ELASTIC WAVE VELOCITIES IN HETEROGENEOUS AND POROUS MEDIA

Abstract

Longitudinal wave velocities in numerous synthetic and natural porous media at room temperature and pressure have been measured. Basic characteristics of the measuring device are briefly described. Wave velocities have been found for aggregates of uniform spheres of various diameters both when dry and when saturated with water, brine, organic liquids and plastics. The effect of porosity on the wave velocity through aggregates of glass spheres saturated with plastic has been determined over the porosity range 19%–70%. Experimental measurements have been made of the effect of varying brine‐oil and brine‐gas saturations on the wave velocity through natural sedimentary rock samples. The effect of salinity and temperature on the wave velocity through sodium chloride brines has been redetermined. Results are graphically presented to show experimental relationships between wave velocity, porosity, pore content and matrix nature of sedimentary rocks. Some conclusions are drawn regarding general relationships between these factors based on the experimental results and on theoretical considerations. Through these relationships continuous velocity logs in wells can be interpreted to furnish a measure of formation porosity. Some comparisons are given between porosities derived from continuous velocity logs and found by core analysis.