Combination of electrical submersible pump and gaslift for offshore wells in Vietnam

Abstract

Artificial lifting systems have been in use for a long time all over the world. Artificial lifting systems act on the fluid column in the tubing to support and push the fluid column to the surface. Through the use of each method separately, we can analyze the advantages and disadvantages, the impacts and limitations of each method on the fluid column in the tubing, from which we can design an artificial lifting system to optimize production. In addition, practical limitations also have negative effects on the system such as injection pressure and injection gas available causing a restriction on the production when using GL, or pump horsepower and power supply causes limitations when using ESP. For those reasons, we can combine the two methods together to create an efficient production system. In this study paper, the effects on the fluid column in the tubing are analyzed when combining two methods, which are the GL method and the ESP method. Each method causes a different effect on the fluid column. That difference in this paper will be analyzed based on the "equivalent depth" method, which will represent the pressure points at each position in the tubing when using each artificial lifting method. In addition, we will use the "nodal analysis" method to find out the actual product of the production system when using a combination of the two methods. Based on the analysis of two methods "equivalent depth" and "nodal analysis", it has been proved that it is feasible and appropriate to combine the two methods GL and ESP for many special production wells that can be used for specific fields, such as deep wells. The systems of this combination can be used for wells for long time with respect to the pressure drop over time.