Patent ID: 8553498
Filing Date: 2013-10-08
Classification: G01V

Abstract:
1. A ray-based, centroid frequency shift Q tomography method for reconstructing a subsurface Q model from seismic data measured by receivers in a survey using a seismic source, comprising: selecting a mathematical function to approximate the seismic source's amplitude spectrum, and using this to calculate the spectrum's centroid frequency shift due to earth attenuation, and relating said centroid frequency shift to attenuation by a line integral along a ray path connecting the seismic source to a receiver, said attenuation being represented by the reciprocal of quality factor Q, and solving for Q or 1/Q by iterative, linear optimization using a computer, wherein the optimization has box constraints to keep estimated Q values between an upper limit and a lower limit, which limits may be constant or may vary with position.