A field proof-of-concept of aquifer imaging using 3-D transient hydraulic tomography with modular, temporarily-emplaced equipment
A field proof-of-concept of aquifer imaging using 3-D transient hydraulic tomography with modular, temporarily-emplaced equipment
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DOI：
10.1029/2011wr011704
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发表时间：
2012-05-19
影响因子：
5.4
通讯作者：
Kitanidis, P. K.
中科院分区：
文献类型：
--
作者：
Cardiff, M.;Barrash, W.;Kitanidis, P. K.
水力层析成像是一种现场尺度的含水层表征方法，能够估计三维非均质参数分布，并且对水力导率(K)直接敏感，因此为改进流动和输送模型提供了有用的数据源。我们展示了一个概念验证和建模研究的结果，我们将三维瞬态水力断层扫描（3DTHT）应用于博伊西水文地球物理研究基地相对高k和中等非均质无承压含水层。采用短时间（20分钟）部分穿透抽水试验作为含水层增产措施，观察到的响应未达到稳定状态。为了收集现场数据，我们使用临时放置的封隔器设备系统来隔离井眼中的多个离散层段。为了分析数据，我们使用MODFLOW结合基于Kitanidis（1995）拟线性方法的地统计反演代码。这种实用软件的组合允许对大型数据集（bbb250下降曲线和近1000个单独的数据点）进行反演，并在> 100,000个位置估计K；合理的运行时使用单个多核计算机与12 GB的RAM。3DTHT的K非均质性结果与大量部分穿透段塞测试的K表征进行了交叉验证，发现两者非常一致。使用便携式模块化设备进行现场实施意味着可以在几天内进行3DTHT数据收集（包括动员/复员）。同样，使用实用、高效和可扩展的数值模拟和反演策略意味着计算工作量大大减少，从而可以快速估计三维含水层性质分布。
Hydraulic tomography is a field scale aquifer characterization method capable of estimating 3-D heterogeneous parameter distributions, and is directly sensitive to hydraulic conductivity (K), thus providing a useful data source for improving flow and transport models. We present results from a proof-of-concept field and modeling study in which we apply 3-D transient hydraulic tomography (3DTHT) to the relatively high-K and moderately heterogeneous unconfined aquifer at the Boise Hydrogeophysical Research Site. Short-duration (20 min) partially penetrating pumping tests, for which observed responses do not reach steady state, are used as the aquifer stimulation. To collect field data, we utilize a system of temporarily emplaced packer equipment to isolate multiple discrete intervals in boreholes. To analyze the data, we utilize MODFLOW combined with geostatistical inversion code based on the quasilinear approach of Kitanidis (1995). This combination of practical software allows inversion of large datasets (>250 drawdown curves, and almost 1000 individual data points) and estimation of K at > 100,000 locations; reasonable runtimes are obtained using a single multicore computer with 12 GB of RAM. The K heterogeneity results from 3DTHT are cross-validated against K characterization from a large set of partially penetrating slug tests, and found to be quite consistent. The use of portable, modular equipment for field implementation means that 3DTHT data collection can be performed (including mobilization/demobilization) within a matter of days. Likewise, use of a practical, efficient and scalable numerical modeling and inversion strategy means that computational effort is drastically reduced, such that 3-D aquifer property distributions can be estimated quickly.