Pipe Dynamic Load Analysis for Transient Multiphase Flow

Multiphase flow regimes such as liquid slugging in gas flow or gas blow through in liquid flow can produce high thrust forces particularly at elbows. In addition, a frequently neglected issue is the potential pipeline collapses caused by a unique multiphase condition of column separation. This paper presents the methods in calculating resistive force on elbows and summarizes the components of the thrust load produced by either pressure or momentum changes. This important distinction seems to be important in understanding the real causes of the pipe dynamic loads and consequently, in the design of the structural support for the pipe system. The second part of the paper focuses on the evaluation of pipeline collapse due to negative internal gauge pressure produced during column separation. The results presented in the paper provide guidance and sense of magnitudes on dynamic pipe loads experienced in transient multiphase flow.