The study of multiphase flow is more difficult and complex in undulatingpipelines due to flow interaction between different pipe sections and influenceof the specific angles being studied. While previous studies (Zheng et al.,1995; Al-Safran et al., 2005) are low angles of hilly pipeline, there is noadequate information on flow characteristics for high angles. The complexity insand transportation in multiphase flow is more aggravated in undulatingpipeline
This paper presents experimental investigations to understand the multiphaseflow characteristics, conditions for slug initiation mechanism that wouldenhance sand transport in undulating pipes and assist pipeline design. Theinvestigations were conducted using a 2-inch (ID=50.24 mm) dip facility whichconsists of a downhill pipeline (−24o), a lower elbow (dip) and an uphillpipeline (+24o).
The slug initiation mechanisms phenomena were investigated. New flow regimeswere identified for different pipe sections using both visual observation andstatistical parameters. Sand transport characteristics in water and air-waterwere studied at different sand concentration. Also, flow condition to transportsand bed deposit at the dip was determined.
Three slug behaviours were observed at the dip: complete stratified flowdownhill with slug initiation at dip; stratified flow (with energetic ripple)downhill with slug initiation and slug growth at the dip; and aerated slugdownhill and slug growth at the dip. This behaviour is different from existingworks on this subject with low angle of inclination.
Solid-liquid-gas flows are commonly encountered in industries such as chemicalprocessing plants, mining of coals and, oil and gas industry. It is apersistent problem in the petroleum industry for many years; most especially inpoorly consolidated reservoir or where hydrocarbon is in the increasing demand. It is quite impossible to produce a sand free hydrocarbon with presence of sandcontrol in place that can prevent sand production with the unprocessedhydrocarbon. However, the alternative approach is to transport sand along withthe multiphase flow hydrocarbon due to factors such as increase in demand ofhydrocarbon and cost to prevent sand production from the reservoir
