Hydration-induced damage of tight conglomerates

Abstract

This study endeavors to delve into the microscopic mechanisms of hydration-induced damage in tight conglomerates. Initially, we obtained data on the micro-morphology, elemental composition, and mineral composition of the conglomerate using field emission scanning electron microscopy imaging, EDS energy spectrum analysis, X-ray diffraction mineral experiments, and image fine processing techniques. Subsequently, a conductivity meter was employed to gauge solution conductivity throughout the process, while a high-resolution camera monitored changes in appearance morphology. The hydration samples were then re-examined using field emission scanning electron microscopy imaging and EDS energy spectrum experiments. Our analysis reveals that the extent of hydration-induced damage in the conglomerate samples correlates with their pore and fracture parameter characteristics, as well as their elemental and mineral composition. Notably, samples with higher surface porosity and tortuosity are more susceptible to hydration-induced damage, whereas those with higher circularity, solidity, and degree of orientation of the angle exhibit lower susceptibility. The circumference and aspect ratio display weak positive and negative correlations with the degree of hydration-induced damage in the conglomerate, respectively. However, the detailed mechanism warrants further investigation. Furthermore, samples with elevated montmorillonite content are more prone to hydration-induced damage, whereas those with increased Fe and illite content are less likely to suffer from hydration-induced damage. These findings offer novel insights into the microscopic mechanisms underlying dynamic hydration-induced damage in conglomerate samples and hold significant implications for guiding the efficient development of conglomerate oilfields.