Geological Characterization of the Emerging Mesozoic Shale Plays in Latin America
Pliego Vidal, Elia1; Sanchez-Ferrer, Fernando; Jensen, Luke; Goudy, Cheryl; Jeremiah, Jason; and Tepper, Brian
With the growing success of unconventional plays in the US in recent years, some of Latin America’s basins, such as Neuquén in Argentina or Middle Magdalena Valley in Colombia, have gotten the industry’s attention. These basins are characterized by world-class source rocks of Mesozoic age. Although commercial unconventional production has been established in some cases, most notably for Neuquén’s Vaca Muerta Formation, other candidates exist in under-explored/frontier basins that can be pursued as shale plays.
This work provides an overview of the main Mesozoic shales in Latin America, extending from Mexico to Chile, describing and comparing the geological features and relative potential of these source rocks. These shales were deposited in a variety of lacustrine and marine settings. Though available published data on shale characteristics can be limited, some comparisons between the potential resource plays can be drawn.
The most important marine shales in terms of potential resources are (1) Late Jurassic – Lower Cretaceous and (2) Middle – Upper Cretaceous. The first group is represented by the Vaca Muerta Formation in Argentina and Pimienta – La Casita Formations in Mexico, source rocks which are responsible for charging major conventional fields in both countries. The second group is represented by the La Luna Formation, documented as the main source rock in Colombia and Venezuela, and the Eagle Ford shale in Mexico (extension of the established US play).
Lacustrine systems can exhibit great organic richness, but show lateral and vertical variability and in some cases strong volcanic influence, e.g. the Magallanes basin in Chile, San Jorge and Cuyo basins in Argentina. Lacustrine and deltaic shales have a relatively small areal distribution associated with rift grabens.
In this early phase of exploration for resource plays across Latin America, evaluation of the various opportunities relies heavily on the application of basic "first principles" and geological play analogues. As experience in North America shows, understanding of local variability within an area of interest will play an important part in the identification of the final "sweetspots", and their potential to be determined ultimately by the drill-bit.
AAPG Search and Discovery Article #90166©2013 AAPG International Conference & Exhibition, Cartagena, Colombia, 8-11 September 2013