Maturation of the Vaca Muerta and Agrio Formations due to the emplacement of magmatic intrusive complexes in the southern Men-doza region of the Neuquén Basin

La existencia de complejos intrusivos en cuencas sedimentarias ha sido documentada en varias cuencas en distintas partes delmundo. Generalmente se emplazan en rocas ricas en materia orgánica, produciendo la maduración de la misma. Además, el emplazamientopuede generar vías de migración de fluidos, estructuras que pueden ser posibles trampas de hidrocarburos, y pueden serreservorios fracturados. Este trabajo se focalizará en el impacto térmico y la consecuente generación de hidrocarburos producidospor el emplazamiento de un complejo intrusivo. Para ello se escogió el sector surmendocino de la Cuenca Neuquina, dónde existengran cantidad de intrusiones ígneas emplazadas en las rocas generadoras del Grupo Mendoza (Formaciones Vaca Muerta y Agrio)y en sedimentitas continentales del Grupo Neuquén. Se realizó la identificación de intrusivos mediante datos de sísmica y pozos. Seconfeccionó una sección estructural de la zona de estudio, para luego realizar los modelos termales. Los resultados de las modelizacionesmuestran que el emplazamiento de intrusivos genera la maduración de las Formaciones Vaca Muerta y Agrio, especialmentedonde se produce una clusterización de los intrusivos. Éste efecto está regulado por la temperatura de la roca de caja al tiempo delemplazamiento, la edad del emplazamiento y el solapamiento de las intrusiones. Se concluye que en la región surmendocina de laCuenca Neuquina, las Formaciones Vaca Muerta y Agrio se encuentran maduradas por el impacto térmico de un complejo intrusivo,pudiendo llegar a generar cantidades considerables de hidrocarburos.The existence of intrusive-complexes in sedimentary basins has been documented in many basins all around the world. Generally, they are emplaced in organic rich rocks, producing their maturation. Also, the emplacement can generate fluid's migration conduits, structures that can be hydrocarbon traps, and fractured reservoirs. This paper will focus on the thermal impact and the consequent hydrocarbon generation produced by the emplacement of an intrusive-complex. For that aim, we have chosen the southern Mendoza area of the Neuquén Basin, where a great quantity of igneous intrusions are emplaced in the source rocks of the Mendoza Group (Vaca Muerta and Agrio Formations), and in continental sedimentites of the Neuquén Group. The identification of the intrusives was made based on seismic and borehole data. We produced a structural section of the study area, which was used afterwards to make the thermal models. The results of our modellings show that the emplacement of intrusives generates the maturation of the Vaca Muerta and Agrio Formations, especially where a clustering of the intrusions is produced. This effect is regulated by the temperature of the host rock at the time of emplacement, the age of the emplacement, and the clustering of intrusions. We conclude that in the southern Mendoza region of the Neuquén Basin, the Vaca Muerta and Agrio Formations were matured because of the thermal impact of an intrusive complex, being able to generate considerable amount of hydrocarbons.Fil: Spacapan, Juan Bautista. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; Argentina. YPF - Tecnología; ArgentinaFil: Palma, Joaquín Octavio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. YPF - Tecnología; ArgentinaFil: Rocha Vargas, Marcelo Emilio. YPF - Tecnología; ArgentinaFil: Leanza, Hector Armando. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; ArgentinaFil: D'Odorico, Alejandro. YPF - Tecnología; ArgentinaFil: Rojas Vera, Emilio Agustin. YPF - Tecnología; ArgentinaFil: Manceda, René Enrique. YPF - Tecnología; ArgentinaFil: Galland, Olivier. University of Oslo; NoruegaFil: Medialdea, Adrián. YPF - Tecnología; ArgentinaFil: Cattaneo, Diego Matias. YPF - Tecnología; Argentin

Crustal motion in the Southern Andes (26°-36°S): Do the Andes behave like a microplate?

[1] A new Global Positioning System (GPS)-derived velocity field for the Andes mountains (26°-36°S) allows analysis of instantaneous partitioning between elastic and anelastic deformation at the orogen\u27s opposing sides. Adding an \u27\u27Andes\u27\u27 microplate to the traditional description of Nazca-South America plate convergence provides the kinematic framework for nearly complete explanation of the observed velocity field. The results suggest the oceanic Nazca boundary is fully locked while the continental backarc boundary creeps continuously at ̃4.5 mm/yr. The excellent fit of model to data (1.7 mm/yr RMS velocity misfit), and the relative aseismicity of the upper crust in the interior Andean region in comparison with its boundaries, supports the notion that the mountains are not currently accruing significant permanent strains. Additionally, the model implies permanent deformation is not accumulating throughout the backarc contractional wedge, but rather that the deformation is accommodated only within a narrow deformational zone in the backarc

Thermal impact of igneous sill-complexes on organic-rich formations and implications for petroleum systems: A case study in the northern Neuquén Basin, Argentina

Numerous sedimentary basins in the world host voluminous igneous sill-complexes, i.e. stacking of sills that are emplaced in different levels of the sedimentary sequence. When sills are emplaced in organic-rich sedimentary formations, they can considerably affect the thermal and maturation history of the hydrocarbon source rock and can be highly relevant elements of the petroleum system. Most models of the thermal impacts of igneous sills on source rock consider one or few intrusions. However, the parameters that govern host rock maturation related to full sill-complexes remain unclear. In this contribution, we integrate borehole data and thermal 2D-modelling to quantify the temperature and maturation effects of a sill-complex in a 2D section on the sedimentary formations of the Neuquén basin, Argentina. In this basin, extensive magmatic activity took place during Oligocene-Miocene and upper Miocene age. There are numerous magmatic intrusions, dominantly sills, emplaced in organic-rich shale formations in the study area. Our modelling results show that (1) the source rock maturation in the study area was dominantly triggered by the sills, so that the area would be immature without the sills, (2) multiple sills have more pronounced thermal impact than a single, thick sill, (3) volumes of host rock between intrusions can have different degree of maturation depending on intrusion spacing, and (4) the temperature of the host rock at the time of sill emplacement controls to a great extent the thermal and maturation impact of the sills. Our work provides valuable insights into how the sills affected hydrocarbon generation during Oligocene-Miocene and Upper Miocene magmatic activity in the Neuquén basin. In addition, our study suggests that most of the kerogen has been transformed to hydrocarbon in areas where the sills are located.Fil: Spacapan, Juan Bautista. YPF - Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Palma, Joaquín Octavio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. YPF - Tecnología; ArgentinaFil: Galland, Olivier. University of Oslo; NoruegaFil: Manceda, René. YPF - Tecnología; ArgentinaFil: Rocha, Emilio. YPF - Tecnología; ArgentinaFil: D Odorico A.. YPF - Tecnología; ArgentinaFil: Leanza, Hector Armando. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; Argentin