*4.1. Method*

In the oil and gas E&P industry, international investors use a wide range of methods and evaluation techniques. Various methods have different results and limitations. Currently, there is no widely accepted method to evaluate and compare different types of petroleum fiscal regimes used in the upstream oil and gas contracts worldwide. Therefore, it is difficult to choose the indicators that can reflect the combined effects of different fiscal systems. This research develops the evaluation method by Luo and Yan (2010). Different indicators—namely, governmen<sup>t</sup> take (GT), front loading index (FLI), and composite score (CS)—are included in this evaluation method. These indicators have been selected due to its comprehensiveness, reflection of the income allocation ratio between IOCs and resource-based country under the combined effects of the fiscal regimes. It takes into account the impact of allocation order due to the time value of money and the time sequence of allocation obtained by different parties. The indicators used in this method can affect the final benefit of the IOCs.
