Gas-Lift Surveillance Techniques

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Gas-Lift Surveillance Techniques Jim Hall, Shell
International EP Cleon Dunham, Oilfield
Automation 20 30 Participants
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• Gas-Lift Surveillance Techniques
• Objectives
• Deep
• Stable
• Optimum
• Data gathering / reporting
• Charge 95 of data not used
• Objective
• Collect key data once per minute
• Have system check all data
• If well is OK, nothing is reported
• If well is sick (exception), it calls for help
• People use data to troubleshoot problem wells
• What data is needed?

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• Gas-Lift Surveillance
• Measurements Need Want Use
• Surface
• Pinj Y Y GL analysis
• Qinj Y Y GL analysis/control
• Pwh Y Y GL analysis
• Qliq Y GL optimization
• Twh Y Detect change in H2O
• Pfl Y GL analysis
• Tambient Y Twh analysis
• Downhole
• Pwf Y GL optimization
• T Y GL analysis
• Qinj Y GL analysis/control
• Qsinglephase Y GL optimization
• Tcontinuous Y GL troubleshooting

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• Gas-Lift Surveillance
• Performance Indicators
• TGLR Hydraulic effectiveness
• IGLR Economic effectiveness
• FGLR Must be calculated
• BSW What is being lifted
• Others
• What if Downhole Instruments Fail
• Run flowing gradient survey
• Conduct accurate well test
• Calibrate multi-phase model
• Use calibrated model with measured surface data
  in between surveys and well tests

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• Gas-Lift Control Method
• Control Method Frequency of Use
• Lift gas rate
• Manual Common
• Automatic Fairly common
• Downhole1 Very new
• Injection pressure
• Manual -
• Automatic Rarely
• Downhole1 Very new
• Production pressure
• Manual Fairly common
• Automatic Very specialized
• 1 If using downhole control, need automatic
  fallback to surface method