Completing a long horizontal producer (5,900 ft) on the Columbus field with sand screens has turned out to be more difficult than foreseen, leading the operator Serica Energy to drill a side-track. The reservoir consists of fairly unconsolidated Eocene-Paleocene Forties sands and shales, which do need sand screens in order to mitigate against sand production issues.
The company has now chosen to drill a side-track and re-drill the entire reservoir section, learning from the previously drilled interval to optimise its trajectory. The well, 21/16f-C1, is drilled from a surface location in the centre of the field. Its total measured depth was 17,600 ft.
The additional operations are expected to take around three to four additional weeks, but the operations are not expected to impact the timing of production start-up, which is still expected during Q4 2021.
Upon completion of the 21/16f-C1 well, it will be connected to the Arran pipeline from where the hydrocarbons will be piped towards the Shearwater platform where the gas and condensate will be separated.
Serica Energy and partners Waldorf (25%) and Tailwind (25%) expect an average gross production from Columbus of around 7,000 boe/d. The accumulation is expected to hold 14 MMboe.