An Integrated Geological and Petrophysical Study of a Shale Gas Play: Woodford Shale, Permian Basin, West Texas

We present an integrated stratigraphic, sedimentological, geochemical and petrophysical study logs from the Upper Devonian Woodford Shale Permian Basin, west Texas. Our work, based on long cores and well logs, demonstrates variations in shale lithofacies, mineralogy and rock composition at multiple scales that are associated with 2nd, 3rd and possibly 4th order sea level cycles. The 3rd order cycles are evident in bundles of ‘exotic beds’, repeated at a scale of approximately 10 meters. Carbonate or siliciclastic sediments derived from the basin margins and transported distances of several tens of kilometers to the middle of the basin. The composition of these beds depends on the composition of the nearest source terrane; adjacent to carbonate platforms, the beds consist of carbonate turbidite and debris flow beds, while elsewhere they form thin siliciclastic turbidite beds.