Glenn Pool oil field, discovered in 1905, is considered a mature field, and yet contains substantial amounts of potentially remaining recoverable reserves. Glenn Pool is a giant oil field that has produced over 330 MMbbl (million barrels) oil from the Pennsylvanian Bartlesville (Glenn) sandstone using primary and secondary methods, with limited tertiary recovery efforts. Despite a long history of production, some production tracts have recovered a total of only 21% of original oil in place, with many wells currently exhibiting water cuts of 99% or higher. Results reported here are part of a reservoir characterization and management effort aimed at improving recovery in Glenn Pool field. This effort involves an industry-academic-government partnership included within the U.S. Department of Energy's Class I (fluvial-deltaic reservoir) initiative. Focus of the Glenn Pool Project has been on the Self unit, a 160 ac (64 ha) tract in the southeastern portion of the field. A combination of detailed geologic study, geostatistical modeling, and reservoir simulation has been employed to design and implement improved recovery strategies. A crucial result of this work has been a reinterpretation of Bartlesville depositional systems and facies architecture in northeastern Oklahoma. With only one-quarter of the total implementation plan in effect, oil production more than doubled, exceeding expectations. Water production, however, remains high. Additional management plans are under consideration.