This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper OTC 30864, “Large-Scale Experiments on Slug-Length Evolution in Long Pipes,” by Jørn Kjølaas, Tor Erling Unander, and Marita Wolden, SINTEF, et al., prepared for the 2020 Offshore Technology Conference, originally scheduled to be held in Houston, 4-7 May. The paper has not been peer reviewed. Copyright 2020 Offshore Technology Conference. Reproduced by permission.
The complete paper presents a set of two- and three-phase slug-flow experiments conducted in a 766-m-long, 8-in. pipe at 45-bara pressure. The results show that the mean slug length initially increases with the distance from the inlet but that this increase slows and the mean slug length typically reaches a value between 20 and 50 diameters at the outlet. At low flow rates, slug-length distributions tend to be extremely wide. At higher flow rates, slug-length distributions are generally narrower. The experiments demonstrated that slug flow often requires a long distance to develop.