ABSTRACT

Consolidation laminae and dish structures form high-density zones that are interpreted to have formed by disruption of primary structures during gravitational collapse of the grain framework during water escape and consolidation. They are not associated with higher contents of clay-size material than adjacent units, but the chloritic clay minerals associated with consolidation laminae and dish structures have a different microtexture than observed elsewhere. Clay mineral texture has a direct effect on petrophysical characteristics, in particular water saturation and conductivity in hydrocarbon-saturated intervals. CT-scans identify consolidation laminae and dish structures as zones of high density that correspond to tighter packing of sand grains and are unrelated to clay distribution. Dish structures may form independently of consolidation laminae or by further modification of fragmented consolidation laminae.