The Sirt Company is one of large Libyan companies that use the gas lift method in Zelten Field, Libya, but they have a problem with it, where they consume a large volume of lifting gas (up to 1 MMscf/d for well) to obtain a high oil rate which is the main goal for production engineers. In addition, lifting gas results in high water rate based on the idea of increasing injection gas lead to high liquid rate.

This study will consider reservoir engineers’ viewpoint in addition to production engineers’ viewpoint to solve this problem, as a study of reservoir management.

The idea of this study relies on trying several scenarios of wellbore conditions to choose the best one that maintains oil production rate with less water production rate and injected gas. The study will use samples (from wells C–82 and C–117) and petroleum software (Prosper and tNavigtor). The methodology of the study consists of several steps where first we build a model for two wells by Prosper using real data, then link the results of Prosper to a sector model of Zelten Field and run this model using tNavigtor simulator, finally comparing among scenarios for qualitative analysis and selecting best one that achieves the ideas of reservoir and production engineers.