Understanding Hydraulic Fracture Variability Through Integration of Microseismicity and Reservoir Characterization

Microseismic Imaging of Hydraulically Induced-Fractures in Gas Reservoirs: A Case Study in Barnett Shale Gas Reservoir, Texas, USA

“…Results of the present SMT inversion analysis (Figure 6) showed that the energy propagation fit strike-slip shear mechanism, particularly at high S/P ratios, to shear mechanism that probably dominates the lower S/P ratios with a relative symmetry around S nodal and a good match in low amplitude ratios. In addition, high S/P amplitude ratios are noticed to predominate if shear was the main microseismic mechanism in the selected projects [33]. Actually, despite the fact that S/P amplitude ratio plot does not full moment tensor inversion, but it reflects the nature of directional coverage of the radiation pattern and enables qualitatively the assessment of match between the mechanism model and the observed data.…”

“…This is attributed to disability of spectral analysis to fully consider the radiation pattern and non-shear behavior. Generally, most microseismic events magnitudes in typical shale reservoir fall within -0.5 and -3 Mw but relatively large events 1.0 Mw if the hydraulic treatment approached a fault plane which lead Reference [33] consider hydraulic fracturing as aseismic events. SRV is usually calculated using the dimensions of the 3D seismic cloud that is commonly associated with both measurement uncertainty and tendency towards over SRV estimations [37].…”

“…Compared to earthquake seismology that successfully utilizes seismic moment tensor inversion, the good estimation of moment tensor during hydraulic fracturing operation, even with multiple monitoring wells, remain problematic [11]. For different source mechanism (strike slip, shear, and a mix strike slip-shear), Reference [33] constructed a plot of S/P amplitude ratio of high signal-to-noise ratios signals from different hydraulic fracturing projects at various sites using the azimuth relative to the trend of the main microseismic cloud. Results of the present SMT inversion analysis (Figure 6) showed that the energy propagation fit strike-slip shear mechanism, particularly at high S/P ratios, to shear mechanism that probably dominates the lower S/P ratios with a relative symmetry around S nodal and a good match in low amplitude ratios.…”