Fluctuations in the oil global market has been a critical topic for the world economy so that analyzing and forecasting the conventional oil production rate has been examined by many researchers thoroughly. However, the dynamics of the market has not been studied systematically with regard to the new emerging competitors, namely unconventional oil. In this paper, the future trend of conventional and unconventional oil production and capacity expansion rates are analyzed using system dynamics approach. To do so, a supply-side modeling approach is utilized while main effective loops are modeled mathematically as follows: technological learning and progress, long and short-term profitability of oil capacity expansion and, production, and oil proved reserve limitations. The proposed model is used to analyze conventional and unconventional oil production shares, up to 2025, under different oil price scenarios. The results show that conventional oil production rate ranges from 79.995 to 87.044 MB/day, which is 75-80 percent of total oil production rate, while unconventional oil production rate ranges from 19.615 to 28.584 MB/day. Simulation results reveal that unconventional oil can gain a considerable market share in the short run, although conventional oil will remain as the major source for the market in the long run. (C) 2015 Elsevier Ltd. All rights reserved.