scholarly journals Characterization of preferential flow paths between boreholes in fractured rock using a nanoscale zero-valent iron tracer test

2016 ◽  
Vol 24 (7) ◽  
pp. 1651-1662 ◽  
Author(s):  
Po-Yu Chuang ◽  
Yeeping Chia ◽  
Ya-Hsuan Liou ◽  
Mao-Hua Teng ◽  
Ching-Yi Liu ◽  
...  
Keyword(s):  
Preferential Flow ◽  
Fractured Rock ◽  
Tracer Test ◽  
Zero Valent Iron ◽  
Flow Paths ◽  
Preferential Flow Paths ◽  
Nanoscale Zero Valent Iron

scholarly journals Structural geology and geophysics as a support to build a hydrogeologic model of granite rock

Solid Earth ◽  
2016 ◽  
Vol 7 (3) ◽  
pp. 881-895 ◽  
Author(s):  
Lurdes Martinez-Landa ◽  
Jesús Carrera ◽  
Andrés Pérez-Estaún ◽  
Paloma Gómez ◽  
Carmen Bajos
Keyword(s):  
Structural Geology ◽  
Large Scale ◽  
Preferential Flow ◽  
Three Dimensional ◽  
Pumping Test ◽  
Discrete Elements ◽  
Flow Paths ◽  
Preferential Flow Paths

Abstract. A method developed for low-permeability fractured media was applied to understand the hydrogeology of a mine excavated in a granitic pluton. This method includes (1) identifying the main groundwater-conducting features of the medium, such as the mine, dykes, and large fractures, (2) implementing this factors as discrete elements into a three-dimensional numerical model, and (3) calibrating these factors against hydraulic data . A key question is how to identify preferential flow paths in the first step. Here, we propose a combination of several techniques. Structural geology, together with borehole sampling, geophysics, hydrogeochemistry, and local hydraulic tests aided in locating all structures. Integration of these data yielded a conceptual model of the site. A preliminary calibration of the model was performed against short-term (< 1 day) pumping tests, which facilitated the characterization of some of the fractures. The hydraulic properties were then used for other fractures that, according to geophysics and structural geology, belonged to the same families. Model validity was tested by blind prediction of a long-term (4 months) large-scale (1 km) pumping test from the mine, which yielded excellent agreement with the observations. Model results confirmed the sparsely fractured nature of the pluton, which has not been subjected to glacial loading–unloading cycles and whose waters are of Na-HCO3 type.

scholarly journals New method for the characterization of three-dimensional preferential flow paths in the field

2010 ◽  
Vol 46 (2) ◽  
Author(s):  
Majdi R. Abou Najm ◽  
Jalal D. Jabro ◽  
William M. Iversen ◽  
Rabi H. Mohtar ◽  
Robert G. Evans
Keyword(s):  
Preferential Flow ◽  
Three Dimensional ◽  
New Method ◽  
Flow Paths ◽  
Preferential Flow Paths

scholarly journals Mapping fracture flow paths with a nanoscale zero-valent iron tracer test and a flowmeter test

2017 ◽  
Vol 26 (1) ◽  
pp. 321-331 ◽  
Author(s):  
Po-Yu Chuang ◽  
Yeeping Chia ◽  
Yung-Chia Chiu ◽  
Mao-Hua Teng ◽  
Sofia Ya Hsuan Liou
Keyword(s):  
Tracer Test ◽  
Zero Valent Iron ◽  
Fracture Flow ◽  
Flow Paths ◽  
Flowmeter Test ◽  
Nanoscale Zero Valent Iron

Characterization of Preferential Flow Paths in Compacted Sand-Clay Mixtures

1995 ◽  
Vol 121 (9) ◽  
pp. 652-659 ◽  
Author(s):  
Rao S. Govindaraju ◽  
Lakshmi N. Reddi ◽  
Shashikanth K. Bhargava
Keyword(s):  
Preferential Flow ◽  
Flow Paths ◽  
Preferential Flow Paths

scholarly journals Structural geology and geophysics as a key to build a hydrogeologic model of granite rock to support a mine

2016 ◽  
Author(s):  
L. Martinez Landa ◽  
J. Carrera ◽  
A. Perez-Estaún ◽  
P. Gomez ◽  
C. Bajos
Keyword(s):  
Structural Geology ◽  
Large Scale ◽  
Preferential Flow ◽  
Three Dimensional ◽  
Pumping Test ◽  
Discrete Elements ◽  
Flow Paths ◽  
Preferential Flow Paths

Abstract. A methodology developed for low permeability fractured media has been applied to understand the hydrogeology of a mine excavated in a granitic pluton. This methodology consists of (1) identifying the main ground water conducting features of the medium, such as the mine, dykes and large fractures, (2) implementing them as discrete elements into a three-dimensional numerical model, and (3) calibrating them against hydraulic data (Martínez-Landa and Carrera, 2005b). The key question is how to identify preferential flow paths in the first step. Here, we propose a combination of several techniques. Structural geology, together with borehole samples, geophysics, hydrogeochemistry and local hydraulic tests aided in locating all structures. Integrating these data yields a conceptual model of the site. A preliminary calibration of the model was performed against short-term (less than a day) pumping tests, which helped in the characterization of some fractures. Their hydraulic properties were then used for other fractures that, according to geophysics and structural geology, belonged to the same families. Model validity was tested by blind prediction of a long-term (4 months) large-scale (1 km) pumping test from the mine, which yielded an excellent agreement with observations. Model results confirm the sparsely fractured nature of the pluton, which has not been subjected to glacial loading-unloading cycles and whose waters are of Na-HCO3 type.

Visualizing Preferential Flow Paths using Ammonium Carbonate and a pH Indicator

2002 ◽  
Vol 66 (2) ◽  
pp. 347 ◽  
Author(s):  
Zhi Wang ◽  
Jianhang Lu ◽  
Laosheng Wu ◽  
Thomas Harter ◽  
William A. Jury
Keyword(s):  
Preferential Flow ◽  
Ammonium Carbonate ◽  
Ph Indicator ◽  
Flow Paths ◽  
Preferential Flow Paths

Equation for Describing Solute Transport in Field Soils with Preferential Flow Paths

2005 ◽  
Vol 69 (2) ◽  
pp. 291-300 ◽  
Author(s):  
Young-Jin Kim ◽  
Christophe J. G. Darnault ◽  
Nathan O. Bailey ◽  
J.-Yves Parlange ◽  
Tammo S. Steenhuis
Keyword(s):  
Solute Transport ◽  
Preferential Flow ◽  
Flow Paths ◽  
Preferential Flow Paths ◽  
Field Soils

Dynamic Modeling of Channel Formation During Fluid Injection Into Unconsolidated Formations

SPE Journal ◽  
2015 ◽  
Vol 20 (04) ◽  
pp. 689-700 ◽  
Author(s):  
S.. Ameen ◽  
A. Dahi Taleghani
Keyword(s):  
Preferential Flow ◽  
Volume Fraction ◽  
Injection Pressure ◽  
Internal Erosion ◽  
Fluid Injection ◽  
Critical Threshold ◽  
Model Parameters ◽  
Flow Paths ◽  
Preferential Flow Paths ◽  
Stress Changes

Summary Injectivity loss is a common problem in unconsolidated-sand formations. Injection of water into a poorly cemented granular medium may lead to internal erosion, and consequently formation of preferential flow paths within the medium because of channelization. Channelization in the porous medium might occur when fluid-induced stresses become locally larger than a critical threshold and small grains are dislodged and carried away; hence, porosity and permeability of the medium will evolve along the induced flow paths. Vice versa, flowback during shut-in might carry particles back to the well and cause sand accumulation inside the well, and subsequently loss of injectivity. In most cases, to maintain the injection rate, operators will increase injection pressure and pumping power. The increased injection pressure results in stress changes and possibly further changes in channel patterns around the wellbore. Experimental laboratory studies have confirmed the presence of the transition from uniform Darcy flow to a fingered-pattern flow. To predict these phenomena, a model is needed to fill this gap by predicting the formation of preferential flow paths and their evolution. A model based on the multiphase-volume-fraction concept is used to decompose porosity into mobile and immobile porosities where phases may change spatially, evolve over time, and lead to development of erosional channels depending on injection rates, viscosity, and rock properties. This model will account for both particle release and suspension deposition. By use of this model, a methodology is proposed to derive model parameters from routine injection tests by inverse analysis. The proposed model presents the characteristic behavior of unconsolidated formation during fluid injection and the possible effect of injection parameters on downhole-permeability evolution.

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