پرویز حاجیانی

Background: Given the importance of fossil fuels and concerns about the future existence of them and dependent economies, also the difficulty of extraction, because of increasing extraction costs, we analysis the standard energy return on investment. Aim: The purpose of this study is to evaluate energy return on investment and predict future trends of this indicator, in addition to comparison predictive power of Weng and Hubbert models and Logarithnic partial adjustment model and study dynamics of energy return on investment based on logarithmic partial adjustment model is discussed. Methodology: to achieve the aims, we study and evaluate the energy return on investment trend,then predict oil and gas production by Weng model and Hubbert model under ultimate recoverable resource scenario, also predict energy return investment by Weng model with linear extrapolation and study of dynamics of energy return on investment based on logarithmic partial adjustment model. In compare predictive power of Weng and Hubbert Models and logarithmic partial adjustment are used R, Rms, Mae, Mape indicators. Conclutions: In study of the past trend of energy return on investment in periods of 1989-2007, we reached the conclution that at least the equivalent of 4.9 in 2002 and the maximum amount is equal to 60.2 in 2007. Hubbert production forecast model were calculated under the average scienario show the peak of crude oil and natural gas equal to 1070.17 million tonnes in 2067, however the peak of them based on Weng model will be 1122.82 million tonnes in 2087. In comparing Weng and Hubbert models, we conclude that the Weng model has the better predictive power than Hubbert model. We face the descending trend of energy return on investment until 2031 by Weng model and extrapolation method. The result of logarithmic partial adjustment model shows that there is an inverse relationship between energy price index and energy return on investment, also a positive relationship between energy