Estimating information about reservoir properties from seismic data is a key challenge in exploration and in the appraisal and production of hydrocarbons. We discuss how to perform quantitative reservoir characterization by integrating well-log and seismic-inversion data through the application of the multiattribute rotation scheme (MARS). This method is a hybrid rock-physics/statistical approach that uses a global search algorithm to estimate a customized transform for each geologic setting in order to predict petrophysical properties from elastic attributes. The transform is computed using measured and/or rock-physics-modeled well-log information and is posteriorly applied to seismically derived elastic attributes to predict the spatial distribution of petrophysical reservoir properties. This workflow was applied on the Darwin Field, located in the South Falkland Basin, which consists of two adjacent tilted fault blocks: Darwin East, which contains the discovery well 61/17-1, and Darwin West, which remains untested. The resulting rock-property volumes (water saturation, clay content, and total porosity) characterize the heterogeneity of the reservoir and were used to delineate the extension of the proven reservoir and to delineate other potential plays in the area. In addition, these property volumes can be used as inputs for static model generation and reserve estimation, as well as to optimize the exploration and exploitation plan for the area.