Including poroelastic effects in the linear slip theory

J. GERMÁN RUBINO; CASTROMÁN, GABRIEL; T. MUELLER; L. MONACHESI; FABIO I. ZYSERMAN; K. HOLLIGER

GEOPHYSICS

SOC EXPLORATION GEOPHYSICISTS

Lugar: Tulsa, OK; Año: 2015 vol. 80 p. 51 - 56

0016-8033

Numerical simulations of seismic wave propagation in fractured media are often performed in the framework of the linear slip theory. Therein, fractures are represented as interfaces and their mechanical properties are characterized through a compliance matrix. This theory has been extended to account for energy dissipation due to viscous friction within fluid-filled fractures by using complex-valued frequency-dependent compliances. This is, however, not fully adequate for fractured porous rocks where wave-induced fluid flow between fractures and host rock constitutes a predominant eismic attenuation mechanism. In this letter, we propose an efficient approach to incorporate wave-induced fluid flow effects directly into the linear slip theory via a complex-valued, frequency-dependent fracture compliance. The methodology is validated for a 1D medium characterized by a regular distribution of planar fractures, for which an analytical expression for the complex-valued normal compliance is determined in the framework of quasi-static poroelasticity. There is good agreement between synthetic seismograms generated using the proposed recipe and those obtained from comprehensive, but computationally demanding, poroelastic simulations.