Simulation and experimental proof of plug formation and riser blockage during vertical hydraulic transport

作者：van Wijk J M^*; van Grunsven F; Talmon A M; van Rhee C

来源：Ocean Engineering, 2015, 101: 58-66.

DOI：10.1016/j.oceaneng.2015.04.015

• Riser blockage
• Vertical hydraulic transport
• Deep ocean mining
• Flow assurance

In deep sea mining, the vertical transport of excavated material from the seafloor to a vessel at the sea surface is a key process. Stationary flow is preferred, and blockage of the riser would terminate the entire operation.
For a blockage to occur there needs to be accumulation of material, the formation of a solid plug, and the plug needs to exert sufficient friction on the riser wall. The formation of a blockage is a complex chain of events, described in detail in this paper.
The hypothesis presented in this paper on the formation of plugs and on the conditions for a blockage to occur is checked with the results of a unique experiment. We developed a test setup in which the conditions for riser blockage are enforced. We were able to conduct a reproducable blockage experiment, which shows that the mechanism presented in this paper is a very accurate description of the blockage process.
To ensure safe operations and high production levels, the transport system needs to be designed for maximum flow assurance. Knowledge of the mechanism and conditions for riser blockage can be used in the design of feeding systems and strategies for the vertical transport system.

• 出版日期2015-6-1