Prediction of Slug Length in Horizontal, Large-Diameter Pipes

Abstract

Summary The prediction of slug characteristics for large-diameter pipes is studied with data collected from flowlines in the Prudhoe Bay field in Alaska. A 3-mile [5-km] -long pipeline was fully instrumented with nuclear densitometers, insert turbine meters, flowmeters, pressure and temperature sensors, and separator level indicators. During these tests, more than 19 million data points were collected on 12-, 16-, 20-, and 24-in. [30-, 41-, 51-, and 61-cm] -diameter pipes. These data were used to construct a data base that can be accessed interactively or by FORTRAN applications programs. The data show such slug characteristics as slug length, bubble length, and holdups. Data analysis revealed that the liquid slugs do not maintain a constant length and that the slugs tend to grow as they flow through the pipeline. An existing slug-length correlation was modified with these new data, and a term was added to account for the observed slug growth.