Mineral replacement in long-term flooded porous carbonate rocks

摘要

This study reports mineralogical and physical property changes linked to geo-chemical alterations processes during three ultra-long-term tri-axial tests on outcrop-chalk from Liege (Belgium). The test core plugs were flooded with MgCl2 -brines for approximately one and a half, two and three years, mimicking effective reservoir stresses (9.5-12.5 MPa) and temperature (130 degrees C) of important hydrocarbon deposits at the Norwegian Continental Shelf. The flooded cores were studied using electron microscopy, whole-rock and stable isotope geochemical analyses, and ion chromatography of the effluent water.