by TheDude » Fri 22 Aug 2008, 17:37:00
As I understand these things water would be secondary recovery, N[sub]2[/sub] etc. tertiary. Cantarell's remarkable gas cap meant Pemex didn't have to do much with the field for years. Geology turned out to be the deciding factor.
Here's a good overview from
Offshore Technology.
$this->bbcode_second_pass_quote('', 'A')s gas is at a premium in Mexico, Pemex knew it could put the gas to better use by selling it. So Bechtel and Pemex studied other options, such as steam and water injection. Because of the oil field’s geological formation, neither of these turned out to be a viable solution. But nitrogen was. After six months of study, the team recommended that nitrogen be used to pressurise the reservoir and enhance production at Cantarell.
That nitrogen plant was built with assistance from, horrors, outside contractors:
$this->bbcode_second_pass_quote('', 'T')he plant was built by a consortium including Empresas ICA of Mexico and Fluor Corp of the US; gas companies Linde and BOC Group; Westcoast Energy of Canada (a gas pipeline company later acquired by Spectra Energy); and Marubeni. The plant is owned and operated by a joint venture company which is majority-owned by BOC Group, which was itself acquired by Linde in 2006.
The injection project started operating in 2000, and boosted production from about a million barrels a day to 1.6 million barrels a day, then to 1.9 million barrels a day in 2002 and to a peak of 2.1 million barrels a day in 2004, at the time making Cantarell the second-fastest producing oil field in the world, behind Ghawar Field in Saudi Arabia.
However, Cantarell is now in relentless decline. As long ago as August 2004, Pemex announced that actual oil output from the field was forecast to decline steeply from 2006 onwards, at a rate of 14% a year.