Commercial offshore diving

Commercial offshore diving, sometimes shortened to just offshore diving, is a branch of commercial diving, with divers working in support of the exploration and production sector of the oil and gas industry in places such as the Gulf of Mexico in the United States, the North Sea in the United Kingdom and Norway, and along the coast of Brazil. The work in this area of the industry includes maintenance of oil platforms and the building of underwater structures. In this context "offshore" implies that the diving work is done outside of national boundaries.

Equipment used for offshore diving tends to be surface supplied equipment but this varies according to the work and location. For instance, divers in the Gulf of Mexico may use wetsuits whilst North Sea divers need dry suits or even hot water suits because of the low temperature of the water.

Diving work in support of the offshore oil and gas industries is usually contract based.

Saturation diving is standard practice for bottom work at many of the deeper offshore sites, and allows more effective use of the diver's time while reducing the risk of decompression sickness. Surface oriented air diving is more usual in shallower water.

The offshore diver may do a wide range of tasks in support of offshore drilling or production.

Much of the offshore seabed diving work is inspection, maintenance and repair of the blow-out preventers (BOPs) and their permanent guide bases. The primary functions of a blow-out preventer system are to confine well fluid to the wellbore, provide a way to add fluid to the wellbore and to allow controlled volumes of fluid to be withdrawn from the wellbore. Dive work includes assistance with guiding the blowout preventer stack (BOP stack) onto the guide base, inspection of the BOP stack, checking connections, troubleshooting malfunctions of the hydraulic, mechanical and electrical systems, and inspection of the rig's anchors.

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