The effects of oil emplacement on diagenetic processes - examples from the Fulmar Reservoir sandstones, central North Sea

Abstract

The extent of quartz overgrowths and albitization of K-feldspars is lower in oil-saturated zones compared with water-saturated zones. However, microthermo-metric studies of aqueous fluid inclusions in quartz overgrowths show similar temperature ranges for both oil- and water-saturated zones (85-125°C). This suggests that quartz overgrowth development in the oil-saturated zones continued after oil emplacement, but was retarded compared with development in the water-saturated zones. The quartz cement, therefore, must have been essentially locally derived by pressure solution. -from Authors