Amethyst East

Location

The Amethyst gas field is situated approximately 30 miles (48 km) east of the Yorkshire coast in the Southern North Sea.

Geology

The gas in the Amethyst field is trapped in a Permian sandstone reservoir, which is located around 2,700 metres (8,900 ft) below the seabed.

History

• The Amethyst gas field was discovered in 1972 and named after HMS Amethyst.
• Between 1972 and 1985, several appraisal wells were drilled to assess the field.
• Field development began in 1988, and the first gas production started in 1991.
• Initially, the field was owned by multiple companies including BP, Enterprise Oil, British Gas, ARCO, Murphy Oil, Amerada Hess, and FINA. In 1997, BP acquired Enterprise Oil's interest and became the largest stakeholder. Following several transactions, the ownership was later held by BP (59.5%), BG (24.15%), Centrica (8.95%), and Murphy Oil (7.4%). In December 2009, BP took over BG's interest in the field.

Operations

• The field is operated using four small unmanned steel satellite wellhead platforms: A1D, A2D, B1D, and C1D.
  • A1D and A2D platforms were built in 1989 and have 5 and 6 wells respectively in Amethyst East.
  • B1D and C1D were built in the following years and produce from 4 and 7 wells in Amethyst East and Amethyst West respectively.
  • C1D is connected to A1D, and B1D is connected to A2D.

Production

• Daily operations and processing are carried out onshore, with personnel only visiting the platforms for maintenance and well work.
• Produced gas is transported to the Easington Gas Terminal and sold to Électricité de France.
• By the end of 2014, Amethyst East had delivered 15,778 million cubic meters (mcm) of gas since 1990.

Associated Fields

• The Helvellyn gas field, discovered in 1985, was developed as a subsea wellhead in 2004 with production routed to the Amethyst A2D platform.
• The Rose gas field, comprising a single subsea well, was tied back to the Amethyst A2D platform via a pipeline and was in operation from 2004 until its closure in 2015.

Safety and Incidents

• In September 2007, three crew members of the emergency response and rescue vessel Viking Islay were killed during a support operation on the Amethyst gas field.

Decommissioning

• In 2012, the field operatorship was transferred from BP to Perenco.
• Due to high operational costs and reduced gas production, Perenco concluded that continued operations were uneconomical.
• In July 2020, Perenco received approval for its draft decommissioning programs for the four Amethyst gas field topsides from the UK authorities. The topside removal for C1D, B1D, and A1D installations is expected between Q4 2023 and Q1 2024, with A2D following in the third quarter of 2024.