Oil and gas exploration in tight reservoirs of fine-grained sedimentary systems has received increasing attention due to the rising global demand for oil and gas and the ongoing progress in exploitation technologies. Compared to conventional reservoirs, fine-grained reservoirs are characterized by low pore-throat radii, making it difficult for the formation fluid to flow through. Therefore, accurate evaluation of the oil and gas properties of tight reservoirs in fine-grained sedimentary systems is essential for estimating and modeling the potential, recoverability, and productivity of tight resources.

However, the factors influencing oil and gas accumulation in fine-grained sedimentary systems are multifaceted. From previous research, physical characteristics, organic geochemical indicators, sedimentary environment, geofluids, and tectonic activities can indicate oil and gas accumulation in fine-grained sedimentary systems. Moreover, in recent years, new physical experimental methods and advanced numerical simulation methods have enabled researchers to gain a deeper understanding of fine-grained sedimentary systems and their hydrocarbon accumulations.

The Special Issue aims to present recent progress in understanding the mechanisms behind oil and gas accumulation in fine-grained rocks, including shale, mudstone, and tight sandstone. We hope to present critical reviews of previous work and new approaches and recent research studies analyzing the processes of hydrocarbon generation and accumulation in fine-grained rocks. Shale gas reservoir characteristics and hydrocarbon-bearing fluid activity in shale are of particular interest. Contributions on the geochemical and sedimentary characteristics of fine-grained sediments are also sought. We welcome both original research and review articles.

Potential topics include but are not limited to the following:

• Characteristics of fine-grained reservoirs
• Oil and gas accumulation mechanisms in fine-grained sedimentary systems
• Overpressure origin and fluid activity in organic-rich shale
• Fluid-rock interaction and organic-inorganic interactions during diagenesis in shale
• Sedimentary and geochemical characteristics of fine-grained sedimentary systems