In order to improve the global saf sty and reliability level of multi-
phase production systems and to guarantee their economical efficiency,
we need a better understanding and control of hydraulic instabilities
observed at the outlet of multi-phase sea-lines. This may be obtained
through the development of slug flow stochastic models, which must be
able to explain: (a) The generation of the various types of slug leng
th distributions which are observed on experimental data sets. (b) The
evolution of these distributions along the sea-lines up to their outl
ets, where large hydraulic fluctuations may be dangerous for the treat
ment installations. Based on experimental as well as theoretical argum
ents, we present such a model with emphasis on slug generation. We giv
e a detailed theoretical analysis, together with a discussion of the u
nderlying assumptions which justify the introduction of this model.