Tight Gas Reservoirs; Opportunities, Characteristics and Challenges

The undeniable growing gap between demand and supply, and the advent of technology are making the incentive for development of the unconventional gas resources around the world. One of these unconventional gas resources that recently have attracted the attention of the researchers is the low permeability gas reservoirs, known as tight gas reservoirs. Noting that these reserves are available in enormous quantities all across the world, every and each of them are a project topic by itself and the fact that they retain some specific characteristics and reservoir complexities that are not common in other conventional gas reservoirs necessitate a comprehensive study and analysis of tight gas reservoir characteristics and their well performance. A successful exploitation of these reservoirs requires a basic understanding of the rock original pore structure and properties as well as the processes (like diagenesis) that modify those properties. In this paper, after a brevity about the world wide importance of tight gas reservoirs, a brief explanation of the basic tight gas properties and diagenetic processes affecting porosity and permeability are presented. Moreover some of the problems associated with production from such reservoirs are addressed.