Process design and energy efficiency analysis of an oil and gas processing plant

Abstract The objective of this thesis is process design to prepare a heat and mass balance and associated equipment list that will process untreated reservoir fluids to allow export of saleable gas and oil in an oil and gas processing plant. Gas will be exported to an existing pipeline, oil to a nearby shuttle tanker. By energy efficiency analysis, some energy saving opportunities has been found such as heat integration, replacing control valves with expanders and improving pumps and compressors adiabatic efficiency and then the amount of power recovered through these opportunities have been calculated. After that by considering water added to the feed stream, gas dehydration unit is needed for gas drying. In this reason, a design of TEG dehydration unit has been done and compared with the energy consumption by molecular sieve dehydration unit. Comparison shows that molecular sieve dehydration unit consumes energy about two times more than TEG dehydration unit does. Furthermore, by designing fractionation unit and introducing dividing wall column, consumption of energy decreased about 33% in comparison with conventional columns. In the final part, some energy efficiency opportunities of pumps and compressors, which are the most energy consuming equipment in the oil and gas industries have been introduced. Moreover, the means of power generation for oil and gas plants have been studied. Most plants use gas turbine for power generation and introduce means of increasing gas turbine efficiency and its performance. In the final part some methods for recovery the low-grade heat, variable speed drive which shows significant energy saving, power recovery turbines and reducing friction losses through pipes have been defined.