In this work, the issue of unconventional resources assessment has been addressed by means of Petroleum System Modelling. In particular, in order to estimate the in-place resources, it is shown that it is critical to be able to evaluate the processes of generation, expulsion and retention in the source rock.
Eni's proprietary software e-simbaTM is able to compute the amount of hydrocarbons generated, expelled by and retained in a source rock, given the thermal and pressure history of the basin and a geological-geochemical characterization of the source rock.
The model is based on the Arrhenius law for the description of the reactions from kerogen to hydrocarbons, on the Darcy law for the expulsion of the generated hydrocarbons out of the source rock and on a complex sequential model for retention. In this work, a brand new workflow for the evaluation of unconventional in place resources has been applied, through the use of e-simba™ technology.
The presented workflow can be applied both in unconventional and in conventional plays, as it allows a better prediction of generation, retention and expulsion processes especially with a multicomponent approach.
The prediction of adsorbed/expelled amounts as well as of the sweet-spot locations can be greatly improved by an accurate simulation of all relevant processes but even more by a robust calibration of model parameters to available data. Thanks to the data relative to source rock desorption potential, which are available in unconventional studies, the calibration can be directly performed considering modelling results.
This allows to reduce exploration risk and to improve Petroleum System Modelling prediction capabilities.
