Science – Society – Technology
Flow rate, L/s | Flow velocity, m/s | Pressure, bar | Process | |
---|---|---|---|---|
Start of production | 110 | 1.40 | 12 | Remobilization of existing scale particles due to turbulence. Pump rate is increased too fast to allow for ripple formation and stabilization |
Full production (scenarios 1 and 2) | 110 | 1.40 | 12 | Slow scale precipitation due to degassing and oversaturation. Velocity > calculated ripple washout velocity, therefore no ripples predicted |
Shut-down of production | 0.1 - 0.5 | 0.00 | 1 - 4 | Solid particle deposition (ripples) of suspended particles followed by stabilization of scales due to sudden pressure drop and degassing. Too little particle supply |
Acid treatment (scenarios 3 and 4) | 5 | 0.06 | 1.8 - 2.6 | Acid causes remobilization of partially dissolved scale particles and subsequent solid particle deposition (ripples). Oil prevents total dissolution of scales. Stabilization of ripples takes place when pH rises too high |
Flushing of facilities with tap water after acid treatment (scenarios 3 and 4) | 6.5 | 0.08 | 1.6 - 3.5 | Stabilization of ripples by calcite precipitation due to high calcium ion concentration in the cleaning solution and a neutral pH of the tap water |