Study of viscous oil-water-gas slug flow in a horizontal pipe

Slug flow characteristics for viscous oil-water-air are experimentally conducted in a horizontal pipe with a 40 mm ID and 12 m long. Results of experimental pressure gradient are presented, taking into account μo = 0.83 Pa s. Water and air superficial velocities ranged 1.02–2.1 m s−1 and 0.22–1.9 ms−1, respectively. Flow patterns were observed and images captured by using a video camera. New data-sets on such flow that include translational bubble velocity, slug and elongated bubble length, total slug unit length and frequency are experimentally provided. Translational velocity of slug units is measured by means of optical probes and video camera, and compared with modified Nicklin (1962) correlation. Moreover, slug body, elongated bubble and slug unit lengths are measured by optical probe. Statistical analysis was adopted based on measured data of slug length to develop probability density function (PDFs). As a result, a new expression to compute slug unit length in terms of liquid, gas superficial velocities, and pipe diameter was proposed.