The influence of in-situ stress and geomechanical properties on P-wave reflection coefficients for HTI media

Abstract

Estimation of stress and geomechanical properties of anisotropic fractured reservoirs is a critical issue during oil & gas field development. Since the seismic data is sensitive to these properties, studies of the variation of Pwave reflection coefficients with azimuth in a horizontal transverse isotropic (HTI) media can be applied to obtain fracture properties and extended to estimate the in-situ principal stresses. Therefore, considering the Rüger reflectivity approximation for HTI media, we employ a seismic to geomechanics relation through the Linear Slip Theory (LST), based on a simplified Hooke's law for HTI media, to estimate fracture properties. Finally, we derive an anisotropic poroelastic horizontal stress model in order to analyze the influence of in-situ principal stresses in the AVO response for an ISO-HTI interface at the symmetryaxis and isotropy planes.