Modeling orthorhombic velocity perturbations around salt domes in the Gulf of Mexico

Tilted Orthorhombic Model Building with Geomechanics: Theory and Observations

“…is the normal fracture compliance at zero stress, n  is the stress normal to the fracture plane and Cn  and Ct  are coefficients governing the normal and tangential compliance stress sensitivity of the given fracture. This notation is consistent with the linearized analysis given bySayers 2006. Given any point location the TTI model in terms of compliance ijkl S , and the stress tensor state ij  express both in the global coordinate, we can express these respectively by…”

“…Following Sayers et al 1995 andSayers 2006 we characterize a cracked/fractured medium using the excess compliance model where the effective elastic compliance of the stress sensitive sediment is given by the excess compliance model to be:…”

“…Bachrach et al 2008 showed that azimuthal velocity variations around salt bodies correlates with the state of stress in the subsurface. Bachrach et al 2008 andRodriguez et al 2014 have also demonstrated how orthorhombic model can be built using third-order elasticity (TOE) which is a linearized approach for computing the stress induced anisotropy. As an alternative to TOE, a rock model formulated in terms of fracture compliances can be used to describe stress sensitivity of the rock elastic stiffness tensor.…”

“…As an alternative to TOE, a rock model formulated in terms of fracture compliances can be used to describe stress sensitivity of the rock elastic stiffness tensor. Sayers 2006 andCollet et al 2014 have shown different method to derive stress dependent rock model which can be used for calculating the elastic stiffness of a stressed medium. In this paper we describe how to compute the stress induced anisotropy for the general case where the stress and the subsurface structure (dip) are not aligned.…”