Originally planned to be drilled last year, well 22/01b-12, operated by Ithaca Energy and partnered by Spirit (40%), must probably be seen as an example of a Covid-related deferral.
Spudded only a few days ago, it targets gas in remobilised sands of the Eocene Caran Fm, which also form the principal reservoir in the nearby Ithaca-operated Alba oil field. This is only the second exploration well spudded on the UKCS this year, with Equinor now supposedly having completed drilling the Tiger Lily prospect with 16/02a-6.
If successful, a gas discovery with 22/01b-12 can potentially be tied-back to the Alba field and from there to the Britannia gas/condensate field, which is operated by Chrysaor and partnered by Ithaca at 32%.
Chestnut
Licence P2373 partner Spirit Energy has got plenty of experience drilling targets such as Fotla, gained through operating the Chestnut field a little bit further to the east. Chestnut is a sand-injectite field of which the sands may originally have been deposited as a terminal lobe fan of the Eocene sands in the Alba field. However, subsequent remobilisation has significantly complicated reservoir architecture, demanding close monitoring of development well drilling.
Despite its complex reservoir architecture of thin and difficult to map sandstones, Chestnut has so far produced about four times as much oil as originally thought (7 MMboe at field sanction). For that reason, Ithaca may have been pushed over the edge to drill Fotla and with gas expected in this prospect, drainage may be a little easier than in Chestnut.
More prospects
A little further to the north, more prospects have been mapped close to and within P2373, labelled 1, 2, 3 and 4 on the map above. Prospect 1 was originally named as Langley by Sussex Energy in 2011 and was identified in Paleocene Andrew deep water sandstones as a combined dip and stratigraphic closure. With a mean estimated reserve of 36 MMboe, Langley may represent the second target in the licence (Fortriu) mentioned by Ithaca, but this cannot be confirmed. Sussex Energy relinquished its licence (P1417) over Langley in 2011 as it could not lower the risk associated with drilling Langley.
The other prospects mapped are only partly (4) or not (2, 3) situated in P2373 and formed part of licence P2181 relinquished by Centrica in 2017. Prospects 2 and 3 are small Eocene injectite targets of the same nature as Chestnut, named Pinenut and Walnut respectively. Only Walnut was risked by operator Centrica and was deemed too small (GIIP of 3.8 MMboe) to drill. Prospect number four represents an Upper Jurassic target named Ifield, with an estimated reserve of 68 MMboe. Although a well was drilled within its perimeter, it terminated in the Eocene, leaving the Upper Jurassic untested.
HENK KOMBRINK
For illustration purposes, only gas pipelines are shown in the map above.
