While the Shelf Perseverance jack-up drilling rig created the Blythe H2, the newly spudded well experienced ‘fluid losses’.
The UK-based gas and infrastructure operator, IOG, said that “an abnormally pressured gas and oil influx was encountered” while drilling through the Hauptdolomit formation within the Zechstein, which resulted in “associated drilling fluid losses.”
This is expected to impact well duration by up to four weeks associated cost impact will depend largely on “the speed of resolution”, IOG (LON: IOG) writes.
Located in the Southern North Sea, the Blythe H2 well has been described as “lower risk” than IOG’s Southwark and Saturn Banks projects.
Chief executive of IOG, Rupert Newall, said: “Encountering a gas and oil influx while drilling through the overburden above the reservoir is a known risk in the Southern North Sea.
“Associated drilling fluid losses present an additional challenge, however this is being actively and safely managed by Petrofac, the Well Operator, and Shelf, the drilling contractor, working closely with the IOG team, to ensure that drilling ahead can be safely resumed.”
The influx has been determined to contain non-commercial quantities of oil and gas and is not related to the target Rotliegendes gas reservoir which is over 500 ft deeper and isolated from the Hauptdolomit.
The well has been displaced to a mud weight above the formation pressure. Options to progress include isolation of the influx zone with cement and, if necessary, side tracking of the well.