Siemens to produce first subsea power grid by June 2016
Siemens is planning to bring to market the first complete electrical power solution for subsea factories by June 2016, Are Dahl, Director of Siemens’ oil and gas subsea solutions division told Upstream Intelligence.
Siemens expects the subsea grid to be the world’s first complete solution to power the various factory components, which include compressors, pumps and subsea separation units.
Siemens is developing the grid with a group of partners, led by Chevron and including Statoil, Exxon and Petrobras, as part of a $100m Joint Industry Program (JIP) to develop a complete subsea power network.
Subsea processing has until now been powered by fixed platforms but operators are looking to lower the costs associated with manned facilities while exploring deeper fields.
Dahl told Upstream Intelligence that Siemens and its partners are discussing whether to launch the product in February or June next year. This will depend on whether there is sufficient supply of components for the Variable Speed Drive (VSD), he said.
The electrification of a subsea factory involves three essential pieces of equipment: transformers, switchgear and VSDs. The main difficulty faced by electrical contractors has been to design and manufacture a VSD that could operate at 300 bars of pressure for a minimum of 30 years.
“It’s the VSD that is the problem and that’s no big shock because it’s the most complicated part of it. Within the VSD it’s the capacitor bank that has created the greatest challenges, both to design and then to find a factory that can produce the number that we need. They must be self-healing and you must be able to bypass them, and nobody is making these to the right tolerances. So we are discussing with our JIP partners when to launch and the choice is to go in February or to wait until June, and I tend to believe that June is the right date,” Dahl said.
Siemens is also considering building in parallel the first commercial VSD’s due to a large demand for these units, Dahl said.
“What we may do, in parallel, is to build the first commercial VSD, because there are a few customers who really need it, and as long as you can prove it works in shallow water and you have conducted endurance tests then it’s possible,” Dahl said.
“There are a few fields owned by Petrobras and also one owned by Statoil that really need a subsea VSD so it may be that within the next few months we start building the first commercial VSD. Technically, we are there already,” he said.
Some of the world’s largest electrical engineering companies are looking to produce the first complete subsea power system.
Switzerland’s ABB is developing a system for subsea power solutions in a separate JIP involving an industry consortium led by Statoil.
The group has installed transformers on the sea bed at Statoil’s Asgard field, Tor-Eivind Moen, Vice President Electrification at ABB, told Upstream Intelligence.
“Based on present technologies ABB has provided VSDs to power the 15 mega volt amperes compressors at Åsgard via record-breaking 43 kilometer cables utilizing ABB subsea transformers” Moen said.
Other competitors working on a subsea power solution include France’s Schneider Electric and US giant GE.
Dahl said the Siemens project has the benefit of using a pressure compensated system to respond to the deep water challenges.
“You have the same pressure outside and inside the equipment, which gives you some huge benefits, firstly because you don’t need that much steel to withstand the pressure and the risk of leakage is much smaller. If you have one bar on one side and 300 bars on the other the risk is obviously much greater,” he said.
The subsea market
Moen said ABB expects the market for subsea solutions to develop at a compound annual growth rate of 10% to 2020 in a context of constrained capital costs.
Norwegian consultancy Rystad Energy said in 2013 that Subsea Expenditure in the Gulf of Mexico alone was set to rise from around $6 billion in 2013 to around $10 billion in 2020, although this was before the oil price slump.
Dahl said there were a number of advantage of working with industry partners on the Siemens JIP.
“They pay about 20% of the $100 million cost of development, and that helps a little, but what is more important is that you can get some of their experience and knowledge about their fields so that you are able then to test the technology against their needs and be sure that the market will be there,” he said.
Siemens is presently involved in “25 concrete projects” to supply the complete power system, Dahl added.
“There is also a big brownfield market. A lot of the fields in Brazil are losing pressure and need subsea pumps, and subsea pumps are getting bigger and bigger, all of them. These will be run by the VSD. Some of the fields in Brazil have a recovery rate of 30 to 40%, so it’s tempting to increase that to 60% and the cost is rather low. And in a lot brownfields you don't have the space – you can't carry any more weight on the topside.”