The main structural styles of the hydrocarbon reservoirs in Oman

Abstract

Abstract The subsurface structural styles vary across Oman. Understanding this diversity has a strong impact on optimizing hydrocarbon exploration and production. This work is an attempt to summarize the main structural features that characterize the reservoir types in different tectonic domains in Oman in order to provide structural constraints on the interpretation of subsurface data, particularly in areas of poor data coverage or quality. In the South Oman Salt Basin, salt halokinesis dominated the deformation style and the orientation of local stresses. This has resulted in a tortuous framework of faults and folds. During the Palaeozoic, simultaneous differential loading of overlying sediments and salt dissolution were the main deformation mechanisms. The regional stresses are more defined in north Oman. Two structural orientations are observed within the Fahud and Ghaba Salt Basins: NW–SE and NE–SW. The first was formed during Late Cretaceous time, whereas the second developed during the Late Cenozoic. Pre-existing faults were reactivated in both tectonic episodes. The deformation within the north Oman salt basins is localized above pre-existing faults. Outside the salt basins, in the Lekhwair and Makarem highs, the faults mainly trend NW–SE. These tend to be uniformly distributed throughout the basins and have uniform orientation, throw and vertical continuity.