Evaluation of Alternatives to Easy%Ro for Calibration of Basin and Petroleum System Models

Abstract

Understanding degree and timing of thermal maturation is critical for the evaluation of petroleum systems on hydrocarbon prospectivity. However, basin thermal history is one of the key uncertainties. Vitrinite reflectance is one of the most common measurements used to evaluate thermal maturity. We tested and calibrated different published and new vitrinite reflectance models to assess the impact on timing of maturity and hydrocarbon generation. We compared Easy%Ro, its update Easy%RoDL, and Basin%Ro using 1D basin and petroleum system modelling on several wells from the Alaska North Slope. In this study area, Basin%Ro and Easy%RoDL show significant improvements for calibration against vitrinite reflectance profiles that show the characteristic dogleg structure with different rates of increasing maturity. Based on these results, we recommend consideration of several vitrinite reflectance models for thermal calibration and their impact on degree and timing of maturity and the assignment of thermal boundary conditions. In particular, this is important for evaluation of timing of hydrocarbon generation and expulsion related to trap formation. It is not yet certain whether there is a universal algorithm for vitrinite reflectance maturation in humic kerogen and, if not, the relationship between depositional conditions and variations in the algorithm is unknown.