Multiphase flow simulations using commercially available software programs have been performed to replicate bypass pigging field tests with the objective of assessing the simulators' suitability for predicting the outcome of field bypass pigging operations.
Design Engineers rely on the accuracy of software programs for the design of slug catchers which are frequently large and costly. Bypass pigging has been proposed as a means of limiting/reducing the required size of slug catchers and thus there is a need to assess and possibly improve modeling in this area. The work performed compares the results of the simulation programs used and is relevant for slug catcher design and pipeline operation.
Simulation results (backed with field data) agree on the benefits of using bypass pigs – lower slug catcher volume required, less/no need to reduce production to manage pig speed, less downstream process perturbation during pig arrival.
Liquid arrival profile at the receiving facility is central to the assessment of bypass pigs as it is expected (and noted in previous works) that liquid arrival rates are more manageable. This work however focused on a gas condensate pipeline flowing fluid with non-negligible water content and results show that the arrival profile of the water phase is different from that of the condensate phase therefore there remains a significant water slug arriving with the pig which to an extent could limit one of the possible benefits of using the bypass pig.
