The main producing formations offshore are the limestones of Cretaceous age along with discovered gas in the dolomites and sandstones of Permian to Devonian age. The oil is trapped in giant dome shaped salt cored anticlinal structures. The Formation currently being exploited as an unconventional play is the most prolific source rock for most of the oil in the Upper Cretaceous reservoirs.

The stratigraphy onshore is dominated by carbonate sequences deposited in a stack of four sedimentary basins more that formed in response to overthrusting. The basin stack is covered by late Miocene clastics and floored by middle and early Cretaceous shelf carbonates and clastics. The eastern part acreage marks the western limit of the late cretaceous to Tertiary thrust belt forming the Mountains. The thrust belt is characterized by steep dips and complex folding and faulting. Gas and condensate have been trapped in thrust anticline structures . The deepest well onshore reached over 16,000 feet.