Ghanaian president John Atta Mills opened the valves at a televised ceremony to mark the nation’s first oil output, around 40 miles off the west African coast.
Production at the Jubilee field, which is managed by Tullow, will start at 120,000 barrels per day, and is expected to double within three years.
Mills warned that the lucrative find “means that we are assuming a very serious responsibility. And especially for those who are in leadership positions, we must ensure that it becomes a blessing not a curse.”
However, Evolution Securities said in a note the start of production “is a timely reminder of how far Tullow has come in a very short space of time in Ghana with Jubilee on stream just three and a half years after its discovery”.
Tullow remains locked in disputes with the Democratic Republic of Congo and Uganda over its licenses for oil fields in the countries.
Its shares fell 1.7 per cent to close at 1,215p.