A novel fluid dynamic based approach for optimized gas lift operation

Abstract

Gas lift has been successfully operated in many types of oil wells around the world. Many techniques have been derived to increase gas lift efficiency, not only from gas lift modeling but also technical designs of gas lift components have been tweaked to produce higher gas lift performance with less gas injected.Gas Lift Performance Curve currently holds as one of the most prominent evaluation method of gas lift performance. The method itself is derived as a subcomponent of Inflow Performance Relationship (IPR) curves that allows simple and robust GLP curve generation without having to perform procedural, iterative calculations. It is worth noting, however, that GLP curves cannot be held as a single culmination parameter in determining the efficiency of gas lift systems. This study introduces a new paradigm in modeling the performance of gas lifted wells by utilization of mechanistic fluid flow modeling. Mechanistic models, unlike conventional GLP curves, are generated from observations in full scale laboratory experiments, therefore complications in multiphase flow pattern, such as flow pattern transition can be fully acknowledged and incorporated into the calculations. Based on the previously stated hypothesis, this study offers a case study on marginal oil well where gas lift acts as the main extraction method. Observations done in the model has confirmed the functionality of Flow Pattern Map (FPM) derived from mechanistic modeling as a complementary check and balance tool for gas lift systems. It is also expected that the FPM will perform well in a multitude of gas lift case studies due to its versatility.