The role of stress and fluid saturation on the acoustic response of fractured rock

Standard rock physics models are formulated to describe the behavior of porous sedimentary reservoirs, with clean sandstones being archetypal system; however, many situations demand geophysical monitoring rocks significantly different structures, such as low porosity, fractured reservoirs. Conventional also suggest that these “stiff” reservoirs can be challenging monitor seismically due small fluid substitution effects, but presence fractures leads stress dependence which may leveraged for remote purposes. Using samples from Duperow Formation (dolostone) obtained Danielson test well in Kevin Dome, MT, we conducted ultrasonic and multi-scale structural (profilometry, synchrotron micro-tomography, pressure sensitive film) measurements on naturally core order characterize effects effective acoustic response reservoir a focus particular textural seismic characteristics natural fractures. We find changes yield velocity up 20% attenuation 200%. Measured resolvable, dominate. These provide insight into physical processes controlling general used inform efforts