Structural study of Dalan and Kangan reservoir: Focused ion beam-scanning electron and transmission electron microscopy characterizations

Abstract

Reservoirs of Dalan and Kangan have recently attracted considerable interest due to their enormous energy extraction potential. However, key technical information such as composition and pore characteristics have been unavailable. This investigation conducts a comprehensive analysis of the Dalan and Kangan shale reservoirs' properties. X-ray diffraction confirmed the presence of calcite, lime, quartz, kaolinite, hematite, titania, and alumina compounds in the specimens. Electron spin resonance analysis confirmed that the reservoirs possessed paramagnetic substances. Fourier transform infrared analysis confirmed the presence of organic matter and other carbonite compounds in the reservoirs. Thermogravimetric analysis indicates that approximately 44 % of the reservoir sample consists of carbonate species, encompassing organic materials and other chemicals. The microstructure of Dalan and Kangan reservoir was also studied using a field emission scanning electron microscope and a high-resolution transmission electron microscope, demonstrating a network of microfractures, macropores, mesopores, and micropores interconnected within the clay matrix. © 2025 The Authors