Transform-margin model of hydrocarbon migration: the Guyana–Suriname case study

Abstract

AbstractThe study focuses on the Guyana–Suriname transform margin, utilizing well and reflection seismic data. Both datasets allow the permeability stratigraphy to be interpreted. It consists of areally extensive reservoir horizons separated by intraformational shale horizons and erosional unconformities. The youngest strata are deformed by the two generations of gravity glides, which took place fairly late in post-break-up history.Hydrocarbon shows from wells indicate that strata deformed by gravity glides are the only sedimentary packages where the vertical hydrocarbon migration dominates. Clusters of oil and gas shows have random spatial distribution in respective reservoir horizons within gravity glides. The base of the rock volume with dominating vertical migration is determined by the detachment horizon of the gravity-glide system. However, the areas unaffected by gravity glides are dominated by lateral migration, causing zonal distribution of oil and gas shows. Oil shows occur in wells penetrating the proximal margin and gas shows are found in wells penetrating the distal margin in respective reservoir horizons. Both sets are fed by the source rock occurring in the oceanic basin and the adjacent distal margin. The best example of this situation is provided by the Paleocene–Eocene reservoirs.