Photographer: Simon Dawson/Bloomberg Photographer: Simon Dawson/Bloomberg Aboard a Rig That Helps Power Britain After decades of production, North Sea oil and gas yields are in long-term decline. Low crude prices complicate the decision about investing billions to reverse the output trend. BG Group Plc, owner of the Armada gas field, has found an elegant exit: an $51 billion sale of the company to Royal Dutch Shell Plc. Its predecessor was privatized by the British government in 1986 as British Gas Plc. Eleven years later, the corporation split, with Centrica Plc taking the British Gas division that supplies consumers, while BG kept the oil-drilling unit. See how they keep the barrels pumping. Photographs by Simon Dawson for Bloomberg By Timothy Coulter @TimothyCoulter2 More stories by Timothy Coulter and Tom Hall @pixhallphotos More stories by Tom Hall December 22, 2015, 12:01 AM EST The Armada gas platform produces from a group of reservoirs across more than 31 square kilometers (12 square miles) in the central North Sea. It's a helicopter ride to get there. Offshore workers exit a Bristow AS332 Super Puma as they arrive on the platform, which is located northeast of the Scottish energy hub of Aberdeen. A crane moves cargo on the weather deck, the large grey accommodation modules can be seen at the rear. A firefighter's helmet reflects a gas flare as he stands on the helicopter deck. When working on platforms in the North Sea, you're often far from civilization - the Armada platform is 250 kms (155 miles) from shore. An employee walks down stairs in view of a flare that burns excess gas. Safety helmets aboard the platform. The fields - Fleming, Drake, Hawkins and Seymore - that the Armada platform services are named after sailors who fought and defeated the Spanish Armada in 1588. A chemist prepares a pipe so she can mix chemicals on the well deck. A worker testing the level of gas condensates in a water sample. An engineer checks valves and pipes on deck. Production on the Armada block began in 1997. Survival suits are worn when in transit but sit folded up when not in use. The platform serves a group of natural gas fields in the centre of the North Sea. Syringes used to test samples of gas condensate sit in a laboratory. A worker speaks on the phone as he monitors computers in the control room. Safety is paramount. A supply of warning signs sit attached to a board on the wall of the control room. Workers play snooker during down time. Personnel are aboard the platform on a work pattern that lasts up to two weeks. One of the sleeping cabins. The living facilities on the platform can accommodate more than 50 people. The escape route, if ever needed, leads straight to the sea - where rescue vessels may approach.