If oil prices, currently at around $76 a barrel, average $70 for the remainder of the year, operating cashflow would go up by $50 million, it added.
Tullow, which refinanced it $2.3 billion debt pile this year to extend maturities, expects to invest $250 million, mainly on drilling in Ghana, and financing costs of $290 million.
Tullow, which has a market capitalisation of $1 billion, is guiding for output to stay steady at around 60,000 barrels per day.
It has hedged most of its output for the rest of the year at an average price of $67 a barrel and about half of its output at $72 next year with smaller amounts hedged into 2024.
(Reporting by Shadia Nasralla; editing by Louise Heavens and Jason Neely)