Re-examination of aquitard intergrity using new methods

在全球和许多区域，含水层污染是一个日益严重的问题。污染的程度和时间取决于含水层上覆的弱透水层（低渗透层）的特性。 弱透水层完整性是指弱透水层保护下层弱透水层免受污染的能力。这项研究有两个目标：第一个是开发一种新的方法，通过在每个研究地点从单个钻孔获取信息来确定弱透水层的完整性，第二个是将这种方法应用于两个重要的粘土弱透水层的调查：一个位于安大略西南部，另一个位于温尼伯。 新方法包括四项活动的组合：旋转声波钻井，在旋转声波孔中安装新型监测装置，从旋转声波岩心中挤出孔隙水，以及使用岩心X射线照相术。 由于钻井/取芯技术的最新进展和多级监测技术的进步，可以从同一个孔中获得许多信息。 三种主要的数据类型是详细的水头剖面、环境同位素（即氚、18 O、2 H、碳-14）和弱透水层岩心的X射线照相。X射线照相术是一种已经存在了几十年的技术，但在弱透水层完整性研究中很少使用，我相信它会增加很多价值。 其他更传统的数据也将从孔中获得，但主要的新见解和有关弱透水层完整性的整体价值预计将来自上述组合。旋转声波钻探以合理的成本在几乎所有类型的非硬化矿床中提供大直径岩心，并且岩心孔很容易用于安装头部轮廓的多级监测系统。此外，岩心通过挤压提供水用于同位素和其他分析。

Contamination of aquifers is an increasing problem globally and in many regions. The degree and timing of the contamination is governed by the characteristics of the aquitard (low permeability layer) that overlies the aquifer. Aquitard integrity refers to the capability of the aquitard to protect the underlying aquitard from contamination. This research has two goals: the first is to develop a new method for determining aquitard integrity by acquiring information from a single drill hole at each study location, and the second is to apply this method in an investigation of two important clayey aquitards: one located in southwestern Ontario and the other in Winnipeg. The new method involves a combination of four activities: rotosonic drilling, installation of a new type of monitoring device in the rotosonic holes, squeezing of porewater from the rotosonic cores, and the use of x-radiography of cores. Much information can be obtained from the same hole because of recent advances in drilling / coring technology and advances in multilevel monitoring technology. The three main data types are detailed hydraulic head profiles, environmental isotopes (i.e. tritium, 18O, 2H, carbon-14) and X-radiography of aquitard cores. X-radiography is a technique that has existed for many decades but it has been little used in studies of aquitard integrity and I believe it will add much value. Other more conventional data will also be obtained from the holes, however the major new insights and overall value concerning aquitard integrity are expected to come from the above- mentioned combination. Rotosonic drilling provides large-diameter core at reasonable cost in essentially all types of nonindurated deposits and the core holes are easily used for installation of multilevel monitoring systems for head profiles. Also, the cores provide water by squeezing for isotope and other analyses.