This comprehensive review explores the multifaceted role of kerogen in organic-rich mudrock reservoirs, focusing on its impact on porosity, hydrocarbon storage, and transport pathways. The dominance of kerogen-hosted pores is underscored as a critical determinant of reservoir dynamics, with an emphasis on the wettability of kerogen as a pivotal parameter. The intricate relationship between kerogen wettability and petrophysical properties, including water saturation and electromagnetic characteristics, is elucidated, emphasizing the broader implications for reservoir management and hydrocarbon recovery.
The study delves into the thermal maturation of kerogen, unraveling the chemical evolution from hydrogen-rich organic matter to hydrogen-poor residual carbon. The Van Krevelen diagram visually depicts the transformation, highlighting the decreasing oxygen-to-carbon ratio with increasing thermal maturity. Distinct types of kerogen are examined, each exhibiting variable compositions, providing a nuanced understanding of their behavior under different thermal maturation levels.
Temperature emerges as a crucial factor influencing kerogen wettability, drawing parallels with observed shifts in conventional reservoirs during thermal recovery processes. The impact of temperature on kerogen-oil interaction within shale pores is explored, revealing noteworthy variations in the density distribution of adsorbed oil molecules. Linear relationships between temperature and confined oil compounds further emphasize the need to comprehend the interplay between temperature and kerogen wettability for effective thermal recovery mechanisms.
The review concludes by highlighting the necessity of advancing molecular dynamics simulations to capture the complexity of kerogen molecular structures, diverse kerogen types, and temperature variations. By addressing these challenges, future simulations can contribute to a comprehensive understanding of kerogen wettability, offering valuable insights for hydrocarbon reservoir characterization and optimization of recovery strategies.