Análisis estructural del área Agua Botada (faja plegada y corrida Malargüe) y su relación con potenciales reservorios ígneos.

BARRIONUEVO, MATÍAS; DE LA CAL, HERNÁN; MESCUA, JOSÉ; GIAMBIAGI, LAURA; SURIANO, JULIETA; SOTO, JORGE LUIS

Mendoza

Congreso; 10º Congreso de Exploración y Desarrollo de Hidrocarburos.; 2018

Instituto Argentino del Petróleo y del Gas

Structural analysis of Agua Botada oil-field (Malargüe fold-and-thrust belt) and its relationship withpotential igneous reservoirsIn the southern part of Mendoza province, Neuquén Basin, igneous intrusives hosted in the Mezosoicsedimentary succession produce oil in some regions of the basin as in the Valle del Río Grandearea. In order to evaluate the relationship between the structural evolution and the igneous bodiesintrusion, a structural study of the Agua Botada field (north of Valle del Río Grande area) near thedeformation front of the Malargüe fold-and-thrust belt, is presented here.A 3D structural model was developed using surface and subsurface information (oil-well logs andseismic data) to understand the kinematic evolution of the structures. Previous NNW rift faults showinversion under andean compression while NW to WNW rift faults are probably not inverted butreactivated as strike-slip fault.In addition the igneous bodies were surveyed and when possible, slip data was obtained. Theinversion of these data provided the stress field responsible of faulting which is inferred to be coevaland related to the intrusion. Dykes and sills were recognized: dykes striking NW to WNW showstrike-slip faulting with hydrothermal alteration and hydrocarbon traces, while E-W striking dykes arenot sheared and show weak hydrothermal alteration and no traces of hydrocarbons; some sills arefaulted as well with the same kinematic as faulted dykes and some are intruded using reverse faultplanes, showing hydrothermal alteration and oil traces. The swarms of igneous bodies irradiate fromtwo main feeders and show a general WNW trending which coincides with previous normal faults.The interpretation of the obtained structural data allowed to develop a geological evolution modelwith three main stages: in the first stage from 17-10 Ma Agua Botada field was in the foredeep of theforeland basin and the compression took place to the west of it. In the second stage (10-7 Ma) thedeformation migrated to the east and the western part of Agua Botada was under compression withigneous emplacement as sills in reverse faults. In the eastern zone a strike-slip to compressionalstress field reactived the previous rift faults which were suitable as magmatic flow paths. Finally inthe third stage (7-1 Ma) the deformation front migrated toward the east with the inversion of Malargüenormal fault that tilted the mesozoic sediments.