Kinetic rate of iron release during artificial CO{sub 2} injection in a shallow aquifer: preliminary results

Energy Technology Data Exchange (ETDEWEB)

Rillard, J. [Earth Sciences Department UMR CNRS 5276 University of Lyon 1, Villeurbanne (France); INERIS French National Institut of Environmental and Industrial Risk Survey, Underground Risk Division,, Verneuil en Hallate (France); Gombert, P.; Toulhoat, P. [INERIS French National Institut of Environmental and Industrial Risk Survey, Underground Risk Division,, Verneuil en Hallate (France); Zuddas, P. [Earth Sciences Department UMR CNRS 5276 University of Lyon 1, Villeurbanne (France); University Pierre and Marie Curie Paris-Sorbonne, ISTEP, Paris (France)

2013-07-01

We performed an injection of CO{sub 2}-saturated water in a shallow aquifer following a 'push-pull' test protocol. A specific protocol was designed to measure in situ fluid pH and redox potential with careful sampling. We found increases of dissolved calcium, magnesium, alkalinity, iron and manganese, and other trace elements. Concentrations of Fe resulting from reactivity were estimated using measured concentrations of Fe corrected by a calculated fluid dynamics coefficient. Thermodynamic equilibrium calculations suggested that ferri-hydrite Fe(OH){sub 3} dissolution is the main source of iron release. The kinetic rate of Fe(OH){sub 3} dissolution estimated by a surface protonation model indicates that the reaction order is two. Since laboratory experimental results show a reaction order of zero, we propose that the mechanism of ferri-hydrite dissolution proceeds by a more complex mechanism under natural conditions. (authors)

Natural and industrial analogues for release of CO2 from storagereservoirs: Identification of features, events, and processes and lessonslearned

Energy Technology Data Exchange (ETDEWEB)

Lewicki, Jennifer L.; Birkholzer, Jens; Tsang, Chin-Fu

2006-03-03

The injection and storage of anthropogenic CO{sub 2} in deep geologic formations is a potentially feasible strategy to reduce CO{sub 2} emissions and atmospheric concentrations. While the purpose of geologic carbon storage is to trap CO{sub 2} underground, CO{sub 2} could migrate away from the storage site into the shallow subsurface and atmosphere if permeable pathways such as well bores or faults are present. Large-magnitude releases of CO{sub 2} have occurred naturally from geologic reservoirs in numerous volcanic, geothermal, and sedimentary basin settings. Carbon dioxide and natural gas have also been released from geologic CO{sub 2} reservoirs and natural gas storage facilities, respectively, due to influences such as well defects and injection/withdrawal processes. These systems serve as natural and industrial analogues for the potential release of CO{sub 2} from geologic storage reservoirs and provide important information about the key features, events, and processes (FEPs) that are associated with releases, as well as the health, safety, and environmental consequences of releases and mitigation efforts that can be applied. We describe a range of natural releases of CO{sub 2} and industrial releases of CO{sub 2} and natural gas in the context of these characteristics. Based on this analysis, several key conclusions can be drawn, and lessons can be learned for geologic carbon storage. First, CO{sub 2} can both accumulate beneath, and be released from, primary and secondary reservoirs with capping units located at a wide range of depths. Both primary and secondary reservoir entrapments for CO{sub 2} should therefore be well characterized at storage sites. Second, many natural releases of CO{sub 2} have been correlated with a specific event that triggered the release, such as magmatic fluid intrusion or seismic activity. The potential for processes that could cause geomechanical damage to sealing cap rocks and trigger the release of CO{sub 2} from a storage

Enhanced CO2 uptake at a shallow Arctic Ocean seep field overwhelms the positive warming potential of emitted methane.

Science.gov (United States)

Pohlman, John W; Greinert, Jens; Ruppel, Carolyn; Silyakova, Anna; Vielstädte, Lisa; Casso, Michael; Mienert, Jürgen; Bünz, Stefan

2017-05-23

Continued warming of the Arctic Ocean in coming decades is projected to trigger the release of teragrams (1 Tg = 10 6 tons) of methane from thawing subsea permafrost on shallow continental shelves and dissociation of methane hydrate on upper continental slopes. On the shallow shelves (shallow ebullitive methane seep field on the Svalbard margin reveal atmospheric CO 2 uptake rates (-33,300 ± 7,900 μmol m -2 ⋅d -1 ) twice that of surrounding waters and ∼1,900 times greater than the diffusive sea-air methane efflux (17.3 ± 4.8 μmol m -2 ⋅d -1 ). The negative radiative forcing expected from this CO 2 uptake is up to 231 times greater than the positive radiative forcing from the methane emissions. Surface water characteristics (e.g., high dissolved oxygen, high pH, and enrichment of 13 C in CO 2 ) indicate that upwelling of cold, nutrient-rich water from near the seafloor accompanies methane emissions and stimulates CO 2 consumption by photosynthesizing phytoplankton. These findings challenge the widely held perception that areas characterized by shallow-water methane seeps and/or strongly elevated sea-air methane flux always increase the global atmospheric greenhouse gas burden.

Capabilities of seismic and georadar 2D/3D imaging of shallow subsurface of transport route using the Seismobile system

Science.gov (United States)

Pilecki, Zenon; Isakow, Zbigniew; Czarny, Rafał; Pilecka, Elżbieta; Harba, Paulina; Barnaś, Maciej

2017-08-01

In this work, the capabilities of the Seismobile system for shallow subsurface imaging of transport routes, such as roads, railways, and airport runways, in different geological conditions were presented. The Seismobile system combines the advantages of seismic profiling using landstreamer and georadar (GPR) profiling. It consists of up to four seismic measuring lines and carriage with a suspended GPR antenna. Shallow subsurface recognition may be achieved to a maximum width of 10.5 m for a distance of 3.5 m between the measurement lines. GPR measurement is performed in the axis of the construction. Seismobile allows the measurement time, labour and costs to be reduced due to easy technique of its installation, remote data transmission from geophones to accompanying measuring modules, automated location of the system based on GPS and a highly automated method of seismic wave excitation. In this paper, the results of field tests carried out in different geological conditions were presented. The methodologies of acquisition, processing and interpretation of seismic and GPR measurements were broadly described. Seismograms and its spectrum registered by Seismobile system were compared to the ones registered by Geode seismograph of Geometrix. Seismic data processing and interpretation software allows for the obtaining of 2D/3D models of P- and S-wave velocities. Combined seismic and GPR results achieved sufficient imaging of shallow subsurface to a depth of over a dozen metres. The obtained geophysical information correlated with geological information from the boreholes with good quality. The results of performed tests proved the efficiency of the Seismobile system in seismic and GPR imaging of a shallow subsurface of transport routes under compound conditions.

Composition and structure of the shallow subsurface of Ceres revealed by crater morphology

Science.gov (United States)

Bland, Michael T.; Carol A. Raymond,; Schenk, Paul M.; Roger R. Fu,; Thomas Kneisl,; Hendrick Pasckert, Jan; Hiesinger, Harald; Frank Preusker,; Ryan S. Park,; Simone Marchi,; Scott King,; Castillo-Rogez, Julie C.; Christopher T. Russell,

2016-01-01

Before NASA’s Dawn mission, the dwarf planet Ceres was widely believed to contain a substantial ice-rich layer below its rocky surface. The existence of such a layer has significant implications for Ceres’s formation, evolution, and astrobiological potential. Ceres is warmer than icy worlds in the outer Solar System and, if its shallow subsurface is ice-rich, large impact craters are expected to be erased by viscous flow on short geologic timescales. Here we use digital terrain models derived from Dawn Framing Camera images to show that most of Ceres’s largest craters are several kilometres deep, and are therefore inconsistent with the existence of an ice-rich subsurface. We further show from numerical simulations that the absence of viscous relaxation over billion-year timescales implies a subsurface viscosity that is at least one thousand times greater than that of pure water ice. We conclude that Ceres’s shallow subsurface is no more than 30% to 40% ice by volume, with a mixture of rock, salts and/or clathrates accounting for the other 60% to 70%. However, several anomalously shallow craters are consistent with limited viscous relaxation and may indicate spatial variations in subsurface ice content.

Heterogeneity-enhanced gas phase formation in shallow aquifers during leakage of CO2-saturated water from geologic sequestration sites

Science.gov (United States)

Plampin, Michael R.; Lassen, Rune N.; Sakaki, Toshihiro; Porter, Mark L.; Pawar, Rajesh J.; Jensen, Karsten H.; Illangasekare, Tissa H.

2014-12-01

A primary concern for geologic carbon storage is the potential for leakage of stored carbon dioxide (CO2) into the shallow subsurface where it could degrade the quality of groundwater and surface water. In order to predict and mitigate the potentially negative impacts of CO2 leakage, it is important to understand the physical processes that CO2 will undergo as it moves through naturally heterogeneous porous media formations. Previous studies have shown that heterogeneity can enhance the evolution of gas phase CO2 in some cases, but the conditions under which this occurs have not yet been quantitatively defined, nor tested through laboratory experiments. This study quantitatively investigates the effects of geologic heterogeneity on the process of gas phase CO2 evolution in shallow aquifers through an extensive set of experiments conducted in a column that was packed with layers of various test sands. Soil moisture sensors were utilized to observe the formation of gas phase near the porous media interfaces. Results indicate that the conditions under which heterogeneity controls gas phase evolution can be successfully predicted through analysis of simple parameters, including the dissolved CO2 concentration in the flowing water, the distance between the heterogeneity and the leakage location, and some fundamental properties of the porous media. Results also show that interfaces where a less permeable material overlies a more permeable material affect gas phase evolution more significantly than interfaces with the opposite layering.

Preliminary Study of Favourable Formations for CO2 Subsurface Storage in Spain

International Nuclear Information System (INIS)

Zapatero, M. A.; Reyes, J. L.; Martinez, R.; Suarez, I.; Arenillas, A.; Perucha, M. A.

2009-01-01

This report is a synthesis of the possibilities of CO 2 storage in the Spanish subsurface. Compilation and analysis of geological information has been carried out, looking at surface and subsurface, in order to make a pre-selection of potential favourable units for CO 2 storage, taking in account that each of this storages needs a confining formation to seal the storage. Before the storage selection, a general description of the great geological units of the Iberian Peninsula is done. Afterwards, borehole logging from petroleum exploration is analysed in these units, formations and areas of interest. The aim is to finally obtain a description of selected units and their possibilities of CO 2 storage. (Author) 17 refs

Large temporal scale and capacity subsurface bulk energy storage with CO2

Science.gov (United States)

Saar, M. O.; Fleming, M. R.; Adams, B. M.; Ogland-Hand, J.; Nelson, E. S.; Randolph, J.; Sioshansi, R.; Kuehn, T. H.; Buscheck, T. A.; Bielicki, J. M.

2017-12-01

Decarbonizing energy systems by increasing the penetration of variable renewable energy (VRE) technologies requires efficient and short- to long-term energy storage. Very large amounts of energy can be stored in the subsurface as heat and/or pressure energy in order to provide both short- and long-term (seasonal) storage, depending on the implementation. This energy storage approach can be quite efficient, especially where geothermal energy is naturally added to the system. Here, we present subsurface heat and/or pressure energy storage with supercritical carbon dioxide (CO2) and discuss the system's efficiency, deployment options, as well as its advantages and disadvantages, compared to several other energy storage options. CO2-based subsurface bulk energy storage has the potential to be particularly efficient and large-scale, both temporally (i.e., seasonal) and spatially. The latter refers to the amount of energy that can be stored underground, using CO2, at a geologically conducive location, potentially enabling storing excess power from a substantial portion of the power grid. The implication is that it would be possible to employ centralized energy storage for (a substantial part of) the power grid, where the geology enables CO2-based bulk subsurface energy storage, whereas the VRE technologies (solar, wind) are located on that same power grid, where (solar, wind) conditions are ideal. However, this may require reinforcing the power grid's transmission lines in certain parts of the grid to enable high-load power transmission from/to a few locations.

Liquid Water in the Extremely Shallow Martian Subsurface

Science.gov (United States)

Pavlov, A.; Shivak, J. N.

2012-01-01

Availability of liquid water is one of the major constraints for the potential Martian biosphere. Although liquid water is unstable on the surface of Mars due to low atmospheric pressures, it has been suggested that liquid films of water could be present in the Martian soil. Here we explored a possibility of the liquid water formation in the extremely shallow (1-3 cm) subsurface layer under low atmospheric pressures (0.1-10 mbar) and low ("Martian") surface temperatures (approx.-50 C-0 C). We used a new Goddard Martian simulation chamber to demonstrate that even in the clean frozen soil with temperatures as low as -25C the amount of mobile water can reach several percents. We also showed that during brief periods of simulated daylight warming the shallow subsurface ice sublimates, the water vapor diffuses through porous surface layer of soil temporarily producing supersaturated conditions in the soil, which leads to the formation of additional liquid water. Our results suggest that despite cold temperatures and low atmospheric pressures, Martian soil just several cm below the surface can be habitable.

Subsurface plasma in beam of continuous CO2-laser

Science.gov (United States)

Danytsikov, Y. V.; Dymshakov, V. A.; Lebedev, F. V.; Pismennyy, V. D.; Ryazanov, A. V.

1986-03-01

Experiments performed at the Institute of Atomic Energy established the conditions for formation of subsurface plasma in substances by laser radiation and its characteristics. A quasi-continuous CO2 laser emitting square pulses of 0.1 to 1.0 ms duration and 1 to 10 kW power as well as a continuous CO2 laser served as radiation sources. Radiation was focused on spots 0.1 to 0.5 mm in diameter and maintained at levels ensuring constant power density during the interaction time, while the temperature of the target surface was measured continuously. Metals, graphite and dielectric materials were tested with laser action taking place in air N2 + O2 mixtures, Ar or He atmosphere under pressures of 0.01 to 1.0 atm. Data on radiation intensity thresholds for evaporation and plasma formation were obtained. On the basis of these thresholds, combined with data on energy balance and the temperature profile in plasma layers, a universal state diagram was constructed for subsurface plasma with nonquantified surface temperature and radiation intensity coordinates.

Air–Sea CO2 Gas Transfer Velocity in a Shallow Estuary

DEFF Research Database (Denmark)

Mørk, Eva Thorborg; Sørensen, Lise Lotte; Jensen, Bjarne

2014-01-01

The air–sea transfer velocity of CO2(kCO2) was investigated in a shallow estuary in March to July 2012, using eddy-covariance measurements of CO2 fluxes and measured air–sea CO2 partial-pressure differences. A data evaluation method that eliminates data by nine rejection criteria in order......, the transfer velocity in the shallow water estuary was lower than in other coastal waters, possibly a symptom of low tidal amplitude leading to low intensity water turbulence. High transfer velocities were recorded above wind speeds of 5 m s−1 , believed to be caused by early-breaking waves and the large fetch...... (6.5 km) of the estuary. These findings indicate that turbulence in both air and water influences the transfer velocity....

Temporal change in shallow subsurface P- and S-wave velocities and S-wave anisotropy inferred from coda wave interferometry

Science.gov (United States)

Yamamoto, M.; Nishida, K.; Takeda, T.

2012-12-01

Recent progresses in theoretical and observational researches on seismic interferometry reveal the possibility to detect subtle change in subsurface seismic structure. This high sensitivity of seismic interferometry to the medium properties may thus one of the most important ways to directly observe the time-lapse behavior of shallow crustal structure. Here, using the coda wave interferometry, we show the co-seismic and post-seismic changes in P- and S-wave velocities and S-wave anisotropy associated with the 2011 off the Pacific coast of Tohoku earthquake (M9.0). In this study, we use the acceleration data recorded at KiK-net stations operated by NIED, Japan. Each KiK-net station has a borehole whose typical depth is about 100m, and two three-component accelerometers are installed at the top and bottom of the borehole. To estimate the shallow subsurface P- and S-wave velocities and S-wave anisotropy between two sensors and their temporal change, we select about 1000 earthquakes that occurred between 2004 and 2012, and extract body waves propagating between borehole sensors by computing the cross-correlation functions (CCFs) of 3 x 3 component pairs. We use frequency bands of 2-4, 4-8, 8-16 Hz in our analysis. Each averaged CCF shows clear wave packets traveling between borehole sensors, and their travel times are almost consistent with those of P- and S-waves calculated from the borehole log data. Until the occurrence of the 2011 Tohoku earthquake, the estimated travel time at each station is rather stable with time except for weak seasonal/annual variation. On the other hand, the 2011 Tohoku earthquake and its aftershocks cause sudden decrease in the S-wave velocity at most of the KiK-net stations in eastern Japan. The typical value of S-wave velocity changes, which are measured by the time-stretching method, is about 5-15%. After this co-seismic change, the S-wave velocity gradually recovers with time, and the recovery continues for over one year following the

High net CO2 and CH4 release at a eutrophic shallow lake on a formerly drained fen

Science.gov (United States)

Franz, Daniela; Koebsch, Franziska; Larmanou, Eric; Augustin, Jürgen; Sachs, Torsten

2016-05-01

Drained peatlands often act as carbon dioxide (CO2) hotspots. Raising the groundwater table is expected to reduce their CO2 contribution to the atmosphere and revitalise their function as carbon (C) sink in the long term. Without strict water management rewetting often results in partial flooding and the formation of spatially heterogeneous, nutrient-rich shallow lakes. Uncertainties remain as to when the intended effect of rewetting is achieved, as this specific ecosystem type has hardly been investigated in terms of greenhouse gas (GHG) exchange. In most cases of rewetting, methane (CH4) emissions increase under anoxic conditions due to a higher water table and in terms of global warming potential (GWP) outperform the shift towards CO2 uptake, at least in the short term.Based on eddy covariance measurements we studied the ecosystem-atmosphere exchange of CH4 and CO2 at a shallow lake situated on a former fen grassland in northeastern Germany. The lake evolved shortly after flooding, 9 years previous to our investigation period. The ecosystem consists of two main surface types: open water (inhabited by submerged and floating vegetation) and emergent vegetation (particularly including the eulittoral zone of the lake, dominated by Typha latifolia). To determine the individual contribution of the two main surface types to the net CO2 and CH4 exchange of the whole lake ecosystem, we combined footprint analysis with CH4 modelling and net ecosystem exchange partitioning.The CH4 and CO2 dynamics were strikingly different between open water and emergent vegetation. Net CH4 emissions from the open water area were around 4-fold higher than from emergent vegetation stands, accounting for 53 and 13 g CH4 m-2 a-1 respectively. In addition, both surface types were net CO2 sources with 158 and 750 g CO2 m-2 a-1 respectively. Unusual meteorological conditions in terms of a warm and dry summer and a mild winter might have facilitated high respiration rates. In sum, even after 9

Sustainable intensive thermal use of the shallow subsurface-a critical view on the status quo.

Science.gov (United States)

Vienken, T; Schelenz, S; Rink, K; Dietrich, P

2015-01-01

Thermal use of the shallow subsurface for heat generation, cooling, and thermal energy storage is increasingly gaining importance in reconsideration of future energy supplies. Shallow geothermal energy use is often promoted as being of little or no costs during operation, while simultaneously being environmentally friendly. Hence, the number of installed systems has rapidly risen over the last few decades, especially among newly built houses. While the carbon dioxide reduction potential of this method remains undoubted, concerns about sustainability and potential negative effects on the soil and groundwater due to an intensified use have been raised-even as far back as 25 years ago. Nevertheless, consistent regulation and management schemes for the intensified thermal use of the shallow subsurface are still missing-mainly due to a lack of system understanding and process knowledge. In the meantime, large geothermal applications, for example, residential neighborhoods that are entirely dependent up on shallow geothermal energy use or low enthalpy aquifer heat storage, have been developed throughout Europe. Potential negative effects on the soil and groundwater due to an intensive thermal use of the shallow subsurface as well as the extent of potential system interaction still remain unknown. © 2014, National Ground Water Association.

Yield response and economics of shallow subsurface drip irrigation systems

Science.gov (United States)

Field tests were conducted using shallow subsurface drip irrigation (S3DI) on cotton (Gossypium hirsutum, L.), corn (Zea mays, L.), and peanut (Arachis hypogeae, L.) in rotation to investigate yield potential and economic sustainability of this irrigation system technique over a six year period. Dri...

Monitoring a pilot CO2 injection experiment in a shallow aquifer using 3D cross-well electrical resistance tomography

Science.gov (United States)

Yang, X.; Lassen, R. N.; Looms, M. C.; Jensen, K. H.

2014-12-01

Three dimensional electrical resistance tomography (ERT) was used to monitor a pilot CO2 injection experiment at Vrøgum, Denmark. The purpose was to evaluate the effectiveness of the ERT method for monitoring the two opposing effects from gas-phase and dissolved CO2 in a shallow unconfined siliciclastic aquifer. Dissolved CO2 increases water electrical conductivity (EC) while gas phase CO2 reduce EC. We injected 45kg of CO2 into a shallow aquifer for 48 hours. ERT data were collected for 50 hours following CO2 injection. Four ERT monitoring boreholes were installed on a 5m by 5m square grid and each borehole had 24 electrodes at 0.5 m electrode spacing at depths from 1.5 m to 13 m. ERT data were inverted using a difference inversion algorithm for bulk EC. 3D ERT successfully detected the CO2 plume distribution and growth in the shallow aquifer. We found that the changes of bulk EC were dominantly positive following CO2 injection, indicating that the effect of dissolved CO2 overwhelmed that of gas phase CO2. The pre-injection baseline resistivity model clearly showed a three-layer structure of the site. The electrically more conductive glacial sand layer in the northeast region are likely more permeable than the overburden and underburden and CO2 plumes were actually confined in this layer. Temporal bulk EC increase from ERT agreed well with water EC and cross-borehole ground penetrating radar data. ERT monitoring offers a competitive advantage over water sampling and GPR methods because it provides 3D high-resolution temporal tomographic images of CO2 distribution and it can also be automated for unattended operation. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344. Lawrence Livermore National Security, LLC. LLNL IM release#: LLNL-PROC-657944.

Recovery Act: Web-based CO{sub 2} Subsurface Modeling

Energy Technology Data Exchange (ETDEWEB)

Paolini, Christopher; Castillo, Jose

2012-11-30

The Web-based CO{sub 2} Subsurface Modeling project focused primarily on extending an existing text-only, command-line driven, isothermal and isobaric, geochemical reaction-transport simulation code, developed and donated by Sienna Geodynamics, into an easier-to-use Web-based application for simulating long-term storage of CO{sub 2} in geologic reservoirs. The Web-based interface developed through this project, publically accessible via URL http://symc.sdsu.edu/, enables rapid prototyping of CO{sub 2} injection scenarios and allows students without advanced knowledge of geochemistry to setup a typical sequestration scenario, invoke a simulation, analyze results, and then vary one or more problem parameters and quickly re-run a simulation to answer what-if questions. symc.sdsu.edu has 2x12 core AMD Opteron™ 6174 2.20GHz processors and 16GB RAM. The Web-based application was used to develop a new computational science course at San Diego State University, COMP 670: Numerical Simulation of CO{sub 2} Sequestration, which was taught during the fall semester of 2012. The purpose of the class was to introduce graduate students to Carbon Capture, Use and Storage (CCUS) through numerical modeling and simulation, and to teach students how to interpret simulation results to make predictions about long-term CO{sub 2} storage capacity in deep brine reservoirs. In addition to the training and education component of the project, significant software development efforts took place. Two computational science doctoral and one geological science masters student, under the direction of the PIs, extended the original code developed by Sienna Geodynamics, named Sym.8. New capabilities were added to Sym.8 to simulate non-isothermal and non-isobaric flows of charged aqueous solutes in porous media, in addition to incorporating HPC support into the code for execution on many-core XSEDE clusters. A successful outcome of this project was the funding and training of three new computational

Field experiments with subsurface releases of oil and and dyed water

International Nuclear Information System (INIS)

Rye, H.; Brandvik, P.J.; Strom, T.

1998-01-01

A field experiment with a subsurface release of oil and air was carried out in June 1996 close to the Frigg Field in the North Sea area. One of the purposes of this sea trial was to increase the knowledge concerning the behaviour of the oil and gas during a subsurface blowout. This was done by releasing oil and air at 106 meters depth with a realistic gas oil ratio (GOR=67) and release velocity of the oil. In addition to the oil release, several releases with dyed water and gas (GOR=7 - 65) were performed. Important and unique data were collected during these subsurface releases. In particular, the experiments with the dyed water releases combined with air turned out to be an efficient way of obtaining field data for the behaviour of subsurface plumes. The main conclusions from analysis for the data collected are: the field methodology used to study blowout releases in the field appears to be appropriate. The use of dyed water to determine the performance of the subsurface plume proved out to be an efficient way to obtain reliable and useful data. The behaviour of the subsurface plume is very sensitive to gas flow rates. For low gas flow rates, the plume did not reach the sea surface at all due to the presence of stratification in the ambient water. Some discrepancies were found between a numerical model for subsurface releases and field results. These discrepancies are pointed out, and recommendations for possible model improvements are given. (author)

CO2 exsolution - challenges and opportunities in subsurface flow management

Science.gov (United States)

Zuo, Lin; Benson, Sally

2014-05-01

In geological carbon sequestration, a large amount of injected CO2 will dissolve in brine over time. Exsolution occurs when pore pressures decline and CO2 solubility in brine decreases, resulting in the formation of a separate CO2 phase. This scenario occurs in storage reservoirs by upward migration of carbonated brine, through faults, leaking boreholes or even seals, driven by a reverse pressure gradient from CO2 injection or ground water extraction. In this way, dissolved CO2 could migrate out of storage reservoirs and form a gas phase at shallower depths. This paper summarizes the results of a 4-year study regarding the implications of exsolution on storage security, including core-flood experiments, micromodel studies, and numerical simulation. Micromodel studies have shown that, different from an injected CO2 phase, where the gas remains interconnected, exsolved CO2 nucleates in various locations of a porous medium, forms disconnected bubbles and propagates by a repeated process of bubble expansion and snap-off [Zuo et al., 2013]. A good correlation between bubble size distribution and pore size distribution is observed, indicating that geometry of the pore space plays an important role in controlling the mobility of brine and exsolved CO2. Core-scale experiments demonstrate that as the exsolved gas saturation increases, the water relative permeability drops significantly and is disproportionately reduced compared to drainage relative permeability [Zuo et al., 2012]. The CO2 relative permeability remains very low, 10-5~10-3, even when the exsolved CO2 saturation increases to over 40%. Furthermore, during imbibition with CO2 saturated brines, CO2 remains trapped even under relatively high capillary numbers (uv/σ~10-6) [Zuo et al., submitted]. The water relative permeability at the imbibition endpoint is 1/3~1/2 of that with carbonated water displacing injected CO2. Based on the experimental evidence, CO2 exsolution does not appear to create significant risks

Negative CO2 emissions via subsurface mineral carbonation in fractured peridotite

Science.gov (United States)

Kelemen, P. B.; Matter, J.

2014-12-01

Uptake of CO2 from surface water via mineral carbonation in peridotite can be engineered to achieve negative CO2 emissions. Reaction with peridotite, e.g., CO2 + olivine (A), serpentine (B) and brucite (C), forms inert, non-toxic, solid carbonates such as magnesite. Experimental studies show that A can be 80% complete in a few hours with 30 micron powders and elevated P(CO2) [1,2,3]. B is slower, but in natural systems the rate of B+C is significant [4]. Methods for capture of dilute CO2 via mineral carbonation [4,5,6,7] are not well known, though CO2 storage via mineral carbonation has been discussed for decades [8,9]. Where crushed peridotite is available, as in mine tailings, increased air or water flow could enhance CO2 uptake at a reasonable cost [4,5]. Here we focus on enhancing subsurface CO2 uptake from surface water flowing in fractured peridotite, in systems driven by thermal convection such as geothermal power plants. Return of depleted water to the surface would draw down CO2 from the air [6,7]. CO2 uptake from water, rate limited by flow in input and output wells, could exceed 1000 tons CO2/yr [7]. If well costs minus power sales were 0.1M to 1M and each system lasts 10 years this costs oil industry. Uptake of 1 Gt CO2/yr at 1000 t/well/yr requires 1M wells, comparable to the number of producing oil and gas wells in the USA. Subsurface CO2 uptake could first be applied in coastal, sub-seafloor peridotite with onshore drilling. Sub-seafloor peridotite is extensive off Oman, New Caledonia and Papua New Guinea, with smaller amounts off Spain, Morocco, USA, etc. This would be a regional contribution, used in parallel with other methods elsewhere. To achieve larger scale is conceivable. There is a giant mass of seafloor peridotite along slow-spreading mid-ocean ridges. Could robotic drills enhance CO2 uptake at a reasonable cost, while fabric chimneys transport CO2-depleted water to the sea surface? Does anyone know James Cameron's phone number? [1] O

Extraction of Seabed/Subsurface Features in a Potential CO2 Sequestration Site in the Southern Baltic Sea, Using Wavelet Transform of High-resolution Sub-Bottom Profiler Data

Science.gov (United States)

Tegowski, J.; Zajfert, G.

2014-12-01

Carbon Capture & Storage (CCS) efficiently prevents the release of anthropogenic CO2 into the atmosphere. We investigate a potential site in the Polish Sector of the Baltic Sea (B3 field site), consisting in a depleted oil and gas reservoir. An area ca. 30 x 8 km was surveyed along 138 acoustic transects, realised from R/V St. Barbara in 2012 and combining multibeam echosounder, sidescan sonar and sub-bottom profiler. Preparation of CCS sites requires accurate knowledge of the subsurface structure of the seafloor, in particular deposit compactness. Gas leaks in the water column were monitored, along with the structure of upper sediment layers. Our analyses show the shallow sub-seabed is layered, and quantified the spatial distribution of gas diffusion chimneys and seabed effusion craters. Remote detection of gas-containing surface sediments can be rather complex if bubbles are not emitted directly into the overlying water and thus detectable acoustically. The heterogeneity of gassy sediments makes conventional bottom sampling methods inefficient. Therefore, we propose a new approach to identification, mapping, and monitoring of potentially gassy surface sediments, based on wavelet analysis of echo signal envelopes of a chirp sub-bottom profiler (EdgeTech SB-0512). Each echo envelope was subjected to wavelet transformation, whose coefficients were used to calculate wavelet energies. The set of echo envelope parameters was input to fuzzy logic and c-means algorithms. The resulting classification highlights seafloor areas with different subsurface morphological features, which can indicate gassy sediments. This work has been conducted under EC FP7-CP-IP project No. 265847: Sub-seabed CO2 Storage: Impact on Marine Ecosystems (ECO2).

The Shallow Subsurface Geological Structures at the Chang'E-3 Landing Site Based on Lunar Penetrating Radar Channel-2B Data

Science.gov (United States)

Zhao, N.; Zhu, P.; Yuan, Y.; Yang, K.; Xiao, L.; Xiao, Z.

2014-12-01

The Lunar Penetrating Radar (LPR) carried by the Yutu rover of the Chinese Chang'E-3 mission has detected the shallow subsurface structures for the landing site at the northern Mare Imbrium. The antenna B of the LPR Channel-2 has collected more than 2000 traces of usable raw data. We performed calibration on the LPR data including amplitude compensation, filtering, and deconvolution. The processed results reveal that the shallow subsurface of the landing site can be divided into three major layers whose thicknesses are ~1, ~3, and 2-7 m, respectively. Variations occur on the thickness of each layer at different locations. Considering the geological background of the landing site, we interpret that the first layer is the regolith layer accumulated over ~80 Ma since the formation of the 450 m diameter Chang'E A crater. This regolith layer was formed on the basis of the ejecta deposits of Chang'E A. The second layer is the remnant continuous ejecta deposits from the Chang'E A crater, which is thicker closer to the crater rim and thinning outwardly. The Chang'E A crater formed on a paleo-regolith layer over the Eratosthenian basalts, which represents the third layer detected by the Channel 2B of the LPR.

The pH and pCO2 dependence of sulfate reduction in shallow-sea hydrothermal CO2 - venting sediments (Milos Island, Greece).

Science.gov (United States)

Bayraktarov, Elisa; Price, Roy E; Ferdelman, Timothy G; Finster, Kai

2013-01-01

Microbial sulfate reduction (SR) is a dominant process of organic matter mineralization in sulfate-rich anoxic environments at neutral pH. Recent studies have demonstrated SR in low pH environments, but investigations on the microbial activity at variable pH and CO2 partial pressure are still lacking. In this study, the effect of pH and pCO2 on microbial activity was investigated by incubation experiments with radioactive (35)S targeting SR in sediments from the shallow-sea hydrothermal vent system of Milos, Greece, where pH is naturally decreased by CO2 release. Sediments differed in their physicochemical characteristics with distance from the main site of fluid discharge. Adjacent to the vent site (T ~40-75°C, pH ~5), maximal sulfate reduction rates (SRR) were observed between pH 5 and 6. SR in hydrothermally influenced sediments decreased at neutral pH. Sediments unaffected by hydrothermal venting (T ~26°C, pH ~8) expressed the highest SRR between pH 6 and 7. Further experiments investigating the effect of pCO2 on SR revealed a steep decrease in activity when the partial pressure increased from 2 to 3 bar. Findings suggest that sulfate reducing microbial communities associated with hydrothermal vent system are adapted to low pH and high CO2, while communities at control sites required a higher pH for optimal activity.

Transport of Chemical Vapors from Subsurface Sources to Atmosphere as Affected by Shallow Subsurface and Atmospheric Conditions

Science.gov (United States)

Rice, A. K.; Smits, K. M.; Hosken, K.; Schulte, P.; Illangasekare, T. H.

2012-12-01

Understanding the movement and modeling of chemical vapor through unsaturated soil in the shallow subsurface when subjected to natural atmospheric thermal and mass flux boundary conditions at the land surface is of importance to applications such as landmine detection and vapor intrusion into subsurface structures. New, advanced technologies exist to sense chemical signatures at the land/atmosphere interface, but interpretation of these sensor signals to make assessment of source conditions remains a challenge. Chemical signatures are subject to numerous interactions while migrating through the unsaturated soil environment, attenuating signal strength and masking contaminant source conditions. The dominant process governing movement of gases through porous media is often assumed to be Fickian diffusion through the air phase with minimal or no quantification of other processes contributing to vapor migration, such as thermal diffusion, convective gas flow due to the displacement of air, expansion/contraction of air due to temperature changes, temporal and spatial variations of soil moisture and fluctuations in atmospheric pressure. Soil water evaporation and interfacial mass transfer add to the complexity of the system. The goal of this work is to perform controlled experiments under transient conditions of soil moisture, temperature and wind at the land/atmosphere interface and use the resulting dataset to test existing theories on subsurface gas flow and iterate between numerical modeling efforts and experimental data. Ultimately, we aim to update conceptual models of shallow subsurface vapor transport to include conditionally significant transport processes and inform placement of mobile sensors and/or networks. We have developed a two-dimensional tank apparatus equipped with a network of sensors and a flow-through head space for simulation of the atmospheric interface. A detailed matrix of realistic atmospheric boundary conditions was applied in a series of

STOMP Subsurface Transport Over Multiple Phases: STOMP-CO2 and STOMP-CO2e Guide: Version 1.0

Energy Technology Data Exchange (ETDEWEB)

White, Mark D.; Bacon, Diana H.; McGrail, B. Peter; Watson, David J.; White, Signe K.; Zhang, Z. F.

2012-04-03

This STOMP (Subsurface Transport Over Multiple Phases) guide document describes the theory, use, and application of the STOMP-CO2 and STOMP-CO2e operational modes. These operational modes of the STOMP simulator are configured to solve problems involving the sequestration of CO2 in geologic saline reservoirs. STOMP-CO2 is the isothermal version and STOMP-CO2e is the nonisothermal version. These core operational modes solve the governing conservation equations for component flow and transport through geologic media; where, the STOMP-CO2 components are water, CO2 and salt and the STOMP-CO2e operational mode also includes an energy conservation equation. Geochemistry can be included in the problem solution via the ECKEChem (Equilibrium-Conservation-Kinetic-Equation Chemistry) module, and geomechanics via the EPRMech (Elastic-Plastic-Rock Mechanics) module. This addendum is designed to provide the new user with a full guide for the core capabilities of the STOMP-CO2 and -CO2e simulators, and to provide the experienced user with a quick reference on implementing features. Several benchmark problems are provided in this addendum, which serve as starting points for developing inputs for more complex problems and as demonstrations of the simulator’s capabilities.

Sugarcane vinasse CO2 gasification and release of ash-forming matters in CO2 and N2 atmospheres.

Science.gov (United States)

Dirbeba, Meheretu Jaleta; Brink, Anders; DeMartini, Nikolai; Lindberg, Daniel; Hupa, Mikko

2016-10-01

Gasification of sugarcane vinasse in CO2 and the release of ash-forming matters in CO2 and N2 atmospheres were investigated using a differential scanning calorimetry and thermogravimetric analyzer (DSC-TGA) at temperatures between 600 and 800°C. The results showed that pyrolysis is the main mechanism for the release of the organics from vinasse. Release of ash-forming matters in the vinasse is the main cause for vinasse char weight losses in the TGA above 700°C. The losses are higher in N2 than in CO2, and increase considerably with temperature. CO2 gasification also consumes the carbon in the vinasse chars while suppressing alkali release. Alkali release was also significant due to volatilization of KCl and reduction of alkali sulfate and carbonate by carbon. The DSC measured thermal events during heating up in N2 atmosphere that correspond to predicted melting temperatures of alkali salts in the char. Copyright © 2016 Elsevier Ltd. All rights reserved.

Controlled CO2 injection into a shallow aquifer and leakage detection monitoring practices at the K-COSEM site, Korea

Science.gov (United States)

Lee, S. S.; Joun, W.; Ju, Y. J.; Ha, S. W.; Jun, S. C.; Lee, K. K.

2017-12-01

Artificial carbon dioxide injection into a shallow aquifer system was performed with two injection types imitating short- and long-term CO2 leakage events into a shallow aquifer. One is pulse type leakage of CO2 (6 hours) under a natural hydraulic gradient (0.02) and the other is long-term continuous injection (30 days) under a forced hydraulic gradient (0.2). Injection and monitoring tests were performed at the K-COSEM site in Eumseong, Korea where a specially designed well field had been installed for artificial CO2 release tests. CO2-infused and tracer gases dissolved groundwater was injected through a well below groundwater table and monitoring were conducted in both saturated and unsaturated zones. Real-time monitoring data on CO2 concentration and hydrochemical parameters, and periodical measurements of several gas tracers (He, Ar, Kr, SF6) were obtained. The pulse type short-term injection test was carried out prior to the long-term injection test. Results of the short-term injection test, under natural hydraulic gradient, showed that CO2 plume migrated along the preferential pathway identified through hydraulic interference tests. On the other hand, results of the long-term injection test indicated the CO2 plume migration path was aligned to the forced hydraulic gradient. Compared to the short-term test, the long-term injection formed detectable CO2 concentration change in unsaturated wellbores. Recovery data of tracer gases made breakthrough curves compatible to numerical simulation results. The monitoring results indicated that detection of CO2 leakage into groundwater was more effectively performed by using a pumping and monitoring method in order to capture by-passing plume. With this concept, an effective real-time monitoring method was proposed. Acknowledgement: Financial support was provided by the "R&D Project on Environmental Management of Geologic CO2storage" from the KEITI (Project number : 2014001810003)

Microbially catalyzed nitrate-dependent metal/radionuclide oxidation in shallow subsurface sediments

Science.gov (United States)

Weber, K.; Healy, O.; Spanbauer, T. L.; Snow, D. D.

2011-12-01

Anaerobic, microbially catalyzed nitrate-dependent metal/radionuclide oxidation has been demonstrated in a variety of sediments, soils, and groundwater. To date, studies evaluating U bio-oxidation and mobilization have primarily focused on anthropogenically U contaminated sites. In the Platte River Basin U originating from weathering of uranium-rich igneous rocks in the Rocky Mountains was deposited in shallow alluvial sediments as insoluble reduced uranium minerals. These reduced U minerals are subject to reoxidation by available oxidants, such nitrate, in situ. Soluble uranium (U) from natural sources is a recognized contaminant in public water supplies throughout the state of Nebraska and Colorado. Here we evaluate the potential of anaerobic, nitrate-dependent microbially catalyzed metal/radionuclide oxidation in subsurface sediments near Alda, NE. Subsurface sediments and groundwater (20-64ft.) were collected from a shallow aquifer containing nitrate (from fertilizer) and natural iron and uranium. The reduction potential revealed a reduced environment and was confirmed by the presence of Fe(II) and U(IV) in sediments. Although sediments were reduced, nitrate persisted in the groundwater. Nitrate concentrations decreased, 38 mg/L to 30 mg/L, with increasing concentrations of Fe(II) and U(IV). Dissolved U, primarily as U(VI), increased with depth, 30.3 μg/L to 302 μg/L. Analysis of sequentially extracted U(VI) and U(IV) revealed that virtually all U in sediments existed as U(IV). The presence of U(IV) is consistent with reduced Fe (Fe(II)) and low reduction potential. The increase in aqueous U concentrations with depth suggests active U cycling may occur at this site. Tetravalent U (U(IV)) phases are stable in reduced environments, however the input of an oxidant such as oxygen or nitrate into these systems would result in oxidation. Thus co-occurrence of nitrate suggests that nitrate could be used by bacteria as a U(IV) oxidant. Most probable number

The pH and pCO2 dependence of sulfate reduction in shallow-sea hydrothermal CO2 – venting sediments (Milos Island, Greece)

Science.gov (United States)

Bayraktarov, Elisa; Price, Roy E.; Ferdelman, Timothy G.; Finster, Kai

2013-01-01

Microbial sulfate reduction (SR) is a dominant process of organic matter mineralization in sulfate-rich anoxic environments at neutral pH. Recent studies have demonstrated SR in low pH environments, but investigations on the microbial activity at variable pH and CO2 partial pressure are still lacking. In this study, the effect of pH and pCO2 on microbial activity was investigated by incubation experiments with radioactive 35S targeting SR in sediments from the shallow-sea hydrothermal vent system of Milos, Greece, where pH is naturally decreased by CO2 release. Sediments differed in their physicochemical characteristics with distance from the main site of fluid discharge. Adjacent to the vent site (T ~40–75°C, pH ~5), maximal sulfate reduction rates (SRR) were observed between pH 5 and 6. SR in hydrothermally influenced sediments decreased at neutral pH. Sediments unaffected by hydrothermal venting (T ~26°C, pH ~8) expressed the highest SRR between pH 6 and 7. Further experiments investigating the effect of pCO2 on SR revealed a steep decrease in activity when the partial pressure increased from 2 to 3 bar. Findings suggest that sulfate reducing microbial communities associated with hydrothermal vent system are adapted to low pH and high CO2, while communities at control sites required a higher pH for optimal activity. PMID:23658555

Numerical studies of CO2 and brine leakage into a shallow aquifer through an open wellbore

Science.gov (United States)

Wang, Jingrui; Hu, Litang; Pan, Lehua; Zhang, Keni

2018-03-01

Industrial-scale geological storage of CO2 in saline aquifers may cause CO2 and brine leakage from abandoned wells into shallow fresh aquifers. This leakage problem involves the flow dynamics in both the wellbore and the storage reservoir. T2Well/ECO2N, a coupled wellbore-reservoir flow simulator, was used to analyze CO2 and brine leakage under different conditions with a hypothetical simulation model in water-CO2-brine systems. Parametric studies on CO2 and brine leakage, including the salinity, excess pore pressure (EPP) and initially dissolved CO2 mass fraction, are conducted to understand the mechanism of CO2 migration. The results show that brine leakage rates increase proportionally with EPP and inversely with the salinity when EPP varies from 0.5 to 1.5 MPa; however, there is no CO2 leakage into the shallow freshwater aquifer if EPP is less than 0.5 MPa. The dissolved CO2 mass fraction shows an important influence on the CO2 plume, as part of the dissolved CO2 becomes a free phase. Scenario simulation shows that the gas lifting effect will significantly increase the brine leakage rate into the shallow freshwater aquifer under the scenario of 3.89% dissolved CO2 mass fraction. The equivalent porous media (EPM) approach used to model the wellbore flow has been evaluated and results show that the EPM approach could either under- or over-estimate brine leakage rates under most scenarios. The discrepancies become more significant if a free CO2 phase evolves. Therefore, a model that can correctly describe the complex flow dynamics in the wellbore is necessary for investigating the leakage problems.

Marine Microphytobenthic Assemblage Shift along a Natural Shallow-Water CO2 Gradient Subjected to Multiple Environmental Stressors

OpenAIRE

Johnson, V; Brownlee, C; Milazzo, M; Hall-Spencer, J

2015-01-01

Predicting the effects of anthropogenic CO2 emissions on coastal ecosystems requires an understanding of the responses of algae, since these are a vital functional component of shallow-water habitats. We investigated microphytobenthic assemblages on rock and sandy habitats along a shallow subtidal pCO2 gradient near volcanic seeps in the Mediterranean Sea. Field studies of natural pCO2 gradients help us understand the likely effects of ocean acidification because entire communities are subjec...

Characteristics of CO2 release from forest soil in the mountains near Beijing.

Science.gov (United States)

Sun, Xiang Yang; Gao, Cheng Da; Zhang, Lin; Li, Su Yan; Qiao, Yong

2011-04-01

CO2 release from forest soil is a key driver of carbon cycling between the soil and atmosphere ecosystem. The rate of CO2 released from soil was measured in three forest stands (in the mountainous region near Beijing, China) by the alkaline absorption method from 2004 to 2006. The rate of CO2 released did not differ among the three stands. The CO2 release rate ranged from - 341 to 1,193 mg m(-2) h(-1), and the mean value over all three forests and sampling times was 286 mg m(-2) h(-1). CO2 release was positively correlated with soil water content and the soil temperature. Diurnally, CO2 release was higher in the day than at night. Seasonally, CO2 release was highest in early autumn and lowest in winter; in winter, negative values of CO2 release suggested that CO2 was absorbed by soil.

Upscaling the Coupled Water and Heat Transport in the Shallow Subsurface

Science.gov (United States)

Sviercoski, R. F.; Efendiev, Y.; Mohanty, B. P.

2018-02-01

Predicting simultaneous movement of liquid water, water vapor, and heat in the shallow subsurface has many practical interests. The demand for multidimensional multiscale models for this region is important given: (a) the critical role that these processes play in the global water and energy balances, (b) that more data from air-borne and space-borne sensors are becoming available for parameterizations of modeling efforts. On the other hand, numerical models that consider spatial variations of the soil properties, termed here as multiscale, are prohibitively expensive. Thus, there is a need for upscaled models that take into consideration these features, and be computationally affordable. In this paper, a multidimensional multiscale model coupling the water flow and heat transfer and its respective upscaled version are proposed. The formulation is novel as it describes the multidimensional and multiscale tensorial versions of the hydraulic conductivity and the vapor diffusivity, taking into account the tortuosity and porosity properties of the medium. It also includes the coupling with the energy balance equation as a boundary describing atmospheric influences at the shallow subsurface. To demonstrate the accuracy of both models, comparisons were made between simulation and field experiments for soil moisture and temperature at 2, 7, and 12 cm deep, during 11 days. The root-mean-square errors showed that the upscaled version of the system captured the multiscale features with similar accuracy. Given the good matching between simulated and field data for near-surface soil temperature, the results suggest that it can be regarded as a 1-D variable.

Shallow Aquifer Vulnerability From Subsurface Fluid Injection at a Proposed Shale Gas Hydraulic Fracturing Site

Science.gov (United States)

Wilson, M. P.; Worrall, F.; Davies, R. J.; Hart, A.

2017-11-01

Groundwater flow resulting from a proposed hydraulic fracturing (fracking) operation was numerically modeled using 91 scenarios. Scenarios were chosen to be a combination of hydrogeological factors that a priori would control the long-term migration of fracking fluids to the shallow subsurface. These factors were induced fracture extent, cross-basin groundwater flow, deep low hydraulic conductivity strata, deep high hydraulic conductivity strata, fault hydraulic conductivity, and overpressure. The study considered the Bowland Basin, northwest England, with fracking of the Bowland Shale at ˜2,000 m depth and the shallow aquifer being the Sherwood Sandstone at ˜300-500 m depth. Of the 91 scenarios, 73 scenarios resulted in tracked particles not reaching the shallow aquifer within 10,000 years and 18 resulted in travel times less than 10,000 years. Four factors proved to have a statistically significant impact on reducing travel time to the aquifer: increased induced fracture extent, absence of deep high hydraulic conductivity strata, relatively low fault hydraulic conductivity, and magnitude of overpressure. Modeling suggests that high hydraulic conductivity formations can be more effective barriers to vertical flow than low hydraulic conductivity formations. Furthermore, low hydraulic conductivity faults can result in subsurface pressure compartmentalization, reducing horizontal groundwater flow, and encouraging vertical fluid migration. The modeled worst-case scenario, using unlikely geology and induced fracture lengths, maximum values for strata hydraulic conductivity and with conservative tracer behavior had a particle travel time of 130 years to the base of the shallow aquifer. This study has identified hydrogeological factors which lead to aquifer vulnerability from shale exploitation.

Predicting the Stochastic Properties of the Shallow Subsurface for Improved Geophysical Modeling

Science.gov (United States)

Stroujkova, A.; Vynne, J.; Bonner, J.; Lewkowicz, J.

2005-12-01

Strong ground motion data from numerous explosive field experiments and from moderate to large earthquakes show significant variations in amplitude and waveform shape with respect to both azimuth and range. Attempts to model these variations using deterministic models have often been unsuccessful. It has been hypothesized that a stochastic description of the geological medium is a more realistic approach. To estimate the stochastic properties of the shallow subsurface, we use Measurement While Drilling (MWD) data, which are routinely collected by mines in order to facilitate design of blast patterns. The parameters, such as rotation speed of the drill, torque, and penetration rate, are used to compute the rock's Specific Energy (SE), which is then related to a blastability index. We use values of SE measured at two different mines and calibrated to laboratory measurements of rock properties to determine correlation lengths of the subsurface rocks in 2D, needed to obtain 2D and 3D stochastic models. The stochastic models are then combined with the deterministic models and used to compute synthetic seismic waveforms.

Metagenomic Evidence for H2 Oxidation and H2 Production by Serpentinite-Hosted Subsurface Microbial Communities

Science.gov (United States)

Brazelton, William J.; Nelson, Bridget; Schrenk, Matthew O.

2012-01-01

Ultramafic rocks in the Earth’s mantle represent a tremendous reservoir of carbon and reducing power. Upon tectonic uplift and exposure to fluid flow, serpentinization of these materials generates copious energy, sustains abiogenic synthesis of organic molecules, and releases hydrogen gas (H2). In order to assess the potential for microbial H2 utilization fueled by serpentinization, we conducted metagenomic surveys of a marine serpentinite-hosted hydrothermal chimney (at the Lost City hydrothermal field) and two continental serpentinite-hosted alkaline seeps (at the Tablelands Ophiolite, Newfoundland). Novel [NiFe]-hydrogenase sequences were identified at both the marine and continental sites, and in both cases, phylogenetic analyses indicated aerobic, potentially autotrophic Betaproteobacteria belonging to order Burkholderiales as the most likely H2-oxidizers. Both sites also yielded metagenomic evidence for microbial H2 production catalyzed by [FeFe]-hydrogenases in anaerobic Gram-positive bacteria belonging to order Clostridiales. In addition, we present metagenomic evidence at both sites for aerobic carbon monoxide utilization and anaerobic carbon fixation via the Wood–Ljungdahl pathway. In general, our results point to H2-oxidizing Betaproteobacteria thriving in shallow, oxic–anoxic transition zones and the anaerobic Clostridia thriving in anoxic, deep subsurface habitats. These data demonstrate the feasibility of metagenomic investigations into novel subsurface habitats via surface-exposed seeps and indicate the potential for H2-powered primary production in serpentinite-hosted subsurface habitats. PMID:22232619

Metagenomic evidence for h(2) oxidation and h(2) production by serpentinite-hosted subsurface microbial communities.

Science.gov (United States)

Brazelton, William J; Nelson, Bridget; Schrenk, Matthew O

2012-01-01

Ultramafic rocks in the Earth's mantle represent a tremendous reservoir of carbon and reducing power. Upon tectonic uplift and exposure to fluid flow, serpentinization of these materials generates copious energy, sustains abiogenic synthesis of organic molecules, and releases hydrogen gas (H(2)). In order to assess the potential for microbial H(2) utilization fueled by serpentinization, we conducted metagenomic surveys of a marine serpentinite-hosted hydrothermal chimney (at the Lost City hydrothermal field) and two continental serpentinite-hosted alkaline seeps (at the Tablelands Ophiolite, Newfoundland). Novel [NiFe]-hydrogenase sequences were identified at both the marine and continental sites, and in both cases, phylogenetic analyses indicated aerobic, potentially autotrophic Betaproteobacteria belonging to order Burkholderiales as the most likely H(2)-oxidizers. Both sites also yielded metagenomic evidence for microbial H(2) production catalyzed by [FeFe]-hydrogenases in anaerobic Gram-positive bacteria belonging to order Clostridiales. In addition, we present metagenomic evidence at both sites for aerobic carbon monoxide utilization and anaerobic carbon fixation via the Wood-Ljungdahl pathway. In general, our results point to H(2)-oxidizing Betaproteobacteria thriving in shallow, oxic-anoxic transition zones and the anaerobic Clostridia thriving in anoxic, deep subsurface habitats. These data demonstrate the feasibility of metagenomic investigations into novel subsurface habitats via surface-exposed seeps and indicate the potential for H(2)-powered primary production in serpentinite-hosted subsurface habitats.

Metagenomic evidence for H2 oxidation and H2 production by serpentinite-hosted subsurface microbial communities

Directory of Open Access Journals (Sweden)

William J Brazelton

2012-01-01

Full Text Available Ultramafic rocks in the Earth’s mantle represent a tremendous reservoir of carbon and reducing power. Upon tectonic uplift and exposure to fluid flow, serpentinization of these materials generates copious energy, sustains abiogenic synthesis of organic molecules, and releases hydrogen gas (H2. In order to assess the potential for microbial H2 utilization fueled by serpentinization, we conducted metagenomic surveys of a marine serpentinite-hosted hydrothermal chimney (at the Lost City hydrothermal field and two continental serpentinite- hosted alkaline seeps (at the Tablelands Ophiolite, Newfoundland. Novel [NiFe]-hydrogenase sequences were identified at both the marine and continental sites, and in both cases, phylogenetic analyses indicated aerobic, potentially autotrophic Betaproteobacteria belonging to order Burkholderiales as the most likely H2-oxidizers. Both sites also yielded metagenomic evidence for microbial H2 production catalyzed by [FeFe]-hydrogenases in anaerobic Gram- positive bacteria belonging to order Clostridiales. In addition, we present metagenomic evidence at both sites for aerobic carbon monoxide utilization and anaerobic carbon fixation via the Wood-Ljungdahl pathway. In general, our results point to H2-oxidizing Betaproteobacteria thriving in shallow, oxic-anoxic transition zones and the anaerobic Clostridia thriving in anoxic, deep subsurface habitats. These data demonstrate the feasibility of metagenomic investigations into novel subsurface habitats via surface-exposed seeps and indicate the potential for H2- powered primary production in serpentinite-hosted subsurface habitats.

Characterizing Microbial Diversity and Function in Natural Subsurface CO2 Reservoir Systems for Applied Use in Geologic Carbon Sequestration Environments

Science.gov (United States)

Freedman, A.; Thompson, J. R.

2013-12-01

The injection of CO2 into geological formations at quantities necessary to significantly reduce CO2 emissions will represent an environmental perturbation on a continental scale. The extent to which biological processes may play a role in the fate and transport of CO2 injected into geological formations has remained an open question due to the fact that at temperatures and pressures associated with reservoirs targeted for sequestration CO2 exists as a supercritical fluid (scCO2), which has generally been regarded as a sterilizing agent. Natural subsurface accumulations of CO2 serve as an excellent analogue for studying the long-term effects, implications and benefits of CO2 capture and storage (CCS). While several geologic formations bearing significant volumes of nearly pure scCO2 phases have been identified in the western United States, no study has attempted to characterize the microbial community present in these systems. Because the CO2 in the region is thought to have first accumulated millions of years ago, it is reasonable to assume that native microbial populations have undergone extensive and unique physiological and behavioral adaptations to adjust to the exceedingly high scCO2 content. Our study focuses on the microbial communities associated with the dolomite limestone McElmo Dome scCO2 Field in the Colorado Plateau region, approximately 1,000 m below the surface. Fluid samples were collected from 10 wells at an industrial CO2 production facility outside Cortez, CO. Subsamples preserved on site in 3.7% formaldehyde were treated in the lab with Syto 9 green-fluorescent nucleic acid stain, revealing 3.2E6 to 1.4E8 microbial cells per liter of produced fluid and 8.0E9 cells per liter of local pond water used in well drilling fluids. Extracted DNAs from sterivex 0.22 um filters containing 20 L of sample biomass were used as templates for PCR targeting the 16S rRNA gene. 16S rRNA amplicons from these samples were cloned, sequenced and subjected to microbial

Subsurface iron and arsenic removal for shallow tube well drinking water supply in rural Bangladesh.

Science.gov (United States)

van Halem, D; Olivero, S; de Vet, W W J M; Verberk, J Q J C; Amy, G L; van Dijk, J C

2010-11-01

Subsurface iron and arsenic removal has the potential to be a cost-effective technology to provide safe drinking water in rural decentralized applications, using existing shallow tube wells. A community-scale test facility in Bangladesh was constructed for injection of aerated water (∼1 m(3)) into an anoxic aquifer with elevated iron (0.27 mmolL(-1)) and arsenic (0.27μmolL(-1)) concentrations. The injection (oxidation) and abstraction (adsorption) cycles were monitored at the test facility and simultaneously simulated in the laboratory with anoxic column experiments. Dimensionless retardation factors (R) were determined to represent the delayed arrival of iron or arsenic in the well compared to the original groundwater. At the test facility the iron removal efficacies increased after every injection-abstraction cycle, with retardation factors (R(Fe)) up to 17. These high removal efficacies could not be explained by the theory of adsorptive-catalytic oxidation, and therefore other ((a)biotic or transport) processes have contributed to the system's efficacy. This finding was confirmed in the anoxic column experiments, since the mechanism of adsorptive-catalytic oxidation dominated in the columns and iron removal efficacies did not increase with every cycle (stable at R(Fe)=∼8). R(As) did not increase after multiple cycles, it remained stable around 2, illustrating that the process which is responsible for the effective iron removal did not promote the co-removal of arsenic. The columns showed that subsurface arsenic removal was an adsorptive process and only the freshly oxidized adsorbed iron was available for the co-adsorption of arsenic. This indicates that arsenic adsorption during subsurface treatment is controlled by the amount of adsorbed iron that is oxidized, and not by the amount of removed iron. For operational purposes this is an important finding, since apparently the oxygen concentration of the injection water does not control the subsurface arsenic

Transient modeling of electrochemically assisted CO2 capture and release

DEFF Research Database (Denmark)

Singh, Shobhana; Stechel, Ellen B.; Buttry, Daniel A.

2017-01-01

to analyze the time-dependent behavior of CO2 capture and electro-migration transport across the cell length. Given high nonlinearity of the system, we used a finite element method (FEM) to numerically solve the coupled mass transport equations. The model describes the concentration profiles by taking......The present work aims to develop a model of a new electrochemical CO2 separation and release technology. We present a one-dimensional transient model of an electrochemical cell for point source CO2 capture and release, which mainly focuses on the simultaneous mass transport and complex chemical...... reactions associated with the separation process. For concreteness, we use an ionic liquid (IL) with 2 M thiolate anion (RS−) in 1 M disulfide (RSSR) as an electrolyte in the electrochemical cell to capture, transport and release CO2 under standard operating conditions. We computationally solved the model...

Time-Lapse Electrical Resistivity Investigations for Imaging the Grouting Injection in Shallow Subsurface Cavities

Directory of Open Access Journals (Sweden)

Muhammad Farooq

2014-01-01

Full Text Available The highway of Yongweol-ri, Muan-gun, south-western part of the South Korean Peninsula, is underlain by the abandoned of subsurface cavities, which were discovered in 2005. These cavities lie at shallow depths with the range of 5∼15 meters below the ground surface. Numerous subsidence events have repeatedly occurred in the past few years, damaging infrastructure and highway. As a result of continuing subsidence issues, the Korean Institute of Geosciences and Mineral Resources (KIGAM was requested by local administration to resolve the issue. The KIGAM used geophysical methods to delineate subsurface cavities and improve more refined understanding of the cavities network in the study area. Cement based grouting has been widely employed in the construction industry to reinforce subsurface ground. In this research work, time-lapse electrical resistivity surveys were accomplished to monitor the grouting injection in the subsurface cavities beneath the highway, which have provided a quasi-real-time monitoring for modifying the subsurface cavities related to ground reinforcement, which would be difficult with direct methods. The results obtained from time-lapse electrical resistivity technique have satisfactory imaged the grouting injection experiment in the subsurface cavities beneath the highway. Furthermore, the borehole camera confirmed the presence of grouting material in the subsurface cavities, and hence this procedure increases the mechanical resistance of subsurface cavities below the highway.

Preliminary Study of Favourable Formations for CO{sub 2} Subsurface Storage in Spain; Estudio Preliminar de las Formaciones Favorables para el Almacenamiento Subterraneo de CO{sub 2} en Espana

Energy Technology Data Exchange (ETDEWEB)

Zapatero, M. A.; Reyes, J. L.; Martinez, R.; Suarez, I.; Arenillas, A.; Perucha, M. A.

2009-10-12

This report is a synthesis of the possibilities of CO{sub 2} storage in the Spanish subsurface. Compilation and analysis of geological information has been carried out, looking at surface and subsurface, in order to make a pre-selection of potential favourable units for CO{sub 2} storage, taking in account that each of this storages needs a confining formation to seal the storage. Before the storage selection, a general description of the great geological units of the Iberian Peninsula is done. Afterwards, borehole logging from petroleum exploration is analysed in these units, formations and areas of interest. The aim is to finally obtain a description of selected units and their possibilities of CO{sub 2} storage. (Author) 17 refs.

Nature and Distribution of Stable Subsurface Oxygen in Copper Electrodes During Electrochemical CO2 Reduction

DEFF Research Database (Denmark)

Cavalca, Filippo Carlo; Ferragut, Rafael; Aghion, Stefano

2017-01-01

Oxide-derived copper (OD-Cu) electrodes exhibit higher activity than pristine copper during the carbon dioxide reduction reaction (CO2RR) and higher selectivity towards ethylene. The presence of residual subsurface oxygen in OD-Cu has been proposed to be responsible for such improvements, although...

Geochemical and hydrological characterization of shallow aquifer water following a nearby deep CO2 injection in Wellington, Kansas

Science.gov (United States)

Datta, S.; Andree, I.; Johannesson, K. H.; Kempton, P. D.; Barker, R.; Birdie, T. R.; Watney, W. L.

2017-12-01

Salinization or CO2 leakage from local Enhanced Oil Recovery (EOR) projects has become a possible source for contamination and water quality degradation for local irrigation or potable well users in Wellington, Kansas. Shallow domestic and monitoring wells, as well as surface water samples collected from the site, were analyzed for a wide array of geochemical proxies including major and trace ions, rare earth elements (REE), stable isotopes, dissolved organic carbon and dissolved hydrocarbons; these analytes were employed as geotracers to understand the extent of hydrologic continuity throughout the Paleozoic stratigraphic section. Previous research by Barker et al. (2012) laid the foundation through a mineralogical and geochemical investigation of the Arbuckle injection zone and assessment of overlying caprock integrity, which led to the conclusion that the 4,910-5,050' interval will safely sequester CO2 with high confidence of a low leakage potential. EOR operations using CO2 as the injectant into the Mississippian 3,677-3,706' interval was initiated in Jan 2016. Two groundwater sampling events were conducted to investigate any temporal changes in the surface and subsurface waters. Dissolved (Ca+Mg)/Na and Na/Cl mass ratio values of two domestic wells and one monitoring well ranged from 0.67 to 2.01 and 0.19 to 0.39, respectively, whereas a nearby Mississippian oil well had values of 0.20 and 0.62, respectively . δ18O and δ2H ranged from -4.74 to -5.41 ‰VSMOW and -31.4 to -34.3 ‰VSMOW, respectively, among the domestic wells and shallowest monitoring well. Conservative ion relationships in drill-stem-test waters from Arbuckle and Mississippian injection zones displayed significant variability, indicating limited vertical hydrologic communication. Total aquifer connectivity is inconclusive based on the provided data; however, a paleoterrace and incised valley within the study site are thought to be connected through a Mississippian salt plume migration

Next generation of CO2 enhanced water recovery with subsurface energy storage in China

Science.gov (United States)

Li, Qi; Kühn, Michael; Ma, Jianli; Niu, Zhiyong

2017-04-01

Carbon dioxide (CO2) utilization and storage (CCUS) is very popular in comparison with traditional CO2 capture and storage (CCS) in China. In particular, CO2 storage in deep saline aquifers with enhanced water recovery (CO2-EWR) [1] is gaining more and more attention as a cleaner production technology. The CO2-EWR was written into the "U.S.-China Joint Announcement on Climate Change" released November 11, 2014. "Both sides will work to manage climate change by demonstrating a new frontier for CO2 use through a carbon capture, use, and sequestration (CCUS) project that will capture and store CO2 while producing fresh water, thus demonstrating power generation as a net producer of water instead of a water consumer. This CCUS project with enhanced water recovery will eventually inject about 1.0 million tonnes of CO2 and create approximately 1.4 million cubic meters of freshwater per year." In this article, at first we reviewed the history of the CO2-EWR and addressed its current status in China. Then, we put forth a new generation of the CO2-EWR with emphasizing the collaborative solutions between carbon emission reductions and subsurface energy storage or renewable energy cycle [2]. Furthermore, we figured out the key challenging problems such as water-CCUS nexus when integrating the CO2-EWR with the coal chemical industry in the Junggar Basin, Xinjiang, China [3-5]. Finally, we addressed some crucial problems and strategic consideration of the CO2-EWR in China with focuses on its technical bottleneck, relative advantage, early opportunities, environmental synergies and other related issues. This research is not only very useful for the current development of CCUS in the relative "cold season" but also beneficial for the energy security and clean production in China. [1] Li Q, Wei Y-N, Liu G, Shi H (2015) CO2-EWR: a cleaner solution for coal chemical industry in China. Journal of Cleaner Production 103:330-337. doi:10.1016/j.jclepro.2014.09.073 [2] Streibel M

Hydrogeochemical and mineralogical effects of sustained CO₂ contamination in a shallow sandy aquifer: A field-scale controlled release experiment

DEFF Research Database (Denmark)

Cahill, Aaron Graham; Marker, Pernille Aabye; Jakobsen, Rasmus

2014-01-01

A shallow aquifer CO2 contamination experiment was performed to investigate evolution of water chemistry and sediment alteration following leakage from geological storage by physically simulating a leak from a hypothetical storage site. In a carbonate-free aquifer, in western Denmark, a total...... of 1600 kg of gas phase CO2 was injected at 5 and 10 m depth over 72 days through four inclined injection wells into aeolian and glacial sands. Water chemistry was monitored for pH, EC, and dissolved element evolution through an extensive network of multilevel sampling points over 305 days. Sediment cores...... were taken pre and postinjection and analyzed to search for effects on mineralogy and sediment properties. Results showed the simulated leak to evolve in two distinct phases; an advective elevated ion pulse followed by increasing persistent acidification. Spatial and temporal differences in evolution...

Research Project on CO2 Geological Storage and Groundwater Resources: Water Quality Effects Caused by CO2 Intrusion into Shallow Groundwater

Energy Technology Data Exchange (ETDEWEB)

Birkholzer, Jens; Apps, John; Zheng, Liange; Zhang, Yingqi; Xu, Tianfu; Tsang, Chin-Fu

2008-10-01

One promising approach to reduce greenhouse gas emissions is injecting CO{sub 2} into suitable geologic formations, typically depleted oil/gas reservoirs or saline formations at depth larger than 800 m. Proper site selection and management of CO{sub 2} storage projects will ensure that the risks to human health and the environment are low. However, a risk remains that CO{sub 2} could migrate from a deep storage formation, e.g. via local high-permeability pathways such as permeable faults or degraded wells, and arrive in shallow groundwater resources. The ingress of CO{sub 2} is by itself not typically a concern to the water quality of an underground source of drinking water (USDW), but it will change the geochemical conditions in the aquifer and will cause secondary effects mainly induced by changes in pH, in particular the mobilization of hazardous inorganic constituents present in the aquifer minerals. Identification and assessment of these potential effects is necessary to analyze risks associated with geologic sequestration of CO{sub 2}. This report describes a systematic evaluation of the possible water quality changes in response to CO{sub 2} intrusion into aquifers currently used as sources of potable water in the United States. Our goal was to develop a general understanding of the potential vulnerability of United States potable groundwater resources in the event of CO{sub 2} leakage. This goal was achieved in two main tasks, the first to develop a comprehensive geochemical model representing typical conditions in many freshwater aquifers (Section 3), the second to conduct a systematic reactive-transport modeling study to quantify the effect of CO{sub 2} intrusion into shallow aquifers (Section 4). Via reactive-transport modeling, the amount of hazardous constituents potentially mobilized by the ingress of CO{sub 2} was determined, the fate and migration of these constituents in the groundwater was predicted, and the likelihood that drinking water

The design of long wavelength planetary SAR sensor and its applications for monitoring shallow sub-surface of Moon and planets.

Science.gov (United States)

Kim, K.

2015-12-01

SAR observations over planetary surface have been conducted mainly in two ways. The first is the subsurface sounding, for example Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) and Shallow Surface Radar (SHARAD), using ground penetration capability of long wavelength electromagnetic waves. On the other hand, imaging SAR sensors using burst mode design have been employed to acquire surface observations in the presence of opaque atmospheres such as in the case of Venus and Titan. We propose a lightweight SAR imaging system with P/L band wavelength to cover the vertical observation gap of these planetary radar observation schemes. The sensor is for investigating prominent surface and near-subsurface geological structures and physical characteristics. Such measurements will support landers and rover missions as well as future manned missions. We evaluate required power consumption, and estimate mass and horizontal resolution, which can be as good as 3-7 meters. Initial specifications for P/L dual band SARs for the lunar case at 130 km orbital altitude were designed already based on a assumptions that sufficient size antenna (>3m width diameter or width about 3m and >10kg weight) can be equipped. Useful science measurements to be obtained include: (1) derivation of subsurface regolith depth; 2) Surface and shallow subsurface radar imaging, together with radar ranging techniques such as radargrammetry and inteferometry. The concepts in this study can be used as an important technical basis for the future solid plant/satellite missions and already proposed for the 2018 Korean Lunar mission.

CO2 Sparging Phase 3 Full Scale Implementation and Monitoring Report

Science.gov (United States)

In-situ carbon dioxide (CO2) sparging was designed and implemented to treat a subsurface causticbrine pool (CBP) formed as a result of releases from historical production of industrial chemicals at theLCP Chemicals Site, Brunswick, GA (Site).

Intrinsic Fiber Optic Chemical Sensors for Subsurface Detection of CO₂

Energy Technology Data Exchange (ETDEWEB)

Alonso, Jesus [Intelligent Optical Systems, Inc., Torrance, CA (United States)

2016-01-01

Intelligent Optical Systems, Inc. has developed distributed intrinsic fiber optic sensors to directly quantify the concentration of dissolved or gas-phase CO₂ for leak detection or plume migration in carbon capture and sequestration (CCS). The capability of the sensor for highly sensitive detection of CO₂ in the pressure and temperature range of 15 to 2,000 psi and 25°C to 175°C was demonstrated, as was the capability of operating in highly corrosive and contaminated environments such as those often found in CO₂ injection sites. The novel sensor system was for the first time demonstrated deployed in a deep well, detecting multiple CO₂ releases, in real time, at varying depths. Early CO₂ release detection, by means of a sensor cable integrating multiple sensor segments, was demonstrated, as was the capability of quantifying the leak. The novel fiber optic sensor system exhibits capabilities not achieved by any other monitoring technology. This project represents a breakthrough in monitoring capabilities for CCS applications.

LIBS Sensor for Sub-surface CO2 Leak Detection in Carbon Sequestration

Directory of Open Access Journals (Sweden)

Jinesh JAIN

2017-07-01

Full Text Available Monitoring carbon sequestration poses numerous challenges to the sensor community. For example, the subsurface environment is notoriously harsh, with large potential mechanical, thermal, and chemical stresses, making long-term stability and survival a challenge to any potential in situ monitoring method. Laser induced breakdown spectroscopy (LIBS has been demonstrated as a promising technology for chemical monitoring of harsh environments and hard to reach places. LIBS has a real- time monitoring capability and can be used for the elemental and isotopic analysis of solid, liquid, and gas samples. The flexibility of the probe design and the use of fiber- optics has made LIBS particularly suited for remote measurements. The paper focuses on developing a LIBS instrument for downhole high-pressure, high-temperature brine experiments, where CO2 leakage could result in changes in the trace mineral composition of an aquifer. The progress in fabricating a compact, robust, and simple LIBS sensor for widespread subsurface leak detection is presented.

CO2 Huff-n-Puff Process in a Light Oil Shallow Shelf Carbonate Reservoir

Energy Technology Data Exchange (ETDEWEB)

Boomer, R.J.; Cole, R.; Kovar, M.; Prieditis, J.; Vogt, J.; Wehner, S.

1999-02-24

The application cyclic CO2, often referred to as the CO2 Huff-n-Puff process, may find its niche in the maturing waterfloods of the Permian Basin. Coupling the CO2 Huff-n-Puff process to miscible flooding applications could provide the needed revenue to sufficiently mitigate near-term negative cash flow concerns in capital-intensive miscible projects. Texaco Exploration and Production Inc. and the US Department of Energy have teamed up in a attempt to develop the CO2 Huff-n-Puff process in the Grayburg and San Andres formations which are light oil, shallow shelf carbonate reservoirs that exist throughout the Permian Basin. This cost-shared effort is intended to demonstrate the viability of this underutilized technology in a specific class of domestic reservoir.

Adaptive management for subsurface pressure and plume control in application to geological CO2 storage

Science.gov (United States)

Gonzalez-Nicolas, A.; Cihan, A.; Birkholzer, J. T.; Petrusak, R.; Zhou, Q.; Riestenberg, D. E.; Trautz, R. C.; Godec, M.

2016-12-01

Industrial-scale injection of CO2 into the subsurface can cause reservoir pressure increases that must be properly controlled to prevent any potential environmental impact. Excessive pressure buildup in reservoir may result in ground water contamination stemming from leakage through conductive pathways, such as improperly plugged abandoned wells or distant faults, and the potential for fault reactivation and possibly seal breaching. Brine extraction is a viable approach for managing formation pressure, effective stress, and plume movement during industrial-scale CO2 injection projects. The main objectives of this study are to investigate suitable different pressure management strategies involving active brine extraction and passive pressure relief wells. Adaptive optimized management of CO2 storage projects utilizes the advanced automated optimization algorithms and suitable process models. The adaptive management integrates monitoring, forward modeling, inversion modeling and optimization through an iterative process. In this study, we employ an adaptive framework to understand primarily the effects of initial site characterization and frequency of the model update (calibration) and optimization calculations for controlling extraction rates based on the monitoring data on the accuracy and the success of the management without violating pressure buildup constraints in the subsurface reservoir system. We will present results of applying the adaptive framework to test appropriateness of different management strategies for a realistic field injection project.

Ring Resonator for Detection of Melting Brine Under Shallow Subsurface of Mars

Science.gov (United States)

Ponchak, George E.; Jordan, Jennifer L.; Scardelletti, Maximilian C.

2016-01-01

Laboratory experimental evidence using Raman spectroscopy has shown that liquid brine may form below the shallow subsurface of Mars. A simpler experimental method to verify the presence of liquid brine or liquid water below Mars surface is needed. In this paper, a ring resonator is used to detect the phase change between frozen water and liquid water below a sandy soil that simulates the Mars surface. Experimental data shows that the ring resonator can detect the melting of thin layers of frozen brine or water up to 15 mm below the surface.

Subsurface watering resulted in reduced soil N2O and CO2 emissions and their global warming potentials than surface watering

Science.gov (United States)

Wei, Qi; Xu, Junzeng; Yang, Shihong; Liao, Linxian; Jin, Guangqiu; Li, Yawei; Hameed, Fazli

2018-01-01

Water management is an important practice with significant effect on greenhouse gases (GHG) emission from soils. Nitrous oxide (N2O) and carbon dioxide (CO2) emissions and their global warming potentials (GWPs) from subsurface watering soil (SUW) were investigated, with surface watering (SW) as a control. Results indicated that the N2O and CO2 emissions from SUW soils were somewhat different to those from SW soil, with the peak N2O and CO2 fluxes from SUW soil reduced by 28.9% and 19.4%, and appeared 72 h and 168 h later compared with SW. The fluxes of N2O and CO2 from SUW soils were lower than those from SW soil in both pulse and post-pulse periods, and the reduction was significantly (p0.1) lower that from SW soil. Moreover, N2O and CO2 fluxes from both watering treatments increased exponentially with increase of soil water-filled pore space (WFPS) and temperature. Our results suggest that watering soil from subsurface could significantly reduce the integrative greenhouse effect caused by N2O and CO2 and is a promising strategy for soil greenhouse gases (GHGs) mitigation. And the pulse period, contributed most to the reduction in emissions of N2O and CO2 from soils between SW and SUW, should be a key period for mitigating GHGs emissions. Response of N2O and CO2 emissions to soil WFPS and temperature illustrated that moisture was the dominant parameters that triggering GHG pulse emissions (especially for N2O), and temperature had a greater effect on the soil microorganism activity than moisture in drier soil. Avoiding moisture and temperature are appropriate for GHG emission at the same time is essential for GHGs mitigation, because peak N2O and CO2 emission were observed only when moisture and temperature are both appropriate.

Simple dielectric mixing model in the monitoring of CO2 leakage from geological storage aquifer

Science.gov (United States)

Abidoye, L. K.; Bello, A. A.

2017-03-01

The principle of the dielectric mixing for multiphase systems in porous media has been employed to investigate CO2-water-porous media system and monitor the leakage of CO2, in analogy to scenarios that can be encountered in geological carbon sequestration. A dielectric mixing model was used to relate the relative permittivity for different subsurface materials connected with the geological carbon sequestration. The model was used to assess CO2 leakage and its upward migration, under the influences of the depth-dependent characteristics of the subsurface media as well as the fault-connected aquifers. The results showed that for the upward migration of CO2 in the subsurface, the change in the bulk relative permittivity (εb) of the CO2-water-porous media system clearly depicts the leakage and movement of CO2, especially at depth shallower than 800 m. At higher depth, with higher pressure and temperature, the relative permittivity of CO2 increases with pressure, while that of water decreases with temperature. These characteristics of water and supercritical CO2, combine to limit the change in the εb, at higher depth. Furthermore, it was noted that if the pore water was not displaced by the migrating CO2, the presence of CO2 in the system increases the εb. But, with the displacement of pore water by the migrating CO2, it was shown how the εb profile decreases with time. Owing to its relative simplicity, composite dielectric behaviour of multiphase materials can be effectively deployed for monitoring and enhancement of control of CO2 movement in the geological carbon sequestration.

Assessment of particle size distribution in CO 2 accidental releases

NARCIS (Netherlands)

Hulsbosch-Dam, C.E.C.; Spruijt, M.P.N.; Necci, A.; Cozzani, V.

2012-01-01

A model was developed to calculate the particle size distribution following the release of pressurised supercritical CO 2. The model combines several sub-models for the different stages of jet break-up and specifically addresses the possible formation of solid particles, which is important for CO 2

Using the Bongwana natural CO2 release to understand leakage processes and develop monitoring

Science.gov (United States)

Jones, David; Johnson, Gareth; Hicks, Nigel; Bond, Clare; Gilfillan, Stuart; Kremer, Yannick; Lister, Bob; Nkwane, Mzikayise; Maupa, Thulani; Munyangane, Portia; Robey, Kate; Saunders, Ian; Shipton, Zoe; Pearce, Jonathan; Haszeldine, Stuart

2016-04-01

Natural CO2 leakage along the Bongwana Fault in South Africa is being studied to help understand processes of CO2 leakage and develop monitoring protocols. The Bongwana Fault crops out over approximately 80 km in KwaZulu-Natal province, South Africa. In outcrop the fault is expressed as a broad fracture corridor in Dwyka Tillite, with fractures oriented approximately N-S. Natural emissions of CO2 occur at various points along the fault, manifest as travertine cones and terraces, bubbling in the rivers and as gas fluxes through soil. Exposed rock outcrop shows evidence for Fe-staining around fractures and is locally extensively kaolinitised. The gas has also been released through a shallow water well, and was exploited commercially in the past. Preliminary studies have been carried out to better document the surface emissions using near surface gas monitoring, understand the origin of the gas through major gas composition and stable and noble gas isotopes and improve understanding of the structural controls on gas leakage through mapping. In addition the impact of the leaking CO2 on local water sources (surface and ground) is being investigated, along with the seismic activity of the fault. The investigation will help to build technical capacity in South Africa and to develop monitoring techniques and plans for a future CO2 storage pilot there. Early results suggest that CO2 leakage is confined to a relatively small number of spatially-restricted locations along the weakly seismically active fault. Fracture permeability appears to be the main method by which the CO2 migrates to the surface. The bulk of the CO2 is of deep origin with a minor contribution from near surface biogenic processes as determined by major gas composition. Water chemistry, including pH, DO and TDS is notably different between CO2-rich and CO2-poor sites. Soil gas content and flux effectively delineates the fault trace in active leakage sites. The fault provides an effective testing ground for

Toward physical aspects affecting a possible leakage of geologically stored CO₂ into the shallow subsurface

DEFF Research Database (Denmark)

Singh, Ashok; Delfs, Jens Olaf; Görke, Uwe Jens

2014-01-01

In geological formations, migration of CO2 plume is very complex and irregular. To make CO2 capture and storage technology feasible, it is important to quantify CO2 amount associated with possible leakage through natural occurring faults and fractures in geologic medium. Present work examines the...

Assessment of brine migration risks along vertical pathways due to CO2 injection

Science.gov (United States)

Kissinger, Alexander; Class, Holger

2015-04-01

Global climate change, shortage of resources and the growing usage of renewable energy sources has lead to a growing demand for the utilization of subsurface systems. Among these competing uses are Carbon Capture and Storage (CCS), geothermal energy, nuclear waste disposal, 'renewable' methane or hydrogen storage as well as the ongoing production of fossil resources like oil, gas and coal. Additionally, these technologies may also create conflicts with essential public interests such as water supply. For example, the injection of CO2 into the subsurface causes an increase in pressure reaching far beyond the actual radius of influence of the CO2 plume, potentially leading to large amounts of displaced salt water. In this work we focus on the large scale impacts of CO2 storage on brine migration but the methodology and the obtained results may also apply to other fields like waste water disposal, where large amounts of fluid are injected into the subsurface. In contrast to modeling on the reservoir scale the spatial scale required for this work is much larger in both vertical and lateral direction, as the regional hydrogeology has to be considered. Structures such as fault zones, hydrogeological windows in the Rupelian clay or salt domes are considered as potential pathways for displaced fluids into shallow systems and their influence has to be taken into account. We put the focus of our investigations on the latter type of scenario, since there is still a poor understanding of the role that salt diapirs would play in CO2 storage projects. As there is hardly any field data available on this scale, we compare different levels of model complexity in order to identify the relevant processes for brine displacement and simplify the modeling process wherever possible, for example brine injection vs. CO2 injection, simplified geometries vs. the complex formation geometry and the role of salt induced density differences on flow. Further we investigate the impact of the

Biological CO2 conversion to acetate in subsurface coal-sand formation using a high-pressure reactor system

Directory of Open Access Journals (Sweden)

Yoko eOhtomo

2013-12-01

Full Text Available Geological CO2 sequestration in unmineable subsurface oil/gas fields and coal formations has been proposed as a means of reducing anthropogenic greenhouse gasses in the atmosphere. However, the feasibility of injecting CO2 into subsurface depends upon a variety of geological and economic conditions, and the ecological consequences are largely unpredictable. In this study, we developed a new flow-through-type reactor system to examine potential geophysical, geochemical and microbiological impacts associated with CO2 injection by simulating in situ pressure (0–100 MPa and temperature (0–70°C conditions. Using the reactor system, anaerobic artificial fluid and CO2 (flow rate: 0.002 and 0.00001 mL/min, respectively were continuously supplemented into a column comprised of bituminous coal and sand under a pore pressure of 40 MPa (confined pressure: 41 MPa at 40°C for 56 days. 16S rRNA gene analysis of the bacterial components showed distinct spatial separation of the predominant taxa in the coal and sand over the course of the experiment. Cultivation experiments using sub-sampled fluids revealed that some microbes survived, or were metabolically active, under CO2-rich conditions. However, no methanogens were activated during the experiment, even though hydrogenotrophic and methylotrophic methanogens were obtained from conventional batch-type cultivation at 20°C. During the reactor experiment, the acetate and methanol concentration in the fluids increased while the δ13Cacetate, H2 and CO2 concentrations decreased, indicating the occurrence of homo-acetogenesis. 16S rRNA genes of homo-acetogenic spore-forming bacteria related to the genus Sporomusa were consistently detected from the sandstone after the reactor experiment. Our results suggest that the injection of CO2 into a natural coal-sand formation preferentially stimulates homo-acetogenesis rather than methanogenesis, and that this process is accompanied by biogenic CO2 conversion to

Natural and industrial analogues for leakage of CO2 from storagereservoirs: identification of features, events, and processes and lessonslearned

Energy Technology Data Exchange (ETDEWEB)

Lewicki, Jennifer L.; Birkholzer, Jens; Tsang, Chin-Fu

2006-02-28

The injection and storage of anthropogenic CO2 in deepgeologic formations is a potentially feasible strategy to reduce CO2emissions and atmospheric concentrations. While the purpose of geologiccarbon storage is to trap CO2 underground, CO2 could migrate away fromthe storage site into the shallow subsurface and atmosphere if permeablepathways such as well bores or faults are present. Large-magnitudereleases of CO2 have occurred naturally from geologic reservoirs innumerous volcanic, geothermal, and sedimentary basin settings. Carbondioxide and natural gas have also been released from geologic CO2reservoirs and natural gas storage facilities, respectively, due toinfluences such as well defects and injection/withdrawal processes. Thesesystems serve as natural and industrial analogues for the potentialrelease of CO2 from geologic storage reservoirs and provide importantinformation about the key features, events, and processes (FEPs) that areassociated with releases, as well as the health, safety, andenvironmental consequences of releases and mitigation efforts that can beapplied. We describe a range of natural releases of CO2 and industrialreleases of CO2 and natural gas in the context of these characteristics.Based on this analysis, several key conclusions can be drawn, and lessonscan be learned for geologic carbon storage. First, CO2 can bothaccumulate beneath, and be released from, primary and secondaryreservoirs with capping units located at a wide range of depths. Bothprimary and secondary reservoir entrapments for CO2 should therefore bewell characterized at storage sites. Second, many natural releases of CO2have been correlated with a specific event that triggered the release,such as magmatic fluid intrusion or seismic activity. The potential forprocesses that could cause geomechanical damage to sealing cap rocks andtrigger the release of CO2 from a storage reservoir should be evaluated.Third, unsealed fault and fracture zones may act as fast and directconduits

CO2-Induced ATP-Dependent Release of Acetylcholine on the Ventral Surface of the Medulla Oblongata.

Science.gov (United States)

Huckstepp, Robert T R; Llaudet, Enrique; Gourine, Alexander V

2016-01-01

Complex mechanisms that detect changes in brainstem parenchymal PCO2/[H+] and trigger adaptive changes in lung ventilation are responsible for central respiratory CO2 chemosensitivity. Previous studies of chemosensory signalling pathways suggest that at the level of the ventral surface of the medulla oblongata (VMS), CO2-induced changes in ventilation are (at least in part) mediated by the release and actions of ATP and/or acetylcholine (ACh). Here we performed simultaneous real-time biosensor recordings of CO2-induced ATP and ACh release from the VMS in vivo and in vitro, to test the hypothesis that central respiratory CO2 chemosensory transduction involves simultaneous recruitment of purinergic and cholinergic signalling pathways. In anaesthetised and artificially ventilated rats, an increase in inspired CO2 triggered ACh release on the VMS with a peak amplitude of ~5 μM. Release of ACh was only detected after the onset of CO2-induced activation of the respiratory activity and was markedly reduced (by ~70%) by ATP receptor blockade. In horizontal slices of the VMS, CO2-induced release of ATP was reliably detected, whereas CO2 or bath application of ATP (100 μM) failed to trigger release of ACh. These results suggest that during hypercapnia locally produced ATP induces or potentiates the release of ACh (likely from the medullary projections of distal groups of cholinergic neurones), which may also contribute to the development and/or maintenance of the ventilatory response to CO2.

Subsurface investigation on Quarter 27 of May 15th city, Cairo, Egypt using electrical resistivity tomography and shallow seismic refraction techniques

Directory of Open Access Journals (Sweden)

Sultan Awad Sultan Araffa

2014-12-01

Full Text Available Geophysical tools such as electrical resistivity tomography (ERT and shallow seismic (both P-wave seismic refraction and Multi-channel Analysis of Surface Waves (MASW are interesting techniques for delineating the subsurface configurations as stratigraphy, structural elements, caves and water saturated zones. The ERT technique is used to delineate the contamination, to detect the buried objects, and to quantify some aquifer properties. Eight 2-D (two dimensional electrical resistivity sections were measured using two different configurations (dipole–dipole and Wenner. The spread length is of 96 m and the electrodes spacing are 2, 4 and 6 m, respectively to reach a depth ranging from 13 to 17 m. The results indicate that, the subsurface section is divided into main three geo-electrical units, the first is fractured marl and limestone which exhibits high resistivity values ranging from 40 to 300 ohm m. The second unit is corresponding to marl of moderate resistivity values and the third unit, which is the deeper unit, exhibits very low resistivity values corresponding to clayey marl. The fourth layer is marly clay with water. The presence of clay causes the most geotechnical problems. Fourteen shallow seismic sections (both for P-wave and MASW were carried out using spread of 94 m and geophone spacing of 2 m for each P-wave section. The results demonstrate that the deduced subsurface section consists of four layers, the first layer exhibits very low P-wave velocity ranging from 280 to 420 m/s, the second layer reveals P-wave velocity ranging from 400 to 1200 m/s, the third layer has P-wave velocity ranging from 970 to 2000 m/s and the fourth layer exhibits high velocity ranging from 1900 to 3600 m/s. The ERT and shallow seismic results, reflect the presence of two parallel faults passing through Quarter 27 and trending NW-SE.

Effect of subalpine canopy removal on snowpack, soil solution, and nutrient export, Fraser Experimental Forest, CO

Science.gov (United States)

Stottlemyer, R.; Troendle, C.A.

1999-01-01

Research on the effects of vegetation manipulation on snowpack, soil water, and streamwater chemistry and flux has been underway at the Fraser Experimental Forest (FEF), CO, since 1982. Greater than 95% of FEF snowmelt passes through watersheds as subsurface flow where soil processes significantly alter meltwater chemistry. To better understand the mechanisms accounting for annual variation in watershed streamwater ion concentration and flux with snowmelt, we studied subsurface water flow, its ion concentration, and flux in conterminous forested and clear cut plots. Repetitive patterns in subsurface flow and chemistry were apparent. Control plot subsurface flow chemistry had the highest ion concentrations in late winter and fall. When shallow subsurface flow occurred, its Ca2+, SO42-, and HCO3- concentrations were lower and K+ higher than deep flow. The percentage of Ca2+, NO3-, SO42-, and HCO3- flux in shallow depths was less and K+ slightly greater than the percentage of total flow. Canopy removal increased precipitation reaching the forest floor by about 40%, increased peak snowpack water equivalent (SWE) > 35%, increased the average snowpack Ca2+, NO3-, and NH4+ content, reduced the snowpack K+ content, and increased the runoff four-fold. Clear cutting doubled the percentage of subsurface flow at shallow depths, and increased K+ concentration in shallow subsurface flow and NO3- concentrations in both shallow and deep flow. The percentage change in total Ca2+, SO42-, and HCO3- flux in shallow depths was less than the change in water flux, while that of K+ and NO3- flux was greater. Relative to the control, in the clear cut the percentage of total Ca2+ flux at shallow depths increased from 5 to 12%, SO42- 5.4 to 12%, HCO3- from 5.6 to 8.7%, K+ from 6 to 35%, and NO3- from 2.7 to 17%. The increases in Ca2+ and SO42- flux were proportional to the increase in water flux, the flux of HCO3- increased proportionally less than water flux, and NO3- and K+ were

CO2 Sequestration short course

Energy Technology Data Exchange (ETDEWEB)

DePaolo, Donald J. [Lawrence Berkeley National Laboratory; Cole, David R [The Ohio State University; Navrotsky, Alexandra [University of California-Davis; Bourg, Ian C [Lawrence Berkeley National Laboratory

2014-12-08

Given the public’s interest and concern over the impact of atmospheric greenhouse gases (GHGs) on global warming and related climate change patterns, the course is a timely discussion of the underlying geochemical and mineralogical processes associated with gas-water-mineral-interactions encountered during geological sequestration of CO2. The geochemical and mineralogical processes encountered in the subsurface during storage of CO2 will play an important role in facilitating the isolation of anthropogenic CO2 in the subsurface for thousands of years, thus moderating rapid increases in concentrations of atmospheric CO2 and mitigating global warming. Successful implementation of a variety of geological sequestration scenarios will be dependent on our ability to accurately predict, monitor and verify the behavior of CO2 in the subsurface. The course was proposed to and accepted by the Mineralogical Society of America (MSA) and The Geochemical Society (GS).

Comparison of CO₂ Detection Methods Tested in Shallow Groundwater Monitoring Wells at a Geological Sequestration Site

Energy Technology Data Exchange (ETDEWEB)

Edenborn, Harry M.; Jain, Jinesh N.

2016-05-17

The geological storage of anthropogenic carbon dioxide (CO₂) is one method of reducing the amount of CO₂ released into the atmosphere. Monitoring programs typically determine baseline conditions in surface and near-surface environments before, during, and after CO₂ injection to evaluate if impacts related to injection have occurred. Because CO₂ concentrations in groundwater fluctuate naturally due to complex geochemical and geomicrobiologicalinteractions, a clear understanding of the baseline behavior of CO₂ in groundwater near injection sites is important. Numerous ways of measuring aqueous CO₂ in the field and lab are currently used, but most methods have significant shortcomings (e.g., are tedious, lengthy, have interferences, or have significant lag time before a result is determined). In this study, we examined the effectiveness of two novel CO₂ detection methods and their ability to rapidly detect CO2in shallow groundwater monitoring wells associated with the Illinois Basin –Decatur Project geological sequestration site. The CarboQC beverage carbonation meter was used to measure the concentration of CO₂ in water by monitoring temperature and pressure changes and calculating the PCO₂ from the ideal gas law. Additionally, a non-dispersive infrared (NDIR) CO< sub>2sensor enclosed in a gas-permeable, water-impermeable membrane measured CO2by determining an equilibrium concentration. Results showed that the CarboQC method provided rapid (< 3 min) and repeatable results under field conditions within a measured concentration range of 15 –125 mg/L CO₂. The NDIR sensor results correlated well (r²= 0.93) with the CarboQC data, but CO₂ equilibration required at least 15 minutes, making the method somewhat less desirable under field conditions. In contrast, NDIR-based sensors have a greater potential for long-term deployment. Both

Optimal Control of Partially Miscible Two-Phase Flow with Applications to Subsurface CO2 Sequestration

KAUST Repository

Simon, Moritz; Ulbrich, Michael

2013-01-01

Motivated by applications in subsurface CO2 sequestration, we investigate constrained optimal control problems with partially miscible two-phase flow in porous media. The objective is, e.g., to maximize the amount of trapped CO2 in an underground reservoir after a fixed period of CO2 injection, where the time-dependent injection rates in multiple wells are used as control parameters. We describe the governing two-phase two-component Darcy flow PDE system and formulate the optimal control problem. For the discretization we use a variant of the BOX method, a locally conservative control-volume FE method. The timestep-wise Lagrangian of the control problem is implemented as a functional in the PDE toolbox Sundance, which is part of the HPC software Trilinos. The resulting MPI parallelized Sundance state and adjoint solvers are linked to the interior point optimization package IPOPT. Finally, we present some numerical results in a heterogeneous model reservoir.

Growth of Co on Cu(111), Subsurface growth of trilayer Co islands

DEFF Research Database (Denmark)

Pedersen, M.Ø.; Bönicke, I.A.; Lægsgaard, E.

1997-01-01

The growth of cobalt on Cu(lll) has been studied using a variable-temperature scanning tunneling microscope (STM). Al a deposition temperature of 150 K, one observes the growth of three-layer Co islands with one subsurface layer. The Co islands are surrounded by a brim of Cu. The distinction...

Element mobilization and immobilization from carbonate rocks between CO 2 storage reservoirs and the overlying aquifers during a potential CO 2 leakage

Energy Technology Data Exchange (ETDEWEB)

Lawter, Amanda R.; Qafoku, Nikolla P.; Asmussen, R. Matthew; Kukkadapu, Ravi K.; Qafoku, Odeta; Bacon, Diana H.; Brown, Christopher F.

2018-04-01

Despite the numerous studies on changes within the reservoir following CO2 injection and the effects of CO2 release into overlying aquifers, little or no literature is available on the effect of CO2 release on rock between the storage reservoirs and subsurface. To address this knowledge gap, relevant rock materials, temperatures and pressures were used to study mineralogical and elemental changes in this intermediate zone. After rocks reacted with CO2, liquid analysis showed an increase of major elements (e.g., Ca, and Mg) and variable concentrations of potential contaminants (e.g., Sr and Ba); lower concentrations were observed in N2 controls. In experiments with As/Cd and/or organic spikes, representing potential contaminants in the CO2 plume originating in the storage reservoir, most or all of these contaminants were removed from the aqueous phase. SEM and Mössbauer spectroscopy results showed the formation of new minerals and Fe oxides in some CO2-reacted samples, indicating potential for contaminant removal through mineral incorporation or adsorption onto Fe oxides. These experiments show the interactions between the CO2-laden plume and the rock between storage reservoirs and overlying aquifers have the potential to affect the level of risk to overlying groundwater, and should be considered during site selection and risk evaluation.

An estimation of the electrical characteristics of planetary shallow subsurfaces with TAPIR antennas

Science.gov (United States)

Le Gall, A.; Reineix, A.; Ciarletti, V.; Berthelier, J. J.; Ney, R.; Dolon, F.; Corbel, C.

2006-06-01

In the frame of the NETLANDER program, we have developed the Terrestrial And Planetary Investigation by Radar (TAPIR) imaging ground-penetrating radar to explore the Martian subsurface at kilometric depths and search for potential water reservoirs. This instrument which is to operate from a fixed lander is based on a new concept which allows one to image the various underground reflectors by determining the direction of propagation of the reflected waves. The electrical parameters of the shallow subsurface (permittivity and conductivity) need to be known to correctly determine the propagation vector. In addition, these electrical parameters can bring valuable information on the nature of the materials close to the surface. The electric antennas of the radar are 35 m long resistively loaded monopoles that are laid on the ground. Their impedance, measured during a dedicated mode of operation of the radar, depends on the electrical parameters of soil and is used to infer the permittivity and conductivity of the upper layer of the subsurface. This paper presents an experimental and theoretical study of the antenna impedance and shows that the frequency profile of the antenna complex impedance can be used to retrieve the geoelectrical characteristics of the soil. Comparisons between a numerical modeling and in situ measurements have been successfully carried over various soils, showing a very good agreement.

Impact of CO_2 on the Evolution of Microbial Communities Exposed to Carbon Storage Conditions, Enhanced Oil Recovery, and CO_2 Leakage

International Nuclear Information System (INIS)

Gulliver, Djuna M.; Gregory, Kelvin B.; Lowry, Gregory V.

2016-01-01

Geologic carbon storage (GCS) is a crucial part of a proposed mitigation strategy to reduce the anthropogenic carbon dioxide (CO_2) emissions to the atmosphere. During this process, CO_2 is injected as super critical carbon dioxide (SC-CO_2) in confined deep subsurface storage units, such as saline aquifers and depleted oil reservoirs. The deposition of vast amounts of CO_2 in subsurface geologic formations could unintentionally lead to CO_2 leakage into overlying freshwater aquifers. Introduction of CO_2 into these subsurface environments will greatly increase the CO_2 concentration and will create CO_2 concentration gradients that drive changes in the microbial communities present. While it is expected that altered microbial communities will impact the biogeochemistry of the subsurface, there is no information available on how CO_2 gradients will impact these communities. The overarching goal of this project is to understand how CO_2 exposure will impact subsurface microbial communities at temperatures and pressures that are relevant to GCS and CO_2 leakage scenarios. To meet this goal, unfiltered, aqueous samples from a deep saline aquifer, a depleted oil reservoir, and a fresh water aquifer were exposed to varied concentrations of CO_2 at reservoir pressure and temperature. The microbial ecology of the samples was examined using molecular, DNA-based techniques. The results from these studies were also compared across the sites to determine any existing trends. Results reveal that increasing CO_2 leads to decreased DNA concentrations regardless of the site, suggesting that microbial processes will be significantly hindered or absent nearest the CO_2 injection/leakage plume where CO_2 concentrations are highest. At CO_2 exposures expected downgradient from the CO_2 plume, selected microorganisms emerged as dominant in the CO_2 exposed conditions. Results suggest that the altered microbial community was site specific and highly dependent on pH. The site

Experimental and modeling results on geochemical impacts of leaking CO2 from subsurface storage reservoirs to an unconfined oxidizing carbonate aquifer

Science.gov (United States)

Qafoku, N. P.; Bacon, D. H.; Shao, H.; Lawter, A.; Wang, G.; Brown, C. F.

2013-12-01

Deep subsurface storage and sequestration of CO2 has been identified as a potential mitigation technique for rising atmospheric CO2 concentrations. Sequestered CO2 represents a potential risk to overlying aquifers if the CO2 leaks from the deep storage reservoir. Experimental and modeling work is required to evaluate risks to groundwater quality and develop a systematic understanding on how CO2 leakage may cause important changes in aquifer chemistry and mineralogy by promoting dissolution/precipitation, adsorption/desorption, and redox reactions. Solid materials (rocks and slightly weathered rocks) from an unconfined aquifer, i.e., the Edwards Aquifer in Texas, were used in this investigation. The experimental part consisted of: 1) wet chemical acid extractions (8M HNO3 solution at 90 0C); 2) batch experiments conducted at low solid to solution ratios to study time-dependent releases of major, minor and trace elements during periodic or continuous exposure to CO2 gas; 3) hydraulically saturated column experiments conducted under continuous and stop-flow conditions using a CO2 gas saturated synthetic groundwater; 4) pre- and post-treatment solid phase characterization studies. Major variables tested included reaction time (0-336 hours), CO2 flow rate (50 to 350 ml/min), brine concentration (0.1 and 1 M NaCl), rock type and particle size fraction. We are currently investigating the solution composition effects (i.e., presence of contaminants in the initial solution) on the fate and behavior of potential contaminants (As, Pb and Cd) in these systems. Results from the solid phase characterization studies showed that the mineralogy of the Edwards aquifer materials was dominated by calcite. Quartz and montmorillonite were also present in some samples. Acid extractions confirmed that the solid phase had appreciable amounts of potential contaminants (As, Cd, Cr, Cu, Pb and Zn). However, the results from the batch and column experiments demonstrated that these contaminants

Leakage and Seepage of CO2 from Geologic Carbon Sequestration Sites: CO2 Migration into Surface Water

International Nuclear Information System (INIS)

Oldenburg, Curt M.; Lewicki, Jennifer L.

2005-01-01

ebullition and bubble flow will be the dominant form of gas transport in surface water for all but the smallest seepage fluxes or shallowest water bodies. The solubility of the gas species in water plays a fundamental role in whether ebullition occurs. We used a solubility model to examine CO 2 solubility in waters with varying salinity as a function of depth below a 200 m-deep surface water body. In this system, liquid CO 2 is stable between the deep regions where supercritical CO 2 is stable and the shallow regions where gaseous CO 2 is stable. The transition from liquid to gaseous CO 2 is associated with a large change in density, with corresponding large change in bubble buoyancy. The solubility of CO 2 is lower in high-salinity waters such as might be encountered in the deep subsurface. Therefore, as CO 2 migrates upward through the deep subsurface, it will likely encounter less saline water with increasing capacity to dissolve CO 2 potentially preventing ebullition, depending on the CO 2 leakage flux. However, as CO 2 continues to move upward through shallower depths, CO 2 solubility in water decreases strongly leading to greater likelihood of ebullition and bubble flow in surface water. In the case of deep density-stratified lakes in which ebullition is suppressed, enhanced mixing and man-made degassing schemes can alleviate the buildup of CO 2 and related risk of dangerous rapid discharges. Future research efforts are needed to increase understanding of CO 2 leakage and seepage in surface water and saturated porous media. For example, we recommend experiments and field tests of CO 2 migration in saturated systems to formulate bubble-driven water-displacement models and relative permeability functions that can be used in simulation models

An Estimation Of The Geoelectric Features Of Planetary Shallow Subsurfaces With TAPIR Antennae

Science.gov (United States)

Le Gall, A.; Reineix, A.; Ciarletti, V.; Jean-Jacques, B.; Ney, R.; Dolon, F.; Corbel, C.

2005-12-01

Exploring the interior of Mars and searching for water reservoirs, either in the form of ice or of liquid water, was one of the main scientific objectives of the NETLANDER project. In that frame, the CETP (Centre d'Etude des Environnements Terrestre et Planetaires) has developed an imaging ground penetrating radar (GPR), called TAPIR (Terrestrial And Planetary Investigation by Radar). Operating from a fixed position and at low frequencies (from 2 to 4MHz), this instrument allows to retrieve not only the distance but also the inclination of deep subsurface reflectors by measuring the two horizontal electrical components and the three magnetic components of the reflected waves. In 2004, ground tests have been successfully carried out on the Antarctic Continent; the bedrock, lying under a thick layer of ice (until 1200m), was detected and part of its relief was revealed. Yet, knowing the electric parameters of the close subsurface is required to correctly process the measured electric and magnetic components of the echoes and deduce their propagation vector. In addition, these electric parameters can bring a very interesting piece of information on the nature of the material in the shallow underground. We have therefore looked for a possible method (appropriate for a planetary mission) to evaluate them using a special mode of operation of the radar. This method relies on the fact that the electrical characteristics of the transmitting electric antennas (current along the antenna, driving-point impedance.) depend on the nature of the ground on which the radar is lying. If this dependency is significant enough, geological parameters of the subsurface can be deduced from the analysis of specific measurements. We have thus performed a detailed experimental and theoretical study of the TAPIR resistively loaded electrical dipoles to get a precise understanding of the radar transmission and assess the role of the electric parameters of the underground. In this poster, we

Mathematical model of CO2 release during milk fermentation using natural kefir grains.

Science.gov (United States)

Goršek, Andreja; Ritonja, Jožef; Pečar, Darja

2018-03-12

Milk fermentation takes place in the presence of various micro-organisms, producing a variety of dairy products. The oldest of them is kefir, which is usually produced by the fermentation of milk with kefir grains. Carbon dioxide (CO 2 ), as one of the process products, also contributes to the characteristic flavor of kefir. The amount of CO 2 generated during fermentation depends on bioprocessing conditions and may change, which is not desirable at the industrial level. In this study we developed a simplified mathematical model of CO 2 release in the milk-fermentation process. An intuitive approach based on superposition and experimental analysis was used for the modeling. The chemical system studied was considered as a two-input (temperature, rotational frequency of the stirrer) one-output (CO 2 concentration) dynamic system. Based on an analysis of CO 2 release transients in the case of non-simultaneous stepwise changed input quantities, two differential equations were defined that describe the influence of the two input quantities on the output quantity. The simulation results were verified by experiments. The proposed model can be used for a comprehensive analysis of the process that is being studied and for the design and synthesis of advanced control systems, which will ensure a controlled CO 2 release at the industrial level. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

Effect of shallow donors on Curie–Weiss temperature of Co-doped ZnO

Energy Technology Data Exchange (ETDEWEB)

Guo, Shuxia, E-mail: gsx0391@sina.com [Department of Physics, Jiaozuo Teachers College, Jiaozuo 454001 (China); Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng 475004 (China); Li, Jiwu [Department of Physics, Jiaozuo Teachers College, Jiaozuo 454001 (China); Du, Zuliang [Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng 475004 (China)

2014-12-15

Co-doped ZnO and Al, Co co-doped ZnO polycrystalline powders were synthesized by co-precipitation method. The magnetization curves measured at 2 K show no hysteresis neither remanence for all samples. ZnO:Co grown at low temperature has a positive Curie–Weiss temperature Θ, and ZnO:Co grown at high temperature has a negative Θ. But Al-doped ZnO:Co grown at high temperature has a positive Θ. Positive Curie–Weiss temperature Θ was considered to have relation to the presence of shallow donors in the samples. - Highlights: • Co-doped ZnO and Al, Co co-doped ZnO polycrystalline powders were synthesized. • No hysteresis is observed for all samples. • The Curie–Weiss temperature Θ changes its sign by Al doping. • Positive Θ should be related to shallow donors.

Subsurface Contamination Control

Energy Technology Data Exchange (ETDEWEB)

Y. Yuan

2001-12-12

subsurface repository; (2) provides a table of derived LRCL for nuclides of radiological importance; (3) Provides an as low as is reasonably achievable (ALARA) evaluation of the derived LRCL by comparing potential onsite and offsite doses to documented ALARA requirements; (4) Provides a method for estimating potential releases from a defective WP; (5) Provides an evaluation of potential radioactive releases from a defective WP that may become airborne and result in contamination of the subsurface facility; and (6) Provides a preliminary analysis of the detectability of a potential WP leak to support the design of an airborne release monitoring system.

CO-induced Pd segregation and the effect of subsurface Pd on CO adsorption on CuPd surfaces

International Nuclear Information System (INIS)

Padama, A A B; Villaos, R A B; Albia, J R; Diño, W A; Nakanishi, H; Kasai, H

2017-01-01

We report results of our study on the adsorption of CO on CuPd surfaces with bulk stoichiometric and nonstoichiometric layers using density functional theory (DFT). We found that the presence of Pd atoms in the subsurface layer promotes the adsorption of CO. We also observed CO-induced Pd segregation on the CuPd surface and we attribute this to the strong CO–Pd interaction. Lastly, we showed that the adsorption of CO promotes Pd–Pd interaction as compared to the pristine surface which promotes strong Cu–Pd interaction. These results indicate that CO adsorption on CuPd surfaces can be tuned by taking advantage of the CO-induced segregation and by considering the role of subsurface Pd atoms. (paper)

Diffuse CO2 degassing at Vesuvio, Italy

Science.gov (United States)

Frondini, Francesco; Chiodini, Giovanni; Caliro, Stefano; Cardellini, Carlo; Granieri, Domenico; Ventura, Guido

2004-10-01

At Vesuvio, a significant fraction of the rising hydrothermal-volcanic fluids is subjected to a condensation and separation process producing a CO2-rich gas phase, mainly expulsed through soil diffuse degassing from well defined areas called diffuse degassing structures (DDS), and a liquid phase that flows towards the outer part of the volcanic cone. A large amount of thermal energy is associated with the steam condensation process and subsequent cooling of the liquid phase. The total amount of volcanic-hydrothermal CO2 discharged through diffuse degassing has been computed through a sequential Gaussian simulation (sGs) approach based on several hundred accumulation chamber measurements and, at the time of the survey, amounted to 151 t d-1. The steam associated with the CO2 output, computed assuming that the original H2O/CO2 ratio of hydrothermal fluids is preserved in fumarolic effluents, is 553 t d-1, and the energy produced by the steam condensation and cooling of the liquid phase is 1.47×1012 J d-1 (17 MW). The location of the CO2 and temperature anomalies show that most of the gas is discharged from the inner part of the crater and suggests that crater morphology and local stratigraphy exert strong control on CO2 degassing and subsurface steam condensation. The amounts of gas and energy released by Vesuvio are comparable to those released by other volcanic degassing areas of the world and their estimates, through periodic surveys of soil CO2 flux, can constitute a useful tool to monitor volcanic activity.

Hydrogeochemical impact of CO{sub 2} leakage from geological sequestration on shallow potable aquifers

Energy Technology Data Exchange (ETDEWEB)

Cahill, A.G.

2013-09-15

Over the past 10 years scientists have worked in earnest to understand the potential effects of leakage in order that an informed decision on CCGS implementation can be made. This research can be broadly described as aiming to answer two key questions; how deleterious is leakage of CCGS to groundwater resources? and can it be detected geochemically? Some common hydrochemical development is apparent from the literature however many aspects of hydrogeological and hydrogeochemical impact of leakage into shallow aquifers used in water supply remain unclear. In this Ph.D. study an integrated approach was employed in order to answer the two key questions regarding leakage of CO{sub 2} into shallow aquifers. Consequently a combination of laboratory and field investigations were conducted supported by numerical geochemical modeling in order to identify, constrain and quantify processes controlling groundwater chemistry evolution. The output is 4 journal articles and 3 technical reports. In paper I and technical report I simple batch reactors were employed coupled to comprehensive sediment characterization to determine the likely effects of CO{sub 2} on water chemistry in a range of shallow aquifers. Results showed aquifers can be broadly divided into three types; carbonate dominated, silicate dominated and mixed. Each aquifer type showed distinct water chemistry evolution thus inherent risks vary. These studies also highlighted the complexity of risk assessment and detection caused by the range of formation types potentially overlying storage reservoirs. Investigations described in Papers II, III and technical report II increase applicability to real leakage by observing in situ effects including groundwater flow. A silicate dominated shallow aquifer in Vroegum, western Denmark forms the focus of study upon which a series of investigations were conducted. The main field study involved injection of 1600 kg of gas phase CO{sub 2} into the shallow Vroegum aquifer over 72 days

Transient changes in shallow groundwater chemistry during the MSU ZERT CO2 injection experiment

Science.gov (United States)

Apps, J.A.; Zheng, Lingyun; Spycher, N.; Birkholzer, J.T.; Kharaka, Y.; Thordsen, J.; Kakouros, E.; Trautz, R.

2011-01-01

Food-grade CO2 was injected into a shallow aquifer through a perforated pipe placed horizontally 1-2 m below the water table at the Montana State University Zero Emission Research and Technology (MSU-ZERT) field site at Bozeman, Montana. The possible impact of elevated CO2 levels on groundwater quality was investigated by analyzing 80 water samples taken before, during, and following CO2 injection. Field determinations and laboratory analyses showed rapid and systematic changes in pH, alkalinity, and conductance, as well as increases in the aqueous concentrations of trace element species. The geochemical data were first evaluated using principal component analysis (PCA) in order to identify correlations between aqueous species. The PCA findings were then used in formulating a geochemical model to simulate the processes likely to be responsible for the observed increases in the concentrations of dissolved constituents. Modeling was conducted taking into account aqueous and surface complexation, cation exchange, and mineral precipitation and dissolution. Reasonable matches between measured data and model results suggest that: (1) CO2 dissolution in the groundwater causes calcite to dissolve. (2) Observed increases in the concentration of dissolved trace metals result likely from Ca+2-driven ion exchange with clays (smectites) and sorption/desorption reactions likely involving Fe (hydr)oxides. (3) Bicarbonate from CO2 dissolution appears to compete for sorption with anionic species such as HAsO4-2, potentially increasing dissolved As levels in groundwater. ?? 2011 Published by Elsevier Ltd.

Massive CO2 Ice Deposits Sequestered in the South Polar Layered Deposits of Mars

Science.gov (United States)

Phillips, Roger J.; Davis, Brian J.; Tanaka, Kenneth L.; Byrne, Shane; Mellon, Michael T.; Putzig, Nathaniel E.; Haberle, Robert M.; Kahre, Melinda A.; Campbell, Bruce A.; Carter, Lynn M.; Smith, Isaac B.; Holt, John W.; Smrekar, Suzanne E.; Nunes, Daniel C.; Plaut, Jeffrey J.; Egan, Anthony F.; Titus, Timothy N.; Seu, Roberto

2011-01-01

Shallow Radar soundings from the Mars Reconnaissance Orbiter reveal a buried deposit of carbon dioxide (CO2) ice within the south polar layered deposits of Mars with a volume of 9500 to 12,500 cubic kilometers, about 30 times that previously estimated for the south pole residual cap. The deposit occurs within a stratigraphic unit that is uniquely marked by collapse features and other evidence of interior CO2 volatile release. If released into the atmosphere at times of high obliquity, the CO2 reservoir would increase the atmospheric mass by up to 80%, leading to more frequent and intense dust storms and to more regions where liquid water could persist without boiling.

Integration of Magnetic and Geotechnical methods for Shallow Subsurface Soil Characterization at Sungai Batu, Kedah, Malaysia

Science.gov (United States)

Samuel, Y. M.; Saad, R.; Muztaza, N. M.; Saidin, M. M.; Muhammad, S. B.

2018-04-01

Magnetic and geotechnical methods were used for shallow subsurface soil characterization at Sungai Batu, Kedah, (Malaysia). Ground magnetic data were collected along a survey line of length 160 m long at 2 m constant station spacing, while soil drilling using hand auger was conducted at 21 m on the survey line using 0.2 m sampling interval drilled to a depth of 5 m. Result from the processed magnetic profile data shows distribution of magnetic residuals in the range of -4.55 to 1.61 nT, with magnetic low (-4.55 nT to -0.058 nT) and were identified at distances 4 m, 10 to 16 m, 20 to 26 m, 58 m, 82 m, 104 to 106 m, 118 m, and 124 to 140 m. The magnetic lows are attributes of sediments. The result from the soil drilling shows sticky samples with variable sizes, greyish to brownish / reddish in colour, and some of the samples show the presence of shiny and black spots. The characteristics of the samples suggest the soil as a by-product of completely weathered rock; weak with high water content and classified as Grade V soil. The study concludes; integration of geophysical and geotechnical methods aided in characterizing the subsurface soil at Sungai Batu. The result was correlated with previous studies and confirms the importance of integrated approach in minimising ambiguity in interpretation.

Geochemistry of silicate-rich rocks can curtail spreading of carbon dioxide in subsurface aquifers.

Science.gov (United States)

Cardoso, S S S; Andres, J T H

2014-12-11

Pools of carbon dioxide are found in natural geological accumulations and in engineered storage in saline aquifers. It has been thought that once this CO2 dissolves in the formation water, making it denser, convection streams will transport it efficiently to depth, but this may not be so. Here, we assess theoretically and experimentally the impact of natural chemical reactions between the dissolved CO2 and the rock formation on the convection streams in the subsurface. We show that, while in carbonate rocks the streaming of dissolved carbon dioxide persists, the chemical interactions in silicate-rich rocks may curb this transport drastically and even inhibit it altogether. These results challenge our view of carbon sequestration and dissolution rates in the subsurface, suggesting that pooled carbon dioxide may remain in the shallower regions of the formation for hundreds to thousands of years. The deeper regions of the reservoir can remain virtually carbon free.

Hydrogeochemical Impact of CO₂ Leakage from Geological Sequestration on Shallow Potable Aquifers

DEFF Research Database (Denmark)

Cahill, Aaron Graham

. Although considered highly unlikely following appropriate site selection, leakage of CO2 from CCGS forms a major concern for both scientists and the public. Leakage would potentially occur through faults or abandoned boreholes and ultimately result in upward migration and discharge to the atmosphere....... During migration CO2 would dissolve into groundwater forming carbonic acid, induce water-rock reactions and thus change groundwater chemistry. Therefore prior to implementation of this potentially necessary technology, environmental risks associated with leakage must be understood. Over the past 10 years...... it be detected geochemically? Some common hydrochemical development is apparent from the literature however many aspects of hydrogeological and hydrogeochemical impact of leakage into shallow aquifers used in water supply remain unclear. In this Ph.D. study an integrated approach was employed in order to answer...

Impact of CO₂ on the Evolution of Microbial Communities Exposed to Carbon Storage Conditions, Enhanced Oil Recovery, and CO₂ Leakage

Energy Technology Data Exchange (ETDEWEB)

Gulliver, Djuna [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Gregory, Kelvin B. [Carnegie Mellon Univ., Pittsburgh, PA (United States); Lowry, Gregorgy V. [Carnegie Mellon Univ., Pittsburgh, PA (United States)

2016-06-20

Geologic carbon storage (GCS) is a crucial part of a proposed mitigation strategy to reduce the anthropogenic carbon dioxide (CO₂) emissions to the atmosphere. During this process, CO₂ is injected as super critical carbon dioxide (SC-CO₂) in confined deep subsurface storage units, such as saline aquifers and depleted oil reservoirs. The deposition of vast amounts of CO₂ in subsurface geologic formations could unintentionally lead to CO₂ leakage into overlying freshwater aquifers. Introduction of CO₂ into these subsurface environments will greatly increase the CO₂2 concentration and will create CO₂ concentration gradients that drive changes in the microbial communities present. While it is expected that altered microbial communities will impact the biogeochemistry of the subsurface, there is no information available on how CO₂ gradients will impact these communities. The overarching goal of this project is to understand how CO₂ exposure will impact subsurface microbial communities at temperatures and pressures that are relevant to GCS and CO₂ leakage scenarios. To meet this goal, unfiltered, aqueous samples from a deep saline aquifer, a depleted oil reservoir, and a fresh water aquifer were exposed to varied concentrations of CO₂ at reservoir pressure and temperature. The microbial ecology of the samples was examined using molecular, DNA-based techniques. The results from these studies were also compared across the sites to determine any existing trends. Results reveal that increasing CO₂ leads to decreased DNA concentrations regardless of the site, suggesting that microbial processes will be significantly hindered or absent nearest the CO₂ injection/leakage plume where CO₂ concentrations are highest. At CO₂ exposures expected downgradient from the CO₂ plume, selected microorganisms

Impact of CO₂ on the Evolution of Microbial Communities Exposed to Carbon Storage Conditions, Enhanced Oil Recovery, and CO₂ Leakage

Energy Technology Data Exchange (ETDEWEB)

Gulliver, Djuna M. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Gregory, Kelvin B. [Carnegie Mellon Univ., Pittsburgh, PA (United States). Dept. of Civil and Environmental Engineering; Lowry, Gregory V. [Carnegie Mellon Univ., Pittsburgh, PA (United States). Dept. of Civil and Environmental Engineering

2016-06-20

Geologic carbon storage (GCS) is a crucial part of a proposed mitigation strategy to reduce the anthropogenic carbon dioxide (CO₂) emissions to the atmosphere. During this process, CO₂ is injected as super critical carbon dioxide (SC-CO₂) in confined deep subsurface storage units, such as saline aquifers and depleted oil reservoirs. The deposition of vast amounts of CO₂ in subsurface geologic formations could unintentionally lead to CO₂ leakage into overlying freshwater aquifers. Introduction of CO₂ into these subsurface environments will greatly increase the CO₂ concentration and will create CO₂ concentration gradients that drive changes in the microbial communities present. While it is expected that altered microbial communities will impact the biogeochemistry of the subsurface, there is no information available on how CO₂ gradients will impact these communities. The overarching goal of this project is to understand how CO₂ exposure will impact subsurface microbial communities at temperatures and pressures that are relevant to GCS and CO₂ leakage scenarios. To meet this goal, unfiltered, aqueous samples from a deep saline aquifer, a depleted oil reservoir, and a fresh water aquifer were exposed to varied concentrations of CO₂ at reservoir pressure and temperature. The microbial ecology of the samples was examined using molecular, DNA-based techniques. The results from these studies were also compared across the sites to determine any existing trends. Results reveal that increasing CO₂ leads to decreased DNA concentrations regardless of the site, suggesting that microbial processes will be significantly hindered or absent nearest the CO₂ injection/leakage plume where CO₂ concentrations are highest. At CO₂ exposures expected downgradient from the CO₂ plume, selected microorganisms

Biological CO2 conversion to acetate in subsurface coal-sand formation using a high-pressure reactor system

Science.gov (United States)

Ohtomo, Y.; Ijiri, A.; Ikegawa, Y.; Tsutsumi, M.; Imachi, H.; Uramoto, G.; Hoshino, T.; Morono, Y.; Tanikawa, W.; Hirose, T.; Inagaki, F.

2013-12-01

The geological CO2 sequestration into subsurface unmineable oil/gas fields and coal formations has been considered as one of the possible ways to reduce dispersal of anthropogenic greenhouse gasses into the atmosphere. However, feasibility of CO2 injection largely depends on a variety of geological and economical settings, and its ecological consequences have remained largely unpredictable. To address these issues, we developed a new flow-through-type CO2 injection system designated as the 'geobio-reactor system' to examine possible geophysical, geochemical and microbiological impact caused by CO2 injection under in-situ pressure (0-100 MPa) and temperature (0-70°C) conditions. In this study, we investigated Eocene bituminous coal-sandstones in the northwestern Pacific coast, Hokkaido, Japan, using the geobio-reactor system. Anaerobic artificial fluid and CO2 (flow rate: 0.002 and 0.00001 mL/min, respectively) were continuously supplemented into the coal-sand column under the pore pressure of 40 MPa (confined pressure: 41 MPa) at 40°C for 56 days. Molecular analysis of bacterial 16S rRNA genes showed that predominant bacterial components were physically dispersed from coal to sand as the intact form during experiment. Cultivation experiments from sub-sampling fluids indicated that some terrestrial microbes could preserve their survival in subsurface condition. Molecular analysis of archaeal 16S rRNA genes also showed that no methanogens were activated during experiment. We also anaerobically incubated the coal sample using conventional batch-type cultivation technique with a medium for methanogens. After one year of the batch incubation at 20°C, methane could be detected from the cultures except for the acetate-fed culture. The sequence of archaeal 16S rRNA genes via PCR amplification obtained from the H2 plus formate-fed culture was affiliated with a hydrogenotrophic methanogen within the genus Methanobacterium, whereas the methanol plus trimethylamine culture

Jupiter Trojan's Shallow Subsurface: Direct Observation By Radar Sounding

Science.gov (United States)

Herique, A.; Plettemeier, D.; Beck, P.; Michel, P.; Kumamoto, A.; Kofman, W. W.

2017-12-01

Most of the Jupiter's Trojan are classified as spectral type P or D from visible and near-IR observations. Still, major question remain regarding theire origin and geological evolution: What ices are present in their interior, and in what amount? What is the abundance and the nature of the organic fraction? Did they experience some level of differentiation powered by 26Al? Answering theses question is the goal of the Solar-Power Sail JAXA mission [1, 2]. This mission plans to study the surface by remote sensing in the optical in IR domain. This probe will carry a large-sized lander with a drill to sample the constitutive material at meter depth in order to complement physical and chemical properties measured by on-board instruments. The sample return is an option under study.Radar sounding of the shallow subsurface would be envisaged in complement to this payload. Sounding radar could provide the structure of the first tens of meters of the Trojan surface. It will allow identifying layering, ice lens, and embedded block. It also will enable to reconnect the surface with the deep interior in order to identify exogenous / pristine material. For the surface package, the drilling and the sample return, radar sounding is a unique opportunity to support the selection of the landing site and to provide the greater geological context of the samples that will be returned to Earth.In this paper, we will detail the objective of this instrument and then we will outline the proposed instrument, which is inheriting from the radar developed for the AIDA/AIM mission.[1] Mori, O. et al., Science experiments on a Jupiter Trojan Asteroid in the solar powerd sail mission. LPSC 2016 - 1822.[2] Okada, T. et al., Science and Exploration of a Jupiter Trojan Asteroid in the solar-power sail mission. LPSC 2017 - 1828.

Direct Experiments on the Ocean Disposal of Fossil Fuel CO2

Energy Technology Data Exchange (ETDEWEB)

Barry, James, P.

2010-05-26

Funding from DoE grant # FG0204-ER63721, Direct Experiments on the Ocean Disposal of Fossil Fuel CO2, supposed several postdoctoral fellows and research activities at MBARI related to ocean CO2 disposal and the biological consequences of high ocean CO2 levels on marine organisms. Postdocs supported on the project included Brad Seibel, now an associate professor at the University of Rhode Island, Jeff Drazen, now an associate professor at the University of Hawaii, and Eric Pane, who continues as a research associate at MBARI. Thus, the project contributed significantly to the professional development of young scientists. In addition, we made significant progress in several research areas. We continued several deep-sea CO2 release experiments using support from DoE and MBARI, along with several collaborators. These CO2 release studies had the goal of broadening our understanding of the effects of high ocean CO2 levels on deep sea animals in the vicinity of potential release sites for direct deep-ocean carbon dioxide sequestration. Using MBARI ships and ROVs, we performed these experiments at depths of 3000 to 3600 m, where liquid CO2 is heavier than seawater. CO2 was released into small pools (sections of PVC pipe) on the seabed, where it dissolved and drifted downstream, bathing any caged animals and sediments in a CO2-rich, low-pH plume. We assessed the survival of organisms nearby. Several publications arose from these studies (Barry et al. 2004, 2005; Carman et al. 2004; Thistle et al. 2005, 2006, 2007; Fleeger et al. 2006, 2010; Barry and Drazen 2007; Bernhard et al. 2009; Sedlacek et al. 2009; Ricketts et al. in press; Barry et al, in revision) concerning the sensitivity of animals to low pH waters. Using funds from DoE and MBARI, we designed and fabricated a hyperbaric trap-respirometer to study metabolic rates of deep-sea fishes under high CO2 conditions (Drazen et al, 2005), as well as a gas-control aquarium system to support laboratory studies of the

Connexin hemichannel-mediated CO2-dependent release of ATP in the medulla oblongata contributes to central respiratory chemosensitivity

Science.gov (United States)

Huckstepp, Robert T R; id Bihi, Rachid; Eason, Robert; Spyer, K Michael; Dicke, Nikolai; Willecke, Klaus; Marina, Nephtali; Gourine, Alexander V; Dale, Nicholas

2010-01-01

Arterial , a major determinant of breathing, is detected by chemosensors located in the brainstem. These are important for maintaining physiological levels of in the blood and brain, yet the mechanisms by which the brain senses CO2 remain controversial. As ATP release at the ventral surface of the brainstem has been causally linked to the adaptive changes in ventilation in response to hypercapnia, we have studied the mechanisms of CO2-dependent ATP release in slices containing the ventral surface of the medulla oblongata. We found that CO2-dependent ATP release occurs in the absence of extracellular acidification and correlates directly with the level of . ATP release is independent of extracellular Ca2+ and may occur via the opening of a gap junction hemichannel. As agents that act on connexin channels block this release, but compounds selective for pannexin-1 have no effect, we conclude that a connexin hemichannel is involved in CO2-dependent ATP release. We have used molecular, genetic and immunocytochemical techniques to demonstrate that in the medulla oblongata connexin 26 (Cx26) is preferentially expressed near the ventral surface. The leptomeninges, subpial astrocytes and astrocytes ensheathing penetrating blood vessels at the ventral surface of the medulla can be loaded with dye in a CO2-dependent manner, suggesting that gating of a hemichannel is involved in ATP release. This distribution of CO2-dependent dye loading closely mirrors that of Cx26 expression and colocalizes to glial fibrillary acidic protein (GFAP)-positive cells. In vivo, blockers with selectivity for Cx26 reduce hypercapnia-evoked ATP release and the consequent adaptive enhancement of breathing. We therefore propose that Cx26-mediated release of ATP in response to changes in is an important mechanism contributing to central respiratory chemosensitivity. PMID:20736421

Impact of elevated CO_2 concentrations on carbonate mineral precipitation ability of sulfate-reducing bacteria and implications for CO_2 sequestration

International Nuclear Information System (INIS)

Paul, Varun G.; Wronkiewicz, David J.; Mormile, Melanie R.

2017-01-01

Interest in anthropogenic CO_2 release and associated global climatic change has prompted numerous laboratory-scale and commercial efforts focused on capturing, sequestering or utilizing CO_2 in the subsurface. Known carbonate mineral precipitating microorganisms, such as the anaerobic sulfate-reducing bacteria (SRB), could enhance the rate of conversion of CO_2 into solid minerals and thereby improve long-term storage of captured gasses. The ability of SRB to induce carbonate mineral precipitation, when exposed to atmospheric and elevated pCO_2, was investigated in laboratory scale tests with bacteria from organic-rich sediments collected from hypersaline Lake Estancia, New Mexico. The enriched SRB culture was inoculated in continuous gas flow and batch reactors under variable headspace pCO_2 (0.0059 psi to 20 psi). Solution pH, redox conditions, sulfide, calcium and magnesium concentrations were monitored in the reactors. Those reactors containing SRB that were exposed to pCO_2 of 14.7 psi or less showed Mg-calcite precipitation. Reactors exposed to 20 psi pCO_2 did not exhibit any carbonate mineralization, likely due to the inhibition of bacterial metabolism caused by the high levels of CO_2. Hydrogen, lactate and formate served as suitable electron donors for the SRB metabolism and related carbonate mineralization. Carbon isotopic studies confirmed that ∼53% of carbon in the precipitated carbonate minerals was derived from the CO_2 headspace, with the remaining carbon being derived from the organic electron donors, and the bicarbonate ions available in the liquid medium. The ability of halotolerant SRB to induce the precipitation of carbonate minerals can potentially be applied to the long-term storage of anthropogenic CO_2 in saline aquifers and other ideal subsurface rock units by converting the gas into solid immobile phases. - Highlights: • SRB under study are capable of precipitating calcite up to 14.7 psi pCO_2. • At 20 psi pCO_2, bacterial activity

Rates of CO2 Mineralization in Geological Carbon Storage.

Science.gov (United States)

Zhang, Shuo; DePaolo, Donald J

2017-09-19

Geologic carbon storage (GCS) involves capture and purification of CO 2 at industrial emission sources, compression into a supercritical state, and subsequent injection into geologic formations. This process reverses the flow of carbon to the atmosphere with the intention of returning the carbon to long-term geologic storage. Models suggest that most of the injected CO 2 will be "trapped" in the subsurface by physical means, but the most risk-free and permanent form of carbon storage is as carbonate minerals (Ca,Mg,Fe)CO 3 . The transformation of CO 2 to carbonate minerals requires supply of the necessary divalent cations by dissolution of silicate minerals. Available data suggest that rates of transformation are highly uncertain and difficult to predict by standard approaches. Here we show that the chemical kinetic observations and experimental results, when they can be reduced to a single cation-release time scale that describes the fractional rate at which cations are released to solution by mineral dissolution, show sufficiently systematic behavior as a function of pH, fluid flow rate, and time that the rates of mineralization can be estimated with reasonable certainty. The rate of mineralization depends on both the abundance (determined by the reservoir rock mineralogy) and the rate at which cations are released from silicate minerals by dissolution into pore fluid that has been acidified with dissolved CO 2 . Laboratory-measured rates and field observations give values spanning 8 to 10 orders of magnitude, but when they are evaluated in the context of a reservoir-scale reactive transport simulation, this range becomes much smaller. The reservoir scale simulations provide limits on the applicable conditions under which silicate mineral dissolution and subsequent carbonate mineral precipitation are likely to occur (pH 4.5 to 6, fluid flow velocity less than 5 m/year, and 50-100 years or more after the start of injection). These constraints lead to estimates of

Microbial controls on metal mobility under the low nutrient fluxes found throughout the subsurface

International Nuclear Information System (INIS)

Boult, Stephen; Hand, Victoria L.; Vaughan, David J.

2006-01-01

Laboratory simulations and field studies of the shallow subsurface have shown that microbes and their extracellular products can influence the mobility of toxic metals from waste disposal sites. Modelling the transport of contaminants in groundwater may, therefore, require the input of microbial ecology data in addition to geochemical data, thus increasing the costs and the uncertainty of predictions. However, whether microbial effects on contaminant mobility occur extensively in the natural subsurface is unknown because the conditions under which they have been observed hitherto are generally unrepresentative of the average subsurface environment. Here, we show that microbial activity affects the mobility of a toxic trace metal (Cu) under the relatively low nutrient fluxes that dominate subsurface systems. More particularly, we show that under these low nutrient conditions, microbes and microbial products can immobilize metal but may themselves be subject to subsequent mobilization, thus complicating the pattern of metal storage and release. Our results show that the capability of microbes in the subsurface to change both the capacity of porous media to store metal, and the behaviour of metal that is released, is not restricted to the well researched environments close to sites of waste disposal. We anticipate our simulations will be a starting point for generating input data for transport models, and specifying the mechanism of metal remobilisation in environments more representative of the subsurface generally

Heterogeneity-enhanced gas phase formation in shallow aquifers during leakage of CO2-saturated water from geologic sequestration sites

DEFF Research Database (Denmark)

Plampin, Michael R.; Lassen, Rune Nørbæk; Sakaki, Toshihiro

2014-01-01

sands. Soil moisture sensors were utilized to observe the formation of gas phase near the porous media interfaces. Results indicate that the conditions under which heterogeneity controls gas phase evolution can be successfully predicted through analysis of simple parameters, including the dissolved CO2......, it is important to understand the physical processes that CO2 will undergo as it moves through naturally heterogeneous porous media formations. Previous studies have shown that heterogeneity can enhance the evolution of gas phase CO2 in some cases, but the conditions under which this occurs have not yet been...... quantitatively defined, nor tested through laboratory experiments. This study quantitatively investigates the effects of geologic heterogeneity on the process of gas phase CO2 evolution in shallow aquifers through an extensive set of experiments conducted in a column that was packed with layers of various test...

Release of Dissolved CO2 from Water in Laboratory Porous Media Following Rapid Depressurization

Science.gov (United States)

Crews, J. B.; Cooper, C. A.

2011-12-01

A bench-top laboratory study is undertaken to investigate the effects of seismic shocks on brine aquifers into which carbon dioxide has been injected for permanent storage. Long-term storage in deep saline aquifers has been proposed and studied as one of the most viable near-term options for sequestering fossil fuel-derived carbon dioxide from the atmosphere to curb anthropogenic climate change. Upon injection into the subsurface, it is expected that CO2, as either a gas or supercritical fluid, will mix convectively with the formation water. The possibility exists, however, that dissolved CO2 will come out of solution as a result of an earthquake. The effect is similar to that of slamming an unsealed container of carbonated beverage on a table; previously dissolved CO2 precipitates, forms bubbles, and rises due to buoyancy. In this study, we measure the change in gas-phase CO2 concentration as a function of the magnitude of the shock and the initial concentration of CO2. In addition, we investigate and seek to characterize the nucleation and transport of CO2 bubbles in a porous medium after a seismic shock. Experiments are conducted using a Hele-Shaw cell and a CCD camera to quantify the fraction of dissolved CO2 that comes out of solution as a result of a sharp mechanical impulse. The data are used to identify and constrain the conditions under which CO2 comes out of solution and, further, to understand the end-behavior of the precipitated gas-phase CO2 as it moves through or is immobilized in a porous medium.

Emulsion-based encapsulation and delivery of nanoparticles for the controlled release of alkalinity within the subsurface environment

Science.gov (United States)

Ramsburg, C. A.; Muller, K.; Gill, J.

2012-12-01

Many current approaches to managing groundwater contamination rely on further advances in amendment delivery in order to initiate and sustain contaminant degradation or immobilization. In fact, limited or ineffective delivery is often cited when treatment objectives are not attained. Emulsions, specifically oil-in-water emulsions, have demonstrated potential to aid delivery of remediation amendments. Emulsions also afford opportunities to control the release of active ingredients encapsulated within the droplets. Our research is currently focused on the controlled release of nanoparticle-based buffering agents using oil-in-water emulsions. This interest is motivated by the fact that chemical and biological processes employed for the remediation and stewardship of contaminated sites often necessitate control of pH during treatment and, in some cases, long thereafter. Alkalinity-release nanoparticles (e.g., CaCO3, MgO) were suspended within soybean oil and subsequently encapsulated by through the creation of oil-in-water emulsions. These oil-in-water emulsions are designed to have physical properties which are favorable for subsurface delivery (nominal properties: 1 g/mL density; 10 cP viscosity; and 1.5 μm droplet diameter). Buffer capacity titrations suggest that MgO particles are moderately more accessible within the oil phase and nearly twice as effective (on a per mass basis) at releasing alkalinity (as compared to the CaCO3 particles). Results from experiments designed to assess the release kinetics suggest that a linear driving force model is capable of describing the release process and mass transfer coefficients are constant through the reactive life of the emulsion. The release kinetics in emulsions containing MgO particles were found to be three orders of magnitude faster than those quantified for emulsions containing CaCO3. The slower release kinetics of the emulsions containing CaCO3 particles may prove beneficial when considering pH control at sites

Burrows of the Semi-Terrestrial Crab Ucides cordatus Enhance CO2 Release in a North Brazilian Mangrove Forest

Science.gov (United States)

Pülmanns, Nathalie; Diele, Karen; Mehlig, Ulf; Nordhaus, Inga

2014-01-01

Ucides cordatus is an abundant mangrove crab in Brazil constructing burrows of up to 2 m depth. Sediment around burrows may oxidize during low tides. This increase in sediment-air contact area may enhance carbon degradation processes. We hypothesized that 1) the sediment CO2 efflux rate is greater with burrows than without and 2) the reduction potential in radial profiles in the sediment surrounding the burrows decreases gradually, until approximating non-bioturbated conditions. Sampling was conducted during the North Brazilian wet season at neap tides. CO2 efflux rates of inhabited burrows and plain sediment were measured with a CO2/H2O gas analyzer connected to a respiration chamber. Sediment redox potential, pH and temperature were measured in the sediment surrounding the burrows at horizontal distances of 2, 5, 8 and 15 cm at four sediment depths (1, 10, 30 and 50 cm) and rH values were calculated. Sediment cores (50 cm length) were taken to measure the same parameters for plain sediment. CO2 efflux rates of plain sediment and individual crab burrows with entrance diameters of 7 cm were 0.7–1.3 µmol m−2 s−1 and 0.2–0.4 µmol burrows−1 s−1, respectively. CO2 released from a Rhizophora mangle dominated forest with an average of 1.7 U. cordatus burrows−1 m−2 yielded 1.0–1.7 µmol m−2 s−1, depending on the month and burrow entrance diameter. Laboratory experiments revealed that 20–60% of the CO2 released by burrows originated from crab respiration. Temporal changes in the reduction potential in the sediment surrounding the burrows did not influence the CO2 release from burrows. More oxidized conditions of plain sediment over time may explain the increase in CO2 release until the end of the wet season. CO2 released by U. cordatus and their burrows may be a significant pathway of CO2 export from mangrove sediments and should be considered in mangrove carbon budget estimates. PMID:25313661

Burrows of the semi-terrestrial crab Ucides cordatus enhance CO2 release in a North Brazilian mangrove forest.

Directory of Open Access Journals (Sweden)

Nathalie Pülmanns

Full Text Available Ucides cordatus is an abundant mangrove crab in Brazil constructing burrows of up to 2 m depth. Sediment around burrows may oxidize during low tides. This increase in sediment-air contact area may enhance carbon degradation processes. We hypothesized that 1 the sediment CO2 efflux rate is greater with burrows than without and 2 the reduction potential in radial profiles in the sediment surrounding the burrows decreases gradually, until approximating non-bioturbated conditions. Sampling was conducted during the North Brazilian wet season at neap tides. CO2 efflux rates of inhabited burrows and plain sediment were measured with a CO2/H2O gas analyzer connected to a respiration chamber. Sediment redox potential, pH and temperature were measured in the sediment surrounding the burrows at horizontal distances of 2, 5, 8 and 15 cm at four sediment depths (1, 10, 30 and 50 cm and rH values were calculated. Sediment cores (50 cm length were taken to measure the same parameters for plain sediment. CO2 efflux rates of plain sediment and individual crab burrows with entrance diameters of 7 cm were 0.7-1.3 µmol m(-2 s(-1 and 0.2-0.4 µmol burrows(-1 s(-1, respectively. CO2 released from a Rhizophora mangle dominated forest with an average of 1.7 U. cordatus burrows(-1 m(-2 yielded 1.0-1.7 µmol m(-2 s(-1, depending on the month and burrow entrance diameter. Laboratory experiments revealed that 20-60% of the CO2 released by burrows originated from crab respiration. Temporal changes in the reduction potential in the sediment surrounding the burrows did not influence the CO2 release from burrows. More oxidized conditions of plain sediment over time may explain the increase in CO2 release until the end of the wet season. CO2 released by U. cordatus and their burrows may be a significant pathway of CO2 export from mangrove sediments and should be considered in mangrove carbon budget estimates.

Burrows of the semi-terrestrial crab Ucides cordatus enhance CO2 release in a North Brazilian mangrove forest.

Science.gov (United States)

Pülmanns, Nathalie; Diele, Karen; Mehlig, Ulf; Nordhaus, Inga

2014-01-01

Ucides cordatus is an abundant mangrove crab in Brazil constructing burrows of up to 2 m depth. Sediment around burrows may oxidize during low tides. This increase in sediment-air contact area may enhance carbon degradation processes. We hypothesized that 1) the sediment CO2 efflux rate is greater with burrows than without and 2) the reduction potential in radial profiles in the sediment surrounding the burrows decreases gradually, until approximating non-bioturbated conditions. Sampling was conducted during the North Brazilian wet season at neap tides. CO2 efflux rates of inhabited burrows and plain sediment were measured with a CO2/H2O gas analyzer connected to a respiration chamber. Sediment redox potential, pH and temperature were measured in the sediment surrounding the burrows at horizontal distances of 2, 5, 8 and 15 cm at four sediment depths (1, 10, 30 and 50 cm) and rH values were calculated. Sediment cores (50 cm length) were taken to measure the same parameters for plain sediment. CO2 efflux rates of plain sediment and individual crab burrows with entrance diameters of 7 cm were 0.7-1.3 µmol m(-2) s(-1) and 0.2-0.4 µmol burrows(-1) s(-1), respectively. CO2 released from a Rhizophora mangle dominated forest with an average of 1.7 U. cordatus burrows(-1) m(-2) yielded 1.0-1.7 µmol m(-2) s(-1), depending on the month and burrow entrance diameter. Laboratory experiments revealed that 20-60% of the CO2 released by burrows originated from crab respiration. Temporal changes in the reduction potential in the sediment surrounding the burrows did not influence the CO2 release from burrows. More oxidized conditions of plain sediment over time may explain the increase in CO2 release until the end of the wet season. CO2 released by U. cordatus and their burrows may be a significant pathway of CO2 export from mangrove sediments and should be considered in mangrove carbon budget estimates.

Subsurface Water as Natural CO{sub 2} Sink

Energy Technology Data Exchange (ETDEWEB)

Gillon, M. [Centre National de la Recherche Scientifique (UMR CNRS 8148-IDES), Interaction et Dynamique des Environnements de Surface, Universite Paris 11 and Centre National de la Recherche Scientifique (UMR UAPV-INRA EMMAH), Environnement Mediterraneen et Modelisation des Agro-Hydrosystemes, Universite d' Avignon et des Pays de Vaucluse, Avignon, (France); Barbecot, F.; Gibert, E.; Massault, M. [Centre National de La Recherche Scientifique (UMR CNRS 8148-IDES), Interaction et Dynamique des Environnements de Surface, Universite Paris 11 (France)

2013-07-15

In aquifer recharge areas, groundwater mineralization acts as an important sink for CO{sub 2} (assessed at 100 Mt{sub co2}/a on a European scale). An isotopic study of C fluxes in the unsaturated zone of a sand carbonate aquifer shows that the physical and geochemical processes controlling CO{sub 2} abstraction induce changes in the isotopic composition of both dissolved and matrix carbonates. An integrated record of these fluxes toward the aquifers is evidenced through isotopic investigation of the recharge areas. It is evidenced that the unsaturated zone represents an archive of pristine conditions, and would help to quantify downward C fluxes and environmental changes related to this CO{sub 2} abstraction process. (author)

Thermal release of D2 from new Be-D co-deposits on previously baked co-deposits

Science.gov (United States)

Baldwin, M. J.; Doerner, R. P.

2015-12-01

Past experiments and modeling with the TMAP code in [1, 2] indicated that Be-D co-deposited layers are less (time-wise) efficiently desorbed of retained D in a fixed low-temperature bake, as the layer grows in thickness. In ITER, beryllium rich co-deposited layers will grow in thickness over the life of the machine. Although, compared with the analyses in [1, 2], ITER presents a slightly different bake efficiency problem because of instances of prior tritium recover/control baking. More relevant to ITER, is the thermal release from a new and saturated co-deposit layer in contact with a thickness of previously-baked, less-saturated, co-deposit. Experiments that examine the desorption of saturated co-deposited over-layers in contact with previously baked under-layers are reported and comparison is made to layers of the same combined thickness. Deposition temperatures of ∼323 K and ∼373 K are explored. It is found that an instance of prior bake leads to a subtle effect on the under-layer. The effect causes the thermal desorption of the new saturated over-layer to deviate from the prediction of the validated TMAP model in [2]. Instead of the D thermal release reflecting the combined thickness and levels of D saturation in the over and under layer, experiment differs in that, i) the desorption is a fractional superposition of desorption from the saturated over-layer, with ii) that of the combined over and under -layer thickness. The result is not easily modeled by TMAP without the incorporation of a thin BeO inter-layer which is confirmed experimentally on baked Be-D co-deposits using X-ray micro-analysis.

Thermal release of D_2 from new Be-D co-deposits on previously baked co-deposits

International Nuclear Information System (INIS)

Baldwin, M.J.; Doerner, R.P.

2015-01-01

Past experiments and modeling with the TMAP code in [1, 2] indicated that Be-D co-deposited layers are less (time-wise) efficiently desorbed of retained D in a fixed low-temperature bake, as the layer grows in thickness. In ITER, beryllium rich co-deposited layers will grow in thickness over the life of the machine. Although, compared with the analyses in [1, 2], ITER presents a slightly different bake efficiency problem because of instances of prior tritium recover/control baking. More relevant to ITER, is the thermal release from a new and saturated co-deposit layer in contact with a thickness of previously-baked, less-saturated, co-deposit. Experiments that examine the desorption of saturated co-deposited over-layers in contact with previously baked under-layers are reported and comparison is made to layers of the same combined thickness. Deposition temperatures of ∼323 K and ∼373 K are explored. It is found that an instance of prior bake leads to a subtle effect on the under-layer. The effect causes the thermal desorption of the new saturated over-layer to deviate from the prediction of the validated TMAP model in [2]. Instead of the D thermal release reflecting the combined thickness and levels of D saturation in the over and under layer, experiment differs in that, i) the desorption is a fractional superposition of desorption from the saturated over-layer, with ii) that of the combined over and under -layer thickness. The result is not easily modeled by TMAP without the incorporation of a thin BeO inter-layer which is confirmed experimentally on baked Be-D co-deposits using X-ray micro-analysis.

Under-expanded jets and dispersion in supercritical CO_2 releases from a large-scale pipeline

International Nuclear Information System (INIS)

Guo, Xiaolu; Yan, Xingqing; Yu, Jianliang; Zhang, Yongchun; Chen, Shaoyun; Mahgerefteh, Haroun; Martynov, Sergey; Collard, Alexander; Proust, Christophe

2016-01-01

Highlights: • A large-scale full instrumented CO_2 test pipeline (258 m long, 233 mm id) has been developed. • The dynamic pressure evolutions near the orifice were recorded with differential pressure transducers. • The highly under-expanded jet flow structure in the near-field was studied in supercritical leakage. • The formation of the visible cloud, the distributions of temperature and concentration in the far-field were analysed. - Abstract: Long-distance CO_2 pipelines will be widely applied to transport captured CO_2 from fossil fuel fired power plants for subsequent sequestration. In the event of pipeline failure a large mass of the inventory may be discharged within a short time, this represents a significant hazard if leaks continue undetected. An important result of the risk assessment for a CO_2 pipeline is the safety distance. At present the lack of knowledge concerning near-field source terms and the far-field dispersion behavior of CO_2 leaking from pipelines can make the calculation of safety distances imprecise. Study of near-field source terms and dispersion behavior is therefore necessary and of paramount importance for assessing safety distances and the impact of CO_2 pipeline releases on the surrounding environment. In order to study CO_2 pipeline leakage, a large-scale pipeline set-up with a total length of 258 m and an internal diameter of 233 mm was constructed to study the near-field characteristics and dispersion behavior of supercritical CO_2 during sudden releases. The dynamic pressure near the orifice and CO_2 concentrations and temperatures within the downstream dispersion region were measured together with the pressures inside the pipeline. The under-expanded jet flow structure and phase transitions in the near-field were studied for supercritical CO_2 released though different orifice diameters (15 mm, 50 mm and Full Bore Rupture). The formation of the visible cloud, the distribution of cloud temperatures and CO_2

First estimates of the contribution of CaCO3 precipitation to the release of CO2 to the atmosphere during young sea ice growth

Science.gov (United States)

Geilfus, N.-X.; Carnat, G.; Dieckmann, G. S.; Halden, N.; Nehrke, G.; Papakyriakou, T.; Tison, J.-L.; Delille, B.

2013-01-01

report measurements of pH, total alkalinity, air-ice CO2 fluxes (chamber method), and CaCO3 content of frost flowers (FF) and thin landfast sea ice. As the temperature decreases, concentration of solutes in the brine skim increases. Along this gradual concentration process, some salts reach their solubility threshold and start precipitating. The precipitation of ikaite (CaCO3.6H2O) was confirmed in the FF and throughout the ice by Raman spectroscopy and X-ray analysis. The amount of ikaite precipitated was estimated to be 25 µmol kg-1 melted FF, in the FF and is shown to decrease from 19 to 15 µmol kg-1 melted ice in the upper part and at the bottom of the ice, respectively. CO2 release due to precipitation of CaCO3 is estimated to be 50 µmol kg-1 melted samples. The dissolved inorganic carbon (DIC) normalized to a salinity of 10 exhibits significant depletion in the upper layer of the ice and in the FF. This DIC loss is estimated to be 2069 µmol kg-1 melted sample and corresponds to a CO2 release from the ice to the atmosphere ranging from 20 to 40 mmol m-2 d-1. This estimate is consistent with flux measurements of air-ice CO2 exchange. Our measurements confirm previous laboratory findings that growing young sea ice acts as a source of CO2 to the atmosphere. CaCO3 precipitation during early ice growth appears to promote the release of CO2 to the atmosphere; however, its contribution to the overall release by newly formed ice is most likely minor.

Risk Assessment and Management for Long-Term Storage of CO2 in Geologic Formations — United States Department of Energy R&D

Directory of Open Access Journals (Sweden)

Dawn Deel

2007-02-01

Full Text Available Concern about increasing atmospheric concentrations of carbon dioxide (CO2 and other greenhouse gases (GHG and their impact on the earth's climate has grown significantly over the last decade. Many countries, including the United States, wrestle with balancing economic development and meeting critical near-term environmental goals while minimizing long-term environmental risks. One promising solution to the buildup of GHGs in the atmosphere, being pursued by the U.S. Department of Energy's (DOE National Energy Technology Laboratory (NETL and its industrial and academic partners, is carbon sequestration—a process of permanent storage of CO2 emissions in underground geologic formations, thus avoiding CO2 release to the atmosphere. This option looks particularly attractive for point source emissions of GHGs, such as fossil fuel fired power plants. CO2 would be captured, transported to a sequestration site, and injected into an appropriate geologic formation. However, sequestration in geologic formations cannot achieve a significant role in reducing GHG emissions unless it is acceptable to stakeholders, regulators, and the general public, i.e., unless the risks involved are judged to be acceptable. One tool that can be used to achieve acceptance of geologic sequestration of CO2 is risk assessment, which is a proven method to objectively manage hazards in facilities such as oil and natural gas fields, pipelines, refineries, and chemical plants. Although probabilistic risk assessment (PRA has been applied in many areas, its application to geologic CO2 sequestration is still in its infancy. The most significant risk from geologic carbon sequestration is leakage of CO2. Two types of CO2 releases are possible—atmospheric and subsurface. High concentrations of CO2 caused by a release to the atmosphere would pose health risks to humans and animals, and any leakage of CO2 back into the atmosphere negates the effort expended to sequester the CO2

TOUGH2Biot - A simulator for coupled thermal-hydrodynamic-mechanical processes in subsurface flow systems: Application to CO2 geological storage and geothermal development

Science.gov (United States)

Lei, Hongwu; Xu, Tianfu; Jin, Guangrong

2015-04-01

Coupled thermal-hydrodynamic-mechanical processes have become increasingly important in studying the issues affecting subsurface flow systems, such as CO2 sequestration in deep saline aquifers and geothermal development. In this study, a mechanical module based on the extended Biot consolidation model was developed and incorporated into the well-established thermal-hydrodynamic simulator TOUGH2, resulting in an integrated numerical THM simulation program TOUGH2Biot. A finite element method was employed to discretize space for rock mechanical calculation and the Mohr-Coulomb failure criterion was used to determine if the rock undergoes shear-slip failure. Mechanics is partly coupled with the thermal-hydrodynamic processes and gives feedback to flow through stress-dependent porosity and permeability. TOUGH2Biot was verified against analytical solutions for the 1D Terzaghi consolidation and cooling-induced subsidence. TOUGH2Biot was applied to evaluate the thermal, hydrodynamic, and mechanical responses of CO2 geological sequestration at the Ordos CCS Demonstration Project, China and geothermal exploitation at the Geysers geothermal field, California. The results demonstrate that TOUGH2Biot is capable of analyzing change in pressure and temperature, displacement, stress, and potential shear-slip failure caused by large scale underground man-made activity in subsurface flow systems. TOUGH2Biot can also be easily extended for complex coupled process problems in fractured media and be conveniently updated to parallel versions on different platforms to take advantage of high-performance computing.

Impact production of CO2 by the Cretaceous/Tertiary extinction bolide and the resultant heating of the earth

Science.gov (United States)

O'Keefe, John D.; Ahrens, Thomas J.

1989-01-01

Various observations and data demonstrate that sea level at the end of the Cretaceous was 150-200 m higher than at present, suggesting the possibility that the extinction bolide struck a shallow marine carbonate-rich sedimentary section. It is shown here that the impact of such a bolide (about 5 km in radius) onto a carbonate-rich terrane would increase the CO2 content of the atmosphere by a factor of two to ten. Additional dissolution of CO2 from the ocean's photic zone could release much larger quantities of CO2. The impact-induced release of CO2, by itself, would enhance atmospheric greenhouse heating and give rise to a worldwide increase in temperature from 2 K to 10 K for periods of 10,000 to 100,000 years.

Evaluation of options relative to the fixation and disposal of 14C-contaminated CO2 as CaCO3

International Nuclear Information System (INIS)

Croff, A.G.

1976-04-01

A paper study was conducted to determine the best method for fixing the 14 C-contaminated CO 2 resulting from an HTGR fuel block burner as CaCO 3 , and to determine the best methods for disposing of the CaCO 3 thus produced. The fixation method selected was the direct reaction of a Ca(OH) 2 slurry with the CO 2 . The least expensive disposal options which are likely to be acceptable appear to be the shallow-land burial of either drummed CaCO 3 solid (total cost = $18.47/kg heavy metal) or drummed CaCO 3 concreted with cement (total cost = $43.33/kg heavy metal). Neither placing the CO 2 fixation process before the Kr removal process nor separating the bulk of the graphite fuel block from the fuel particles is attractive on both technical and economic grounds. However, reduction of the HTGR fuel nitrogen content appears to be a more attractive method of reducing the 14 C release rate

Three Dimensional Seismic Tomography of the Shallow Subsurface Structure Under the Meihua Lake in Ilan, Northeastern Taiwan

Science.gov (United States)

Shih, R.

2008-12-01

The island of Taiwan is located at an ongoing collision boundary between two plates. The Philippine Sea plate and the Eurasian plate collided at the Longitudinal Valley of eastern Taiwan, and the Philippine Sea plate subducted northward beneath the Eurasian plate along the Ryukyu trench in eastern Taiwan at the Hualien area. Further northward in the island, the opening Okinawa trough ended at the Ilan area in northeastern Taiwan. The Ilan area is over populated and potentially able to produce large earthquake; however, since that are is densely covered with forests, due to lack of geologic and geomorphologic evidences, known active faults are still unclear. Recently, a series of topographic offsets of several meters distributed in a zone were found by using the LiDAR DTM data, indicating active normal faulting was activated in the past. Besides, several small sag ponds were mapped to support the active normal faulting activities. Later on, core borings in one of the small ponds (the Meihua Lake, diameter of about 700m) were conducted and the records showed obvious difference of depths in the adjacent boreholes at a very short distance. In order to realize the variation of the distribution of sediments under the Meihua Lake, we conducted a 3d seismic tomography survey at the lake, hopefully to help to verify the faults. In this paper, we will show results of using a 120-channel shallow seismic recording system for mapping the shallow subsurface structure of sediments under the Meihua Lake. During the experiment, we deployed the geophone groups of three geophones at every 6m along the bank of the lake and fired the shots at every 80m around the lake. An impactor of energy 2200 joule per shot was used as a seismic source. We stacked the energy at each shot point around 60 times for receiving clear signals. Since the total extension of recording system is 720m, about one third of the perimeter around the lake, 2,200m, we moved the geophone deployments 3 times to

CO2 Huff-n-Puff process in a light oil shallow shelf carbonate reservoir. Annual report, January 1, 1995--December 31, 1995

Energy Technology Data Exchange (ETDEWEB)

Wehner, S.C.; Boomer, R.J.; Cole, R.; Preiditus, J.; Vogt, J.

1996-09-01

The application of cyclic CO{sub 2}, often referred to as the CO{sub 2} Huff-n-Puff process, may find its niche in the maturing waterfloods of the Permian Basin. Coupling the CO{sub 2} H-n-P process to miscible flooding applications could provide the needed revenue to sufficiently mitigate near-term negative cash flow concerns in the capital intensive miscible projects. Texaco Exploration & Production Inc. and the U.S. Department of Energy have teamed up in an attempt to develop the CO{sub 2} Huff-n-Puff process in the Grayburg/San Andres formation; a light oil, shallow shelf carbonate reservoir within the Permian Basin. This cost-shared effort is intended to demonstrate the viability of this underutilized technology in a specific class of domestic reservoir. A significant amount of oil reserves are located in carbonate reservoirs. Specifically, the carbonates deposited in shallow shelf (SSC) environments make up the largest percentage of known reservoirs within the Permian Basin of North America. Many of these known resources have been under waterflooding operations for decades and are at risk of abandonment if crude oil recoveries cannot be economically enhanced. The selected site for this demonstration project is the Central Vacuum Unit waterflood in Lea County, New Mexico.

Workshop 14: CCS-CO{sub 2}; Atelier 14: CCS-CO{sub 2} (CO{sub 2} Capture and Sequestration)

Energy Technology Data Exchange (ETDEWEB)

Botte, J.M.

2012-07-01

Here are given summaries of the speeches concerning the methodology of the subsurface risk analysis, the carbon management in an industrial basin and the experiment of the Total Rousse firm: the CO{sub 2} storage in an onshore depleted field. (O.M.)

Determining the age of CO2 Released From Mountain Birch Forest and Heath in Arctic Sweden

Science.gov (United States)

Hartley, I. P.; Garnett, M. H.; Hopkins, D. W.; Sommerkorn, M.; Wookey, P. A.

2008-12-01

Nuclear weapons testing released a large amount of 14C into the atmosphere during the mid 20th Century. This radiocarbon pulse provides a tracer that can be used to determine the age of C released from plants and soils. Such information is critical for predicting how terrestrial C storage will respond to global change. If respired CO2 is mainly modern, then respiration and photosynthesis are tightly coupled. In contrast, if older C is being mineralized then there is more potential for climate change to induce C loss. We carried out one of the first studies to measure seasonal variations in the 14C content of CO2 released from arctic ecosystems. Using molecular sieves, we trapped CO2 respired from a mountain birch forest and heath near Abisko, northern Sweden and measured 14C contents by accelerator mass spectrometry. CO2 was collected from both vegetated plots (control) and clipped and trenched plots (CT) on three occasions during the 2007 growing season. In addition, we used a new passive sampling technique to collect CO2 from the CT plots during winter 2007-2008. Assuming that the respired C was derived from post bomb sources (justifiable as the majority of each soil profile was enriched with bomb C), we estimated the age of the CO2 and how it changed during the year in response to changes in plant activity and key environmental drivers. On the heath, the mean age of the CO2 respired from the control plots increased from 4 to 6 years old during the growing season. The CO2 respired from the CT plots increased from 5 years old in early June to 11 years old by July, but then declined to 8 years old in September. The C released during winter was also 8 years old. In the Birch forest, the mean age of CO2 respired from the CT plots increased from 4 years old in late May to 8-9 years old during July and September. However, during winter, the CO2 released was >10 years old. In the control plots, the age of respired CO2 increased from being 1 year old in late May to 6

Isotopic identification of the source of methane in subsurface sediments of an area surrounded by waste disposal facilities

International Nuclear Information System (INIS)

Hackley, K.C.; Liu, C.L.; Trainor, D.

1999-01-01

The major source of methane (CH 4 ) in subsurface sediments on the property of a former hazardous waste treatment facility was determined using isotopic analyses measured on CH 4 and associated groundwater. The site, located on an earthen pier built into a shallow wetland lake, has had a history of waste disposal practices and is surrounded by landfills and other waste management facilities. Concentrations of CH 4 up to 70% were found in the headspace gases of several piezometers screened at 3 different depths (ranging from 8 to 17 m) in lacustrine and glacial till deposits. Possible sources of the CH 4 included a nearby landfill, organic wastes from previous impoundments and microbial gas derived from natural organic matter in the sediments.Isotopic analyses included δ 13 C, δD, 14 C, and 3 H on select CH 4 samples and δD and δ 18 O on groundwater samples. Methane from the deepest glacial till and intermediate lacustrine deposits had δ 13 C values from -79 to -82per thousand, typical of natural 'drift gas' generated by microbial CO 2 -reduction. The CH 4 from the shallow lacustrine deposits had δ 13 C values from -63 to -76per thousand, interpreted as a mixture between CH 4 generated by microbial fermentation and the CO 2 -reduction processes within the subsurface sediments. The δD values of all the CH 4 samples were quite negative ranging from -272 to -299per thousand. Groundwater sampled from the deeper zones also showed quite negative δD values that explained the light δD observed for the CH 4 . Radiocarbon analyses of the CH 4 showed decreasing 14 C activity with depth, from a high of 58 pMC in the shallow sediments to 2 pMC in the deeper glacial till. The isotopic data indicated the majority of CH 4 detected in the till deposits of this site was microbial CH 4 generated from naturally buried organic matter within the subsurface sediments. However, the isotopic data of CH 4 from the shallow piezometers was more variable and the possibility of some

Isotopic identification of the source of methane in subsurface sediments of an area surrounded by waste disposal facilities

Science.gov (United States)

Hackley, Keith C.; Liu, Chao-Li; Trainor, D.

1999-01-01

The major source of methane (CH4) in subsurface sediments on the property of a former hazardous waste treatment facility was determined using isotopic analyses measured on CH4 and associated groundwater. The site, located on an earthen pier built into a shallow wetland lake, has had a history of waste disposal practices and is surrounded by landfills and other waste management facilities. Concentrations of CH4 up to 70% were found in the headspace gases of several piezometers screened at 3 different depths (ranging from 8 to 17 m) in lacustrine and glacial till deposits. Possible sources of the CH4 included a nearby landfill, organic wastes from previous impoundments and microbial gas derived from natural organic matter in the sediments. Isotopic analyses included ??13C, ??D, 14C, and 3H on select CH4 samples and ??D and ??18O on groundwater samples. Methane from the deepest glacial till and intermediate lacustrine deposits had ??13C values from -79 to -82???, typical of natural 'drift gas' generated by microbial CO2-reduction. The CH4 from the shallow lacustrine deposits had ??13C values from -63 to -76???, interpreted as a mixture between CH4 generated by microbial fermentation and the CO2-reduction processes within the subsurface sediments. The ??D values of all the CH4 samples were quite negative ranging from -272 to -299???. Groundwater sampled from the deeper zones also showed quite negative ??D values that explained the light ??D observed for the CH4. Radiocarbon analyses of the CH4 showed decreasing 14C activity with depth, from a high of 58 pMC in the shallow sediments to 2 pMC in the deeper glacial till. The isotopic data indicated the majority of CH4 detected in the fill deposits of this site was microbial CH4 generated from naturally buried organic matter within the subsurface sediments. However, the isotopic data of CH4 from the shallow piezometers was more variable and the possibility of some mixing with oxidized landfill CH4 could not be completely

Soil Carbon Dioxide Production and Surface Fluxes: Subsurface Physical Controls

Science.gov (United States)

Risk, D.; Kellman, L.; Beltrami, H.

Soil respiration is a critical determinant of landscape carbon balance. Variations in soil temperature and moisture patterns are important physical processes controlling soil respiration which need to be better understood. Relationships between soil respi- ration and physical controls are typically addressed using only surface flux data but other methods also exist which permit more rigorous interpretation of soil respira- tion processes. Here we use a combination of subsurface CO_{2} concentrations, surface CO_{2} fluxes and detailed physical monitoring of the subsurface envi- ronment to examine physical controls on soil CO_{2} production at four climate observatories in Eastern Canada. Results indicate that subsurface CO_{2} produc- tion is more strongly correlated to the subsurface thermal environment than the surface CO_{2} flux. Soil moisture was also found to have an important influence on sub- surface CO_{2} production, particularly in relation to the soil moisture - soil profile diffusivity relationship. Non-diffusive profile CO_{2} transport appears to be im- portant at these sites, resulting in a de-coupling of summertime surface fluxes from subsurface processes and violating assumptions that surface CO_{2} emissions are the result solely of diffusion. These results have implications for the study of soil respiration across a broad range of terrestrial environments.

CO{sub 2} huff-n-puff process in a light oil shallow carbonate reservoir. Annual report, January 1, 1996--December 31, 1996

Energy Technology Data Exchange (ETDEWEB)

Prieditis, J.; Wehner, S.

1998-01-01

The application of cyclic CO{sub 2}, often referred to as the CO{sub 2} Huff-n-Puff process, may find its niche in the maturing waterfloods of the Permian Basin. Coupling the CO{sub 2} H-n-P process to miscible flooding applications could provide the needed revenue to sufficiently mitigate near-term negative cash flow concerns in the capital intensive miscible projects. Texaco Exploration & Production Inc. and the U.S. Department of Energy have teamed up in an attempt to develop the CO{sub 2} Huff-n-Puff process in the Grayburg and San Andres formations; a light oil, shallow shelf carbonate reservoir that exists throughout the Permian Basin. A significant amount of oil reserves are located in carbonate reservoirs. Specifically, the carbonates deposited in shallow shelf (SSC) environments make up the largest percentage of known reservoirs within the Permian Basin of North America. Many of these known resources have been under waterflooding operations for decades and are at risk of abandonment if crude oil recoveries cannot be economically enhanced. The selected site for this demonstration project is the Central Vacuum Unit waterflood in Lea County, New Mexico. Miscible CO{sub 2} flooding is the process of choice for enhancing recovery of light oils and already accounts for over 12% of the Permian Basin`s daily production. There are significant probable reserves associated with future miscible CO{sub 2} projects. However, many are marginally economic at current market conditions due to large up-front capital commitments for a peak response which may be several years in the future. The resulting negative cash-flow is sometimes too much for an operator to absorb. The CO{sub 2} H-n-P process is being investigated as a near-term option to mitigate the negative cash-flow situation--allowing acceleration of inventoried miscible CO{sub 2} projects when coupled together.

The influence of biopreparations on the reduction of energy consumption and CO2 emissions in shallow and deep soil tillage.

Science.gov (United States)

Naujokienė, Vilma; Šarauskis, Egidijus; Lekavičienė, Kristina; Adamavičienė, Aida; Buragienė, Sidona; Kriaučiūnienė, Zita

2018-06-01

The application of innovation in agriculture technologies is very important for increasing the efficiency of agricultural production, ensuring the high productivity of plants, production quality, farm profitability, the positive balance of used energy, and the requirements of environmental protection. Therefore, it is a scientific problem that solid and soil surfaces covered with plant residue have a negative impact on the work, traction resistance, energy consumption, and environmental pollution of tillage machines. The objective of this work was to determine the dependence of the reduction of energy consumption and CO 2 gas emissions on different biopreparations. Experimental research was carried out in a control (SC1) and seven different biopreparations using scenarios (SC2-SC8) using bacterial and non-bacterial biopreparations in different consistencies (with essential and mineral oils, extracts of various grasses and sea algae, phosphorus, potassium, humic and gibberellic acids, copper, zinc, manganese, iron, and calcium), estimating discing and plowing as the energy consumption parameters of shallow and deep soil tillage machines, respectively. CO 2 emissions were determined by evaluating soil characteristics (such as hardness, total porosity and density). Meteorological conditions such average daily temperatures (2015-20.3 °C; 2016-16.90 °C) and precipitations (2015-6.9 mm; 2016-114.9 mm) during the month strongly influenced different results in 2015 and 2016. Substantial differences between the averages of energy consumption identified in approximately 62% of biological preparation combinations created usage scenarios. Experimental research established that crop field treatments with biological preparations at the beginning of vegetation could reduce the energy consumption of shallow tillage machines by up to approximately 23%, whereas the energy consumption of deep tillage could be reduced by up to approximately 19.2% compared with the control

Geochemical Impacts of Leaking CO2 from Subsurface Storage Reservoirs to Unconfined and Confined Aquifers

Energy Technology Data Exchange (ETDEWEB)

Qafoku, Nikolla; Brown, Christopher F.; Wang, Guohui; Sullivan, E. C.; Lawter, Amanda R.; Harvey, Omar R.; Bowden, Mark

2013-04-15

competency. The results from these investigations will provide useful information to support site selection, risk assessment, and public education efforts associated with geological, deep subsurface CO2 storage and sequestration.

The impact of CO2 on shallow groundwater chemistry: observations at a natural analog site and implications for carbon sequestration

Energy Technology Data Exchange (ETDEWEB)

Keating, Elizabeth [Los Alamos National Laboratory; Fessenden, Julianna [Los Alamos National Laboratory; Kanjorski, Nancy [NON LANL; Koning, Dan [NM BUREAU OF GEOLOGY AND MINERAL RESOURCES; Pawar, Rajesh [Los Alamos National Laboratory

2008-01-01

In a natural analog study of risks associated with carbon sequestration, impacts of CO{sub 2} on shallow groundwater quality have been measured in a sandstone aquifer in New Mexico, USA. Despite relatively high levels of dissolved CO{sub 2}, originating from depth and producing geysering at one well, pH depression and consequent trace element mobility are relatively minor effects due to the buffering capacity of the aquifer. However, local contamination due to influx of saline waters in a subset of wells is significant. Geochemical modeling of major ion concentrations suggests that high alkalinity and carbonate mineral dissolution buffers pH changes due to CO{sub 2} influx. Analysis oftrends in dissolved trace elements, chloride, and CO2 reveal no evidence of in-situ trace element mobilization. There is clear evidence, however, that As, U, and Pb are locally co-transported into the aquifer with CO{sub 2}-rich saline water. This study illustrates the role that local geochemical conditions will play in determining the effectiveness of monitoring strategies for CO{sub 2} leakage. For example, if buffering is significant, pH monitoring may not effectively detect CO2 leakage. This study also highlights potential complications that CO{sub 2}carrier fluids, such as saline waters, pose in monitoring impacts ofgeologic sequestration.

Thermal release of D{sub 2} from new Be-D co-deposits on previously baked co-deposits

Energy Technology Data Exchange (ETDEWEB)

Baldwin, M.J., E-mail: m1baldwin@ucsd.edu; Doerner, R.P.

2015-12-15

Past experiments and modeling with the TMAP code in [1, 2] indicated that Be-D co-deposited layers are less (time-wise) efficiently desorbed of retained D in a fixed low-temperature bake, as the layer grows in thickness. In ITER, beryllium rich co-deposited layers will grow in thickness over the life of the machine. Although, compared with the analyses in [1, 2], ITER presents a slightly different bake efficiency problem because of instances of prior tritium recover/control baking. More relevant to ITER, is the thermal release from a new and saturated co-deposit layer in contact with a thickness of previously-baked, less-saturated, co-deposit. Experiments that examine the desorption of saturated co-deposited over-layers in contact with previously baked under-layers are reported and comparison is made to layers of the same combined thickness. Deposition temperatures of ∼323 K and ∼373 K are explored. It is found that an instance of prior bake leads to a subtle effect on the under-layer. The effect causes the thermal desorption of the new saturated over-layer to deviate from the prediction of the validated TMAP model in [2]. Instead of the D thermal release reflecting the combined thickness and levels of D saturation in the over and under layer, experiment differs in that, i) the desorption is a fractional superposition of desorption from the saturated over-layer, with ii) that of the combined over and under -layer thickness. The result is not easily modeled by TMAP without the incorporation of a thin BeO inter-layer which is confirmed experimentally on baked Be-D co-deposits using X-ray micro-analysis.

Design and Implementation of a CO2 Flood Utilizing Advanced Reservoir Characterization and Horizontal Injection Wells In a Shallow Shelf Carbonate Approaching Waterflood Depletion, Class II; ANNUAL

International Nuclear Information System (INIS)

Czirr, K.L.; Gaddis, M.P.; Moshell, M.K.

2002-01-01

The principle objective of this project is to demonstrate the economic viability and widespread applicability of an innovative reservoir management and carbon dioxide (CO2) flood project development approach for improving CO2 flood project economics in shallow shelf carbonate (SSC) reservoirs

Shallow sub-surface structure of the central volcanic complex of Tenerife, Canary Islands: implications for the evolution and the recent reactivation of the Las Canadas caldera

Energy Technology Data Exchange (ETDEWEB)

Gottsmann, J [Department of Earth Sciences, University of Bristol, Wills Memorial Building, Queens Road, Bristol BS8 1RJ (United Kingdom); Camacho, A G; Fernandez, J [Instituto de Astronomia y Geodesia (CSIC-UCM), Ciudad Universitaria, Pza. de Ciencias, 3, 28040 Madrid (Spain); MartI, J [Institute of Earth Sciences ' Jaume Almera' , CSIC, Lluis Sole SabarIs s/n, Barcelona 08028 (Spain); Wooller, L; Rymer, H [Department of Earth and Environmental Sciences, Open University, Walton Hall, Milton Keynes, MK7 6AA (United Kingdom); GarcIa, A [Department of Volcanology, Museo Nacional de Ciencias Naturales, CSIC, C/ Jose Gutierrez Abascal, 2, 28006 Madrid (Spain)], E-mail: j.gottsmann@bristol.ac.uk

2008-10-01

We present a new local Bouguer anomaly map of the Central Volcanic Complex (CVC) of Tenerife, Spain. The high-density core of the CVC and the pronounced gravity low centred in the Las Canadas caldera (LCC) in greater detail than previously available. Mathematical construction of a subsurface model from the local anomaly data, employing a 3-D inversion enables mapping of the shallow structure beneath the complex, giving unprecedented insights into the sub-surface architecture of the complex, and shedding light on its evolution.

TMAP-7 simulation of D2 thermal release data from Be co-deposited layers

International Nuclear Information System (INIS)

Baldwin, M.J.; Schwarz-Selinger, T.; Yu, J.H.; Doerner, R.P.

2013-01-01

The efficacy of (1) bake-out at 513 K and 623 K, and (2) thermal transient (10 ms) loading to up to 1000 K, is explored for reducing D inventory in 1 μm thick Be–D (D/Be ∼0.1) co-deposited layers formed at 323 K for experiment (1) and ∼500 K for experiment (2). D release data from co-deposits are obtained by thermal desorption and used to validate a model input into the Tritium Migration and Analysis Program 7 (TMAP). In (1), good agreement with experiment is found for a TMAP model encorporating traps of activation energies, 0.80 eV and 0.98 eV, whereas an additional 2 eV trap was required to model experiment (2). Thermal release is found to be trap limited, but simulations are optimal when surface recombination is taken into account. Results suggest that thick built-up co-deposited layers will hinder ITER inventory control, and that bake periods (∼1 day) will be more effective in inventory reduction than transient thermal loading

TMAP-7 simulation of D2 thermal release data from Be co-deposited layers

Science.gov (United States)

Baldwin, M. J.; Schwarz-Selinger, T.; Yu, J. H.; Doerner, R. P.

2013-07-01

The efficacy of (1) bake-out at 513 K and 623 K, and (2) thermal transient (10 ms) loading to up to 1000 K, is explored for reducing D inventory in 1 μm thick Be-D (D/Be ˜0.1) co-deposited layers formed at 323 K for experiment (1) and ˜500 K for experiment (2). D release data from co-deposits are obtained by thermal desorption and used to validate a model input into the Tritium Migration & Analysis Program 7 (TMAP). In (1), good agreement with experiment is found for a TMAP model encorporating traps of activation energies, 0.80 eV and 0.98 eV, whereas an additional 2 eV trap was required to model experiment (2). Thermal release is found to be trap limited, but simulations are optimal when surface recombination is taken into account. Results suggest that thick built-up co-deposited layers will hinder ITER inventory control, and that bake periods (˜1 day) will be more effective in inventory reduction than transient thermal loading.

Simplified models of rates of CO2 mineralization in Geologic Carbon Storage

Science.gov (United States)

DePaolo, D. J.; Zhang, S.

2017-12-01

Geologic carbon storage (GCS) reverses the flow of carbon to the atmosphere, returning the carbon to long-term geologic storage. Models suggest that most of the injected CO2 will be "trapped" in the subsurface by physical means, but the most risk-free and permanent form of carbon storage is as carbonate minerals (Ca,Mg,Fe)CO3. The transformation of CO2 to carbonate minerals requires supply of divalent cations by dissolution of silicate minerals. Available data suggest that rates of transformation are difficult to predict. We show that the chemical kinetic observations and experimental results, when reduced to a single timescale that describes the fractional rate at which cations are released to solution by mineral dissolution, show sufficiently systematic behavior that the rates of mineralization can be estimated with reasonable certainty. Rate of mineralization depends on both the abundance (determined by the reservoir rock mineralogy) and the rate at which cations are released by dissolution into pore fluid that has been acidified with dissolved CO2. Laboratory-measured rates and field observations give values spanning 8 to 10 orders of magnitude, but when evaluated in the context of reservoir-scale reactive transport simulations, this range becomes much smaller. Reservoir scale simulations indicate that silicate mineral dissolution and subsequent carbonate mineral precipitation occur at pH 4.5 to 6, fluid flow velocity less than 5m/yr, and 50-100 years or more after the start of injection. These constraints lead to estimates of 200 to 2000 years for conversion of 60-90% of injected CO2 when the reservoir rock has a sufficient volume fraction of divalent cation-bearing silicate minerals (ca. 20%), and confirms that when reservoir rock mineralogy is not favorable the fraction of CO2 converted to carbonate minerals is minimal over 104 years. A sufficient amount of reactive minerals represents the condition by which the available cations per volume of rock plus pore

Evaluating Potential for Large Releases from CO2 Storage Reservoirs: Analogs, Scenarios, and Modeling Needs

International Nuclear Information System (INIS)

Birkholzer, Jens; Pruess, Karsten; Lewicki, Jennifer; Tsang, Chin-Fu; Karimjee, Anhar

2005-01-01

While the purpose of geologic storage of CO 2 in deep saline formations is to trap greenhouse gases underground, the potential exists for CO 2 to escape from the target reservoir, migrate upward along permeable pathways, and discharge at the land surface. Such discharge is not necessarily a serious concern, as CO 2 is a naturally abundant and relatively benign gas in low concentrations. However, there is a potential risk to health, safety and environment (HSE) in the event that large localized fluxes of CO 2 were to occur at the land surface, especially where CO 2 could accumulate. In this paper, we develop possible scenarios for large CO 2 fluxes based on the analysis of natural analogues, where large releases of gas have been observed. We are particularly interested in scenarios which could generate sudden, possibly self-enhancing, or even eruptive release events. The probability for such events may be low, but the circumstances under which they might occur and potential consequences need to be evaluated in order to design appropriate site selection and risk management strategies. Numerical modeling of hypothetical test cases is needed to determine critical conditions for such events, to evaluate whether such conditions may be possible at designated storage sites, and, if applicable, to evaluate the potential HSE impacts of such events and design appropriate mitigation strategies

Reactive Transport Analysis of Fault 'Self-sealing' Associated with CO2 Storage

Science.gov (United States)

Patil, V.; McPherson, B. J. O. L.; Priewisch, A.; Franz, R. J.

2014-12-01

We present an extensive hydrologic and reactive transport analysis of the Little Grand Wash fault zone (LGWF), a natural analog of fault-associated leakage from an engineered CO2 repository. Injecting anthropogenic CO2 into the subsurface is suggested for climate change mitigation. However, leakage of CO2 from its target storage formation into unintended areas is considered as a major risk involved in CO2 sequestration. In the event of leakage, permeability in leakage pathways like faults may get sealed (reduced) due to precipitation or enhanced (increased) due to dissolution reactions induced by CO2-enriched water, thus influencing migration and fate of the CO2. We hypothesize that faults which act as leakage pathways can seal over time in presence of CO2-enriched waters. An example of such a fault 'self-sealing' is found in the LGWF near Green River, Utah in the Paradox basin, where fault outcrop shows surface and sub-surface fractures filled with calcium carbonate (CaCO3). The LGWF cuts through multiple reservoirs and seal layers piercing a reservoir of naturally occurring CO2, allowing it to leak into overlying aquifers. As the CO2-charged water from shallower aquifers migrates towards atmosphere, a decrease in pCO2 leads to supersaturation of water with respect to CaCO3, which precipitates in the fractures of the fault damage zone. In order to test the nature, extent and time-frame of the fault sealing, we developed reactive flow simulations of the LGWF. Model parameters were chosen based on hydrologic measurements from literature. Model geochemistry was constrained by water analysis of the adjacent Crystal Geyser and observations from a scientific drilling test conducted at the site. Precipitation of calcite in the top portion of the fault model led to a decrease in the porosity value of the damage zone, while clay precipitation led to a decrease in the porosity value of the fault core. We found that the results were sensitive to the fault architecture

Integrated geomechanical modelling for deep subsurface damage

NARCIS (Netherlands)

Wees, J.D. van; Orlic, B.; Zijl, W.; Jongerius, P.; Schreppers, G.J.; Hendriks, M.

2001-01-01

Government, E&P and mining industry increasingly demand fundamental insight and accurate predictions on subsurface and surface deformation and damage due to exploitation of subsurface natural resources, and subsurface storage of energy residues (e.g. CO2). At this moment deformation is difficult to

Anatomy of Old Faithful from subsurface seismic imaging of the Yellowstone Upper Geyser Basin

KAUST Repository

Wu, Sin-Mei

2017-10-03

The Upper Geyser Basin in Yellowstone National Park contains one of the highest concentrations of hydrothermal features on Earth including the iconic Old Faithful geyser. Although this system has been the focus of many geological, geochemical, and geophysical studies for decades, the shallow (<200 m) subsurface structure remains poorly characterized. To investigate the detailed subsurface geologic structure including the hydrothermal plumbing of the Upper Geyser Basin, we deployed an array of densely spaced three-component nodal seismographs in November of 2015. In this study, we extract Rayleigh-wave seismic signals between 1-10 Hz utilizing non-diffusive seismic waves excited by nearby active hydrothermal features with the following results. 1) imaging the shallow subsurface structure by utilizing stationary hydrothermal activity as a seismic source, 2) characterizing how local geologic conditions control the formation and location of the Old Faithful hydrothermal system, and 3) resolving a relatively shallow (10-60 m) and large reservoir located ~100 m southwest of Old Faithful geyser.

Mineral storage of CO2/H2S gas mixture injection in basaltic rocks

Science.gov (United States)

Clark, D. E.; Gunnarsson, I.; Aradottir, E. S.; Oelkers, E. H.; Sigfússon, B.; Snæbjörnsdottír, S. Ó.; Matter, J. M.; Stute, M.; Júlíusson, B. M.; Gíslason, S. R.

2017-12-01

Carbon capture and storage is one solution to reducing CO2 emissions in the atmosphere. The long-term geological storage of buoyant supercritical CO2 requires high integrity cap rock. Some of the risk associated with CO2 buoyancy can be overcome by dissolving CO2 into water during its injection, thus eliminating its buoyancy. This enables injection into fractured rocks, such as basaltic rocks along oceanic ridges and on continents. Basaltic rocks are rich in divalent cations, Ca2+, Mg2+ and Fe2+, which react with CO2 dissolved in water to form stable carbonate minerals. This possibility has been successfully tested as a part of the CarbFix CO2storage pilot project at the Hellisheiði geothermal power plant in Iceland, where they have shown mineralization occurs in less than two years [1, 2]. Reykjavik Energy and the CarbFix group has been injecting a mixture of CO2 and H2S at 750 m depth and 240-250°C since June 2014; by 1 January 2016, 6290 tons of CO2 and 3530 tons of H2S had been injected. Once in the geothermal reservoir, the heat exchange and sufficient dissolution of the host rock neutralizes the gas-charged water and saturates the formation water respecting carbonate and sulfur minerals. A thermally stable inert tracer was also mixed into the stream to monitor the subsurface transport and to assess the degree of subsurface carbonation and sulfide precipitation [3]. Water and gas samples have been continuously collected from three monitoring wells and geochemically analyzed. Based on the results, mineral saturation stages have been defined. These results and tracer mass balance calculations are used to evaluate the rate and magnitude of CO2 and H2S mineralization in the subsurface, with indications that mineralization of carbon and sulfur occurs within months. [1] Gunnsarsson, I., et al. (2017). Rapid and cost-effective capture and subsurface mineral storage of carbon and sulfur. Manuscript submitted for publication. [2] Matter, J., et al. (2016). Rapid

Frequency band adjustment match filtering based on variable frequency GPR antennas pairing scheme for shallow subsurface investigations

Science.gov (United States)

Shaikh, Shahid Ali; Tian, Gang; Shi, Zhanjie; Zhao, Wenke; Junejo, S. A.

2018-02-01

Ground penetrating Radar (GPR) is an efficient tool for subsurface geophysical investigations, particularly at shallow depths. The non-destructiveness, cost efficiency, and data reliability are the important factors that make it an ideal tool for the shallow subsurface investigations. Present study encompasses; variations in central frequency of transmitting and receiving GPR antennas (Tx-Rx) have been analyzed and frequency band adjustment match filters are fabricated and tested accordingly. Normally, the frequency of both the antennas remains similar to each other whereas in this study we have experimentally changed the frequencies of Tx-Rx and deduce the response. Instead of normally adopted three pairs, a total of nine Tx-Rx pairs were made from 50 MHz, 100 MHz, and 200 MHz antennas. The experimental data was acquired at the designated near surface geophysics test site of the Zhejiang University, Hangzhou, China. After the impulse response analysis of acquired data through conventional as well as varied Tx-Rx pairs, different swap effects were observed. The frequency band and exploration depth are influenced by transmitting frequencies rather than the receiving frequencies. The impact of receiving frequencies was noticed on the resolution; the more noises were observed using the combination of high frequency transmitting with respect to low frequency receiving. On the basis of above said variable results we have fabricated two frequency band adjustment match filters, the constant frequency transmitting (CFT) and the variable frequency transmitting (VFT) frequency band adjustment match filters. By the principle, the lower and higher frequency components were matched and then incorporated with intermediate one. Therefore, this study reveals that a Tx-Rx combination of low frequency transmitting with high frequency receiving is a better choice. Moreover, both the filters provide better radargram than raw one, the result of VFT frequency band adjustment filter is

A Strategy to Conduct an Analysis of the Long-Term Performance of Low-Activity Waste Glass in a Shallow Subsurface Disposal System at Hanford

Energy Technology Data Exchange (ETDEWEB)

Neeway, James J.; Pierce, Eric M.; Freedman, Vicky L.; Ryan, Joseph V.; Qafoku, Nikolla

2014-08-04

The federal facilities located on the Hanford Site in southeastern Washington State have been used extensively by the U.S. government to produce nuclear materials for the U.S. strategic defense arsenal. Currently, the Hanford Site is under the stewardship of the U.S. Department of Energy (DOE) Office of Environmental Management (EM). A large inventory of radioactive and mixed waste resulting from the production of nuclear materials has accumulated, mainly in 177 underground single- and double-shell tanks located in the central plateau of the Hanford Site (Mann et al., 2001). The DOE-EM Office of River Protection (ORP) is proceeding with plans to immobilize and permanently dispose of the low-activity waste (LAW) fraction onsite in a shallow subsurface disposal facility (the Integrated Disposal Facility [IDF]). Pacific Northwest National Laboratory (PNNL) was contracted to provide the technical basis for estimating radionuclide release from the engineered portion of the IDF (the source term) as part of an immobilized low-activity waste (ILAW) glass testing program to support future IDF performance assessments (PAs).

Improved Understanding of Carbon Storage Risk Via Controlled-Release Experiments

Science.gov (United States)

Birkholzer, J. T.; Guglielmi, Y.; Rutqvist, J.; Zheng, L.; Spycher, N.

2014-12-01

Two issues are often recognized as main risk drivers for carbon storage projects. The first is the possibility of pressure-induced slip of pre-existing faults, which can lead to breaching of seals to CO2 storage reservoirs. Although the mechanics of induced seismicity are well known, the characteristics of such slip events are poorly constrained and significant questions remain. The second is the potential impact of leaking CO2 on the quality of shallow potable groundwater. While several studies have been conducted using laboratory tests, natural analogues, and numerical models to evaluate the water quality changes induced by elevated CO2 concentrations, predictive understanding of these coupled processes remains limited in realistic field settings. We discuss in this invited contribution two controlled-release field experiments targeting remaining science gaps associated with induced seismicity and groundwater chemistry. The first experiment is a planned active fault slip experiment conducted in an underground research laboratory (URL) in a hardened shale formation that serves as a caprock analog. The critically stressed fault will be perturbed by the injection of fluid under pressure to simulate the influence of CO2 overpressure. The in situ reactivation experiment will use a novel borehole deformation tool that assesses the magnitude of overpressure required to cause slip, defines the mode of this slip as creeping (aseismic) or rapid (seismic), and measures the evolution of permeability on the fault. The second controlled-release field experiment was conducted in 2011/2012 to simulate the release of CO2 from a geologic storage site and study the transport as well as the chemical mechanisms leading to the CO2-induced mobilization of trace elements in a shallow aquifer. The field test involved a dipole system in which the shallow groundwater was pumped from one well, saturated with CO2 at the pressure corresponding to the hydraulic pressure of the aquifer, and

TMAP-7 simulation of D{sub 2} thermal release data from Be co-deposited layers

Energy Technology Data Exchange (ETDEWEB)

Baldwin, M.J., E-mail: mbaldwin@ferp.ucsd.edu [Center for Energy Research, University of California at San Diego, La Jolla, CA 92093-0417 (United States); Schwarz-Selinger, T. [Max-Planck-Institut für Plasmaphysik, EURATOM Association, Boltzmannstrasse 2, 85748 Garching (Germany); Yu, J.H. [Center for Energy Research, University of California at San Diego, La Jolla, CA 92093-0417 (United States); Doerner, R.P., E-mail: rdoerner@ucsd.edu [Center for Energy Research, University of California at San Diego, La Jolla, CA 92093-0417 (United States)

2013-07-15

The efficacy of (1) bake-out at 513 K and 623 K, and (2) thermal transient (10 ms) loading to up to 1000 K, is explored for reducing D inventory in 1 μm thick Be–D (D/Be ∼0.1) co-deposited layers formed at 323 K for experiment (1) and ∼500 K for experiment (2). D release data from co-deposits are obtained by thermal desorption and used to validate a model input into the Tritium Migration and Analysis Program 7 (TMAP). In (1), good agreement with experiment is found for a TMAP model encorporating traps of activation energies, 0.80 eV and 0.98 eV, whereas an additional 2 eV trap was required to model experiment (2). Thermal release is found to be trap limited, but simulations are optimal when surface recombination is taken into account. Results suggest that thick built-up co-deposited layers will hinder ITER inventory control, and that bake periods (∼1 day) will be more effective in inventory reduction than transient thermal loading.

Is it only CO{sub 2} that matters? A life cycle perspective on shallow geothermal systems

Energy Technology Data Exchange (ETDEWEB)

Saner, Dominik; Juraske, Ronnie; Hellweg, Stefanie [Group for Ecological Systems Design, Institute of Environmental Engineering, ETH Zurich, Schafmattstrasse 6, CH-8093 Zurich (Switzerland); Kuebert, Markus [Systherma GmbH, Am Haag 12, D-72181 Starzach-Felldorf (Germany); Blum, Philipp [Karlsruhe Institute of Technology (KIT), Institute for Applied Geosciences (AGW), Kaiserstrasse 12, D-76131 Karlsruhe (Germany); Bayer, Peter [Engineering Geology, Geological Institute, ETH Zurich, Sonneggstrasse 5, CH-8092 Zurich (Switzerland)

2010-09-15

Shallow geothermal systems such as open and closed geothermal heat pump (GHP) systems are considered to be an efficient and renewable energy technology for cooling and heating of buildings and other facilities. The numbers of installed ground source heat pump (GSHP) systems, for example, is continuously increasing worldwide. The objective of the current study is not only to discuss the net energy consumption and greenhouse gas (GHG) emissions or savings by GHP operation, but also to fully examine environmental burdens and benefits related to applications of such shallow geothermal systems by employing a state-of the-art life cycle assessment (LCA). The latter enables us to assess the entire energy flows and resources use for any product or service that is involved in the life cycle of such a technology. The applied life cycle impact assessment methodology (ReCiPe 2008) shows the relative contributions of resources depletion (34%), human health (43%) and ecosystem quality (23%) of such GSHP systems to the overall environmental damage. Climate change, as one impact category among 18 others, contributes 55.4% to the total environmental impacts. The life cycle impact assessment also demonstrates that the supplied electricity for the operation of the heat pump is the primary contributor to the environmental impact of GSHP systems, followed by the heat pump refrigerant, production of the heat pump, transport, heat carrier liquid, borehole and borehole heat exchanger (BHE). GHG emissions related to the use of such GSHP systems are carefully reviewed; an average of 63 t CO{sub 2} equivalent emissions is calculated for a life cycle of 20 years using the Continental European electricity mix with 0.599 kg CO{sub 2} eq/kWh. However, resulting CO{sub 2} eq savings for Europe, which are between -31% and 88% in comparison to conventional heating systems such as oil fired boilers and gas furnaces, largely depend on the primary resource of the supplied electricity for the heat pump

Non-Volcanic release of CO2 in Italy: quantification, conceptual models and gas hazard

Science.gov (United States)

Chiodini, G.; Cardellini, C.; Caliro, S.; Avino, R.

2011-12-01

Central and South Italy are characterized by the presence of many reservoirs naturally recharged by CO2 of deep provenance. In the western sector, the reservoirs feed hundreds of gas emissions at the surface. Many studies in the last years were devoted to (i) elaborating a map of CO2 Earth degassing of the region; (ii) to asses the gas hazard; (iii) to develop methods suitable for the measurement of the gas fluxes from different types of emissions; (iv) to elaborate the conceptual model of Earth degassing and its relation with the seismic activity of the region and (v) to develop physical numerical models of CO2 air dispersion. The main results obtained are: 1) A general, regional map of CO2 Earth degassing in Central Italy has been elaborated. The total flux of CO2 in the area has been estimated in ~ 10 Mt/a which are released to the atmosphere trough numerous dangerous gas emissions or by degassing spring waters (~ 10 % of the CO2 globally estimated to be released by the Earth trough volcanic activity). 2) An on line, open access, georeferenced database of the main CO2 emissions (~ 250) was settled up (http://googas.ov.ingv.it). CO2 flux > 100 t/d characterise 14% of the degassing sites while CO2 fluxes from 100 t/d to 10 t/d have been estimated for about 35% of the gas emissions. 3) The sites of the gas emissions are not suitable for life: the gas causes many accidents to animals and people. In order to mitigate the gas hazard a specific model of CO2 air dispersion has been developed and applied to the main degassing sites. A relevant application regarded Mefite d'Ansanto, southern Apennines, which is the largest natural emission of low temperature CO2 rich gases, from non-volcanic environment, ever measured in the Earth (˜2000 t/d). Under low wind conditions, the gas flows along a narrow natural channel producing a persistent gas river which has killed over a period of time many people and animals. The application of the physical numerical model allowed us to

Microbiological and Geochemical Survey of CO2-Dominated Mofette and Mineral Waters of the Cheb Basin, Czech Republic

Directory of Open Access Journals (Sweden)

Patryk Krauze

2017-12-01

Full Text Available The Cheb Basin (NW Bohemia, Czech Republic is a shallow, neogene intracontinental basin. It is a non-volcanic region which features frequent earthquake swarms and large-scale diffuse degassing of mantle-derived CO2 at the surface that occurs in the form of CO2-rich mineral springs and wet and dry mofettes. So far, the influence of CO2 degassing onto the microbial communities has been studied for soil environments, but not for aquatic systems. We hypothesized, that deep-trenching CO2 conduits interconnect the subsurface with the surface. This admixture of deep thermal fluids should be reflected in geochemical parameters and in the microbial community compositions. In the present study four mineral water springs and two wet mofettes were investigated through an interdisciplinary survey. The waters were acidic and differed in terms of organic carbon and anion/cation concentrations. Element geochemical and isotope analyses of fluid components were used to verify the origin of the fluids. Prokaryotic communities were characterized through quantitative PCR and Illumina 16S rRNA gene sequencing. Putative chemolithotrophic, anaerobic and microaerophilic organisms connected to sulfur (e.g., Sulfuricurvum, Sulfurimonas and iron (e.g., Gallionella, Sideroxydans cycling shaped the core community. Additionally, CO2-influenced waters form an ecosystem containing many taxa that are usually found in marine or terrestrial subsurface ecosystems. Multivariate statistics highlighted the influence of environmental parameters such as pH, Fe2+ concentration and conductivity on species distribution. The hydrochemical and microbiological survey introduces a new perspective on mofettes. Our results support that mofettes are either analogs or rather windows into the deep biosphere and furthermore enable access to deeply buried paleo-sediments.

The fluid flow consequences of CO2 migration from 1000 to 600 metres upon passing the critical conditions of CO2

NARCIS (Netherlands)

Meer, L.G.H.; Hofstee, C.; Orlic, B.

2009-01-01

The minimum injection depth for the storage of CO2 is normally set at 800 metres. At and beyond this depth in the subsurface conditions exist where CO2 is in a so-called critical state. The supercritical CO2 has a viscosity comparable to that of a normal gas and a liquid-like density, Due to the

Potential for Nitrogen Fixation and Nitrification in the Granite-Hosted Subsurface at Henderson Mine, CO

Science.gov (United States)

Swanner, Elizabeth D.; Templeton, Alexis S.

2011-01-01

The existence of life in the deep terrestrial subsurface is established, yet few studies have investigated the origin of nitrogen that supports deep life. Previously, 16S rRNA gene surveys cataloged a diverse microbial community in subsurface fluids draining from boreholes 3000 feet deep at Henderson Mine, CO, USA (Sahl et al., 2008). The prior characterization of the fluid chemistry and microbial community forms the basis for the further investigation here of the source of NH4+. The reported fluid chemistry included N2, NH4+ (5–112 μM), NO2− (27–48 μM), and NO3− (17–72 μM). In this study, the correlation between low NH4+ concentrations in dominantly meteoric fluids and higher NH4+ in rock-reacted fluids is used to hypothesize that NH4+ is sourced from NH4+-bearing biotite. However, biotite samples from the host rocks and ore-body minerals were analyzed by Fourier transform infrared (FTIR) microscopy and none-contained NH4+. However, the nitrogenase-encoding gene nifH was successfully amplified from DNA of the fluid sample with high NH4+, suggesting that subsurface microbes have the capability to fix N2. If so, unregulated nitrogen fixation may account for the relatively high NH4+ concentrations in the fluids. Additionally, the amoA and nxrB genes for archaeal ammonium monooxygenase and nitrite oxidoreductase, respectively, were amplified from the high NH4+ fluid DNA, while bacterial amoA genes were not. Putative nitrifying organisms are closely related to ammonium-oxidizing Crenarchaeota and nitrite-oxidizing Nitrospira detected in other subsurface sites based upon 16S rRNA sequence analysis. Thermodynamic calculations underscore the importance of NH4+ as an energy source in a subsurface nitrification pathway. These results suggest that the subsurface microbial community at Henderson is adapted to the low nutrient and energy environment by their capability of fixing nitrogen, and that fixed nitrogen may support subsurface biomass via

In situ gamma-ray spectrometric analysis of radionuclide distributions at a commercial shallow land burial site

International Nuclear Information System (INIS)

Kirby, L.J.; Campbell, R.M.

1984-10-01

Gamma-ray spectrometric analysis conducted at the Maxey Flats, Kentucky (USA) shallow land burial site confirmed that the waste radionuclides have been retained largely within the restricted area of the burial site. Concentrations of 137 Cs and 60 Co were comparable with those originating from global fallout and lower than concentrations measured in several other areas having similar rainfall. In-situ spectrometric analyses, corroborated by soil sample and vegetation analyses, indicate that the site has influenced 60 Co levels slightly in the west drainage channel, but 137 Cs did not originate from the site. Concentrations of 60 Co, 90 Sr and 137 Cs determined in subsurface soils by well logging techniques confirmed that subsurface migration of waste-derived radionuclides to points outside the restricted area has not been a significant source of contamination of the environs adjacent to the site. 8 references, 8 figures

Supercritical CO2 uptake by nonswelling phyllosilicates.

Science.gov (United States)

Wan, Jiamin; Tokunaga, Tetsu K; Ashby, Paul D; Kim, Yongman; Voltolini, Marco; Gilbert, Benjamin; DePaolo, Donald J

2018-01-30

Interactions between supercritical (sc) CO 2 and minerals are important when CO 2 is injected into geologic formations for storage and as working fluids for enhanced oil recovery, hydraulic fracturing, and geothermal energy extraction. It has previously been shown that at the elevated pressures and temperatures of the deep subsurface, scCO 2 alters smectites (typical swelling phyllosilicates). However, less is known about the effects of scCO 2 on nonswelling phyllosilicates (illite and muscovite), despite the fact that the latter are the dominant clay minerals in deep subsurface shales and mudstones. Our studies conducted by using single crystals, combining reaction (incubation with scCO 2 ), visualization [atomic force microscopy (AFM)], and quantifications (AFM, X-ray photoelectron spectroscopy, X-ray diffraction, and off-gassing measurements) revealed unexpectedly high CO 2 uptake that far exceeded its macroscopic surface area. Results from different methods collectively suggest that CO 2 partially entered the muscovite interlayers, although the pathways remain to be determined. We hypothesize that preferential dissolution at weaker surface defects and frayed edges allows CO 2 to enter the interlayers under elevated pressure and temperature, rather than by diffusing solely from edges deeply into interlayers. This unexpected uptake of CO 2 , can increase CO 2 storage capacity by up to ∼30% relative to the capacity associated with residual trapping in a 0.2-porosity sandstone reservoir containing up to 18 mass % of illite/muscovite. This excess CO 2 uptake constitutes a previously unrecognized potential trapping mechanism. Copyright © 2018 the Author(s). Published by PNAS.

CO2-Water-Rock Wettability: Variability, Influencing Factors, and Implications for CO2 Geostorage.

Science.gov (United States)

Iglauer, Stefan

2017-05-16

Carbon geosequestration (CGS) has been identified as a key technology to reduce anthropogenic greenhouse gas emissions and thus significantly mitigate climate change. In CGS, CO 2 is captured from large point-source emitters (e.g., coal fired power stations), purified, and injected deep underground into geological formations for disposal. However, the CO 2 has a lower density than the resident formation brine and thus migrates upward due to buoyancy forces. To prevent the CO 2 from leaking back to the surface, four trapping mechanisms are used: (1) structural trapping (where a tight caprock acts as a seal barrier through which the CO 2 cannot percolate), (2) residual trapping (where the CO 2 plume is split into many micrometer-sized bubbles, which are immobilized by capillary forces in the pore network of the rock), (3) dissolution trapping (where CO 2 dissolves in the formation brine and sinks deep into the reservoir due to a slight increase in brine density), and (4) mineral trapping (where the CO 2 introduced into the subsurface chemically reacts with the formation brine or reservoir rock or both to form solid precipitates). The efficiency of these trapping mechanisms and the movement of CO 2 through the rock are strongly influenced by the CO 2 -brine-rock wettability (mainly due to the small capillary-like pores in the rock which form a complex network), and it is thus of key importance to rigorously understand CO 2 -wettability. In this context, a substantial number of experiments have been conducted from which several conclusions can be drawn: of prime importance is the rock surface chemistry, and hydrophilic surfaces are water-wet while hydrophobic surfaces are CO 2 -wet. Note that CO 2 -wet surfaces dramatically reduce CO 2 storage capacities. Furthermore, increasing pressure, salinity, or dissolved ion valency increases CO 2 -wettability, while the effect of temperature is not well understood. Indeed theoretical understanding of CO 2 -wettability and the

Metal release from sandstones under experimentally and numerically simulated CO2 leakage conditions.

Science.gov (United States)

Kirsch, Katie; Navarre-Sitchler, Alexis K; Wunsch, Assaf; McCray, John E

2014-01-01

Leakage of CO2 from a deep storage formation into an overlying potable aquifer may adversely impact water quality and human health. Understanding CO2-water-rock interactions is therefore an important step toward the safe implementation of geologic carbon sequestration. This study targeted the geochemical response of siliclastic rock, specifically three sandstones of the Mesaverde Group in northwestern Colorado. To test the hypothesis that carbonate minerals, even when present in very low levels, would be the primary source of metals released into a CO2-impacted aquifer, two batch experiments were conducted. Samples were reacted for 27 days with water and CO2 at partial pressures of 0.01 and 1 bar, representing natural background levels and levels expected in an aquifer impacted by a small leakage, respectively. Concentrations of major (e.g., Ca, Mg) and trace (e.g., As, Ba, Cd, Fe, Mn, Pb, Sr, U) elements increased rapidly after CO2 was introduced into the system, but did not exceed primary Maximum Contaminant Levels set by the U.S. Environmental Protection Agency. Results of sequential extraction suggest that carbonate minerals, although volumetrically insignificant in the sandstone samples, are the dominant source of mobile metals. This interpretation is supported by a simple geochemical model, which could simulate observed changes in fluid composition through CO2-induced calcite and dolomite dissolution.

Shallow PS-logging by high frequency wave; Koshuha wo mochiita senbu PS kenso

Energy Technology Data Exchange (ETDEWEB)

Nakajima, A; Miyazawa, M; Azuma, H [OYO Corp., Tokyo (Japan)

1996-05-01

This paper describes the following matters on down-hole PS logging in shallow subsurface. Determining an elastic wave velocity structure in shallow subsurface with high accuracy by using down-hole PS logging requires reduction of errors in reading travel time. Therefore, a high-frequency vibration source was fabricated with an objective to raise frequencies of waves used for the measurement. Measurements were made on two holes, A and B, at a measurement interval of 0.5 m, whereas at the hole A a measurement was performed simultaneously by using a normal type (low-frequency) vibration source. A spectral analysis on the waveform record revealed that the frequencies with each vibration source were 127 Hz and 27 Hz for the hole A, 115 Hz for the hole B, and the S/N ratio was all the same for both holes. When the high-frequency vibration source was used, the velocity was determined at accuracy of 5% over the whole length of the shallow section. When the low-frequency vibration source was used, sections with the velocity determining error greater than 5% were found, and it was not possible to derive the velocity structure in the shallow subsurface in fine segments. 3 refs., 8 figs., 2 tabs.

Development of a CO2 releasing co-formulation 1 based on starch, Saccharomyces cerevisiae and Beauveria bassiana attractive towards western corn rootworm larvae

Science.gov (United States)

CO2 is known as an attractant for many soil-dwelling pests. To implement an attract-and-kill strategy for soil pest control, CO2 emitting formulations need to be developed. This work aimed at the development of a slow release bead system in order to bridge the gap between application and hatching of...

3D modelling of the shallow subsurface of Zeeland, the Netherlands

NARCIS (Netherlands)

Stafleu, J.; Busschers, F.S.; Maljers, D.; Menkovic, A.

2011-01-01

The Geological Survey of the Netherlands aims at building a 3D geological voxel model of the upper 30 m of the subsurface of the Netherlands in order to provide a sound basis for subsurface related questions on, amongst others, groundwater extraction and management, land subsidence studies,

Decadal-scale variability of diffuse CO2 emissions and seismicity revealed from long-term monitoring (1995–2013) at Mammoth Mountain, California, USA

Science.gov (United States)

Werner, Cynthia A.; Bergfeld, Deborah; Farrar, Chris; Doukas, Michael P.; Kelly, Peter; Kern, Christoph

2014-01-01

Mammoth Mountain, California, is a dacitic volcano that has experienced several periods of unrest since 1989. The onset of diffuse soil CO2 emissions at numerous locations on the flanks of the volcano began in 1989–1990 following an 11-month period of heightened seismicity. CO2 emission rates were measured yearly from 1995 to 2013 at Horseshoe Lake (HSL), the largest tree kill area on Mammoth Mountain, and measured intermittently at four smaller degassing areas around Mammoth from 2006 to 2013. The long-term record at HSL shows decadal-scale variations in CO2 emissions with two peaks in 2000–2001 and 2011–2012, both of which follow peaks in seismicity by 2–3 years. Between 2000 and 2004 emissions gradually declined during a seismically quiet period, and from 2004 to 2009 were steady at ~ 100 metric tonnes per day (t d− 1). CO2emissions at the four smaller tree-kill areas also increased by factors of 2–3 between 2006 and 2011–2012, demonstrating a mountain-wide increase in degassing. Delays between the peaks in seismicity and degassing have been observed at other volcanic and hydrothermal areas worldwide, and are thought to result from an injection of deep CO2-rich fluid into shallow subsurface reservoirs causing a pressurization event with a delayed transport to the surface. Such processes are consistent with previous studies at Mammoth, and here we highlight (1) the mountain-wide response, (2) the characteristic delay of 2–3 years, and (3) the roughly decadal reoccurrence interval for such behavior. Our best estimate of total CO2 degassing from Mammoth Mountain was 416 t d− 1 in 2011 during the peak of emissions, over half of which was emitted from HSL. The cumulative release of CO2 between 1995 and 2013 from diffuse emissions is estimated to be ~ 2–3 Mt, and extrapolation back to 1989 gives ~ 4.8 Mt. This amount of CO2 release is similar to that produced by the mid-sized (VEI 3) 2009 eruption of Redoubt Volcano in Alaska (~ 2.3�

Revealing fate of CO2 leakage pathways in the Little Grand Wash Fault, Green River, Utah

Science.gov (United States)

Han, K.; Han, W. S.; Watson, Z. T.; Guyant, E.; Park, E.

2015-12-01

To assure long-term security of geologic carbon sequestration site, evaluation of natural CO2 leakage should be preceded before actual construction of the CO2 facility by comparing natural and artificial reservoir systems. The Little Grand Wash fault is located at the northwestern margin of the Paradox Basin and roles on a bypass of deep subsurface CO2 and brine water onto the surface, e.g., cold water geyser, CO2 spring, and surface travertine deposits. CO2 degassed out from brine at the Little Grand Wash fault zone may react with formation water and minerals while migrating through the fault conduit. Leakage observed by soil CO2 flux on the fault trace shows this ongoing transition of CO2, from supersaturated condition in deep subsurface to shallow surface equilibria. The present study aims to investigate the reactions induced by changes in hydrological and mineralogical factors inside of the fault zone. The methodology to develop site-specific geochemical model of the Little Grand Wash Fault combines calculated mechanical movements of each fluid end-member, along with chemical reactions among fluid, free CO2 gas and rock formations. Reactive transport modeling was conducted to simulate these property changes inside of the fault zone, using chemistry dataset based on 86 effluent samples of CO2 geysers, springs and in situ formation water from Entrada, Carmel, and Navajo Sandstone. Meanwhile, one- and two-dimensional models were separately developed to delineate features mentioned above. The results from the 3000-year simulation showed an appearance of self-sealing processes near the surface of the fault conduit. By tracking physicochemical changes at the depth of 15 m on the 2-dimensional model, significant changes induced by fluid mixing were indicated. Calculated rates of precipitation for calcite, illite, and pyrite showed increase in 2.6 x 10-4, 2.25 x 10-5, and 3.0 x 10-6 in mineral volume fraction at the depth of 15m, respectively. Concurrently

CO2 point sources and subsurface storage capacities for CO2 in aquifers in Norway

International Nuclear Information System (INIS)

Boee, Reidulv; Magnus, Christian; Osmundsen, Per Terje; Rindstad, Bjoern Ivar

2002-01-01

The GESTCO project comprises a study of the distribution and coincidence of thermal CO 2 emission sources and location/quality of geological storage capacity in Europe. Four of the most promising types of geological storage are being studied. 1. Onshore/offshore saline aquifers with or without lateral seal. 2. Low entalpy geothermal reservoirs. 3. Deep methane-bearing coal beds and abandoned coal and salt mines. 4. Exhausted or near exhausted hydrocarbon structures. In this report we present an inventory of CO 2 point sources in Norway (1999) and the results of the work within Study Area C: Deep saline aquifers offshore/near shore Northern and Central Norway. Also offshore/near shore Southern Norway has been included while the Barents Sea is not described in any detail. The most detailed studies are on the Tilje and Aare Formations on the Troendelag Platform off Mid-Norway and on the Sognefjord, Fensfjord and Krossfjord Formations, southeast of the Troll Field off Western Norway. The Tilje Formation has been chosen as one of the cases to be studied in greater detail (numerical modelling) in the project. This report shows that offshore Norway, there are concentrations of large CO 2 point sources in the Haltenbanken, the Viking Graben/Tampen Spur area, the Southern Viking Graben and the central Trough, while onshore Norway there are concentrations of point sources in the Oslofjord/Porsgrund area, along the coast of western Norway and in the Troendelag. A number of aquifers with large theoretical CO 2 storage potential are pointed out in the North Sea, the Norwegian Sea and in the Southern Barents Sea. The storage capacity in the depth interval 0.8 - 4 km below sea level is estimated to be ca. 13 Gt (13000000000 tonnes) CO 2 in geological traps (outside hydrocarbon fields), while the storage capacity in aquifers not confined to traps is estimated to be at least 280 Gt CO 2 . (Author)

CO2 capture and storage in the subsurface - A technological pathway for combating climate change

International Nuclear Information System (INIS)

2007-10-01

The Earth is warning abnormally. The guilty parties are so-called 'greenhouse gases' (GHG), the main one being carbon dioxide (CO 2 ). Produced in large quantities by human activities such as transportation, domestic uses and industry, this gas is essentially given off when fossil fuels - coal, oil or gas - are burned. In addition to efforts to reduce energy consumption and develop renewable energy sources, CO 2 capture and storage emerges as an option insofar as fossil fuels will continue to be exploited. Since release of the IPCC special report in 2005, mobilization has flourished worldwide for the development of this technological pathway enabling the use of fossil fuels without CO 2 emissions, thus biding time until the arrival of alternate energy resources. This brochure goes back over the context of greenhouse gas emissions reductions and addresses at length the achievements and projects in the field of CO 2 capture and storage. It also provides a detailed description of on-going technological research and development programmes, highlighting both accomplishments and orientations where progress is expected. It takes stock of recent progress, particularly in France and Europe: - the consideration by political bodies of this option that contributes to reducing greenhouse gas emissions, - the first industrial operations worldwide, - the new European demonstration projects in Europe to generate electricity and produce hydrogen or steam, - the mounting interest amongst France's industry outside the energy sector: steel sector, cement production, waste processing, bio-fuel production, - the most pertinent achievements and new research initiatives in Europe for CO 2 capture, transport and storage, - the appropriate regulations and legal framework as well as economic incentives for cutting the costs and increasing the commitments of States

Geological subsurface will contribute significantly to the implementation of the energy policy towards renewables in Germany

Science.gov (United States)

Martens, Sonja; Kühn, Michael

2015-04-01

The demands to exploit the geological subsurface are increasing. In addition to the traditional production of raw materials such as natural gas and petroleum, or potable groundwater extraction the underground will most likely also be used to implement the climate and energy policy objectives in the context of the energy transition to renewables. These include the storage of energy from renewable sources (e.g. hydrogen and methane), the use of geothermal energy and possibly the long-term storage of carbon dioxide to reduce the release of greenhouse gases into the atmosphere. The presentation addresses the question which realistic contribution can be expected from the geo-resource subsurface for the energy revolution, the detachment of fossil and nuclear fuels as well as the reduction of CO2 emissions. The study of Henning and Palzer [1] that models the energy balance of the electricity and heat sector including all renewable energy converters, storage components and loads for a future German energy system shows that provision with 100% renewables is economically feasible by 2050. Based on their work, our estimates underline that already in 2015 more than 100% of the required methane storage capacities therein are available and more than 100% of the heat pump demands might be covered by shallow and deep geothermal energy production in the future. In addition we show that a newly developed energy storage system [2-3] could be applied to store 20-60% of the surplus energy from renewables expected for 2050 with integrated gas storage of methane and CO2. [1] Henning H-M, Palzer A (2014) A comprehensive model for the German electricity and heat sector in a future energy system with a dominant contribution from renewable energy technologies -- Part I: Methodology. Renewable and Sustainable Energy Reviews 30, 1003-1018. doi: 10.1016/j.rser.2013.09.012 [2] Kühn M, Nakaten N, Streibel M, Kempka T (2014) CO2 geological storage and utilization for a carbon neutral "power

Inverse Problem for 3D coupled Flow-Geomechanics Models and Induced Seismicity: Application to Subsurface Characterization and Seismicity Forecasting in Geologic CO2 Storage

Science.gov (United States)

Castineira, D.; Jha, B.; Juanes, R.

2016-12-01

Carbon Capture and Sequestration (CCS) is regarded as a promising technology to mitigate rising CO2 concentrations in the atmosphere from industrial emissions. However, as a result of the inherent uncertainty that is present in geological structures, assessing the stability of geological faults and quantifying the potential for induced seismicity is a fundamental challenge for practical implementation of CCS. Here we present a formal framework for the solution of the inverse problem associated with coupled flow and geomechanics models of CO2 injection and subsurface storage. Our approach builds from the application of Gaussian Processes, MCMC and posterior predictive analysis to evaluate relevant earthquake attributes (earthquake time, location and magnitude) in 3D synthetic models of CO2 storage under geologic, observational and operational uncertainty. In our approach, we first conduct hundreds of simulations of a high-fidelity 3D computational model for CO2 injection into a deep saline aquifer, dominated by an anticline structure and a fault. This ensemble of realizations accounts for uncertainty in the model parameters (including fault geomechanical and rock properties) and observations (earthquake time, location and magnitude). We apply Gaussian processes (GP) to generate a valid surrogate that closely approximates the behavior of the high fidelity (and computationally intensive) model, and apply hyperparameter optimization and cross-validation techniques in the solution of this multidimensional data-fit problem. The net result of this process is the generation of a fast model that can be effectively used for Bayesian analysis. We then implement Markov chain Monte Carlo (MCMC) to determine the posterior distribution of the model uncertain parameters (given some prior distributions for those parameters and given the likelihood defined in this case by the GP model). Our results show that the resulting posterior distributions correctly converge towards the "true

European resource assessment for geothermal energy and CO2 storage

NARCIS (Netherlands)

Wees, J.D. van; Neele, F.

2013-01-01

Geothermal Energy and CO2 Capture and Storage (CCS) are both considered major contributors to the global energy transition. Their success critically depends on subsurface resource quality, which in turn depends on specific subsurface parameters. For CCS and Geothermal Energy these in some respect

Synthetic seismic monitoring using reverse-time migration and Kirchhoff migration for CO2 sequestration in Korea

Science.gov (United States)

Kim, W.; Kim, Y.; Min, D.; Oh, J.; Huh, C.; Kang, S.

2012-12-01

During last two decades, CO2 sequestration in the subsurface has been extensively studied and progressed as a direct tool to reduce CO2 emission. Commercial projects such as Sleipner, In Salah and Weyburn that inject more than one million tons of CO2 per year are operated actively as well as test projects such as Ketzin to study the behavior of CO2 and the monitoring techniques. Korea also began the CCS (CO2 capture and storage) project. One of the prospects for CO2 sequestration in Korea is the southwestern continental margin of Ulleung basin. To monitor the behavior of CO2 underground for the evaluation of stability and safety, several geophysical monitoring techniques should be applied. Among various geophysical monitoring techniques, seismic survey is considered as the most effective tool. To verify CO2 migration in the subsurface more effectively, seismic numerical simulation is an essential process. Furthermore, the efficiency of the seismic migration techniques should be investigated for various cases because numerical seismic simulation and migration test help us accurately interpret CO2 migration. In this study, we apply the reverse-time migration and Kirchhoff migration to synthetic seismic monitoring data generated for the simplified model based on the geological structures of Ulleung basin in Korea. Synthetic seismic monitoring data are generated for various cases of CO2 migration in the subsurface. From the seismic migration images, we can investigate CO2 diffusion patterns indirectly. From seismic monitoring simulation, it is noted that while the reverse-time migration generates clear subsurface images when subsurface structures are steeply dipping, Kirchhoff migration has an advantage in imaging horizontal-layered structures such as depositional sediments appearing in the continental shelf. The reverse-time migration and Kirchhoff migration present reliable subsurface images for the potential site characterized by stratigraphical traps. In case of

Subsurface low pH and carbonate saturation state of aragonite on China side of the North Yellow Sea: combined effects of global atmospheric CO2 increase, regional environmental changes, and local biogeochemical processes

Science.gov (United States)

Zhai, W.-D.; Zheng, N.; Huo, C.; Xu, Y.; Zhao, H.-D.; Li, Y.-W.; Zang, K.-P.; Wang, J.-Y.; Xu, X.-M.

2013-02-01

Based upon seven field surveys conducted between May 2011 and January 2012, we investigated pH, carbonate saturation state of aragonite (Ωarag), and ancillary parameters on the Chinese side of the North Yellow Sea, a western North Pacific continental margin of major economic importance. Subsurface waters were nearly in equilibrium with air in May and June. From July to October, the fugacity of CO2 (fCO2) of bottom water gradually increased to 697 ± 103 μatm and pH decreased to 7.83 ± 0.07 due to respiration/remineralization processes of primary production induced biogenic particles. In November and January, bottom water fCO2 decreased and pH gradually returned to an air-equilibrated level due to cooling enhanced vertical mixing. The corresponding bottom water Ωarag was 1.74 ± 0.17 (May), 1.77 ± 0.26 (June), 1.70 ± 0.26 (July), 1.72 ± 0.33 (August), 1.32 ± 0.31 (October), 1.50 ± 0.28 (November), and 1.41 ± 0.12 (January). Critically low Ωarag values of 1.0 to 1.2 were mainly observed in subsurface waters in a salinity range of 31.5-32.5 psu in October and November, accounting for ~ 10% of the North Yellow Sea area. Water mass derived from the adjacent Bohai Sea had a typical water salinity of 30.5-31.5 psu, and bottom water Ωarag values ranged mostly between 1.6 and 2.4. This study showed that the carbonate system in the North Yellow Sea was substantially influenced by global atmospheric CO2 increase. The community respiration/remineralization rates in typical North Yellow Sea bottom water mass were estimated at 0.55-1.0 μmol O2 kg-1 d-1 in warm seasons, leading to seasonal drops in subsurface pH and Ωarag. Outflow of the Bohai Sea water mass counteracted the subsurface Ωarag reduction in the North Yellow Sea.

ESTIMATION OF NEAR SUBSURFACE COAL FIRE GAS EMISSIONS BASED ON GEOPHYSICAL INVESTIGATIONS

Science.gov (United States)

Chen-Brauchler, D.; Meyer, U.; Schlömer, S.; Kus, J.; Gundelach, V.; Wuttke, M.; Fischer, C.; Rueter, H.

2009-12-01

Spontaneous and industrially caused subsurface coal fires are worldwide disasters that destroy coal resources, cause air pollution and emit a large amount of green house gases. Especially in developing countries, such as China, India and Malaysia, this problem has intensified over the last 15 years. In China alone, 10 to 20 million tons of coal are believed to be lost in uncontrolled coal fires. The cooperation of developing countries and industrialized countries is needed to enforce internationally concerted approaches and political attention towards the problem. The Clean Development Mechanism (CDM) under the framework of the Kyoto Protocol may provide an international stage for financial investment needed to fight the disastrous situation. A Sino-German research project for coal fire exploration, monitoring and extinction applied several geophysical approaches in order to estimate the annual baseline especially of CO2 emissions from near subsurface coal fires. As a result of this project, we present verifiable methodologies that may be used in the CDM framework to estimate the amount of CO2 emissions from near subsurface coal fires. We developed three possibilities to approach the estimation based on (1) thermal energy release, (2) geological and geometrical determinations as well as (3) direct gas measurement. The studies involve the investigation of the physical property changes of the coal seam and bedrock during different burning stages of a underground coal fire. Various geophysical monitoring methods were applied from near surface to determine the coal volume, fire propagation, temperature anomalies, etc.

Review of the impacts of leaking CO 2 gas and brine on groundwater quality

Energy Technology Data Exchange (ETDEWEB)

Qafoku, Nikolla P.; Lawter, Amanda R.; Bacon, Diana H.; Zheng, Liange; Kyle, Jennifer; Brown, Christopher F.

2017-06-01

This review paper provides a synthetic view of the existing knowledge and summarizes data and findings of the recent literature on the subject of the potential leaking of CO2 from the deep subsurface storage reservoirs and the effects on aquifer quality. New ideas and concepts are developed and insights are also provided. The objectives of this paper are to: 1) present and discuss potential risks for groundwater degradation due to CO2 gas and brine exposure; 2) identify the set of geochemical data required to assess and predict aquifer responses to CO2 and brine leakage. Specifically, this paper will discuss the following issues: 1) Aquifer responses (such as changes in aqueous phase/groundwater chemical composition; changes in solid phase chemistry and mineralogy; changes in the extent and rate of reactions and processes and possible establishment of a new network of reactions and processes affecting or controlling overall mobility of major, minor, and trace elements; development of conceptual and reduced order models (ROMs) to describe and predict aquifer responses); 2) The degree of impact such as significant or insignificant changes in pH and major, minor, and trace element release that depend on the following controlling variables; the effect of leaking plume characteristics (gas composition, pure CO2 and/or CO2 -CH4 -H2S mixtures and brine concentration and composition (trace metals); aquifer properties [such as initial aqueous phase conditions and mineralogy: minerals controlling sediments’ response (e.g., calcite, Si bearing minerals, etc.)]; overview of relevant hydrogeological and geochemical processes related to the impact of CO2 gas and brine on groundwater quality; the fate of the elements released from sediments or transported with brine (such as precipitation/incorporation into minerals (calcite and other minerals), adsorption, electron transfer reactions, the role of natural attenuation; whether or not the release of metals following exposure to

Integrated Surface/subsurface flow modeling in PFLOTRAN

Energy Technology Data Exchange (ETDEWEB)

Painter, Scott L [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2016-10-01

Understanding soil water, groundwater, and shallow surface water dynamics as an integrated hydrological system is critical for understanding the Earth’s critical zone, the thin outer layer at our planet’s surface where vegetation, soil, rock, and gases interact to regulate the environment. Computational tools that take this view of soil moisture and shallow surface flows as a single integrated system are typically referred to as integrated surface/subsurface hydrology models. We extend the open-source, highly parallel, subsurface flow and reactive transport simulator PFLOTRAN to accommodate surface flows. In contrast to most previous implementations, we do not represent a distinct surface system. Instead, the vertical gradient in hydraulic head at the land surface is neglected, which allows the surface flow system to be eliminated and incorporated directly into the subsurface system. This tight coupling approach leads to a robust capability and also greatly simplifies implementation in existing subsurface simulators such as PFLOTRAN. Successful comparisons to independent numerical solutions build confidence in the approximation and implementation. Example simulations of the Walker Branch and East Fork Poplar Creek watersheds near Oak Ridge, Tennessee demonstrate the robustness of the approach in geometrically complex applications. The lack of a robust integrated surface/subsurface hydrology capability had been a barrier to PFLOTRAN’s use in critical zone studies. This work addresses that capability gap, thus enabling PFLOTRAN as a community platform for building integrated models of the critical zone.

Seaweed fails to prevent ocean acidification impact on foraminifera along a shallow-water CO2 gradient.

Science.gov (United States)

Pettit, Laura R; Smart, Christopher W; Hart, Malcolm B; Milazzo, Marco; Hall-Spencer, Jason M

2015-05-01

Ocean acidification causes biodiversity loss, alters ecosystems, and may impact food security, as shells of small organisms dissolve easily in corrosive waters. There is a suggestion that photosynthetic organisms could mitigate ocean acidification on a local scale, through seagrass protection or seaweed cultivation, as net ecosystem organic production raises the saturation state of calcium carbonate making seawater less corrosive. Here, we used a natural gradient in calcium carbonate saturation, caused by shallow-water CO2 seeps in the Mediterranean Sea, to assess whether seaweed that is resistant to acidification (Padina pavonica) could prevent adverse effects of acidification on epiphytic foraminifera. We found a reduction in the number of species of foraminifera as calcium carbonate saturation state fell and that the assemblage shifted from one dominated by calcareous species at reference sites (pH ∼8.19) to one dominated by agglutinated foraminifera at elevated levels of CO2 (pH ∼7.71). It is expected that ocean acidification will result in changes in foraminiferal assemblage composition and agglutinated forms may become more prevalent. Although Padina did not prevent adverse effects of ocean acidification, high biomass stands of seagrass or seaweed farms might be more successful in protecting epiphytic foraminifera.

GIS based 3D visualization of subsurface and surface lineaments / faults and their geological significance, northern tamil nadu, India

Science.gov (United States)

Saravanavel, J.; Ramasamy, S. M.

2014-11-01

The study area falls in the southern part of the Indian Peninsular comprising hard crystalline rocks of Archaeozoic and Proterozoic Era. In the present study, the GIS based 3D visualizations of gravity, magnetic, resistivity and topographic datasets were made and therefrom the basement lineaments, shallow subsurface lineaments and surface lineaments/faults were interpreted. These lineaments were classified as category-1 i.e. exclusively surface lineaments, category-2 i.e. surface lineaments having connectivity with shallow subsurface lineaments and category-3 i.e. surface lineaments having connectivity with shallow subsurface lineaments and basement lineaments. These three classified lineaments were analyzed in conjunction with known mineral occurrences and historical seismicity of the study area in GIS environment. The study revealed that the category-3 NNE-SSW to NE-SW lineaments have greater control over the mineral occurrences and the N-S, NNE-SSW and NE-SW, faults/lineaments control the seismicities in the study area.

Large CO2 and CH4 release from a flooded formerly drained fen

Science.gov (United States)

Sachs, T.; Franz, D.; Koebsch, F.; Larmanou, E.; Augustin, J.

2016-12-01

Drained peatlands are usually strong carbon dioxide (CO2) sources. In Germany, up to 4.5 % of the national CO2 emissions are estimated to be released from agriculturally used peatlands and for some peatland-rich northern states, such as Mecklenburg-Western Pomerania, this share increases to about 20%. Reducing this CO2 source and restoring the peatlands' natural carbon sink is one objective of large-scale nature protection and restoration measures, in which 37.000 ha of drained and degraded peatlands in Mecklenburg-Western Pomerania are slated for rewetting. It is well known, however, that in the initial phase of rewetting, a reduction of the CO2 source strength is usually accompanied by an increase in CH4 emissions. Thus, whether and when the intended effects of rewetting with regard to greenhouse gases are achieved, depends on the balance of CO2 and CH4 fluxes and on the duration of the initial CH4 emission phase. In 2013, a new Fluxnet site went online at a flooded formerly drained river valley fen site near Zarnekow, NE Germany (DE-Zrk), to investigate the combined CO2 and CH4 dynamics at such a heavily degraded and rewetted peatland. The site is dominated by open water with submerged and floating vegetation and surrounding Typha latifolia.Nine year after rewetting, we found large CH4 emissions of 53 g CH4 m-2 a-1 from the open water area, which are 4-fold higher than from the surrounding vegetation zone (13 g CH4 m-2 a-1). Surprisingly, both the open water and the vegetated area were net CO2 sources of 158 and 750 g CO2 m-2 a-1, respectively. Unusual meteorological conditions with a warm and dry summer and a mild winter might have facilitated high respiration rates, particularly from temporally non-inundated organic mud in the vegetation zone.

Soil organic carbon and nitrogen pools drive soil C-CO2 emissions from selected soils in Maritime Antarctica.

Science.gov (United States)

Pires, C V; Schaefer, C E R G; Hashigushi, A K; Thomazini, A; Filho, E I F; Mendonça, E S

2017-10-15

The ongoing trend of increasing air temperatures will potentially affect soil organic matter (SOM) turnover and soil C-CO 2 emissions in terrestrial ecosystems of Maritime Antarctica. The effects of SOM quality on this process remain little explored. We evaluated (i) the quantity and quality of soil organic matter and (ii) the potential of C release through CO 2 emissions in lab conditions in different soil types from Maritime Antarctica. Soil samples (0-10 and 10-20cm) were collected in Keller Peninsula and the vicinity of Arctowski station, to determine the quantity and quality of organic matter and the potential to emit CO 2 under different temperature scenarios (2, 5, 8 and 11°C) in lab. Soil organic matter mineralization is low, especially in soils with low organic C and N contents. Recalcitrant C form is predominant, especially in the passive pool, which is correlated with humic substances. Ornithogenic soils had greater C and N contents (reaching to 43.15gkg -1 and 5.22gkg -1 for total organic carbon and nitrogen, respectively). C and N were more present in the humic acid fraction. Lowest C mineralization was recorded from shallow soils on basaltic/andesites. C mineralization rates at 2°C were significant lower than at higher temperatures. Ornithogenic soils presented the lowest values of C-CO 2 mineralized by g of C. On the other hand, shallow soils on basaltic/andesites were the most sensitive sites to emit C-CO 2 by g of C. With permafrost degradation, soils on basaltic/andesites and sulfates are expected to release more C-CO 2 than ornithogenic soils. With greater clay contents, more protection was afforded to soil organic matter, with lower microbial activity and mineralization. The trend of soil temperature increases will favor C-CO 2 emissions, especially in the reduced pool of C stored and protected on permafrost, or in occasional Histosols. Copyright © 2016 Elsevier B.V. All rights reserved.

Source strength and dispersion of CO2 releases from high-pressure pipelines: CFD model using real gas equation of state

International Nuclear Information System (INIS)

Liu, Xiong; Godbole, Ajit; Lu, Cheng; Michal, Guillaume; Venton, Philip

2014-01-01

Highlights: • Validated CFD models for decompression and dispersion of CO 2 releases from pipelines. • Incorporation of real gas EOS into CFD code for source strength estimation. • Demonstration of better performance of SST k–ω turbulence model for jet flow. • Demonstration of better performance of real gas EOS compared to ideal gas EOS. • Demonstration of superiority of CFD models over a commercial risk assessment package. - Abstract: Transportation of CO 2 in high-pressure pipelines forms a crucial link in the ever-increasing application of Carbon Capture and Storage (CCS) technologies. An unplanned release of CO 2 from a pipeline presents a risk to human and animal populations and the environment. Therefore it is very important to develop a deeper understanding of the atmospheric dispersion of CO 2 before the deployment of CO 2 pipelines, to allow the appropriate safety precautions to be taken. This paper presents a two-stage Computational Fluid Dynamics (CFD) study developed (1) to estimate the source strength, and (2) to simulate the subsequent dispersion of CO 2 in the atmosphere, using the source strength estimated in stage (1). The Peng–Robinson (PR) EOS was incorporated into the CFD code. This enabled accurate modelling of the CO 2 jet to achieve more precise source strength estimates. The two-stage simulation approach also resulted in a reduction in the overall computing time. The CFD models were validated against experimental results from the British Petroleum (BP) CO 2 dispersion trials, and also against results produced by the risk management package Phast. Compared with the measurements, the CFD simulation results showed good agreement in both source strength and dispersion profile predictions. Furthermore, the effect of release direction on the dispersion was studied. The presented research provides a viable method for the assessment of risks associated with CCS

Subsurface microbial habitats on Mars

Science.gov (United States)

Boston, P. J.; Mckay, C. P.

1991-01-01

We developed scenarios for shallow and deep subsurface cryptic niches for microbial life on Mars. Such habitats could have considerably prolonged the persistence of life on Mars as surface conditions became increasingly inhospitable. The scenarios rely on geothermal hot spots existing below the near or deep subsurface of Mars. Recent advances in the comparatively new field of deep subsurface microbiology have revealed previously unsuspected rich aerobic and anaerobic microbal communities far below the surface of the Earth. Such habitats, protected from the grim surface conditions on Mars, could receive warmth from below and maintain water in its liquid state. In addition, geothermally or volcanically reduced gases percolating from below through a microbiologically active zone could provide the reducing power needed for a closed or semi-closed microbial ecosystem to thrive.

CO2 geosequestration at the laboratory scale: Combined geophysical and hydromechanical assessment of weakly-cemented shallow Sleipner-like reservoirs

Science.gov (United States)

Falcon-Suarez, I.; North, L. J.; Best, A. I.

2017-12-01

To date, the most promising mitigation strategy for reducing global carbon emissions is Carbon Capture and Storage (CCS). The storage technology (i.e., CO2 geosequestration, CGS) consists of injecting CO2 into deep geological formations, specifically selected for such massive-scale storage. To guarantee the mechanical stability of the reservoir during and after injection, it is crucial to improve existing monitoring techniques for controlling CGS activities. We developed a comprehensive experimental program to investigate the integrity of the Sleipner CO2 storage site in the North Sea - the first commercial CCS project in history where 1 Mtn/y of CO2 has been injected since 1996. We assessed hydro-mechanical effects and the related geophysical signatures of three synthetic sandstones and samples from the Utsira Sand formation (main reservoir at Sleipner), at realistic pressure-temperature (PT) conditions and fluid compositions. Our experimental approach consists of brine-CO2 flow-through tests simulating variable inflation/depletion scenarios, performed in the CGS-rig (Fig. 1; Falcon-Suarez et al., 2017) at the National Oceanography Centre (NOC) in Southampton. The rig is designed for simultaneous monitoring of ultrasonic P- and S-wave velocities and attenuations, electrical resistivity, axial and radial strains, pore pressure and flow, during the co-injection of up to two fluids under controlled PT conditions. Our results show velocity-resistivity and seismic-geomechanical relations of practical importance for the distinction between pore pressure and pore fluid distribution during CGS activities. By combining geophysical and thermo-hydro-mechano-chemical coupled information, we can provide laboratory datasets that complement in situ seismic, geomechanical and electrical survey information, useful for the CO2 plume monitoring in Sleipner site and other shallow weakly-cemented sand CCS reservoirs. Falcon-Suarez, I., Marín-Moreno, H., Browning, F., Lichtschlag, A

Assessment of CO2 discharge in a spring using time-variant stable carbon isotope data as a natural analogue study of CO2 leakage

Science.gov (United States)

Yu, Soonyoung; Chae, Gitak; Jo, Minki; Kim, Jeong-Chan; Yun, Seong-Taek

2015-04-01

CO2-rich springs have been studied as a natural analogue of CO2 leakage through shallow subsurface environment, as they provide information on the behaviors of CO2 during the leakage from geologic CO2 storage sites. For this study, we monitored the δ13C values as well as temperature, pH, EC, DO, and alkalinity for a CO2-rich spring for 48 hours. The water samples (N=47) were collected every hour in stopper bottles without headspace to avoid the interaction with air and the CO2 degassing. The δ13C values of total dissolved inorganic carbon (TDIC) in the water samples were analyzed using a cavity ring-down spectroscopy (CRDS) system (Picarro). The values of δ13CTDIC, temperature, pH, EC, DO, and alkalinity were in the range of -9.43 ~ -8.91 o 12.3 ~ 13.2oC, 4.86 ~ 5.02, 186 ~ 189 μS/cm, 1.8 ~ 3.4 mg/L, and 0.74 ~ 0.95 meq/L, respectively. The concentrations of TDIC calculated using pH and alkalinity values were between 22.5 and 34.8 mmol/L. The δ13CTDIC data imply that dissolved carbon in the spring was derived from a deep-seated source (i.e., magmatic) that was slightly intermixed with soil CO2. Careful examination of the time-series variation of measured parameters shows the following characteristics: 1) the δ13CTDIC values are negatively correlated with pH (r = -0.59) and positively correlated with TDIC (r = 0.58), and 2) delay times of the change of pH and alkalinity following the change of δ13CTDIC values are 0 and -3 hours, respectively; the pH change occurs simultaneously with the change of δ13CTDIC, while the alkalinity change happens before 3 hours. Our results indicate that the studied CO2-rich spring is influenced by the intermittent supply of deep-seated CO2. [Acknowledgment] This work was financially supported by the fundamental research project of KIGAM and partially by the "Geo-Advanced Innovative Action (GAIA) Project (2014000530003)" from Korea Ministry of Environment (MOE).

Development of thermosensitive poly(n-isopropylacrylamide-co-((2-dimethylamino) ethyl methacrylate))-based nanoparticles for controlled drug release

Energy Technology Data Exchange (ETDEWEB)

Peng, Cheng-Liang; Luo, Tsai-Yueh; Lin, Wuu-Jyh [Isotope Application Division, Institute of Nuclear Energy Research, PO Box 3-27, Longtan Taoyuan 325, Taiwan (China); Tsai, Han-Min; Yang, Shu-Jyuan; Lin, Chia-Fu; Shieh, Ming-Jium, E-mail: soloman@ntu.edu.tw [Institute of Biomedical Engineering, College of Medicine and College of Engineering, National Taiwan University, No 1, Section 1, Jen-Ai Road, Taipei 10051, Taiwan (China)

2011-07-01

Thermosensitive nanoparticles based on poly(N-isopropylacrylamide-co-((2-dimethylamino)ethylmethacrylate)) (poly(NIPA-co-DMAEMA)) copolymers were successfully fabricated by free radical polymerization. The lower critical solution temperature (LCST) of the synthesized nanoparticles was 41 deg. C and a temperature above which would cause the nanoparticles to undergo a volume phase transition from 140 to 100 nm, which could result in the expulsion of encapsulated drugs. Therefore, we used the poly(NIPA-co-DMAEMA) nanoparticles as a carrier for the controlled release of a hydrophobic anticancer agent, 7-ethyl-10-hydroxy-camptothecin (SN-38). The encapsulation efficiency and loading content of SN-38-loaded nanoparticles at an SN-38/poly(NIPA-co-DMAEMA) ratio of 1/10 (D/P = 1/10) were about 80% and 6.293%, respectively. Moreover, the release profile of SN-38-loaded nanoparticles revealed that the release rate at 42 deg. C (above LCST) was higher than that at 37 deg. C (below LCST), which demonstrated that the release of SN-38 could be controlled by increasing the temperature. The cytotoxicity of the SN-38-loaded poly(NIPA-co-DMAEMA) nanoparticles was investigated in human colon cancer cells (HT-29) to compare with the treatment of an anticancer drug, Irinotecan (CPT-11). The antitumor efficacy evaluated in a C26 murine colon tumor model showed that the SN-38-loaded nanoparticles in combination with hyperthermia therapy efficiently suppressed tumor growth. The results indicate that these thermo-responsive nanoparticles are potential carriers for controlled drug delivery.

Development of a comprehensive source term model for the Subsurface Disposal Area at the Idaho National Engineering and Environmental Laboratory

International Nuclear Information System (INIS)

1997-01-01

The first detailed comprehensive simulation study to evaluate fate and transport of wastes disposed in the Subsurface Disposal Area (SDA), at the Radioactive Waste Management Complex (RWMC), Idaho National Engineering and Environmental Laboratory (INEEL) has recently been conducted. One of the most crucial parts of this modeling was the source term or release model. The current study used information collected over the last five years defining contaminant specific information including: the amount disposed, the waste form (physical and chemical properties) and the type of container used for each contaminant disposed. This information was used to simulate the release of contaminants disposed in the shallow subsurface at the SDA. The DUST-MS model was used to simulate the release. Modifications were made to allow the yearly disposal information to be incorporated. The modeling includes unique container and release rate information for each of the 42 years of disposal. The results from this simulation effort are used for both a groundwater and a biotic uptake evaluation. As part of this modeling exercise, inadequacies in the available data relating to the release of contaminants have been identified. The results from this modeling study have been used to guide additional data collection activities at the SDA for purposes of increasing confidence in the appropriateness of model predictions

[Impacts of rice straw biochar on organic carbon and CO2 release in arable soil].

Science.gov (United States)

Ke, Yue-Jin; Hu, Xue-Yu; Yi, Qing; Yu, Zhong

2014-01-01

In order to investigate the stability of biochar and the effect of biochar when added into soil on soil organic carbon, a 130-day incubation experiment was conducted with rice straw biochar produced at 500 degrees C and 700 degrees C (RBC500 and RBC700) and with addition rates of 0% (control), 3%, 6% and 100% (pure biochar), to detect the change of total organic carbon (TOC), easily oxidized carbon (EOC) and status of CO2 release, following addition of biochar in arable soil. Results showed that: the content of both TOC and EOC in soil increased with biochar addition rates comparing with the control. RBC500 had greater contributions to both TOC and EOC increasing amounts than those of RBC700 under the same biochar addition rate. TOC contents of all treatments decreased during the initial 30 days with the largest decreasing amplitude of 15.8%, and tended to be stable in late incubation stages. Same to that of TOC, EOC contents of all treatments also tended to remain stable after 30 days, but in the 30 days of early incubation, EOC in the soil decreased by 72.4% and 81.7% respectively when the added amount of RBC500 was 3% and 6% , while it was reduced by 61.3% and 69.8% respectively when the added amount of RBC700 was 3% and 6%. EOC contents of soil added with biochar produced at the same temperature were similar in the end of incubation. The reduction of soil EOC content in early incubation may be related to mineralization caused by labile fractions of biochar. During the 130-day incubation, the accumulated CO2 releases showed an order of soil and biochar mixtures soil could reduce CO2 release, the largest reduction amplitude is 41.05%. In a long time scale, biochar as a soil amendment is favorable to the deduction of greenhouse gas release and soil carbon immobilization. Biochar could be used as a soil carbon sequestration carrier.

CO2 cycle

Science.gov (United States)

Titus, Timothy N.; Byrne, Shane; Colaprete, Anthony; Forget, Francois; Michaels, Timothy I.; Prettyman, Thomas H.

2017-01-01

This chapter discusses the use of models, observations, and laboratory experiments to understand the cycling of CO2 between the atmosphere and seasonal Martian polar caps. This cycle is primarily controlled by the polar heat budget, and thus the emphasis here is on its components, including solar and infrared radiation, the effect of clouds (water- and CO2-ice), atmospheric transport, and subsurface heat conduction. There is a discussion about cap properties including growth and regression rates, albedos and emissivities, grain sizes and dust and/or water-ice contamination, and curious features like cold gas jets and araneiform (spider-shaped) terrain. The nature of the residual south polar cap is discussed as well as its long-term stability and ability to buffer atmospheric pressures. There is also a discussion of the consequences of the CO2 cycle as revealed by the non-condensable gas enrichment observed by Odyssey and modeled by various groups.

Modeling and Evaluation of Geophysical Methods for Monitoring and Tracking CO2 Migration

Energy Technology Data Exchange (ETDEWEB)

Daniels, Jeff

2012-11-30

Geological sequestration has been proposed as a viable option for mitigating the vast amount of CO{sub 2} being released into the atmosphere daily. Test sites for CO{sub 2} injection have been appearing across the world to ascertain the feasibility of capturing and sequestering carbon dioxide. A major concern with full scale implementation is monitoring and verifying the permanence of injected CO{sub 2}. Geophysical methods, an exploration industry standard, are non-invasive imaging techniques that can be implemented to address that concern. Geophysical methods, seismic and electromagnetic, play a crucial role in monitoring the subsurface pre- and post-injection. Seismic techniques have been the most popular but electromagnetic methods are gaining interest. The primary goal of this project was to develop a new geophysical tool, a software program called GphyzCO2, to investigate the implementation of geophysical monitoring for detecting injected CO{sub 2} at test sites. The GphyzCO2 software consists of interconnected programs that encompass well logging, seismic, and electromagnetic methods. The software enables users to design and execute 3D surface-to-surface (conventional surface seismic) and borehole-to-borehole (cross-hole seismic and electromagnetic methods) numerical modeling surveys. The generalized flow of the program begins with building a complex 3D subsurface geological model, assigning properties to the models that mimic a potential CO{sub 2} injection site, numerically forward model a geophysical survey, and analyze the results. A test site located in Warren County, Ohio was selected as the test site for the full implementation of GphyzCO2. Specific interest was placed on a potential reservoir target, the Mount Simon Sandstone, and cap rock, the Eau Claire Formation. Analysis of the test site included well log data, physical property measurements (porosity), core sample resistivity measurements, calculating electrical permittivity values, seismic data

Quantification of exploitable shallow geothermal energy by using Borehole Heat Exchanger coupled Ground Source Heat Pump systems

International Nuclear Information System (INIS)

Hein, Philipp; Zhu, Ke; Bucher, Anke; Kolditz, Olaf; Pang, Zhonghe; Shao, Haibing

2016-01-01

Highlights: • The amount of technically exploitable shallow geothermal energy was quantified. • Therefore, a comprehensive numerical borehole heat exchanger model was employed. • The concept of equivalent temperature drop is introduced. • For one BHE, an equivalent temperature drop of 1.8–2.8 °C over 30 years is realistic • The average extractable energy amount evaluates to be 3.5–5.4 kW h m"−"2 a"−"1. - Abstract: In previous studies, the amount of exploitable shallow geothermal energy was estimated by assuming a uniform temperature drop of 2–6 °C in the aquifer. In this work, a more comprehensive numerical model has been employed to evaluate the available amount of shallow geothermal energy by using Borehole Heat Exchanger coupled Ground Source Heat Pump systems. Numerical experiments have been performed by simulating the long-term evolution of the subsurface temperature field, which is subject to the operation of borehole heat exchangers and varying parameters like subsurface thermal conductivity and groundwater flow velocity. The concept of equivalent temperature drop is proposed as an auxiliary quantity for the subsurface. With the help of this parameter, a procedure has been established to quantify the amount of shallow geothermal potential. Following this approach, a realistic equivalent temperature reduction is found to be from −1.8 to −4.4 °C in the subsurface over a period of 30 years. This can be translated to an annual extractable geothermal energy value in a unit surface area, and it ranges from 3.5 to 8.6 kW h m"−"2 a"−"1. The exact value is site specific and heavily depends on the soil thermal conductivity, groundwater velocity, and borehole arrangement.

Integrated geomechanical modelling at TNO for assessement of deep subsurface risks

NARCIS (Netherlands)

Orlic, B.; Fokker, P.; Zijl, W.; Scheffers, B.

2001-01-01

Public authorities, E & P and the mining industry increasingly demand fundamental insight and accurate predictions on subsurface and surface deformation and damage due to exploitation of subsurface natural resources, and subsurface storage of energy residues (e.g. CO2). At this moment deformation is

Subsurface urban heat islands in German cities.

Science.gov (United States)

Menberg, Kathrin; Bayer, Peter; Zosseder, Kai; Rumohr, Sven; Blum, Philipp

2013-01-01

Little is known about the intensity and extension of subsurface urban heat islands (UHI), and the individual role of the driving factors has not been revealed either. In this study, we compare groundwater temperatures in shallow aquifers beneath six German cities of different size (Berlin, Munich, Cologne, Frankfurt, Karlsruhe and Darmstadt). It is revealed that hotspots of up to +20K often exist, which stem from very local heat sources, such as insufficiently insulated power plants, landfills or open geothermal systems. When visualizing the regional conditions in isotherm maps, mostly a concentric picture is found with the highest temperatures in the city centers. This reflects the long-term accumulation of thermal energy over several centuries and the interplay of various factors, particularly in heat loss from basements, elevated ground surface temperatures (GST) and subsurface infrastructure. As a primary indicator to quantify and compare large-scale UHI intensity the 10-90%-quantile range UHII(10-90) of the temperature distribution is introduced. The latter reveals, in comparison to annual atmospheric UHI intensities, an even more pronounced heating of the shallow subsurface. Copyright © 2012 Elsevier B.V. All rights reserved.

A hybrid geothermal energy conversion technology: Auxiliary heating of geothermally preheated water or CO2 - a potential solution for low-temperature resources

Science.gov (United States)

Saar, Martin; Garapati, Nagasree; Adams, Benjamin; Randolph, Jimmy; Kuehn, Thomas

2016-04-01

Safe, sustainable, and economic development of deep geothermal resources, particularly in less favourable regions, often requires employment of unconventional geothermal energy extraction and utilization methods. Often "unconventional geothermal methods" is synonymously and solely used as meaning enhanced geothermal systems, where the permeability of hot, dry rock with naturally low permeability at greater depths (4-6 km), is enhanced. Here we present an alternative unconventional geothermal energy utilization approach that uses low-temperature regions that are shallower, thereby drastically reducing drilling costs. While not a pure geothermal energy system, this hybrid approach may enable utilization of geothermal energy in many regions worldwide that can otherwise not be used for geothermal electricity generation, thereby increasing the global geothermal resource base. Moreover, in some realizations of this hybrid approach that generate carbon dioxide (CO2), the technology may be combined with carbon dioxide capture and storage (CCS) and CO2-based geothermal energy utilization, resulting in a high-efficiency (hybrid) geothermal power plant with a negative carbon footprint. Typically, low- to moderate-temperature geothermal resources are more effectively used for direct heat energy applications. However, due to high thermal losses during transport, direct use requires that the heat resource is located near the user. Alternatively, we show here that if such a low-temperature geothermal resource is combined with an additional or secondary energy resource, the power production is increased compared to the sum from two separate (geothermal and secondary fuel) power plants (DiPippo et al. 1978) and the thermal losses are minimized because the thermal energy is utilized where it is produced. Since Adams et al. (2015) found that using CO2 as a subsurface working fluid produces more net power than brine at low- to moderate-temperature geothermal resource conditions, we

An Evaluation of Subsurface Microbial Activity Conditional to Subsurface Temperature, Porosity, and Permeability at North American Carbon Sequestration Sites

Energy Technology Data Exchange (ETDEWEB)

Wilson, B. [Oak Ridge Inst. for Science and Education (ORISE), Oak Ridge, TN (United States); National Energy Technology Lab. (NETL), Albany, OR (United States); Mordensky, S. [Oak Ridge Inst. for Science and Education (ORISE), Oak Ridge, TN (United States); National Energy Technology Lab. (NETL), Albany, OR (United States); Verba, Circe [National Energy Technology Lab. (NETL), Albany, OR (United States); Rabjohns, K. [Oak Ridge Inst. for Science and Education (ORISE), Oak Ridge, TN (United States); National Energy Technology Lab. (NETL), Albany, OR (United States); Colwell, F. [National Energy Technology Lab. (NETL), Albany, OR (United States); Oregon State Univ., Corvallis, OR (United States). College of Earth, Ocean, and Atmospheric Sciences

2016-06-21

Several nations, including the United States, recognize global climate change as a force transforming the global ecosphere. Carbon dioxide (CO₂) is a greenhouse gas that contributes to the evolving climate. Reduction of atmospheric CO₂ levels is a goal for many nations and carbon sequestration which traps CO₂ in the Earth’s subsurface is one method to reduce atmospheric CO₂ levels. Among the variables that must be considered in developing this technology to a national scale is microbial activity. Microbial activity or biomass can change rock permeability, alter artificial seals around boreholes, and play a key role in biogeochemistry and accordingly may determine how CO₂ is sequestered underground. Certain physical parameters of a reservoir found in literature (e.g., temperature, porosity, and permeability) may indicate whether a reservoir can host microbial communities. In order to estimate which subsurface formations may host microbes, this report examines the subsurface temperature, porosity, and permeability of underground rock formations that have high potential to be targeted for CO₂ sequestration. Of the 268 North American wellbore locations from the National Carbon Sequestration Database (NATCARB; National Energy and Technology Laboratory, 2015) and 35 sites from Nelson and Kibler (2003), 96 sequestration sites contain temperature data. Of these 96 sites, 36 sites have temperatures that would be favorable for microbial survival, 48 sites have mixed conditions for supporting microbial populations, and 11 sites would appear to be unfavorable to support microbial populations. Future studies of microbe viability would benefit from a larger database with more formation parameters (e.g. mineralogy, structure, and groundwater chemistry), which would help to increase understanding of where CO₂ sequestration could be most efficiently implemented.

Evaluation through column leaching tests of metal release from contaminated estuarine sediment subject to CO2 leakages from Carbon Capture and Storage sites

International Nuclear Information System (INIS)

Payán, M. Cruz; Galan, Berta; Coz, Alberto; Vandecasteele, Carlo; Viguri, Javier R.

2012-01-01

The pH change and the release of organic matter and metals from sediment, due to the potential CO 2 acidified seawater leakages from a CCS (Carbon Capture and Storage) site are presented. Column leaching test is used to simulate a scenario where a flow of acidified seawater is in contact with recent contaminated sediment. The behavior of pH, dissolved organic carbon (DOC) and metals As, Cd, Cr, Cu, Ni, Pb, Zn, with liquid to solid (L/S) ratio and pH is analyzed. A stepwise strategy using empirical expressions and a geochemical model was conducted to fit experimental release concentrations. Despite the neutralization capacity of the seawater-carbonate rich sediment system, important acidification and releases are expected at local scale at lower pH. The obtained results would be relevant as a line of evidence input of CCS risk assessment, in an International context where strategies to mitigate the climate change would be applied. - Highlights: ► Tier structured approach for assessment of the release of metals from sediment. ► Standard column leaching test to simulate CO 2 acidified seawater CCS leakages. ► Metal and DOC release from marine sediment in contact to CO 2 acidified seawater. ► From empirical to geochemical modeling approaches of DOC and metals release in column tests. ► Contamination line of evidence input of CCS risk assessment. - Column metal release from CO 2 acidified seawater leakages in contact with estuarine contaminated sediment in CCS sites

Development of a calcium phosphate co-precipitate/poly(lactide-co-glycolide) DNA delivery system: release kinetics and cellular transfection studies.

Science.gov (United States)

Kofron, Michelle D; Laurencin, Cato T

2004-06-01

One of the most common non-viral methods for the introduction of foreign deoxyribonucleic acid (DNA) into cultured cells is calcium phosphate co-precipitate transfection. This technique involves the encapsulation of DNA within a calcium phosphate co-precipitate, particulate addition to in vitro cell culture, endocytosis of the co-precipitate, and exogenous DNA expression by the transfected cell. In this study, we fabricated a novel non-viral gene transfer system by adsorbing DNA, encapsulated in calcium phosphate (DNA/Ca-P) co-precipitates, to biodegradable two- and three-dimensional poly(lactide-co-glycolide) matrices (2D-DNA/Ca-P/PLAGA, 3D-DNA/Ca-P/PLAGA). Co-precipitate release studies demonstrated an initial burst release over the first 48 h. By day 7, approximately 96% of the initially adsorbed DNA/Ca-P co-precipitate had been released. This was followed by low levels of co-precipitate release for 42 days. Polymerase chain reaction was used to demonstrate the ability of the released DNA containing co-precipitates to transfect SaOS-2 cells cultured in vitro on the 3D-DNA/Ca-P/PLAGA matrix and maintenance of the structural integrity of the exogenous DNA. In summary, a promising system for the incorporation and controlled delivery of exogenous genes encapsulated within a calcium phosphate co-precipitate from biodegradable polymeric matrices has been developed and may have applicability to the delivery of therapeutic genes and the transfection of other cell types.

Auto Correlation Analysis of Coda Waves from Local Earthquakes for Detecting Temporal Changes in Shallow Subsurface Structures: the 2011 Tohoku-Oki, Japan Earthquake

Science.gov (United States)

Nakahara, Hisashi

2015-02-01

For monitoring temporal changes in subsurface structures I propose to use auto correlation functions of coda waves from local earthquakes recorded at surface receivers, which probably contain more body waves than surface waves. Use of coda waves requires earthquakes resulting in decreased time resolution for monitoring. Nonetheless, it may be possible to monitor subsurface structures in sufficient time resolutions in regions with high seismicity. In studying the 2011 Tohoku-Oki, Japan earthquake (Mw 9.0), for which velocity changes have been previously reported, I try to validate the method. KiK-net stations in northern Honshu are used in this analysis. For each moderate earthquake normalized auto correlation functions of surface records are stacked with respect to time windows in the S-wave coda. Aligning the stacked, normalized auto correlation functions with time, I search for changes in phases arrival times. The phases at lag times of <1 s are studied because changes at shallow depths are focused. Temporal variations in the arrival times are measured at the stations based on the stretching method. Clear phase delays are found to be associated with the mainshock and to gradually recover with time. The amounts of the phase delays are 10 % on average with the maximum of about 50 % at some stations. The deconvolution analysis using surface and subsurface records at the same stations is conducted for validation. The results show the phase delays from the deconvolution analysis are slightly smaller than those from the auto correlation analysis, which implies that the phases on the auto correlations are caused by larger velocity changes at shallower depths. The auto correlation analysis seems to have an accuracy of about several percent, which is much larger than methods using earthquake doublets and borehole array data. So this analysis might be applicable in detecting larger changes. In spite of these disadvantages, this analysis is still attractive because it can

Role of IL-1 beta and COX2 in silica-induced IL-6 release and loss of pneumocytes in co-cultures.

Science.gov (United States)

Herseth, Jan I; Refsnes, Magne; Låg, Marit; Schwarze, Per E

2009-10-01

The pro-inflammatory cytokines IL-1 beta, TNF-alpha and IL-6 are of great importance in the development of silica-induced lung damage and repair. In this study we investigated the role of IL-1 beta, TNF-alpha and COX2 in silica-induced regulation of IL-6 release and pneumocyte loss in various mono- and co-cultures of monocytes, pneumocytes and endothelial cells. All co-cultures with monocytes, and especially cultures including endothelial cells, showed an increase of silica-induced release of IL-6 compared to the respective monocultures. Treatment with the antagonist IL-1 ra strongly decreased IL-1 beta and IL-6 release in contact co-cultures of monocytes and pneumocytes. COX2 up-regulation by silica and IL-1 beta was eliminated by IL-1 ra. Inhibition of COX2 markedly reduced both IL-1 beta and IL-6 release. IL-1 ra was more effective than COX2-inhibition in reduction of IL-6, but not of IL-1 beta. Silica-induced pneumocyte loss was reduced by IL-1 beta, but this effect was not counteracted by the IL-1 receptor antagonist. Our findings suggest that silica-induced IL-6 release from pneumocytes is mainly mediated via IL-1 beta release from the monocytes, via both COX2-dependent and -independent pathways. Notably, COX2-derived mediators seem crucial for a positive feed-back regulation of IL-1 beta release from the monocytes. In contrast to silica-induced IL-6, the reduction in pneumocyte loss by IL-1 beta does not seem to be regulated through an IL-1R1-dependent mechanism.

Eddy Covariance Method for CO2 Emission Measurements: CCS Applications, Principles, Instrumentation and Software

Science.gov (United States)

Burba, George; Madsen, Rod; Feese, Kristin

2013-04-01

and technical papers. A free open-source software package with a user-friendly interface was developed accordingly for computing final fully corrected CO2 emission numbers [10]. The presentation covers highlights of the eddy covariance method, its application to geological carbon sequestration, key requirements, instrumentation and software, and reviews educational resources particularly useful for carbon sequestration research. References: [1] Aubinet, M., T. Vesala, and D. Papale (Eds.), 2012. Eddy Covariance: A Practical Guide to Measurement and Data Analysis. Springer-Verlag, 442 pp. [2] Foken T., 2008. Micrometeorology. Springer-Verlag, 308 pp. [4] Finley, R., 2009. An Assessment of Geological Carbon Sequestration in the Illinois Basin Overview of the Decatur-Illinois Basin Site. MGSC, http://www.istc.illinois.edu/info/govs_awards_docs/2009-GSA-1100-Finley.pdf [5] Liu, G. (Ed.), 2012. Greenhouse Gases: Capturing, Utilization and Reduction. Intech, 338 pp. [6] LI-COR Biosciences, 2011. Surface Monitoring for Geologic Carbon Sequestration Monitoring: Methods, Instrumentation, and Case Studies. LI-COR Biosciences, Pub. 980-11916, 15 pp. [7] Benson, S., 2006. Monitoring carbon dioxide sequestration in deep geological formations for inventory verification and carbon credits, SPE-102833, Presentation [8] Lewicki, J., G. Hilley, M. Fischer, L. Pan, C. Olden-burg, C. Dobeck, and L. Spangler, 2009.Eddy covariance observations of leakage during shallow subsurface CO2 releases. Journal of Geophys Res, 114: D12302 [9] Burba, G., 2013. Eddy Covariance Method for Scientific, Industrial, Agricultural and Regulatory Applications. LI-COR Biosciences, 328 pp. [10] LI-COR Biosciences, 2012. EddyPro 4.0: Help and User's Guide. Lincoln, NE, 208 pp.

The footprint of CO2 leakage in the water-column: Insights from numerical modeling based on a North Sea gas release experiment

Science.gov (United States)

Vielstädte, L.; Linke, P.; Schmidt, M.; Sommer, S.; Wallmann, K.; McGinnis, D. F.; Haeckel, M.

2013-12-01

Assessing the environmental impact of potential CO2 leakage from offshore carbon dioxide storage sites necessitates the investigation of the corresponding pH change in the water-column. Numerical models have been developed to simulate the buoyant rise and dissolution of CO2 bubbles in the water-column and the subsequent near-field dispersion of dissolved CO2 in seawater under ocean current and tidal forcing. In order to test and improve numerical models a gas release experiment has been conducted at 80 m water-depth within the Sleipner area (North Sea). CO2 and Kr (used as inert tracer gas) were released on top of a benthic lander at varying gas flows (impact of such leakage rates is limited to the near-field bottom waters, due to the rapid dissolution of CO2 bubbles in seawater (CO2 is being stripped within the first two to five meters of bubble rise). In particular, small bubbles, which will dissolve close to the seafloor, may cause a dangerous low-pH environment for the marine benthos. However, on the larger scale, the advective transport by e.g. tidal currents, dominates the CO2 dispersal in the North Sea and dilutes the CO2 peak quickly. The model results show that at the small scales (impact on the marine environment, thereby reducing pH substantially (by 0.4 units) within a diameter of less than 50 m around the release spot (depending on the duration of leakage and the current velocities). Strong currents and tidal cycles significantly reduce the spreading of low-pH water masses into the far-field by efficiently diluting the amount of CO2 in ambient seawater.

Imaging CO2 reservoirs using muons borehole detectors

Science.gov (United States)

Bonneville, A.; Bonal, N.; Lintereur, A.; Mellors, R. J.; Paulsson, B. N. P.; Rowe, C. A.; Varner, G. S.; Kouzes, R.; Flygare, J.; Mostafanezhad, I.; Yamaoka, J. A. K.; Guardincerri, E.; Chapline, G.

2016-12-01

Monitoring of the post-injection fate of CO2 in subsurface reservoirs is of utmost importance. Generally, monitoring options are active methods, such as 4D seismic reflection or pressure measurements in monitoring wells. We present a method of 4D density tomography of subsurface CO2 reservoirs using cosmic-ray muon detectors deployed in a borehole. Although muon flux rapidly decreases with depth, preliminary analyses indicate that the muon technique is sufficiently sensitive to effectively map density variations caused by fluid displacement at depths consistent with proposed CO2reservoirs. The intensity of the muon flux is, to first order, inversely proportional to the density times the path length, with resolution increasing with measurement time. The primary technical challenge preventing deployment of this technology in subsurface locations is the lack of miniaturized muon-tracking detectors both capable of fitting in standard boreholes and that will be able to resist the harsh underground conditions (temperature, pressure, corrosion) for long periods of time. Such a detector with these capabilities has been developed through a collaboration supported by the U.S. Department of Energy. A prototype has been tested in underground laboratories during 2016. In particular, we will present results from a series of tests performed in a tunnel comparing efficiencies, and angular and position resolution to measurements collected at the same locations by large instruments developed by Los Alamos and Sandia National Laboratories. We will also present the results of simulations of muon detection for various CO2 reservoir situations and muon detector configurations. Finally, to improve imaging of 3D subsurface structures, a combination of seismic data, gravity data, and muons can be used. Because seismic waves, gravity anomalies, and muons are all sensitive to density, the combination of two or three of these measurements promises to be a powerful way to improve spatial

Conversion of a moderately rewetted fen to a shallow lake - implications for net CO2 exchange

Science.gov (United States)

Koebsch, Franziska; Glatzel, Stephan; Hofmann, Joachim; Forbrich, Inke; Jurasinski, Gerald

2013-04-01

Extensive rewetting projects to re-establish the natural carbon (C) sequestration function of degraded peatlands are currently taking place in Europe and North-America. Year-round flooding provides a robust measure to prevent periods of drought that are associated with ongoing peat mineralization and to initiate the accumulation of new organic matter. Here, we present measurements of net carbon dioxide (CO2) exchange during the gradual conversion of a moderately rewetted fen to a shallow lake. When we started our measurements in 2009, mean growing season water level (MWGL) was 0 cm. In 2010 the site was flooded throughout the year with MWGL of 36 cm. Extraordinary strong rainfalls in July 2011 resulted in a further increase of MWGL to 56 cm. Measurements of net ecosystem exchange (NEE) were conducted during growing seasons (May-October) using the Eddy Covariance method. Information about vegetation vitality was deduced from the enhanced vegetation index (EVI) based on MODIS data. Ecosystem respiration (Reco) and gross ecosystem production (GEP) were high during vegetation period 2009 (1273.4 and -1572.1 g CO2-C m-2), but decreased by 61 and 46% respectively when the fen was flooded throughout 2010. Under water-logged conditions, heterotrophic respiration declines and gas exchange is limited. Moreover, flooding is a severe stress factor for plants and decreases autotrophic respiration and photosynthesis. However, in comparison to 2010, rates of Reco and GEP doubled during the beginning of growing season 2011, indicating plastic response strategies of wetland plants to flooding. Presumably, plants were not able to cope with the further increase of water levels to up to 120 cm in June/July 2011, resulting in another drop of GEP and Reco. The effects of plant vitality on GEP were confirmed by the remote sensed vegetation index. Throughout all three growing seasons, the fen was a distinct net CO2 sink (2009: -333.3±12.3, 2010: -294.1±8.4, -352.4±5.1 g CO2-C m-2

Liberation of microbial substrates from macromolecular organic matter by non-supercritical CO2

Science.gov (United States)

Sauer, P.; Glombitza, C.; Kallmeyer, J.

2012-12-01

The worldwide search for suitable underground storage formations for CO2 also considers coal-bearing strata. CO2 is already injected into coal seams for enhanced recovery of coal bed methane. However, the geochemical and microbiological effects of increased CO2 concentrations on organic matter rich formations are rarely investigated. The injected CO2 will dissolve in the pore water, causing a decrease in pH and resulting in acidic formation waters. Low molecular weight organic acids (LMWOAs) are chemically bound to the macromolecular matrix of sedimentary organic matter and may be liberated by hydrolysis, which is enhanced under acidic conditions. Recent investigations outlined the importance of LMWOAs as a feedstock for subsurface microbial life [1]. Therefore, injection of CO2 into coal formations may result in enhanced nutrient supply for subsurface microbes. To investigate the effects of highly CO2-saturated waters on the release of LMWOAs from coal, we developed an inexpensive high-pressure-high-temperature system that allows manipulating the concentration of dissolved gases up to 60 MPa and 120°C, respectively. The sample is placed in a flexible, gas-tight and inert PVDF sleeve, separating it from the pressure fluid and allowing for subsampling without loss of pressure. Lignite samples from the DEBITS-1 well, Waikato Basin, NZ and the Welzow-Süd open-cast mine, Niederlausitz, Germany, were extracted at 90° C and 5 MPa, with either pure water, CO2-saturated water, CO2/NO2 or CO2/SO2-saturated water. Subsamples were taken at different time points during the 72 hrs. long extraction. Extraction of LMWOAs from coal samples with our pressurised system resulted in yields that were up to four times higher than those reported for Soxhlet extraction [2]. These higher yields may be explained by the fact that during Soxhlet extraction the sample only gets into contact with freshly distilled water, whereas in our system the extraction fluid is circulated, resulting in

Shallow groundwater and soil chemistry response to 3 years of subsurface drip irrigation using coalbed-methane-produced water

Energy Technology Data Exchange (ETDEWEB)

Bern, C. R.; Boehlke, A. R.; Engle, M. A.; Geboy, N. J.; Schroeder, K. T.; Zupancic, J. W.

2013-10-04

Disposal of produced waters, pumped to the surface as part of coalbed methane (CBM) development, is a significant environmental issue in the Wyoming portion of the Powder River Basin, USA. High sodium adsorption ratios (SAR) of the waters could degrade agricultural land, especially if directly applied to the soil surface. One method of disposing of CBM water, while deriving beneficial use, is subsurface drip irrigation (SDI), where acidified CBM waters are applied to alfalfa fields year-round via tubing buried 0.92 m deep. Effects of the method were studied on an alluvial terrace with a relatively shallow depth to water table (~3 m). Excess irrigation water caused the water table to rise, even temporarily reaching the depth of drip tubing. The rise corresponded to increased salinity in some monitoring wells. Three factors appeared to drive increased groundwater salinity: (1) CBM solutes, concentrated by evapotranspiration; (2) gypsum dissolution, apparently enhanced by cation exchange; and (3) dissolution of native Na–Mg–SO{sub 4} salts more soluble than gypsum. Irrigation with high SAR (24) water has increased soil saturated paste SAR up to 15 near the drip tubing. Importantly though, little change in SAR has occurred at the surface.

Shallow groundwater and soil chemistry response to 3 years of subsurface drip irrigation using coalbed-methane-produced water

Science.gov (United States)

Bern, Carleton R.; Boehlke, Adam R.; Engle, Mark A.; Geboy, Nicholas J.; Schroeder, K.T.; Zupancic, J.W.

2013-01-01

Disposal of produced waters, pumped to the surface as part of coalbed methane (CBM) development, is a significant environmental issue in the Wyoming portion of the Powder River Basin, USA. High sodium adsorption ratios (SAR) of the waters could degrade agricultural land, especially if directly applied to the soil surface. One method of disposing of CBM water, while deriving beneficial use, is subsurface drip irrigation (SDI), where acidified CBM waters are applied to alfalfa fields year-round via tubing buried 0.92 m deep. Effects of the method were studied on an alluvial terrace with a relatively shallow depth to water table (∼3 m). Excess irrigation water caused the water table to rise, even temporarily reaching the depth of drip tubing. The rise corresponded to increased salinity in some monitoring wells. Three factors appeared to drive increased groundwater salinity: (1) CBM solutes, concentrated by evapotranspiration; (2) gypsum dissolution, apparently enhanced by cation exchange; and (3) dissolution of native Na–Mg–SO4 salts more soluble than gypsum. Irrigation with high SAR (∼24) water has increased soil saturated paste SAR up to 15 near the drip tubing. Importantly though, little change in SAR has occurred at the surface.

Functional response of a near-surface soil microbial community to a simulated underground CO2 storage leak.

Science.gov (United States)

Morales, Sergio E; Holben, William E

2013-01-01

Understanding the impacts of leaks from geologic carbon sequestration, also known as carbon capture and storage, is key to developing effective strategies for carbon dioxide (CO2) emissions management and mitigation of potential negative effects. Here, we provide the first report on the potential effects of leaks from carbon capture and storage sites on microbial functional groups in surface and near-surface soils. Using a simulated subsurface CO2 storage leak scenario, we demonstrate how CO2 flow upward through the soil column altered both the abundance (DNA) and activity (mRNA) of microbial functional groups mediating carbon and nitrogen transformations. These microbial responses were found to be seasonally dependent and correlated to shifts in atmospheric conditions. While both DNA and mRNA levels were affected by elevated CO2, they did not react equally, suggesting two separate mechanisms for soil microbial community response to high CO2 levels. The results did not always agree with previous studies on elevated atmospheric (rather than subsurface) CO2 using FACE (Free-Air CO2 Enrichment) systems, suggesting that microbial community response to CO2 seepage from the subsurface might differ from its response to atmospheric CO2 increases.

System analysis of shallow land burial. Volume 2: technical background. Technical report, 26 November 1979-23 January 1981

International Nuclear Information System (INIS)

Lester, D.; Buckley, D.; Donelson, S.; Dura, V.; Hecht, M.

1981-03-01

This is volume two of a three volume set detailing the activities and results of the System Analysis of Shallow Land Burial Project. Activities under four project tasks are described: Task 1 - Identify Potential Radionuclide Release Pathways, Task 2 - Systems Model for Shallow Land Burial of Low-Level Waste, Task 3 - Sensitivity and Optimization Study and Task 4 - Reference Facility Dose Assessment

Characterization of accumulated precipitates during subsurface iron removal

International Nuclear Information System (INIS)

Halem, Doris van; Vet, Weren de; Verberk, Jasper; Amy, Gary; Dijk, Hans van

2011-01-01

Research highlights: → Accumulated iron was not found to clog the well or aquifer after 12 years of subsurface iron removal. → 56-100% of accumulated iron hydroxides were found to be crystalline. → Subsurface iron removal favoured certain soil layers, either due to hydraulics or mineralogy. → Other groundwater constituents, such as manganese and arsenic were found to co-accumulate with iron. - Abstract: The principle of subsurface iron removal for drinking water supply is that aerated water is periodically injected into the aquifer through a tube well. On its way into the aquifer, the injected O 2 -rich water oxidizes adsorbed Fe 2+ , creating a subsurface oxidation zone. When groundwater abstraction is resumed, the soluble Fe 2+ is adsorbed and water with reduced Fe concentrations is abstracted for multiple volumes of the injection water. In this article, Fe accumulation deposits in the aquifer near subsurface treatment wells were identified and characterized to assess the sustainability of subsurface iron removal regarding clogging of the aquifer and the potential co-accumulation of other groundwater constituents, such as As. Chemical extraction of soil samples, with Acid-Oxalate and HNO 3 , showed that Fe had accumulated at specific depths near subsurface iron removal wells after 12 years of operation. Whether it was due to preferred flow paths or geochemical mineralogy conditions; subsurface iron removal clearly favoured certain soil layers. The total Fe content increased between 11.5 and 390.8 mmol/kg ds in the affected soil layers, and the accumulated Fe was found to be 56-100% crystalline. These results suggest that precipitated amorphous Fe hydroxides have transformed to Fe hydroxides of higher crystallinity. These crystalline, compact Fe hydroxides have not noticeably clogged the investigated well and/or aquifer between 1996 and 2008. The subsurface iron removal wells even need less frequent rehabilitation, as drawdown increases more slowly than in

Strategies towards an optimized use of the shallow geothermal potential

Science.gov (United States)

Schelenz, S.; Firmbach, L.; Kalbacher, T.; Goerke, U.; Kolditz, O.; Dietrich, P.; Vienken, T.

2013-12-01

Thermal use of the shallow subsurface for heat generation, cooling and thermal energy storage is increasingly gaining importance in reconsideration of future energy supplies, e.g. in the course of German energy transition, with application shifting from isolated to intensive use. The planning and dimensioning of (geo-)thermal applications is strongly influenced by the availability of exploration data. Hence, reliable site-specific dimensioning of systems for the thermal use of the shallow subsurface will contribute to an increase in resource efficiency, cost reduction during installation and operation, as well as reduction of environmental impacts and prevention of resource over-exploitation. Despite large cumulative investments that are being made for the utilization of the shallow thermal potential, thermal energy is in many cases exploited without prior on-site exploration and investigation of the local geothermal potential, due to the lack of adequate and cost-efficient exploration techniques. We will present new strategies for an optimized utilization of urban thermal potential, showcased at a currently developed residential neighborhood with high demand for shallow geothermal applications, based on a) enhanced site characterization and b) simulation of different site specific application scenarios. For enhanced site characterization, surface geophysics and vertical high resolution direct push-profiling were combined for reliable determination of aquifer structure and aquifer parameterization. Based on the site characterization, different site specific geothermal application scenarios, including different system types and system configurations, were simulated using OpenGeoSys to guarantee an environmental and economic sustainable thermal use of the shallow subsurface.

Adrenaline release evokes hyperpnoea and an increase in ventilatory CO2 sensitivity during hypoglycaemia: a role for the carotid body.

Science.gov (United States)

Thompson, Emma L; Ray, Clare J; Holmes, Andrew P; Pye, Richard L; Wyatt, Christopher N; Coney, Andrew M; Kumar, Prem

2016-08-01

Hypoglycaemia is counteracted by release of hormones and an increase in ventilation and CO2 sensitivity to restore blood glucose levels and prevent a fall in blood pH. The full counter-regulatory response and an appropriate increase in ventilation is dependent on carotid body stimulation. We show that the hypoglycaemia-induced increase in ventilation and CO2 sensitivity is abolished by preventing adrenaline release or blocking its receptors. Physiological levels of adrenaline mimicked the effect of hypoglycaemia on ventilation and CO2 sensitivity. These results suggest that adrenaline, rather than low glucose, is an adequate stimulus for the carotid body-mediated changes in ventilation and CO2 sensitivity during hypoglycaemia to prevent a serious acidosis in poorly controlled diabetes. Hypoglycaemia in vivo induces a counter-regulatory response that involves the release of hormones to restore blood glucose levels. Concomitantly, hypoglycaemia evokes a carotid body-mediated hyperpnoea that maintains arterial CO2 levels and prevents respiratory acidosis in the face of increased metabolism. It is unclear whether the carotid body is directly stimulated by low glucose or by a counter-regulatory hormone such as adrenaline. Minute ventilation was recorded during infusion of insulin-induced hypoglycaemia (8-17 mIU kg(-1)  min(-1) ) in Alfaxan-anaesthetised male Wistar rats. Hypoglycaemia significantly augmented minute ventilation (123 ± 4 to 143 ± 7 ml min(-1) ) and CO2 sensitivity (3.3 ± 0.3 to 4.4 ± 0.4 ml min(-1)  mmHg(-1) ). These effects were abolished by either β-adrenoreceptor blockade with propranolol or adrenalectomy. In this hypermetabolic, hypoglycaemic state, propranolol stimulated a rise in P aC O2, suggestive of a ventilation-metabolism mismatch. Infusion of adrenaline (1 μg kg(-1)  min(-1) ) increased minute ventilation (145 ± 4 to 173 ± 5 ml min(-1) ) without altering P aC O2 or pH and enhanced ventilatory CO2 sensitivity (3

Development of a CO2 -releasing coformulation based on starch, Saccharomyces cerevisiae and Beauveria bassiana attractive towards western corn rootworm larvae.

Science.gov (United States)

Vemmer, Marina; Schumann, Mario; Beitzen-Heineke, Wilhelm; French, Bryan W; Vidal, Stefan; Patel, Anant V

2016-11-01

CO 2 is known as an attractant for many soil-dwelling pests. To implement an attract-and-kill strategy for soil pest control, CO 2 -emitting formulations need to be developed. The aim of the present work was to develop a slow-release bead system in order to bridge the gap between application and hatching of western corn rootworm larvae. We compared different Ca-alginate beads containing Saccharomyces cerevisiae for their potential to release CO 2 over a period of several weeks. The addition of starch improved CO 2 release, resulting in significantly higher CO 2 concentrations in soil for at least 4 weeks. The missing amylase activity was compensated for either by microorganisms present in the soil or by coencapsulation of Beauveria bassiana. Formulations containing S. cerevisiae, starch and B. bassiana were attractive for western corn rootworm larvae within the first 4 h following exposure; however, when considering the whole testing period, the maize root systems remained more attractive for the larvae. Coencapsulation of S. cerevisiae, starch and B. bassiana is a promising approach for the development of attractive formulations for soil applications. For biological control strategies, the attractiveness needs to be increased by phagostimuli to extend contact between larvae and the entomopathogenic fungus growing out of these formulations. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Characterizing the potential for fault reactivation related to CO2 injection through subsurface structural mapping and stress field analysis, Wellington Field, Sumner County, KS

Science.gov (United States)

Schwab, D.; Bidgoli, T.; Taylor, M. H.

2015-12-01

South-central Kansas has experienced an unprecedented increase in seismic activity since 2013. The spatial and temporal relationship of the seismicity with brine disposal operations has renewed interest in the role of fluids in fault reactivation. This study focuses on determining the suitability of CO2 injection into a Cambro-Ordovician reservoir for long-term storage and a Mississippian reservoir for enhanced oil recovery in Wellington Field, Sumner County, Kansas. Our approach for determining the potential for induced seismicity has been to (1) map subsurface faults and estimate in-situ stresses, (2) perform slip and dilation tendency analysis to identify optimally-oriented faults relative to the estimated stress field, and (3) monitor surface deformation through cGPS data and InSAR imaging. Through the use of 3D seismic reflection data, 60 near vertical, NNE-striking faults have been identified. The faults range in length from 140-410 m and have vertical separations of 3-32m. A number of faults appear to be restricted to shallow intervals, while others clearly cut the top basement reflector. Drilling-induced tensile fractures (N=78) identified from image logs and inversion of earthquake focal mechanism solutions (N=54) are consistent with the maximum horizontal stress (SHmax) oriented ~E-W. Both strike-slip and normal-slip fault plane solutions for earthquakes near the study area suggest that SHmax and Sv may be similar in magnitude. Estimates of stress magnitudes using step rate tests (Shmin = 2666 psi), density logs (Sv = 5308 psi), and calculations from wells with drilling induced tensile fractures (SHmax = 4547-6655 psi) are determined at the gauge depth of 4869ft. Preliminary slip and dilation tendency analysis indicates that faults striking 0°-20° are stable, whereas faults striking 26°-44° may have a moderate risk for reactivation with increasing pore-fluid pressure.

Smouldering Subsurface Fires in the Earth System

Science.gov (United States)

Rein, Guillermo

2010-05-01

Smouldering fires, the slow, low-temperature, flameless form of combustion, are an important phenomena in the Earth system. These fires propagate slowly through organic layers of the forest ground and are responsible for 50% or more of the total biomass consumed during wildfires. Only after the 2002 study of the 1997 extreme haze event in South-East Asia, the scientific community recognised the environmental and economic threats posed by subsurface fires. This was caused by the spread of vast biomass fires in Indonesia, burning below the surface for months during the El Niño climate event. It has been calculated that these fires released between 0.81 and 2.57 Gton of carbon gases (13-40% of global emissions). Large smouldering fires are rare events at the local scale but occur regularly at a global scale. Once ignited, they are particularly difficult to extinguish despite extensive rains or fire-fighting attempts and can persist for long periods of time (months, years) spreading over very extensive areas of forest and deep into the soil. Indeed, these are the oldest continuously burning fires on Earth. Earth scientists are interested in smouldering fires because they destroy large amounts of biomass and cause greater damage to the soil ecosystem than flaming fires do. Moreover, these fires cannot be detected with current satellite remote sensing technologies causing inconsistencies between emission inventories and model predictions. Organic soils sustain smouldering fire (hummus, duff, peat and coal) which total carbon pool exceeds that of the world's forests or the atmosphere. This have important implications for climate change. Warmer temperatures at high latitudes are resulting in unprecedented permafrost thaw that is leaving large soil carbon pools exposed to fires. Because the CO2 flux from peat fires has been measured to be about 3000 times larger that the natural degradation flux, permafrost thaw is a risk for greater carbon release by fire and subsequently

Development of sustained and dual drug release co-extrusion formulations for individual dosing.

Science.gov (United States)

Laukamp, Eva Julia; Vynckier, An-Katrien; Voorspoels, Jody; Thommes, Markus; Breitkreutz, Joerg

2015-01-01

In personalized medicine and patient-centered medical treatment individual dosing of medicines is crucial. The Solid Dosage Pen (SDP) allows for an individual dosing of solid drug carriers by cutting them into tablet-like slices. The aim of the present study was the development of sustained release and dual release formulations with carbamazepine (CBZ) via hot-melt co-extrusion for the use in the SDP. The selection of appropriate coat- and core-formulations was performed by adapting the mechanical properties (like tensile strength and E-modulus) for example. By using different excipients (polyethyleneglycols, poloxamers, white wax, stearic acid, and carnauba wax) and drug loadings (30-50%) tailored dissolution kinetics was achieved showing cube root or zero order release mechanisms. Besides a biphasic drug release, the dose-dependent dissolution characteristics of sustained release formulations were minimized by a co-extruded wax-coated formulation. The dissolution profiles of the co-extrudates were confirmed during short term stability study (six months at 21.0 ± 0.2 °C, 45%r.h.). Due to a good layer adhesion of core and coat and adequate mechanical properties (maximum cutting force of 35.8 ± 2.0 N and 26.4 ± 2.8 N and E-modulus of 118.1 ± 8.4 and 33.9 ± 4.5 MPa for the dual drug release and the wax-coated co-extrudates, respectively) cutting off doses via the SDP was precise. While differences of the process parameters (like the barrel temperature) between the core- and the coat-layer resulted in unsatisfying content uniformities for the wax-coated co-extrudates, the content uniformity of the dual drug release co-extrudates was found to be in compliance with pharmacopoeial specification. Copyright © 2015 Elsevier B.V. All rights reserved.

Response of atmospheric CO2 to changes in land use

International Nuclear Information System (INIS)

King, A.W.; Emanuel, W.R.; Post, W.M.

1991-01-01

This chapter examines how different histories of CO 2 release from past changes in land use influence the simulation of past and future changes in atmospheric CO 2 . The authors first simulate past change in atmospheric CO 2 using reconstructed histories of land-use CO 2 release from a historical-ecological model of land-use change and CO 2 release. They examine the impact of each history on the coincidence between simulated and observed atmospheric CO 2 . They then compare these CO 2 release histories, and their contribution to coincidence or noncoincidence of simulation and observation, with histories reconstructed by deconvolution of the atmospheric CO 2 record. They conclude by exploring the implications of these deconvolved reconstructions for the simulation of future changes in atmospheric CO 2

Thermodynamic and Kinetic Response of Microbial Reactions to High CO2.

Science.gov (United States)

Jin, Qusheng; Kirk, Matthew F

2016-01-01

Geological carbon sequestration captures CO 2 from industrial sources and stores the CO 2 in subsurface reservoirs, a viable strategy for mitigating global climate change. In assessing the environmental impact of the strategy, a key question is how microbial reactions respond to the elevated CO 2 concentration. This study uses biogeochemical modeling to explore the influence of CO 2 on the thermodynamics and kinetics of common microbial reactions in subsurface environments, including syntrophic oxidation, iron reduction, sulfate reduction, and methanogenesis. The results show that increasing CO 2 levels decreases groundwater pH and modulates chemical speciation of weak acids in groundwater, which in turn affect microbial reactions in different ways and to different extents. Specifically, a thermodynamic analysis shows that increasing CO 2 partial pressure lowers the energy available from syntrophic oxidation and acetoclastic methanogenesis, but raises the available energy of microbial iron reduction, hydrogenotrophic sulfate reduction and methanogenesis. Kinetic modeling suggests that high CO 2 has the potential of inhibiting microbial sulfate reduction while promoting iron reduction. These results are consistent with the observations of previous laboratory and field studies, and highlight the complexity in microbiological responses to elevated CO 2 abundance, and the potential power of biogeochemical modeling in evaluating and quantifying these responses.

Thermodynamic and kinetic response of microbial reactions to high CO2

Directory of Open Access Journals (Sweden)

Qusheng Jin

2016-11-01

Full Text Available Geological carbon sequestration captures CO2 from industrial sources and stores the CO2 in subsurface reservoirs, a viable strategy for mitigating global climate change. In assessing the environmental impact of the strategy, a key question is how microbial reactions respond to the elevated CO2 concentration. This study uses biogeochemical modeling to explore the influence of CO2 on the thermodynamics and kinetics of common microbial reactions in subsurface environments, including syntrophic oxidation, iron reduction, sulfate reduction, and methanogenesis. The results show that increasing CO2 levels decreases groundwater pH and modulates chemical speciation of weak acids in groundwater, which in turn affect microbial reactions in different ways and to different extents. Specifically, a thermodynamic analysis shows that increasing CO2 partial pressure lowers the energy available from syntrophic oxidation and acetoclastic methanogenesis, but raises the available energy of microbial iron reduction, hydrogenotrophic sulfate reduction and methanogenesis. Kinetic modeling suggests that high CO2 has the potential of inhibiting microbial sulfate reduction while promoting iron reduction. These results are consistent with the observations of previous laboratory and field studies, and highlight the complexity in microbiological responses to elevated CO2 abundance, and the potential power of biogeochemical modeling in evaluating and quantifying these responses.

Biogeochemical Controls on the Release and Accumulation of Mn and As in Shallow Aquifers, West Bengal, India

Directory of Open Access Journals (Sweden)

Michael A. Vega

2017-06-01

Full Text Available HIGHLIGHTSManganese and arsenic concentrations are elevated in Murshidabad groundwater.Manganese release appears to be independent of dissolved organic matter quality.Mineral precipitation and dissolution reactions impact fate of manganese.Arsenic concentrations are related to dissolved organic matter quantity and quality.The prevalence of manganese (Mn in Southeast Asian drinking water has recently become a topic of discussion, particularly when concurrent with elevated arsenic (As. Although Mn groundwater geochemistry has been studied, the link between dissolved organic matter (DOM quality and Mn release is less understood. This work evaluates characteristics of DOM, redox chemistry, and the distribution of Mn within Murshidabad, West Bengal, India. Shallow aquifer samples were analyzed for cations, anions, dissolved organic carbon, and DOM properties using 3-dimensional fluorescence excitation emission matrices followed by parallel factor modeling analyses. Two biogeochemical regimes are apparent, separated geographically by the river Bhagirathi. East of the river, where Eh and nitrate (NO3− values are low, humic-like DOM coexists with high dissolved Mn, As, and Fe. West of the river, lower dissolved As and Fe concentrations are coupled with more protein-like DOM and higher NO3− and Eh values. Dissolved Mn concentrations are elevated in both regions. Based on the distribution of available electron acceptors, it is hypothesized that groundwater east of the Bhagirathi, which is more reducing and enriched in dissolved Fe and Mn but depleted in NO3−, is chemically dominated by Mn(IV/Fe(III reduction processes. West of the river where NO3− is abundant yet dissolved Fe is absent, NO3− and Mn(IV likely buffer redox conditions such that Eh values are not sufficiently reducing to release Fe into the dissolved phase. The co-occurrence of humic-like DOM with dissolved As, Fe, and Mn in the more reducing aquifers may reflect complex formation

Influence of the tension-saturated zone on contaminant migration in shallow water-table regimes

International Nuclear Information System (INIS)

Gillham, R.W.

1982-01-01

Groundwater discharge represents a major pathway for the return to the biosphere of contaminants that are released to the subsurface environment. An understanding of the transport processes in groundwater discharge zones is therefore an important consideration in pathway analyses associated with the environmental assessment of proposed waste-management facilities. Shallow water tables are a common characteristic of groundwater discharge zones, particularly in humid climatic regions. In this paper, the results of field tests, laboratory tests and numerical simulations are used to show that under shallow water-table conditions, the zone of tension saturation can result in a rapid and highly disproportionate water-table response to precipitation. It is further shown that this response can result in complex migration patterns that would not be predicted by the classical approaches to solute transport modelling and that the response could result in large and highly transient inputs to surface water

Advancing Knowledge on Fugitive Natural Gas from Energy Resource Development at a Controlled Release Field Observatory

Science.gov (United States)

Cahill, A. G.; Chao, J.; Forde, O.; Prystupa, E.; Mayer, K. U.; Black, T. A.; Tannant, D. D.; Crowe, S.; Hallam, S.; Mayer, B.; Lauer, R. M.; van Geloven, C.; Welch, L. A.; Salas, C.; Levson, V.; Risk, D. A.; Beckie, R. D.

2017-12-01

Fugitive gas, comprised primarily of methane, can be unintentionally released from upstream oil and gas development either at surface from leaky infrastructure or in the subsurface through failure of energy well bore integrity. For the latter, defective cement seals around energy well casings may permit buoyant flow of natural gas from the deeper subsurface towards shallow aquifers, the ground surface and potentially into the atmosphere. Concerns associated with fugitive gas release at surface and in the subsurface include contributions to greenhouse gas emissions, subsurface migration leading to accumulation in nearby infrastructure and impacts to groundwater quality. Current knowledge of the extent of fugitive gas leakage including how to best detect and monitor over time, and particularly its migration and fate in the subsurface, is incomplete. We have established an experimental field observatory for evaluating fugitive gas leakage in an area of historic and ongoing hydrocarbon resource development within the Montney Resource Play of the Western Canadian Sedimentary Basin, British Columbia, Canada. Natural gas will be intentionally released at surface and up to 25 m below surface at various rates and durations. Resulting migration patterns and impacts will be evaluated through examination of the geology, hydrogeology, hydro-geochemistry, isotope geochemistry, hydro-geophysics, vadose zone and soil gas processes, microbiology, and atmospheric conditions. The use of unmanned aerial vehicles and remote sensors for monitoring and detection of methane will also be assessed for suitability as environmental monitoring tools. Here we outline the experimental design and describe initial research conducted to develop a detailed site conceptual model of the field observatory. Subsequently, results attained from pilot surface and sub-surface controlled natural gas releases conducted in late summer 2017 will be presented as well as results of numerical modelling conducted

Rolling stones. Fast weathering of olivine in shallow seas for cost-effective CO2 capture and mitigation of global warming and ocean acidification

Energy Technology Data Exchange (ETDEWEB)

Schuiling, R.D.; De Boer, P.L. [Department of Earth Sciences, Utrecht University, P.O. Box 80.021, 3508TA Utrecht (Netherlands)

2011-07-01

Human CO2 emissions may drive the Earth into a next greenhouse state. They can be mitigated by accelerating weathering of natural rock under the uptake of CO2. We disprove the paradigm that olivine weathering in nature would be a slow process, and show that it is not needed to mill olivine to very fine, 10 {mu}m-size grains in order to arrive at a complete dissolution within 1-2 year. In high-energy shallow marine environments olivine grains and reaction products on the grain surfaces, that otherwise would greatly retard the reaction, are abraded so that the chemical reaction is much accelerated. When kept in motion even large olivine grains rubbing and bumping against each other quickly produce fine clay- and silt-sized olivine particles that show a fast chemical reaction. Spreading of olivine in the world's 2% most energetic shelf seas can compensate a year's global CO2 emissions and counteract ocean acidification against a price well below that of carbon credits.

In situ detection of anaerobic alkane metabolites in subsurface environments

Directory of Open Access Journals (Sweden)

Lisa eGieg

2013-06-01

Full Text Available Alkanes comprise a substantial fraction of crude oil and refined fuels. As such, they are prevalent within deep subsurface fossil fuel deposits and in shallow subsurface environments such as aquifers that are contaminated with hydrocarbons. These environments are typically anaerobic, and host diverse microbial communities that can potentially use alkanes as substrates. Anaerobic alkane biodegradation has been reported to occur under nitrate-reducing, sulfate-reducing, and methanogenic conditions. Elucidating the pathways of anaerobic alkane metabolism has been of interest in order to understand how microbes can be used to remediate contaminated sites. Alkane activation primarily occurs by addition to fumarate, yielding alkylsuccinates, unique anaerobic metabolites that can be used to indicate in situ anaerobic alkane metabolism. These metabolites have been detected in hydrocarbon-contaminated shallow aquifers, offering strong evidence for intrinsic anaerobic bioremediation. Recently, studies have also revealed that alkylsuccinates are present in oil and coal seam production waters, indicating that anaerobic microbial communities can utilize alkanes in these deeper subsurface environments. In many crude oil reservoirs, the in situ anaerobic metabolism of hydrocarbons such as alkanes may be contibuting to modern-day detrimental effects such as oilfield souring, or may lead to more benefical technologies such as enhanced energy recovery from mature oilfields. In this review, we briefly describe the key metabolic pathways for anaerobic alkane (including n-alkanes, isoalkanes, and cyclic alkanes metabolism and highlight several field reports wherein alkylsuccinates have provided evidence for anaerobic in situ alkane metabolism in shallow and deep subsurface environments.

Role of rainwater induced subsurface flow in water-level dynamics and thermoerosion of shallow thermokarst ponds on the Northeastern Qinghai-Tibet Plateau

Science.gov (United States)

Pan, X.; Yu, Q.; You, Y.

2014-12-01

Understanding hydrological and thermal regimes of thermokarst lakes is of great importance for predicting their responses to climate change. However, mechanism of water-level dynamics and associated thermal effects on thermoerosion of thermokarst lakes are still not well understood on the Qinghai-Tibet Plateau (QTP). In this study, we investigate two typical shallow thermokarst ponds (namely small lakes) in a warm permafrost region with thick active layer on the northeastern QTP through quantifying water budget. Results demonstrate that, rainfall induced subsurface lateral flow dominates pond water-level regime. Annual variation of pond water-level relies on areal water budget of surrounding active layer, particularly the high variable of precipitation. Besides, it is worth noting the extraordinary warming during the late ice-cover period, because marked air gap between upper ice-cover and underlying water, led by the upward thawing of thick ice-cover, might result in greenhouse-like condition due to the unique weather that strong solar radiation and little snowpack. This hydrological mechanism also exerts evident impacts on thermal regime and thermoerosion of the shallow thermokarst ponds, and they are closely related to retreat of thermokarst pondshore and underlying permafrost degradation. These findings imply a localized model addressing the unique hydrological and thermal regimes of thermokarst lakes would be essential to study the evolution of these shallow rainwater dominated thermokarst ponds on the QTP.

Low-level waste shallow burial assessment code

International Nuclear Information System (INIS)

Fields, D.E.; Little, C.A.; Emerson, C.J.

1981-01-01

PRESTO (Prediction of Radiation Exposures from Shallow Trench Operationns) is a computer code developed under United States Environmental Protection Agency funding to evaluate possible health effects from radionuclide releases from shallow, radioctive-waste disposal trenches and from areas contaminated with operational spillage. The model is intended to predict radionuclide transport and the ensuing exposure and health impact to a stable, local population for a 1000-year period following closure of the burial grounds. Several classes of submodels are used in PRESTO to represent scheduled events, unit system responses, and risk evaluation processes. The code is modular to permit future expansion and refinement. Near-surface transport mechanisms considered in the PRESTO code are cap failure, cap erosion, farming or reclamation practices, human intrusion, chemical exchange within an active surface soil layer, contamination from trench overflow, and dilution by surface streams. Subsurface processes include infiltration and drainage into the trench, the ensuing solubilization of radionuclides, and chemical exchange between trench water and buried solids. Mechanisms leading to contaminated outflow include trench overflow and downwad vertical percolation. If the latter outflow reaches an aquifer, radiological exposure from irrigation or domestic consumption is considered. Airborne exposure terms are evaluated using the Gaussian plume atmospheric transport formulation as implemented by Fields and Miller

Geochemical Influence on Microbial Communities at CO2-Leakage Analog Sites.

Science.gov (United States)

Ham, Baknoon; Choi, Byoung-Young; Chae, Gi-Tak; Kirk, Matthew F; Kwon, Man Jae

2017-01-01

Microorganisms influence the chemical and physical properties of subsurface environments and thus represent an important control on the fate and environmental impact of CO 2 that leaks into aquifers from deep storage reservoirs. How leakage will influence microbial populations over long time scales is largely unknown. This study uses natural analog sites to investigate the long-term impact of CO 2 leakage from underground storage sites on subsurface biogeochemistry. We considered two sites with elevated CO 2 levels (sample groups I and II) and one control site with low CO 2 content (group III). Samples from sites with elevated CO 2 had pH ranging from 6.2 to 4.5 and samples from the low-CO 2 control group had pH ranging from 7.3 to 6.2. Solute concentrations were relatively low for samples from the control group and group I but high for samples from group II, reflecting varying degrees of water-rock interaction. Microbial communities were analyzed through clone library and MiSeq sequencing. Each 16S rRNA analysis identified various bacteria, methane-producing archaea, and ammonia-oxidizing archaea. Both bacterial and archaeal diversities were low in groundwater with high CO 2 content and community compositions between the groups were also clearly different. In group II samples, sequences classified in groups capable of methanogenesis, metal reduction, and nitrate reduction had higher relative abundance in samples with relative high methane, iron, and manganese concentrations and low nitrate levels. Sequences close to Comamonadaceae were abundant in group I, while the taxa related to methanogens, Nitrospirae , and Anaerolineaceae were predominant in group II. Our findings provide insight into subsurface biogeochemical reactions that influence the carbon budget of the system including carbon fixation, carbon trapping, and CO 2 conversion to methane. The results also suggest that monitoring groundwater microbial community can be a potential tool for tracking CO 2

Geochemical Influence on Microbial Communities at CO2-Leakage Analog Sites

Directory of Open Access Journals (Sweden)

Baknoon Ham

2017-11-01

Full Text Available Microorganisms influence the chemical and physical properties of subsurface environments and thus represent an important control on the fate and environmental impact of CO2 that leaks into aquifers from deep storage reservoirs. How leakage will influence microbial populations over long time scales is largely unknown. This study uses natural analog sites to investigate the long-term impact of CO2 leakage from underground storage sites on subsurface biogeochemistry. We considered two sites with elevated CO2 levels (sample groups I and II and one control site with low CO2 content (group III. Samples from sites with elevated CO2 had pH ranging from 6.2 to 4.5 and samples from the low-CO2 control group had pH ranging from 7.3 to 6.2. Solute concentrations were relatively low for samples from the control group and group I but high for samples from group II, reflecting varying degrees of water-rock interaction. Microbial communities were analyzed through clone library and MiSeq sequencing. Each 16S rRNA analysis identified various bacteria, methane-producing archaea, and ammonia-oxidizing archaea. Both bacterial and archaeal diversities were low in groundwater with high CO2 content and community compositions between the groups were also clearly different. In group II samples, sequences classified in groups capable of methanogenesis, metal reduction, and nitrate reduction had higher relative abundance in samples with relative high methane, iron, and manganese concentrations and low nitrate levels. Sequences close to Comamonadaceae were abundant in group I, while the taxa related to methanogens, Nitrospirae, and Anaerolineaceae were predominant in group II. Our findings provide insight into subsurface biogeochemical reactions that influence the carbon budget of the system including carbon fixation, carbon trapping, and CO2 conversion to methane. The results also suggest that monitoring groundwater microbial community can be a potential tool for tracking

Rechargeable Al-CO2 Batteries for Reversible Utilization of CO2.

Science.gov (United States)

Ma, Wenqing; Liu, Xizheng; Li, Chao; Yin, Huiming; Xi, Wei; Liu, Ruirui; He, Guang; Zhao, Xian; Luo, Jun; Ding, Yi

2018-05-21

The excessive emission of CO 2 and the energy crisis are two major issues facing humanity. Thus, the electrochemical reduction of CO 2 and its utilization in metal-CO 2 batteries have attracted wide attention because the batteries can simultaneously accelerate CO 2 fixation/utilization and energy storage/release. Here, rechargeable Al-CO 2 batteries are proposed and realized, which use chemically stable Al as the anode. The batteries display small discharge/charge voltage gaps down to 0.091 V and high energy efficiencies up to 87.7%, indicating an efficient battery performance. Their chemical reaction mechanism to produce the performance is revealed to be 4Al + 9CO 2 ↔ 2Al 2 (CO 3 ) 3 + 3C, by which CO 2 is reversibly utilized. These batteries are envisaged to effectively and safely serve as a potential CO 2 fixation/utilization strategy with stable Al. © 2018 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Your View or Mine: Spatially Quantifying CO2 Storage Risk from Various Stakeholder Perspectives

Science.gov (United States)

Bielicki, J. M.; Pollak, M.; Wilson, E.; Elliot, T. R.; Guo, B.; Nogues, J. P.; Peters, C. A.

2011-12-01

CO2 capture and storage involves injecting captured CO2 into geologic formations, such as deep saline aquifers. This injected CO2 is to be "stored" within the rock matrix for hundreds to thousands of years, but injected CO2, or the brine it displaces, may leak from the target reservoir. Such leakage could interfere with other subsurface activities-water production, energy production, energy storage, and waste disposal-or migrate to the surface. Each of these interferences will incur multiple costs to a variety of stakeholders. Even if injected or displaced fluids do not interfere with other subsurface activities or make their way to the surface, costs will be incurred to find and fix the leak. Consequently, the suitability of a site for CO2 storage must therefore include an assessment of the risk of leakage and interference with various other activities within a three-dimensional proximity of where CO2 is being injected. We present a spatial analysis of leakage and interference risk associated with injecting CO2 into a portion of the Mount Simon sandstone in the Michigan Basin. Risk is the probability of an outcome multiplied by the impact of that outcome (Ro=po*Io). An outcome is the result of the leakage (e.g., interference with oil production), and the impact is the cost associated with the outcome. Each outcome has costs that will vary by stakeholder. Our analysis presents CO2 storage risk for multiple outcomes in a spatially explicit manner that varies by stakeholder. We use the ELSA semi-analytical model for estimating CO2 and brine leakage from aquifers to determine plume and pressure front radii, and CO2 and brine leakage probabilities for the Mount Simon sandstone and multiple units above it. Results of ELSA simulations are incorporated into RISCS: the Risk Interference Subsurface CO2 Storage model. RISCS uses three-dimensional data on subsurface geology and the locations of wells and boreholes to spatially estimate risks associated with CO2 leakage from

Effects of tillage practice and atmospheric CO2 level on soil CO2 efflux

Science.gov (United States)

Elevated atmospheric carbon dioxide (CO2) affects both the quantity and quality of plant tissues, which impacts the cycling and storage of carbon (C) within plant/soil systems and thus the rate of CO2 release back to the atmosphere. Research to accurately quantify the effects of elevated CO2 and as...

Atmospheric 14C changes resulting from fossil fuel CO2 release and cosmic ray flux variability

International Nuclear Information System (INIS)

Stuiver, M.; Quay, P.D.

1981-01-01

A high-precision tree-ring record of the atmospheric 14 C levels between 1820 and 1954 is presented. Good agreement is obtained between measured and model calculated 19th and 20th century atmospheric δ 14 C levels when both fossil fuel CO 2 release and predicted natural variations in 14 C production are taken into account. The best fit is obtained by using a box-diffusion model with an oceanic eddy diffusion coefficient of 3 cm 2 /s, a CO 2 atmosphere-ocean gas exchange rate of 21 moles msup(-2) yrsup(-1) and biospheric residence time of 60 years. For trees in the state of Washington the measured 1949-1951 atmospheric δ 14 C level was 20.0 +- 1.2per mille below the 1855-1864 level. Model calculations indicate that in 1950 industrial CO 2 emissions are responsible for at least 85% of the δ 14 C decline, whereas natural variability accounts for the remaining 15%. (orig.)

The impact of sedimentary alkalinity release on the water column CO

NARCIS (Netherlands)

Brenner, H.; Braeckman, U.; Le Guitton, M.; Meysman, F.J.R.

2016-01-01

It has been previously proposed that alkalinity release from sediments can play an important role in the carbonate dynamics on continental shelves, lowering the pCO₂ of seawater and hence increasing the CO₂ uptake from the atmosphere. To test this hypothesis, sedimentary

Inferring Shallow Subsurface Density Structure from Surface and Underground Gravity Measurements: Calibrating Models for Relatively Undeformed Volcanic Strata at the Jemez Volcanic Field, New Mexico, USA

Science.gov (United States)

Roy, Mousumi; Lewis, Megan; Johnson, Alex; George, Nicolas; Rowe, Charlotte; Guardincerri, Elena

2018-03-01

Imaging shallow subsurface density structure is an important goal in a variety of applications, from hydrogeology to seismic and volcanic hazard assessment. We assess the effectiveness of surface and subsurface gravity measurements in estimating the density structure of a well-characterized rock volume: the mesa (a small, flat-topped plateau) upon which the town of Los Alamos, New Mexico, USA is located. Our gravity measurements were made on the mesa surface above a horizontal tunnel and underground, within the tunnel. We demonstrate that, in the absence of other geophysical data such as seismic data or muon attenuation, subsurface (tunnel) gravity measurements are critical to accurately recovering geologic structure. Without the tunnel data, our resolution is limited to roughly the surface gravity station spacing, but by including the tunnel data we can resolve structure to a depth of 10 times the surface gravity station spacing. Densities were obtained using both forward modeling and a Bayesian inverse modeling approach, incorporating relevant constraints from geologic observations. We find that Bayesian inversion, with geologically relevant prior, is a superior approach to the forward models in terms of both robustness and efficiency and correctly predicts the orientation and elevation of important geologic features.

Measuring permanence of CO2 storage in saline formations: The Frio experiment

Science.gov (United States)

Hovorka, Susan D.; Benson, Sally M.; Doughty, Christine; Freifeild, Barry M.; Sakurai, Shinichi; Daley, Thomas M.; Kharaka, Yousif K.; Holtz, Mark H.; Trautz, Robert C.; Nance, H. Seay; Myer, Larry R.; Knauss, Kevin G.

2006-01-01

If CO2 released from fossil fuel during energy production is returned to the subsurface, will it be retained for periods of time significant enough to benefit the atmosphere? Can trapping be assured in saline formations where there is no history of hydrocarbon accumulation? The Frio experiment in Texas was undertaken to provide answers to these questions.One thousand six hundred metric tons of CO2 were injected into the Frio Formation, which underlies large areas of the United States Gulf Coast. Reservoir characterization and numerical modeling were used to design the experiment, as well as to interpret the results through history matching. Closely spaced measurements in space and time were collected to observe the evolution of immiscible and dissolved CO2 during and after injection. The high-permeability, steeply dipping sandstone allowed updip flow of supercritical CO2 as a result of the density contrast with formation brine and absence of a local structural trap.The front of the CO2 plume moved more quickly than had been modeled. By the end of the 10-day injection, however, the plume geometry in the plane of the observation and injection wells had thickened to a distribution similar to the modeled distribution. As expected, CO2 dissolved rapidly into brine, causing pH to fall and calcite and metals to be dissolved.Postinjection measurements, including time-lapse vertical seismic profiling transects along selected azimuths, cross-well seismic topography, and saturation logs, show that CO2 migration under gravity slowed greatly 2 months after injection, matching model predictions that significant CO2 is trapped as relative permeability decreases.

Multiple isotopes (O, C, Li, Sr) as tracers of CO2 and brine leakage from CO2-enhanced oil recovery activities in Permian Basin, Texas, USA

Science.gov (United States)

Phan, T. T.; Sharma, S.; Gardiner, J. B.; Thomas, R. B.; Stuckman, M.; Spaulding, R.; Lopano, C. L.; Hakala, A.

2017-12-01

Potential CO2 and brine migration or leakage into shallow groundwater is a critical issue associated with CO2 injection at both enhanced oil recovery (EOR) and carbon sequestration sites. The effectiveness of multiple isotope systems (δ18OH2O, δ13C, δ7Li, 87Sr/86Sr) in monitoring CO2 and brine leakage at a CO2-EOR site located within the Permian basin (Seminole, Texas, USA) was studied. Water samples collected from an oil producing formation (San Andres), a deep groundwater formation (Santa Rosa), and a shallow groundwater aquifer (Ogallala) over a four-year period were analyzed for elemental and isotopic compositions. The absence of any change in δ18OH2O or δ13CDIC values of water in the overlying Ogallala aquifer after CO2 injection indicates that injected CO2 did not leak into this aquifer. The range of Ogallala water δ7Li (13-17‰) overlaps the San Andres water δ7Li (13-15‰) whereas 87Sr/86Sr of Ogallala (0.70792±0.00005) significantly differs from San Andres water (0.70865±0.00003). This observation demonstrates that Sr isotopes are much more sensitive than Li isotopes in tracking brine leakage into shallow groundwater at the studied site. In contrast, deep groundwater δ7Li (21-25‰) is isotopically distinct from San Andres produced water; thus, monitoring this intermitted formation water can provide an early indication of CO2 injection-induced brine migration from the underlying oil producing formation. During water alternating with gas (WAG) operations, a significant shift towards more positive δ13CDIC values was observed in the produced water from several of the San Andres formation wells. The carbon isotope trend suggests that the 13C enriched injected CO2 and formation carbonates became the primary sources of dissolved inorganic carbon in the area surrounding the injection wells. Moreover, one-way ANOVA statistical analysis shows that the differences in δ7Li (F(1,16) = 2.09, p = 0.17) and 87Sr/86Sr (F(1,18) = 4.47, p = 0.05) values of

Integrated study on the topographic and shallow subsurface expression of the Grote Brogel Fault at the boundary of the Roer Valley Graben, Belgium

Science.gov (United States)

Deckers, Jef; Van Noten, Koen; Schiltz, Marco; Lecocq, Thomas; Vanneste, Kris

2018-01-01

The Grote Brogel Fault (GBF) is a major WNW-ESE striking normal fault in Belgium that diverges westward from the NW-SE striking western border fault system of the Roer Valley Graben. The GBF delimits the topographically higher Campine Block from the subsiding Roer Valley Graben, and is expressed in the Digital Terrain Model (DTM) by relief gradients or scarps. By integrating DTM, Electrical Resistivity Tomography (ERT), Cone Penetration Test (CPT) and borehole data, we studied the Quaternary activity of the GBF and its effects on local hydrogeology. In the shallow subsurface (< 50 m) underneath these scarps, fault splays of the GBF were interpreted on newly acquired ERT profiles at two investigation sites: one on the eastern section and the other on the western section, near the limit of the visible surface trace of the fault. Borehole and CPT data enabled stratigraphic interpretations of the ERT profiles and thereby allowed measuring vertical fault offsets at the base of Pleistocene fluvial deposits of up to 12 m. Groundwater measurements in the boreholes and CPTs indicate that the GBF acts as a hydrologic boundary that prevents groundwater flow from the elevated footwall towards the hangingwall, resulting in hydraulic head differences of up to 12.7 m. For the two investigation sites, the hydraulic head changes correlate with the relief gradient, which in turn correlates with the Quaternary vertical offset of the GBF. ERT profiles at the eastern site also revealed a local soft-linked stepover in the shallow subsurface, which affects groundwater levels in the different fault blocks, and illustrates the complex small-scale geometry of the GBF.

Proof-of-feasibility of using well bore deformation as a diagnostic tool to improve CO₂ sequestration

Energy Technology Data Exchange (ETDEWEB)

Murdoch, Larry [Clemson Univ., SC (United States); Moysey, Stephen [Clemson Univ., SC (United States); Germanovich, Leonid [Georgia Inst. of Technology, Atlanta, GA (United States); Hughes, Baker [Clemson Univ., SC (United States)

2016-01-13

Injecting CO₂ raises pore pressure and this causes subsurface formations to deform. The pattern and amount of deformation will reflect the distribution of pressure and formation properties in the subsurface, two quantities of interest during CO₂ storage. The hypothesis underlying this research is that the small deformation accompanying CO₂ storage can be measured and interpreted to improve the storage process.

The chemistry and saturation states of subsurface fluids during the in situ mineralisation of CO₂ and H₂S at the CarbFix site in SW-Iceland

DEFF Research Database (Denmark)

Snaebjornsdottir, Sandra O.; Oelkers, Eric H.; Mesfin, Kiflom

2017-01-01

is supersaturated prior to and during the mixed gas injection and in the following months. In July 2013, the HN-04 fluid sampling pump broke down due to calcite precipitation, verifying the carbonation of the injected CO2. Mass balance calculations, based on the recovery of non-reactive tracers co......-gas mixture were sequentially injected into basaltic rocks at the CarbFix site at Hellisheidi, SW-Iceland from January to August 2012. This paper reports the chemistry and saturation states with respect to potential secondary minerals of sub-surface fluids sampled prior to, during, and after...

Release of CO{sub 2} and CH{sub 4} from small wetland lakes in western Siberia

Energy Technology Data Exchange (ETDEWEB)

Repo, M.E.; Huttunen, J.T.; Martikainen, P.J. [Univ. of Kuopio, Dept. of Env ironmental Science, FI-70211 Kuopio (Finland); Naumov, A.V.; Chichulin, A.V. [I nst. of Soil Science and Agrochemistry, Russian Academy of Science, 630099 Novos ibirsk (Russian Federation); Lapshina, E.D. [Yugra State Univ., 628012, Khanty-Mansiysk (Russian Federation); Bleuten , W. [Utrecht Univ., Dept. of Physical Geography,3508 TC Utrecht (Netherlands)

2007-11-15

CO{sub 2} and CH{sub 4} fluxes were measured from three small wetland lakes located in the middle taiga and forest tundra zones on West Siberian Lowlands (WSL), the world's largest wetland area. Fluxes were measured during summer 2005 using floating chambers and were validated against the thin boundary layer model based on the relationship between gas exchange and wind speed. All studied lakes were supersaturated with CO{sub 2} and CH{sub 4}, and acted on a seasonal basis as sources of these greenhouse gases to the atmosphere. Daily mean CO{sub 2} fluxes measured with chambers ranged from near the zero to 3.1 g CO{sub 2}/m{sup 2}/d and corresponding CH{sub 4} fluxes from 1.1 to 120 mg CH{sub 4}/m{sup 2}/d. CH{sub 4} ebullition (0.65-11 mg CH{sub 4}/m{sup 2}/d) was detected in two of the lakes. Total carbon evasion from the studied lakes during the active season was 23-66 g C/m{sup 2}, of which more than 90% was released as CO{sub 2}-C. The carbon loss per unit area from the studied lakes was of similar magnitude as previously reported values of net carbon uptake of Siberian peatlands. This emphasizes the importance of small water-bodies in the carbon balance of West Siberian landscape.

Groundwater penetrating radar and high resolution seismic for locating shallow faults in unconsolidated sediments

International Nuclear Information System (INIS)

Wyatt, D.E.

1993-01-01

Faults in shallow, unconsolidated sediments, particularly in coastal plain settings, are very difficult to discern during subsurface exploration yet have critical impact to groundwater flow, contaminant transport and geotechnical evaluations. This paper presents a case study using cross-over geophysical technologies in an area where shallow faulting is probable and known contamination exists. A comparison is made between Wenner and dipole-dipole resistivity data, ground penetrating radar, and high resolution seismic data. Data from these methods were verified with a cone penetrometer investigation for subsurface lithology and compared to existing monitoring well data. Interpretations from these techniques are compared with actual and theoretical shallow faulting found in the literature. The results of this study suggests that (1) the CPT study, combined with the monitoring well data may suggest that discontinuities in correlatable zones may indicate that faulting is present (2) the addition of the Wenner and dipole-dipole data may further suggest that offset zones exist in the shallow subsurface but not allow specific fault planes or fault stranding to be mapped (3) the high resolution seismic data will image faults to within a few feet of the surface but does not have the resolution to identify the faulting on the scale of our models, however it will suggest locations for upward continuation of faulted zones (4) offset 100 MHz and 200 MHz CMP GPR will image zones and features that may be fault planes and strands similar to our models (5) 300 MHz GPR will image higher resolution features that may suggest the presence of deeper faults and strands, and (6) the combination of all of the tools in this study, particularly the GPR and seismic may allow for the mapping of small scale, shallow faulting in unconsolidated sediments

Shallow soil CO2 flow along the San Andreas and Calaveras Faults, California

Science.gov (United States)

Lewicki, J.L.; Evans, William C.; Hilley, G.E.; Sorey, M.L.; Rogie, J.D.; Brantley, S.L.

2003-01-01

We evaluate a comprehensive soil CO2 survey along the San Andreas fault (SAF) in Parkfield, and the Calaveras fault (CF) in Hollister, California, in the context of spatial and temporal variability, origin, and transport of CO2 in fractured terrain. CO2 efflux was measured within grids with portable instrumentation and continously with meteorological parameters at a fixed station, in both faulted and unfaulted areas. Spatial and temporal variability of surface CO2 effluxes was observed to be higher at faulted SAF and CF sites, relative to comparable background areas. However, ??13C (-23.3 to - 16.4???) and ??14C (75.5 to 94.4???) values of soil CO2 in both faulted and unfaulted areas are indicative of biogenic CO2, even though CO2 effluxes in faulted areas reached values as high as 428 g m-2 d-1. Profiles of soil CO2 concentration as a function of depth were measured at multiple sites within SAF and CF grids and repeatedly at two locations at the SAF grid. Many of these profiles suggest a surprisingly high component of advective CO2 flow. Spectral and correlation analysis of SAF CO2 efflux and meteorological parameter time series indicates that effects of wind speed variations on atmospheric air flow though fractures modulate surface efflux of biogenic CO2. The resulting areal patterns in CO2 effluxes could be erroneously attributed to a deep gas source in the absence of isotopic data, a problem that must be addressed in fault zone soil gas studies.

The impact of sedimentary alkalinity release on the water column CO₂ system in the North Sea

OpenAIRE

Brenner, H.; Braeckman, U.; Le Guitton, M.; Meysman, F.J.R.

2016-01-01

It has been previously proposed that alkalinity release from sediments can play an important role in the carbonate dynamics on continental shelves, lowering the pCO2 of seawater and hence increasing the CO2 uptake from the atmosphere. To test this hypothesis, sedimentary alkalinity generation was quantified within cohesive and permeable sediments across the North Sea during two cruises in September 2011 (basin-wide) and June 2012 (Dutch coastal zone). Benthic fluxes of oxyge...

Numerical modeling of CO2 mineralisation during storage in deep saline aquifers

NARCIS (Netherlands)

Ranganathan, P.; Van Hemert, P.; Rudolph, S.J.; Zitha, P.L.J.

2011-01-01

Simulations are performed to evaluate the feasibility of a potential site within the Rotliegend sandstone formation in the Dutch subsurface at a depth of around 3000 m for CO2 sequestration using the numerical simulator CMG-GEM. Three CO2 storage trapping mechanisms are studied: (1) mobility

Characterization of accumulated precipitates during subsurface iron removal

KAUST Repository

Van Halem, Doris

2011-01-01

The principle of subsurface iron removal for drinking water supply is that aerated water is periodically injected into the aquifer through a tube well. On its way into the aquifer, the injected O2-rich water oxidizes adsorbed Fe 2+, creating a subsurface oxidation zone. When groundwater abstraction is resumed, the soluble Fe 2+ is adsorbed and water with reduced Fe concentrations is abstracted for multiple volumes of the injection water. In this article, Fe accumulation deposits in the aquifer near subsurface treatment wells were identified and characterized to assess the sustainability of subsurface iron removal regarding clogging of the aquifer and the potential co-accumulation of other groundwater constituents, such as As. Chemical extraction of soil samples, with Acid-Oxalate and HNO3, showed that Fe had accumulated at specific depths near subsurface iron removal wells after 12 years of operation. Whether it was due to preferred flow paths or geochemical mineralogy conditions; subsurface iron removal clearly favoured certain soil layers. The total Fe content increased between 11.5 and 390.8 mmol/kg ds in the affected soil layers, and the accumulated Fe was found to be 56-100% crystalline. These results suggest that precipitated amorphous Fe hydroxides have transformed to Fe hydroxides of higher crystallinity. These crystalline, compact Fe hydroxides have not noticeably clogged the investigated well and/or aquifer between 1996 and 2008. The subsurface iron removal wells even need less frequent rehabilitation, as drawdown increases more slowly than in normal production wells. Other groundwater constituents, such as Mn, As and Sr were found to co-accumulate with Fe. Acid extraction and ESEM-EDX showed that Ca occurred together with Fe and by X-ray Powder Diffraction it was identified as calcite. © 2010 Elsevier Ltd. All rights reserved.

The thermal impact of subsurface building structures on urban groundwater resources - A paradigmatic example.

Science.gov (United States)

Epting, Jannis; Scheidler, Stefan; Affolter, Annette; Borer, Paul; Mueller, Matthias H; Egli, Lukas; García-Gil, Alejandro; Huggenberger, Peter

2017-10-15

Shallow subsurface thermal regimes in urban areas are increasingly impacted by anthropogenic activities, which include infrastructure development like underground traffic lines as well as industrial and residential subsurface buildings. In combination with the progressive use of shallow geothermal energy systems, this results in the so-called subsurface urban heat island effect. This article emphasizes the importance of considering the thermal impact of subsurface structures, which commonly is underestimated due to missing information and of reliable subsurface temperature data. Based on synthetic heat-transport models different settings of the urban environment were investigated, including: (1) hydraulic gradients and conductivities, which result in different groundwater flow velocities; (2) aquifer properties like groundwater thickness to aquitard and depth to water table; and (3) constructional features, such as building depths and thermal properties of building structures. Our results demonstrate that with rising groundwater flow velocities, the heat-load from building structures increase, whereas down-gradient groundwater temperatures decrease. Thermal impacts on subsurface resources therefore have to be related to the permeability of aquifers and hydraulic boundary conditions. In regard to the urban settings of Basel, Switzerland, flow velocities of around 1 md -1 delineate a marker where either down-gradient temperature deviations or heat-loads into the subsurface are more relevant. Furthermore, no direct thermal influence on groundwater resources should be expected for aquifers with groundwater thicknesses larger 10m and when the distance of the building structure to the groundwater table is higher than around 10m. We demonstrate that measuring temperature changes down-gradient of subsurface structures is insufficient overall to assess thermal impacts, particularly in urban areas. Moreover, in areas which are densely urbanized, and where groundwater flow

A contribution to risk analysis for leakage through abandoned wells in geological CO2 storage

DEFF Research Database (Denmark)

Kopp, Andreas; Binning, Philip John; Johannsen, K.

2010-01-01

2 leakage from subsurface reservoirs. The amounts of leaking CO2 are estimated by evaluating the extent of CO2 plumes after numerically simulating a large number of reservoir realizations with a radially symmetric, homogeneous model To conduct the computationally very expensive simulations, the 'CO2...

Subsurface Nitrogen-Cycling Microbial Communities at Uranium Contaminated Sites in the Colorado River Basin

Science.gov (United States)

Cardarelli, E.; Bargar, J.; Williams, K. H.; Dam, W. L.; Francis, C.

2015-12-01

Throughout the Colorado River Basin (CRB), uranium (U) persists as a relic contaminant of former ore processing activities. Elevated solid-phase U levels exist in fine-grained, naturally-reduced zone (NRZ) sediments intermittently found within the subsurface floodplain alluvium of the following Department of Energy-Legacy Management sites: Rifle, CO; Naturita, CO; and Grand Junction, CO. Coupled with groundwater fluctuations that alter the subsurface redox conditions, previous evidence from Rifle, CO suggests this resupply of U may be controlled by microbially-produced nitrite and nitrate. Nitrification, the two-step process of archaeal and bacterial ammonia-oxidation followed by bacterial nitrite oxidation, generates nitrate under oxic conditions. Our hypothesis is that when elevated groundwater levels recede and the subsurface system becomes anoxic, the nitrate diffuses into the reduced interiors of the NRZ and stimulates denitrification, the stepwise anaerobic reduction of nitrate/nitrite to dinitrogen gas. Denitrification may then be coupled to the oxidation of sediment-bound U(IV) forming mobile U(VI), allowing it to resupply U into local groundwater supplies. A key step in substantiating this hypothesis is to demonstrate the presence of nitrogen-cycling organisms in U-contaminated, NRZ sediments from the upper CRB. Here we investigate how the diversity and abundances of nitrifying and denitrifying microbial populations change throughout the NRZs of the subsurface by using functional gene markers for ammonia-oxidation (amoA, encoding the α-subunit of ammonia monooxygenase) and denitrification (nirK, nirS, encoding nitrite reductase). Microbial diversity has been assessed via clone libraries, while abundances have been determined through quantitative polymerase chain reaction (qPCR), elucidating how relative numbers of nitrifiers (amoA) and denitrifiers (nirK, nirS) vary with depth, vary with location, and relate to uranium release within NRZs in sediment

CO2 removals and CO2 and non-CO2 trace gas emissions affected by human activity in the forests in the Republic of macedonia

International Nuclear Information System (INIS)

Grupche, Ljupcho; Lozanovski, Risto; Markovska, Natasha

2001-01-01

During 2000 and 2001 inventories of CO 2 removals and emissions caused by changes in forest and other woody biomass stocks, as well as the inventories of CO 2 and non-CO 2 trace gas emissions caused by forest conversions (accidental burning) were carried out. According to the forest area in ha, and depending on the differences between the annual biomass increment and annual biomass consumption, about 30-50% of total annual carbon uptake increment is released through the biomass consumption from stocks. 50-70% of the net annual carbon uptake converted to CO 2 identify the annual removals of this gas, which is on average 1805 Gg/yr, ranging between 1485 and 2243 Gg/yr. From 1990 to 1998 on average 4700 ha forest area (min. 110 ha in 1991, max. 14420 ha in 1993) was burned. Proportionally to the burned area, there was a release on average of 18.62 kt C annually (min. 0.42 kt C, max. 57.11 kt), related to 136.07 kt CO 2 on average (min. 1.5 kt CO 2 , max. 209.22 kt CO 2 ). (Original)

Carbon mineralization in surface and subsurface soils in a subtropical mixed forest in central China

Science.gov (United States)

Liu, F.; Tian, Q.

2014-12-01

About a half of soil carbon is stored in subsurface soil horizons, their dynamics have the potential to significantly affect carbon balancing in terrestrial ecosystems. However, the main factors regulating subsurface soil carbon mineralization are poorly understood. As affected by mountain humid monsoon, the subtropical mountains in central China has an annual precipitation of about 2000 mm, which causes strong leaching of ions and nutrition. The objectives of this study were to monitor subsurface soil carbon mineralization and to determine if it is affected by nutrient limitation. We collected soil samples (up to 1 m deep) at three locations in a small watershed with three soil layers (0-10 cm, 10-30 cm, below 30 cm). For the three layers, soil organic carbon (SOC) ranged from 35.8 to 94.4 mg g-1, total nitrogen ranged from 3.51 to 8.03 mg g-1, microbial biomass carbon (MBC) ranged from 170.6 to 718.4 μg g-1 soil. We measured carbon mineralization with the addition of N (100 μg N/g soil), P (50 μg P/g soil), and liable carbon (glucose labeled by 5 atom% 13C, at five levels: control, 10% MBC, 50% MBC, 100% MBC, 200% MBC). The addition of N and P had negligible effects on CO2 production in surface soil layers; in the deepest soil layer, the addition of N and P decreased CO2 production from 4.32 to 3.20 μg C g-1 soil carbon h-1. Glucose addition stimulated both surface and subsurface microbial mineralization of SOC, causing priming effects. With the increase of glucose addition rate from 10% to 200% MBC, the primed mineralization rate increased from 0.19 to 3.20 μg C g-1 soil carbon h-1 (fifth day of glucose addition). The magnitude of priming effect increased from 28% to 120% as soil layers go deep compare to the basal CO2 production (fifth day of 200% MBC glucose addition, basal CO2 production rate for the surface and the deepest soil was 11.17 and 2.88 μg C g-1 soil carbon h-1). These results suggested that the mineralization of subsurface carbon is more

Effects of atmospheric CO2 enrichment on soil CO2 efflux in a young longleaf pine system

Science.gov (United States)

Elevated atmospheric carbon dioxide (CO2) can affect the quantity and quality of plant tissues which will impact carbon (C) cycling and storage in plant/soil systems and the release of CO2 back to the atmosphere. Research is needed to quantify the effects of elevated CO2 on soil CO2 efflux to predi...

Interpretation of 2D Resistivity with Engineering Characterisation of Subsurface Exploration in Nusajaya Johor, Malaysia

Science.gov (United States)

Akip Tan, S. N. Mohd; Dan, M. F. Md; Edy Tonnizam, M.; Saad, R.; Madun, A.; Hazreek, Z. A. M.

2018-04-01

2-D resistivity technique and pole-dipole array with spacing of 2 m electrode and total spacing of 80 m were adopted to map and characterize the shallow subsurface in a sedimentary area at Nusajaya, Johor. Geological field mapping and laboratory testing were conducted to determine weathering grades. Res2Dinv software was used to generate the inversion model resistivity. The result shows sandstone contains iron mineral (30-1000ohm-m) and weathered sandstone (500-1000 ohm-m). The lowest layer represents sandstone and siltstone with the highest range from 1500 through 5000 ohm-m. The weathering grade IV and V of sandstone in the actual profile indicates the range from 30 to 1000 ohm-m, whereas grade II and III in ground mass matched the higest range. Overall, the increase of weathering grade influenced both the physical properties and strength of rocks.

Environmental Responses to Carbon Mitigation through Geological Storage

Energy Technology Data Exchange (ETDEWEB)

Cunningham, Alfred [Montana State Univ., Bozeman, MT (United States); Bromenshenk, Jerry [Montana State Univ., Bozeman, MT (United States)

2013-08-30

In summary, this DOE EPSCoR project is contributing to the study of carbon mitigation through geological storage. Both deep and shallow subsurface research needs are being addressed through research directed at improved understanding of environmental responses associated with large scale injection of CO₂ into geologic formations. The research plan has two interrelated research objectives. Objective 1: Determine the influence of CO₂-related injection of fluids on pore structure, material properties, and microbial activity in rock cores from potential geological carbon sequestration sites. Objective 2: Determine the Effects of CO₂ leakage on shallow subsurface ecosystems (microbial and plant) using field experiments from an outdoor field testing facility.

Wellbore integrity analysis of a natural CO2 producer

KAUST Repository

Crow, Walter; Carey, J. William; Gasda, Sarah; Brian Williams, D.; Celia, Michael

2010-01-01

integrity, defined as the maintenance of isolation between subsurface intervals. In this report, we investigate a 30-year-old well from a natural CO2 production reservoir using a suite of downhole and laboratory tests to characterize isolation performance

Effect of electrochemical corrosion on the subsurface microstructure evolution of a CoCrMo alloy in albumin containing environment

International Nuclear Information System (INIS)

Wang, Zhongwei; Yan, Yu; Su, Yanjing; Qiao, Lijie

2017-01-01

Highlights: • Accelerated electrochemical corrosion results in severer plastic deformation with finer grains. • Lower applied potential can increase protein adsorption on sample surfaces. • The tribo-film decreases the shear stresses and relief subsurface deformation. • Tribocorrosion induced passive film can suppress the annihilation of stacking faults. - Abstract: The subsurface microstructures of metallic implants play a key role in bio-tribocorrosion. Due to wear or change of local environment, the implant surface can have inhomogeneous electrochemical corrosion properties. In this work, the effect of electrochemical corrosion conditions on the subsurface microstructure evolution of CoCrMo alloys for artificial joints was investigated. Transmission electron microscope (TEM) was employed to observe the subsurface microstructures of worn areas at different applied potentials in a simulated physiological solution. The results showed that applied potentials could affect the severity of the subsurface deformation not only by changing the surface passivation but also affecting the adsorption of protein on the alloy surface.

Effect of electrochemical corrosion on the subsurface microstructure evolution of a CoCrMo alloy in albumin containing environment

Energy Technology Data Exchange (ETDEWEB)

Wang, Zhongwei; Yan, Yu, E-mail: yanyu@ustb.edu.cn; Su, Yanjing; Qiao, Lijie

2017-06-01

Highlights: • Accelerated electrochemical corrosion results in severer plastic deformation with finer grains. • Lower applied potential can increase protein adsorption on sample surfaces. • The tribo-film decreases the shear stresses and relief subsurface deformation. • Tribocorrosion induced passive film can suppress the annihilation of stacking faults. - Abstract: The subsurface microstructures of metallic implants play a key role in bio-tribocorrosion. Due to wear or change of local environment, the implant surface can have inhomogeneous electrochemical corrosion properties. In this work, the effect of electrochemical corrosion conditions on the subsurface microstructure evolution of CoCrMo alloys for artificial joints was investigated. Transmission electron microscope (TEM) was employed to observe the subsurface microstructures of worn areas at different applied potentials in a simulated physiological solution. The results showed that applied potentials could affect the severity of the subsurface deformation not only by changing the surface passivation but also affecting the adsorption of protein on the alloy surface.

Hyperspectral Geobotanical Remote Sensing for Monitoring and Verifying CO₂ Containment Final Report CRADA No. TC-2036-02

Energy Technology Data Exchange (ETDEWEB)

Pickles, W. L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ebrom, D. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2017-09-28

This collaborative effort was in support of the CO₂ Capture Project (CCP), to develop techniques that integrate overhead images of plant species, plant health, geological formations, soil types, aquatic, and human use spatial patterns for detection and discrimination of any CO₂ releases from underground storage formations. The goal of this work was to demonstrate advanced hyperspectral geobotanical remote sensing methods to assess potential leakage of CO₂ from underground storage. The timeframes and scales relevant to the long-term storage of CO₂ in the subsurface make remote sensing methods attractive. Moreover, it has been shown that individual field measurements of gas composition are subject to variability on extremely small temporal and spatial scales. The ability to verify ultimate reservoir integrity and to place individual surface measurements into context will be crucial to successful long-term monitoring and verification activities. The desired results were to produce a defined and tested procedure that could be easily used for long-term monitoring of possible CO₂ leakage from underground CO₂ sequestration sites. This testing standard will be utilized on behalf of the oil industry.

Subsurface oxide plays a critical role in CO2 activation by Cu(111) surfaces to form chemisorbed CO2, the first step in reduction of CO2.

Science.gov (United States)

Favaro, Marco; Xiao, Hai; Cheng, Tao; Goddard, William A; Yano, Junko; Crumlin, Ethan J

2017-06-27

A national priority is to convert CO 2 into high-value chemical products such as liquid fuels. Because current electrocatalysts are not adequate, we aim to discover new catalysts by obtaining a detailed understanding of the initial steps of CO 2 electroreduction on copper surfaces, the best current catalysts. Using ambient pressure X-ray photoelectron spectroscopy interpreted with quantum mechanical prediction of the structures and free energies, we show that the presence of a thin suboxide structure below the copper surface is essential to bind the CO 2 in the physisorbed configuration at 298 K, and we show that this suboxide is essential for converting to the chemisorbed CO 2 in the presence of water as the first step toward CO 2 reduction products such as formate and CO. This optimum suboxide leads to both neutral and charged Cu surface sites, providing fresh insights into how to design improved carbon dioxide reduction catalysts.

Second Generation CO2 FEP Analysis: CASSIF - Carbon Storage Scenario Identification Framework

NARCIS (Netherlands)

Yavuz, F.; Tilburg, T. van; David, P.; Spruijt, M.; Wildenborg, T.

2009-01-01

Carbon dioxide Capture and Storage (CCS) is a promising contribution to reduce further increase of atmospheric CO2 emissions from fossil fuels. The CCS concept anticipates that large amounts of CO2 are going to be stored in the subsurface for the long term. Since CCS is a rather new technology,

Detection of Shallow Buried Archaeological Remains Structure using 2-D Resistivity Method at Sungai Batu, Lembah Bujang, Kedah

Science.gov (United States)

Ismail, Nurina; Nordiana, M. M.; Saidin, M.; Masnan, S. S. K.; Abir, I. A.

2018-04-01

In an archaeological study, 2-D resistivity becomes important tools for the scientific investigation and also can be applied to map shallow subsurface structures at the archaeological site. The main purpose of the research is to locate the shallow buried archaeological remains structure in the area of Sungai Batu, Lembah Bujang, Kedah (Malaysia). Resistivity surveys have been applied using a Pole-dipole array with both 5 survey lines for SB1 and SB2 sites using 0.75 m electrode spacing. Both results revealed high resistivity zone with ≥ 3000 Ωm at a depth ranging from 0-1.5 m at the study area. SB1 site conducting an excavation to validate the result obtain while SB2 is not conducting any excavation. Besides that, the other characteristics of the buried archaeological remains are indicated as mound area and there is exposed remain found on top of the surface. Based on the archaeological evidence, the higher resistivity value indicates the interesting anomaly which is clay bricks for archaeological excavation.

Soil CO2 concentrations and efflux dynamics of a tree island in the Pantanal wetland

Science.gov (United States)

Lathuillière, Michael J.; Pinto, Osvaldo B.; Johnson, Mark S.; Jassal, Rachhpal S.; Dalmagro, Higo J.; Leite, Nei K.; Speratti, Alicia B.; Krampe, Daniela; Couto, Eduardo G.

2017-08-01

The Pantanal is the largest tropical wetland on the planet, and yet little information is available on the biome's carbon cycle. We used an automatic station to measure soil CO2 concentrations and oxidation-reduction potential over the 2014 and 2015 flood cycles of a tree island in the Pantanal that is immune to inundation during the wetland's annual flooding. The soil CO2 concentration profile was then used to estimate soil CO2 efflux over the two periods. In 2014, subsurface soil saturation at 0.30 m depth created conditions in that layer that led to CO2 buildup close to 200,000 ppm and soil oxidation-reduction potential below -300 mV, conditions that were not repeated in 2015 due to annual variability in soil saturation at the site. Mean CO2 efflux over the 2015 flood cycle was 0.023 ± 0.103 mg CO2-C m-2 s-1 representing a total annual efflux of 593 ± 2690 mg CO2-C m-2 y-1. Unlike a nearby tree island site that experiences full inundation during the wet season, here the soil dried quickly following repeated rain events throughout the year, which led to the release of CO2 pulses from the soil. This study highlights not only the complexity and heterogeneity in the Pantanal's carbon balance based on differences in topography, flood cycles, and vegetation but also the challenges of applying the gradient method in the Pantanal due to deviations from steady state conditions.

Monitoring underground migration of sequestered CO2 using self-potential methods

Science.gov (United States)

Ishido, T.; Pritchett, J.; Tosha, T.; Nishi, Y.; Nakanishi, S.

2013-12-01

An appropriate monitoring program is indispensable for an individual geologic storage project to aid in answering various operational questions by detecting changes within the reservoir and to provide early warning of potential CO2 leakage through the caprock. Such a program is also essential to reduce uncertainties associated with reservoir parameters and to improve the predictive capability of reservoir models. Repeat geophysical measurements performed at the earth surface show particular promise for monitoring large subsurface volumes. To appraise the utility of geophysical techniques, Ishido et al. carried out numerical simulations of an aquifer system underlying a portion of Tokyo Bay and calculated the temporal changes in geophysical observables caused by changing underground conditions as computed by reservoir simulation (Energy Procedia, 2011). They used 'geophysical postprocessors' to calculate the resulting temporal changes in the earth-surface distributions of microgravity, self-potential (SP), apparent resistivity (from MT surveys) and seismic observables. The applicability of any particular method is likely to be highly site-specific, but these calculations indicate that none of these techniques should be ruled out altogether. Some survey techniques (gravity, MT resistivity) appear to be suitable for characterizing long-term changes, whereas others (seismic reflection, SP) are quite responsive to short term disturbances. The self-potential postprocessor calculates changes in subsurface electrical potential induced by pressure disturbances through electrokinetic coupling (Ishido & Pritchett, JGR 1999). In addition to electrokinetic coupling, SP anomalies may be generated by various other mechanisms such as thermoelectric coupling, electrochemical diffusion potential, etc. In particular, SP anomalies of negative polarity, which are frequently observed near wells, appear to be caused by an underground electrochemical mechanism similar to a galvanic cell

Modeling of CO2 storage in aquifers

International Nuclear Information System (INIS)

Savioli, Gabriela B; Santos, Juan E

2011-01-01

Storage of CO 2 in geological formations is a means of mitigating the greenhouse effect. Saline aquifers are a good alternative as storage sites due to their large volume and their common occurrence in nature. The first commercial CO 2 injection project is that of the Sleipner field in the Utsira Sand aquifer (North Sea). Nevertheless, very little was known about the effectiveness of CO 2 sequestration over very long periods of time. In this way, numerical modeling of CO 2 injection and seismic monitoring is an important tool to understand the behavior of CO 2 after injection and to make long term predictions in order to prevent CO 2 leaks from the storage into the atmosphere. The description of CO 2 injection into subsurface formations requires an accurate fluid-flow model. To simulate the simultaneous flow of brine and CO 2 we apply the Black-Oil formulation for two phase flow in porous media, which uses the PVT data as a simplified thermodynamic model. Seismic monitoring is modeled using Biot's equations of motion describing wave propagation in fluid-saturated poroviscoelastic solids. Numerical examples of CO 2 injection and time-lapse seismics using data of the Utsira formation show the capability of this methodology to monitor the migration and dispersal of CO 2 after injection.

Study of CO2 bubble dynamics in seawater from QICS field Experiment

Science.gov (United States)

Chen, B.; Dewar, M.; Sellami, N.; Stahl, H.; Blackford, J.

2013-12-01

One of the concerns of employing CCS at engineering scale is the risk of leakage of storage CO2 on the environment and especially on the marine life. QICS, a scientific research project was launched with an aim to study the effects of a potential leak from a CCS system on the UK marine environment [1]. The project involves the injection of CO2 from a shore-based lab into shallow marine sediments. One of the main objectives of the project is to generate experimental data to be compared with the developed physical models. The results of the models are vital for the biogeochemical and ecological models in order to predict the impact of a CO2 leak in a variety of situations. For the evaluation of the fate of the CO2 bubbles into the surrounding seawater, the physical model requires two key parameters to be used as input which are: (i) a correlation of the drag coefficient as function of the CO2 bubble Reynolds number and (ii) the CO2 bubble size distribution. By precisely measuring the CO2 bubble size and rising speed, these two parameters can be established. For this purpose, the dynamical characteristics of the rising CO2 bubbles in Scottish seawater were investigated experimentally within the QICS project. Observations of the CO2 bubbles plume rising freely in the in seawater column were captured by video survey using a ruler positioned at the leakage pockmark as dimension reference. This observation made it possible, for the first time, to discuss the dynamics of the CO2 bubbles released in seawater. [1] QICS, QICS: Quantifying and Monitoring Potential Ecosystem Impacts of Geological Carbon Storage. (Accessed 15.07.13), http://www.bgs.ac.uk/qics/home.html

Large-scale CO2 storage — Is it feasible?

Directory of Open Access Journals (Sweden)

Johansen H.

2013-06-01

Full Text Available CCS is generally estimated to have to account for about 20% of the reduction of CO2 emissions to the atmosphere. This paper focuses on the technical aspects of CO2 storage, even if the CCS challenge is equally dependent upon finding viable international solutions to a wide range of economic, political and cultural issues. It has already been demonstrated that it is technically possible to store adequate amounts of CO2 in the subsurface (Sleipner, InSalah, Snøhvit. The large-scale storage challenge (several Gigatons of CO2 per year is more an issue of minimizing cost without compromising safety, and of making international regulations.The storage challenge may be split into 4 main parts: 1 finding reservoirs with adequate storage capacity, 2 make sure that the sealing capacity above the reservoir is sufficient, 3 build the infrastructure for transport, drilling and injection, and 4 set up and perform the necessary monitoring activities. More than 150 years of worldwide experience from the production of oil and gas is an important source of competence for CO2 storage. The storage challenge is however different in three important aspects: 1 the storage activity results in pressure increase in the subsurface, 2 there is no production of fluids that give important feedback on reservoir performance, and 3 the monitoring requirement will have to extend for a much longer time into the future than what is needed during oil and gas production. An important property of CO2 is that its behaviour in the subsurface is significantly different from that of oil and gas. CO2 in contact with water is reactive and corrosive, and may impose great damage on both man-made and natural materials, if proper precautions are not executed. On the other hand, the long-term effect of most of these reactions is that a large amount of CO2 will become immobilized and permanently stored as solid carbonate minerals. The reduced opportunity for direct monitoring of fluid samples

Large-scale CO2 storage — Is it feasible?

Science.gov (United States)

Johansen, H.

2013-06-01

CCS is generally estimated to have to account for about 20% of the reduction of CO2 emissions to the atmosphere. This paper focuses on the technical aspects of CO2 storage, even if the CCS challenge is equally dependent upon finding viable international solutions to a wide range of economic, political and cultural issues. It has already been demonstrated that it is technically possible to store adequate amounts of CO2 in the subsurface (Sleipner, InSalah, Snøhvit). The large-scale storage challenge (several Gigatons of CO2 per year) is more an issue of minimizing cost without compromising safety, and of making international regulations.The storage challenge may be split into 4 main parts: 1) finding reservoirs with adequate storage capacity, 2) make sure that the sealing capacity above the reservoir is sufficient, 3) build the infrastructure for transport, drilling and injection, and 4) set up and perform the necessary monitoring activities. More than 150 years of worldwide experience from the production of oil and gas is an important source of competence for CO2 storage. The storage challenge is however different in three important aspects: 1) the storage activity results in pressure increase in the subsurface, 2) there is no production of fluids that give important feedback on reservoir performance, and 3) the monitoring requirement will have to extend for a much longer time into the future than what is needed during oil and gas production. An important property of CO2 is that its behaviour in the subsurface is significantly different from that of oil and gas. CO2 in contact with water is reactive and corrosive, and may impose great damage on both man-made and natural materials, if proper precautions are not executed. On the other hand, the long-term effect of most of these reactions is that a large amount of CO2 will become immobilized and permanently stored as solid carbonate minerals. The reduced opportunity for direct monitoring of fluid samples close to the

A deeply branching thermophilic bacterium with an ancient acetyl-CoA pathway dominates a subsurface ecosystem.

Directory of Open Access Journals (Sweden)

Hideto Takami

Full Text Available A nearly complete genome sequence of Candidatus 'Acetothermum autotrophicum', a presently uncultivated bacterium in candidate division OP1, was revealed by metagenomic analysis of a subsurface thermophilic microbial mat community. Phylogenetic analysis based on the concatenated sequences of proteins common among 367 prokaryotes suggests that Ca. 'A. autotrophicum' is one of the earliest diverging bacterial lineages. It possesses a folate-dependent Wood-Ljungdahl (acetyl-CoA pathway of CO(2 fixation, is predicted to have an acetogenic lifestyle, and possesses the newly discovered archaeal-autotrophic type of bifunctional fructose 1,6-bisphosphate aldolase/phosphatase. A phylogenetic analysis of the core gene cluster of the acethyl-CoA pathway, shared by acetogens, methanogens, some sulfur- and iron-reducers and dechlorinators, supports the hypothesis that the core gene cluster of Ca. 'A. autotrophicum' is a particularly ancient bacterial pathway. The habitat, physiology and phylogenetic position of Ca. 'A. autotrophicum' support the view that the first bacterial and archaeal lineages were H(2-dependent acetogens and methanogenes living in hydrothermal environments.

A Deeply Branching Thermophilic Bacterium with an Ancient Acetyl-CoA Pathway Dominates a Subsurface Ecosystem

Science.gov (United States)

Takami, Hideto; Noguchi, Hideki; Takaki, Yoshihiro; Uchiyama, Ikuo; Toyoda, Atsushi; Nishi, Shinro; Chee, Gab-Joo; Arai, Wataru; Nunoura, Takuro; Itoh, Takehiko; Hattori, Masahira; Takai, Ken

2012-01-01

A nearly complete genome sequence of Candidatus ‘Acetothermum autotrophicum’, a presently uncultivated bacterium in candidate division OP1, was revealed by metagenomic analysis of a subsurface thermophilic microbial mat community. Phylogenetic analysis based on the concatenated sequences of proteins common among 367 prokaryotes suggests that Ca. ‘A. autotrophicum’ is one of the earliest diverging bacterial lineages. It possesses a folate-dependent Wood-Ljungdahl (acetyl-CoA) pathway of CO2 fixation, is predicted to have an acetogenic lifestyle, and possesses the newly discovered archaeal-autotrophic type of bifunctional fructose 1,6-bisphosphate aldolase/phosphatase. A phylogenetic analysis of the core gene cluster of the acethyl-CoA pathway, shared by acetogens, methanogens, some sulfur- and iron-reducers and dechlorinators, supports the hypothesis that the core gene cluster of Ca. ‘A. autotrophicum’ is a particularly ancient bacterial pathway. The habitat, physiology and phylogenetic position of Ca. ‘A. autotrophicum’ support the view that the first bacterial and archaeal lineages were H2-dependent acetogens and methanogenes living in hydrothermal environments. PMID:22303444

FEASIBILITY OF LARGE-SCALE OCEAN CO2 SEQUESTRATION

Energy Technology Data Exchange (ETDEWEB)

Dr. Peter Brewer; Dr. James Barry

2002-09-30

We have continued to carry out creative small-scale experiments in the deep ocean to investigate the science underlying questions of possible future large-scale deep-ocean CO{sub 2} sequestration as a means of ameliorating greenhouse gas growth rates in the atmosphere. This project is closely linked to additional research funded by the DoE Office of Science, and to support from the Monterey Bay Aquarium Research Institute. The listing of project achievements here over the past year reflects these combined resources. Within the last project year we have: (1) Published a significant workshop report (58 pages) entitled ''Direct Ocean Sequestration Expert's Workshop'', based upon a meeting held at MBARI in 2001. The report is available both in hard copy, and on the NETL web site. (2) Carried out three major, deep ocean, (3600m) cruises to examine the physical chemistry, and biological consequences, of several liter quantities released on the ocean floor. (3) Carried out two successful short cruises in collaboration with Dr. Izuo Aya and colleagues (NMRI, Osaka, Japan) to examine the fate of cold (-55 C) CO{sub 2} released at relatively shallow ocean depth. (4) Carried out two short cruises in collaboration with Dr. Costas Tsouris, ORNL, to field test an injection nozzle designed to transform liquid CO{sub 2} into a hydrate slurry at {approx}1000m depth. (5) In collaboration with Prof. Jill Pasteris (Washington University) we have successfully accomplished the first field test of a deep ocean laser Raman spectrometer for probing in situ the physical chemistry of the CO{sub 2} system. (6) Submitted the first major paper on biological impacts as determined from our field studies. (7) Submitted a paper on our measurements of the fate of a rising stream of liquid CO{sub 2} droplets to Environmental Science & Technology. (8) Have had accepted for publication in Eos the first brief account of the laser Raman spectrometer success. (9) Have had two

Modelling shallow landslide susceptibility by means of a subsurface flow path connectivity index and estimates of soil depth spatial distribution

Directory of Open Access Journals (Sweden)

C. Lanni

2012-11-01

Full Text Available Topographic index-based hydrological models have gained wide use to describe the hydrological control on the triggering of rainfall-induced shallow landslides at the catchment scale. A common assumption in these models is that a spatially continuous water table occurs simultaneously across the catchment. However, during a rainfall event isolated patches of subsurface saturation form above an impeding layer and their hydrological connectivity is a necessary condition for lateral flow initiation at a point on the hillslope.

Here, a new hydrological model is presented, which allows us to account for the concept of hydrological connectivity while keeping the simplicity of the topographic index approach. A dynamic topographic index is used to describe the transient lateral flow that is established at a hillslope element when the rainfall amount exceeds a threshold value allowing for (a development of a perched water table above an impeding layer, and (b hydrological connectivity between the hillslope element and its own upslope contributing area. A spatially variable soil depth is the main control of hydrological connectivity in the model. The hydrological model is coupled with the infinite slope stability model and with a scaling model for the rainfall frequency–duration relationship to determine the return period of the critical rainfall needed to cause instability on three catchments located in the Italian Alps, where a survey of soil depth spatial distribution is available. The model is compared with a quasi-dynamic model in which the dynamic nature of the hydrological connectivity is neglected. The results show a better performance of the new model in predicting observed shallow landslides, implying that soil depth spatial variability and connectivity bear a significant control on shallow landsliding.

Subsurface oil release field experiment - observations and modelling of subsurface plume behaviour

International Nuclear Information System (INIS)

Rye, H.; Brandvik, P.J.; Reed, M.

1996-01-01

An experiment was conducted at sea, in which oil was released from 107 metres depth, in order to study plume behaviour. The objective of the underwater release was to simulate a pipeline leakage without gas and high pressure and to study the behaviour of the rising plume. A numerical model for the underwater plume behaviour was used for comparison with field data. The expected path of the plume, the time expected for the plume to reach the sea surface and the width of the plume was modelled. Field data and the numerical model were in good agreement. 10 refs., 2 tabs., 9 figs

Subsurface clade of Geobacteraceae that predominates in a diversity of Fe(III)-reducing subsurface environments

Science.gov (United States)

Holmes, Dawn E.; O'Neil, Regina A.; Vrionis, Helen A.; N'Guessan, Lucie A.; Ortiz-Bernad, Irene; Larrahondo, Maria J.; Adams, Lorrie A.; Ward, Joy A.; Nicoll , Julie S.; Nevin, Kelly P.; Chavan, Milind A.; Johnson, Jessica P.; Long, Philip E.; Lovely, Derek R.

2007-01-01

There are distinct differences in the physiology of Geobacter species available in pure culture. Therefore, to understand the ecology of Geobacter species in subsurface environments, it is important to know which species predominate. Clone libraries were assembled with 16S rRNA genes and transcripts amplified from three subsurface environments in which Geobacter species are known to be important members of the microbial community: (1) a uranium-contaminated aquifer located in Rifle, CO, USA undergoing in situ bioremediation; (2) an acetate-impacted aquifer that serves as an analog for the long-term acetate amendments proposed for in situ uranium bioremediation and (3) a petroleum-contaminated aquifer in which Geobacter species play a role in the oxidation of aromatic hydrocarbons coupled with the reduction of Fe(III). The majority of Geobacteraceae 16S rRNA sequences found in these environments clustered in a phylogenetically coherent subsurface clade, which also contains a number of Geobacter species isolated from subsurface environments. Concatamers constructed with 43 Geobacter genes amplified from these sites also clustered within this subsurface clade. 16S rRNA transcript and gene sequences in the sediments and groundwater at the Rifle site were highly similar, suggesting that sampling groundwater via monitoring wells can recover the most active Geobacter species. These results suggest that further study of Geobacter species in the subsurface clade is necessary to accurately model the behavior of Geobacter species during subsurface bioremediation of metal and organic contaminants.

The Tiehchanshan structure of NW Taiwan: A potential geological reservoir for CO2 sequestration

Directory of Open Access Journals (Sweden)

Kenn-Ming Yang

2017-01-01

Full Text Available The Tiehchanshan structure is the largest gas-field in the outer foothills of northwestern Taiwan and has been regarded as the best site for CO2 sequestration. This study used a grid of seismic sections and wellbore data to establish a new 3-D geometry of subsurface structure, which was combined with lithofacies characters of the target reservoir rock, the Yutengping Sandstone, to build a geological model for CO2 sequestration. On the surface, the Tiehchanshan structure is characterized by two segmented anticlines offset by a tear fault. The subsurface geometry of the Tiehchanshan structure is, however, composed of two thrust-related anticlines with opposite vergence and laterally increasing fold symmetry toward each other. The folds are softly linked via the transfer zone in the subsurface, implying that the suspected tear fault in the surface transfer zone may not exist in the subsurface. The Yutengping Sandstone is composed of several sandstone units characterized by coarsening-upward cycles. The sandstone member can be further divided into four well-defined sandstone layers, separated by laterally continuous shale layers. In view of the structural and stratigraphic characteristics, the optimum area for CO2 injection and storage is in the structurally high in the northern part of the Tiehchanshan structure. The integrity of the closure and the overlying seal are not disrupted by the pre-orogenic high-angle faults. On the other hand, a thick continuous shale layer within the Yutengping Sandstone isolates the topmost sandy layer from the underlying ones and gives another important factor to the CO2 injection simulation.

Mofettes - Investigation of Natural CO2 Springs - Insights and Methods applied

Science.gov (United States)

Lübben, A.; Leven, C.

2014-12-01

The quantification of carbon dioxide concentrations and fluxes leaking from the subsurface into the atmosphere is highly relevant in several research fields such as climate change, CCS, volcanic activity, or earthquake monitoring. Many of the areas with elevated carbon dioxide degassing pose the problem that under the given situation a systematic investigation of the relevant processes is only possible to a limited extent (e.g. in terms of spatial extent, accessibility, hazardous conditions). The upper Neckar valley in Southwest Germany is a region of enhanced natural subsurface CO2 concentrations and mass fluxes of Tertiary volcanic origin. At the beginning of the twentieth century several companies started industrial mining of CO2. The decreasing productivity of the CO2 springs led to the complete shutdown of the industry in 1995 and the existing boreholes were sealed. However, there are evidences that the reservoir, located in the deposits of the Lower Triassic, started to refill during the last 20 years. The CO2 springs replenished and a variety of different phenomena (e.g. mofettes and perished flora and fauna) indicate the active process of large scale CO2 exhalation. This easy-to-access site serves as a perfect example for a natural analog to a leaky CCS site, including abandoned boreholes and a suitable porous rock reservoir in the subsurface. During extensive field campaigns we applied several monitoring techniques like measurements of soil gas concentrations, mass fluxes, electrical resistivity, as well as soil and atmospheric parameters. The aim was to investigate and quantify mass fluxes and the effect of variations in e.g. temperature, soil moisture on the mass flux intensity. Furthermore, we investigated the effect of the vicinity to a mofette on soil parameters like electrical conductivity and soil CO2 concentrations. In times of a changing climate due to greenhouse gases, regions featuring natural CO2 springs demand to be intensively investigated

Analysing the origin of rain- and subsurface water in seasonal wetlands of north-central Namibia

Science.gov (United States)

Hiyama, Tetsuya; Kanamori, Hironari; Kambatuku, Jack R.; Kotani, Ayumi; Asai, Kazuyoshi; Mizuochi, Hiroki; Fujioka, Yuichiro; Iijima, Morio

2017-03-01

We investigated the origins of rain- and subsurface waters of north-central Namibia’s seasonal wetlands, which are critical to the region’s water and food security. The region includes the southern part of the Cuvelai system seasonal wetlands (CSSWs) of the Cuvelai Basin, a transboundary river basin covering southern Angola and northern Namibia. We analysed stable water isotopes (SWIs) of hydrogen (HDO) and oxygen (H2 18O) in rainwater, surface water and shallow groundwater. Rainwater samples were collected during every rainfall event of the rainy season from October 2013 to April 2014. The isotopic ratios of HDO (δD) and oxygen H2 18O (δ 18O) were analysed in each rainwater sample and then used to derive the annual mean value of (δD, δ 18O) in precipitation weighted by each rainfall volume. Using delta diagrams (plotting δD vs. δ 18O), we showed that the annual mean value was a good indicator for determining the origins of subsurface waters in the CSSWs. To confirm the origins of rainwater and to explain the variations in isotopic ratios, we conducted atmospheric water budget analysis using Tropical Rainfall Measuring Mission (TRMM) multi-satellite precipitation analysis (TMPA) data and ERA-Interim atmospheric reanalysis data. The results showed that around three-fourths of rainwater was derived from recycled water at local-regional scales. Satellite-observed outgoing longwave radiation (OLR) and complementary satellite data from MODerate-resolution Imaging Spectroradiometer (MODIS) and Advanced Microwave Scanning Radiometer (AMSR) series implied that the isotopic ratios in rainwater were affected by evaporation of raindrops falling from convective clouds. Consequently, integrated SWI analysis of rain-, surface and subsurface waters, together with the atmospheric water budget analysis, revealed that shallow groundwater of small wetlands in this region was very likely to be recharged from surface waters originating from local rainfall, which was

Leaching of organic acids from macromolecular organic matter by non-supercritical CO2

Science.gov (United States)

Sauer, P.; Glombitza, C.; Kallmeyer, J.

2012-04-01

The storage of CO2 in underground reservoirs is discussed controversly in the scientific literature. The worldwide search for suitable storage formations also considers coal-bearing strata. CO2 is already injected into seams for enhanced recovery of coal bed methane. However, the effects of increased CO2 concentration, especially on organic matter rich formations, are rarely investigated. The injected CO2 will dissolve in the pore water, causing a decrease in pH and resulting in acidic formation waters. Huge amounts of low molecular weight organic acids (LMWOAs) are chemically bound to the macromolecular matrix of sedimentary organic matter and may be liberated by hydrolysis, which is enhanced by the acidic porewater. Recent investigations outlined the importance of LMWOAs as a feedstock for microbial life in the subsurface [1]. Therefore, injection of CO2 into coal formations may result in enhanced nutrient supply for subsurface microbes. To investigate the effect of high concentrations of dissolved CO2 on the release of LMWOAs from coal we developed an inexpensive high-pressure high temperature system that allows manipulating the partial pressure of dissolved gases at pressures and temperatures up to 60 MPa and 120° C, respectively. In a reservoir vessel, gases are added to saturate the extraction medium to the desired level. Inside the extraction vessel hangs a flexible and inert PVDF sleeve (polyvinylidene fluoride, almost impermeable for gases), holding the sample and separating it from the pressure fluid. The flexibility of the sleeve allows for subsampling without loss of pressure. Coal samples from the DEBITS-1 well, Waikato Basin, NZ (R0 = 0.29, TOC = 30%). were extracted at 90° C and 5 MPa, either with pure or CO2-saturated water. Subsamples were taken at different time points during the extraction. The extracted LMWOAs such as formate, acetate and oxalate were analysed by ion chromatography. Yields of LMWOAs were higher with pure water than with CO2

Aerobic biodegradation potential of subsurface microorganisms from a jet fuel-contaminated aquifer

International Nuclear Information System (INIS)

Aelion, C.M.; Bradley, P.M.

1991-01-01

Current efforts to remediate subsurface contamination have spurred research in the application of in situ bioremediation. In 1975, a leak of 83,000 gallons (314,189 liters) of jet fuel (JP-4) contaminated a shallow water-table aquifer near North Charleston, S.C. Laboratory experiments were conducted with contaminated sediments to assess the aerobic biodegradation potential of the in situ microbial community. Sediments were incubated with 14 C-labeled organic compounds, and the evolution of 14 CO 2 was measured over time. Gas chromatographic analyses were used to monitor CO 2 production and O 2 consumption under aerobic conditions. Results indicated that the microbes from contaminated sediments remained active despite the potentially toxic effects of JP-4. 14 CO 2 was measured from [ 14 C]glucose respiration in unamended and nitrate-amended samples after 1 day of incubation. Total [ 14 C]glucose metabolism was greater in 1 mM nitrate-amended than in unamended samples because of increased cellular incorporation of 14 C label. [ 14 C]benzene and [ 14 C]toluene were not significantly respired after 3 months of incubation. With the addition of 1 mM NO 3 , CO 2 production measured by gas chromatographic analysis increased linearly during 2 months of incubation at a rte of 0.099 μmol g -1 (dry weight) day -1 while oxygen concentration decreased at a rate of 0.124 μmol g -1 (dry weight) day -1 . With no added nitrate, CO 2 production was not different from that in metabolically inhibited control vials. The results suggest that the in situ microbial community is active despite the JP-4 jet fuel contamination and that biodegradation may be compound specific. Also, the community is strongly nitrogen limited, and nitrogen additions may be required to significantly enhance hydrocarbon biodegradation

Auto correlation analysis of coda waves from local earthquakes for detecting temporal changes in shallow subsurface structures - The 2011 Tohoku-Oki, Japan, earthquake -

Science.gov (United States)

Nakahara, H.

2013-12-01

For monitoring temporal changes in subsurface structures, I propose to use auto correlation functions of coda waves from local earthquakes recorded at surface receivers, which probably contain more body waves than surface waves. Because the use of coda waves requires earthquakes, time resolution for monitoring decreases. But at regions with high seismicity, it may be possible to monitor subsurface structures in sufficient time resolutions. Studying the 2011 Tohoku-Oki (Mw 9.0), Japan, earthquake for which velocity changes have been already reported by previous studies, I try to validate the method. KiK-net stations in northern Honshu are used in the analysis. For each moderate earthquake, normalized auto correlation functions of surface records are stacked with respect to time windows in S-wave coda. Aligning the stacked normalized auto correlation functions with time, I search for changes in arrival times of phases. The phases at lag times of less than 1s are studied because changes at shallow depths are focused. Based on the stretching method, temporal variations in the arrival times are measured at the stations. Clear phase delays are found to be associated with the mainshock and to gradually recover with time. Amounts of the phase delays are in the order of 10% on average with the maximum of about 50% at some stations. For validation, the deconvolution analysis using surface and subsurface records at the same stations are conducted. The results show that the phase delays from the deconvolution analysis are slightly smaller than those from the auto correlation analysis, which implies that the phases on the auto correlations are caused by larger velocity changes at shallower depths. The auto correlation analysis seems to have an accuracy of about several percents, which is much larger than methods using earthquake doublets and borehole array data. So this analysis might be applicable to detect larger changes. In spite of these disadvantages, this analysis is

CO2 maximum in the oxygen minimum zone (OMZ

Directory of Open Access Journals (Sweden)

V. Garçon

2011-02-01

Full Text Available Oxygen minimum zones (OMZs, known as suboxic layers which are mainly localized in the Eastern Boundary Upwelling Systems, have been expanding since the 20th "high CO2" century, probably due to global warming. OMZs are also known to significantly contribute to the oceanic production of N2O, a greenhouse gas (GHG more efficient than CO2. However, the contribution of the OMZs on the oceanic sources and sinks budget of CO2, the main GHG, still remains to be established. We present here the dissolved inorganic carbon (DIC structure, associated locally with the Chilean OMZ and globally with the main most intense OMZs (O2−1 in the open ocean. To achieve this, we examine simultaneous DIC and O2 data collected off Chile during 4 cruises (2000–2002 and a monthly monitoring (2000–2001 in one of the shallowest OMZs, along with international DIC and O2 databases and climatology for other OMZs. High DIC concentrations (>2225 μmol kg−1, up to 2350 μmol kg−1 have been reported over the whole OMZ thickness, allowing the definition for all studied OMZs a Carbon Maximum Zone (CMZ. Locally off Chile, the shallow cores of the OMZ and CMZ are spatially and temporally collocated at 21° S, 30° S and 36° S despite different cross-shore, long-shore and seasonal configurations. Globally, the mean state of the main OMZs also corresponds to the largest carbon reserves of the ocean in subsurface waters. The CMZs-OMZs could then induce a positive feedback for the atmosphere during upwelling activity, as potential direct local sources of CO2. The CMZ paradoxically presents a slight "carbon deficit" in its core (~10%, meaning a DIC increase from the oxygenated ocean to the OMZ lower than the corresponding O2 decrease (assuming classical C/O molar ratios. This "carbon deficit" would be related to regional thermal mechanisms affecting faster O2 than DIC (due to the carbonate buffer effect and occurring upstream in warm waters (e.g., in the Equatorial Divergence

Fundamental Understanding of Methane-Carbon Dioxide-Water (CH4-CO2-H2O) Interactions in Shale Nanopores under Reservoir Conditions.

Energy Technology Data Exchange (ETDEWEB)

Wang, Yifeng [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2018-02-01

Shale is characterized by the predominant presence of nanometer-scale (1-100 nm) pores. The behavior of fluids in those pores directly controls shale gas storage and release in shale matrix and ultimately the wellbore production in unconventional reservoirs. Recently, it has been recognized that a fluid confined in nanopores can behave dramatically differently from the corresponding bulk phase due to nanopore confinement (Wang, 2014). CO₂ and H₂O, either preexisting or introduced, are two major components that coexist with shale gas (predominately CH₄) during hydrofracturing and gas extraction. Note that liquid or supercritical CO₂ has been suggested as an alternative fluid for subsurface fracturing such that CO₂ enhanced gas recovery can also serve as a CO₂ sequestration process. Limited data indicate that CO₂ may preferentially adsorb in nanopores (particularly those in kerogen) and therefore displace CH4 in shale. Similarly, the presence of water moisture seems able to displace or trap CH₄ in shale matrix. Therefore, fundamental understanding of CH₄-CO₂-H₂O behavior and their interactions in shale nanopores is of great importance for gas production and the related CO₂ sequestration. This project focuses on the systematic study of CH₄-CO₂-H₂O interactions in shale nanopores under high-pressure and high temperature reservoir conditions. The proposed work will help to develop new stimulation strategies to enable efficient resource recovery from fewer and less environmentally impactful wells.

Pre-stack estimation of time-lapse seismic velocity changes : an example from the Sleipner CO2-sequestration project

International Nuclear Information System (INIS)

Ghaderi, A.; Landro, M.; Ghaderi, A.

2005-01-01

Carbon dioxide (CO 2 ) is being injected into a shallow sand formation at around a 1,000 metre depth at the Sleipner Field located in the North Sea. It is expected that the CO 2 injected in the bottom of the formation, will form a plume consisting of CO 2 accumulating in thin lenses during migration up through the reservoir. Several studies have been published using stacked seismic data from 1994, 1999, 2001 and 2002. A thorough analysis of post-stack seismic data from the Sleipner CO2-Sequestration Pilot Project was conducted. Interpretation of seismic data is usually done on post-stack data. For a given subsurface reflection point, seismic data are acquired for various incidence angles, typically 40 angles. These 40 seismic signals are stacked together in order to reduce noise. The term pre-stack refers to seismic data prior to this step. For hydrocarbon-related 4-dimensional seismic studies, travel time shift estimations have been used. This paper compared pre-stack and post-stack estimation of average velocity changes based on measured 4-dimensional travel time shifts. It is more practical to compare estimated velocity changes than the actual travel time changes, since the time shifts vary with offset for pre-stack time-lapse seismic analysis. It was concluded that the pre-stack method gives smaller velocity changes when estimated between two key horizons. Therefore, pre-stack travel time analysis in addition to conventional post-stack analysis is recommended. 6 refs., 12 figs

Simulating Shallow Soil Response Using Wave Propagation Numerical Modelling in the Western Plain of Taiwan

Directory of Open Access Journals (Sweden)

Chun-Te Chen

2016-06-01

Full Text Available This study used the results from 45 microtremor array measurements to construct a shallow shear wave velocity structure in the western plain of Taiwan. We constructed a complete 3D velocity model based on shallow and tomography models for our numerical simulation. There are three major subsurfaces, engineering bedrock (VS = 600 m s-1, Pliocene formation and Miocene formation, constituted in the shallow model. The constant velocity is given in each subsurface. We employed a 3D-FD (finite-differences method to simulate seismic wave propagation in the western plain. The aim of this study was to perform a quantitative comparison of site amplifications and durations obtained from empirical data and numerical modelling in order to obtain the shallow substructure soil response. Modelling clearly revealed that the shallow substructure plays an important role in strong ground motion prediction using 3D simulation. The results show significant improvements in effective shaking duration and the peak ground velocity (PGV distribution in terms of the accuracy achieved by our developed model. We recommend a high-resolution shallow substructure as an essential component in future seismic hazard analyses.

CO2 maximum in the oxygen minimum zone (OMZ)

Science.gov (United States)

Paulmier, A.; Ruiz-Pino, D.; Garçon, V.

2011-02-01

Oxygen minimum zones (OMZs), known as suboxic layers which are mainly localized in the Eastern Boundary Upwelling Systems, have been expanding since the 20th "high CO2" century, probably due to global warming. OMZs are also known to significantly contribute to the oceanic production of N2O, a greenhouse gas (GHG) more efficient than CO2. However, the contribution of the OMZs on the oceanic sources and sinks budget of CO2, the main GHG, still remains to be established. We present here the dissolved inorganic carbon (DIC) structure, associated locally with the Chilean OMZ and globally with the main most intense OMZs (O2Chile during 4 cruises (2000-2002) and a monthly monitoring (2000-2001) in one of the shallowest OMZs, along with international DIC and O2 databases and climatology for other OMZs. High DIC concentrations (>2225 μmol kg-1, up to 2350 μmol kg-1) have been reported over the whole OMZ thickness, allowing the definition for all studied OMZs a Carbon Maximum Zone (CMZ). Locally off Chile, the shallow cores of the OMZ and CMZ are spatially and temporally collocated at 21° S, 30° S and 36° S despite different cross-shore, long-shore and seasonal configurations. Globally, the mean state of the main OMZs also corresponds to the largest carbon reserves of the ocean in subsurface waters. The CMZs-OMZs could then induce a positive feedback for the atmosphere during upwelling activity, as potential direct local sources of CO2. The CMZ paradoxically presents a slight "carbon deficit" in its core (~10%), meaning a DIC increase from the oxygenated ocean to the OMZ lower than the corresponding O2 decrease (assuming classical C/O molar ratios). This "carbon deficit" would be related to regional thermal mechanisms affecting faster O2 than DIC (due to the carbonate buffer effect) and occurring upstream in warm waters (e.g., in the Equatorial Divergence), where the CMZ-OMZ core originates. The "carbon deficit" in the CMZ core would be mainly compensated locally at the

Potential impacts of leakage from deep CO2 geosequestration on overlying freshwater aquifers.

Science.gov (United States)

Little, Mark G; Jackson, Robert B

2010-12-01

Carbon Capture and Storage may use deep saline aquifers for CO(2) sequestration, but small CO(2) leakage could pose a risk to overlying fresh groundwater. We performed laboratory incubations of CO(2) infiltration under oxidizing conditions for >300 days on samples from four freshwater aquifers to 1) understand how CO(2) leakage affects freshwater quality; 2) develop selection criteria for deep sequestration sites based on inorganic metal contamination caused by CO(2) leaks to shallow aquifers; and 3) identify geochemical signatures for early detection criteria. After exposure to CO(2), water pH declines of 1-2 units were apparent in all aquifer samples. CO(2) caused concentrations of the alkali and alkaline earths and manganese, cobalt, nickel, and iron to increase by more than 2 orders of magnitude. Potentially dangerous uranium and barium increased throughout the entire experiment in some samples. Solid-phase metal mobility, carbonate buffering capacity, and redox state in the shallow overlying aquifers influence the impact of CO(2) leakage and should be considered when selecting deep geosequestration sites. Manganese, iron, calcium, and pH could be used as geochemical markers of a CO(2) leak, as their concentrations increase within 2 weeks of exposure to CO(2).

Subsurface geology off Bombay with paleoclimatic inferences interpreted from shallow seismic profiles

Digital Repository Service at National Institute of Oceanography (India)

Bhattacharya, G.C.; Almeida, F.; Vora, K.H.; Siddiquie, H.N.

High resolution seismic reflection profiles nearshore areas off Bombay provide information on subsurface geology and permit certain paleoclimatic inferences. Three sedimentary units overlie the acoustic basement: late Pleistocene consolidated...

Nitrogen fertilization raises CO2 efflux from inorganic carbon: A global assessment.

Science.gov (United States)

Zamanian, Kazem; Zarebanadkouki, Mohsen; Kuzyakov, Yakov

2018-03-25

Nitrogen (N) fertilization is an indispensable agricultural practice worldwide, serving the survival of half of the global population. Nitrogen transformation (e.g., nitrification) in soil as well as plant N uptake releases protons and increases soil acidification. Neutralizing this acidity in carbonate-containing soils (7.49 × 10 9  ha; ca. 54% of the global land surface area) leads to a CO 2 release corresponding to 0.21 kg C per kg of applied N. We here for the first time raise this problem of acidification of carbonate-containing soils and assess the global CO 2 release from pedogenic and geogenic carbonates in the upper 1 m soil depth. Based on a global N-fertilization map and the distribution of soils containing CaCO 3 , we calculated the CO 2 amount released annually from the acidification of such soils to be 7.48 × 10 12  g C/year. This level of continuous CO 2 release will remain constant at least until soils are fertilized by N. Moreover, we estimated that about 273 × 10 12  g CO 2 -C are released annually in the same process of CaCO 3 neutralization but involving liming of acid soils. These two CO 2 sources correspond to 3% of global CO 2 emissions by fossil fuel combustion or 30% of CO 2 by land-use changes. Importantly, the duration of CO 2 release after land-use changes usually lasts only 1-3 decades before a new C equilibrium is reached in soil. In contrast, the CO 2 released by CaCO 3 acidification cannot reach equilibrium, as long as N fertilizer is applied until it becomes completely neutralized. As the CaCO 3 amounts in soils, if present, are nearly unlimited, their complete dissolution and CO 2 release will take centuries or even millennia. This emphasizes the necessity of preventing soil acidification in N-fertilized soils as an effective strategy to inhibit millennia of CO 2 efflux to the atmosphere. Hence, N fertilization should be strictly calculated based on plant-demand, and overfertilization should be avoided not only