An independent resource evaluation of the seven Portugal concessions in which Porto Energy Corp., The Woodlands, Tex., maintains an interest indicates a Lower Jurassic Lias best estimate prospective resource of 366.8 million bbl of oil equivalent, nearly three times the previous estimate, the company noted.
The Lusitanian basin evaluation reduced the prospective resource associated with conventional Jurassic reef exploratory targets, but that decline was more than offset by the increased geologic chance of success of finding hydrocarbon-bearing reservoirs in the presalt Silves as confirmed by the ALC-1 well, Porto Energy said (OGJ, Dec. 9, 2002, p. 32).
Narrowing the company’s focus to the Lias unconventional resource and presalt conventional plays will help concentrate farmout efforts, it added.
Phase I work to characterize the Jurassic Lias resource play included finalized aeromagnetic data over the blocks, the drilling and analysis of 23 shallow wells, and the development of a Lias deposition model that greatly increased the company’s understanding of the Lias marls in the central and northern blocks. This work underpinned the updated report and points to a very prospective unconventional resource play that merits further technical evaluation, Porto Energy said.
The Alcobaca-1 presalt exploratory well in the Aljubarrota-3 concession was a subcommercial gas discovery but helped to confirm gas-bearing reservoirs. The well greatly derisked other presalt prospects by confirming source rock, reservoir-bearing sands, and trapping mechanism in the Silves interval.
In total, the updated report has a combined contingent plus prospective resource base comprised of 47% oil and 53% natural gas.
Porto Energy’s Mohave Oil & Gas subsidiary’s concession interests in the basin are Aljubarrota-3 42%, Torres Vedras-3 100%, Sao Pedro de Muel-2 94%, Cabo Mondego-2 70%, Rio Maior-2 100%, Zambujal 72%, and Peniche 50%.
