000			02464nab a2200205 4500
005			20260520000318.0
008			260224s2014 xxu ing
041			_aInglés
245	0	0	_aGeomechanics of hydraulic fracturing microseismicity _bPart 2. Stress state determination
260			_a _b _cnov. 2014
270			_a18/12/2014 ; 16/12/2014
300			_a17 p. ; 2459-2476
520			_aTranscripción del resumen del autor: We investigate the hydraulic fracturing process by analysis of the associated microseismicity. In part 1, we recognized double-couple and hybrid microseismic events and their fault plane orientations. Critical stress (instability) and stress inversion techniques were used to assess fracture activation conditions. In part 2, we apply results from the tensile source model to investigate how activated faults relate to the stress state and geologic setting. We assess potential mechanisms for induced microseismicity including leakoff and diffuse pressurized fracture network flow, stress shadowing adjacent to large parent hydraulic fractures, and crack tip stress perturbations. Data are from the Mississippian Barnett Shale, Texas, and include microseismic events from sequential pumping stages in two adjacent horizontal wells that were recorded in two downhole monitor wells, as well as operations, wellbore-derived stress, and natural fracture data. Results point to activation of inclined faults whose orientation is dominantly northeast–southwest and vertical north–south faults. The activation stress states for a range of modeling scenarios show stress rotation, decreased mean stress, and increased deviatoric stress. This stress state cannot be explained by sidewall leakoff in the stress shadow region adjacent to hydrofractures, but is consistent with hybrid and shear activation obliquely ahead of pressurized fractures. Information about hydrofracture evolution and operationally related dynamic stress change is obscured by geomechanical heterogeneity that is likely geologic in nature. The most compelling observation is that the most highly misoriented microseismic faults occur in the same vicinity as a carbonate-dominated submarine fan feature that was previously expected to act as a minor fracture barrier.
581			_a11
773	0		_tAAPG Bulletin _g98
942			_cARTICULO
100	1		_aBusetti, Seth _954318
100			_aReches, Ze'ev _954319
999			_c188713 _d188713