Flowback water quality data from the Kyalla-117 and Tanumbirini-1 well sites, Northern Territory

\n## **Abstract** \nAs part of the GBA program, CSIRO has undertaken an investigation of flowback water quality at two shale gas sites in the Beetaloo Sub-basin, Northern Territory. The study was conducted between late 2019 and early 2021 at the Tanumbirini-1 and Kyalla-117 well sites in the Beetaloo Sub-basin, NT, where the organic-rich shale units within the Velkerri and Kyalla formations are the primary unconventional hydrocarbon targets. The study involved measuring the concentrations of a comprehensive range of chemicals in flowback waters at periodic intervals over a 3 month period from the commencement of flowback, which followed the completion of hydraulic fracturing. Water samples from on-site flowback water storage tanks were also taken in order to provide an indication of the composition of the accumulated wastewater prior to its treatment. The chemical analyses conducted covered over 60 trace elements (e.g. arsenic, manganese, barium, boron and zinc), seven radionuclides (e.g. isotopes of radium, thorium, and uranium) and over 160 organic chemicals (e.g. hydrocarbons and phenols). The dataset is organised into four spreadsheets. Inorganics and organics data are contained in separate spreadsheets for each well site. Quality control data (e.g. blanks, replicate measurements, reference materials) are also included. The dataset also contains a copy of the report: Apte SC, Kirby J, Williams M, King JJ, Hayward J, Johnston C, Schatz J, Jarolimek CV (2021) Assessing the potential impacts of hydraulic fracturing on water quality at well sites in the Northern Territory. CSIRO Land and Water technical report.\n\n\n## **Attribution** \nGeological and Bioregional Assessment Program\n\n\n## **History** \nThe water sampling and laboratory analytical methods used to create this dataset are described in the report “Assessing the potential impacts of hydraulic fracturing on water quality at well sites in the Northern Territory”. The report also includes a full interpretation of the data.\r\nField work including water sample collection, were conducted at Tanumbirini from late November 2019 to late March 2020 and at Kyalla from October 2020 to January 2021. All water samples were collected and processed using internationally accepted protocols. The sampling design employed involved initial intensive (daily) sampling as soon as possible after the well had been hydraulically fractured, then weekly sampling for the first month, followed by monthly sampling until flowback or well operations ceased (between 3 and 4 months). Additional samples were also taken from the flowback retention ponds at both well sites. These samples gave an indication of the water quality of the combined flowback waters prior to their treatment/disposal.\r\nThis list of chemicals to be analysed was developed following a review of relevant published literature on shale gas operations. Wherever possible, sample analyses were conducted in NATA (National Association of Testing Authorities, Australia) accredited laboratories which includes the CSIRO laboratory at Lucas Heights. The quality control (QA/QC) program adopted in the study included field duplicates, laboratory replicates, blanks, spike recovery tests and where available, analysis of certified reference materials. Analysis for organic target compounds was conducted by the National Measurement Institute, Sydney (NMI) which is NATA accredited facility. All radiochemical analyses were conducted by the Australian Nuclear Science and Technology Organisation (ANSTO). Biocide analysis was conducted at the CSIRO Land and Water laboratory in Adelaide.

## **摘要**
作为GBA计划的一部分，CSIRO对北领地比塔罗亚次盆地的两处页岩气井场开展了返排水质调查研究。本次研究于2019年末至2021年初在北领地比塔罗亚次盆地的塔努姆比里尼-1（Tanumbirini-1）与基亚拉-117（Kyalla-117）井场进行，该区域内韦尔克里（Velkerri）组与基亚拉（Kyalla）组的富有机质页岩层系为主要非常规油气勘探目标。
研究在水力压裂作业完成后的返排阶段，于返排启动后的3个月周期内定期采集水样，测定了多类化学物质的浓度。同时还采集了井场返排废水储罐中的水样，以表征处理前累积废水的组分特征。本次化学分析涵盖60余种微量元素（如砷、锰、钡、硼与锌）、7种放射性核素（如镭、钍、铀的同位素）以及160余种有机化合物（如烃类与酚类物质）。
本数据集分为4个电子表格，各井场的无机物与有机物数据分别存储于独立的电子表格中，同时包含质控数据（如空白样、平行样、标准参考物质测定结果）。此外，数据集还附带了以下报告的副本：Apte SC、Kirby J、Williams M、King JJ、Hayward J、Johnston C、Schatz J、Jarolimek CV（2021）《评估北领地井场水力压裂作业对水质的潜在影响》，CSIRO土地与水技术报告。

## **归属**
地质与生物区域评估计划

## **研究历史**
本数据集所采用的水样采集与实验室分析方法均载于报告《评估北领地井场水力压裂作业对水质的潜在影响》，该报告同时包含了对数据集的完整解读。
野外作业（包括水样采集）于2019年11月下旬至2020年3月下旬在塔努姆比里尼井场开展，2020年10月至2021年1月在基亚拉井场开展。所有水样均按照国际公认规程进行采集与处理。
本次采样设计遵循以下方案：在井场完成水力压裂后立即启动密集的每日采样，首月转为每周采样，随后改为每月采样，直至返排作业或井场作业终止（时长约3至4个月）。此外，还在两处井场的返排废水滞留池采集了额外水样，以表征处理/处置前混合返排废水的水质特征。
本次分析的目标化学品清单是在梳理有关页岩气作业的已发表相关文献后制定的。在可行情况下，所有样品分析均在澳大利亚国家检测机构协会（National Association of Testing Authorities, Australia，NATA）认可的实验室进行，其中包括位于卢卡斯高地的CSIRO实验室。本研究采用的质量控制（QA/QC）方案涵盖野外平行样、实验室平行样、空白样、加标回收试验，以及有条件情况下的标准参考物质分析。有机目标化合物的分析由位于悉尼的澳大利亚国家计量院（National Measurement Institute, Sydney，NMI）完成；所有放射化学分析均由澳大利亚核科学与技术组织（Australian Nuclear Science and Technology Organisation，ANSTO）开展；杀生剂分析则在阿德莱德的CSIRO土地与水实验室进行。