Chad has celebrated its entry into the world of oil exporters with a ceremony in N'Djamena.
Chad's new pipeline is more than 1,000km long
Oil has already begun flowing from Chad's oil fields through a 1,000km pipe for export from Cameroon.
"We maintained our long-term focus on this project over 27 years of effort and changes in the consortium and helped turn a vision in 1976 into a reality....we are proud of what has been accomplished," said Morris Foster, president of ExxonMobil Development Company which led the multi-billion dollar project.
On Thursday, Chadian President Idriss Deby tried to counter fears that the country's new-found oil wealth may be mismanaged.
President Deby pledged that the cash will be used responsibly, saying the country's coming oil wealth "should not divert us from our usual economic activities."
"We must build a modern and working Chad together," he added.
The new $3.7bn (£2.2bn) oil facilities are expected to boost the impoverished West African nation's revenues by at least $2bn over the next 25 years.
According to the World Bank, the money could help lift average income per head in the country from $250 to $550 a year by 2005.
But international charities have raised concerns that, as in many other oil-rich developing countries, the oil bonanza will not filter through to Chad's poor.
These fears were heightened three years ago when the government admitted diverting $4m of the pipeline's investment funds to buy weapons for use in its war against northern rebels.
The World Bank, which funded the pipeline jointly with oil giant Exxon Mobil, has stipulated that the bulk of the revenues be kept in a London bank account and subjected to close scrutiny.
Meanwhile, the Chadian government has also passed a law under which 80% of the income will be used to finance education, health, environment, water and rural development.
A watchdog body has been set up in Chad to ensure that the law is enforced.
But scepticism that the oil revenues will be used to alleviate the extreme poverty facing many of the country's eight million people linger on.
Local groups are reported to be planning a day of silent protest on Friday to coincide with the opening of the new oil complex.