New Study Re-Rates Bamaga Basin Petroleum Prospectivity
A recently concluded detailed study by leading Australian consulting firm Molyneaux Advisers has revealed the Bamaga Basin is even more prospective than first thought.
The study concluded:
The Bamaga Basin (Q23/P) has structural characteristics consistent with formation in the Carboniferous to Early Triassic period.
Formation in that time period is consistent with offset basins such as the Laura, Galilee, Bowen and further afield the Perth and Bedout basins.
All those basins:
formed in extensional and strike-slip structural environments before and contemporaneous with the break-up of Gondwana.
contain prolific, or hydrocarbon prone, source rocks, stacked reservoirs and proven sealing intervals. The Bowen, Perth and Bedout basins have significant oil and gas discoveries.
Because of the above, and the presence of petroleum surface slicks in the area, the Bamaga is expected to be a hydrocarbon-prone basin with the possibility of a material gas or oil discovery.
Molyneaux Advisers’ analytical process:
Used macro-scale tectonics to understand what the stress history of the Bamaga is likely to have been.
Used knowledge of the stress history to hypothesise likely structural movement.
Looked for evidence of the structural movement.
Used any evidence to constrain timing of phases of basin formation.
With knowledge of timing, identified with confidence likely paleo-environment and hypothesise reservoir/seal/source juxtaposition.
Earlier work isolated the geological interval of interest. The latest study built on the previous work, and integrated macro-tectonics of the Australian continental plate, together with regional tectonics and stress history to better understand the history of the Bamaga Basin and constrain the age of its sediment deposition and fault movement. From this a tectonic model was developed for the Bamaga area.
The study identified the Bedout, Perth and Bowen basins as having the following similarities to the Bamaga Basin:
They formed at a similar time.
At the time of deposition, they were spatially constrained.
Their paleoclimate was similar – temperate environment getting warmer.
They likely had a fluvio-marine depositional setting.
Similar tectonics – specifically, NW-SE directed extension associated with break-up of Gondwana, after initial rifting (with varying intensity and direction, depending upon the area).
The Bedout, Perth and Bowen basins have all had sizeable oil and gas discoveries, with production coming from the latter two. Development of the Dorado oil field in the Bedout Basin is underway.
Considering the Bamaga, in the context of the regional tectonics, palaeogeography and paleoclimate, observations have been made at a play level for the presence/absence of play elements. As a result, it is believed that on the balance of probabilities, all the elements of a successful hydrocarbon play are present in the Bamaga Basin.