1st Research Conference - Gulf Coast Section SEPM

Core analysis and thin-section examination shows that the maximum amount
of porosity occurs in the muddy, bioturbated facies and is diagenetic; very little
porosity occurs in the clean sand facies, which is cemented by quartz
overgrowths. The sequence of diagenetic events appears to be (1) development
of poikilotopic calcite cement, (2) dissolution of less stable components such as
feldspar, volcanoclastics, and calcite cement, and (3) development of quartz
overgrowths. Dissolution occurred probably as fresher water entered the
sandstones during the development of the base of Austin unconformity, when
Kurten was uplifted to the south, and the "A," "B," and "C" sand units were
truncated The result is a more porous and permeable reservoir on the south
end of the field which becomes progressively less permeable northward. The
north limit of the field is defined by a combination of facies change and
permeability occlusion due to the lack of secondary porosity, making Kurten
Field a diagenetic as well as stratigraphic trap.