Abstract
Studies on terrestrial heat flow, particularly in oil and gas reservoir systems, have gained substantial attention. While the traditional focus was on igneous and metamorphic activities, this chapter focuses on geothermics and thermogenesis in gas reservoirs, emphasizing the fundamental concepts of heat and temperature, subsurface conditions related to heat, and responses of reservoir materials to temperature changes. Geothermics, at its core, explores the source and destiny of terrestrial heat, with “geo-” denoting the Earth and “thermos” signifying heat. It is the study of heat transport and thermal conditions in the Earth’s interior. In practical terms, geothermics extends to the assessment of geothermal resources, examining heat distribution in the Earth’s outer layers and the potential for heat extraction. Moreover, this science has evolved into an applied field, with geothermal energy being a notable application that harnesses the Earth’s heat. In this context, “thermogenesis” encompasses all physical and chemical reactions in the reservoir, including gas generation, thermal gas cracking, and mineral alteration. In essence, this chapter delves into the intricate dynamics of heat and temperature within gas reservoirs, providing valuable insights into geothermics and thermogenesis, and their significance in the energy industry.