The Snoek-1 well was drilled to a depth of 5,175 m (16,978 ft) in 1,563 m (5,128 ft) of water. It encountered 25 m (82 ft) of oil-bearing sandstones of Maastrichtian-Aptian age, similar to the Liza-1 discovery well 9 km (5.6 mi) to the north.
Next the rig will drill the Liza-4 appraisal well. ExxonMobil’s partners are Hess and CNOOC subsidiary Nexen.
The discovery follows ExxonMobil’s recent Payara find and Liza-3’s uncovering of a new reservoir on the same block.
Wood Mackenzie says its base case for Liza-Payara is 1.5 Bbbl of oil, while Snoek may add a further 220-370 MMbbl. The partners have also identified five more prospects on the block that they plan to drill through 2018.
In addition, ExxonMobil farmed into and took operatorship of two blocks north of Stabroek, while Hess farmed into block 42 off Suriname.
Apache is currently drilling the Kolibri-1 well on Suriname’s block 53, while Tullow will drill on block 54 later this year.
According to the analyst, a key unknown is whether the Cretaceous fan play extends across the Guyana basin or is isolated to this discovery cluster.
The three Stabroek discoveries are within 30 km (18.6 mi) of each other, so economies of scale could be achieved if associated FPSOs and subsea infrastructure were shared.
However, with each new find disposal of associated gas (the analyst estimates more than 3 tcf so far) becomes a bigger challenge. Initially, the joint venture plans to target low-GOR (gas-oil ratio) areas and will re-inject produced gas, but FLNG or a long pipeline may be needed as well.
The partners are taking a phased approach to the area’s development. Wood Mackenzie anticipates two large FPSOs to develop Liza and Payara and a further vessel for Snoek.
It has drawn up two scenarios for Snoek: a high case with reserves of 370 MMbbl produced through a 120,000-b/d FPSO, and a base case of 220 MMbbl with an 80,000 b/d-FPSO.
The resultant developments could lead to Guyanese production peaking at 400-450,000 b/d during the next decade.
Guyana’s fiscal terms were set at a level to attract high-risk frontier wells, the analyst points out. But success could bring a tightening of these terms as the country’s expectations shift.