Wellesley reports successful appraisal of Grosbeak discovery
STAVANGER -- Wellesley Petroleum AS, the exploration company focused on the Norwegian Continental Shelf (NCS) announces the successful appraisal of the Grosbeak Discovery in the Northern North Sea by wells 35/11-21S and 35/11-21A. The wells were drilled in production license Pl248I, where Wellesley holds a 60% operated interest.
Well 35/11-21S encountered a gross oil column of 90 m at the target Middle Jurassic Brent Group level. Within this oil column, 46 m comprised net reservoir with generally excellent reservoir properties. Extensive data was acquired from the reservoir interval, including a successful well test that confirmed the high quality and good connectivity of the reservoir.
Sidetrack well 35/11-21A encountered 18 m of excellent quality gas-bearing reservoir and an eight-metre oil column in the shallower Upper Jurassic Songenfjord and Fensfjord formations. The underlying Brent Group reservoir comprised nine metres of oil-bearing sandstones above the oil water contact. Pressure data from these sandstones demonstrates good connectivity to the zone tested in the 35/11-21S well.
The updated range of recoverable resources in the Grosbeak Discovery is 53-115 MMbbl of oil plus 269-432 Bcf of gas. The 35/11-21S and A wells will now be plugged and abandoned and development studies will commence.
Chris Elliott, CEO of the Wellesley Group of companies, commented “This is a very pleasing end to our operated drilling campaign in the Grosbeak area.
“Our pre-drill subsurface studies of Grosbeak indicated that the Brent Group sandstones were predictable and well-connected, and this has been demonstrated by the appraisal wells, significantly reducing the development risk of this reservoir.
“The discovery of a separate, excellent quality gas reservoir in the Upper Jurassic also adds significant resources to what we expect to be a material and commercially robust future development.
“It is particularly pleasing to have reached this point just 10 months after assuming operatorship of the PL248I license. These wells conclude an operated 159-day summer drilling campaign with almost 13,000 m drilled in five boreholes and extensive data collected from each of the five hydrocarbon-bearing zones encountered.
“Drilling efficiency has been outstanding and was undertaken with excellent focus on risk management and major accident prevention. We extend our gratitude to our licence partners, our network of suppliers and the relevant authorities for their support in the planning and delivery of this well program.”
