Experimental investigation of oil-water two-phase flow in horizontal pipes: Pressure losses, liquid holdup and flow patterns

Flow experiments have been conducted for oil-water two-phase flow in a horizontal 5.08 cm ID flow loop at a length to diameter ratio of 1311. The fluids were light Malaysian waxy crude oil from the offshore Terengganu (ρo=818 kg/m3, µo=1.75 mPa s and wax content=16.15 wt%) and synthetic formation water. The water-cut was varied between 10 to 90% at nine mixture flow rates of 2.0 to 16.2 cm3/s. Measuring the changes in pressure drop and liquid holdup at different flow rates of oil-water two-phase flow, a new flow pattern was identified. Strong dependence of the oil-water slippage on the minimum flow rate was observed. The highest pressure drop of 11.58 kPa was obtained at maximum flow rate of 16.21 cm3/s and oil fraction of 0.9; while the lowest pressure drop of 1.31 kPa was recorded at the lowest flow rate of 2.03 cm3/s and water fraction of 0.9. The experimental results could be used as a platform to understand better a more complex case of gas/oil/water concurrent flow in a pipeline.