Abstract

Pore attributes and microstructural features critically govern the storage capacity and hydrocarbon migration potential of shale reservoirs, which are strongly dependent on the geometry distribution and connectivity of the pore system. However, the highly heterogeneous and anisotropic nature of shale pore networks make their characterization challenging. Understanding these properties for unconventional reservoirs like shale, this study involves utilization of high-resolution Scanning Electron Microscopy (SEM) imaging technique which provide an unprecedented view of the shale matrix, sheds light on the intricate details of storage, fluid transport and reservoir behavior. These SEM images along with advanced image processing and segmentation techniques were applied to quantify the detailed pore-scale attributes and pore connectivity of shale rock from Indian Gondwana formation of the South Karanpura coalfield. The results reveal a strong correlation in depth-dependent variation in shale pore systems with experimental data, both quantitatively and qualitatively. Sample of shallow depth interval show high porosity, pore size, throat distribution and better connectivity, in comparison to the higher depth interval sample indicating restricted fluid mobility despite retaining some storage capacity. The findings highlight storage and transport potential of unconventional reservoirs and address; how burial depth alters pore attributes and connectivity. This study demonstrates the effectiveness of SEM-based digital rock analysis for resolving shale characteristics by providing valuable insights for predicting reservoir quality and optimizing recovery for sustainable development of unconventional shale reservoirs