Abstract

With willingness to invest and good geology, the Unconventional Revolution will not remain a North American story. The first areas to reach economically successful developments of unconventional resources will probably be the petroleum-rich provinces with important legacy data, substantial existing infrastructure, and public acceptance. The Neuquén Basin (Argentina) is the first place where the Unconventional Revolution has been exported with success, and the Vaca Muerta play represents the first economical unconventional play outside North America.

The history of the discovery and development of the Vaca Muerta play dances for more than a decade with an intense series of events, such as the international search of new unconventional resources, the nationalization of the main operator, dramatic shifts in fiscal regime, a quick evolution of the play concepts (from vertical to horizontal wells) and of technology (from 500 to 3000 m laterals), and the Covid-19 pandemic. Nevertheless, the situation allowed conditions for economic success.

The geological knowledge of the Vaca Muerta play derives from (1) data gathered during the last decade, related to the search and discovery of the Giant Field Vaca Muerta, and (2) the legacy of 100 years of activity of the O&G industry in the Neuquén Super Basin. The integration of the geological disciplines, at different scales, presents a unique unconventional play, exceptionally thick (100–400 m), vast (30,000 km²), and porous (10%–20%), with a prograding clinoform hosting up to eight landing zones, and all types of fluid segments (from black oil to dry gas).

The current play concept consists in landing the horizontal wells in the proximal bottomsets and lower foresets of the clinoform, sectors with higher hydrocarbon potential and easier fracture growth. The rocks in these sectors show the best reservoir characteristics (averages: TOC 5%; porosity 12%; clay 10%–20%; water saturation 20%), the most adequate geomechanical properties (homogeneous rock with Young’s Modulus <4 Mpsi, low Poisson Ratio ~0.25, and interfaces with weak geomechanical contrasts), and a thick vertical stack (30–40 m) of lithofacies with the aforementioned characteristics. With this concept in mind, at least two landing zones have been fully de-risked, and other six have been confirmed.

The Vaca Muerta play has continued to progress lowering the breakeven to US$40/bbl for oil and US$2.0 MMBtu for wet gas. As activity ramps up, these values will continue to fall. The operators in the development phase believe that the combination of costs, well performance, and product prices are earning a return in their investments. In other words, the combination of below ground factors (geology) and above ground factors (contract terms, regulations, supply chain, security, market access, etc.) are allowing the development to be profitable.