Characteristics and Influencing Factors of Multi-Scale Pore Structure Heterogeneity of Lacustrine Shale in the Gaoyou Sag, Eastern China

The success of shale oil exploration and production is highly dependent on the heterogeneous nature reservoir pore structure. Despite this, there remains limited research heterogeneity characteristics pores at different scales in lacustrine reservoirs factors that impact them. This study aims to quantitatively characterize multi-scale differences found Funing Formation Gaoyou Sag. Additionally, seeks clarify total organic carbon (TOC) lithofacies type structure heterogeneity. To achieve nitrogen adsorption, scanning electronic microscope (SEM), mercury intrusion porosimetry (MIP), other experimental means were adopted combination with fractal dimension model FHH capillary. results show predominant samples are mixed (MS) siliceous (SS), a presence calcareous (CS). micro-pores dominated by inorganic mineral fewer pores. Intragranular clay two types widely found. Small (pore diameter < 50 nm) make up 89% volume (PV) 99% specific surface area (SSA). dimensions D1, D2, D3 calculated roughness surface, structural complexity small pores, large > nm), respectively. increase resulted decrease PV, SSA, while connectivity showed slight improvement. across all followed pattern: D2 D1. more complex than greater Among three lithofacies, CS had largest indicating development network. expands space required for occurrence. However, lowest among three, which hinders production. Although PV SS slightly lower CS, its average (AVE PD) significantly advantageous, making an ideal reservoir. provides important reference evaluation better develop around world.