Institutt for geovitenskap og petroleum
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Wavefield reconstruction for velocity–stress elastodynamic full-waveform inversion
(Peer reviewed; Journal article, 2020)Gradient computations in full-waveform inversion (FWI) require calculating zero-lag cross-correlations of two wavefields propagating in opposite temporal directions. Lossless media permit accurate and efficient reconstruction ... -
Compositional Features and Swelling Potential of Two Weak Rock Types Affecting Their Slake Durability
(Journal article, 2021)Weak and weathered rocks are well known for their sensitivity to changes in moisture content. Degrading behavior is common in weak rocks with moisture-sensitive mineral components and present numerous stability problems. ... -
Investigation of copper recovery from a new copper deposit (Nussir) in northern Norway
(Peer reviewed; Journal article, 2019)Norway has seen an upsurge of interest in exploiting its mineral deposits during the last decade. One of the major areas of interest is a huge copper deposit, operated by Nussir ASA located in the Repparfjord tectonic ... -
Operation of Norwegian Hydropower Plants and Its Effect on Block Fall Events in Unlined Pressure Tunnels and Shafts
(Peer reviewed; Journal article, 2021)The main objective of this study is to investigate the effect of hydropower plant operation on the long-term stability of unlined pressure tunnels of hydropower plants in Norway. The authors analyzed the past production ... -
Evaluation on the Efect of Pressure Transients on Rock Joints in Unlined Hydropower Tunnels Using Numerical Simulation
(Peer reviewed; Journal article, 2021)Frequent pressure transients are identified as the cause of block failures in many unlined hydropower tunnels. The primary design objective of such tunnels is to prevent hydraulic jacking at design static pressure and mass ... -
Green foam-based methods of mineral and ion separation
(Chapter, 2020)We discuss an important gap in the literature on progress toward the development of green (microbial-derived) reagents in conventional (froth flotation) and emerging (foam flotation)separation methods. For comparison, we ... -
Application of glucolipid bola-amphiboles biosurfactant in mineral processing
(Chapter, 2021)Yeast-derived amphiboles have attracted considerable attention for their applications in various industrial sectors. However, only a few studies on this class of surfactant have been reported to be relevant to mineral ... -
Organosilane and lignosulfonate as innovative stabilization techniques for crushed rocks used in road unbound layers
(Peer reviewed; Journal article, 2020)The tunnelling operations connected to the construction of the new Norwegian E39 highway generate a considerable amount of blasted rocks. The local use of these rocks as construction materials in the unbound layers of the ... -
An overview of calcite recovery by flotation
(Peer reviewed; Journal article, 2020)In general, precipitated calcium carbonate (PCC) is used as amineral filler in paper industries; while natural calcite (CaCO3) ore is also suitable for industrial use if it is a finely ground high-grade material. Naturally, ... -
Geometrically derived efficiency of slow immiscible displacement in porous media
(Peer reviewed; Journal article, 2020)The efficiency of a displacement is the fraction of applied work over the change in free energy. This displacement efficiency is essential for linking wettability to applied work during displacement processes. We quantify ... -
Liquiñe‑Ofqui’s fast slipping intra‑volcanic arc crustal faulting above the subducted Chile Ridge
(Peer reviewed; Journal article, 2021)The southernmost portion of the Liquiñe-Ofqui fault zone (LOFZ) lies within the proposed slab window which formed due to oblique subduction of the Chile Ridge in Patagonia. Mapping of paleo-surface ruptures, offsets, and ... -
Contact Angles in Two-Phase Flow Images
(Peer reviewed; Journal article, 2020)In this work, we calculate contact angles in X-ray tomography images of two-phase flow in order to investigate the wettability. Triangulated surfaces, generated using the images, are smoothed to calculate the contact angles. ... -
Hysteresis of Natural Magnetite Ensembles: Micromagnetics of Silicate‐Hosted Magnetite Inclusions Based on Focused‐Ion‐Beam Nanotomography
(Peer reviewed; Journal article, 2020)Three‐dimensional geometries of silicate‐hosted magnetic inclusions from the Harcus intrusion, South Australia have been determined using focused‐ion‐beam nanotomography (FIB‐nt). By developing an effective workflow, the ... -
Application of nanoparticles for oil recovery.
(Peer reviewed; Journal article, 2021)Due to their large surface-area-to-volume ratio and enhanced chemical reactivity, nanoparticles have attracted interest among researchers in the upstream petroleum industry for oil recovery applications. Nanoparticles have ... -
Dither signals optimization in constrained multi-agent extremum seeking control
(Peer reviewed; Journal article, 2021)In this paper we consider the problem of optimization of a multi-agent system with constraints through perturbations-based extremum seeking control. We demonstrate that for such systems, effects of dither signals applied ... -
Separating geometry- from stress-induced remanent magnetization in magnetite with ilmenite lamellae from the Stardalur basalts, Iceland
(Peer reviewed; Journal article, 2020)Realistic geometries of magnetite grains from the Stardalur volcano, Iceland, were obtained by Focused Ion Beam Scanning Electron Microscopy nanotomography. These magnetite grains are subdivided by oxidation‐exsolution ... -
Mapping and modelling mineral sources of natural remanent magnetization from the Russell Belt microcline-sillimanite gneiss, Northwest Adirondack Mountains, USA
(Peer reviewed; Journal article, 2021)Distinct crustal remanent magnetic anomalies are a strong indicator of rocks with stable natural remanent magnetization (NRM) carriers. The latter are able to store information on the history of a rock over long geological ... -
An improved model for predicting liquid loading onset in inclined pipes with non-uniform liquid wall films
(Peer reviewed; Journal article, 2021)Liquid loading is a phenomenon in which liquid accumulates in the wellbore of mature gas wells, causing a significant reduction in production and sometimes permanent well abandonment. This paper introduces a new model for ... -
Fluid Flow and Leakage Assessment Through an Unlined/Shotcrete Lined Pressure Tunnel: A Case from Nepal Himalaya
(Peer reviewed; Journal article, 2021)The use of unlined/shotcrete lined pressure tunnels and shafts are cost-efective solutions for a hydropower project and are being implemented worldwide. To implement this concept, the ground conditions at the area of concern ... -
Rock Stress Measurements for Unlined Pressure Tunnels: A True Triaxial Laboratory Experiment to Investigate the Ability of a Simplified Hydraulic Jacking Test to Assess Fracture Normal Stress
(Peer reviewed; Journal article, 2021)To avoid hydraulic failure of unlined pressure tunnels, knowledge of minimum principal stress is needed. Such knowledge is only obtainable from in situ measurements, which are often time-consuming and relatively costly, ...
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