The southern flank of the Neuquen embayment, defined by the Huincul intraplate deformation belt, remains nowadays almost unexplored for unconventional Shale hydrocarbons. Despite the presence of both, Vaca Muerta and Los Molles unconventional targets, several key factors contribute to less exploration efforts, compared to the higher maturity drilling stage in Vaca Muerta black oil zone along the basin center and eastern margin.
Critical factors include, among others, the presence of a single Vaca Muerta Landing zone (cocina), the strong control of intraplate tectonics in the thickness and facies distribution of Los Molles potential landing intervals, short distance maturity changes, complex structural setting and steeper navigation angles of 70-80 °.
Recent drilling exploration activity (2018-2019) lead to the discovery of Puesto Parada x-2(h) well, Neuquen basin southernmost Vaca Muerta economic oil find. Additionally, Punta Senillosa-1011, became the first well to fracture and successfully test the underlying Los Molles Fm. unconventional shale oil play in the basin. Both wells are located along the northern flank and eastern plunge of the Huincul intraplate deformation belt.
Here, we present the geological, geochemical, geophysical and geomechanical characterization of both discoveries. Focus is made in key success factors.
The study area (400km2) is located eastern plunge of the Huincul intraplate deformation belt that extends along the southern margin of the basin (Figure 1). Its Early Jurassic-Late Cretaceuos tectonic activity result in a complex structural setting of compressional faults, oblique invertion of hemigrabens, transpressional and transtentional faulting (Silvestro & Zubiri 2008). It strongly controlled the sedimentary record (Figure 2) by the development of erosional unconformities, wedge geometries and other sintectonic sedimentary patterns, affecting thus facies distribution, thickness and the preservation of the different units. This geological setting provides a more complex geological framework for unconventional play exploration compared to the central and eastern portions of the Neuquen Embayment.
