Analyses of thermal disturbance and formation damages during carbon dioxide injection in shallow and deep reservoirs

Understanding the behaviour of CO2 during sequestration activities is very important as its phase and properties may change, affecting CO2 temperature leading to inaccurate temperature prediction. This inaccurate prediction may influence oil recovery and storage activities. In this paper, an analytical solution is presented to estimate CO2 temperature profile in a wellbore, factors affecting it, and formation damages caused due to heated CO2. For this purpose a simulator is developed by solving the proposed analytical solution and using experimentally determined specific heat values of CO2 to predict its temperature accurately. When CO2 enters into a reservoir, it may dissolves into water and changes the pH of the media. Then it reacts with the reservoir rock, leading to rock dissolution in near wellbore region and precipitation in far region. Comparison of our results with the field-measured data gives a good agreement at wide ranges of temperature, depth, and injection rate. The results presented in this study shows that deep oil and gas reservoirs are good candidates for CO2 sequestration than shallow reservoirs. [Received: March 26, 2014; Accepted: March 7, 2015]