Stratigraphic architecture of the synrift interval in the northern Pletmos Basin, offshore South Africa

Abstract

A revised analysis of the stratigraphy and the order of deposition in the Synrift interval is conducted for the northern Pletmos Basin, offshore South Africa. The study area, spanning 14,330 km2, includes the Superior and Plettenberg grabens. By employing new techniques in seismic stratigraphy, a more accurate identification of sedimentary layers in the basin was achieved, taking into account their seismic characteristics, internal structure, and termination points. The findings primarily focus on two distinct phases of geological activity known as Synrift I and Synrift II. The Kimmeridgian interval of Synrift I has not been extensively explored, and is believed to exhibit petroleum potential, as indicated by the presence of oil and gas shows and the distinctive seismic features of structural closures. Within the Synrift interval, ten separate sequences were identified, each displaying different seismic characteristics and environments of deposition. By utilizing these predicted depositional environments, numerous potential drilling sites were identified within the Synrift interval. Furthermore, it was determined that these sites were supplied with hydrocarbons from three hypothesized source intervals. Consequently, this research enhances our understanding of the potential for hydrocarbon reserves in the northern Pletmos Basin.