关键词: 射流清管, 压降系数,    ,  旁通率,    ,  清管器速度,    ,  清管段塞

Abstract: In order to analyze the movement rules of bypass pig and the characteristics of piggenerated slug dissipation, a dynamic bypass pigging simulation for a real deepwater gas field was conducted. The movement characteristics of pig velocity and the piggenerated slug dissipation were analyzed through changing the pressure drop coefficient and bypass fraction. The study shows that the pig velocity turns out to be powerlaw distribution with the change of pressure drop coefficients, and within the sensitive range, a small change of the pressure drop coefficient will lead to a huge fluctuation of the pig velocity. The average pig velocity has the tendency of linear reduction with the rise of bypass fraction, the change of which helps to control the pig velocity. By taking advantage of bypass gases to carry and sweep the liquid loading in front of the pig，the running resistance can be reduced, thus the stick phenomena of the pig at the bottom of the riser is avoided. The existence of bypass fraction makes the piggenerated slug dissipate along the pigging period. With the increase of the bypass fraction, the hold up of liquid in the slug is reduced, and the liquid film zone is prolonged, thus making the piggenerated slug volume decrease remarkably. For the optimization of the bypass fraction, an overall consideration should be given to the reasonable scope of pig velocity variations and the piggenerated slug volume, making sure it's within the processing capacity of a slug catcher.

Key words: Bypass pigging,    ,  Pressure drop coefficient,    ,  Bypass fraction,    ,  Pig velocity,    ,  Piggenerated slug