Computer Simulation of Laboratory Experiments With Two-Phase Slug Flow Induced Oscillations on a Submerged Flexible Catenary Pipe

Experiments were conducted for the oscillations of a submersed suspended flexible pipe ex]cited by the internal two-phase slug flow of liquid and gas. Computer simulations were carried out with proprietary numerical tools to evaluate suitable modeling methods for pipe oscillations. The experiment was conducted with a pipe set in a catenary configuration inside a two meters deep water tank. Water and air were injected into the pipe at its bottom end with various flow rate combinations, forming horizontal slug flow patterns. The slug two-phase flow generated intermittent loads on the pipe promoting its oscillation. At the same time, cameras monitored the dynamic response of the pipe. Processing the video images frames generated time-history records of the movement of the pipe. In this paper, computer simulations were performed to determine the frequencies and amplitudes of the pipe oscillations, which were compared to those from the experiment. A proper scaling up of experimental results with the support of computer simulations should be helpful for the analysis and design of suspended risers employed in offshore petroleum platforms carrying up oil and gas from petroleum reservoir wells to floating production facilities.