3D seismic characterization of fractures in a dipping layer using the double-beam method

Abstract

The characterization of natural and induced fractures, in terms of fracture orientation, fracture spacing (or density), and fracture compliance, is critical in reservoir development. Given the multiscale nature of the fracture distribution, the commonly used effective anisotropy assumption may not be valid. The recently proposed double-beam method to characterize the fractured reservoir has the potential to invert for the spatially dependent fracture network information for a horizontal reservoir layer. However, the inverted results can be biased if the fractured reservoir layer is dipping. As a result, it is essential to estimate and include the dip-angle information of reservoir layers in applying the double-beam method. We used forward modeling to demonstrate the bias, and we developed a new method to correct for the error caused by the reservoir layer dip angle. For a dipping layer, our new method can correctly invert for the fracture parameters, including the fracture orientation and fracture spacing.