Maximize Asset Utilization by Effectively Identifying and Removing Bottlenecks

Abstract ADNOC Gas Processing Ruwais NGL Fractionation plant receives and fractionates the NGL produced in upstream gas processing plants. After operation of newly designed upstream NGL plants, composition of NGL feedstock has become richer in Ethane and Propane. Consequently, nameplate capacity were reduced by~25%. In view of future increased NGL production, nameplate capacity of fractionation trains needs to be re-instated. Alternatively, a new fractionation train needs to be installed to accommodate additional NGL. To explore the opportunity for maximum utilization for existing trains, in line with the ADNOC strategy of enhancing profitability and asset utilization, a technical study was conducted to increase the processing capacity back to original nameplate capacity with lighter NGL composition. This was to identify the potential bottlenecks in the facility and suggest debottlenecking options with a reasonable investment. The Technical study covers the following activities: Simulation: Rigorous process simulation including the licensor units of DEO/Propane amine units Adequacy checks and identification of bottlenecks: Line sizing adequacy check and detailed hydraulic evaluation of the major piping Equipment adequacy check Relief & blowdown and flare system adequacy check Proprietary equipment/design evaluation of licensed units Adequacy check for In-line instruments like control valves, flow elements/transmitters, thermowells Rotating equipment adequacy checks performed with the concurrence from OEMs. Licensor Endorsement: Obtained the endorsement of AGRU licensor (Shell) for the increased flow rate with revised contaminant levels with recommendations of removing identified bottlenecks. Bottlenecks mitigation: Various options for bottleneck mitigation was studied and most optimum solution was selected to remove the identified bottleneck. The study has concluded that current capacity limitation was mainly due to bottlenecks in Ethane loop. Therefore, by mitigating the identified bottlenecks (i.e. replacing lines with bigger size, providing high performance trays, high performance internals, replacing few equipment's with new one etc.), the original nameplate capacity can be re-instated. The study concludes that increased NGL forecasted flow with lighter composition could be processed in existing Ruwais fractionation trains by doing minor modifications (as compared to new train). A capacity increase of ~25% was achieved with minimum investment and requirement of new fractionation train could avoided. If extensive adequacy studies are carried out to identify the bottlenecks, the capacity enhancement in existing facilities can be achieved with minimum investment and major cost for new plants/trains can be avoided.