Costruyendo la Fisica sobre la Herencia de sus Pioneros
Taking Advantage of Microseismicity Induced in Oil Basins
Alvaro García M.(1) y Hansjürgen Meyer(2)
(1)UNIVERSIDAD DEL VALLE, Departamento de Física, Observatorio Sismológico del Sur Occidente
(OSSO)
(2) UNIVERSIDAD DEL VALLE, Observatorio Sismológico del Sur Occidente (OSSO), Corporación OSSO
ABSTRACT
Microseismicity generated by hydrocarbon production processes allow to investigate aspects of the
seismic process and of structures and processes relevant to the production itself, taking advantage of
the unique conditions created by the controlled intervention of the rock mass, stressed by fluids. In
a tectonically active hydrocarbon basin we determined anisotropy parameters and from these we
inferred the principal horizontal stress direction 1 = 145°, which coincides well with regional data
reported from geodetic, seismic and borehole data; in total we modeled three fracture directions
(azimuths 144°, 60° and 22°); the first two coincide with main fracture directions associated with
folding, known from core and borehole measurements. We found three anisotropic structures,
distinguished with their corresponding travel times (from S-P times); the deepest one shows all three
fracture directions and the intermediate and shallower ones only fractures at 144°.
We identified the occurrence of repeaters, which allow to reduce the uncertainties inherent to
inversions for source location and to discern specific segments of active fracture segments, as well as
monitoring with high resolution changes in the flow paths over time.
Keywords: seismic anisotropy, injection, repeaters
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