Another specialist module in LogIC is full sonic waveform analysis. This module is used primarily for shear wave transit time, which can be estimated using a number of algorithms. Full waveform sonic is in active development with our users to increase the range and usefulness of the analysis.
Sonics are run in almost every well, and the value of acquiring and processing array data is only now becoming generally appreciated. Standard processing allows calculation of compressional, shear and Stoneley velocities, data which are used for standard formation evaluation, calculation of geo-mechanical properties and seismic applications. As usual in LogIC, the emphasis of the sonic waveform analysis is on interactivity. LQC, filtering and validation are all essential preliminaries to successful processing, and point-and-click visualisation of waveform sets is the starting point, especially for dipole modes and in slow formations.
Coherence analysis is by semblance, nth root stack and correlation methods. Various resolutions and waveform combinations can be used. STC plane visualization allows tracking and identification of the various arrivals. There are standard and user-defined equations for geo-mechanical properties - Poisson’s ratio, shear, bulk and Young’s moduli, strength estimates etc. Power spectrum analysis allows for qualitative permeability estimation