Experimental characterization of synthetic porous orthorhombic fractured medium: A physical modeling approach

The study of fractures in subsurface is very important since they are, in some cases, the main conduits for hydrocarbon flow in a reservoir. There are many ways to study the behavior of seismic waves in different fracturing conditions, including the use of physical modeling. This method allows, among other approaches, the analysis of the behavior of seismic wave properties in complex fractured media, such as media with orthorhombic symmetry. In this work we performed ultrasonic measurements on fractured physical models with orthorhombic symmetry from which we analyzed the behavior of elastic velocities and anisotropy parameters for different number of fractures. The presented results show the efficiency of the construction methodology used in the study by presenting P- and S- wave velocity values consistent with the theory for an orthorhombic medium. It was observed that for the direction perpendicular to the fracture system the values of P and S-wave velocities were the smallest for each model, and that the velocities decreased as the number of fractures increased in all models. Furthermore, most of the ∊ and γ values show a decreasing behavior as a function of the decreasing number of cracks, being the trend curves of ∊ linear and most of the trend curves of γ quadratic. Additionally, all the ∊ parameters presented a high correlation with the γ parameters for a small number of fractures, lower than 5.