The controversial Corrib gas project in Co Mayo will contribute €3 billion euro in GDP over the lifetime of the project, which is estimated at 20 years.
Currently the site employs 400 people and next year as construction nears completion, 700 will be employed.
A report published today by Goodbody Economic Consultants - and commissioned by the Corrib operators - points out that this job creation is indirect and temporary, as Shell - the company behind the Corrib gas project - mainly employs contractors.
During the construction period, Goodbody estimates the project will contribute half a billion euro to GDP.
The Goodbody report also says that at peak production, Corrib will produce almost 60% of Ireland's gas needs and that without it by 2015 99% of our gas needs will be imported.
Shell says construction will be finished at the site in about two years and production will start early in 2010. Peak production is expected shortly afterwards.
The report also says that controversy surrounding the project and difficulty with planning and licensing had the potential to damage Ireland's reputation as a place to explore for and produce gas and oil.