DOI: 10.5194/hess-20-39-2016
Scopus记录号: 2-s2.0-84961339512
论文题名: Accelerated gravity testing of aquitard core permeability and implications at formation and regional scale
作者: Timms W ; A ; , Crane R ; , Anderson D ; J ; , Bouzalakos S ; , Whelan M ; , McGeeney D ; , Rahman P ; F ; , Acworth R ; I
刊名: Hydrology and Earth System Sciences
ISSN: 10275606
出版年: 2016
卷: 20, 期: 1 起始页码: 39
结束页码: 54
语种: 英语
Scopus关键词: Aquifers
; Centrifuges
; Deionized water
; Groundwater flow
; Hydrogeology
; Solute transport
; Water conservation
; Water supply
; Centrifuge permeameter
; Confidence interval
; Geochemical reaction
; Geotechnical centrifuges
; Hydraulic connectivity
; Pressure propagation
; Sustainable water supply
; Vertical hydraulic conductivities
; Core samples
; aquitard
; centrifuge
; flow modeling
; flow velocity
; geophysical method
; gravity field
; heterogeneity
; hydraulic conductivity
; hydrogeology
; leakage
; permeability
; pore pressure
; porosity
; solute transport
; steady-state equilibrium
; Bos
英文摘要: Evaluating the possibility of leakage through lowpermeability geological strata is critically important for sustainable water supplies, the extraction of fuels from coal and other strata, and the confinement of waste within the earth. The current work demonstrates that relatively rapid and realistic vertical hydraulic conductivity (Kv) measurements of aquitard cores using accelerated gravity can constrain and compliment larger-scale assessments of hydraulic connectivity. Steady-state fluid velocity through a low-K porous sample is linearly related to accelerated gravity (g level) in a centrifuge permeameter (CP) unless consolidation or geochemical reactions occur. A CP module was custom designed to fit a standard 2m diameter geotechnical centrifuge (550 g maximum) with a capacity for sample dimensions up to 100mm diameter and 200mm length, and a total stress of ∼ 2MPa at the base of the core. Formation fluids were used as influent to limit any shrink-swell phenomena, which may alter the permeability. Kv results from CP testing of minimally disturbed cores from three sites within a clayey-silt formation varied from 10-10 to 10-7 ms-1 (number of samples, n = 18). Additional tests were focussed on the Cattle Lane (CL) site, where Kv within the 99% confidence interval (n = 9) was 1.1 × 10-9 to 2.0 × 10-9 ms-1. These Kv results were very similar to an independent in situ Kv method based on pore pressure propagation though the sequence. However, there was less certainty at two other core sites due to limited and variable Kv data. Blind standard 1 g column tests underestimated Kv compared to CP and in situ Kv data, possibly due to deionised water interactions with clay, and were more time-consuming than CP tests. Our Kv results were compared with the set-up of a flow model for the region, and considered in the context of heterogeneity and preferential flow paths at site and formation scale. Reasonable assessments of leakage and solute transport through aquitards over multi-decadal timescales can be achieved by accelerated core testing together with complimentary hydrogeological monitoring, analysis, and modelling. © 2016 Author(s). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/78949
Appears in Collections: 气候变化事实与影响
There are no files associated with this item.
作者单位: School of Mining Engineering, University of New South Wales, Sydney, Australia; UNSW, National Centre for Groundwater Research and Training, Sydney, Australia; Water Research Laboratory, School of Civil and Environmental Engineering, University of New South Wales, Sydney, Australia
Recommended Citation:
Timms W,A,, Crane R,et al. Accelerated gravity testing of aquitard core permeability and implications at formation and regional scale[J]. Hydrology and Earth System Sciences,2016-01-01,20(1)