Pura Vida shares were $0.455 when the well spudded and were $0.26 at close yesterday night.

In early trade this morning the shares were at $0.12, down 54%, as investors digested the news of other another Moroccan disappointment, with the two shallow secondary prospects lacking in either reservoir development or oil shows.

Drilling of the MZ-1 well with US concern Freeport-McMoRan found a lack of an effective reservoir in either of the secondary large structural four-way dip closure objectives in the Cenomanian and Aptian intervals.

There were no oil shows encountered during wireline logs.

The best chance of success in MZ-1 was considered the Aptian formation, which had a 30% probability of geologic success.

The well is at a depth of 4653m within the Lower Cretaceous section.

The JV will run casing and continue drilling to a proposed target depth of 5600m to assess the primary two Jurassic basin floor fan targets.

After drilling through the two remaining targets a decision will be made whether to deepen the well to 6150m to test a third Jurassic fan.

The Jurassic targets are combined stratigraphic/structural traps interbedded within the expected source rocks of the basin and are ideally positioned to receive migrating hydrocarbons directly from the source rocks into the fan systems and carrier beds.

"We are disappointed that the well failed to encounter reservoir in the secondary objectives in the Cretaceous, however, we expect to intersect the primary targets in the Jurassic and look forward to reporting those results shortly," Pura Vida managing director Damon Neaves said of the company's first well.

MZ-1's drilling took more than three years to plan, and is being drilled with the Atwood Achiever deepwater drillship.

The well was intending to test up to five stacked prospects with total gross unrisked mean prospective resources of over 1.4 billion barrels, or around 328 million bbl net to Pura Vida, with gross upside to over 3Bbbl.

MZ-1 replaced the earlier 1.5Bbbl Toubkal prospect as the most promising target and spudded on June 1.

The drilling is taking place in 2176m of water.

Pura Vida is being funded through two wells to a cap of at least $US215 million ($A281 million), with an estimated well cost for MZ-1 of $136.6 million.

The company also has interests in Gabon and Madagascar.