UK-listed Serica Energy has begun development drilling at the Columbus field in the UK central North Sea.

The Columbus23/16f-CDev1 — the only planned production well — is being drilled by the heavy-duty jack-up Maersk Resilient to a total depth of 17,600 feet and will include a 5600-foot horizontal section, Serica said on Wednesday.

Work is expected to take about 70 days.

Columbus will be tied back to the Shell-operated Shearwater production facilities about 35 kilomtres away via the Arran-to-Shearwater pipeline.

The field's undeveloped proven and probable reserves are believed to be in excess of 14 million barrels of oil equivalent.

Production is expected to start early in the fourth quarter at rates of about 7000 barrels of oil equivalent per day, of which over 70% is gas.

Serica is operator on a 50% interest with partners Waldorf Production on 25% and Tailwind Energy on 25%.

Serica chief executive Mitch Flegg said: “I am delighted that drilling operations have commenced on the development well, which is a significant milestone for the company as Columbus is the first development project that Serica has undertaken as operator in the North Sea."

Columbus was earmarked for development in the past as a tie-back to the nearby Lomond facilities but Serica's attempts were thwarted by a series of changes in ownership at Lomond, first from BP to BG Group in 2009, then from BG to Shell in 2015.

Elsewhere, intervention work to reinstate the R3 well at Serica's Rhum gas field is "progressing towards completion", Serica said in the update.

Next year the company is planning an exploration well on the North Eigg prospect.