PetroTal commenced drilling Well 20H at the Bretaña field on July 26, 2024. The 20H well has allowed for the evaluation and testing of the upper Vivian formation sand (VS1), which for the first time will be jointly completed with the main Vivian 2 (VS2) sand.
For background, the Vivian formation at Bretaña consists of two primary sand bodies. So far, PetroTal has only produced from the VS2 sand, where permeability is an order of magnitude greater than the VS1 sand. As of year-end 2023, Netherland, Sewell and Associates, Inc. estimated that about 20% of the 442 million barrels of 2P original oil in place at the Bretaña field is assigned to VS1, while all 2P reserves are allocated to VS2.
The 20H well design included a short test of the VS1, to acquire crude samples and test production deliverability. During a brief production test, the VS1 flowed at an equivalent rate of approximately 320 barrels of oil per day of 18.6 API oil, which is of similar gravity to the VS2 oil.
PetroTal has decided to complete the 20H well in both sands. Once sufficient production data has been collected, the company will evaluate the possibility of amending its field development plan to include the VS1, with a view to potentially including the unit in Bretaña’s future 2P oil reserves certification. If expectations of low production of formation water volumes from the VS1 are confirmed, oil produced from the VS1 conceptually should not require additional water treatment facilities to be constructed.（2024-09-04）