Anja Sundal

• Holden, Nora; Osmond, Johnathon L.; Mulrooney, Mark Joseph; Braathen, Alvar; Skurtveit, Elin & Sundal, Anja (2022). Structural characterization and across-fault seal assessment of the Aurora CO<inf>2</inf> storage site, northern North Sea. Petroleum Geoscience. ISSN 1354-0793. 28(4). doi: 10.1144/petgeo2022-036. Fulltekst i vitenarkiv
• Meneguolo, Renata; Sundal, Anja; Martinius, Allard W.; Veselovsky, Zbynek; Cullum, Alex & Milovanova, Elvira (2022). Impact of the lower Jurassic Dunlin Group depositional elements on the Aurora CO<inf>2</inf> storage site, EL001, northern North Sea, Norway. International Journal of Greenhouse Gas Control. ISSN 1750-5836. 119. doi: 10.1016/j.ijggc.2022.103723.
• Masoudi, Mohammad; Sundal, Anja & Hellevang, Helge (2021). Estimation of Mutual Solubility of CO2-H2O in Saline Aquifer Systems Using ePC-SAFT Equation of State. I Røkke, Nils Anders & Knuutila, Hanna K (Red.), TCCS–11. CO2 Capture, Transport and Storage. Trondheim 22nd–23rd June 2021. Short Papers from the 11th International Trondheim CCS Conference. SINTEF akademisk forlag. ISSN 978-82-536-1714-5.
• Weber, Ulrich Wolfgang; Kampman, Niko & Sundal, Anja (2021). Techno-Economic Aspects of Noble Gases as Monitoring Tracers. Energies. ISSN 1996-1073. 14(12). doi: 10.3390/en14123433. Fulltekst i vitenarkiv
• Weber, Ulrich Wolfgang; Kampman, Niko & Sundal, Anja (2021). On the Distinctiveness of Noble Gases in Injected Co2 from Background Fluids . I Røkke, Nils Anders & Knuutila, Hanna K (Red.), TCCS–11. CO2 Capture, Transport and Storage. Trondheim 22nd–23rd June 2021. Short Papers from the 11th International Trondheim CCS Conference. SINTEF akademisk forlag. ISSN 978-82-536-1714-5. s. 182–187.
• Skurtveit, E.; Torabi, Anita; Sundal, Anja & Braathen, A. (2021). The role of mechanical stratigraphy on CO<inf>2</inf> migration along faults – examples from Entrada Sandstone, Humbug Flats, Utah, USA. International Journal of Greenhouse Gas Control. ISSN 1750-5836. 109. doi: 10.1016/j.ijggc.2021.103376. Fulltekst i vitenarkiv
• Andersen, Odd & Sundal, Anja (2021). Estimating Caprock Impact on CO2 Migration in the Gassum Formation Using 2D Seismic Line Data. Transport in Porous Media. ISSN 0169-3913. 138, s. 459–487. doi: 10.1007/s11242-021-01622-1. Fulltekst i vitenarkiv Vis sammendrag

  Realizable CO2 storage potential for saline formations without closed lateral boundaries depends on the combined effects of physical and chemical trapping mechanisms to prevent long-term migration out of the defined storage area. One such mechanism is the topography of the caprock surface, which may retain CO2 in structural pockets along the migration path. Past theoretical and modeling studies suggest that even traps too small to be accurately described by seismic data may play a significant role. In this study, we use real but scarce seismic data from the Gassum Formation of the Norwegian Continental shelf to estimate the impact of topographical features of the top seal in limiting CO2 migration. We seek to estimate the amount of macro- and sub-scale trapping potential of the formation based on a few dozen interpreted 2D seismic lines and identified faults. We generate multiple high-resolution realizations of the top surface, constructed to be faithful to both large-scale topography and small-scale statistical properties. The structural trapping and plume retardation potential of these top surfaces is subsequently estimated using spill-point (static) analysis and dynamical flow simulation. By applying these techniques on a large ensemble of top surface realizations generated using a combination of stochastic realizations and systematic variation of key model parameters, we explore the range of possible impacts on plume advancement, physical trapping and migration direction. The stochastic analysis of trapping capacity and retardation efficiency in statistically generated, sub-seismic resolution features may also be applied for surfaces generated from 3D data.

• Weber, Ulrich Wolfgang; Kipfer, Rolf; Horstmann, Edith; Ringrose, Philip; Kampman, Niko & Tomonaga, Yama [Vis alle 8 forfattere av denne artikkelen] (2021). Noble gas tracers in gas streams at Norwegian CO2 capture plants. International Journal of Greenhouse Gas Control. ISSN 1750-5836. 106. doi: 10.1016/j.ijggc.2020.103238. Vis sammendrag

  Carbon capture and storage (CCS) may play a significant role in reducing greenhouse gas emissions. Noble gases are potential tracers to monitor subsurface CO2 storage sites and verify their containment. Naturally occurring noble gases have been used successfully to refute alleged CO2 leakage in the past. We present results from several sampling campaigns at two Norwegian CO2 capture facilities, the demonstration plant Technology Centre Mongstad (TCM) and the natural gas processing plant with CO2 capture and storage on Melkøya. The gas streams in the capture plants were monitored with a combination of on-site mass spectrometry and subsequently analysed discrete samples. This allows us to define the factors controlling noble gas concentrations in captured CO2, to monitor temporal variation of noble gas concentrations and finally evaluate the potential to use noble gases as inherent environmental tracers for labelling CO2 in storage reservoirs. At both sites, CO2 is captured using amine gas treatment. Noble gas concentrations in the gas streams were observed to decrease by several orders of magnitude during the processing. Isotopic ratios are air-like for CO2 captured after natural gas combustion at TCM and natural gas-like for CO2 captured from natural gas processing on Melkøya. Further, we detected a solubility trend caused by the amine solvent at TCM with higher solubility for heavier noble gases. We find that the relative concentrations of noble gases in the captured CO2 are defined by the gas from which the CO2 is captured and the design of the amine gas treatment process. Both factors were observed to cause temporal variation in the captured CO2. Using mixing and noble gas partitioning calculations we show that the significant depletion in noble gas concentrations, together with degassing of noble gas enriched formation water, means that the injected CO2 will inherit the noble gas signature of the storage formation, even following the injection of significant CO2 volumes. Any CO2 leaked from the storage formation is thus likely to have a crustal noble gas signature, characteristic of the storage site, which can be targeted for monitoring.

• Braathen, Alvar; Petrie, Elizabeth; Nystuen, Tonje; Sundal, Anja; Midtkandal, Ivar & Skurtveit, Elin [Vis alle 7 forfattere av denne artikkelen] (2020). Interaction of deformation bands and fractures during progressive strain in monocline - San Rafael Swell, Central Utah, USA. Journal of Structural Geology. ISSN 0191-8141.
• Parvin, Saeed; Masoudi, Mohammad; Sundal, Anja & Miri, Rohaldin (2020). Continuum scale modelling of salt precipitation in the context of CO2 storage in saline aquifers with MRST compositional. International Journal of Greenhouse Gas Control. ISSN 1750-5836. 99. doi: 10.1016/j.ijggc.2020.103075. Fulltekst i vitenarkiv
• Braathen, Alvar; Petrie, Elisabeth; Nystuen, Tonje; Sundal, Anja; Skurtveit, Elin & Zuchuat, Valentin [Vis alle 8 forfattere av denne artikkelen] (2020). Interaction of deformation bands and fractures during progressive strain in monocline - San Rafael Swell, Central Utah, USA. Journal of Structural Geology. ISSN 0191-8141. 141. doi: 10.1016/j.jsg.2020.104219. Fulltekst i vitenarkiv
• Skurtveit, Elin; Sundal, Anja; Bjørnarå, Tore Ingvald; Soldal, Magnus; Sauvin, Guillaume & Zuchuat, Valentin [Vis alle 8 forfattere av denne artikkelen] (2020). Experimental investigation of natural fracture stiffness and flow properties in a faulted CO2 bypass system (Utah, USA). Journal of Geophysical Research (JGR): Solid Earth. ISSN 2169-9313. 125(7). doi: 10.1029/2019JB018917. Fulltekst i vitenarkiv Vis sammendrag

  Fracture stiffness and flow properties have been measured in the laboratory using naturally fractured fault rock samples from the Little Grand Wash fault, Utah, USA. We compare fracture closure and related flow change during isotropic loading of two fractures which have been subject to various amounts of paleo‐reactive flow. The two tested fractures are described as (i) a small‐aperture fracture (0.1 mm) with negligible geochemical alterations of the fracture surface and (ii) a large‐aperture fracture (0.53 mm) where precipitates are observed on the fracture surface. X‐ray imaging is used for quantification of fracture aperture and fracture surface contact distribution. The petrographical characterisation using scanning electron microscopy and x‐ray powder diffraction is performed pre‐test and describes burial and uplift diagenesis as well as pulses of reactive fluid flow within the fault. The stress dependent flow and deformation experiment provides new data on fracture stiffness and flow for naturally developed fractures in siliciclastic rock. Fracture stiffness is found to be highest for the small‐aperture fracture due to its high fracture contact ratio and well‐developed surface mating during closure. For the naturally altered and rougher, large‐aperture fracture, fracture stiffness is lower and a highly stress dependent decay in flow is observed during initial closure. The results illustrate that a natural fracture with high contact ratio and well mated surfaces will close during loading, whereas a fracture associated with high flow rates and affected by previous geochemical alteration maintains a high flow rate compared to the host rock during similar loading.

• Zuchuat, Valentin; Midtkandal, Ivar; Poyatos More, Miquel; Da Costa, Sigrid; Brooks, Hannah Louise & Halvorsen, Kristine [Vis alle 9 forfattere av denne artikkelen] (2019). Composite and diachronous stratigraphic surfaces in low-gradient, transitional settings: The J-3 “unconformity” and the Curtis Formation, east-central Utah, U.S.A. Journal of Sedimentary Research. ISSN 1527-1404. 89(11), s. 1075–1095. doi: 10.2110/jsr.2019.56. Fulltekst i vitenarkiv Vis sammendrag

  Unconformities, by definition, correspond to erosional or nondepositional surfaces, which separate older strata below, from younger rocks above, encapsulating significant time gaps. However, recent studies have highlighted the composite nature of some unconformities, as well as their heterochronous and diachronous character, which challenge the use of such a definition in a four-dimensional dynamic environment. The J-3 Unconformity, separating the Middle Jurassic Entrada Sandstone from the Upper Jurassic Curtis Formation (and laterally equivalent units) in east-central Utah (USA), is laterally variable, generated by either erosion-related processes such as eolian deflation, and water-induced erosion, or by deformational processes. The J-3 Unconformity is a composite surface, formed by numerous processes that interacted and overlapped spatially and temporally. This study therefore demonstrates the heterochronous, diachronous, and non-unique nature of this surface interpreted as unconformity, where one process can be represented by varying expressions in the stratigraphic record, and conversely many processes may result in the same stratigraphic expression.

• Olivarius, Mette; Sundal, Anja; Weibel, Rikke; Gregersen, Ulrik; Baig, Irfan & Thomsen, T.B. [Vis alle 9 forfattere av denne artikkelen] (2019). Provenance and sediment maturity as controls on CO2 mineral sequestration potential of the Gassum Formation in Skagerrak. . Frontiers in Earth Science. ISSN 2296-6463. 7. doi: 10.3389/feart.2019.00312. Fulltekst i vitenarkiv
• Sundal, Anja & Hellevang, Helge (2019). Using Reservoir Geology and Petrographic Observations to Improve CO2 Mineralization Estimates; Examples from the Johansen Formation, North Sea, Norway. Minerals. ISSN 2075-163X. 9(11). doi: 10.3390/min9110671. Fulltekst i vitenarkiv
• 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, s. 1219–1231. doi: 10.1016/j.scitotenv.2018.12.456.
• Elenius, Maria; Skurtveit, Elin; Yarushina, Viktoriya M.; Baig, Irfan; Sundal, Anja & Wangen, Magnus [Vis alle 13 forfattere av denne artikkelen] (2018). Assessment of CO2 storage capacity based on sparse data: Skade Formation. International Journal of Greenhouse Gas Control. ISSN 1750-5836. 79, s. 252–271. doi: 10.1016/j.ijggc.2018.09.004. Fulltekst i vitenarkiv Vis sammendrag

  Large North Sea aquifers of high quality are the likely major target for 12 Gt of European CO2 emissions that should be stored in the subsurface by 2050. This involves an upscaling of the present combined injection rate from all European projects, which requires careful examination of the storage feasibility. Many aquifers are closed or semi-closed, with storage capacity mainly constrained by consideration of caprock failure criteria. Because the induced overpressure can propagate to sensitive regions far from the injector, the risk of caprock failure must be examined in terms of large volumes and for long times. This poses challenges with respect to fluid-flow simulation in the presence of highly uncertain aquifer properties. In this work, experts on geology, geophysics, geomechanics and simulation technique collaborate to optimize the use of existing data in an efficient simulation framework. The workflow is applied to the large North Sea Skade Formation, with potential for secondary storage and pressure dissipation in the overlying Utsira Formation. Injection at three locations in Skade gives an overall practical capacity of 1–6 Gt CO2 injected over a 50-year period, depending on the reservoir permeability and compressibility. The capacity is limited by local pressure buildup around wells for the lowest estimated reservoir permeability, and otherwise by regional pressure buildup in shallow zones far from the injection sites. Local deformation of clay due to viscoelastoplastic effects do not have an impact on leakage from the aquifer, but these effects may modify the properties of clay layers within the aquifer, which reduces the risk of lateral compartmentalization. Uplift of the seafloor does not impose constraints on the capacity beyond those set by pressure buildup.

• 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. ISSN 1876-6102. 114, s. 4374–4381. doi: 10.1016/j.egypro.2017.03.1589. Fulltekst i vitenarkiv

Se alle arbeider i Cristin

• Skurtveit, Elin; Petrie, Elizabeth S.; Smith, Scott Adam; Faleide, Thea Sveva; Sundal, Anja & Choi, Jung Chan [Vis alle 10 forfattere av denne artikkelen] (2023). Core analysis from Little Grand Wash fault, Utah, and application for fault risk assessment for co2 storage in the Norwegian North Sea. Vis sammendrag

  Fault zones contain a mixture of lithologies, various fault structures, and evidence for fluid-rock interaction events, representing a record of multiple deformation events during the faulting history. The resulting complex and highly variable mixture of properties makes faults challenging structures to model, and specifically assessing the fault zone permeability and probability of reactivation is difficult. The ability of fault zones to transport fluids has received renewed attention during the last 10 years of developing subsurface, geological storage reservoirs for CO2. The North Sea sedimentary basin offshore Norway has an enormous potential for storing CO2. However, to qualify fault traps in saline aquifers for storage, improved workflows for fault risk assessment focusing on fault zone flow properties and mechanical stability is needed. An improved approach for fault modelling is under development: we quantify the uncertainties in fault rock properties to address the probability of failure and subsequent changes in permeability. To support our understanding of subsurface faults in the North Sea, we utilize knowledge from the Little Grand Wash (LGW) fault, located in Emery County, Utah. The LGW fault zone provides a natural laboratory to study fault zone development in geological analogues, failure mechanisms, and fluid migration. As a supplement to already published well data and core descriptions from this area, three new cores were retrieved from the fault in 2019. In total 16.5 meters of core, covering both the hanging wall (Jurassic Brushy Basin Member of the Morrison Formation) and footwall (Jurassic Summerville Formation) damage zone, have been logged and sampled for petrophysical analysis and mechanical testing. The current work presents new data on variation of permeability, porosity, strength, and sonic velocity inside the fault damage zone, including measurements on different lithologies, various types of cementation and selected deformation bands, fractures, and veins. Petrophysical and chemical analysis combined with visual identification of oil stains and bleaching provide the possibility for a holistic understanding of the system and we derive valuable knowledge for improving fault risk workflows applicable for CO2 storage projects in the Norwegian North Sea.

• Holden, Nora; Osmond, Johnathon L.; Mulrooney, Mark Joseph; Skurtveit, Elin; Sundal, Anja & Braathen, Alvar (2023). Structural characterization and across-fault seal assessment of the Aurora CO2 storage site.
• Holden, Nora; Osmond, Johnathon; Mulrooney, Mark Joseph; Skurtveit, Elin; Braathen, Alvar & Sundal, Anja (2022). Influence of faults on Co2 migration.
• Holden, Nora; Osmond, Johnathon L.; Mulrooney, Mark Joseph; Skurtveit, Elin; Braathen, Alvar & Sundal, Anja (2022). Structural characterization and across-fault seal assessment of the Aurora CO2 storage site, northern North Sea .
• Holden, Nora; Osmond, Johnathon L.; Mulrooney, Mark Joseph; Skurtveit, Elin; Braathen, Alvar & Sundal, Anja (2022). Structural characterization and across-fault seal assessment of the Aurora CO2 storage site, northern North Sea.
• Sundal, Anja (2021). Hydrogeologi “sett” fra verdensrommet – bruk av satellittdata I forvaltning og til overvåking av grunnvannsressurser.
• Sundal, Anja; Meneguolo, Renata & Hellevang, Helge (2021). CO2 storage – dynamic trapping mechanisms due to mineralization. .
• Holden, Nora; Osmond, Johnathon L.; Mulrooney, Mark Joseph; Skurtveit, Elin; Braathen, Alvar & Sundal, Anja (2021). Structural characterization and across-fault seal assessment of the Aurora CO2 storage site.
• Sundal, Anja; Aage, Stangeland & Bru, Tina (2021). Fra lab til langskip. [Internett]. www.youtube.com/watch?v=9BcR6SFCUTg. Vis sammendrag

  Videoen "Fra lab til langskip" ble produsert av Gyro for Gassnova/CLIMIT, og presentert på CLIMIT Digit 10.02.2021 Tina Bru, Aage Stangeland og Anja Sundal intervjues. Videoen ligger tilgjengelig her: www.youtube.com/watch?v=9BcR6SFCUTg

• Holden, Nora; Osmond, Johnathon L.; Mulrooney, Mark Joseph; Skurtveit, Elin; Braathen, Alvar & Sundal, Anja (2021). Across-fault seal assessment of the Aurora CO2 storage site, northern North Sea.
• Sundal, Anja (2021). Design of a mobile, cost-effective monitoring tool for CO2 storage sites on the Norwegian shelf.
• Sundal, Anja & Weber, Ulrich Wolfgang (2021). Applicability of noble gas tracers in Norwegian CO2 capture and storage schemes. The ICO2P project. .
• Holden, Nora; Osmond, Johnathon L.; Mulrooney, Mark Joseph; Skurtveit, Elin; Braathen, Alvar & Sundal, Anja (2021). Structural characterization and across-fault seal assessment of the Aurora CO2 storage site, northern North Sea.
• Sundal, Anja; Meneguolo, Renata; Kruber, Claudia; Olsen, Elin & Hellevang, Helge (2021). Geological site assessment: geochemical review of the Aurora Storage Complex, Northern Lights project, North Sea.
• Sundal, Anja & Weber, Ulrich Wolfgang (2021). Applicability of noble gas tracers in Norwegian CO2 capture and storage schemes.
• Weber, Ulrich Wolfgang; Kampman, Niko; Mikoviny, Tomas; Thomassen, Jorgen & Sundal, Anja (2021). Noble Gases as Monitoring Tracers in CCS: A Case study with CO2 from the Waste-To-Energy Plant Klemetsrud, Norway.
• Zuchuat, Valentin; Midtkandal, Ivar; Poyatos More, Miquel; Da Costa, Sigrid; Brooks, Hannah Louise & Halvorsen, Kristine [Vis alle 9 forfattere av denne artikkelen] (2021). Mind The Gap: Composite and diachronous stratigraphic surfaces in low-gradient, transitional settings: The J-3 “unconformity” and the Curtis Formation, east-central Utah, U.S.A.
• Holden, Nora; Osmond, Johnathon L.; Mulrooney, Mark Joseph; Sundal, Anja & Skurtveit, Elin (2021). Structural characterization of the Aurora prospect, a potential CO2 storage site in the northern North Sea. Vis sammendrag

  Significant uncertainties occur through varying methodologies when interpreting faults using seismic data. These uncertainties are carried through to the interpretation of how faults may act as baffles/barriers or increase fluid flow. How fault segments are picked when interpreting structures, i.e. what seismic line spacing is specified, as well as what surface generation algorithm is used, will dictate how detailed the surface is, and hence will impact any further interpretation such as fault seal or fault growth models. We can observe that an optimum spacing for fault interpretation for this case is set at approximately 100 m. It appears that any additional detail through interpretation with a line spacing of ≤50 m simply adds further complexities, associated with sensitivities by the individual interpreter. Hence, interpreting at a finer scale may not necessarily improve the subsurface model and any related analysis, but in fact lead to the production of very rough surfaces, which impacts any further fault analysis. Interpreting on spacing greater than 100 m often leads to overly smoothed fault surfaces that miss details that could be crucial, both for fault seal as well as for fault growth models. This contribution is a case example showing how different picking strategies influence analysis of a bounding fault in terms of CO2 storage assessment. This is an example from the Horda Plaform: the Smeaheia potential storage site, 20 km East of Troll East. This is a fault bound prospect, and hence this bounding fault is required to have a high seal potential and a low chance of reactivation upon CO2 injection, increasing the pore pressure. Uncertainty in the seismic interpretation methodology will follow through to fault seal analysis, specifically for analysis of whether in situ stresses combined with increased pressure through CO2 injection will act to reactivate the faults, leading to up-fault fluid flow / seep. We have shown that changing picking strategies significantly alter the interpreted stability of the fault, where picking with an increased line spacing has shown to increase the overall fault stability. Surprisingly, differences in picking strategy show little influence on the overall fault seal (i.e. shale gouge ratio) of the fault.

• Sundal, Anja (2020). Geologisk lagring av CO2 . Vis sammendrag

  Foredragene ble filmet, og ligger tilgjengelige her: https://youtu.be/o5AwDGwjIns

• Sundal, Anja (2020). Geologisk CO2-lagring – trygg og effektiv utslippsreduksjon.
• Sundal, Anja (2020). Hvordan karbon kan lagres trygt i stein.
• Sundal, Anja (2020). Prospectivity of noble gas tracers in CCS monitoring schemes.
• Sundal, Anja; Weber, Ulrich Wolfgang; Kürschner, Wolfgang; Grimstad, Alv Arne; Ruden, Fridtjof & Aagaard, Per [Vis alle 9 forfattere av denne artikkelen] (2020). Hydrogeological characterization of Holocene deposits in the Svelvik aquifer – implications for reservoir properties.
• Revheim, Maiken Kristiansen; Weber, Ulrich Wolfgang; Hagby, Klaus Falk; Ringstad, Cathrine & Sundal, Anja (2020). Tidal effect on pressure in upper and lower aquifer of the Svelvik Ridge.
• Weber, Ulrich Wolfgang; Sundal, Anja; Hellevang, Helge & Kipfer, Rolf (2020). Experiences from the ICO2P Project applied to Migration Monitoring of Injected CO2.
• Weber, Ulrich Wolfgang; Heeschen, Katja; Zimmer, Martin; Raphaug, Martin Hagen; Hagby, Klaus Falk & Ringstad, Cathrine [Vis alle 7 forfattere av denne artikkelen] (2020). Tracer Design and Gas Monitoring of a CO2 Injection Experiment at the ECCSEL CO2 Field Lab, Svelvik, Norway.
• Weber, Ulrich Wolfgang; Raphaug, Martin Hagen; Revheim, Maiken & Sundal, Anja (2020). Gas Composition of the Svelvik Ridge Aquifers Used to Design Noble Gas Tracers for a CO2 Injection Experiment.
• Røyne, Anja; Samset, Bjørn Hallvard; Sundal, Anja; Storelvmo, Trude & Joner, Erik (2020). Boklansering: Varm klode, kaldt hode. Løsninger på klimakrisen.
• Andersen, Odd & Sundal, Anja (2020). Using 2D seismic line data to estimate the possible impact of large-scale and sub-scale structural trapping in the Gassum Formation on the Norwegian Continental Shelf.
• Zuchuat, Valentin; Midtkandal, Ivar; Poyatos More, Miquel; Da Costa, Sigrid; Brooks, Hannah L & Halvorsen, Kristine [Vis alle 9 forfattere av denne artikkelen] (2020). Brexit, Megxit, and the J-3 Unconformitexit: how they all lost it. Vis sammendrag

  Unconformities, by definition, correspond to non-depositional or erosive surfaces, separating older strata below, from younger rocks above, and encapsulating significant time gaps. However, recent studies have emphasized the composite nature of some unconformities, as well as their heterochronous and diachronous character, which restricts the use of such a definition to a near one-dimensional setting. This study analyses the nature of the J-3 Unconformity, which separates the Middle Jurassic Entrada Sandstone from the Late Jurassic Curtis Formation (and laterally equivalent units) in east-central Utah (USA). Our detailed mapping and characterization indicates the J-3 “Unconformity” is in fact a composite surface generated by either erosion-related processes such as eolian deflation, and water-induced erosion, or by deformational processes. These multiple mechanisms interacted and overlapped in time and space, which demonstrates the composite and diachronous and non-unique nature of such boundaries. This contact has been historically interpreted as an unconformity, but our results show that this key stratigraphic surface is a time-transgressive flooding-ravinement surface that formed shortly before and during a series of transgressions that flooded the area during the Late Jurassic. Consequently, the regionally extensive, composite, heterochronous, and diachronous J-3 Unconformity does not fit the classic unconformity definition, after which an unconformity universally separates older from younger strata basin-wide. The J3 “Unconformity” case study highlights the fact that one process can be represented by varying expressions in the stratigraphic record, and conversely many processes may result in the same stratigraphic expression. Consequently a revised definition of unconformity is discussed, focusing on processes and associated environmental changes, while abandoning its time-barrier aspect. This investigation also exemplifies some of the implications on subsurface analyses that the inaccurate characterization of the subseismic complex characters of such major stratigraphic bounding surfaces can have. These inaccuracies may lead to imprecise timing and sediment budget predictions, and ultimately have strong implications for basin evolution and reservoir models. Key words: Unconformity, transitional basin, composite surface, ravinement, time-transgressive

• Zuchuat, Valentin; Hafner, Alison; Osmond, Johnathon L.; Liberty, Lee; Petrie, Elizabeth & Arvesen, Brock [Vis alle 11 forfattere av denne artikkelen] (2020). CO2 containment and monitoring techniques along Little Grand Wash Fault, east-central Utah, USA. Vis sammendrag

  Our current understanding of sub-surface CO2 storage feasibility derives mainly from valuable small-scale projects, which have mostly been working at injection or human time scales. These projects, however, have not been operational long enough to fully assess flow and/or seepage at longer time scales relevant for subsurface CO2 sequestration (e.g. > 10 kY). Many examples of fluid escape have been documented in the offshore subsurface environment (e.g. seismic chimneys), and active or relict natural seeps on land offer informative analogues to subsurface fluid migration. Of note are the natural seeps located in east-central Utah, USA that are easily accessible and represent suitable onshore counterparts to the offshore fluid escape features. These seeps can be studied to improve our understanding of geological and geomechanical factors controlling subsurface CO2 containment and the expression of fluid escape in geophysical images. A critical concern in CCS is how to account for features that are detrimental to subsurface storage containment and are at scales below seismic resolution. This multidisciplinary project aims to address the challenge by collecting surface and subsurface datasets at mesoscopic scales that, through upscaling, will be implemented in seismic investigations and reservoir-seal models. The project builds upon previous studies detailing the complex development of the Jurassic sedimentary basin in question (Zuchuat et al. 2018; 2019a; 2019b) but is also relevant for analogous settings such as the Norwegian Continental Shelf (e.g. Horda Platform region). Overall, this next research phase specifically focuses on the detailed, post-depositional history of the targeted interval in Utah, addressing one fundamental question: what are the thresholds for detecting CO2 seeps in the subsurface? This encompasses more targeted questions: • What does the fault core and the fault damage zone of the leaking Little Grand Wash Fault consist of? • What is the detailed geological footprint of CO2 flow along strata, faults, and fractures? • How did the CO2 flow migrate through a heterogeneous and transitional, faulted reservoir-seal complex? • Can seepage from the storage compartments and fluid saturation be identified by seismic imaging? Zuchuat, V., Sleveland, A. R., Sprinkel, D. A., Rimkus, A., Braathen, A., & Midtkandal, I. (2018). New Insights on the Impact of Tidal Currents on a Low-gradient, Semi-enclosed, Epicontinental Basin—the Curtis Formation, East-central Utah, USA. Geology of the Intermountain West, 5, 131-165. Zuchuat, V., Sleveland, A.R.N., Pettigrew, R.P, Dodd, T.J.H., Clarke, S.M., Braathen, A., & Midtkandal, I. (2019a). Overprinted Allocyclic Processes by Tidal Resonance in an Epicontinental Basin: the Upper Jurassic Curtis Formation, East-Central Utah, USA. The Depositional Record, 5(2), 272-305. Zuchuat, V., Midtkandal, I., Poyatos-Moré, M., Da Costa, S., Brooks, H.L., Halvorsen, K., Cote, N., Sundal, A., & Braathen, A. (2019b). Composite and Diachronous Stratigraphic Surfaces in Low-Gradient, Transitional Settings: the J-3 “Unconformity” and the Curtis Formation, East-Central Utah, U.S.A. Accepted in The Journal of Sedimentary Research.

• Anell, Ingrid Margareta; Backer, Dag; Sundal, Anja; Torvanger, Asbjørn; Meisingset, Egil & Rørvik, Kari-Lise [Vis alle 7 forfattere av denne artikkelen] (2019). Feasibility of CO2 storage as a climate mitigation measure in Norway.
• Zuchuat, Valentin; Osmond, Johnathon L.; Sundal, Anja; Midtkandal, Ivar; Skurtveit, Elin & Petrie, Elizabeth [Vis alle 9 forfattere av denne artikkelen] (2019). CO2 containment and monitoring techniques along Little Grand Wash Fault, east-central Utah, USA. Vis sammendrag

  Our current understanding of sub-surface CO2 sequestration feasibility derives mainly from valuable small-scale projects, which have mostly been working at injection or human time scales. These projects, however, have not been operational long enough to fully assess flow and/or seepage at longer time scales relevant for subsurface CO2 storage (e.g. > 10 kY). Many examples of fluid escape have been documented in the offshore subsurface environment (e.g. seismic chimneys), and natural seeps found on land, both active and relict, offer informative analogues to subsurface fluid migration. Of note are the natural seeps located in east-central Utah, USA that are easily accessible and represent suitable onshore counterparts to the offshore fluid escape features. These seeps can improve our understanding of geological and geomechanical factors controlling subsurface CO2 containment and the expression of fluid escape in geophysical images. A critical concern is how to account for features that are detrimental to subsurface storage containment and are at scales below seismic resolution. This multidisciplinary project aims to address the challenge by collecting surface and subsurface datasets at mesoscopic scales that, through viable upscaling, will be implemented in seismic investigations and reservoir-seal models. Moreover, the project builds upon previous studies detailing the complex development of the Jurassic sedimentary basin in question (Zuchuat et al. 2018; 2019; in press) but is also relevant for the Horda Platform region (Aurora and Smeaheia) or other prospective North Sea CO2 storage sites. Overall, this next research phase specifically focuses on the detailed, post-depositional history of the targeted interval in Utah, addressing one fundamental question: what are the thresholds for detecting CO2 seeps in the subsurface? This encompasses more targeted questions: • What is the detailed geological footprint of CO2 flow along strata, faults, and fractures? • How did the CO2 flow migrate through a heterogeneous and transitional, faulted reservoir-seal complex? • Can seepage from the storage compartment be identified by seismic imaging? • Can detailed geological datasets and related geophysical models verify the existence of – and facilitate quantification of CO2 volumes (saturation) required to create offshore geophysical chimneys, and thereby improve integrity assessment of prospective North Sea CO2 reservoirs? Zuchuat, V., Sleveland, A. R., Sprinkel, D. A., Rimkus, A., Braathen, A., & Midtkandal, I. (2018). New Insights on the Impact of Tidal Currents on a Low-gradient, Semi-enclosed, Epicontinental Basin—the Curtis Formation, East-central Utah, USA. Geology of the Intermountain West, 5, 131-165. Zuchuat, V., Sleveland, A.R.N., Pettigrew, R.P, Dodd, T.J.H., Clarke, S.M., Braathen, A., & Midtkandal, I. (2019). Overprinted Allocyclic Processes by Tidal Resonance in an Epicontinental Basin: the Upper Jurassic Curtis Formation, East-Central Utah, USA. The Depositional Record, 5(2), 272-305. Zuchuat, V., Midtkandal, I., Poyatos-Moré, M., Da Costa, S., Brooks, H.L., Halvorsen, K., Cote, N., Sundal, A., & Braathen, A. (in press.). Composite and Diachronous Stratigraphic Surfaces in Low-Gradient, Transitional Settings: the J-3 “Unconformity” and the Curtis Formation, East-Central Utah, U.S.A. Accepted in The Journal of Sedimentary Research.

• Sundal, Anja (2019). Geologisk lagring av CO2 på norsk sokkel.
• Sundal, Anja (2019). Geologisk CO2-lagring – trygt og godt for alltid? Vis sammendrag

  Program: https://www.uio.no/om/samarbeid/skole/fagped-dag/program/

• Sundal, Anja (2019). Hydrogeology of the Svelvik CO2-Field lab. . Vis sammendrag

  Program: https://www.sintef.no/projectweb/svelvik-co2-field-lab/nyheter/svelvik-opening/

• Sundal, Anja (2019). Safe storage of CO2.
• Sundal, Anja & Ruden, Fridtjof (2019). CO2-lagring i grunnen – hydrogeologisk feltlaboratorium på Svelvik. Vis sammendrag

  Event: https://facebook.com/events/2159455514177753/?ti=cl

• Weber, Ulrich Wolfgang; Kipfer, Rolf; Brennwald, Matthias S.; Ringrose, Philip & Sundal, Anja (2019). Noble Gases as Monitoring Tracers: Sampling Campaigns at Capture Sites Technology Center Mongstad and Melkøya.
• Sundal, Anja; Miri, Rohaldin; Andersen, Odd; Hellevang, Helge; Gregersen, Ulrik & Olivarius, Mette [Vis alle 14 forfattere av denne artikkelen] (2019). Optimized CO2 storage in sloping aquifers: Estimation of physical and chemical immobilization potential and retardation along migration path in open storage solutions .
• Sundal, Anja; French, Helen Kristine & Aagaard, Per (2019). Hydrogeology for students and society: outreach integration in education .
• Sundal, Anja; Tuttle, Kevin J.; Aagaard, Per; Fikse, Andrea Nymoen; Moe, K.G. & Øvstedal, Jarl (2019). Managing and monitoring dynamic ravinement processes.
• Sena, Clara; Sundal, Anja; Uglum, Maria C.; Kristiansen, Ingrid E. & Kvitsjøen, Julia (2019). Hydrogeological tools in urban runoff management – case study from Torshovdalen, Oslo.
• Aagaard, Per; Sena, Clara; Sundal, Anja & French, Helen Kristine (2019). In situ removal of iron and manganese, the Vyredox treatment system at Elverum .
• Andersen, Odd & Sundal, Anja (2019). Using 2D seismic line data to estimate impact of caprock morphology on CO2 migration in the Gassum formation. Fulltekst i vitenarkiv Vis sammendrag

  The Gassum Formation on the Norwegian Continental Shelf serves as the principal case study for the CO2-Upslope project. The top surface of this formation is gently sloping, and characterized by a number of macro-scale structural traps, a few large faults, a large number of small faults, and small-scale depth variations that can be inferred and extrapolated from the seismic data. In the study presented in this paper, we estimate the amount of macro- and sub-scale trapping potential of the formation based on interpreted 2D seismic lines and identified faults. The seismic lines provide the depth of the caprock at each point along straight lateral paths. In the available data, a few dozen such lines cross the study area at various angles. A number of medium and large faults could be explicitly identified and mapped, as they correlate between several of these lines. In addition, hundreds of small-scale faults are only visible as discontinuities along individual lines. The extent and shape of these small faults between the seismic sections cannot be explicitly known from the data. In order to investigate trapping potential, we start out by constructing multiple realizations of the top surface, constructed to be faithful to both large-scale topography and small-scale statistical properties. We use a tensor spline surface approximation to represent the surface trend, with added stochastic small-scale variations consistent with the statistical properties of the line data. Moreover, we include a distribution small-scale faults that are only visible as discontinuities in the seismic lines by adding assumptions on their general orientations and lengths. At the timescales associated with long-term CO2 plume migration, it can generally be assumed that vertical equilibrium has been reached and that the CO2 slowly flows as a thin wedge right under the top surface, driven by gravity forces. Based on this assumption, we apply spill-point analysis and upscaling techniques on our sets of top surface realizations to explore the possible range of values for total structural trapping and plume retardation potential, and how they depend on the assumptions made. We also study the impact of the placement of the injection site, and how much of the total structural storage potential can be actually realized based on the position of the site and the injection strategy.

• Sundal, Anja (2019). GEO-onsdag: Geologisk CO2-lagring – trygt og godt for alltid? . Vis sammendrag

  Foredraget er publisert på nett: https://www.youtube.com/watch?v=artSoVqp-F0

• Sundal, Anja (2019). Application of noble gas signatures in monitoring schemes for CO2 storage offshore Norway. Vis sammendrag

  Short (1 slide) pitch about the ICO2P project

• Sundal, Anja (2019). Cost-effective monitoring by application of noble gas signatures.
• Weber, Ulrich Wolfgang & Sundal, Anja (2019). Application of noble gas signatures in monitoring schemes for offshore CO2 storage (ICO2P).
• Weber, Ulrich Wolfgang; Sundal, Anja; Brennwald, M.S. & Kipfer, Rolf (2019). Temporal Variation in Noble Gas Signatures of Captured CO2.
• Gregersen, Ulrik; Baig, Irfan; Sundal, Anja; Nielsen, Lars Henrik; Olivarius, Mette & Weibel, Rikke (2018). Seismic interpretation of a slopping offshore potential CO2 aquifer; the Gassum Formation in Skagerrak between Norway and Denmark.
• daCosta, Sigrid Østmo; Bromander, Nikoline; Zuchuat, Valentin; Braathen, Alvar; Sundal, Anja & Midtkandal, Ivar (2018). Topographic Development as a result of regional incision, faulting, and deposition at the onset of relative sea-level rise; The upper Entrada Sandstone and the lower Curtis Formation, Utah, USA.
• Skurtveit, Elin; Sundal, Anja; Soldal, Magnus; Sauvin, Guillaume & Bjørnarå, Tore Ingvald (2018). CO2 flow, alteration and geomechanical response in confining units – An experimental approach. Fulltekst i vitenarkiv
• Midtkandal, Ivar; Sundal, Anja; Braathen, Alvar; Petrie, Elizabeth; Evans, James R. & Zuchuat, Valentin [Vis alle 10 forfattere av denne artikkelen] (2018). Project summary: CO2 seal bypass - a multidisciplinary approach to CO2 migration and storage.
• Sundal, Anja; Weber, Ulrich Wolfgang; Brennwald, Matthias S.; Ringrose, Philip; enaasen flø, nina & Johnsen, Kim [Vis alle 9 forfattere av denne artikkelen] (2018). Monitoring real time, in-line variations of noble gas concentrations during CO2 capture operations by means of a portable mass spectrometer .
• Weber, Ulrich Wolfgang; Sundal, Anja; Brennwald, M.S.; Ringrose, Philip; Aagaard, P. & Kipfer, Rolf (2018). CO2 Capture Processes Monitored with Noble Gas Measurements. Vis sammendrag

  In the ICO2P project [1] a monitoring scheme for carbon capture and storage is developed with the aim to use noble gases as signatures for capture products. One approach to capture CO2 is amine-based temperature swing absorption. During such processes there is a potential for depletion of radiogenic noble gases from the fossil source, due to the addition of a gas phase void of radiogenic noble gases. The influence on the noble gas fingerprints of such techniques is investigated by single, analysed samples with full isotope resolution. This is combined with in-line, continuous noble gas measurements with a portable mass spectrometer [2]. This is a new approach that will provide knowledge of the uniqueness and temporal variations of noble gas fingerprints in the product stream from CO2 capture operations. The feasibility of such an on-site measurement system was successfully tested at a CO2 capture testing facility in Norway (TCM). Matching of the data with the reservoir source combusted at that time, forms the basis for setting up geochemical analytical schemes in mixing scenarios. Monitoring data from CO2 product streams are key in designing leakage detection schemes for future storage sites.

• Grimstad, Alv-Arne; Sundal, Anja; Ringstad, Cathrine & Hagby, Klaus Falk (2018). Modelling medium-depth CO2 injection at the Svelvik CO2 field laboratory in Norway.
• Uglum, Maria C.; Sundal, Anja; Sena, Clara & Kvitsjøen, Julia (2018). CONSIDERING GROUNDWATER RECHARGE AND FLOW IN URBAN DEVELOPMENT PLANNING – A CASE STUDY FROM TORSHOVDALEN, OSLO .
• Kristiansen, Ingrid E.; Uglum, Maria C.; Sena, Clara; Sundal, Anja & Kvitsjøen, Julia (2018). ASSESSMENT OF THE URBAN RUNOFF AND GROUNDWATER QUALITY IN THE RECREATIONAL AREA OF TORSHOVDALEN (OSLO, NORWAY).
• Gregersen, Ulrik; Baig, Irfan; Sundal, Anja; Nielsen, Lars-Henrik; Olivarius, Mette & Weibel, Rikke (2018). Seismic interpretation of a potential CO2 reservoir; the Gassum Formation, a sloping aquifer in Skagerrak between Norway and Denmark.
• Olivarius, Mette; Sundal, Anja; Gregersen, Ulrik; Thomsen, T.B.; Weibel, Rikke & Nielsen, Lars-Henrik (2018). Using petrography and provenance data to assess the CO2 trapping potential in sloping sandstones in the Skagerrak Strait. EAGE extended abstracts. doi: 10.3997/2214-4609.201801148. Vis sammendrag

  80th EAGE Conference and Exhibition 2018 CO2 Capture, Storage and Utilization http://www.earthdoc.org/publication/publicationdetails/?publication=92535

• Bromander, Nikoline; da Costa, Sigrid; Skurtveit, Elin; Evans, Jim; Midtkandal, Ivar & Zuchuat, Valentin [Vis alle 8 forfattere av denne artikkelen] (2018). Regional evaluation of structural collapse in sandstone reservoirs and impact on reservoir quality: a case study from the Entrada Sandstone, Utah, USA.
• Sacco, Tatiana; Sundal, Anja & Hellevang, Helge (2018). Mass estimation of CO2 trapping potential in the Smeaheia reservoir.
• Sundal, Anja; Hellevang, Helge; Olivarius, Mette; Miri, Rohaldin; Nielsen, Lars-Henrik & Gregersen, Ulrik [Vis alle 10 forfattere av denne artikkelen] (2018). Geological Constraints on the immobilization potential for CO2 in the Gassum Fm. (Skagerrak, Norway).
• Zuchuat, Valentin; Midtkandal, Ivar; Miquel, Poyatos-More; Da Costa, Sigrid; Halvorsen, Kristine Årland & Sundal, Anja [Vis alle 8 forfattere av denne artikkelen] (2018). Unconformities matter: The spatial and temporal information contained in the J-3 Unconformity and the Curtis Formation, east-central Utah, USA.
• Gasda, Sarah; Elenius, Maria; Skurtveit, Elin; Sundal, Anja; Yarushina, Viktoriya M. & Baig, Irfan [Vis alle 13 forfattere av denne artikkelen] (2018). Skade Case Study.
• Kaufmann, Roland; Gasda, Sarah Eileen; Elenius, Maria; Skurtveit, Elin; Choi, Jung Chan & Sundal, Anja [Vis alle 9 forfattere av denne artikkelen] (2018). Arbeidsflyt for trykk-basert kapasitets-anslag: En eksempelstudie på Smeaheia.
• Kaufmann, Roland; Gasda, Sarah Eileen; Elenius, Maria; Skurtveit, Elin; Choi, Jung Chan & Braathen, Alvar [Vis alle 9 forfattere av denne artikkelen] (2018). Large-scale CO2-injection in Smeaheia.
• Sundal, Anja; Kipfer, Rolf & Brennwald, Matthias S. (2017). Apparent Heating of Groundwater in the Gardermoen Aquifer, Norway .
• Sundal, Anja (2017). KARBONLAGRING: Undergrunn + CO2 = trygt. Vis sammendrag

  Bli inspirert av åtte lynpresentasjoner om FNs bærekraftmål #7: Ren energi til alle. https://www.studentevent.no/events/84583 Velkommen til en lærerik og sosial kveld på Kulturhuset. Ta gjerne med en venn eller kollega – arrangementet er åpent og gratis for alle. Øl får du kjøpt i baren. NYHET! Tekna X er vår nye populærvitenskapelige formidlingsserie av spennende temaer som opptar unge. Vi gjør det ukjente kjent i høyt tempo med en sosial ramme. Hvert innlegg varer maks 8 minutter som gir deg mye ny kunnskap på kort tid – også ting du ikke visste du lurte på.

• Zuchuat, Valentin; Midtkandal, Ivar; Da Costa, Sigrid; Sundal, Anja & Braathen, Alvar (2017). Schizophrenia in sedimentology: The J-3 Unconformity and the Curtis Formation, Central-Eastern Utah, USA. Vis sammendrag

  The tide-dominated, Upper Jurassic Curtis Formation crops out in Eastern-Central Utah, overlying the continental to marginal marine Entrada Sandstone. The contact between the two sedimentary formations is formally identified as the J-3 Unconformity, which can be traced over significant distances. It has since been regarded as a “simple” subaerial unconformity, followed by a third order transgression within an enclosed basin and the resulting deposition of the tide-influenced Curtis Formation. However, careful inspection of the different facies and their sub-regional correlation clearly shows that the essence of the J-3 Unconformity is not merely characterised by a long-lasting phase of subaerial exposure. It instead displays evidence of an intricate poly-erosional history, happening during short-lived syn-depositional transgressive and regressive periods. The initial bounding surface was locally altered by processes associated with development of the Curtis Formation, and the nature of their impact is strongly process-dependent. Pre-Curtis erosional processes mainly involved aeolian deflation and fluvial incision, creating a basinwide gentle relief. Syn-Curtis erosional mechanisms were controlled by the distribution and magnitude of tidal forces within the basin, resulting in a steeper and more localised relief in comparison with pre-Curtis widespread denudation. Furthermore, sedimentary processes alone can’t explain the present-day relief observed with the J-3 Unconformity. Indeed, tectonic played, at various scale, a key role in the funnelling of the various erosional forces and the distribution of the depocentres, with (i) m-scale grabens and horsts structures, and (ii) hydroplastic sand remobilisation, both observed within the uppermost strata of the Entrada Sandstone, as well as (iii) syn-Curtis sub-regional tectonic uplift. This study shows that reducing an unconformity to a single process is insufficient. Instead, careful mapping and understanding of such a schizophrenic surface can provide a non-negligible amount of information regarding the dynamic of a basin and its subsequent infill.

• Sundal, Anja (2017). KARBONLAGRING: CO2 + Undergrunn = Sant.
• Elenius, Maria; Hellevang, Helge; Skurtveit, Elin; Yurushina, Viktoriya; Baig, Irfan & Sundal, Anja [Vis alle 12 forfattere av denne artikkelen] (2017). Workflow for evaluation of large-scale CO2 storage feasibility: Skade.
• Elenius, Maria; Hellevang, Helge; Skurtveit, Elin; Yurushina, Viktoriya; Baig, Irfan & Sundal, Anja [Vis alle 12 forfattere av denne artikkelen] (2017). Storage feasibility in North Sea aquifers.
• Elenius, Maria; Hellevang, Helge; Skurtveit, Elin; Yurushina, Viktoriya; Baig, Irfan & Sundal, Anja [Vis alle 12 forfattere av denne artikkelen] (2017). Workflow for assessment of storage based on sparse data: Skade.
• Sundal, Anja; Brennwald, Matthias S.; Per, Aagaard; Philip, Ringrose & Rolf, Kipfer (2017). APPLICATION OF NOBLE GAS SIGNATURES IN MONITORING SCHEMES FOR CO2 STORAGE.
• Harris, Sharon; Anell, Ingrid Margareta; Sundal, Anja; Braathen, Alvar & Faleide, J I (2019). The tectono-sedimentary development of Smeaheia on the Horda Platform with a focus on the Cretaceous, and implications for CO2 storage. 7Letras.
• Kolnes, Jens; Anell, i; Mulrooney, Mark Joseph; Veggeland, Frode & Faleide, J I (2019). Reconstruction of the subsidence and uplift history of a proposed CO2 storage site in the northern North Sea. 7Letras.
• Bromander, Nikoline; Sundal, Anja; Skurtveit, Elin; Midtkandal, Ivar & Braathen, Alvar (2018). Facies-controlled reservoir quality and preferential deformation in sandstone reservoirs; a case study from the Entrada Sandstone, Utah, USA. 7Letras.
• Bromander, Nikoline; Sundal, Anja; Midtkandal, Ivar & Zuchuat, Valentin (2018). Facies-controlled reservoir quality and preferential deformation in sandstone reservoirs; a case study from the Entrada Sandstone, Utah, USA. Universitetet i Oslo.
• Elenius, Maria; Sundal, Anja; Gasda, Sarah; Aavatsmark, Ivar; Hellevang, Helge & Hermanrud, Christian [Vis alle 8 forfattere av denne artikkelen] (2018). Storage Capability [FME SUCCESS Synthesis report Volume 1]. SUCCESS [Christian Michelsen Research AS].
• Sundal, Anja; Hellevang, Helge & Sacco, Tatiana (2018). CO2 trapping in the Smeaheia reservoir - time mass estimation using geochemical models. Universitetet i Oslo.

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