Fate of Drilling Fluids during the South McMurdo Sound Project (SMS) of the Antarctic Geological Drilling Program (ANDRILL)

知识优势：PI建议利用水文地质学家使用的计算机模型来确定污染的命运和运输，并确定ANDRILL SMS岩心中钻井液污染的程度。对于这些模型，将之前收集的岩性、孔隙度、裂缝密度、裂缝类型、裂缝方向、钻井液漏失、钻井液特性和温度等测井数据作为输入参数。此外，将确定钻井液的生物降解和吸附常数，并将其纳入模型。取心过程中使用的钻井液样本以及回液样本在钻井现场使用标准微生物取样技术收集。流体将在原位温度下在好氧和厌氧条件下进行测试，以确定生物降解常数。将使用标准等温线方法测定钻井液和岩心样品之间的吸附。流体的地球化学和微生物指纹图谱以及生物降解过程中的变化将确定钻井液对南极洲南麦克默多海湾下各个地下岩性单元内孤立的微生物群落和地球化学的潜在影响。如果这项研究认为有必要的话，这项研究的结果可能会为未来开发危害较小的勘探方法提供指导。更广泛的影响：这个拟议的项目将培养一名研究生。为本项目样品分析所开发的方法将作为今后类似研究的指南，并将增进对南极洲地质钻探的生态影响的了解。本研究的结果将作为参考，与未来在原始环境中勘探钻井项目中研究新开发和改进的样品收集方法的研究进行比较。南极考察队是南极研究的新手。

Intellectual Merit: The PI proposes to utilize computer models used by hydrogeologists to establish the fate and transport of contamination and determine the extent of drilling fluid contamination in the ANDRILL SMS core. For these models, previously collected logs of lithology, porosity, fracture density, fracture type, fracture orientation, drilling fluid loss, drilling fluid characteristics and temperature will be used as input parameters. In addition, biodegradation and sorption constants for the drilling fluid will be determined and incorporated into the models. Samples of drilling fluids used during coring as well as the return fluids were collected at the drill site using standard microbiological sampling techniques. Fluids will be tested at in situ temperatures under aerobic and anaerobic conditions to determine biodegradation constants. Sorption will be determined between the drilling fluids and core samples using standard isotherm methods. Geochemical and microbial fingerprints of the fluids and the changes during biodegradation will determine the potential impact of the drilling fluids on the isolated microbial communities and the geochemistry within various subsurface lithologic units beneath the southern McMurdo Sound in Antarctica. The results of this study could potentially provide guidelines on developing less detrimental methods for future exploration, if deemed necessary through this research.Broader impacts: This proposed project will train a graduate student. The methods developed for analyses of samples in this project will serve as a guide for future studies of similar interest and will improve the understanding of ecological impacts of geologic drilling in Antarctica. The results of this study will be used as a reference for comparison with future studies examining newly developed, and improved, sample collection methods in future exploratory drilling projects in pristine environments. The PI is new to Antarctic research.