Investments and projects developed in the Oil and Gas (O & G) industry involve complex equipment, infrastructure, and processes. Additionally, Research and Development (R & D) activities play an important role in competitive potential and productivity growth in which scenarios may involve more than one option of projects to be accomplished. A solid and reliable background for decision-making is fundamental to the strategic level using well-structured methods to support their selection or classification as many criteria must be taken into consideration. Since precise data is scarce, it is necessary to understand how to measure the criteria. This paper develops a systematic literature review to investigate the methodologies currently used for selecting and/or ranking projects, especially regarding new technologies that can significantly support companies' decisionmaking processes in the O & G sector. The main paper contributions include mapping selection/ranking methods, application areas, already applied criteria, and a research agenda. We searched for articles on this topic in the specific area of O & G, and then we expanded to general areas, resulting in 29 articles in total. The bibliometric data shows Engineering and Management as the most prominent areas in this subject. When focusing on O & G, we highlight the applied methodologies for decision-making in ranking technologies, such as mathematical programming, artificial intelligence, and decision theory. In addition, we report the main criteria employed to evaluate the projects and gaps concerning the selection of new technologies, such as the absence of equipment reliability as a factor. As the number of studies in the O & G field is small, applications mainly in the R & D domain are encouraged. In this sense, the research agenda suggests a wide range of possibilities when combining methods and exploring criteria such as risk and reliability.