Now showing items 77-96 of 206

    • Flow behavior of thermo-thickening associative polymers in porous media: effects of associative content, salinity, time, velocity, and temperature 

      Åsen, Siv Marie; Stavland, Arne; Strand, Daniel (Journal article; Peer reviewed, 2022)
      Above a critical temperature, thermo-thickening associative polymers (TAPs) have a superior ability to decrease the mobility of the water phase, compared to traditional polymers for enhanced oil recovery. The ability to ...
    • Fluid Migration Characterization of Full-scale Annulus Cement Sections Using Pressure-Pulse-Decay Measurements 

      Skadsem, Hans Joakim (Peer reviewed; Journal article, 2021)
      Fluid migration behind casings is a well integrity problem that can result in sustained casing pressure, undetected leaks to the environment, and potentially very challenging remediation attempts. Understanding the geometric ...
    • Forecasting Piston Rod Seal Failure Based on Acoustic Emission Features in ARIMA Model 

      Pedersen, Jørgen Fone; Schlanbusch, Rune; Shanbhag, Vignesh Vishnudas (Peer reviewed; Journal article, 2022)
      Fluid leakage due to piston rod seal failure in hydraulic cylinders results in unscheduled maintenance, machine downtime and loss of productivity. Therefore, it is vital to understand the piston rod seal failure at initial ...
    • Formulating the history matching problem with consistent error statistics 

      Evensen, Geir (Peer reviewed; Journal article, 2021)
      It is common to formulate the history-matching problem using Bayes’ theorem. From Bayes’, the conditional probability density function (pdf) of the uncertain model parameters is proportional to the prior pdf of the model ...
    • Framework for effective robust design of building energy systems: Bridging the gap between predicted and actual energy use 

      Kocbach, Jan Martin; Folgerø, Kjetil; Skålvik, Astrid Marie; Olsen Wulff, Maria; Kjellberg, Bianca Karolina; Harsem, Trond Thorgeir (Peer reviewed; Journal article, 2022)
      Practitioners working on building performance simulations do seldom apply uncertainty and sensitivity analysis using state-of-the-art global methods in their daily workflow. With stricter building regulations imposed year ...
    • From outcrop scanlines to discrete fracture networks, an integrative workflow 

      Lepillier, Baptiste; Bruna, Pierre-Olivier; Bruhn, David; Bastesen, Eivind; Daniilidis, Alexandros; Garcia, Óscar; Torabi, Anita; Wheeler, Walter H (Journal article; Peer reviewed, 2020)
      Understanding fractures and fracture networks is essential for the investigation and use of subsurface reservoirs. The aim is to predict the fractures and the fracture network when there is no direct access to subsurface ...
    • Fuzzy Gain-Scheduling PID for UAV Position and Altitude Controllers 

      Melo, Aurelio G.; Andrade, Fabio Augusto de Alcantara; Guedes, Ihannah P.; Carvalho, Guilherme F.; Zachi, Alessandro R. L.; Pinto, Milena F. (Peer reviewed; Journal article, 2022)
      Unmanned aerial vehicle (UAV) applications have evolved to a wide range of fields in the last decade. One of the main challenges in autonomous tasks is the UAV stability during maneuvers. Thus, attitude and position control ...
    • Geocellular rendering of cave surveys in paleokarst reservoir models 

      Lønøy, Bjarte; Tveranger, Jan; Pennos, Christos; Whitaker, Fiona; Lauritzen, Stein-Erik (Peer reviewed; Journal article, 2020)
      Infilled and collapsed cave systems are an important component of many paleokarst reservoirs. Incorporating these features into industrial reservoir models commonly relies on geostatistical modelling methods that often ...
    • Great expectations: Migrant parents and parent-school cooperation in Norway 

      Bendixsen, Synnøve Kristine Nepstad; Danielsen, Hilde (Peer reviewed; Journal article, 2020)
      One long-standing characteristic of schools in Norway is inclusive education as a primary goal. The last years, the Norwegian government has emphasised increased parent-school cooperation as a way to limit risks, i.e. of ...
    • Health Indicator for Low-speed Axial Bearings using Variational Autoencoders 

      Hemmer, Martin; Klausen, Andreas; Huynh, Khang; Robbersmyr, Kjell Gunnar; Waag, Tor Inge (Peer reviewed; Journal article, 2020)
      This paper proposes a method for calculating a health indicator (HI) for low-speed axial rolling element bearing (REB) health assessment by utilizing the latent representation obtained by variational inference using ...
    • Hierarchical Representation Learning in Graph Neural Networks with Node Decimation Pooling 

      Bianchi, Filippo Maria; Grattarola, Daniele; Livi, Lorenzo; Alippi, Cesare (Peer reviewed; Journal article, 2020)
      Abstract—In graph neural networks (GNNs), pooling operators compute local summaries of input graphs to capture their global properties, and they are fundamental for building deep GNNs that learn hierarchical representations. ...
    • Homotopy scattering series for seismic forward modelling with variable density and velocity 

      Xiang, Kui; Eikrem, Kjersti Solberg; Jakobsen, Morten; Nævdal, Geir (Peer reviewed; Journal article, 2021)
      We have derived a convergent scattering series solution for the frequency-domain wave equation in acoustic media with variable density and velocity. The convergent scattering series solution is based on the homotopy analysis ...
    • Hybrid Iterative Ensemble Smoother for History Matching of Hierarchical Models 

      Oliver, Dean (Peer reviewed; Journal article, 2022)
      The choice of a prior model can have a large impact on the ability to assimilate data. In standard applications of ensemble-based data assimilation, all realizations in the initial ensemble are generated from the same ...
    • HYDROGEN POWERED VESSELS AT SEA:FUEL CELL & BATTERY UPSCALING 

      Helleland, Christer; Iversen, Fionn; Halstensen, Svein Olav (Chapter, 2022)
      There is today a strong effort in developing fuel cell / battery systems for ship propulsion to achieve zero-emission maritime transport, in accordance with UN sustainability goals and the Fit For 55 plan to achieve the ...
    • Imbibition with solidification in alumina feeding 

      Kovacs, Atitla; Breward, Chris; Oliver, James; Münch, Andreas; Halvorsen, Svenn Anton; Nordgård-Hansen, Ellen; Manger, Eirik (Lecture, 2019)
    • Impact of time-dependent wettability alteration on the dynamics of capillary pressure 

      Kassa, Abay; Gasda, Sarah; Kumar, Kundan; Radu, Florin Adrian (Peer reviewed; Journal article, 2020)
      Wettability is a pore-scale property that has an important impact on capillarity, residual trapping, and hysteresis in porous media systems. In many applications, the wettability of the rock surface is assumed to be constant ...
    • Implicit linearization scheme for nonstandard two-phase flow in porous media 

      Kassa, Abay; Kumar, Kundan; Gasda, Sarah; Radu, Florin Adrian (Peer reviewed; Journal article, 2020)
      In this article, we consider a nonlocal (in time) two‐phase flow model. The nonlocality is introduced through the wettability alteration induced dynamic capillary pressure function. We present a monotone fixed‐point iterative ...
    • Improving hydropower inflow forecasts by assimilating snow data 

      Magnusson, Jan; Nævdal, Geir; Matt, Felix; Burkhart, John F; Winstral, Adam (Journal article; Peer reviewed, 2020)
      The study describes the depositional development and sediment partitioning in a prograding paralic Triassic succession. The deposits are associated with the advance of large prism‐scale clinoforms across a shallower platform ...
    • Improving Sequential Decisions – Efficiently Accounting for Future Learning 

      Wang, Lingya; Oliver, Dean (Peer reviewed; Journal article, 2021)
      In sequential field development planning, past decisions not only directly affect the maximum achievable expected NPV but also influence the future information that can be used to reduce geological uncertainty. To act ...
    • Integrated Stress Field Estimation and Implications for Enhanced Geothermal System Development in Acoculco, Mexico 

      Kruszewski, Michal; Hofmann, Hannes; Alvarez, Fidel Gomez; Bianco, Caterina; Haro, Adrian Jimenez; Garduño, Victor Hugo; Liotta, Domenico; Trumpy, Eugenio; Brogi, Andrea; Wheeler, Walter H; Bastesen, Eivind; Parisio, Francesco; Saenger, Erik H. (Journal article; Peer reviewed, 2021)
      Data gathered from two geothermal exploration wells in the Acoculco caldera, within the Trans-Mexican Volcanic Belt, indicated that temperature is high enough for economic utilization, but permeability is insufficient. ...