SEGJ Technical Conference

Strain anomaly detection in a digital core sample using numerical seismic waveforms

Abstract To elucidate the relationship between seismic attenuation phenomena observed in various seismic methods at widely different frequencies and fractures developed in carbonate reservoirs and to elucidate the rock physics mechanism responsible for those phenomena associated with fractures, we propose a novel method to measure dynamic properties of weak zones caused by fractures in a broadband frequency by calculating strain anomaly from seismic waveforms. The characteristic of our proposed method is that we conduct 3D numerical simulation in a broadband frequency on a digital core produced by an X-ray computed tomography (CT). We describe the concept and workflow of our proposed method and then apply the proposed method to core plugs acquired in an Abu Dhabi oil field. We demonstrate that local strain anomaly can be detected by using seismic waveforms whose wavelengths are larger than the core samples. Furthermore, from the viewpoint of random media study, we may be able to propose new concept heterogeneity-induced strain which may disturb the low-frequency laboratory measurement.