Effect of Particle Size and Liquid Viscosity on Erosion in Annular and Slug Flow

Abstract

Erosion measurements in multiphase slug and annular flow regimes have been made in a horizontal 76.2 mm (3-in.) diameter pipe. These flow regimes are selected since they produce higher metal losses than other flow regimes, and they also occur for a wide variety of operating conditions. Experiments are performed with superficial gas velocities ranging from 15.2 m/s (50 ft/s) to 45.7 m/s (150 ft/s) and superficial liquid velocities ranging from 0.46 m/s (1.5 ft/s) to 0.76 m/s (2.5 ft/s), for liquid viscosities of 1 cP and 10 cP. Three different sand sizes (20, 150, and 300 μm sand) were used for performing tests. The shapes of the sand are also different with the 20 and 300 μm sand being sharper than the 150 μm sand. Erosion measurements are obtained using electrical resistance (ER) probes which relate the change in electrical resistance to the change in the thickness of an exposed element resulting from erosion. Two probes are placed in a bend and another probe is placed in a straight section of pipe. The probes in the bend are flat-head probes, and they are placed flush with the outer wall in the 45 deg and 90 deg positions. The probe in the straight pipe is an angle-head probe which protrudes into the flow with the face placed in the center of the pipe.