Using 3-D seismic data to estimate stress based on the curvature attribute integrated mechanical earth model

The current state of the technology for unconventional gas and oil development integrates geology, geophysics and engineering into a comprehensive reservoir description. To construct a mechanical earth model (MEM) which takes the geological structure influence into account, we introduce the curvature attribute to express the horizontal strains and extend the classical uniform horizontal strains MEM. The horizontal strains are derived based on the theory of plates and depend on the curvature attributes which reflect the geological structure influence. To take seismic data into the unconventional reservoir characterization, we design a geophysical workflow to estimate the in-situ stress. Amplitude Versus Offset (AVO) inversion produces the elastic parameters and the finite-difference method calculates the curvature attributes. The Bowers' method computes the pore pressure and the in-situ stresses computed from the well-log data are used for the calibration. Real data from the shale gas pilot development areas in the Zhaotong National Demonstration Zone are used to demonstrate the method and compare the new MEM results with the MEM modelling technique results. The curvature attribute integrated MEM shows its advantage.