Three oil-water-gas flows experiments have been carried out in a 68 mm ID pipe with a dense gas (simulating high pressure flows) and with oils of different viscosities (1.8–100 cP). Measurements include pressure drop and liquid entrainment using an isokinetic sampling probe. The flow is recorded with a high speed video camera. The tested gas velocities (1–4 m/s) did not give large entrained droplet fractions. The effect of water is to reduce the entrainment and pressure drop. OLGA predicts the pressure drop quite well.
In order to design multiphase transport lines it is important to predict the transport of each phase in the pipeline in particular the liquid accumulation and the pressure drop. In separated flows, droplets can be torn off the liquid layer and be transported as a droplet field in the gas. There are two major flow effects coming from an entrained droplet field in the gas. Firstly, the droplet flow can represent a very large fraction of the liquid transport. Secondly, even when the entrained fraction is low, the droplets can cause wall wetting and thus contribute increasing the pressure drop. 1D flow requires closure relations related to the droplet field and these are usually calibrated to experimental measurements under controlled laboratory conditions. Some of the relevant published works are show in Table 1. Most of these experiments were done using water and air at atmospheric pressure where high gas velocities are needed to obtain liquid entrainment in the gas phase. However, the public domain experimental data available for three phase flow is scarce. The present experiments focus in three phase flow at elevated gas densities. The comparison between the predicted and experimental values (Paras et al (1994), Vlachos et al (1997)) shows a good agreement (max error 20%).