Irish-founded oil and gas explorer Tullow Oil has cut its production forecast for output at its Ten project, offshore Ghana.

Production at the field, which drew first oil in mid-August, is now expected to to reach 15,000 barrels a day this year. This compares to a previous guidance of 23,000 barrels a day.

The explorer said production ramp-up to the end of October at the project was impacted by issues with water injection systems.

Tullow forecast output of between 64,000 to 67,000 barrels a day for its West African assets for 2016, down from a previous guidance of 62,000 to 68,000, due to the reduced production from the Ten project.

Jubilee field

Gross production from the Jubilee field, also in Ghana, has been steady at about 100,000 barrels of oil a day since August, the group said. Jubilee field gross production remains unchanged at 74,000 barrels a day.

The group's non-operated Africa portfolio is on track to produce 28,000 barrels of oil per day in the current year, it said.

"Our major capital commitments came to an end and our low-cost West Africa oil production is increasing substantially. As a result, we will start to generate free cash flow in this quarter and will begin the process of deleveraging our balance sheet. We have also made good progress with the turret remediation project at Jubilee and coverage has been affirmed with our insurers for the repair and business interruption," said chief executive Aidan Heavey.

Tullow said it expected to end 2016 with net debt of approximately $4.9 billion.

In a note to investors, Davy analyst Caren Crowley said she believed the market had already priced in the slower ramp-up at Ten and an insurance pay-out linked to the Jubilee project.

Shares in the explorer were up 3 per cent in early trading following the update.