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Changes in Geochemical Composition of Groundwater Due to CO2 Leakage in Various Geological Media. WATER 2020. [DOI: 10.3390/w12092597] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This study evaluated the effects of CO2 leakage on the geochemical composition of groundwater in various geological media through long-term column experiments. Four columns were set up with soil representing a silicate aquifer; clean sand; a sand and limestone mixture; and alluvium soil, respectively. The experiments were conducted under the same experimental conditions for approximately one year. As the CO2-saturated synthetic groundwater was introduced into the columns, a decrease in pH and increases in electrical conductivity (EC), alkalinity, and concentrations of cations and trace elements were observed in all geological media. However, different patterns of changes were also observed depending on the mineralogical and physico-chemical characteristics of each material. As the column operation continued, while the pH decreased and low alkalinity values were more evident in the silicate soil and clean sand columns, the carbonate column continued to show high alkalinity and EC values in addition to high concentrations of most cations. The alluvium soil showed distinctive cation-exchange behaviors during the initial introduction of CO2. The results indicate that changes in the geochemical composition of groundwater will depend on the characteristic of the geological medium such as pH buffering capacity and cation exchange capacity. This study can be useful for monitoring and managing the impacts of CO2 leakage in various aquifer environments.
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2
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Berger PM, Wimmer B, Iranmanesh A. Sensitivity thresholds of groundwater parameters for detecting CO 2 leakage at a geologic carbon sequestration site. ENVIRONMENTAL MONITORING AND ASSESSMENT 2019; 191:685. [PMID: 31659477 DOI: 10.1007/s10661-019-7880-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 10/10/2019] [Indexed: 06/10/2023]
Abstract
Geologic carbon sequestration (GCS) projects in the USA are required to monitor groundwater quality for geochemical changes above the injection area that may be a result of CO2 or brine leakage from the storage reservoir. Should CO2 migrate into the groundwater around the compliance wells monitoring the shallower hydrologic units, each compliance parameter could react differently depending on its sensitivity to CO2. Statistically determined limits (SDLs) for detection of CO2 leakage into groundwater were calculated using background water quality data from the Illinois Basin Decatur Project (IBDP) sequestration site and prediction and tolerance intervals for specific compliance parameters. If the parameter concentrations varied outside of these ranges during the injection and post injection periods of a GCS project, then additional actions would be required to determine the reason for the changes in groundwater concentrations. Geochemical modeling can simulate the amount of CO2 needed to alter water quality parameters a statistically significant amount. This information can then inform GCS operators and regulators as to which compliance parameters are relevant (sensitive) to CO2 leakage for a given setting. For the system studied in here, Fe, Ca, K, Mg, CO2, and pH were sensitive to CO2 addition while Al, Cl, Na, and Si were not.
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Affiliation(s)
- Peter M Berger
- CODES, University of Tasmania, Private Bag 79, Hobart, Tasmania, 7001, Australia.
- Illinois State Geological Survey, 615 E. Peabody Dr, Champaign, IL, 61820, USA.
| | - Bracken Wimmer
- Illinois State Geological Survey, 615 E. Peabody Dr, Champaign, IL, 61820, USA
| | - Abbas Iranmanesh
- Illinois State Geological Survey, 615 E. Peabody Dr, Champaign, IL, 61820, USA
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3
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Unstable, Super Critical CO 2-Water Displacement in Fine Grained Porous Media under Geologic Carbon Sequestration Conditions. Sci Rep 2019; 9:11272. [PMID: 31375705 PMCID: PMC6677758 DOI: 10.1038/s41598-019-47437-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Accepted: 05/29/2019] [Indexed: 11/22/2022] Open
Abstract
In this study we investigated fluid displacement water with supercritical (sc) CO2 in chalk under conditions close to those used for geologic CO2 sequestration (GCS), to answer two main questions: How much volume is available for scCO2 injection? And what is the main mechanism of displacement over a range of temperatures? Characterization of immiscible scCO2 displacement, at the pore scale in the complex microstructure in chalk reservoirs, offers a pathway to better understand the macroscopic processes at the continuum scale. Fluid behavior was simulated by solving the Navier-Stokes equations, using finite-volume methods within a pore network. The pore network was extracted from a high resolution 3D image of chalk, obtained using X-ray nanotomography. Viscous fingering dominates scCO2 infiltration and pores remain only partially saturated. The unstable front, developed with high capillary number, causes filling of pores aligned with the flow direction, reaching a maximum of 70% scCO2 saturation. The saturation rate increases with temperature but the final saturation state is the same for all investigated temperatures. The higher the saturation rate, the higher the dynamic capillary pressure coefficient. A higher dynamic capillary pressure coefficient indicates that scCO2 needs more time to reach capillary equilibrium in the porous medium.
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4
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Lv H, Su X, Wang Y, Dai Z, Liu M. Effectiveness and mechanism of natural attenuation at a petroleum-hydrocarbon contaminated site. CHEMOSPHERE 2018; 206:293-301. [PMID: 29753292 DOI: 10.1016/j.chemosphere.2018.04.171] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 04/26/2018] [Accepted: 04/28/2018] [Indexed: 06/08/2023]
Abstract
This study applied an integrated method for evaluating the effectiveness and mechanism of natural attenuation (NA) of petroleum-hydrocarbon contaminated groundwater. Site groundwater and soil samples were analysed to characterize spatial and temporal variations in petroleum hydrocarbons, geochemical indicators, microbial diversity and isotopes. The results showed that the area of petroleum hydrocarbon contamination plume decreased almost 60% in four years, indicating the presence of natural attenuation. The 14C content and sequence analysis indicate that there are more relatively 'old' HCO3- that have been produced from petroleum hydrocarbons in the upgradient portion of the contaminated plume, confirming that intrinsic biodegradation was the major factor limiting spread of the contaminated plume. The main degradation mechanisms were identified as sulfate reduction and methanogenesis based on the following: (1) more SO42- have been consumed in the contamination source than downgradient, and the δ34S values in the resident SO42- were also more enriched in the contamination source, (2) production of more CH4 in the contamination source with the δ13C values for CH4 was much lower than that of CO2, and the fractionation factor was 1.030-1.046. The results of this study provide significant insight for applying natural attenuation and enhanced bioremediation as alternative options for remediation of petroleum-hydrocarbon contaminated sites.
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Affiliation(s)
- Hang Lv
- Key Laboratory of Groundwater Resources and Environment, Ministry of Education/Institute of Water Resources and Environment, Jilin University, Changchun 130026, PR China; Engineering Research Center of Groundwater Pollution Control and Remediation, Ministry of Education, Beijing 100875, PR China
| | - Xiaosi Su
- College of Construction Engineering, Jilin University, Changchun 130026, PR China
| | - Yan Wang
- College of Construction Engineering, Jilin University, Changchun 130026, PR China.
| | - Zhenxue Dai
- College of Construction Engineering, Jilin University, Changchun 130026, PR China
| | - Mingyao Liu
- Geological Survey of Jiangsu Province, Nanjing 210018, PR China; Key Laboratory of Earth Fissures Geological Disaster, Ministry of Land and Resources, Nanjing 210018, PR China
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Zhao X, Deng H, Wang W, Han F, Li C, Zhang H, Dai Z. Impact of naturally leaking carbon dioxide on soil properties and ecosystems in the Qinghai-Tibet plateau. Sci Rep 2017; 7:3001. [PMID: 28592834 PMCID: PMC5462800 DOI: 10.1038/s41598-017-02500-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 04/12/2017] [Indexed: 11/08/2022] Open
Abstract
One of the major concerns for CO2 capture and storage (CCS) is the potential risk of CO2 leakage from storage reservoirs on the shallow soil property and vegetation. This study utilizes a naturally occurring CO2 leaking site in the Qinghai-Tibet Plateau to analog a "leaking CCS site". Our observations from this site indicates that long-term CO2 invasion in the vadose zone results in variations of soil properties, such as pH fluctuation, slight drop of total organic carbon, reduction of nitrogen and phosphorus, and concentration changes of soluble ions. Simultaneously, XRD patterns of the soil suggest that crystallization of soil is enhanced and mineral contents of calcite and anorthite in soil are increased substantially. Parts of the whole ecosystem such as natural wild plants, soil dwelling animals and microorganisms in shallow soil are affected as well. Under a moderate CO2 concentration (less than 110000 ppm), wild plant growth and development are improved, while an intensive CO2 flux over 112000 ppm causes adverse effects on the plant growth, physiological and biochemical system of plants, and crop quality of wheat. Results of this study provide valuable insight for understanding the possible environmental impacts associated with potential CO2 leakage into shallow sediments at carbon sequestration sites.
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Affiliation(s)
- Xiaohong Zhao
- Key Laboratory of Subsurface Hydrology and Ecology in Arid Areas, Ministry of Education, Chang'an University, Xi'an, 710054, P. R. China
| | - Hongzhang Deng
- Key Laboratory of Subsurface Hydrology and Ecology in Arid Areas, Ministry of Education, Chang'an University, Xi'an, 710054, P. R. China
| | - Wenke Wang
- Key Laboratory of Subsurface Hydrology and Ecology in Arid Areas, Ministry of Education, Chang'an University, Xi'an, 710054, P. R. China.
| | - Feng Han
- Key Laboratory of Subsurface Hydrology and Ecology in Arid Areas, Ministry of Education, Chang'an University, Xi'an, 710054, P. R. China
| | - Chunrong Li
- Key Laboratory of Subsurface Hydrology and Ecology in Arid Areas, Ministry of Education, Chang'an University, Xi'an, 710054, P. R. China
| | - Hui Zhang
- Center for Hydrogeology and Environmental Geology Survey, CGS, Hebei Baoding, 071051, P. R. China
| | - Zhenxue Dai
- Los Alamos National Laboratory, Los Alamos, New Mexico, 87544, USA.
- College of Construction Engineering, Jilin University, Changchun, 130026, P. R. China.
- Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun, 130021, P. R. China.
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6
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Xiao T, Dai Z, Viswanathan H, Hakala A, Cather M, Jia W, Zhang Y, McPherson B. Arsenic mobilization in shallow aquifers due to CO 2 and brine intrusion from storage reservoirs. Sci Rep 2017; 7:2763. [PMID: 28584255 PMCID: PMC5459901 DOI: 10.1038/s41598-017-02849-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 04/18/2017] [Indexed: 11/09/2022] Open
Abstract
We developed an integrated framework of combined batch experiments and reactive transport simulations to quantify water-rock-CO2 interactions and arsenic (As) mobilization responses to CO2 and/or saline water leakage into USDWs. Experimental and simulation results suggest that when CO2 is introduced, pH drops immediately that initiates release of As from clay minerals. Calcite dissolution can increase pH slightly and cause As re-adsorption. Thus, the mineralogy of the USDW is ultimately a determining factor of arsenic fate and transport. Salient results suggest that: (1) As desorption/adsorption from/onto clay minerals is the major reaction controlling its mobilization, and clay minerals could mitigate As mobilization with surface complexation reactions; (2) dissolution of available calcite plays a critical role in buffering pH; (3) high salinity in general hinders As release from minerals; and (4) the magnitude and quantitative uncertainty of As mobilization are predicated on the values of reaction rates and surface area of calcite, adsorption surface areas and equilibrium constants of clay minerals, and cation exchange capacity. Results of this study are intended to improve ability to quantify risks associated with potential leakage of reservoir fluids into shallow aquifers, in particular the possible environmental impacts of As mobilization at carbon sequestration sites.
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Affiliation(s)
- Ting Xiao
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, New Mexico, 87545, USA.,Department of Civil and Environmental Engineering, University of Utah, Salt Lake City, UT, 84112, USA.,Energy and Geoscience Institute, University of Utah, Salt Lake City, UT, 84108, USA
| | - Zhenxue Dai
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, New Mexico, 87545, USA. .,College of Construction Engineering, Jilin University, Changchun, 130026, China. .,Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun, 130021, China.
| | - Hari Viswanathan
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, New Mexico, 87545, USA
| | - Alexandra Hakala
- U.S. Department of Energy, National Energy and Technology Laboratory, Pittsburgh, PA, 10940, USA
| | - Martha Cather
- Petroleum Recovery Research Center, New Mexico Institute of Mining and Technology, Socorro, NM, 87801, USA
| | - Wei Jia
- Department of Civil and Environmental Engineering, University of Utah, Salt Lake City, UT, 84112, USA.,Energy and Geoscience Institute, University of Utah, Salt Lake City, UT, 84108, USA
| | - Yongchao Zhang
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, New Mexico, 87545, USA.,College of Geosciences, China University of Petroleum, Beijing, 102249, China
| | - Brian McPherson
- Department of Civil and Environmental Engineering, University of Utah, Salt Lake City, UT, 84112, USA.,Energy and Geoscience Institute, University of Utah, Salt Lake City, UT, 84108, USA
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7
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Divergence of stable isotopes in tap water across China. Sci Rep 2017; 7:43653. [PMID: 28252670 PMCID: PMC5333636 DOI: 10.1038/srep43653] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 01/25/2017] [Indexed: 12/03/2022] Open
Abstract
Stable isotopes in water (e.g., δ2H and δ18O) are important indicators of hydrological and ecological patterns and processes. Tap water can reflect integrated features of regional hydrological processes and human activities. China is a large country with significant meteorological and geographical variations. This report presents the first national-scale survey of Stable Isotopes in Tap Water (SITW) across China. 780 tap water samples have been collected from 95 cities across China from December 2014 to December 2015. (1) Results yielded the Tap Water Line in China is δ2H = 7.72 δ18O + 6.57 (r2 = 0.95). (2) SITW spatial distribution presents typical “continental effect”. (3) SITW seasonal variations indicate clearly regional patterns but no trends at the national level. (4) SITW can be correlated in some parts with geographic or meteorological factors. This work presents the first SITW map in China, which sets up a benchmark for further stable isotopes research across China. This is a critical step toward monitoring and investigating water resources in climate-sensitive regions, so the human-hydrological system. These findings could be used in the future to establish water management strategies at a national or regional scale.
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8
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Probabilistic Assessment of Above Zone Pressure Predictions at a Geologic Carbon Storage Site. Sci Rep 2016; 6:39536. [PMID: 27996043 PMCID: PMC5172198 DOI: 10.1038/srep39536] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 11/24/2016] [Indexed: 12/03/2022] Open
Abstract
Carbon dioxide (CO2) storage into geological formations is regarded as an important mitigation strategy for anthropogenic CO2 emissions to the atmosphere. This study first simulates the leakage of CO2 and brine from a storage reservoir through the caprock. Then, we estimate the resulting pressure changes at the zone overlying the caprock also known as Above Zone Monitoring Interval (AZMI). A data-driven approach of arbitrary Polynomial Chaos (aPC) Expansion is then used to quantify the uncertainty in the above zone pressure prediction based on the uncertainties in different geologic parameters. Finally, a global sensitivity analysis is performed with Sobol indices based on the aPC technique to determine the relative importance of different parameters on pressure prediction. The results indicate that there can be uncertainty in pressure prediction locally around the leakage zones. The degree of such uncertainty in prediction depends on the quality of site specific information available for analysis. The scientific results from this study provide substantial insight that there is a need for site-specific data for efficient predictions of risks associated with storage activities. The presented approach can provide a basis of optimized pressure based monitoring network design at carbon storage sites.
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9
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Dai Z, Viswanathan H, Middleton R, Pan F, Ampomah W, Yang C, Jia W, Xiao T, Lee SY, McPherson B, Balch R, Grigg R, White M. CO2 Accounting and Risk Analysis for CO2 Sequestration at Enhanced Oil Recovery Sites. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:7546-7554. [PMID: 27362472 DOI: 10.1021/acs.est.6b01744] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Using CO2 in enhanced oil recovery (CO2-EOR) is a promising technology for emissions management because CO2-EOR can dramatically reduce sequestration costs in the absence of emissions policies that include incentives for carbon capture and storage. This study develops a multiscale statistical framework to perform CO2 accounting and risk analysis in an EOR environment at the Farnsworth Unit (FWU), Texas. A set of geostatistical-based Monte Carlo simulations of CO2-oil/gas-water flow and transport in the Morrow formation are conducted for global sensitivity and statistical analysis of the major risk metrics: CO2/water injection/production rates, cumulative net CO2 storage, cumulative oil/gas productions, and CO2 breakthrough time. The median and confidence intervals are estimated for quantifying uncertainty ranges of the risk metrics. A response-surface-based economic model has been derived to calculate the CO2-EOR profitability for the FWU site with a current oil price, which suggests that approximately 31% of the 1000 realizations can be profitable. If government carbon-tax credits are available, or the oil price goes up or CO2 capture and operating expenses reduce, more realizations would be profitable. The results from this study provide valuable insights for understanding CO2 storage potential and the corresponding environmental and economic risks of commercial-scale CO2-sequestration in depleted reservoirs.
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Affiliation(s)
- Zhenxue Dai
- Earth and Environmental Sciences Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
| | - Hari Viswanathan
- Earth and Environmental Sciences Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
| | - Richard Middleton
- Earth and Environmental Sciences Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
| | - Feng Pan
- Energy and Geoscience Institute, The University of Utah , Salt Lake City, Utah 84108, United States
| | - William Ampomah
- Petroleum Recovery Research Center, New Mexico Tech , Socorro, New Mexico 87801, United States
| | - Changbing Yang
- Bureau of Economic Geology, The University of Texas at Austin , Austin, Texas 78713, United States
| | - Wei Jia
- Energy and Geoscience Institute, The University of Utah , Salt Lake City, Utah 84108, United States
| | - Ting Xiao
- Energy and Geoscience Institute, The University of Utah , Salt Lake City, Utah 84108, United States
| | - Si-Yong Lee
- Schlumberger Carbon Services , Cambridge, Massachusetts 02139, United States
| | - Brian McPherson
- Energy and Geoscience Institute, The University of Utah , Salt Lake City, Utah 84108, United States
| | - Robert Balch
- Petroleum Recovery Research Center, New Mexico Tech , Socorro, New Mexico 87801, United States
| | - Reid Grigg
- Petroleum Recovery Research Center, New Mexico Tech , Socorro, New Mexico 87801, United States
| | - Mark White
- Pacific Northwest National Laboratory , Richland, Washington 99354, United States
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10
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Islam A, Sun AY, Yang C. Reactive Transport Modeling of the Enhancement of Density-Driven CO2 Convective Mixing in Carbonate Aquifers and its Potential Implication on Geological Carbon Sequestration. Sci Rep 2016; 6:24768. [PMID: 27094448 PMCID: PMC4837360 DOI: 10.1038/srep24768] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 04/04/2016] [Indexed: 11/09/2022] Open
Abstract
We study the convection and mixing of CO2 in a brine aquifer, where the spread of dissolved CO2 is enhanced because of geochemical reactions with the host formations (calcite and dolomite), in addition to the extensively studied, buoyancy-driven mixing. The nonlinear convection is investigated under the assumptions of instantaneous chemical equilibrium, and that the dissipation of carbonate rocks solely depends on flow and transport and chemical speciation depends only on the equilibrium thermodynamics of the chemical system. The extent of convection is quantified in term of the CO2 saturation volume of the storage formation. Our results suggest that the density increase of resident species causes significant enhancement in CO2 dissolution, although no significant porosity and permeability alterations are observed. Early saturation of the reservoir can have negative impact on CO2 sequestration.
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Affiliation(s)
- Akand Islam
- Bureau of Economic Geology, The University of Texas at Austin, TX, USA
| | - Alexander Y Sun
- Bureau of Economic Geology, The University of Texas at Austin, TX, USA
| | - Changbing Yang
- Bureau of Economic Geology, The University of Texas at Austin, TX, USA
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11
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Improved estimation of hydraulic conductivity by combining stochastically simulated hydrofacies with geophysical data. Sci Rep 2016; 6:22224. [PMID: 26927886 PMCID: PMC4772070 DOI: 10.1038/srep22224] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 02/03/2016] [Indexed: 11/17/2022] Open
Abstract
Hydraulic conductivity is a major parameter affecting the output accuracy of groundwater flow and transport models. The most commonly used semi-empirical formula for estimating conductivity is Kozeny-Carman equation. However, this method alone does not work well with heterogeneous strata. Two important parameters, grain size and porosity, often show spatial variations at different scales. This study proposes a method for estimating conductivity distributions by combining a stochastic hydrofacies model with geophysical methods. The Markov chain model with transition probability matrix was adopted to re-construct structures of hydrofacies for deriving spatial deposit information. The geophysical and hydro-chemical data were used to estimate the porosity distribution through the Archie’s law. Results show that the stochastic simulated hydrofacies model reflects the sedimentary features with an average model accuracy of 78% in comparison with borehole log data in the Chaobai alluvial fan. The estimated conductivity is reasonable and of the same order of magnitude of the outcomes of the pumping tests. The conductivity distribution is consistent with the sedimentary distributions. This study provides more reliable spatial distributions of the hydraulic parameters for further numerical modeling.
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12
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A quantitative analysis of hydraulic interaction processes in stream-aquifer systems. Sci Rep 2016; 6:19876. [PMID: 26818442 PMCID: PMC4730216 DOI: 10.1038/srep19876] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 12/14/2015] [Indexed: 11/10/2022] Open
Abstract
The hydraulic relationship between the stream and aquifer can be altered from hydraulic connection to disconnection when the pumping rate exceeds the maximum seepage flux of the streambed. This study proposes to quantitatively analyze the physical processes of stream-aquifer systems from connection to disconnection. A free water table equation is adopted to clarify under what conditions a stream starts to separate hydraulically from an aquifer. Both the theoretical analysis and laboratory tests have demonstrated that the hydraulic connectedness of the stream-aquifer system can reach a critical disconnection state when the horizontal hydraulic gradient at the free water surface is equal to zero and the vertical is equal to 1. A boundary-value problem for movement of the critical point of disconnection is established for an analytical solution of the inverted water table movement beneath the stream. The result indicates that the maximum distance or thickness of the inverted water table is equal to the water depth in the stream, and at a steady state of disconnection, the maximum hydraulic gradient at the streambed center is 2. This study helps us to understand the hydraulic phenomena of water flow near streams and accurately assess surface water and groundwater resources.
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13
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Shao H, Qafoku NP, Lawter AR, Bowden ME, Brown CF. Coupled Geochemical Impacts of Leaking CO2 and Contaminants from Subsurface Storage Reservoirs on Groundwater Quality. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:8202-8209. [PMID: 26039150 DOI: 10.1021/acs.est.5b01004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The leakage of CO2 and the concomitant brine from deep storage reservoirs to overlying groundwater aquifers is considered one of the major potential risks associated with geologic CO2 sequestration (GCS). In this work both batch and column experiments were conducted to determine the fate of trace metals in groundwater in the scenarios of CO2 and metal-contaminated brine leakage. The sediments for this study were from an unconsolidated sand and gravel aquifer in Kansas, containing 0-4 wt % carbonates. Cd (114 μg/L) and As (40 μg/L) were spiked into the reaction system to represent potential contaminants from the reservoir brine. Through this research we demonstrated that Cd and As were adsorbed on the sediments, in spite of the lowered pH due to CO2 dissolution in the groundwater. Cd concentrations in the effluent were below the Cd MCL, even for sediments without detectable carbonate to buffer the pH. Arsenic concentrations in the effluent were also significantly lower than the influent concentration, suggesting that the sediments tested have the capacity to mitigate the coupled adverse effects of CO2 leakage and brine intrusion. The mitigation capacity of sediment is a function of its geochemical properties (e.g., the presence of carbonate minerals, adsorbed As, and phosphate).
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Affiliation(s)
- Hongbo Shao
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Nikolla P Qafoku
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Amanda R Lawter
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Mark E Bowden
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Christopher F Brown
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
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14
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Yang C, Hovorka SD, Delgado-Alonso J, Mickler PJ, Treviño RH, Phillips S. Field demonstration of CO2 leakage detection in potable aquifers with a pulselike CO2-release test. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:14031-14040. [PMID: 25383791 DOI: 10.1021/es5044003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
This study presents two field pulselike CO2-release tests to demonstrate CO2 leakage detection in a shallow aquifer by monitoring groundwater pH, alkalinity, and dissolved inorganic carbon (DIC) using the periodic groundwater sampling method and a fiber-optic CO2 sensor for real-time in situ monitoring of dissolved CO2 in groundwater. Measurements of groundwater pH, alkalinity, DIC, and dissolved CO2 clearly deviated from their background values, showing responses to CO2 leakage. Dissolved CO2 observed in the tests was highly sensitive in comparison to groundwater pH, DIC, and alkalinity. Comparison of the pulselike CO2-release tests to other field tests suggests that pulselike CO2-release tests can provide reliable assessment of geochemical parameters indicative of CO2 leakage. Measurements by the fiber-optic CO2 sensor, showing obvious leakage signals, demonstrated the potential of real-time in situ monitoring of dissolved CO2 for leakage detection at a geologic carbon sequestration (GCS) site. Results of a two-dimensional reactive transport model reproduced the geochemical measurements and confirmed that the decrease in groundwater pH and the increases in DIC and dissolved CO2 observed in the pulselike CO2-release tests were caused by dissolution of CO2 whereas alkalinity was likely affected by carbonate dissolution.
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Affiliation(s)
- Changbing Yang
- Bureau of Economic Geology, The University of Texas at Austin , Austin, Texas 78759, United States
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15
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