Intisar A oil field is a Libyan field located in Concession 103 and has been in production since 1968. In this paper, we report the field evaluation results of the various productions enhancement techniques and initiatives applied for incremental oil production. The impact of improved recovery by various waterflood optimisation processes including infill well drilling, installations of ESPs, current well re-completion, and conversion wells were evaluated taking into consideration surface facility constraints. An incremental total daily production of 9872 STB/D was achieved in the overall optimisation projects with infill horizontal well drilling producing the highest incremental recovery. The internal rate of return for the overall project was 72% and a payback period of 3.4 years. The lessons learned, and recommendations for future development of the field were established.