b'Plant & Process | Engineer InnovationThe key outcomes1600In summary, this method demonstratesWH9the significant hydraulic effects disrupted1400gravity flow sections may have on theWH16determination of required wellhead1200 WH10WH15pressures and the selection of safe pipeline section MAOPs.1000 WH17 WH11Flow Rate WH14It further shows the key assumption of800 WH12critical HPVs (located just upstream ofWH5 WH6disrupted gravity flow sections) being out600 WH7 & WH8 WH1of service will always result in theWH3selection of a more conservative and400 WH4therefore safer pipeline section MAOP.200 WH2, WH13, WH18 & WH19The hydraulic modeling approach described enables a two-phase flow0 0100200300400500600700800regime to be modelled in a single phaseTime analysis process. Prerequisite for thisFigure 7: Wellhead flow rate versus time approach is the ability of the software to accommodate hydraulic disruption as found in gravity flow sections.550By back feeding the downstream500 Wellhead 7 - HPVs Offpressure and forward feeding the wellhead flow rate, it has been450demonstrated the highly adaptable400Pressure at Node Level Pressure at Node Level Simcenter Flomaster software canWellhead 5 - HPVs Offsuccessfully accommodate these350disruptive gravity flow sections. 300Wellhead 7 - HPVs OnThe advanced functionality of Simcenter 250Flomaster software for water gathering system modeling will result in significant200time savings and enable the designer toWellhead 5 - HPVs Onconcentrate his efforts on system150optimization work with a high degree of certainty.100 0100200300400500600700800Time A complete downhill water gatheringFigure 8: Wellhead pressures with and without HPVs in service system analysis enables the optimization of pipeline diameter. For example his showed sensitivity600modeling of the main trunkline diameter versus wellhead pressure.580Other pipe section diameters may also560be worth further optimization.540Trunkline Base Size 100%Acknowledgements 520The author expresses gratitude to the500peer reviewer Pedro Milano, PrincipalTrunkline One Size Smaller Dia 88%Process Engineer of Arrow Energy, who480provided valuable input into this paper460based on his extensive design experience440with CSG gathering systems. The author further extends his gratitude to Chris420 Trunkline One Size Larger Dia 112%Peddy from Wood for his guidance. n 4003800100200300400500600700800Time Figure 9: Wellhead WH7 pressure for various trunkline diameters 53'