Offshore staff
LONDON – IOG’s latest development well in the Saturn Banks area of the UK southern North Sea has been impacted by an abnormally pressured oil and gas influx, with associated drilling fluid losses.
The Shelf Drilling Perseverance jackup spud the H2 well, operated by Petrofac, on the Blythe gas field on March 5. Operations were expected to last about three months, including completion and hookup.
However, on entering the Hauptdolomit Formation within the Zechstein sequence, the well experienced the influx. While Petrofac, Shelf and IOG are managing the well control issue, drilling will likely be extended by a further four weeks, depending on the speed of resolution.
The influx from the Hauptdolomit contains non-commercial quantities of oil and gas but is not related to the target Rotliegendes gas reservoir, which is more than 500 ft deeper and isolated from the Hauptdolomit.
The well has been displaced to a mud weight above the formation pressure, IOG added. Options going forward include isolating the influx zone with cement and, if necessary, drilling a sidetrack.
Rupert Newall, the company’s CEO, said encountering an influx while drilling through the overburden above the reservoir is a known risk in the region.
04.18.2023
