Cuba excitement: Flow tests to begin soon on key oil exploration well
By Russell Searancke / Upstream
The joint venture owners of Cuba’s promising Alameda oil exploration well are preparing for flow testing after confirming another hydrocarbon column prior to reaching total depth.
The Alameda-1 exploration well has revealed at least three independent potential oil reservoirs, and wireline logging of the deeper yet primary reservoir has been completed.
Operator Melbana Energy said logs were run over 276 metres of the Marti interval — previously known as the “I” structure — but were not able to be acquired over the bottom 16 metres, which had the strongest influx of hydrocarbons.
Data acquisition took longer than expected due to well control considerations during logging.
The lowest oil indications in Alameda-1 are more than 500 metres below the crest of the Marti structure on the pre-drill mapping, said Melbana.
Preparations are under way for flow testing the Marti interval above a high-pressure zone at the bottom of the structure. The interval drilled in the Marti structure will be plugged and a short sidetrack well drilled to about 50 meters higher than current total depth.
Flow testing of the Marti section in the sidetrack well is therefore projected to begin in about mid-April.
Melbana Energy executive chairman Andrew Purcell said: “We’re not sure if we’re seeing evidence of the full extent of this hydrocarbon interval in the Marti sheet but, even if it turns out to be so, we’ve got about 300 metres of gross hydrocarbon interval — the bottom of which is estimated to be some 500 metres from the crest of the Marti structure given we intercepted it down dip. Efforts are now turned to preparations for flow testing.”
The independent reserves expert McDaniel & Associates this month assessed that the three oil reservoirs encountered at Alameda-1 in the “upper sheet” contained 2.5 billion barrels of oil in place; had a combined 119 million barrels of prospective resource on a 100% basis; and had an 86% chance of geological success in at least one of the three zones.
Melbana has renamed the three upper zones Amistad (formerly the Upper Sheet zone), Alameda (formerly the N Sheet Duplex) and Marti (formerly the I Sheet Duplex).
A separate assessment of the deeper objectives will be done once the drilling and flow testing has been completed.
The Alameda-1 onshore well was spudded in Block 9 on 13 September 2021 by a joint venture of Melbana and Sonangol.
Following completion of Alameda-1, the rig will be moved to the well pad that has been constructed nearby to begin drilling of the Zapato-1 well.
