Analysis of Injectate Location at Dupont Beaumont Works

Abstract

This chapter focuses on the Oakville sands for an analysis of injectate location at DuPont Beaumont Works. Based on borehole information and seismic data, there are two nearly parallel faults (faults A and H) in the Oakville formation in the vicinity of injection wells 1 and 2, with fault A being the closer fault. Therefore, based on the reservoir test results, fault H is considered a sealed fault. This conceptualization was used in the Sandia Waste-Isolation Flow and Transport (SWIFT) modeling performed in the chapter, resulting in a small computed pressure increase that is consistent with the observed data. The SWIFT model computed an injectate location that is consistent with the observed injectate data. A realistic injectate plume definition in a brine environment was developed using several different methods. Three different methods were used to define a realistic injectate plume, that is, mass-in-place calculations, an HBL approach adjusted for brine, and use of detection limits. The three independent approaches lead to the same conclusion that a realistic injectate plume definition in a brine environment is achieved using a 10–4 or larger contour if chemical fate is considered.