Probabilistic tectonic heat flow modeling for basin maturation: Assessment method and applications

Tectonic modeling is often neglected in the basin modeling workflow and heat flow is most times considered a user input. Such heat flows can, therefore, result in erroneous basin modeling outcomes, resulting in false overoptimistic identification of prospective areas or failure to identify prospects. This is particularly true for areas with limited data control such as frontier basin areas, or deep unexplored plays in mature basins. Three major factors obstruct routinely use. Firstly, because of the focus of most tectonic models on lithosphere scale processes a large range of models, including the McKenzie rift model, fail to take into account effects which are of paramount importance for basement heat flow such as transient effects of sediment infill and erosion, and changes in crustal heat production over time. Secondly, lithosphere tectonic models often fail to allow inversion of basin data, making forward tectonic modeling a cumbersome exercise. Non-vertical sediment movements and 2D and 3D loading effects can play an important role, hampering a unique inversion. Thirdly, lithosphere tectonic models generally fail to aid the user to understand the sensitivity of the model results in terms of basin maturation for permissible ranges of tectonic model parameters and for uncertainties in tectonic scenarios such as absence or presence of underplating or two-layered stretching vs a McKenzie model. For this reason, we have developed a multi-1D probabilistic tectonic heat flow model, which is capable of calculating tectonic heat flows, incorporating a variety of tectonic scenarios. The model is capable of inversion of burial histories, calibrated to temperature and maturity data. Calibration and sensitivity analysis is done through Monte Carlo sampling analysis using an experimental design technique for computational efficiency. The tectonic heat flows can easily be used as input for basin modeling in commercially available 3rd party software. © 2009 Elsevier Ltd. All rights reserved.