Characterization of drilling-related noise and curvelet-based evaluation of seismic-interferometric reflections for imaging of iron-bearing formations in Pilbara, Western Australia

SUMMARY Here we analyse ambient noise (AN) data generated during drilling of exploration boreholes and recorded using a dense array deployed over one the numerous shallow iron-ore mineralization targets in Pilbara region (Western Australia). Drilling drilling-related operations were reoccurring sequence as described by drillers’ field notes, which created rare opportunity to AN time segments when only type technical process was predominantly active. Consequently, most sources did not overlap space. We extract recordings 15-min-long matching time-span single field-note entry identify individually acting associated with specific operations. The temporal variations spectrograms cross-correlations show dependency on few consecutive frequency–amplitude patterns These changes are directly reflected events visible retrieved virtual-source gathers (VSG), implying significant spatial stationarity. Some VSGs represent mixed contributions surface air waves. To remove these arrivals reflection imaging, visually inspect all select stationary-phase specifically for retrieval. This done different receiver configurations inside PilbArray, result, obtain collection containing coherent body-wave reflections. Database inspected is used develop benchmark semi-automatic curvelet-based method accurate parametrization from passive compare imaging quality Common-midpoint stacks manually automatically selected reflectivity consistent obtained active-source related structure hosting iron mineralization. Our results demonstrate capacity seismic interferometry retrieve reflections image They also provide an intermediate step toward automating similar sets.