Ten years ago it was not difficult to bring to mind many of the floating oil and gas production systems operating in the world. But this has changed as these systems have grown in number.
The International Maritime Associates Inc. July 2005 worldwide survey found 176 floaters in operation, about triple the number operating 10 years ago. And the numbers keep growing, with 34 more on order.
The July 2005 report was IMA’s 25th in a series that began in 1996.
Floating production systems include tension-leg platforms (TLPs); semisubmersible vessels; floating production, storage, and offloading (FPSO) vessels; spars; and floating storage, and offloading (FSO) vessels.
IMA says the industry has placed contracts for 12 new floaters since the beginning of 2005. Asian builders have contracts on 40% of these orders.
IMA also expects that 93 planned projects will require floaters and reckons that one third of these projects are in the final design or bidding stage.
In the next 5 years, it sees the industry needing 82-104 new floaters and spending $25-33 billion to build them. Of the future orders, IMA expects FPSOs to account for 70% and spars, TLPs, and semis to make up the remaining 30%.
Deep water
Development of oil and gas fields in increasing water depths is the obvious reason for the growing need for floaters. Even in deep water, however, long tie-backs provide an alternative.
Deep water in the Gulf of Mexico has seen several long tie-backs from subsea wells to conventional fixed, shallow-water platforms. The schemes eliminate the need for floating production units on subsea developments. The longest tie-backs usually are for gas fields, and some subsea developments tie back to floating units.
In the gulf, floaters are either TLPs or semis; to date, no company has installed an FPSO in US gulf waters. There are two FSOs off Mexico and one FSO in the Caribbean off Colombia.
Norwegian waters also have developments that eliminate floating units. Statoil ASA’s Snøhvit field will be the first major development on the Norwegian continental shelf with no fixed or floating units. The Barents Sea development will be in 250-345 m of water and produce gas from wells in Snøhvit, Askeladd, and Albatross fields through a 145-km pipeline to shore.
Orman Lange gas field, operated by Norsk Hydro ASA during the development phase and Norske Shell AS during the production phase, is the next major Norwegian field in which production will move directly to shore from subsea wells. Orman Lange production will flow from wells in 800-1,000 m water through two 30-in., 120-km pipelines to shore. Hydro expects production to start in October 2007.
The BG Group off Egypt also uses long tie-backs to eliminate the need for floating units. Its first two gas fields, Simian and Sienna, in deep water in the West Delta Deep Marine concession about 120 km off Alexandria in the Mediterranean Sea, tie into a shallow-water control platform before the gas goes ashore.
Outside of these gas developments, most future deepwater fields will depend on floating production units.
New floater locations
IMA’s report shows that of the 34 floating production units on order that have been assigned, 8 are for West Africa, 9 for Brazil, 7 for the Gulf of Mexico, 3 for Southeast Asia, 3 for Europe, and 1 each for Australia, China, and Canada.
The 34 units include 3 TLPs, 22 FPSOs (13 new, 9 conversions), 6 production semis, and 3 spars.
Of the 97 projects in the bidding stage, IMA expects 2 projects may include LPG FPOs. West Africa leads in the number of units with a possible need for 27 floaters.
IMA’s analysis documents the movement of floaters into increasing water depths. Of the floaters currently operating, only 15% are in more than 1,000 m of water, while 68% of the floaters on order will be in water deeper than that. Of the planned floaters, an expected 56% will be in more than 1,000 m of water.✦
