By Jaylan Boyle, Contributing Reporter

An example of a semi-submersible oil drilling platform, photo by Roger Melb.
An example of a semi-submersible oil drilling platform, photo by Roger Melb.

RIO DE JANEIRO – Petrobras announced recently that a bidding process is to begin between tenders for the construction of 28 oil-drilling platforms, most of which will be employed in retrieving reserves of sub-salt Atlantic coast oil, expected to yield between fifty and eighty billion barrels, five times Brazil’s current reserves of fourteen billion barrels.

Petrobras is the world leader in deepwater oil exploration, operating facilities in 27 countries throughout the Americas, Africa, Asia and Europe.

The sub-salt fields refer to recently-discovered reserves off Brazil’s Atlantic coast which lie thousands of meters below the ocean floor and beneath a layer of unstable salt, making the reserves extremely challenging to retrieve. This type of oil field has until recently been considered cost-prohibitive to exploit; however the sub-salt Brazilian reserves are thought to be one of the largest remaining oil deposits yet untapped.

The intention to seek tender was announced on October 9 at a press conference in Rio de Janeiro with Petrobras CEO Jose Sérgio Gabrielli and other high-ranking executives in attendance. Although specific values have not yet been announced for the individual tenders, the Brazilian government has pledged a fund of R$4 Billion to ensure that the project is completed.

The bidding process will be divided into three stages, with the completed rigs expected to be operational between 2013 and 2017. “The first [construction phase] will be for seven drilling vessels with the capacity to drill at a depth of 3,000 meters from the water line. These are traditional, top devices in terms of dynamic positioning,” said Petrobras Service Director Renato Duque.

Petrobras has stipulated that the drilling machinery must be fabricated in Brazil, and at shipyards already operating in Brazil as well as foreign companies which would be prepared to build shipyards. Associated facilities in Brazil will be invited to compete for the construction concession.

Platforms constructed by foreign companies are to be leased by Petrobras, with the condition that an individual company can build no more than four structures.

Petrobras executives have not as yet been specific as to the nature of the other 21 drilling facilities, which could be either drilling vessels, semi-submersible platforms, or mono-column.

A semi-submersible platform has large buoyant pontoons below the water surface from which columns rise that support the platform itself. The fact that the pontoons are well below the surface means that the structure is relatively unaffected by wave action, essential to the stable operation of an oil drilling facility. These structures can be moved according to where they are needed; by pumping air into the pontoons, the entire structure rises in the water, enabling it to be towed to another location.

Mono-column platforms are usually unmanned, and operate as satellites that feed the ‘mothership’ platform via a pipe system.


Please enter your comment!
Please enter your name here

4 − four =