ANÁLISIS ESTRUCTURAL DEL ÁREA AGUA BOTADA (FAJA PLEGADA Y CORRIDA MALARGÜE) Y SU RELACIÓN CON POTENCIALES RESERVORIOS ÍGNEOS

BARRIONUEVO, M.; DE LA CAL, H.; MESCUA, J.F.; GIAMBIAGI, L.B.; SURIANO, J.; SOTO, J.L.

Mendoza

Congreso; X Congreso de Exploración y Desarrollo de Hidrocarburos; 2018

Instituto Argentino del Petróleo y el Gas

Structural analysis of Agua Botada oil-field (Malargüe fold-and-thrust belt) and its relationship with potential igneous reservoirs.In the southern part of Mendoza province, Neuquén Basin, igneous intrusives hosted in the Mezosoic sedimentary succession produce oil in some regions of the basin as in the Valle del Río Grande area. 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 the deformation 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 and seismic data) to understand the kinematic evolution of the structures. Previous NNW rift faults show inversion under andean compression while NW to WNW rift faults are probably not inverted but reactivated as strike-slip fault.In addition the igneous bodies were surveyed and when possible, slip data was obtained. The inversion of these data provided the stress field responsible of faulting which is inferred to be coeval and related to the intrusion. Dykes and sills were recognized: dykes striking NW to WNW show strike-slip faulting with hydrothermal alteration and hydrocarbon traces, while E-W striking dykes arenot sheared and show weak hydrothermal alteration and no traces of ydrocarbons; some sills are faulted as well with the same kinematic as faulted dykes and some are intruded using reverse fault planes, showing hydrothermal alteration and oil traces. The swarms of igneous bodies irradiate from two 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 model with three main stages: in the first stage from 17-10 Ma Agua Botada field was in the foredeep of the foreland 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 with igneous emplacement as sills in reverse faults. In the eastern zone a strike-slip to compressional stress field reactived the previous rift faults which were suitable as magmatic flow paths. Finally in the third stage (7-1 Ma) the deformation front migrated toward the east with the inversion of Malargüe normal fault that tilted the mesozoic sediments.