EXPLORE CARDIFF UNIVERSITY
Supervisors:Joe Cartwright, Tiago Alves (Cardiff University), Frank Peel (BHP Billton).
One of the least understood aspects of petroleum systems is hydrocarbon migration. It is generally thought that migration occurs via the pore network in sediments or via fracture networks, but little is known of how these small scale processes aggregate to the larger scale, and how large fluxes of oil or gas exit the zone of generation and cross large thicknesse of often very low permeability strata to reach the trap. This project aims to characterize the larger scale patterns of hydrocarbon migration by tracking ‘batches’ of hydrocarbon fluids on seismic data. Hydrocarbons are visible on seismic data in some cases through their impact on the bulk physical properties of the sediments through which they are migrating. It is now possible to image an entire migration network and hence derive clues about how fluid flow occurs on a basin scale. This revolutionary technique is in its infancy, and this project will play an important role in defining the best approach to this novel analytical approach to studying fluid flow. Using a combination of 3D seismic and well data, the methodology will be to describe the habitat of hydrocarbon occurrence in a number of basins in contrasting tectonic settings. The stratigraphy and structural geology of the migration pathways will be classified, and the type of ‘plumbing’ will be correlated with the tectono-stratigraphic context. The migration pathways will be assessed through a spatial analysis of potential leakage points or avenues. These are likely to include a combination of structural features such as faults, sandstone intrusions, mud volcano conduits and stratigraphic contacts such as unconformities. The results will provide critical new insights that can inform future decision making regarding the most suitable traps for hydrocarbons, and may also inform those working with carbon capture and storage.