Repsol YPF said it has identified the existence of a recoverable 927 million bbl of oil equivalent, 80% oil, in Late Jurassic-Early Cretaceous Vaca Muerta shale on about 3.5% of its 12,000 sq km holdings in the Neuquen basin in Argentina.
The company derived its estimates from the results of 15 vertical wells completed in the unconventional formation on 428 sq km on the Loma La Lata Norte block. It said one other well is already producing from Vaca Muerta in a separate 502 sq km area in the basin.
Repsol termed the 927 million boe the company’s largest oil discovery and said the volume is similar to the existing reserves of Argentina firm YPF, in which Repsol holds a 58% interest.
Repsol noted that the Vaca Muerta formation underlies 30,000 sq km in the Neuquen basin and that Wood Mackenzie consultants has identified the formation as “one of the world’s best shale plays.”
Wood Mackenzie’s evaluation, completed earlier in 2011, was based on numerous factors including development of the hydrocarbons market, infrastructure, regulation, availability of water, fiscal terms, quality, comparative volume, potential for enhanced recovery, and organization of the supply chain, Repsol said.
Repsol said the 15 vertical wells at Loma La Lata Norte had initial flow rates of a combined 5,000 b/d of oil equivalent including 40-45° gravity oil.
Meanwhile, the single well in the 502 sq km area is producing 400 b/d of oil equivalent with 35° gravity oil. The 502 sq km area “has significant potential for large volumes to be developed in the future once the appropriate studies and preliminary work to determine resources is completed,” the company said.