Schweisinger Todd, Svenson Erik J, Murdoch Lawrence C
Department of Environmental Engineering & Earth Sciences, 340 Brackett Hall, Clemson University, Clemson, SC 29634, USA.
Ground Water. 2009 Jan-Feb;47(1):69-79. doi: 10.1111/j.1745-6584.2008.00501.x. Epub 2008 Sep 23.
This article introduces hydromechanical well tests as a viable field method for characterizing fractured rock aquifers. These tests involve measuring and analyzing small displacements along with pressure transients. Recent developments in equipment and analyses have simplified hydromechanical well tests, and this article describes initial field results and interpretations during slug and constant-rate pumping tests conducted at a site underlain by fractured biotite gneiss in South Carolina. The field data are characterized by displacements of 0.3 microm to more than 10 microm during head changes up to 10 m. Displacements are a hysteretic function of hydraulic head in the wellbore, with displacements late in a well test always exceeding those at similar wellbore pressures early in the test. Displacement measurements show that hydraulic aperture changes during well tests, and both scaling analyses and field data suggest that T changed by a few percent per meter of drawdown during slug and pumping tests at our field site. Preliminary analyses suggest that displacement data can be used to improve estimates of storativity and to reduce nonuniqueness during hydraulic well tests involving single wells.
本文介绍了水力-力学试井，它是一种用于表征裂隙岩石含水层的可行现场方法。这些测试包括测量和分析微小位移以及压力瞬变。设备和分析方面的最新进展简化了水力-力学试井，本文描述了在南卡罗来纳州一处由裂隙黑云母片麻岩构成的场地进行的活塞式和定流量抽水试验期间的初步现场结果及解释。现场数据的特征是，在水头变化高达10米的情况下，位移范围为0.3微米至超过10微米。位移是井筒中水头的滞后函数，试井后期的位移总是超过试验早期类似井筒压力下的位移。位移测量表明，试井期间水力孔径会发生变化，标度分析和现场数据均表明，在我们的现场场地进行活塞式和抽水试验时，每下降一米，导水系数T会变化百分之几。初步分析表明，位移数据可用于改进储水系数的估计，并减少单井水力试井期间的非唯一性。
