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Seismic-based geomechanical modeling provides attributes for directional well planning
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, Geophysics of the 21st Century - The Leap into the Future, Sep 2003, cp-38-00203
Abstract
Apart of geostructure, routinely delivered by 3D seismic, estimates of pore pressure, rock fracturing, and triaxial stress<br>are needed for efficient directional and horizontal well planning. We show how 3D distributions of these parameters can<br>be mapped by means of geomechanical modeling based on the use of depth velocity model, created in the course of<br>prestack depth migration and enhanced by azimuthal analysis of interval velocities and angle-of-incidence dependent<br>reflectivity. The anisotropic velocity model is converted into 3-D distribution of the rock elastic moduli, angles of<br>internal friction, rock cohesion, and plastic relaxation constants. Considering the fluid-saturated rocks as an undrained<br>anisotropic elasto-plastic medium subjected to lithostatic and tectonic stresses, and applying a fast Lagrangean code<br>formalism for numerical geomechanical modeling, 3-D cubes of expected pore pressure, intensity of fracturing caused<br>by shear strains, and parameters of principal horizontal components of the stress are created for the area studied – a<br>Middle Priob’e’s oil field in West Siberia.