Fracture-Induced Frequency-Dependent Anisotropy, Yibal Field, Oman

Fracture size is one of the main parameters that reservoir engineers are interested in due to its importance in hydrocarbon production. We estimate the fracture size using the Chapman (2003) theory of frequency-dependent shear-wave splitting on microseismic data recorded in the Yibal field. The Natih A reservoir demonstrates the largest fracture size and fracture density of 2 m and 0.07-0.23, respectively, as expected for a highly fracture reservoir. In contrast, the Fiqa exhibits moderate fracture density (3%) with fine-scale fractures (<0.1 micrometer in size) as expected for a seal rock. Collectively, the results of frequency-dependent S-wave splitting are mainly controlled by lithology.