Imaging Paleocene and Jurassic Prospects Within the Porcupine Basin, Ireland: A Case Study

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, with a triple-source acquisition configuration.

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 processing flow is presented to address these imaging challenges, along with those posed by the triple-source acquisition configuration. This flow includes deblending, multiple attenuation, regularisation and incorporated FWI along with high-resolution image-guided tomography to produce an accurate velocity 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.