GEOPHYSICS: This issue of GeophysicsThis issue of Geophysics

Abstract

Grech et al. use the first arrivals from a multi-offset VSP to determine the anisotropy parameters by traveltime inversion. The authors demonstrate the application of these parameters during anisotropic PSDM for enhanced depth imaging. Shen et al. introduce a technique to AVO and FVO attribute estimation in the frequency domain and demonstrate the application of these attributes to the detection of fracture orientation in a carbonate reservoir in the Maporal field of southwestern Venezuela. They also show that reservoir heterogeneity has an important effect on AVO signatures and should be considered in fractured reservoir characterization. Slater and Reeve propose that electrical geophysics methods are excellent tools for the investigation of the stratigraphy and hydrogeology of peatland systems and the related controls on vegetation communities observed at the surface. Whereas GPR and IP imaging are appropriate for determining peat and underlying lake sediment thickness, resistivity imaging is valuable for investigating the mineral basement, which exerts a strong control on peatland hydrogeology. Soroka et al. demonstrate how 3-D AVO can be an effective tool for identifying potential missed reserves in old producing fields. The advantages of 3-D over 2-D AVO are discussed. Valuable acquisition and processing lessons learned in this early onshore 3-D AVO project are presented for future reference. Berryman et al. present a new synthesis based on ideas of Gassman and Biot that uses compressional and shear wave velocities in a scheme that is much simpler to understand and apply, yet yields detailed information about porosity and fluid saturation magnitudes and spatial distribution. The density and the Lame elastic parameter λ are the two parameters determined from seismic velocities that also contain information about fluid saturation, and this observation leads to concepts for two types of λ -diagrams for evaluating partial and patchy saturation in reservoirs. Prasad shows how P …