Structural extension and shortening can play a significant role in basin and petroleum system development. Extension creates accommodation space and may cause rapid burial in the basin given a high sediment supply. Extension can also create favorable traps. Structural shortening and inversion can have variable effects on the basin history. Shortening can impact the thermal regime of the basin through structural thickening, uplift, and erosion (Fig. 1). Basin inversion is commonly known for destroying previous traps created during extension. However, inversion can also creates new traps that may contain petroleum either from secondary migration or later maturation.
Blair Burgreen is investigating the structurally complex East Coast Basin
, which has undergone a sequence of shortening, extension, and basin inversion. While seismic data, well control, and onshore geology provide some constraints to structural reconstructions, uncertainties remain regarding the character of the underlying structures and the degree of shortening. Blair has developed a 2D basin model that incorporates a palinspastically reconstructed structural history, and tests uncertainties related to the timing of structural development.
The structural model shows that the structural regions of the basin have different prospectivities due to distinct uplift and burial histories. This impacts both the timing of critical moment and the total generation of hydrocarbons. Additionally, structural regimes experience distinct model sensitivities to uncertainties from source rock kinetics, timing of structural events, and paleo-heat flow, and therefore need to undergo separate risk assessment.