Potential Applications of CO2-EOR In the Middle East

Abstract

Abstract Anthropological CO2 emissions to the atmosphere are identified as a major driver for the global warming effect. Major CO2 emissions sources are located within power and industrial sectors where fossil fuels are consumed to generate energy. With the anticipated escalation of global energy demand, CO2 emissions are also expected to grow. Therefore, reducing CO2 emissions to atmosphere is a fatal issue worldwide. Capturing CO2 from emissions sources and injected into safe geological places for storage shows a practical mitigation strategy through CO2 Capture and Storage (CCS) practices. In CCS projects, several options are available for CO2 storage such as subsurface aquifers, coalbed bed methane formations, or depleted oil and gas reservoirs. Alternatively to these storage places, CO2 can be utilized to enhance oil production from mature oil reservoirs. Utilization of CO2 in enhanced oil recovery techniques (EOR) is a well known practice in oil industry. Therefore, synchronizing between the objectives of storing CO2 and enhancing oil production to meet global demand can be achieved through CO2-EOR projects. The giant oil reservoirs in the Middle East represent potential places for CO2-EOR projects. In this paper, oil reservoirs located in the Middle East are selected to evaluate the potential of CO2-EOR projects in the region. These reservoirs were subjected to CO2-EOR screening where the fluid and rock properties are compared with a well known criteria. Furthermore, an analytical model is used to predict the performance of CO2-EOR in these reservoirs. The results showed that implementing CO2-EOR practices would enhance the oil recovery while storing a considerable amount of CO2 in these reservoirs. Introduction Records of earth surface temperature show an increasing trend in the recent years. Figure 1 shows a history of the annual average of the earth surface temperature during 1880–2008(1). During the last century, the annual average of earth surface temperature increased by 0.74 °C. Many researchers define this growing trend as Global Warming Effect which is a result of an increase in the concentrations of some gasses. These gases, which are known as Green House Gases (GHG), include mainly Carbon Dioxide (CO2), Methane (CH4), and Nitrous Oxide (N2O). According to the global warming theory, GHG allow sunlight to enter the atmosphere freely; however, they absorb the heat from the reflected sunlight. The annual average of earth surface temperature would be about (-19 °C) rather than the present average of 14 °C without GHG effect (2). However, increasing GHG concentrations in the atmosphere allows for more heat absorption and ultimately a rise in earth surface temperature. Table 1 shows the concentrations of the main GHG in the atmosphere (3) with CO2 representing more than 99%. The role of each gas in the global warming phenomenon is based on gas heat retention capacity, therefore; the contributions of GHG to the global warming effect is defined by the Global Warming Potentials (GWP) which represent the ratio of heat retention capacity of a specific GHG to that of CO2 (4). Table 1 shows the concentrations and contributions of each GHG. CO2 contributes to more than 73% of the global warming effect followed by N2O (18.96%) and CH4 (7.09%).