ROCK PHYSICS MODELLThG OF LOW TO INTERMEDIATE POROSITY SANDSTONES

Abstract

For quantitative analysis and interpretation of the reservoir quality tight sandstone reservoirs it is essential to understand the seismic properties of low-to-intermediate porosity gas-saturated sandstones (Avseth et al., 2014). Tight sandstones have generally undergone severe mechanical and geochemical compaction processes that cause a large reduction in their original porosity from the time of their deposition. The elastic properties of low-porosity rocks depend more on the specific pore structure than on the actual porosity and, in general , the bulk modulus within the crack-like porosity dominates the overall fliud reposonse. Pore fluid effects are modelled using gassmann ( 195 1) model. It is proposed to study the variation of elastic moduli and seismic wave speeds of low to intermediate porosity sandstones using the theories mentioned above. Also a comparison between theoretical and empirical results is carried out