Open AccessSEISMIC AND ROCK PHYSICS DIAGNOSTICS OF MULTISCALE RESERVOIR TEXTURES
Author(s) -
Gary Mavko
Publication year - 2004
Language(s) - English
Resource type - Reports
DOI - 10.2172/834112
Subject(s) - geology , permeability (electromagnetism) , porosity , carbonate rock , carbonate , fluid dynamics , attenuation , characterisation of pore space in soil , geomechanics , mineralogy , slip (aerodynamics) , petrology , pore water pressure , seismic wave , seismology , geotechnical engineering , sedimentary rock , geochemistry , mechanics , materials science , genetics , physics , thermodynamics , membrane , optics , metallurgy , biology
As part of our study on ''Relationships between seismic properties and rock microstructure'', we have continued our work on analyzing well logs and microstructural constraints on seismic signatures. We report results of three studies in this report. The first one deals with fractures and faults that provide the primary control on the underground fluid flow through low permeability massive carbonate rocks. Fault cores often represent lower transmissibility whereas the surrounding damaged rocks and main slip surfaces are high transmissibility elements. We determined the physical properties of fault rocks collected in and around the fault cores of large normal faults in central Italy. After studying the P- and S-wave velocity variation during cycles of confining pressure, we conclude that a rigid pore frame characterizes the fault gouge whereas the fractured limestone comprises pores with a larger aspect ratio. The second study was to characterize the seismic properties of brine as its temperature decreases from 25 C to -21 C. The purpose was to understand how the transmitted wave changes with the onset of freezing. The main practical reason for this experiment was to use partially frozen brine as an analogue for a mixture of methane hydrate and water present in the pore space of a gas hydrate reservoir. In the third study we analyzed variations in dynamic moduli in various carbonate reservoirs. The investigations include log and laboratory data from velocity, porosity, permeability, and attenuation measurements