MODULUS AND PERMEABILITY VARIATIONS DURING AIR-WATER FLOW IN SHALEY SANDSTONES

Static deformations and simultaneous measurements of P- and S-wave velocities and air and gas permeabilities for dry, brine-saturated, and partially saturated shaley sandstones from a fluvial-deltaic depositional environment are reported and discussed. Correlations between measured elastic response and petrographic analyses of this material are explored. Variations in velocities for dry specimens are generally consistent with reported behavior in shaley sandstones, but systematic variations of dynamic shear moduli with quartz cement are also observed. Partially-saturated specimen behavior is effectively the same as that for brine-saturated specimens. Saturated behavior shows similar correlations with formation properties as those identified in previous studies of shaley sandstones.