Estimates of petroleum and natura1 gas resources vary substantially, both over time and across estimation methods. This paper develops a simulation model of global oil resources to evaluate different resource estimation techniques. Protocols for the Hubbert life cycle and USGS geologic analogy methods are developed and applied to synthetic data generated by the model. It is shown that the Hubbert method can generate an accurate estimate as early as twenty years before the peak of global production, but the geologic analogy approach overestimates the true resource base over the life cycle of the resource. The results show the applicability of simulation and the synthetic data approach to the problem of evaluating forecasting methods.