Primary recovery efficiency is low in Delaware Mountain Group reservoirs because of serious production problems, particularly low reservoir energy and high water production. Unless methodologies and technologies to overcome these production problems are applied, much of the remaining oil in Delaware sandstone fields will not be recovered. Our objective in conducting reservoir-characterization studies of the Ford Geraldine and East Ford units was to provide insights that are applicable to all slope and basin clastic fields in the Delaware Basin. The technologies used for reservoir characterization included subsurface log, core-analysis, and petrophysical study. Petrophysical analysis was complicated by the incomplete nature of the logging suites in both units. In the Ford Geraldine unit, 118 wells have no porosity logs, and of the remaining 187 wells, 84 of them have only old neutron logs. Only 38 wells have both porosity and resistivity logs. In the East Ford unit, only 26 of the 45 wells have porosity logs, and only 17 wells have both porosity and resistivity logs. The old gamma-ray and neutron logs were run by many different companies at different scales and sensitivities. Because of these problems, not all of the methods of a modern petrophysical analysis (Asquith and Gibson, 1982) could be used. Thus, the objective of the petrophysical characterization of the Ford Geraldine and East Ford units was to develop a method of log interpretation that would combine traditional techniques with some new methods and allow quantitative petrophysics to be accomplished with the old logs.