Air flow paths and porosity/permeability change in a saturated zone during in situ air sparging

2007 ◽  
Vol 142 (1-2) ◽  
pp. 315-323 ◽  
Author(s):  
Yih-Jin Tsai
2001 ◽  
Author(s):  
Richard L. Johnson ◽  
Paul C. Johnson ◽  
Tim L. Johnson ◽  
Neil Thomas ◽  
Andrea Leason

2005 ◽  
Author(s):  
P. M. Mohan Das ◽  
R. S. Amano ◽  
T. Roy ◽  
J. Jatkar

Heated Soil Vapor Extraction (HSVE), developed by Advanced Remedial Technology is a Soil remediation process that has gained significant attention during the past few years. HSVE along with Air sparging has been found to be an effective way of remediating soil of various pollutants including solvents, fuels and Para-nuclear aromatics. The combined system consists of a heater/boiler that pumps and circulates hot oil through heating wells, a blower that helps to suck the contaminants out through the extraction well, and air sparging wells that extend down to the saturated region in the soil. Both the heating wells and extraction wells are installed vertically in the saturated region in contaminated soil and is welded at the bottom and capped at the top. The heat source heats the soil and the heat is transported inside the soil by means of conduction and convection. This heating of soil results in vaporization of the gases, which are then absorbed by the extraction well. Soil vapor extraction cannot remove contaminants in the saturated zone of the soil that lies below the water table. In that case air sparging may be used. In air sparging system, air is pumped into the saturated zone to help flush the contaminants up into the unsaturated zone where the contaminants are removed by SVE well. In this analysis an attempt has been made to predict the behavior of different chemicals in the unsaturated and saturated regions of the soil. This analysis uses the species transport and discrete phase modeling to predict the behavior of different chemicals when it is heated and absorbed by the extraction well. Such an analysis will be helpful in predicting the parameters like the distance between the heating and extraction wells, the temperature to be maintained at the heating well and the time required for removing the contaminants from the soil.


2022 ◽  
Author(s):  
Ziyan Li ◽  
Derek Elsworth ◽  
Chaoyi Wang

Abstract Fracturing controls rates of mass, chemical and energy cycling within the crust. We use observed locations and magnitudes of microearthquakes (MEQs) to illuminate the evolving architecture of fractures reactivated and created in the otherwise opaque subsurface. We quantitatively link seismic moments of laboratory MEQs to the creation of porosity and permeability at field scale. MEQ magnitudes scale to the slipping patch size of remanent fractures reactivated in shear - with scale-invariant roughnesses defining permeability evolution across nine decades of spatial volumes – from centimeter to decameter scale. This physics-inspired seismicity-permeability linkage enables hybrid machine learning (ML) to constrain in-situ permeability evolution at verifiable field-scales (~10 m). The ML model is trained on early injection and MEQ data to predict the dynamic evolution of permeability from MEQ magnitudes and locations, alone. The resulting permeability maps define and quantify flow paths verified against ground truths of permeability.


1994 ◽  
Vol 56 (1-4) ◽  
pp. 263-266 ◽  
Author(s):  
E.O. Knutson ◽  
A.C. George ◽  
P. Shebell ◽  
C.V. Gogolak

Abstract The Environmental Measurements Laboratory's experience with two methods of measuring thoron gas, and its findings on the feasibility of using these measurements to diagnose indoor air flow paths, are presented. One method is an updated version of the two-filter tube, and the other is a modified Falk-More-Nyblom delayed coincidence method. Measurements made with these instruments in six houses indicated that thoron concentrations are very low (median about 11 Bq.m-3); this is consistent with values previously reported for US housing. Both methods had difficulty measuring these low levels, particularly in houses with high radon gas levels. At one house, thoron levels measured outdoors over bare earth were higher than indoor levels. At the low levels encountered and with the current measuring technology, it seems unlikely that thoron gas measurements can be used to trace indoor air motion.


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