TRACKING THE FOOTPRINT OF DRILLING MUD BY IDENTIFYING BARITE IN SEDIMENTS USING X-RAY DIFFRACTION

Barite (BaSO4) is a common agent added to drilling muds in order to increase their density and reduce the risk of explosion during the drilling process. The general focus of this study is to determine whether barite present from drilling mud can be identified in sediment cores collected throughout the northern Gulf of Mexico (NGoM) using X-Ray Diffraction (XRD) methods. The cores analyzed for this project were chosen based on proximity to drilling sites and primarily near the location of the Deepwater Horizon (DWH) rig. Sediment samples were taken from cores at (2 cm intervals) and chosen based on data acquired by X-Ray Fluorescence scans (0.5-1 cm intervals), showing quantitatively where elemental barium was concentrated downcore. Sediment samples were freeze-dried, finely ground to pass through a 45 µm sieve, and homogenized to obtain the most ideal representation of crystalline phases. Mineralogical analyses were performed using a Rigaku miniflex 6G X-ray diffractometer along with the Crystallography Open Database (COD) for phase matching and Rietveld refinement for quantification. The expected result is to identify mineral barite in relation to the maxima in the elemental barium from initial XRF data. This will aid further evaluations of the implications of barium in benthic environments associated with ongoing drilling activity and potentially provide a more persistent tracer for past and future oil spill events. Additionally, we aim to determine the extent of spatial distribution of the DwH event and its preservation in the sedimentary record by using barite as a proxy.