Presentaciones a Congresos

Permanent URI for this collection

http://ri.itba.edu.ar/handle/123456789/71

Browse

Now showing 1 - 2 of 2

Depositional controls over the lacustrine source rocks of the cuyana basin: an approach to model a mechanical cyclicity through an integrated analysis of sequence stratigraphy, petrophysics and rock properties
(2017-05) Barredo, Silvia; Sosa Massaro, Agustín; Fuenmayor, Evanna; Abalos, Roxana; Stinco, Luis; Abarzúa, Fernando
"Integrating field and laboratory data is possible if there are strong geologic criteria to relate them. This challenge demands understanding rocks from the fabric and mineralogy up to the architectural elements of rock bodies at a basinal scale. The geological properties of rocks, being them clastic, chemical or biochemical, influence reservoir quality and hydrocarbon producibility, but continental mudrocks/siltstones (shales) are by far more complex because of their depositional nature and ighly variable vertical and lateral sedimentary characteristics. Grain size variability and sedimentary structures are common in these rocks. From outcrops, well logs and the source rocks of the Cuyana Basin (Argentina) could be characterized as deposited in lacustrine environments under a strong tectonic and climatic influence. Silty sandstones, limestones, massive and laminated bituminous shales developed in underfilled and balanced to overfilled lakes. They display arallel/inclined/rippled laminations, coarsening/fining upwards patterns, nodules, scour surfaces and pedogenic features. Total organic content may reach 14 % and corresponds to macro and micro floral remains, reshwater invertebrates and kerogen types I and II. These lithofacies are vertically stacked in patterns that can be related to cycles with different mechanical properties. In outcrops and with the help of seismic lines third order depositional sequences representing basin variations in accommodation space were recognized as low accommodation (LAS) to high accommodation (HAS) sequences developed in each of the three rifting stages. Using detailed information about mineralogy and fossil content climate was characterized and fourth order parasequences could be characterized. Fifth order (bedset-rhythms) cycles were interpreted on the basis of outcrops and well logs. Inorganic (especially clays) and organic content, pedogenic fabric, burrows and microfracturing represent weakness planes and as they vary according to these cycles, it was possible to model a mechanical cyclicity along the whole lacustrine column and to analyze their depositional controls. This integrated study has provided relevant data for the understanding of the geological and mechanical properties that will contribute to the optimization of fracture programs."
A fluid structure interaction model for hydraulic fracture simulation on Vaca Muerta Argentina shale formation
(2017) Alderete, Ignacio D.; Sosa Massaro, Agustín; D'hers, Sebastián
"Vaca Muerta Formation in Neuquén Basin, Argentina, is one of the great worldwide promises given its potential as a non-conventional reservoir. Because of the intrinsic heterogeneity and low permeability, hydraulic fracturing is a required operation to stimulate the reservoir for better production. Simulation becomes a desirable tool to make fractures more efficient and get predictable outcomes. For this purpose, a 3D finite element analysis is performed using ADINA software to model reservoir response during the hydraulic fracturing process. This iterative, fully coupled model uses fluid structure interaction (FSI), porous elastic media and stratified materials with transversely isotropic (TI) properties. The allowed fracture distribution is proposed beforehand. A cohesive model is added via non linear springs placed along the fracture proposed path. Material models are calibrated using data from well logs and microseismics taken from one well located in the field. All the information obtained from that well is then filtered for a particular region of interest in depth, determined by the mechanical properties observed. Regarding the calculation procedure, as initial condition for the stimulated reservoir volume (SRV) the stress strain state measured in the field is adopted. Then hydraulic fracture process is simulated pumping fluid through punched holes and then fracture opening is analyzed, based on nodes displacement along the proposed path, to characterize fracture's opening and extension. The resulting state of stress developed after the fracture is updated at every calculation step. Key information such as resulting pore pressure and effective stresses can be easily computed along the fracturing process. Once obtained results are compared to analytical solutions and experimental data obtained from fractures performed in similar soil conditions with good agreement. The developed model can tackle a variety of reservoir volumes, considering stratification, geomechanical properties, fracture fluid, fracture paths and the initial state of stress. Natural cracks can be added in a rather simple fashion by adding fractures to the proposed distribution with adequate fracture strengths."

Browse

Browsing Presentaciones a Congresos by Author "Sosa Massaro, Agustín"

Results Per Page

Sort Options