The well was drilled to a total depth of 4,927 m in 1,427 m of water, with preliminary analysis indicating 29 m of net oil-bearing reservoir in Cretaceous sandstones. No water contact was encountered in a gross oil-bearing interval of more than 500 m.
Gravity oil of 28° to 41° was indicated from several recovered samples. Cairn says further evaluation will be required to calibrate the well with existing 3D seismic to determine future plans as well as optimal follow up locations to determine the extent of the discovered resource.
“We have encountered a very substantial oil-bearing interval which may have significant potential as a standalone discovery,” said Simon Thomson, Cairn chief executive officer. “Furthermore, this result materially upgrades the prospectivity of the block with a proven petroleum system and a number of deep fan and shelf prospects established.
“Work is already under way with the joint-venture partners to determine follow up activity, which is targeted for 2015 onwards,” Thomson added.
Following completion of operations at FAN-1, Transocean Inc.’s Cajun Express semisubmersible drilling rig will move to the SNE-1 well, also on the Sangomar Deep block, where it will target a dual objective in 1,100 m of water (OGJ Online, Mar. 19, 2014).
The top hole has been drilled pending reentry. Partner FAR Ltd. has estimated the two prospects to hold a combined 1.5 billion bbl of oil.
Cairn operates the Sangomar Deep, Sangomar Offshore, and Rusifique blocks offshore Senegal with 40% working interest. ConocoPhillips holds 35%, FAR Ltd. 15%, and Petrosen 10% (OGJ Online, Aug. 1, 2013; Feb. 12, 2014).