Discovery of a Bolivian Foothills Giant Gas Field: Incahuasi

Abstract

This chapter will address the innovative and bold exploration approach that has led the French company Total and its Argentinean partner Tecpetrol to achieve what is one of the largest gas discoveries of the south Bolivian sub-Andean basin of the 2000–2010 decade. This discovery, named Incahuasi, is the result of multidisciplinary teamwork covering a period of 4 years from the initial geological concept definition to the drilling and testing of the discovery well Incahuasi-X1. The overall approach can be summarized as a combination of controlled risk decision making based on a regional geological knowledge and the development of new techniques such as the definition of dedicated biostratigraphy charts. This approach enabled the multidisciplinary team to manage most of the uncertainties attached to this specific foothills context and define a workflow that led to success. The successful testing of the Incahuasi-X1 exploration well in 2004 led to a multi-tcf discovery currently under development. Located more than 120 km (75 mi) north of the existing Devonian gas fields, it opened a new exploration domain. It also highlights the benefit of a multidisciplinary and innovative approach in challenging areas such as the fold belts from prospect generation to discovery in a time constraint domain.

Fold–thrust structures – where have all the buckles gone?

“…Our model differs from that of Heidmann et al (2017). We suggest that the older Silurian rocks are not involved in the Incahuasi structure and there is a décollement surface within the lower Devonian rocks (Icla Formation) beneath the Huamampampa reservoir unit.…”

“…However, being commercially sensitive, interpretation failures are rarely reported. An honourable exception is Total's development history of the Inchuasi structure in the Sub-Andean fold belt of Bolivia (Heidmann et al 2017; Fig. 7).…”

“…By the end of the campaign, the Huamampampa Formation was interpreted as folded, broadly in harmony with the upper beam. A further detachment horizon, located within the Icla Formation, was incorporated by Heidmann et al (2017) so that the older Devonian and Silurian strata could shorten by simple fault-bend folds. However, does the structural style need to vary with depth, from buckle folding at shallow levels and fault-bend folding at depth?…”

Fracture distribution on the Swift Reservoir Anticline, Montana: Implications for structural and lithological controls on fracture intensity

“…Fractured reservoirs host hydrocarbon reserves globally, and are particularly beneficial to petroleum systems with little primary porosity and permeability. Fractured reservoirs are productive from a wide range of lithologies, from sedimentary rocks such as the tight sandstones of Bolivia (Florez-Niño et al, 2005;Iñigo et al, 2012;Heidmann et al, 2017), to basement rocks such as the fractured granites of Vietnam (Cuong & Warren, 2009). These reservoirs are found in a range of geological settings, from relatively undeformed regions, where fractures form in response to regional stresses or increased pore pressure (e.g.…”