Hydrocarbon charge assessment of frontier basins – a case study of the oceanic crust of the Moroccan Atlantic margin

Abstract

A string of prominent structural anticlines is located in the deep offshore Atlantic Ocean c. 150 km west of Essaouira (Morocco), possibly forming large traps. However, the basement is inferred to comprise oceanic crust, which raises concerns for source-rock presence and sufficient subsurface temperatures for oil generation. The presented work showcases a hydrocarbon charge assessment approach adapted to the very sparse data context and the specific geodynamic settings of the Moroccan Atlantic margin. Regional 2D basin and petroleum systems modelling was performed to assess possible scenarios of hydrocarbon charge of the deep-water folds, its migration style and timing. Several possible oil and gas generation drivers have been identified for postulated Toarcian marine shale source rocks. These range from simple burial-driven heating to more unique scenarios involving early stage oceanic ridge heating and the effect of the Canary Island hotspot. In particular, the latter might have had a major impact on the oil and gas generation, the migration style and overall accumulated amounts.