Managing Liquid Accumulation in Large Diameter Gas-Condensate Pipelines

摘要

Large diameter gas-condensate pipelines are rarely operated below their minimum turndown rate specifiedrnduring design. However there are circumstances where operations at low flow rates are necessary, such asrnpartial shutdown of downstream facilities, which may be planned or in response to abnormal situations.rnAt low flow rates, large liquid volumes are likely to build up in pipelines and limited time is availablernbefore production needs to be turned up or stopped to manage liquid surges on ramp-up or restart. Thisrnpaper describes three events where large diameter two-phase (gas and condensate) and three phase (gas,rncondensate and aqueous phase) offshore pipelines were operated for extended time periods below theirrnnotional minimum turndown rate. For each event, an operating strategy was developed to manage liquidrnsurges in receiving facilities. This strategy is described and analyzed through comparisons between fieldrnmeasurements and dynamic multiphase flow simulations.