Analysis and evaluation of interwell seismic logging techniques for reservoir characterization. [Quarterly report], April 1--June 30, 1992

The objective of this three-year research program is to investigate interwell seismic logging techniques for indirectly interpreting oil and gas reservoir geology and pore fluid permeability. This work involves a balanced study of advanced theoretical and numerical modeling of seismic waves transmitted between pairs of reservoir wells combined with experimental data acquisition and processing of measurements at controlled sites as well as in full-scale reservoirs. This reservoir probing concept is, aimed at demonstrating unprecedented high-resolution measurements and detailed interpretation of heterogeneous hydrocarbon-bearing formations. Part of the numerical model task is to investigate the sensitivity of the in-situ rock-physical properties of the formation such as porosity and permeability on three-component seismograms, and the pressure, as well as phase velocity and attenuation. For this purpose we have developed software to simulate synthetic seismograins associated with a point-source (compressional wave), and a point force (shear wave), in stratified fluid-filled porous media. In addition, we have developed software to calculate phase velocity and attenuation from interwell seismic waveforms. To demonstrate the use of these capabilities we present examples to simulate seismograms and dispersion and attenuation curves