The Industry Challenge:
Operators report seeing events in SAGD fields where flow instabilities exist in wells being produced with Electric Submersible Pumps (ESP).
These instabilities require well operators to reduce the pump speed or, in severe cases, temporarily shut in the well then restart the pump to achieve stable production rates. The reduced production rates and production interruptions reduce the economic performance of the well.
Stopping and restarting the pump might further reduce the total run life of the pumping system. Some evidence suggests that these instabilities are caused by steam entry into the wellbore; however, steam breakout in the pump at low intake pressures or the presence of formation gas might also contribute to this issue.
Operators want to evaluate how different ESP configurations behave under known gas and steam fractions and how different equipment design strategies and modified operating procedures could be used to improve ESP performance in SAGD applications.
How We Help:
C-FER built a custom flow loop that could introduce precisely controlled mixtures of steam, air and water into the intake of a short section of ESP.
The ESP is instrumented with a pressure transducer and thermocouple in each stage of the pump which connects to a high-speed data acquisition system to monitor rapid changes in pressure and temperature during pumping.
Different flow conditions (e.g. required pump head, steam and air fractions) and pump configurations are tested to determine the conditions where the ESP has difficulties in maintaining stable production rates.