1. Gas-Lift Surveillance Techniques
Jim Hall, Shell International EP
Cleon Dunham, Oilfield Automation
20 – 30 Participants

2. 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?

3. 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

4. Gas-Lift Surveillance
Performance Indicators
TGLR Hydraulic effectiveness
IGLR Economic effectiveness
FGLR Must be calculated
BS&W 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

5. 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
Production pressure
Manual Fairly common
Automatic Very specialized
1 If using downhole control, need automatic fallback to surface method