Offshore Oil Production

Initially, near-shore oil was produced from booms located as a direct extension of onshore fields. As prospecting techniques developed, it became possible to explore and exploit increasingly deeper offshore deposits. Over the past ten years, new methods for acquiring and analyzing seismic data at sea have made it possible to identify potential reservoirs not only at great water depths, but also beyond, through 6 to 8 km of marine sediments, including thick layers of salt. The concomitant progress in drilling allows access to water depths of 3.7 km.

The beginnings of the offshore industry date back to October 1947, when the US company Kerr-McGee installed the first platform in the Gulf of Mexico (Ship Shoal block 32) out of sight of the coast at a depth of 6.7 m, 30 km off the coast of Louisiana. By way of comparison, in 2015, Total brought the CLOV field in Angola on stream in 1,400 m of water, and Petrobras brought the Guara Sapinhoa field in Brazil on stream in 2,400 m of water. Shell has since brought the Stones field (Walker Ridge block 508) on stream in September 2016 in water depths of 2,900 m, 320 km offshore Louisiana.

According to a 2010 IFPEN estimate, offshore oil and gas accounts for 20% of the world's reserves. Between 2005 and 2015, offshore oil production remained constant at just under 30 million barrels per day (NYSVEEN, 2015), despite significant investment until 2014.

Whether offshore or onshore, production from a given oil field declines by around 10% a year if nothing is done to assist it. It is necessary to make new discoveries all the time, if only to keep production constant. A slowdown in investment therefore has a direct impact on production in the medium term. In the case of shale oil (also known as bedrock hydrocarbons), the annual decline is greater, of the order of 40-50%.

Offshore production areas are widely dispersed: mainly the North Sea, the Gulf of Mexico, the Gulf of Guinea, Brazil, the Arabian Gulf and the Far East (Australia, China, Indonesia, Malaysia), but also many other regions.

Offshore oil production units have evolved rapidly, and with them their manufacturing and installation resources.

These units cover a wide range of issues:

• the importance of safety and the environment, under the watchful eye of public opinion;

• the geographical dispersion of sites and the difficulty of maintaining logistics and resources ;

• cost-cutting, particularly topical with the fall in prices;

• competition with other forms of production, and in particular with onshore production of bedrock hydrocarbons...