All jetting systems require care and attention. They will not operate indefinitely without monitoring operation and occasionally troubleshooting. Below are listed some of the most common issues that occur during operation and recommended actions.

Blockage

• Sand pan slots blocked (large or agglomerated solids)
  • Remove sand pans, shut down and clean-out
• Solids cannot be fluidized
  • Jet more often or take-out solids prior to separator (wellstream desander)

Turbulence

• Fluid mixing of oil-water interface (increased OIW)
  • Jet for shorter duration (5% solids in outlet)
• Sand pushed to interface or into oil layer
  • Use larger diameter jet nozzles and less differential pressure

Erosion

• Jets eroding vessel walls
  • Use larger diameter jet nozzles and less differential pressure

Most Common Issues

• Operator running too short (incomplete sand removal) or too long (drops interface)
• Solids consolidated in separator (not jetting frequently enough)
• Slurry constipation – no place for discharged solids to go!

Automating the jetting system will take care of most issues.

Next week I will begin the discussion and analysis of cyclonic jetting systems.

References:

1. Priestman, G.H., Tippetts, J.R., Dick, D.R., “The Design and Operation of Oil-Gas Production Separator Desanding Systems”, Trans IChemE, Vol. 74, Part A, March 1996, pp. 166-176.
2. Rawlins, C.H., “Design of a Cyclonic Solids Jetting Device and Slurry Transport System for Production Systems”, paper 166118, presented at the SPE Annual Technical Conference and Exhibition, New Orleans, LA, 30 September – 2 October, 2013. https://doi.org/10.2118/166118-MS