Multi-Scale Fracture Characterization of a Carbonate Reservoir, Based on Remote Sensing, Outcrop Data and Thin Sections: a Case Study from the Neuquen Basin, Argentina

J. Witte¹

¹International Geoconsulting

Abstract

Extensive field work was conducted to collect detailed data of more than 20.000 individual fractures across the N-S trending, ~50km long, thick-skinned Malargue Anticline, located in the northern Neuquen Basin of Argentina. New results are presented, extracted from the statistical data, regarding fracture orientations, densities and apertures.

The examined carbonate reservoir is the Valanginian Chachao Formation, a key reservoir in the region. More than 100 fracture measure stations were registered across the anticline. The majority of the stations are located on pavements, representing the top of the Chachao Formation. At each station, comprising a standard box (40m by 40m), reservoir-relevant parameters were collected for all visible fractures, including orientation, density, spacing, length, morphology, aperture, mineral fill, open or closed attitude of the fractures. Additionally, in the core of the anticline several hundred fracture orientation data points were collected from outcrops of the underlying Choyoi Group (intrusives, volcanoclastics), the economic basement in this area. At three stations at the southern plunge and backlimb, oriented thin sections were extracted from the limestone for fracture orientation assessment. Finally all fracture data was fed into an GIS database.