The company holds the permit under a PSC with the government, alongside partner Sonangol. 

Last week the company reported high quality oil shows at the company's first primary target - the N Sheet. 

Melbana told the market this morning that drilling reached a depth of around 3590 metres overnight at which point a lithology change was detected, meaning it has possibly reached the bottom of the reservoir and has subsequently called total depth for the current 8½ inch section to preserve the oil already found in this section. 

The interval just drilled started at around 3077m, indicating a potential gross reservoir interval of possibly as much as 500m. 

The company noted that gas behaviour in this interval was better than expected and there have been significant oil shows present throughout on the shale shakers and in cutting samples. 

Drilling of this section began with a mud weight of 1.54sg and had to increase up to 1.73sg to maintain well control . 

Melbana said preparations are now underway to log the section just drilled, which will give it a better understanding of the hydrocarbons it has encountered. 

Once it finishes logging, the 7" liner will be set before drilling ahead into the deeper zone with a 6" hole to test the Alameda structure - the second and largest primary target for the well. 

"This well is not affording much chance for rest for your hardworking team here on the ground in Cuba but no one is complaining given what this well continues to tell us," Melbana executive chairman Andrew Purcell said. 

"We're all looking forward to the results of the forthcoming logging program to learn more about this extensive oil interval we've intersected."

Melbana shares have skyrocketd up 40% in lunch time trade, reaching 5.2c.