The company's initial review of the Lower Sheet Play assessed a potential 8.12 billion barrels of oil-in-place, with a recoverable 395MMbbl, but recent work since has managed to boost the in-place potential to some 12Bbbl and double the recoverable potential to 612MMbbl.
Melbana managing director Peter Stickland said a lot of work had gone into the high-graded Alameda prospect, which had emerged as the prime drilling candidate.
"We are highly encouraged by the continued growth in the exploration potential of the Block 9 PSC," he said.
"It is extraordinary to be able to identify exploration potential for 612MMbbl of prospective resources in conventional targets in a proven trend at moderate target depths, located in an accessible onshore area.
"Significantly, these leads have the potential for billions of barrels of oil-in-place, however the prospective resources so far assume only the historical 5% recovery factor from offset fields in Cuba.
"The application of modern enhanced oil recovery techniques may increase the recovery factor and therefore has the potential to substantially increase the potential recoverable oil."
The Melbourne-based junior is planning a two-well accelerated program, with the aim of spudding its first well within a year of nailing down its best targets.
It has 18 prospects and leads to choose from along trend from the multi-billion barrel Varadero oil field.
Alameda is close to Marti-5, which recovered 24 degree API oil in 1988 at unknown rates.
The Lower Sheet Play is between 2000-3500m depth, and sits below the Upper Sheet (between 800m and 3500m and a shallow Tertiary play (between 400m and 1200m).
Lower Sheet targets are a conventional, fractured carbonate reservoir, similar to existing producing fields in Cuba, and can flow at up to 4000bopd.
Alameda, previously known as I Lead, is in a similar structural position to the Varadero field, which sits some 35km away.
Alameda has an estimated chance of discovery of 32% and recoverable volumes ranging from a modest 3MMbbl to 214MMbbl with a best estimate of 65 million barrels recoverable.
The well into Alameda will also test the N Lead, and the secondary potential for Upper Sheet oil, supported by the 1973 shows in the Marti-2 well.
While the Upper Sheet and Tertiary Sheet Plays have been reviewed and continue to be considered prospective, Melbana has decided not to mature structural leads into prospects because of data limitations and the suggestion that Lower Sheet oil will be better quality and the Upper Sheet targets are typically smaller.
The planned drilling will treat the shallower plays as secondary targets, and will primarily be focused on gathering data in those zones.
The second well is being considered to test either the A2 or C1 leads in the central area of Block 9.
A2 Lead has a 21% chance of success and has a prospective resource potential of 69MMbbl while C1 has a 25% chance of success and a potential for 71MMbbl.
While A2 is near some historic oil shows, C1 is just 13km from the 1881 Motembo light oil discovery.