Liquid droplet entrainment in two-phase oil-gas low-liquid-loading flow in horizontal pipes at high pressure

An experimental study is conducted in a 152.4-mm inner diameter (ID) high-pressure facility to investigate the liquid droplet entrainment in two-phase oil-gas flow in horizontal pipe under low-liquid loading condition. Total of 247 tests are carried out at five different operating pressures, namely, 1.48, 1.82, 2.17, 2.51, and 2.86 MPa. The test fluids are nitrogen and mineral oil (Isopar-L). Superficial oil velocity (v_SL) ranges from 0.01 to 0.05 m/s, while superficial gas velocity (v_Sg) ranges from 1.6 to 16.7 m/s depending on the operating pressures. An isokinetic sampling system is used to measure the entrained droplet flux at three different vertical positions in the gas phase. A high-speed video camera is used to visually observe and estimate the onsets of entrainment. This paper provides a unique entrainment data set for two-phase flow in a large diameter pipe at high operating pressure. The experimental data are analyzed to evaluate the effects of high operating pressure and superficial velocities. It is found that the entrainment fraction increases with the operating pressure. In addition, predictions of ten correlations for two-phase entrainment fraction are compared with the experimental data to evaluate the performances. The results show that these correlations over-predict the entrainment fraction data from this study.