Oil exploitation and transportation are very important activities for the economic development of the industrial modern society. However, these activities are generating risks that are translated in accidental or chronic contaminations that directly affect the ecosystem. It is important that oil companies carry out a correct maintenance of their oil fields. In cases of scheduling maintenance of 200 or more oil wells, our so-called PAE, is a tool able to provide a maintenance visit schedule at the right moment. PAE uses an evolutionary algorithm to produce multiple solutions to this problem. In this work, we study the application of different types of penalty functions to a constrained scheduling in oil wells. Details of implementation, results, and benefits are presented.