An Advantage described for by-pass pigs is their ability to widen the possibility of applying two-phase flow pipeline transportation to cases where separator or slug catcher capacity are limited for reasons of practicality or cost. The process of an ongoing procedure in proving the technology before its application is described. A simulation model of the pig dynamics as well as the related two-phase flow behaviour was used to predict performance of the pig. A field trial testing a by-pass pig in a dry gas pipeline was performed and provided friction data for the simulation. Positive prediction results were produced by the model on the mobility of high by-pass pigs in the horizontal as well as the vertical orientation in two-phase flow pipelines and risers. The predicted gains by the by-pass pig in modifying gas and liquid production rates during pigging operation are significant.
Oil and Gas Journal 10/14/1996