The company completed the placing of 22 million new shares, equivalent to about 11 per cent of the its existing share capital, in just three hours amid strong institutional demand.
Earlier this month the company said its Sapele-1 well off the coast of Cameroon had made two significant hydrocarbon discoveries and an update this week added that it had found additional volumes.
The firm said it will continue to drill down and is expected to reach target depth in the next 20 to 30 days.
The well is a block which is one of three of permits in the Douala basin off Cameroon.
The company said the additional funds raised could be used to contract a second rig, drill more wells and carry out further exploration work both off the coast of and in the West African country.
Chief executive Kevin Hart said the placing would provide "financial flexibility" for work across its interests in 2011.
"We are looking forward to delivering material value for shareholders through this programme."
Shares in Bowleven closed down 13p at 325p.