Improved hydrocarbon charge prediction by source-rock modelling

Abstract

Predictions of initial source-rock distribution, thickness and quality are key input parameters to quantitative basin models. This article describes a workflow where process-based modelling of deposition and preservation of organic matter at basin scale is performed to provide the input to modelling of hydrocarbon generation and expulsion from source rocks. As the vertical resolution of the depositional- and source-rock models is significantly higher than for conventional basin models, a means of upscaling the source-rock properties is needed when providing these as input to hydrocarbon generation modelling. To illustrate the modelling workflow, an example from the Triassic Kobbe Formation of the Norwegian Barents Sea was used. Two alternative source-rock models for the Kobbe Formation were constructed and discussed. During the modelling process preservation conditions were fine-tuned to better match local well data within the Nordkapp Basin. The second model provided a better calibration both for the source-rock model to the well data and for the secondary migration model to known hydrocarbon accumulations of the Nordkapp Basin.