Developing a probabilistic compaction model for the Northern Carnarvon Basin using Bayesian inference

Patrick Makuluni | Juerg Hauser | Stuart Clark

Exhumation affects sedimentary basin evolution by influencing structural, pressure and temperature dynamics, thereby impacting energy resource formation. Compaction-based methods are widely used to quantify exhumation, utilising sonic and porosity data to track sediment uplift from its maximum burial depths. However, uncertainties arise from applying empirical compaction models developed for specific geological regions, highlighting the need for region-specific models. Even such region-specific models contain uncertainties, which can compromise exhumation estimates.

Our study published in Basin Research (Makuluni et al., 2024) developed a probabilistic compaction model for the Northwest Shelf Basins using sonic data from normally compacted and unexhumed shales from the Northern Carnarvon Basin (NCB). The model’s robustness was estimated using MCMC, and uncertainty propagation analysis was employed to assess the impact of model uncertainty on the model’s predictive applications. Our findings highlight the need to refine compaction models for better predictive reliability and informed resource exploration in sedimentary basins.