Feasibility study and modeling of solar generated steam for heavy oil recovery

Abstract

Solar Enhanced Oil Recovery (EOR) technique is one of the emerging technologies being adopted by exploration and production companies to achieve maximum oil recovery with less project cost and environmental effects. Usually, operators around the world use gas-driven generators to produce huge volume of steam to produce heavy oil reservoirs which are not only expensive but also produces carbon emissions leading to greenhouse gases. However, if this same quality steam can be generated through solar energy both problems can be tackled smartly. Thus, this paper aims to present solar potential for the northern field of Pakistan which is estimated through TRNSYS simulation software. Additionally, total incremental oil recovery is also calculated and compared with the different steam injection scenarios. Therefore, parabolic trough collector method has been selected to generate the required steam to heat the oil and reduce its viscosity. Three injection scenarios have been proposed (12-h injection, 18-h injection, and 24-h injection). All the scenarios have been compared against the base case and the best scenario has been selected based on optimum oil recovery. The results of this study suggest that solar generated steam in all the three cases produced more heavy oil, approximately 10% higher, as compared to the hot water steam injection method. In addition, the water cut has been significantly reduced to 21% which shows the effectiveness of solar generated steam over hot water steam. Moreover, while comparing the three solar generated steam cases, the maximum oil production is achieved through the Generation of Solar Steam with a Long-term Thermal Storage backup (Scenario#2) followed by the 100% Solar Steam Generation (Scenario#1) with only 2 to 3-barrel difference. The result further shows that the higher water-cut values approximately 35% are observed at the base case (hot water injection) in which only the hot water injection is carried out, when compared with all other scenarios. Nevertheless, it is obvious that the solar energy can be a best alternative to produce steam instead of burning the natural gas in Pakistan.