy subsidiary Murphy Cuu Long Tay Oil Co. Ltd. operates Block 15-2/17 with 40% working interest on behalf of partners PetroVietnam Exploration Production Corporation Ltd. with 35% interest and SK Earthon Co. Ltd. with 25% interest
Murphy subsidiary Murphy Cuu Long Bac Oil Co. Ltd. operates Block 15-1/05 with 40% working interest on behalf of partners PetroVietnam Exploration Production Corporation Ltd. with 35% interest and SK Earthon Co. Ltd. with 25% interest.