Sean gas field

The Sean gas field is a small natural gas and associated condensate field located in the UK sector of the North Sea, 67 miles off the Norfolk coast.

The field
The Sean gas field is a natural gas field located in the North Sea and comprises three accumulations North Sean, South Sean and East Sean. The field 67 miles north-east of Bacton Norfolk and is located to the south east of the Indefatigable gas field. It is named after the four partners at the time of its discovery: Shell, Esso, Allied Chemical and National Coal Board. The gas reservoir is a Rotliegendes sandstone 170–290 feet (52–88 metres) thick at a depth of 8,300 feet (2,530 m). North Sean was discovered in April 1969 and South Sean in January 1970 both are located in UK Block 49/25. The original determination of the gas in place amounted to 425 billion cubic feet (12.4 billion cubic metres).

Development
The Sean field has been developed through a number of offshore platforms. The East Sean field has not been developed.

Production
Production from the field began in August 1986. Sean was operated as a peak shaving field with a maximum delivery of 600 MMSCFD (million standard cubic feet per day). Processing facilities comprise 3-phase separation and gas dehydration. Gas and associated condensate are transported via a 30-inch diameter pipeline to the Shell processing facility at the Bacton gas terminal, Norfolk.

The specification of third party gas for entry into the export gas pipeline was as follows: In June 2015 Oranje-Nassau Energie (ONE) acquired a 50% interest in the Sean field from Shell. SSE E&P UK holds the remaining 50% interest. ONE became the operator of Sean.