It does not happen very often that Shell drills an exploration well in Norwegian waters. And even though the well name does sound more like a development hole, 6305/5-C-3 H is a genuine exploration attempt. It is not what you would call frontier exploration though, as the well is testing prospectivity beneath the Upper Cretaceous and Paleocene (Danian) reservoirs of the Shell-operated Ormen Lange field.
The well is part of an extensive drilling programme Shell has now embarked on. Besides the currently drilling exploration well, Shell will also be drilling two additional development wells on the field itself: 6305/5-C-3 AH and 6305/7-D-4. The first of those will be a side track from the exploration well mentioned above.
The target of the exploration sounds as a familiar one for the Norwegian Sea; the Cretaceous sandstones of the Lysing and Lange formations at around 3750 m and 4150 m depth respectively. With the top of the Paleocene Egga Formation reservoir of Ormen Lange being situated at a depth of approximately 2,700 m, it means that the Lysing reservoir is expected to be approximately 1000 m deeper.
In a geographical sense, Ormen Lange is a particular field as it is giant (initial reserves amounted to 2,300 MMboe) but relatively isolated with respect to the other Norwegian Sea fields. The field is also situated in the scar of the Holocene Storegga slide, which is the last of a series of major slides in the area that happened over the past 500,000 years. The sandstones of the Ormen Lange reservoirs are turbidite sands shed from the mainland to the east, which probably also applies to the targeted Lysing and Lange formation sands.
The licence situation in the area is not straightforward. Whilst Shell operates the Ormen Lange field at 17.8%, Equinor owns the biggest stake in the field with at 25%. In turn, the exploration well is officially drilled in licence PL209, which is operated by Equinor at 40% with Shell only having a 15% stake. In that sense, whilst Shell is the operator of the well, the stakes for the company are relatively small.
HENK KOMBRINK
