The Industry Challenge
Several Steam Assisted Gravity Drainage (SAGD) operators have observed flow instabilities in their Electrical Submersible Pump (ESP) produced wells, commonly resulting in the complete loss of fluid flow to surface. In some wells these instabilities appear without any apparent precursor signs or indications of a potential flow disturbance, while in other wells there are clear indications of gas entering the pump (e.g. evident by flow and current fluctuations).
In many cases the wells are unable to resolve the “no-flow” condition and must be shut-in or operated at a reduced speed to regain any flow to surface. Left unchecked this issue ultimately prevents SAGD Operators from drawing down their production wells to their full potential.
How the JIP Helps
In early 2017, a group of five SAGD operators launched a JIP at C-FER to further assess the mechanism(s) causing these inflow instabilities and no-flow events.
The Phase of this work is focused on investigating the two-phase flow patterns that may exist in horizontal wells, upstream of the ESP and leading up to the ESP intake, using a combination of 1D models and Computational Fluid Dynamic (CFD) simulations to evaluate the amount of gas (water vapour or non-condensables) and liquid that approach the first ESP stages, and then to evaluate the influence of this gas on the two-phase performance of the ESP’s.
Ultimately this applied research will likely focus on guiding the operators towards future mitigating actions, such as applying different operational strategies, deploying different ESP equipment, or different completion schemes to help them improve production.