This paper aims to further develop the theoretical framework of energy security society, which was sketched by Aalto (2009) and developed by Aalto and Korkmaz-Temel (2012, 2014) and Korkmaz-Temel (2016). Drawing on the English School theory of International Relations and particularly Barry Buzan’s international society approach, the concept of energy security society serves as a framework to analyse different types of energy relations and different dimensions of energy issues. The concept of “three traditions”, which refer to realism, rationalism and revolutionism, of the ES theory and Buzan’s interpretation of this concept by including these three traditions as integration types allow us to examine energy relations based on not only conflict but also convergence. Furthermore, the concept of primary institutions provides us a broad coverage of different understandings of energy issues. The paper applies this framework to EU’s energy policy in the sphere of natural gas. Utilising Buzan’s criteria for a “great power”, the paper scrutinises the energy reserves, infrastructure, technology, questions the extent of which the Energy Union can be considered as “self-declared status” and examines the attitude of third parties. Overall, the paper analyses what kind of integration the EU seeks for in the sphere of natural gas and potentials and limitations of internal and external integration in this field by using the theoretical framework of energy security society.