Smart well is a new technology that allows greater efficiency in pre-salt production, which is currently the largest production frontier in Brazil. Another technique used in oil projects is the conversion of production wells in injector wells when there is a decline in production. Valuing an oil project that has the option to allow conversion to injector wells in the future and decide what kind of completion adds more value is one of the objectives of the decision maker in the oil industry. This dissertation addresses the use of real option theory, by using finite differences, with the objective of analyzing whether it is advantageous to adopt smart completion compared to conventional completion based on the value added by each one in an oil project with a well conversion. As final contribution, this project proposes the application of real option model, with a limited exercise interval, to decide what completion technology an oil company may consider.