A deep subsurface rock core for paleoclimate reconstruction was collected in October and November 2007 during the South McMurdo Sound Project (SMS) of the Antarctic Geological Drilling Program (ANDRILL). To allow for deeper penetration and more efficient core recovery, water-based saline drilling fluids were utilized. A total of 5. 6×105 L of fluids was lost in the subsurface. The fluid was comprised of surface seawater from the sound, as the wetting agent mixed with densifying compounds (mainly potassium chloride and small amounts of fourteen other compounds including biodegradable organics).
When exploring beautiful locations a main goal needs to be minimizing the quantity of natural and chemical contaminants. Introducing a poison such as going fluids could adversely alter the in situ conditions; impacting the environment even following the exploring party has departed the system. The destiny of contamination on the subsurface environment from invasive pursuit methods into beautiful environments is not well known.
In this study, computer models (MODFLOW, SEAWAT) that are widely-used by hydrogeologists to determine the destiny and transport of contamination were used to determine the extent of the drilling fluid contaminants from the ocean floor to 1100 mbsf. In these models, previously collected records for lithology, porosity, fracture density, drilling fluid loss, drilling fluid characteristics, and temperature were used as different parameters in the model.
In addition, biodegradation and sorption constants for the drilling fluid were determined. These factors are important to determine the extent and half-life of the drilling fluids in the subsurface. Samples of drilling fluids used during coring and return fluids were collected from the drill site and were used to determine the biodegradation of the drilling fluids. The overall goal of this research project is to utilize the rich data set provided,