Integrated Geological, Geophysical and ‘Reservoir’ Modeling and Simulation of the Jackfork Group at the Baumgartner Quarry Area, Western Arkansas: Implications to Gulf of Mexico Deepwater Exploration and Production

The Early Pennsylvanian deepwater Jackfork Group in Arkansas has been the subject of studies, field trips and publications for many years because of excellent outcrop exposures of different deepwater architecture elements. This latest study is focused within Baumgartner Quarry, near Kirby, Arkansas, which exposes a series of vertical walls in 3-dimensions. This quarry has not been as well documented as other popular exposures, even though 3D quarry faces exist, and the quarry strata comprise part of a complete, 600m thick, near-continuous, Jackfork stratigraphic sequence not unlike younger, deepwater stratigrapihc exploration targets in the deepwater Gulf of Mexico and elsewhere. Subsurface problems such as solving sub-seismic reservoir uncertainties, reservoir performance of lobe vs. channel deposits are addressed based on our work of in the quarry.

A 3D sequence stratigraphic model was developed mainly on the basis of numerous measured stratigraphic sections in the quarry. The 180m thick quarry strata consist of a lower Lowstand Systems Tract (LST) “Lower Sand”) dominated by channel-fill sandstones, overlain by a shaley Transgressive Systems Tract (TST) (Condensed Section), and then by an upper Lowstand Systems Tract (LST) (“Upper Sand”), dominated by sheet or lobe sandstones. This stratigraphy indicates the younger lowstand sedimentation cycle did not extend as far basinward as the lower cycle at this position within the basin. This model was translated into a 3-way updip-against-salt field which is analogous to some deepwater Gulf of Mexico reservoirs. Performance simulation was conducted on the model using one injector well and two vertical producing wells, one of which was connected to the injector via a channel sandstone and the other of which was offset from the channel sandstone. Results yielded 60% more production from the connected injector-producer pair than from the non-connected pair. Comparison between the Lower (channel-prone) Sand LST and the Upper (lobe-prone) Sand LST revealed that the lobe-prone LST is more sustainable over a ten-year production period whereas the channel-prone LST exhibits a larger drop in production rate. These results illustrate the value of 3D outcrop models for reservoir performance simulation for development planning of deepwater fields with limited data control over a large area, such as in the deepwater Gulf of Mexico.

AAPG Search and Discovery Article #90142 © 2012 AAPG Annual Convention and Exhibition, April 22-25, 2012, Long Beach, California