Maturation & Timing

Basin modeling work recently undertaken by Geotrak showed that the principal heating event that matured the source rocks was the Deccan volcanic event at the KT boundary but also identified several other significant heating events that both pre and post date this event. From the tectonic evolution explained earlier, it is clear that the majority of structures had formed before the generation and migration of hydrocarbons.

This table lists the different heating events identified ranging from the Late Paleozoic to the Late Tertiary Mahe Event. 

Burial history modeling was undertaken on pseudo wells by Geotrak.

In the NE shelf basin it showed that the main phase of structuring is at least as old as the generation event,

In Reith Bank Peak maturities and high generation rates were attained during the Marion event (Early Cretaceous) for the deeper source rocks and during the Deccan event (K-T Boundary) for the shallower ones. Locally, generation from the oldest source rocks may have even preceded the Marion event as a consequence of normal burial. Main phases of deformation and formation of structural traps occurred prior to each of these thermal events.

In pseudo well B, Maturation in the proposed but as yet unverified source rocks occured in several steps. The most important of these was the Marion event, but additional generation also occured during the Deccan event and even the Mahe event. The main phase of structural deformation predates the earliest generation event.

Lastly in pseudo well E, Peak maturities with high generation rates occurred during the Deccan event, although the oldest rocks generated hydrocarbons during the Marion event. Both structural and stratigraphic traps predate the generation events.