Cairn Energy has completed successful testing of the SNE-2 appraisal well and achieved positive results in offshore Senegal.
The company said high-quality oil at a rate of around 8,000 barrels per day (bopd) has been produced from the well located around 100km off the coast of Senegal.
After conducting drilling, coring, logging and drill-stem testing (DST), the company completed operations safely.
Later on, the well will be plugged and abandoned.
Following the successful appraisal well, Cairn Energy plans to revise resource estimates for the SNE field.
The well is located in 1,200m water depth and is around 100km offshore in the Sangomar offshore block.
Cairn Energy has been appraising the 2014 discovery of oil in the SNE-1 well located 3km to the south.
Cairn Energy chief executive Simon Thomson said: "We are delighted with the results of the SNE-2 well and in particular the well tests, which are significant in demonstrating the ability of the reservoirs to flow at commercially viable rates.
"The results help to confirm the overall scale and extent of the resource base in Senegal and further appraisal activity is expected to lead to future revision of the estimates."
The company also said that relatively low quality heterolithic pay flowed at a maximum rate of 1,000 bopd at another depth in the same well.
Cairn Energy operates and owns 40% of three blocks off the coast of Senegal. The other partners are ConocoPhillips, FAR and Petrosen.