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Imaging Paleocene and Jurassic Prospects within the Porcupine Basin, Ireland: A Case Study
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, Second EAGE/PESGB Workshop on Velocities, Apr 2019, Volume 2019, p.1 - 3
Abstract
We present a case study and outline the workflow used to process 5500 km2 of new seismic data in the Porcupine Basin area of the Celtic Sea. Key processing challenges include the imaging of faults in the Jurassic interval, volcanic sills and the high-velocity Cretaceous chalk. In addition to these processing challenges, several shallow-gas pockets and channels with variable-velocity infill require detailed depth-velocity modelling to resolve deflections in the underlying sediments. A depth velocity model building workflow is presented which incorporates FWI along with high-resolution image-guided tomography to produce an accurate model for prestack depth migration. Improved imaging of the complex and potentially prospective structures found within the Porcupine Basin is achieved. Detailed anomalies such as shallow channels and gas clouds are corrected with a combination of high-resolution tomography and FWI, which gives increased confidence in the positioning of events along the underlying sediments.