Younes Noorollahi
University of Tehran, Iran
Title: Sea Water Desalination System Modelling Using Geothermal Heat from Abandoned Oil Well
Biography
Biography: Younes Noorollahi
Abstract
Abandoned oil and gas wells can be used as low temperature geothermal resources for heat extraction from geological formations and have valuable potential that avoids the elevated cost of deep drilling in geothermal projects. In this study, an oil wells in southern Iran were modeled using a 3D technique. The bottom-hole temperature of wells AZ was 138.7°C. The circulating fluid is not in direct contact with the hot rock, as in a double-pipe heat exchanger; thus, heat transfer occurs without mass transfer. The fluid circulates in the well by means of a concentric double pipe. Cold water is injected into the well through the outer pipe, heat transfers from the hot rock to the fluid during injection, and the hot fluid is extracted through the inner pipe. To avoid heat transfer between the outer and inner pipes, extruded polystyrene thermal insulation surrounds the outer surface of the inner pipe Heat transfer between fluid injected into the well and the surrounded hot rock was simulated. Well casing geometry for two real abandoned oil wells was considered. The simulation results were optimized for parameters such as input and output fluid flow rate and temperature. The results showed that, in addition to thermal gradient and mass flow rate, well casing geometry and the size of injection and extraction pipes were essential to the output heat extraction rate and clean water production. Total producible clean and fresh water from well AZ-II was 600 m3/day.