Using excess 4He to quantify variability in aquitard leakage

Gardner, W. Payton; Harrington, Glenn A.; Smerdon, Brian

doi:10.1016/j.jhydrol.2012.08.014

Cited by 26 publications

(27 citation statements)

References 42 publications

(67 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Alternatively, isotopic signatures in pore fluids could provide valuable information of seal effectiveness by identifying the chemical reactivity and the age of fluids within caprocks (Gale et al 2007;Lu et al 2009). In addition, He isotope techniques in conjunction with 14 C, Ne, Ar, and N 2 have been applied to quantify the diffusive flux through the sealing unit (Marty et al 2003;Hendry et al 2005;Battani et al 2011;Mazurek et al 2011;Gardner et al 2012). From the vertical profile of δ 13 C isotope, the infiltration rate (∼9.8 × 10 −7 g/m 2 /year) of the naturally stored CO 2 was estimated, suggesting the successful application of isotope techniques for predicting seal integrity of CO 2 storage formations.…”

Section: Seal Integrity Quantification Using He Concentration and Itsmentioning

confidence: 99%

Transport of Groundwater, Heat, and Radiogenic He in Topography‐Driven Basins

Han

Kim²,

Jung

et al. 2014

Groundwater

View full text Add to dashboard Cite

The goal of the study is to assess the feasibility of characterizing the caprock integrity by utilizing sampled helium (He) concentration in fluids and temperature measurement prior to CO2 injection. A series of simulations representing pre-CO2 injection phase was conducted to reveal the spatial distribution of groundwater, temperature, and He concentration under various geologic conditions of topographically driven basin. Then, their profiles in preinjection conditions were compared with dynamic signatures of both injection-induced pressure and leaked brine concentration at post-CO2 injection conditions. In the topographic basin, He and heat transports generally show analogous transport except the low-permeability basin where the conductive heat and diffusive solute transports are the primary transport mechanisms. The transition occurred at permeabilities between 10(-15) and 10(-14) m2. Inclusion of low-k layer (low-k layer: 10(-16) m2 and surrounding basin: 10(-13) m2) segregates shallow and deep groundwater system and creates a 3-km single large free convection of groundwater driven by unevenly distributed thermal profile of basin. Finally, He and temperature profiles with high-k pathways at pre-CO2 injection scenarios and NaCl mass fractions at post-CO2 injection showed systematic trends and relationships, suggesting that proper understanding of these trends will aid to identify the seal integrity.

show abstract

Section: Seal Integrity Quantification Using He Concentration and Itsmentioning

confidence: 99%

Transport of Groundwater, Heat, and Radiogenic He in Topography‐Driven Basins

Han

Kim²,

Jung

et al. 2014

Groundwater

View full text Add to dashboard Cite

show abstract

“…Numerous tracers have been used to assess fluid flow rates in aquitards (Gimmi et al 2007;Hendry et al 2011;Mazurek et al 2011;Gardner et al 2012;Smith 2015). The present study examines the use of helium ( 4 He), which is completely inert and is produced in the radioactive decay of uranium (U) and thorium (Th).…”

Section: Introductionmentioning

confidence: 99%

Quartz‐Helium Method to Estimate Fluid Flow in Thick Aquitards, Gunnedah Basin, Australia

2018

View full text Add to dashboard Cite

The hydraulic integrity of aquitards is generally assumed and relies on a few core-scale permeability measurements, drill-stem tests, or textbook values. This approach is because hydraulic data across the full aquitard thickness is generally lacking. Proper assessment of aquitard integrity should be studied at the formation (spanning its entire thickness at a single point) or regional (formation properties at multiple locations throughout the basin) scale. One formation-scale approach uses environmental tracers and advection-dispersion modeling to constrain fluid flow rates. This study demonstrates the use of helium concentrations in quartz as a method of constraining the rate of fluid flow in a 520-m thick aquitard in the Gunnedah Basin, NSW, Australia. Quartz was separated from existing core samples in the Watermark and Porcupine Formations at depths from 750 to 1200 m. The helium was released from these samples by heating and select samples were impregnated with helium to determine the rate of helium diffusion through the quartz. One-dimensional advection-dispersion modeling of the helium profile accounting for diffusive helium exchange between quartz and pore water revealed, that (1) vertical fluid velocity has been on the order of 0.02 mm/year or less for tens to thousands of years, (2) helium is in equilibrium between quartz and pore water, and (3) the helium profile is transient indicating that helium concentrations in the underlying Maules Creek Formation has varied over geological time. Further modeling identified aquitard conditions (thickness and temperature) for which equilibrium exists, a precondition for deriving formation-scale permeability.

show abstract

“…These tracers represent natural analogues that provide a means to determine mass transport characteristics of solutes (e.g., radionuclides) over geologic time scales [6][7][8][9][10]. In various studies, helium isotopes have been used to quantify fluxes in low permeability media and to determine media properties [6,[11][12][13][14][15]. Helium in groundwater originates from the natural radioactive decay of uranium and thorium and from degassing of the crust and mantle [16,17].…”

Section: Introductionmentioning

confidence: 99%

Assessing Alternative Scenarios for the Cause of Underpressures in the Ordovician Sediments along the Eastern Flank of the Michigan Basin

et al. 2017

View full text Add to dashboard Cite

Geoscientific investigations for a proposed deep geologic repository at the Bruce Site, located on the eastern flank of the Michigan Basin, have identified unique and significant underpressured conditions. Along with the measurement of environmental tracer profiles (e.g., helium), this study aims to explore, through a series of numerical simulations, the nature of long-term phenomena responsible for the generation and preservation of formation underpressures. Three families of inverse numerical experiments for underpressure formation were examined by means of one-dimensional hydromechanically coupled models through the vertical hydrostratigraphic column: (i) uncertainty in glaciation scenarios; (ii) uncertainty in initial heads prior to glaciation; and (iii) uncertainty in the degree of hydraulic connectivity between the more permeable Guelph Formation at the Bruce Site and the applied glacial loading, for a total of 20 scenarios, assuming fully saturated conditions. Underpressured initial heads for the paleohydrogeologic simulations lead to lower calibrated vertical hydraulic conductivities. The robustness and resilience of the groundwater system to external perturbations are greater for the state where underpressured conditions predate the onset of glaciation and are better able to preserve the present day helium tracer profile in 260 Ma exhumation analyses.

show abstract

Using excess 4He to quantify variability in aquitard leakage

Cited by 26 publications

References 42 publications

Transport of Groundwater, Heat, and Radiogenic He in Topography‐Driven Basins

Transport of Groundwater, Heat, and Radiogenic He in Topography‐Driven Basins

Quartz‐Helium Method to Estimate Fluid Flow in Thick Aquitards, Gunnedah Basin, Australia

Assessing Alternative Scenarios for the Cause of Underpressures in the Ordovician Sediments along the Eastern Flank of the Michigan Basin

Contact Info

Product

Resources

About