Structural and Sequence Stratigraphic Field Course (Hill Country, Texas)

WHO SHOULD ATTEND: Geologists, geophysicists, engineers, managers, and technicians who wish to develop a better understanding of rock formations (structure and stratigraphy) and how they relate to the everyday work in exploration, development, and production.

COURSE DESCRIPTION: This field training course focuses on upper Cretaceous carbonates exposed on the Llano uplift. These formations are productive for oil and gas in the subsurface. Subsurface accumulations are discussed on analog outcrops of the actual reservoirs where participants can directly observe how depositional and structural features interact to create hydrocarbon reservoirs.

The trip begins near San Antonio where the Glen Rose, Edwards, and Austin Chalk formations are dissected by the Balcones Fault system providing several excellent fault exposures. The course then moves towards Johnson City and the central portion of the Llano uplift. Several stops illustrate a major unconformity between the Pennsylvanian and the lower Cretaceous and discussion shifts to depositional systems and sequence stratigraphy. The field component concludes with stops near Austin looking at fracture systems and their dependence on lithology in the upper Cretaceous.

During the field trip, the instructor discusses the petroleum systems of Texas, the deposition and stratigraphy of Pennsylvanian and Cretaceous sediments, and the characterization of faults and fractures in the carbonate rocks. Participants are encouraged to think about what outcrop-scale features look like in the subsurface data such as seismic or well logs, and to think about how such information can be used to infer reservoir behavior across a wide range of scales.