A three-stage scenario based operational performance test approaches for production capacity enhancement: Case study on the 5th refinery of South Pars Gas Complex in Iran

In this work, the possibility of capacity enhancement in the South Pars Gas Complex of Iran has been studied. Mass balance is studied and data validation and reconciliation have been carried out in 5th refinery of South Pars Gas Complex in order to achieve the reliable data of the plant. Then the possibility of capacity increase has been studied, taking into account the important parameters such as alteration of the plant pressure profile. Calculation of the key parameters for different equipment at higher feed rate, specified the unit of operations which may have trouble during the capacity enhancement. The performance of export gas compressors, dehydration unit and High-Integrity Pressure Protection System (HIPPS) has been anticipated to be the obstacle of this project according to the results of design basis review. In order to increase the feed rate the operation at constant inlet pressure is considered while the final stage pressure decreases as it is safe procedure for the plant. Then performance test has been carried out to monitor the changes in the plant. Three methodologies were designed and evaluated for implementing the performance test, and the stepwise procedure has been carried out successfully. During the performance test, the feed rate has been increased in three consecutive steps by 4.5%, 3% and 2.5% respectively. The operation of key equipment such as turbo expanders, exports and refrigerant compressors, dehydration beds, columns and filters, have been examined by taking samples from inlet-outlet streams such as feed gas, acid gas, lean and rich amine, LPG product. Following the step wised feed rate increase, the performance test was operationally successful and the production capacity of sweet gas in South Pars has been increased about 10%.