Carbonates – A Challenge for Basin Modelers
Research Consultant and Basin Modeler, Chevron Energy Technology Company, Houston
Our understanding of facies and internal connectivity within carbonate platforms is often inadequate despite the fact that carbonate petroleum systems are wide-spread throughout the world, account for ~50% of world hydrocarbon reserves and have been heavily studied for many years. Petroleum systems modeling routinely used in exploration allows testing different facies distribution / connectivity scenarios and contributes to a better understanding of key uncertainties and reduction of exploration risk. However, if misused or based on insufficient input data, petroleum systems models may generate misleading results and lead to drilling unnecessary dry holes. This is especially true if the resolution of the model is too low or calibration data is sparse.
Regional-scale petroleum systems models of carbonates often miss the critical details such as platform geometry, facies distribution within a platform and high resolution rock flow/seal properties that are required for a proper evaluation of hydrocarbon migration, prediction of pre-drill pressure and estimation of accumulated hydrocarbons. In addition, they typically don’t address syn- and post-depositional factors such as diagenesis and stress history.
For the purpose of this study, a synthetic carbonate platform was built to demonstrate typical problems associated with modeling carbonate petroleum systems and for testing potential hydrocarbon migration and trapping scenarios. It allows simulating petroleum systems which are similar to the Arab and Khuff formations in the Middle East, isolated platforms in Kazakhstan, and others. This presentation will discuss petroleum systems modeling methodology and guide the audience through different low- vs. high-resolution scenarios leading to dramatically different exploration implications.
AAPG Search and Discovery Article #90159©2012 AAPG Foundation Distinguished Lecturer Series 2012-2013.