In this work, a gas lift-based oil production wells improvement technique is presented. This technique is based on Nodal Analysis, which is applied to well head level, where the production data are available. Thus, a production model is obtained, representing the production curve. This model allows calculating the production flow and pressure drop relation that can be found in all the components of the completion system. So, it will be possible to determine the oil or gas flow that can be produced by the well, considering the perforation and completion geometry. With this information, we can build a production optimization system in order to increase the production flow rate.