High-Resolution Reservoir Characterization of Midcontinent Sandstones Using Wireline Resistivity Imaging, Boonsville (Bend Conglomerate) Gas Field, Fort Worth Basin, Texas

David L. Carr, Robert Y. Elphlck, and Laura Stager Foulk

In the absence of abundant core data, Formation MicroScanner (FOOTNOTE *) (FMS) and Fullbore Formation Microlmager (FOOTNOTE *) (FMI) wireline logs from 3 wells in Boonsville Field provided continuous geologic information in a 1000-foot thick, Pennsylvanian (Atoka) interval. Cores provided the most detailed sequence-stratigraphic information, but only 358 ft of core from 4 wells was available to evaluate the 30 mi² project area. The FMS and FMI logs thus served as continuous, oriented 'virtual cores' that expanded our stratigraphic database and improved our interpretations, which included the identification of key chronostratigraphic surfaces, lithofacies, sedimentary structures, faults, and fractures.

Paleocurrents inferred from the FMS and FMI images suggest that most Bend Conglomerate sandstones are lowstand valley-fill deposits derived from the Muenster and Red River Uplifts, rather than Ouachita-derived deltas. Combined analysis of cores and wireline resistivity imaging technology enabled the development of a fine-scale, sequence-stratigraphic framework which formed the basis for correlation and mapping of the major Bend Conglomerate reservoir zones, and helped us to identify compartmentalization mechanisms within these complex reservoirs.

FOOTNOTE *. Mark of Schlumberger

AAPG Search and Discover Article #91019©1996 AAPG Convention and Exhibition 19-22 May 1996, San Diego, California