Jurassic, Cretaceous, and Tertiary sediments in the East Texas Basin have been structurally modified by movement of Middle Jurassic Louann Salt.

Regional surface and subsurface studies indicate that thick deltaic (Queen City Formation) and thin shelf (Reklaw and Weches Formations) sequences compose the stratigraphic interval between the top of the Carrizo Sand and the base of the Sparta Formation.

Analysis during the second year was highlighted by a historical characterization of East Texas Basin infilling, the development of a model to explain the growth history of the domes, the continued studies of the Quaternary in East Texas, and a better understanding of the near-dome and regional hy

The Leonardian Spraberry Formation is a major oil-producing formation of the Permian Basin, accounting for more than 700 million barrels of oil produced from heterogeneous submarine-fan reservoirs.

More than 350 well logs and core and production data were used to geologically characterize oil reservoirs of the Driver waterflood unit of the Spraberry Trend in the Midland Basin, West Texas, and to assess the relationship between reservoir stratigraphy and oil recovery.

Unrecovered mobile oil is oil that is movable at reservoir conditions but is prevented from migrating to existing we1 l bores because of geologic complexities or heterogeneities.