Abstract Defining the size and shape of hydrocarbon traps is a critical component in estimating the economic value of potential and existing oil and gas fields and is, therefore, a key business risk. Structural traps, defined by fault and fold geometries, form the most common type of hydrocarbon trap, the size estimates of which are based on interpretation of subsurface data, most notably seismic imagery. Interpretation of seismic image data is uncertain, as the subsurface images have limited resolution and quality; in 2D datasets the imagery is spatially limited and the interpretation requires interpolation between images. Here we present data from top reservoir maps created by eight interpretation teams, each of which interpreted a grid of 2D seismic sections at a regular spacing of 1 km, over a 220 km 2 area. The resultant maps are compared for interpretation variability. Fault statistics have been generated for each map and compared with analogue datasets to aid in the identification of anomalous interpretations, and to create a likelihood rank for each map. The structural traps identified by each team are compared, and the two largest traps are assessed for their potential trapped hydrocarbon volume. An initial volume and a corrected volume, accounting for potential fault seal breach by reservoir–reservoir juxtaposition across the trap-defining faults, are calculated. The integrated analysis of the multiple interpretations: (a) captures the interpretational uncertainty, (b) determines the likeliness (or risk) of each interpretation being valid, when compared with analogue datasets and (c) assesses the impact of each interpretation on the economic viability of potential prospects (defined by structural traps).

Abstract The presence or absence of oceanic crust, the location of the continental-oceanic crust boundary, and how spreading centers within the Gulf of Mexico are separated from each other have been matters of conjecture and debate for the past 20 years and are likely to remain so for the foreseeable future. By combining publicly available topographic, bathymetric, gravity and magnetic data and their derivatives, and by comparing these with analog models from divergent margins across the globe, we suggest a refined model for the opening of the Gulf of Mexico. Rifting, leading to ocean crust formation, and seafloor spreading in this area, propagated from the west during the Middle Jurassic, reaching the eastern Gulf of Mexico by the latest Jurassic/earliest Cretaceous. Many authors have suggested that oceanic crust developed as far east as the Henderson and Florida Plain protraction areas. However, we are of the opinion that eastward from central Lund, the crust can best be described as ‘proto-oceanic’ and, by using the Southwest Indian Ridge as an analog, we can show that ultra-slow spreading oriented obliquely to the principal far-field extensional stress orientations, can lead to the features observed in the potential field data from the eastern Gulf of Mexico. By incorporating the observed data into a global plate tectonic context, we are able to confidently predict the location of oceanic crust in the Gulf of Mexico, as well as the orientations of oceanic fracture zones associated with the opening of the basin.