Wettability controlling effects on the fluid occurrence and flow in shale gas reservoirs: Present problems and new sights

The wettability of shale is critical for the development of shale oil and gas reservoirs. Due to its complex composition, which includes organic materials and a number of different inorganic minerals, shale’s wettability may show high heterogeneity. This could significantly affect fluid occurrence and flow processes in various kinds of pores. Organic and inorganic pores may have varying capillary pressures. The methodologies to describe the capillary forces in these two varieties of pores are still lacking, though. Additionally, due to the strong capillary pressure that may prevent liquid water from entering organic pores, the mechanisms by which water and methane accumulate in inorganic pores and organic pores may differ. Therefore, the two-phase occurrence mechanisms in the various types of pores in shale continue to be difficult problems. Furthermore, because organic and inorganic pores differ in their capillary pressure and fluid occurrence, wettability can have a significant effect on relative permeability. Thus, wettability is a significant factor that impacts the exploration and development of shale gas reservoirs. The development of shale gas reservoirs could benefit significantly from a thorough understanding of wettability heterogeneity, capillary pressure, water-methane occurrence, and relative permeability.Document Type: Current minireviewCited as: Zhang, S., Wang, T., Gao, Z., Zhang, Y. Wettability controlling effects on the fluid occurrence and flow in shale gas reservoirs: Present problems and new sights. Capillarity, 2023, 9(2): 25-31. https://doi.org/10.46690/capi.2023.11.0