Asset and Opportunity

Enneco currently holds the Licence P.2370 in the UK North Sea in Block 16/3e. The Block lies in about 110m of water, close to the northern part of the Brae field complex. Significantly, the Block contains the Shelterstone discovery initially found by the 16/3a-E22z well drilled by Marathon from the East Brae platform in 1997.

Well 16/3a-E22z

16/3a-E22z well unexpectedly encountered, and subsequently flowed at a good rate from a 16 foot interval in moderate quality sand in the overlying lower Cretaceous Skiff (Cromer Knoll aged). Oil has also been encountered in the Lower Cretaceous Skiff sands in the nearby 16/3a-E22 and 16/3a E16 wells which collectively can now be shown to have penetrated a hydrocarbon column with a free water level at -4,046m TVD sub-sea.

New 3D Mapping

New 3D seismic has been key to unlocking the significance of these well results as the interpretation now shows they have tested the southern and peripheral part of a potentially large N-S orientated stratigraphic trap against the Viking Graben margin. The planned appraisal well location is expected to encounter 150ft of good quality Skiff sands proving the Shelterstone Discovery to be economic in all development scenarios.

Recoverable Reserves

The new mapping shows the Skiff sand unit thickens to the north with the ‘most likely’ resource potential of the Shelterstone trap is currently estimated to be 115 MMbbls recoverable based on conservative criteria. The closure could contain several hundred million bbls if the Skiff sands are encountered up dip with reservoir quality approaching the 25% porosity and 400+ mD permeability seen in the best core data from the 16/3d-13 well.

Farmout Process and Development Options

Enneco is actively seeking a partner to join them for a working interest in Licence P2370 and accelerate the appraisal and expected exploitation of the Shelterstone discovery.  A significant equity position and operatorship is available for an existing UKCS operator or experienced international operator who can satisfy the main work obligation – by committing to an appraisal well to be drilled on Shelterstone.  A vertical well is planned to penetrate the sweet spot of the up-dip crest of the mapped closure with the aim of confirming well productivity and oil and gas potential.


Development options are FPSO, or potentially the nearby East Brae infrastructure which would allow a short project cycle, quick return on investment and increased knowledge of the reservoir.