Clay mineral diagenesis and oil migration in the Middle Jurassic Brent Sand Formation

摘要: Authigenic clay minerals, in an almost complete sequence of oil-saturated Brent Sand from oilfield the Viking Graben northern North Sea, show a transition kaolinite upper part into illite basal reservoir; replacement textures indicate that has replaced kaolinite. After early formation, it is suggested diagenesis took place synchronously with oil migration, and progressive extension saturation down through reservoir terminated diagenetic processes. Early stages are thus 9frozen9 preserved reservoir.