AN EXAMINATION OF POWER GENERATION FROM ABANDONED PETROLEUM RESERVOIRS USING ORGANIC RANKINE CYCLE

Abstract

Most of the wells were plugged due to a decline in oil and gas productivity, while other wells were exploratory. In cases, Abandoned oil and gas wells contain abundant geothermal energy, which can be retrofitted to a novel geothermal system for different utilizations without high-cost drilling. Thus, recently, some researchers have focused on the evaluation of the performance of thermal energy extraction from Abandoned oil and gas wells (AOGW) using Organic Rankine cycle (ORC) systems. Each study applied different working conditions, power scales and cycle configurations; hence an assessment of working fluids is given for specific cases. As a result, no single working fluid has been identified that would meet an entire heat source temperature level. This motivated us to examine various substances for use as working fluids for subcritical ORC systems operating in the medium-temperature range (100– 150°C). This examination was based on the first and second law of thermodynamics, and parameters such as thermal efficiency, first law, and second law efficiency were evaluated. It was demonstrated that the organic fluids examined could be used to generate power using low-temperature waste heat. Organic fluids do not need to be superheated since the cycle thermal efficiency remains approximately constant when the inlet temperature of the turbine is increased. However, using the second law analysis superheating the organic fluids increases the irreversibility. Therefore, organic fluids must be operated at saturated conditions to reduce the total irreversibility of the system. The thermal efficiency of ORC increases when the condenser temperature is decreased. Therefore, using ORC in locations with low ambient temperatures will be more effective. Organic dry fluids (R113, R227ea and isobutane) have better performance than wet fluids (R134a). This is because they do not condense after the fluid goes through the turbine as wet fluids do.