Imaging pre-existing geological complex structure using microseismic monitoring

Unlike most of the United States unconventional plays, the Neuquén basin is characterized by high horizontal stress anisotropy, which influences the hydraulic fracture behaviour by reactivating natural faults and fractures favourably oriented. Surface microseismic monitoring was used as an imaging tool to characterize the hydraulic fracturing process on a vertical pilot well in the Neuquén basin.

More than just frac length, width and height, microseismic monitoring allowed imaging a complex 3D geometry of pre-existing geological structures. We proposed one possible geological structure model that shows good correlation between the location of the microseismic activity and the geometry of a pop-up structure developing in a left-lateral strike-slip setting. The pop-up structure produced a localized zone of contraction that favoured the complexity of the hydraulic fracture. . In the pop-up structure itself, forming the area of high compressive strain, faults may act as barriers for the migration of the microseimic activity.