Per Aagaard

• Bojsen-Møller, Jens; Seynnes, Olivier R.; Magnusson, S.P.; Hernæs, Herman; Refsdal, Andreas Skiri & Sironga, J. [Show all 10 contributors for this article] (2025). Jumping performance and muscle–tendon characteristics of Maasai men of East Africa. Scientific Reports. 15. doi: 10.1038/s41598-025-01694-9. Full text in Research Archive
• Kitterød, Nils-Otto; Kværner, Jens; Aagaard, Per; Arustiene, Jurga; Bikše, Jānis & Dagestad, Atle [Show all 16 contributors for this article] (2022). Hydrogeology and groundwater quality in the Nordic and Baltic countries. Hydrology Research. ISSN 1998-9563. 53(7), p. 958–982. doi: 10.2166/nh.2022.018. Full text in Research Archive Show summary

  Groundwater utilization and groundwater quality vary in the Baltic and Nordic countries mainly because of different geological settings. Based on the geology, the countries were treated in the following three groups: (1) Fennoscandian countries (Finland, Sweden, and Norway), (2) Denmark and Baltic countries (Estonia, Latvia, and Lithuania), and (3) Iceland. Most of the utilized groundwater resources are taken from Quaternary deposits, but Denmark and the Baltic countries have in addition, important resources in Phanerozoic rocks. The groundwater quality reflects the residence time of water in the subsurface and the chemical composition of the geological formations. Concentrations of ions in the Fennoscandian bedrock are elevated compared to Iceland, but lower than in Denmark and the Baltic countries. Compared to groundwater in the bedrock, groundwater in Quaternary deposits has usually lower concentrations of dissolved minerals. Unconfined Quaternary aquifers are vulnerable to contamination. Examples from Denmark and the Baltic countries illustrate challenges and successful effects of mitigation strategies for such aquifers related to agricultural application and management of nitrogen. Confined and deeper groundwater is better protected against anthropogenic contamination, but water quality may be affected by harmful compounds caused by geogenic processes (viz, sulfide, arsenic, fluoride, and radon).

• Haile, Beyene Girma; Hansen, Henrik Nygaard; Aagaard, Per & Jahren, Jens (2022). How do chlorite coatings form on quartz surface? Journal of Petroleum Science and Engineering. ISSN 0920-4105. 215. doi: 10.1016/j.petrol.2022.110682. Full text in Research Archive Show summary

  Chlorite-coats on quartz surfaces are ubiquitous in various sedimentary environments. Chlorite-coats shield the surface of quartz from quartz cement overgrowths, thus preserving anomalously high porosity in deeply buried sandstone reservoirs. The inhibition of the quartz cement implies that the chlorite-coats on the surface of quartz grains can significantly influence the physicochemical behavior of the quartz grains. Therefore, failure to notice the initial thin microscale coatings forming during deposition can have serious consequences for modeling several geochemical reactions occurring at liquid-solid interfaces. Despite this huge implication, the fundamental mechanisms involved in chlorite-coat formation is not well understood. Here we present an experimental study to determine the parameters that control chlorite-coat formation on the surface of quartz grains. The batch experiments were conducted in a concoction of quartz and chlorite under different conditions of ionic strength, pH, and presence of humic acid (HA), iron- (Fe) and aluminum (Al) oxides). HA, Fe- and Al oxides are suggested to aid the emplacement of chlorite-coat precursors. At pH 7, the quartz–chlorite and quartz–chlorite–Fe/Al-oxides mixing experiments performed in saline and non-saline solution result in equal chlorite-coat coverages, suggesting neither salinity nor Fe and Al-oxides explain the mechanisms of chlorite-coat formation. At pH 5 and 9, however the chlorite-coat coverage was superior only in saline solution, indicating differences in coat coverage may be caused by variable electrokinetic charge distribution due to the distribution and transport of dissolved salt. The chlorite-coat barely formed in experiments that contain HA in quartz–chlorite mixtures regardless of ionic strength and pH. Against a long-standing notion, the presence of organic matter cannot necessarily be prerequisites for binding chlorite on the surface of quartz grains. The dynamic interactions between solution chemistry and surface chemistry of solid phases (quartz, chlorite, HA, Fe and Al oxides) can result in changing the electrokinetic properties in a region near the solid phases and at mineral-solution interfaces. We therefore propose that the electrokinetic response that arises in heterogeneous systems may explain the mechanisms of chlorite-coat formation.

• Ahmadigoltapeh, Sajjad; Miri, Rohaldin; Aagaard, Per & Hellevang, Helge (2021). Extension of SAFT equation of state for fluids confined in nano-pores of sedimentary rocks using molecular dynamic simulation. Journal of Molecular Liquids. ISSN 0167-7322. 348. doi: 10.1016/j.molliq.2021.118045. Full text in Research Archive Show summary

  Confined fluids in nano-mineral pores show notably different thermodynamic behavior compared with those of the same fluid in bulk. We have extended an equation of state (EoS) inspired by statistical association fluid theory (SAFT) to incorporate the fluid-mineral effect into the pure fluid properties confined in the nanopore. The established EoS is coupled with a Helmholtz free energy contribution which is a function of confinement characteristics: the potential of fluid-mineral interaction, bulk-like density and CF. The novel fitting parameter CF relies on the local properties of confined fluid and measures the density fraction within the layering and bulk-like zones, i.e., . The first-principle molecular dynamics (MD) simulation was utilized to estimate the confinement parameters. At T = 300 K, 350 K, 400 K, and 450 K, the NVT ensemble was applied to simulate slit-pore calcite with a continuous and homogeneous surface in contact with water, with pore widths ranging from 1.5 nm to 5 nm. After running each NVT ensemble for 6 ns, the energy and density of confined water were analyzed, and a deviation was discovered with different behavior from what had previously been reported. Coupling CF parameter with proposed EoS improves the absolute relative errors (ARE) at low temperatures up about 50%, leading to a good agreement between modified SAFT EoS and MD results. The methodology described here may be extended to include a mixture of associating fluids such as those found in oil composition and implemented in all SAFT versions.

• Fazeli, Hossein; Masoudi, Mohammad; Patel, Ravi A.; Aagaard, Per & Hellevang, Helge (2020). Pore-Scale Modeling of Nucleation and Growth in Porous Media. ACS Earth and Space Chemistry. 4(2), p. 249–260. doi: 10.1021/acsearthspacechem.9b00290. Full text in Research Archive
• Helle, Tonje Eide; Aagaard, Per; Nordal, Steinar; Long, Michael & Bazin, Sara (2019). A geochemical, mineralogical and geotechnical characterization of the low plastic, highly sensitive glaciomarine clay at Dragvoll, Norway. AIMS Geosciences. 5(4), p. 704–722. doi: 10.3934/geosci.2019.4.704. Full text in Research Archive Show summary

  The sediments at the NTNU research site Dragvoll, Trondheim, Norway accumulated in seawater close to the glacier front during the Pleistocene-Holocene transition. A comprehensive site investigation and laboratory test program was carried out to characterize the quick clay at Dragvoll. Downsized block samples, mini-blocks, were extracted and tested in the laboratory. Index testing, constant rate of strain oedometer tests and anisotropically consolidated undrained compression tests were carried out on all quick-clay samples. Pore-water chemistry, bulk and clay mineralogy, cation exchange capacity and specific surface area were determined. Resistivity cone-penetration tests and electrical resistivity tomography surveys were carried out and correlated to the laboratory results. With a clay mineralogy dominated by illite and chlorite, the Dragvoll clay is electro-chemically very active. Leaching has diluted the salt content in the pore water to~0.7 g/L, corresponding to a very low soil conductivity of only 20 mS/m. Due to the low salt content and a composition of cations in the pore-water dominated by sodium (85-92%), the repulsive forces between the clay particles are large. Therefore, the clay liquefies when remolded and has a very brittle behavior. The clay is slightly overconsolidated in top, with an overconsolidation ratio decreasing towards 1 at around 6 m depth. Developing new cost-effective ground improvement methods that may also serve as landslide mitigation measures in quick-clay areas is needed. Detailed knowledge on mineralogy and geochemistry is necessary to fully understand the behavior of clays, and in developing effective ground improvement methods by chemical additives. This paper present geochemical, mineralogical and geotechnical data from the quick clay at Dragvoll. A field experiment at Dragvoll showed that potassium chloride can be used as landslide mitigation in quick-clay areas, inhibiting retrogressive landslides and reducing the risk for progressive landslides.

• Moghadam, Javad Naseryan; Nooraiepour, Mohammad; Hellevang, Helge; Mondol, Nazmul Haque & Aagaard, Per (2019). Relative permeability and residual gaseous CO2 saturation in the Jurassic Brentskardhaugen Bed sandstones, Wilhelmøya Subgroup, western central Spitsbergen, Svalbard. Norwegian Journal of Geology. ISSN 2387-5844. 99(2). doi: 10.17850/njg005. Full text in Research Archive Show summary

  This study investigates fluid-flow properties of the low-permeability Brentskardhaugen Bed (Knorringfjellet Formation), Wilhelmøya Subgroup, western central Spitsbergen, Svalbard. To evaluate the two-phase relative permeability of the water-CO2 system, we performed unsteady state core-flooding experiments using deionised water and gaseous CO2. The absolute permeability and residual fluid saturations were also studied. Moreover, a core plug of the Berea sandstone was tested as a reference sample. The core-flooding experiments recorded microDarcy permeability values (0.022–0.039 mD) for various differential pressures (4 to 12 MPa). The poor grain sorting and the abundance of cement were the main factors controlling the low matrix permeabilities. Closure of sub-micron fractures was the likely reason for reduced permeability with increasing effective stresses. The experimental measurements showed that CO2 fractional flow reached unity at relatively low CO2 saturation (approximately 0.35–0.45). The irreducible water saturation and trapped CO2 saturation were 56% and 23%, respectively. The corresponding endpoint CO2 and water relative permeability were 0.18 and 0.47, respectively. The results, therefore, demonstrate low endpoint CO2 saturation and low relative permeability, in addition to high CO2 fractional flow at high water saturation. The trapped CO2 saturation was relatively high, which suggests a high CO2 immobilisation capability of the Wilhelmøya Subgroup sandstones. Moreover, a lower relative permeability was observed for gaseous CO2 compared to published results for supercritical CO2. In addition, the examined core sample showed a higher trapped CO2 saturation and higher endpoint CO2 relative permeability compared with the porous and permeable Berea sandstone.

• Sundal, Anja; Brennwald, Matthias S.; Aagaard, Per & Kipfer, Rolf (2019). Noble gas composition and 3H/3He groundwater ages in the Gardermoen Aquifer, Norway: Improved understanding of flow dynamics as a tool for water management. Science of the Total Environment. ISSN 0048-9697. 660, p. 1219–1231. doi: 10.1016/j.scitotenv.2018.12.456. Full text in Research Archive
• Helle, Tonje Eide & Aagaard, Per (2018). Predicting Required Time Stabilising Quick Clays by Potassium Chloride. Environmental Geotechnics. doi: 10.1680/jenge.17.00032. Full text in Research Archive
• Helle, Tonje Eide; Nordal, Steinar & Aagaard, Per (2018). Improved geotechnical properties in salt-treated highly sensitive landslide-prone clays. Proceedings of the Institution of Civil Engineers : Geotechnical Engineering. ISSN 1353-2618. 171(3), p. 232–242. doi: 10.1680/jgeen.17.00071. Full text in Research Archive
• Helle, Tonje Eide; Aagaard, Per & Nordal, Steinar (2017). Improving the post-failure properties in quick clays by treatment with potassium chloride. In Thakur, Vikas Kumar Singh; L'Heureux, Jean-Sébastien & Locat, Ariane (Ed.), Landslides in Sensitive Clays - From Research to Implementation. Springer. ISSN 9783319564869. p. 45–55. doi: 10.1007/978-3-319-56487-6_4. Full text in Research Archive Show summary

  Installation of salt wells filled with potassium chloride may be used as a ground improvement method in quick-clay hazard areas. The migration of potassium chloride is self-driven by molecular diffusion. The effectiveness of improving the geotechnical properties and the time to do so, depend on hydrogeological conditions at the site, original pore water composition and concentration, adsorbed ions, mineral type, and cation exchange capacity. Increased salt content in the pore water decreases the repulsive forces acting between the mineral surfaces. By decreasing the repulsive forces, the liquid limit and remolded shear strength increase, indicating the improvement of the post-failure properties. The clay particles no longer repel one another, ultimately preventing development of retrogressive landslides.

• Helle, Tonje Eide; Long, Michael; Nordal, Steinar & Aagaard, Per (2017). Effectiveness of resistivity cone penetration tests in salt-treated highly sensitive clay. Proceedings of the Institution of Civil Engineers. Ground improvement. ISSN 1755-0750. 170(3), p. 173–184. doi: 10.1680/jgrim.17.00017. Full text in Research Archive Show summary

  Salt wells filled with potassium chloride may be used as landslide mitigation in highly sensitive quick clays, as the changed pore-water composition permanently improves the remoulded shear strength. To verify improvements, resistivity cone penetration tests were conducted around salt wells installed at Dragvoll, Trondheim, Norway. The cone-test measurements for electric resistivity (or conductivity), tip resistance and pore pressure were combined with the results from laboratory tests on piston-core samples extracted around the wells. Salt content, soil and pore-water conductivity, pore-water composition and geotechnical properties were studied. Quick clay is defined as that having a remoulded shear strength of <0·5 kPa, and the soil conductivity is often <100 mS/m. Increased tip resistance was detected at soil conductivities exceeding 200 mS/m as a result of increased salt content, corresponding to a laboratory-determined remoulded shear strength of 3·5 kPa. At Dragvoll, improved non-quick clay is detected by a normalised tip resistance of 3·5 and a pore-pressure parameter of 0·9. Improved geotechnical properties around salt wells may be verified by cone testing, but a site-specific interpretation model based on geotechnical properties from laboratory tests correlated to cone-test results may be needed.

• Sundal, Anja; Miri, Rohaldin; Hellevang, Helge; Tveranger, Jan; Midtkandal, Ivar & Zuchuat, Valentin [Show all 8 contributors for this article] (2017). Movement of CO 2 charged fluids in low permeability rocks during deformation: migration patterns in the Carmel Formation, Utah. Energy Procedia. 114, p. 4537–4544. doi: 10.1016/j.egypro.2017.03.1570. Full text in Research Archive
• Bergmo, Per Eirik Strand; Emmel, Benjamin; Anthonsen, K.L.; Aagaard, Per; Mortensen, G M & Sundal, Anja (2017). Quality Ranking of the Best CO2 Storage Aquifers in the Nordic Countries. Energy Procedia. 114, p. 4374–4381. doi: 10.1016/j.egypro.2017.03.1589. Full text in Research Archive Show summary

  Ranking of CO2 storage sites in the Nordic countries has previously been reported from the NORDICCS project. The ranking was based on geological characteristics of reservoir and seal, data coverage and safety evaluation of the storage complex. Estimated storage capacity were included but not taken into account in the ranking except if two storage sites were equally ranked. This paper presents a method for evaluating knowledge gaps for a storage site based on characterisation and assessment criteria presented in the EU CCS Directive, and a new updated ranking is presented where knowledge gaps are taken into account.

• Helle, Tonje Eide; Aagaard, Per & Nordal, Steinar (2017). In Situ Improvement of Highly Sensitive Clays by Potassium Chloride Migration. Journal of Geotechnical and Geoenvironmental Engineering. ISSN 1090-0241. 143(10). doi: 10.1061/(ASCE)GT.1943-5606.0001774. Full text in Research Archive Show summary

  Highly sensitive, low-saline clays, termed quick clays, represent a risk for large landslides. An in situ experiment was conducted in which salt wells filled with potassium chloride were installed to study how salt wells can be used to reduce landslide risk. Salt-plume migration and clay volume surrounding the salt wells were investigated by resistivity cone penetration testing (RCPTu), piston samples, conductivity divers, and groundwater samples. Correlating geotechnical properties with pore-water compositions, the remolded shear strength (curcur) was improved beyond 1 kPa when the ratio of the sum of potassium, magnesium, and calcium to the major cations exceeded 20%. The value of curcur increased to approximately 4–8 kPa at a distance of 0.5 m from the wells within 3 years, and the liquidity index (LI) decreased from more than 3.4 to less than 1.2. A minimum diameter of 1.5 m around the wells was stabilized within three years. It is recommended that salt wells be installed at a center-to-center distance of 1.5–2.0 m. The improved postfailure properties (curcur and Atterberg limits) are considered permanent in an engineering timescale because of a lasting pore-water composition that inhibits development of high sensitivity. Salt wells can be installed without substantial disturbance of the soil and can be used as landslide mitigation in quick-clay areas.

• Moghadam, Javad Naseryan; Mondol, Nazmul Haque; Aagaard, Per & Hellevang, Helge (2016). Effective stress law for the permeability of clay-bearing sandstones by the Modified Clay Shell model. Greenhouse Gases: Science and Technology. 6(6), p. 752–774. doi: 10.1002/ghg.1612. Full text in Research Archive Show summary

  In this study, the effective stress law for the permeability of two core plugs selected from Berea (Cleveland Quarries, OH, USA) and Knorringfjellet (Longyearbyen, Svalbard, Norway) sandstones is studied experimentally by measuring the core permeability (k) under varying confining stress (σc) and pore pressures (Pp). The obtained results demonstrate that the permeabilities of the two core plugs decrease with increasing σc or decreasing Pp. The effective stress coefficient for the permeability (αk) values are more than 1.0 for both sandstone core plugs indicating higher sensitivity of the permeability with respect to the applied Pp compared to the applied σc. The previously presented models for calculating αk, such as the Clay Free, Clay Shell, and Clay Particle models, are discussed and a new modified Clay Shell model considering spherical geometry is presented to account for the considerable contrast between the elastic moduli of quartz and clay minerals. The discussed models strongly depend on the magnitude of the considered elastic moduli for the clay minerals. While the Clay Shell and Clay Particle models are capable of describing the observed αk values by considering extremely low elastic moduli for clays, the new modified Clay Shell model is capable of predicting αk values by considering moderate to low values of elastic moduli of clays. The increasing trend of αk values by increasing the σc is discussed and a new correlation based on the observed k values for calculation of αk is presented.

• Sundal, Anja; Nystuen, Johan Petter; Rørvik, Kari-Lise; Dypvik, Henning & Aagaard, Per (2016). The Lower Jurassic Johansen Formation, northern North Sea – Depositional model and reservoir characterization for CO2 storage. Marine and Petroleum Geology. ISSN 0264-8172. 77, p. 1376–1401. doi: 10.1016/j.marpetgeo.2016.01.021. Full text in Research Archive
• Moghadam, Javad Naseryan; Mondol, Nazmul Haque; Aagaard, Per & Hellevang, Helge (2016). Experimental investigation of seismic velocity behavior of CO2 saturated sandstones under varying temperature and pressure conditions. Greenhouse Gases: Science and Technology. 6(6), p. 734–751. doi: 10.1002/ghg.1603. Full text in Research Archive Show summary

  Subsurface storage of CO2 into geological formations is considered an important strategy to mitigate increasing atmospheric CO2. Time-lapse seismic monitoring is an integral component of a geological CO2 sequestration project because the seismic behavior of the rock is a function of both mineralogical composition and pore fluid properties. At the uppermost kilometer of the sedimentary basin, CO2 can be present at gaseous, liquid, and supercritical states, with the supercritical and liquid states preferred in CO2 storage operations due to the higher sweep efficiency. In this study, the seismic velocities [both compressional (Vp) and shear (Vs) waves] of two CO2-saturated sandstone core plugs (Red Wildmoor and Knorringfjellet formations) have been measured under a range of temperatures and pressures in which CO2 phase transitions occur. The experiments were done using a uniaxial hydrostatic cell equipped with seismic wave transmitting and receiving transducers. The experimental investigation illustrated that seismic velocities (both Vp and Vs) decreased until the critical point was reached. Further increases in the CO2 pressure above the critical point led to a gradual increasing of Vp while the Vs remained unchanged. The effect of CO2 on the seismic velocity of the sandstone was compared with the effects of N2 and distilled water at the same conditions. It was further indicated that the seismic velocity changes were mainly connected to significant changes of CO2 density and the corresponding bulk rock moduli over the critical point. The observed velocities are in good agreement with Gassmann-predicted velocities as well as literature data.

• Helle, Tonje Eide; Aagaard, Per; Emdal, Arnfinn & Nordal, Steinar (2016). Monitoring the plume of potassium chloride from wells used as ground improvement in highly sensitive clays, In pursuit of best practice - Conference proceedings. Australian Geomechnics Society. ISSN 9780994626103. doi: 10.1061/(asce)gt.1943-5606.0002030. Full text in Research Archive
• Puig, S.; Calvache, Carlos Duque; Pabst, Thomas & Aagaard, Per (2016). The use of surface geophysics to determine the aquifer characteristics in the folldal mining site, Norway. EarthDoc. doi: 10.3997/2214-4609.201601951. Full text in Research Archive
• Haile, Beyene Girma; Hellevang, Helge; Aagaard, Per & Jahren, Jens (2015). Experimental nucleation and growth of smectite and chlorite coatings on clean feldspar and quartz grain surfaces. Marine and Petroleum Geology. ISSN 0264-8172. 68(Part A), p. 664–674. doi: 10.1016/j.marpetgeo.2015.02.006. Full text in Research Archive
• Hellevang, Helge & Aagaard, Per (2015). Constraints on natural global atmospheric CO2 fluxes from 1860 to 2010 using a simplified explicit forward model. Scientific Reports. 5. doi: 10.1038/srep17352. Full text in Research Archive Show summary

  Land-use changes until the beginning of the 20th century made the terrestrial biosphere a net source of atmospheric carbon. Later, burning of fossil fuel surpassed land use changes as the major anthropogenic source of carbon. The terrestrial biosphere is at present suggested to be a carbon sink, but the distribution of excess anthropogenic carbon to the ocean and biosphere sinks is highly uncertain. Our modeling suggest that land-use changes can be tracked quite well by the carbon isotopes until mid-20th century, whereas burning of fossil fuel dominates the present-day observed changes in the isotope signature. The modeling indicates that the global carbon isotope fractionation has not changed significantly during the last 150 years. Furthermore, increased uptake of carbon by the ocean and increasing temperatures does not yet appear to have resulted in increasing the global gross ocean-to-atmosphere carbon fluxes. This may however change in the future when the excess carbon will emerge in the ocean upwelling zones, possibly reducing the net-uptake of carbon compared to the present-day ocean.

• Sundal, Anja; Miri, Rohaldin; Ravn, Trude & Aagaard, Per (2015). Modelling CO2 migration in aquifers; considering 3D seismic property data and the effect of site-typical depositional heterogeneities. International Journal of Greenhouse Gas Control. ISSN 1750-5836. 39, p. 349–365. doi: 10.1016/j.ijggc.2015.05.021. Full text in Research Archive
• Miri, Rohaldin; Noort, Reinier Van; Aagaard, Per & Hellevang, Helge (2015). New insights on the physics of salt precipitation during injection of CO2 into saline aquifers. International Journal of Greenhouse Gas Control. ISSN 1750-5836. 43, p. 10–21. doi: 10.1016/j.ijggc.2015.10.004. Full text in Research Archive
• Helle, Tonje Eide; Nordal, Steinar; Aagaard, Per & Lied, Ole Kristian (2015). Long-term-effect of potassium chloride treatment on improving the soil behavior of highly sensitive clay – Ulvensplitten, Norway. Canadian geotechnical journal (Print). ISSN 0008-3674. 53(3), p. 410–422. doi: 10.1139/cgj-2015-0077. Full text in Research Archive
• Helle, Tonje Eide; Bryntesen, Rikke Nornes; Amundsen, Helene A.; Emdal, Arnfinn; Nordal, Steinar & Aagaard, Per (2015). Laboratory setup to evaluate the improvement of geotechnical properties from potassium chloride saturation of a quick clay from Dragvoll, Norway. In Côté, Jean; Allard, Michel; Perret, Didier; Fortier, Richard; Potvin, Janelle; St-Laurent, Jean-François; Therrien, Julie; Fortin, Alexis; Locat, Pascal; Tremblay, Hélène; Desgagnés, Priscilla; Locat, Ariane; Castonguay, Vincent & Lepage, Caroline (Ed.), GeoQuebec2015 - Challenges from North to South. Agora Communication Inc.. Full text in Research Archive
• Miri, Rohaldin; Aagaard, Per & Hellevang, Helge (2014). Examination of CO2–SO2 Solubility in Water by SAFT1. Implications for CO2 Transport and Storage. Journal of Physical Chemistry B. ISSN 1520-6106. 118(34), p. 10214–10223. doi: 10.1021/jp505562j. Full text in Research Archive
• Naseryan-Moghadam, Javad; Mondol, Nazmul Haque; Hellevang, Helge; Johnsen, Øistein & Aagaard, Per (2014). Seismic Response of CO2 Saturated Red Wildmoor Sandstone under Varying Temperatures and Pressures. In EAGE2014 (Eds.), Workshop Proceedings. 76th EAGE Conference & Exhibition. European Association of Geoscientists and Engineers (EAGE). ISSN 9789073834903. doi: 10.3997/2214-4609.20140849. Full text in Research Archive
• Anthonsen, K.L.; Aagaard, Per; Bergmo, Per Eirik Strand; Gislason, S.R.; Lothe, Ane Elisabet & Mortensen, G.M. [Show all 7 contributors for this article] (2014). Characterisation and selection of the most prospective CO2 storage sites in the Nordic region. Energy Procedia. 63, p. 4884–4896. doi: 10.1016/j.egypro.2014.11.519. Full text in Research Archive
• Miri, Rohaldin; Hellevang, Helge; Braathen, Alvar & Aagaard, Per (2014). Phase relations in the Longyearbyen CO2 Lab reservoir - forecasts for CO2 injection and migration. Norsk Geologisk Tidsskrift. ISSN 0029-196X. 94(2-3), p. 217–232. Full text in Research Archive
• Hellevang, Helge; Aagaard, Per & Jahren, Jens (2014). Will dawsonite form during CO2 storage? Greenhouse Gases: Science and Technology. 4(2), p. 191–199. doi: 10.1002/ghg.1378. Full text in Research Archive
• Helle, Tonje Eide; Gjengedal, Ingelin; Emdal, Arnfinn; Aagaard, Per & Høydal, Øyvind Armand (2014). Potassium Chloride as Ground Improvement in Quick Clay Areas – A Preliminary Study. In L'Heureux, Jean-Sébastien; Locat, Ariane; Leroueil, Serge; Demers, Denis & Locat, Jacques (Ed.), Landslides in Sensitive Clays - From Geosciences to Risk Management. Springer. ISSN 9789400770782. p. 63–74. doi: 10.1007/978-94-007-7079-9_6. Full text in Research Archive
• Bakari, Said Suleiman; Aagaard, Per; Vogt, Rolf David; Ruden, Fridtjov; Johansen, Ingar & Vuai, Said Ali (2013). Strontium isotopes as tracers for quantifying mixing of groundwater in the alluvial plain of a coastal watershed, south-eastern Tanzania. Journal of Geochemical Exploration. ISSN 0375-6742. 130, p. 1–14. doi: 10.1016/j.gexplo.2013.02.008. Full text in Research Archive
• Anthonsen, K.L.; Aagaard, Per; Bergmo, Per Eirik Strand; Erlström, M.; Faleide, Jan Inge & Gislason, S.R. [Show all 8 contributors for this article] (2013). CO2 storage potential in the Nordic region. Energy Procedia. 37, p. 5080–5092. doi: 10.1016/j.egypro.2013.06.421. Full text in Research Archive
• Hellevang, Helge; Pham, Van Thi Hai & Aagaard, Per (2013). Kinetic modelling of CO2-water-rock interactions. International Journal of Greenhouse Gas Control. ISSN 1750-5836. 15, p. 3–15. doi: 10.1016/j.ijggc.2013.01.027. Full text in Research Archive
• Pham, Van Thi Hai; Riis, Fridtjof; Gjeldvik, I.T.; Halland, E.K.; Tappel, I.M. & Aagaard, Per (2013). Assessment of CO2 injection into the south Utsira-Skade aquifer, the North Sea, Norway. Energy. ISSN 0360-5442. 55, p. 529–540. doi: 10.1016/j.energy.2013.03.026. Full text in Research Archive
• Hellevang, Helge & Aagaard, Per (2013). Can the long-term potential for carbonatization and safe long-term CO2 storage in sedimentary formations be predicted? Applied Geochemistry. ISSN 0883-2927. 39, p. 108–118. doi: 10.1016/j.apgeochem.2013.09.012. Full text in Research Archive
• Baig, Irfan; Aagaard, Per; Sassier, Caroline; Faleide, Jan Inge; Jahren, Jens & Gabrielsen, Roy H. [Show all 10 contributors for this article] (2013). Potential Triassic and Jurassic CO2 Storage Reservoirs in the Skagerrak-Kattegat Area. Energy Procedia. 37, p. 5298–5306. doi: 10.1016/j.egypro.2013.06.447. Full text in Research Archive Show summary

  Regional assessment studies for CO2 storage plays have been carried out in the Norwegian-Danish Basin of the Central North Sea and in the Skagerrak-Kattegat area. The development of the reservoir models is a part of an ongoing interdisciplinary project with the overall goal to establish a basis for large-scale handling of CO2 in this area, including regional CO2 source and capture possibilities, transportation and infrastructure, possible storage sites as well as legal aspects relating to the whole CCS chain. The study shows that all the necessary premises for a safe, long term CO2 storage, are present in the area. Two trap types for storage have been studied more closely: 1) large gently inclined, unfaulted reservoirs in the northern Skagerrak area and 2) dome structures with four-way closures above salt pillows in the Norwegian Danish Basin. We have closely focused on the Upper Triassic-lowermost Jurassic Gassum Formation and the Middle Jurassic Haldager Sand Formation. The current study presents reservoir characteristics of the sandstones of the Gassum and Haldager formations in the Fjerritslev Trough and on the Skagerrak-Kattegat Platform.

• Haugen, Hans Aksel; Aagaard, Per; Kjärstad, Jan; Bergmo, Per Eirik Strand; Nielsen, Lars Henrik & Eldrup, Nils Henrik [Show all 11 contributors for this article] (2013). Infrastructure for CCS in the Skagerrak/Kattegat region, Southern Scandinavia: A feasibility study. Energy Procedia. 37, p. 2562–2569. doi: 10.1016/j.egypro.2013.06.139. Full text in Research Archive
• Bergmo, Per Eirik Strand; Polak, Szczepan; Aagaard, Per; Frykman, Peter; Haugen, Hans Aksel & Bjørnsen, Dag (2013). Evaluation of CO2 storage potential in Skagerrak. Energy Procedia. 37, p. 4863–4871. doi: 10.1016/j.egypro.2013.06.396. Full text in Research Archive
• Pham, Van Thi Hai; Aagaard, Per & Hellevang, Helge (2012). On the potential for CO2 mineral storage in continental flood basalts - PHREEQC batch- and 1D diffusion-reaction simulations. Geochemical Transactions. 13. doi: 10.1186/1467-4866-13-5. Full text in Research Archive Show summary

  Continental flood basalts (CFB) are considered as potential CO2 storage sites because of their high reactivity and abundant divalent metal ions that can potentially trap carbon for geological timescales. Moreover, laterally extensive CFB are found in many place in the world within reasonable distances from major CO2 point emission sources. Based on the mineral and glass composition of the Columbia River Basalt (CRB) we estimated the potential of CFB to store CO2 in secondary carbonates. We simulated the system using kinetic dependent dissolution of primary basalt-minerals (pyroxene, feldspar and glass) and the local equilibrium assumption for secondary phases (weathering products). The simulations were divided into closed-system batch simulations at a constant CO2 pressure of 100 bar with sensitivity studies of temperature and reactive surface area, an evaluation of the reactivity of H2O in scCO2, and finally 1D reactive diffusion simulations giving reactivity at CO2 pressures varying from 0 to 100 bar. Although the uncertainty in reactive surface area and corresponding reaction rates are large, we have estimated the potential for CO2 mineral storage and identified factors that control the maximum extent of carbonation. The simulations showed that formation of carbonates from basalt at 40 C may be limited to the formation of siderite and possibly FeMg carbonates. Calcium was largely consumed by zeolite and oxide instead of forming carbonates. At higher temperatures (60 – 100 C), magnesite is suggested to form together with siderite and ankerite. The maximum potential of CO2 stored as solid carbonates, if CO2 is supplied to the reactions unlimited, is shown to depend on the availability of pore space as the hydration and carbonation reactions increase the solid volume and clog the pore space. For systems such as in the scCO2 phase with limited amount of water, the total carbonation potential is limited by the amount of water present for hydration of basalt.

• Bakari, Said Suleiman; Aagaard, Per; Vogt, Rolf David; Ruden, Fridtjof; Brennwald, M.S. & Johansen, Ingar [Show all 7 contributors for this article] (2012). Groundwater residence time and paleorecharge conditions in the deep confined aquifers of the coastal watershed, South-East Tanzania. Journal of Hydrology. ISSN 0022-1694. 466, p. 127–140. doi: 10.1016/j.jhydrol.2012.08.016. Full text in Research Archive Show summary

  Analysis of radiocarbon and stable isotopes of C, H and O in groundwater samples from the coastal watershed of Southeastern Tanzania is used to decipher the age of groundwater and the climatic conditions at the time of recharge. Radiocarbon dating was corrected on the basis of stable carbon isotope ratios and hydrochemical data. Two main recharge periods are recognised: (1) a recent recharge period with residence times dated to younger than 1.3 ka BP, for the shallow aquifer and some deep groundwater aquifers; and (2) a paleorecharge occurring during the Late Pleistocene to Holocene transition (between 6 and 13 ka BP), for the lower confined aquifer. The climatic excursions (arid and humid phases) identified in this study match well with those identified from studies of paleo-climatic records in Tanzania and East Africa. The oxygen-18 and radiocarbon results show that there is a potential mixing of groundwater of varying ages along flow paths in the coastal aquifer system. This has also been shown by redox parameters in some of the deeper aquifer samples. The data also revealed that there is relatively simple pattern of lateral groundwater flow in the deeper confined aquifer. Isotopic evidence from this study and related studies in paleolimnology improves our knowledge of the past climates. The data suggests that the paleorecharge to the confined aquifer was from inland under wetter climatic conditions than present. Therefore, paleorecharge from the adjacent mountain regions to coastal area like Ifakara, Morogoro and Udzungwa mountains could be important parts of recharge area of the Kimbiji aquifer. However, the hinterland mountains of Dar es Salaam (mainly Pugu, Mkuranga, Ruvu and Kisarawe) could also play an important role in replenishing the Kimbiji coastal aquifers. In contrast, recharge in the shallow unconfined aquifer is characterized by local rainfall and river water infiltration. This study is the first of its kind, assessing fingerprinting of paleoclimates in Southeastern coastal Tanzania using the isotopic composition of deep groundwater aquifers. The freshwater resources in the Neogene aquifer contain paleo-groundwater aquifers that have been mixed with recently-recharged flow systems. Hence, the resources may be sustainable. This study also provides information that may be useful for designing optimum strategies for a sustainable management of groundwater resources in the coastal aquifer, and it testifies to the importance of groundwater as a paleoclimatic archive. Such information is also essential for consideration by modellers in their attempts to simulate the hydrogeological processes in confined aquifers over very long time spans.

• Monjerezi, Maurice; Vogt, Rolf David; Gebru, Asfaw G; Saka, John D.K. & Aagaard, Per (2012). Minor element geochemistry of groundwater from an area with prevailing saline groundwater in Chikhwawa, lower Shire valley (Malawi). Physics and Chemistry of the Earth. ISSN 1474-7065. 50-52, p. 52–63. doi: 10.1016/j.pce.2012.08.011. Full text in Research Archive
• Nielsen, Jacob Lindberg; Aagaard, Per; Bech, Rune Dueholm; Nygaard, Tobias; Hvid, Lars Grøndahl & Wernbom, Mathias [Show all 8 contributors for this article] (2012). Proliferation of myogenic stem cells in human skeletal muscle in response to low-load resistance training with blood flow restriction. Journal of Physiology. ISSN 0022-3751. 590(17), p. 4351–4361. doi: 10.1113/jphysiol.2012.237008. Full text in Research Archive Show summary

  Low-load resistance training with blood flow restriction has been shown to elicit substantial increases in muscle mass and muscle strength; however, the effect on myogenic stem cells (MSCs) and myonuclei number remains unexplored. Ten male subjects (22.8 ± 2.3 years) performed four sets of knee extensor exercise (20% 1RM) to concentric failure during blood flow restriction (BFR) of the proximal thigh (100 mmHg), while eight work-matched controls (21.9 ± 3.0 years) trained without BFR (control, CON). Twenty-three training sessions were performed within 19 days. Maximal isometric knee extensor strength (MVC) was examined pre- and post-training, while muscle biopsies were obtained at baseline (Pre), after 8 days intervention (Mid8) and 3 (Post3) and 10 days (Post10) post training to examine changes in myofibre area (MFA), MSC and myonuclei number. MVC increased by 7.1% (Post5) and 10.6% (Post12) (P < 0.001) with BFR training, while type I and II MFA increased by 38% (Mid8), 35–37% (Post3) and 31–32% (Post10) (P < 0.001). MSCs per myofibre increased with BFR training from 0.10 ± 0.01 (Pre) to 0.38 ± 0.02 (Mid8), 0.36 ± 0.04 (Post3) and 0.25 ± 0.02 (Post10) (P < 0.001). Likewise, myonuclei per myofibre increased from 2.49 ± 0.07 (Pre) to 3.30 ± 0.22 (Mid8), 3.20 ± 0.16 (Post3) and 3.11 ± 0.11 (Post10), (P < 0.01). Although MFA increased in CON at Mid8, it returned to baseline at Post3. No changes in MSC or myonuclei number were observed in CON. This study is the first to show that short-term low-load resistance exercise performed with partial blood flow restriction leads to marked proliferation of myogenic stem cells and resulting myonuclei addition in human skeletal muscle, which is accompanied by substantial myofibre hypertrophy.

• Monjerezi, Maurice; Vogt, Rolf David; Aagaard, Per & Saka, JDK (2012). The hydro-geochemistry of groundwater resources in an area with prevailing saline groundwater, lower Shire Valley, Malawi. Journal of African Earth Sciences. ISSN 0899-5362. 68, p. 67–81. doi: 10.1016/j.jafrearsci.2012.03.012. Full text in Research Archive
• Bakari, Said Suleiman; Aagaard, Per; Vogt, Rolf David; Ruden, Fridtjov; Johansen, Ingar & Vuai, Said Ali (2012). Delineation of groundwater provenance in a coastal aquifer using statistical and isotopic methods, Southeast Tanzania. Environmental Earth Sciences. ISSN 1866-6280. 66(3), p. 889–902. doi: 10.1007/s12665-011-1299-y. Full text in Research Archive
• Haugen, Hans Aksel; Aagaard, Per; Thyberg, Brit Inger; Kjärstad, Jan; Langlet, David & Melaaen, Morten Christian [Show all 13 contributors for this article] (2011). CCS in the Skagerrak/Kattegat area. Energy Procedia. 4, p. 2324–2331. doi: 10.1016/j.egypro.2011.02.123. Full text in Research Archive
• Monjerezi, Maurice; Vogt, Rolf David; Aagaard, Per; Gebru, Asfaw Gebresadik & Saka, John D.K. (2011). Using Sr-87/Sr-86, delta O-18 and delta H-2 isotopes along with major chemical composition to assess groundwater salinization in lower Shire valley, Malawi. Applied Geochemistry. ISSN 0883-2927. 26(12), p. 2201–2214. doi: 10.1016/j.apgeochem.2011.08.003. Full text in Research Archive
• Flaathen, Therese K.; Oelkers, Eric H; Gislason, Sigurdur R. & Aagaard, Per (2011). The effect of dissolved sulphate on calcite precipitation kinetics and consequences for subsurface CO2 storage. Energy Procedia. 4, p. 5037–5043. doi: 10.1016/j.egypro.2011.02.476. Full text in Research Archive
• Alemu, Binyam Lema; Aker, Eyvind; Soldal, Magnus; Johnsen, Øistein & Aagaard, Per (2011). Influence of CO2 on rock physics properties in typical reservoir rock: A CO2 flooding experiment of brine saturated sandstone in a CT-scanner. Energy Procedia. 4, p. 4379–4386. doi: 10.1016/j.egypro.2011.02.390. Full text in Research Archive Show summary

  Laboratory core flooding experiment was run to investigate the joint use of electrical resistivity, ultrasonic velocities and 3D images of fluid distribution to improve current understanding of CO2 and brine behaviour during drainage and imbibition in reservoir rocks. The test specimen was cylindrical Rothbach sandstone measuring 100 mm in length and 38 mm in diameter, with a porosity of 23% and an average permeability of 400 mD. The brine saturated specimen was drained by injecting CO2 and later imbibed with brine while monitoring changes in resistivity and ultrasonic velocity measurements. Actual fluid saturation level and distribution have been mapped simultaneously using X-ray CT scan. CO2 saturation calculations based on CT values showed a steep saturation gradient at start of drainage and the gradient flattened with more CO2 injected into the sample. The ultrasonic compressional velocity (V p) measurements depicted a continuous decrease with increase in CO2 saturation while the resistivity of the sample increased proportionally with increase in CO2 saturation. A CO2 saturation of 53% was achieved at the end of drainage after injection of 20 pore volume (PV) CO2. This resulted in a decrease of V pby 7.2% while the amplitude decreased by as much as 48%. At the end of drainage, the resistivity of the sample increased to 13.9 Ω-m from full brine saturated value of 3.2 Ω-m. During imbibition, the sample was re-saturated close to 100% after 10 PV brine injection. Change in V p due to CO2 saturation level variation was relatively consistent during drainage and imbibition (no hysteresis) where as the resistivity of the sample was more affected by the flooding history resulting in hysteretic variation in resistivity. Resistivity index (RI) values did not show a consistent pattern and a single Archie’s saturation exponent (n) could not be assigned.

• Pham, Van Thi Hai; Maast, Tom Erik; Hellevang, Helge & Aagaard, Per (2011). Numerical modeling including hysteresis properties for CO2 storage in Tubåen formation, Snøhvit field, Barents Sea. Energy Procedia. 4, p. 3746–3753. doi: 10.1016/j.egypro.2011.02.308. Full text in Research Archive

View all works in NVA

• Ahmadigoltapeh, Sajjad; Miri, Rohaldin; Aagaard, Per & Hellevang, Helge (2022). Corrigendum to “Extension of SAFT equation of state for fluids confined in nano-pores of sedimentary rocks using molecular dynamic simulation” [J. Mol. Liquids (348) (2022) 118045] (Journal of Molecular Liquids (2022) 348, (S0167732221027707), (10.1016/j.molliq.2021.118045)). Journal of Molecular Liquids. ISSN 0167-7322. 367. doi: 10.1016/j.molliq.2022.120440. Full text in Research Archive
• Kitterød, Nils-Otto; Kværner, Jens & Aagaard, Per (2022). Nordic Region Hydrogeochemistry. Full text in Research Archive Show summary

  Data compilation of groundwater chemistry and freshwater abstraction documents the importance of groundwater as an economical resource in the Nordic Region. Management of groundwater require chemical monitoring to minimize risks for contamination, and mitigation is needed to identify anthropogenic and geogenic hazards related to groundwater quality (Kitterød et al, 2022). The interaction between groundwater and surface water is crucial for important ecological systems in the Nordic Region, and the impacts of climate change is a big challenge for hydrological and environmental research. The increased net global energy influx has impact on average temperature, seasonality, precipitation, and runoff, but issues related to water quality and groundwater have received less attention. The interaction between surface water and groundwater chemistry is embraced in the term hydrogeochemistry. In this context the geological framework plays a cardinal role in combination with residence time of water in the subsurface. Extensive sampling of hydrogeochemical variables have been undertaken in the Nordic Region and results are made available in public databases. Such data deserve more attention from the research community, and a pertinent challenge is to include geochemical variables in water balance studies and regional hydrological modeling. Reference: Kitterød, N-O, Kværner, J., Aagaard, P, Arustienė, J, de Beer, H, Bikše, J, Dagestad, A, Gundersen, P, Hansen, B, Hjartarson, Á, Karro, E, Klavins, M, Marandi, A, Putys, P, Radienė, R, Retiķe, I, Rossi, P M, and Thorling, L: Hydrogeology and Groundwater Quality in the Nordic Region. Submitted to Hydrology Research, 2022. Keywords: Hydrogeochemsitry; groundwater quality; surface water quality.

• Sundal, Anja; Weber, Ulrich Wolfgang; Kürschner, Wolfgang; Grimstad, Alv Arne; Ruden, Fridtjof & Aagaard, Per [Show all 9 contributors for this article] (2020). Hydrogeological characterization of Holocene deposits in the Svelvik aquifer – implications for reservoir properties. Full text in Research Archive
• Sundal, Anja; Tuttle, Kevin J.; Aagaard, Per; Fikse, Andrea Nymoen; Moe, K.G. & Øvstedal, Jarl (2019). Managing and monitoring dynamic ravinement processes. Full text in Research Archive
• Sundal, Anja; Miri, Rohaldin; Andersen, Odd; Hellevang, Helge; Gregersen, Ulrik & Olivarius, Mette [Show all 14 contributors for this article] (2019). Optimized CO2 storage in sloping aquifers: Estimation of physical and chemical immobilization potential and retardation along migration path in open storage solutions. Full text in Research Archive
• Aagaard, Per; Sena, Clara; Sundal, Anja & French, Helen Kristine (2019). In situ removal of iron and manganese, the Vyredox treatment system at Elverum. Full text in Research Archive
• Sundal, Anja; French, Helen Kristine & Aagaard, Per (2019). Hydrogeology for students and society: outreach integration in education. Full text in Research Archive
• Papadimitrakis, Ioannis; Oppistov, Toril Gilje; Aagaard, Per; Sena, Clara & French, Helen Kristine (2019). The Grindalsmoen aquifer – groundwater flow simulations and protection zone considerations. Full text in Research Archive
• Sundal, Anja; Hellevang, Helge; Olivarius, Mette; Miri, Rohaldin; Nielsen, Lars-Henrik & Gregersen, Ulrik [Show all 10 contributors for this article] (2018). Geological Constraints on the immobilization potential for CO2 in the Gassum Fm. (Skagerrak, Norway). Full text in Research Archive
• Soldal, Magnus; Sauvin, Guillaume; Park, Joonsang; Mannseth, Trond; Tveit, Svenn & Agersborg, Remy [Show all 8 contributors for this article] (2017). Geophysical monitoring for offshore CO2 storage combined with rock physics lab data(based on SUCCESS WP3 final report Geophysics). Full text in Research Archive
• Moghadam, Javad Naseryan; Mondol, Nazmul Haque; Aagaard, Per & Hellevang, Helge (2017). Determination of CO2-Brine relative permeability curves for CO2 storage sandstone reservoirs. Full text in Research Archive
• Bjørlykke, Knut; Jahren, Jens; Mondol, Nazmul Haque; Hellevang, Helge & Aagaard, Per (2017). Mechanical compaction of sand and clay: Constraints from experimental compaction, chemical reactions and fluid flow during burial-An overview. Full text in Research Archive
• Baig, Irfan; Faleide, Jan Inge; Hjelstuen, Berit Oline Blihovde; Sejrup, Hans Petter; Nystuen, Johan Petter & Aagaard, Per [Show all 8 contributors for this article] (2017). Seismic mapping of Quaternary sediment distribution in the central and northern North Sea. Full text in Research Archive
• Barrio, Maria; Stewart, Heather A.; Akhurst, M.; Aagaard, Per; Alcalde, J. & Bauer, Andreas [Show all 26 contributors for this article] (2015). Norway and UK cross-boundary initiative towards a limate motivated drilling operation in the North Sea. Full text in Research Archive
• Haile, Beyene Girma; Xi, Kelai; Jahren, Jens; Aagaard, Per; Bjørlykke, Knut & Hellevang, Helge (2015). Burial Diagenesis in Triassic Sandstones: key to understand reservior quality evolution. Full text in Research Archive
• Haile, Beyene Girma; Xi, Kelai; Jahren, Jens; Aagaard, Per; Bjørlykke, Knut & Hellevang, Helge (2015). Burial diagenesis in Triassic siliciclastic reservoirs of the Barents Sea region. Full text in Research Archive
• Faleide, Jan Inge; Kalani, Mohsen; Sassier, Caroline; Angeli, Matthieu; Ogebule, Oluwakemi Yetunde & Baig, Irfan [Show all 15 contributors for this article] (2015). Caprock research in the CO2Seal project. Full text in Research Archive
• Aagaard, Per (2015). RESERVOIR -activities and focus. Full text in Research Archive
• Hellevang, Helge & Aagaard, Per (2015). Kort oppholdstid for karbon i atmosfæren – bevis mot menneskeskapte utslipp? [Internet]. geoforskning.no. Full text in Research Archive
• Aagaard, Per (2014). Prioriter transport og lagring av CO2 fremfor fangst. [Internet]. Climit.no. Full text in Research Archive
• Aagaard, Per (2014). NORDICCS. Full text in Research Archive
• Moghadam, Javad Naseryan; Mondol, Nazmul Haque; Hellevang, Helge; Johnsen, Øistein & Aagaard, Per (2014). Seismic response of CO2 saturated Red Wildmoor Sandstone under varying temperatures and pressures. EarthDoc. Full text in Research Archive
• Sundal, Anja; Hellevang, Helge; Miri, Rohaldin & Aagaard, Per (2014). On layer specific CO2 plume distributions and variability in mineralization potential. Full text in Research Archive
• Sundal, Anja; Aagaard, Per; Wejden, Bente & Brennwald, Matthias (2014). 3H/3He dating of groundwater for calibration of flow models. Full text in Research Archive
• Naseryan-Moghadam, Javad; Aagaard, Per; Mondol, Nazmul Haque & Hellevang, Helge (2013). Determination of the Biot’s coefficient for the permeability of DeGeerdalen and Knorringfjellet sandstones, two consolidated formations for CO2 sequestration in Svalbard area. Full text in Research Archive
• Sundal, Anja; Aagaard, Per; Wejden, Bente & Brennwald, Matthias (2013). Flow dynamics and 3H/3He ages of deep groundwater at Gardermoen. Full text in Research Archive
• Sundal, Anja; Miri, Rohaldin; Nystuen, Johan Petter; Dypvik, Henning & Aagaard, Per (2013). Geologic controls on CO2 injectivity and distribution in the Johansen Formation, northern North Sea. Full text in Research Archive
• Baig, Irfan; Aagaard, Per; Fawad, Manzar; Sassier, Caroline; Faleide, Jan Inge & Jahren, Jens [Show all 10 contributors for this article] (2013). Reservoir Characterization of Potential Triassic and Jurassic Reservoirs for CO2 Storage in the Skagerrak-Kattegat Area. Full text in Research Archive
• Sundal, Anja; Miri, Rohaldin; Nystuen, Johan Petter; Dypvik, Henning & Aagaard, Per (2013). Modeling CO2 distribution in a heterogeneous sandstone reservoir: the Johansen Formation, northern North Sea. Full text in Research Archive
• Sassier, Caroline; Jarsve, Erlend Morisbak; Baig, Irfan; Heeremans, Michel; Faleide, Jan Inge & Gabrielsen, Roy H. [Show all 7 contributors for this article] (2013). Salt Tectonics in the Norwegian-Danish Basin - Implications on trap and depositional systems. Full text in Research Archive
• Hellevang, Helge; Jahren, Jens; Haile, Beyene Girma & Aagaard, Per (2013). On the kinetics of digenetic reactions – Diffusion /transport limitations on the K-feldspar to illite conversion during burial diagenesis. Full text in Research Archive
• Moghadam, Javad Naseryan; Mondol, Nazmul Haque & Aagaard, Per (2012). Evaluation of Mechanical Strength of a Barents Sea Shale by Applying the Most Common Failure Criteria. EarthDoc. Full text in Research Archive
• Sundal, Anja; Nystuen, Johan Petter; Dypvik, Henning; Miri, Rohaldin & Aagaard, Per (2012). Effects of geological heterogeneity on CO2 distribution and migration – A case study from the Johansen Formation, Norway. doi: 10.1016/j.egypro.2013.06.418. Full text in Research Archive Show summary

  In characterizing subsurface reservoirs for CO2 storage, the geological heterogeneity distribution is of importance with respect to the injectivity and migration paths. The object of this study is a saline aquifer of Jurassic age; the Johansen Formation of the Northern North Sea. Through scenario modeling the effect of site-typical geological heterogeneities of depositional origin have been tested. The existence of laterally continuous calcite cemented layers and draping mud layers of low permeability in association with flooding events, could compartmentalize the reservoir. This is not necessarily a disadvantage; however, as the sweep efficiency becomes higher when the plume is spread out, potentially increasing the effect of trapping mechanisms.

• Baig, Irfan; Aagaard, Per; Sassier, Caroline; Faleide, Jan Inge; Jahren, Jens & Gabrielsen, Roy H. [Show all 10 contributors for this article] (2012). Potential Triassic and Jurassic CO2 storage reservoirs in the Skagerrak-Kattegat area. Full text in Research Archive
• Sassier, Caroline; Jarsve, Erlend Morisbak; Kalani, Mohsen; Heeremans, Michel; Faleide, Jan Inge & Aagaard, Per [Show all 7 contributors for this article] (2012). Effects of salt tectonics on potential CO2 reservoir and caprock in the Norwegian-Danish Basin. Full text in Research Archive
• Bojsen-Møller, Jens; Losnegard, Thomas; Hallén, Jostein; Aagaard, Per; Kanstrup, Inge-Lis & Kalliokoski, Kari K. [Show all 7 contributors for this article] (2012). Assessment Of Muscle Use With Surface Electromyography And Positron Emission Tomography. Medicine & Science in Sports & Exercise. ISSN 0195-9131. 44, p. 546–546. Full text in Research Archive
• Bergmo, Per Eirik Strand; Polak, Szczepan; Aagaard, Per; Frykman, Peter; Haugen, Hans Aksel & Bjørnsen, Dag (2012). Evaluation of CO2 storage potential in Skagerak. Full text in Research Archive
• Haugen, Hans Aksel; Aagaard, Per; Kjärstad, Jan; Bergmo, Per Eirik Strand; Nielsen, Lars Henrik & Eldrup, Nils Henrik [Show all 11 contributors for this article] (2012). Infrastructure for CCS in the Skagerak/Kattegat region, Southern Scandinavia: A feasibility study. Full text in Research Archive
• Anthonsen, K.L.; Aagaard, Per; Bergmo, Per Eirik Strand; Erlström, M.; Fareide, J.I. & Gislason, Sigurdur R. [Show all 8 contributors for this article] (2012). CO2 storage potential in the Nordic region. Full text in Research Archive
• Baig, Irfan; Aagaard, Per; Fawad, Manzar; Sassier, Caroline; Faleide, Jan Inge & Jahren, Jens [Show all 9 contributors for this article] (2012). Potential Triassic and Jurassic CO2 storage reservoirs in the Skagerrak area. Full text in Research Archive
• Hellevang, Helge; Alemu, Binyam Lema & Aagaard, Per (2011). Mobilization of elements by CO2-mineral interactions. Full text in Research Archive
• Bjørlykke, Knut; Hellevang, Helge & Aagaard, Per (2011). Konsekvensene av surere hav.Noen geokjemiske betraktninger av betydning for livet i havet. Biologen. 2, p. 28–34. Full text in Research Archive
• Pham, Van Thi Hai; Hellevang, Helge & Aagaard, Per (2011). On the potential for CO2 mineral storage in continental flood basalts. Full text in Research Archive
• Alemu, Binyam Lema; Aagaard, Per & Hellevang, Helge (2011). Effect of temperature and mineralogical composition on the reactivity of shale: A comparison study of potential caprock from two potential CO2 storage sites. Full text in Research Archive
• Aagaard, Per; Hellevang, Helge; Alemu, Binyam; Pham, Van T.H. & Sundal, Anja (2011). Potential for mineral trapping during CO2 storage in sedimentary basins. Full text in Research Archive
• Miri, Rohaldin; Hellevang, Helge; Aagaard, Per; Kvamme, Bjørn; Skurtveit, Elin & Wangen, Magnus (2018). Critical Factors for Considering CO2 Injectivity in Saline Aquifers [FME SUCCESS Synthesis report Volume 3]. SUCCESS [Christian Michelsen Research AS]. Full text in Research Archive
• Miri, Rohaldin; Hellevang, Helge; Aagaard, Per & Wangen, Magnus (2015). Effects of CO2-Brine-Rock Interactions on CO2 Injectivity – Implications for CCS. Universitetet i Oslo. Full text in Research Archive Show summary

  Carbon capture and storage (CCS) in geological reservoirs – especially saline aquifers – is a key midterm solution to mitigate climate changes caused by increasing anthropogenic CO2. In order to ensure that a CCS project reach the required level of success, three essential elements need to be guaranteed; storage capacity, injectivity and containment. Among these elements, relatively less research has been conducted relevant to the injectivity, thus there are several technical uncertainties in this regard that should be understood and quantified in order to ensure long-term storage of CO2. This thesis is therefore centered at improving such knowledge and understanding by addressing some of the vague research areas in regard to CO2 injectivity including: CO2/H2O mutual solubilities, salt precipitation and depositional heterogeneities. First part of this study is devoted to thermodynamic modeling of fluid mixtures relevant for CO2 storage with particular focus on effect of methane (CH4) and sulphur dioxide (SO2) impurities. To do this, a molecular based framework, Statistical Association Fluid Theory (SAFT) is chosen and the molecular parameters required by the model were adjusted against the available experimental data. The developed model is effectively used to predict phase partitioning, the aqueous phase density and water drop-out in contact with solid surface, which we believe to be especially well-suited to the assessment of injectivity of a proposed CO2 storage reservoir. In the next part of this thesis, the processes of drying-out and salting-out were explored in more detail. This work encompasses the fabrication of the two sets of glass microchips, as well as series of experimental characterisation that has given us a valuable insight into the mechanism of salt precipitation. In particular, we have identified two mechanisms which together dramatically intensify the precipitation rate and amount of salt precipitated. From this insight, the reported discrepancies in the literature regarding the salt precipitation could be successfully explained and a new prototype for modeling of the process could be provided. We have also studied, but to a lesser extend, the effect of prepositional heterogeneities on the plume migration and pressure response at the injection well. We came to the conclusion that extreme well and aquifer pressures are unlikely for the setting studied in this thesis.

• Vogt, Rolf David; Aagaard, Per & Bakari, Said Suleiman (2012). Chemistry and Hydrogeological Processes in a Coastal Watershed, South-East Tanzania. Faculty of Mathematics and Natural Sciences, University of Oslo. Full text in Research Archive
• Vogt, Rolf David; Aagaard, Per; Saka, John D.K. & Monjerezi, Maurice (2012). Groundwater salinity in lower Shire River valley (Malawi): Hydro-geochemical and isotope constraints on sources and evolution. Faculty of Mathematics and Natural Sciences, University of Oslo. Full text in Research Archive

View all works in NVA