The Flow Of Gas Liquid Mixtures In Pipes PDF Download

The aim of this study was to investigate hydrodynamic two -phase (namelywater and air) fluid flow characteristics in helical pipes of low amplitude andstraight pipes of the same internal-diameter and constructional material: theresults for the two pipes have then been compared. One of the objectives was to measure pressure, pressure drop and liquidholdup in the two pipes. These are universal dominant parameters in the oiland-gas industry as they significantly impact on the exploitation andconveyance of crude oil from wells or reservoirs to the process plant, where thecrude is refined. The second objective was to examine applications of thehelical pipe. Experiments were performed on three different helical pipes of internaldiameters 25.4 mm, 50 mm and 100 mm and their straight counterparts. Thesingle-phase preliminary experimental results from the 25.4 mm internaldiameterfor both pipes have shown that both pressure and pressure drop arehigher in the helical pipe than in the straight pipe. The friction factors were alsoevaluated for both pipes and found to be higher in the helical pipe than in thestraight pipe. The single-phase and two-phase experimental results for the 50mm internal-diameter pipes confirmed the conclusions from the preliminaryexperimental results. The two-phase results showed that slug flow occurred inthe straight pipe at certain superficial velocities of air and water, whereas at thesame superficial velocities of air and water, slug flow did not ensue in the helicalpipe - instead bubbly flow was observed. Stratified flow occurred in the straightpipe at very low superficial velocities of air and water but under these sameconditions, bubbly flow ensued in the helical pipe. A section of 100 mm internal-diameter helical pipe was installed at somedistance from a catenary-shaped riser, with a view to investigating theeffectiveness of the helical pipe in mitigating severe slugging. The resultsshowed promise as the section of the helical pipe proved to be successful inreducing the menace of severe slugging. This novel finding is regarded as abreakthrough for the oil-and-gas industry in this respect. This is becausehydrocarbon proven reserves in the off-shore (i.e. deep sea-water) environmenthave been estimated to be close to 60%. All previous research studies over thepast decade to provide solution to the problem posed by severe slugging havenot yielded any appreciable results. This discovery also has the advantages ofreducing the demand on the topside (process) facility and the achievement ofstability of liquid production is resulted from the consequent flow assurance inthe pipeline and riser.