CO2 Foam Dynamics During CO2 Enhanced Oil Recovery and CO2 Storage

Den stadig voksende befolkningen, økende velstand og økonomisk vekst fører til økende etterspørsel etter energi. Forbrenning av fossile brensler står for 80% av den globale energi produksjonen, noe som gjør det til en verdifull energikilde. Det forventes at verdensbefolkningen skal øke med to milliarder i løpet av de neste 30 årene, og energietterspørselen forventes å øke med 1% per år frem til 2030. Denne raske veksten og økende etterspørselen indikerer at fossile brensler forblir viktige for samfunnet i de kommende årene. Som en konsekvens trues menneskeheten av menneskeskapte klimaendringer, der energiproduksjonen står for tre fjerdedeler av de globale utslippene av klimagasser. En rask endring i energisystemet er nødvendig for å forsyne verden med tilstrekkelig energi og redusere klimaendringer. Karbonfangst og -lagring (carbon capture and storage, CCS) er et viktig tiltak for å begrense global oppvarming og oppnå klimamålene erklært i Parisavtalen. Denne teknologien innebærer å fange CO2 fra industrielle og energirelaterte kilder og permanent lagre CO2 isolert fra atmosfæren. Storskala implementering av CCS står for øyeblikket over økonomiske utfordringer. Bruk av CO2 som et produkt kan gi økonomisk støtte for storskala CCS. Bruk av CO2 for økt olje utvinning (enhanced oil recovery, EOR) er en veletablert og lovende teknologi som bidrar til økt profitt og samtidig økt oljeproduksjon. CO2 EOR har blitt utført i over 50 år og er en velkjent teknologi som bidrar til den pågående energiomstillingen. Imidlertid er effektiviteten til denne teknologien begrenset av utfordringer knyttet til høy CO2 mobilitet og reservoarheterogenitet. CO2 skum er en teknologisk løsning hvor CO2 og en surfaktantløsning blandes for å redusere mobiliteten til CO2 og forbedre fortrengningen i EOR og CO2 lagring prosesser. Tidligere CO2 skum testpiloter på feltskala har blitt rapportert som teknisk vellykket med bevis på skumdannelse, forbedret fortrengningsevne og økt oljeutvinning. Andre tester derimot ble ansett som mislykket på grunn av injeksjonsproblemer og dårlig skumpropagering i reservoaret. Derfor er det et behov for en grundigere forståelse av skumdynamikk, styrke, stabilitet og størrelsesavhengige fortrengningsmekanismer for å videreutvikle teknologien. Denne avhandlingen er basert på seks vitenskapelige artikler som til sammen utgjør en flerskala studie av CO2 skum for mobilitetskontroll for EOR og CO2 lagring. Studien gir innsikt i grunnleggende konsepter innen skum, undersøker innflytelse av ulike faktorer, som tilstedeværelse av olje og konsentrasjon av surfaktantløsning, på CO2 skum oppførsel og evaluerer effektiviteten av CO2 skum for å forbedre oljeutvinning og øke CO2 lagringskapasitet.The ever-growing population, increasing prosperity, and economic growth leads to increased energy demand. The combustion of fossil fuels accounts for 80% of the global energy mix, making it a valuable energy source. The global population is expected to increase by two billion in the next 30 years, and energy demand is predicted to increase by 1% a year to 2030. This rapid growth and increasing demand indicate that fossil fuels will remain important for society in the coming years. Consequently, humanity is threatened by human-induced climate change, with energy production accounting for three-quarters of global greenhouse gas emissions. A rapid change in the energy system is needed to supply the world with sufficient energy and mitigate climate change. Carbon capture and storage (CCS) is an important measure to limit global warming and achieve the climate goals stated in the Paris Agreement. The technology includes capturing CO2 from industrial and energy-related sources and permanently storing CO2 isolated from the atmosphere. Large-scale implementation of CCS currently faces economic barriers. Utilization of CO2 as a commodity can provide a financial incentive for large-scale CCS. Using CO2 for enhanced oil recovery (EOR) is a well-established and promising technology that provides economic revenue while increasing oil production. CO2 EOR has been performed for over 50 years and is a proven technology contributing to the ongoing energy transition. However, the effectiveness of this technology is limited by challenges associated with high CO2 mobility and reservoir heterogeneity. Foaming CO2 is a technological solution where CO2 and a foaming solution are mixed to reduce CO2 mobility and improve sweep efficiency in EOR and CO2 storage processes. Previous foam field tests have been reported as technical successes with evidence of foam generation, improved sweep efficiency, and enhanced oil recovery. Others were deemed unsuccessful due to injectivity problems and limited foam propagation in the reservoir. Thus, a more thorough understanding of foam dynamics, strength, stability, and size-dependent displacement mechanisms is needed to advance the technology. This thesis is based upon six scientific papers, which together constitute a multi-scale study of CO2 foam for mobility control for EOR and associated CO2 storage. The study provides insight into the fundamental concepts of foam, investigates the influence of various factors, such as the presence of oil and foaming solution concentration, on CO2 foam behavior, and evaluates the effectiveness of CO2 foam in improving oil recovery and increasing CO2 storage capacity.Doktorgradsavhandlin

Design and Synthesis of xCT Inhibitor Candidates

Masteroppgave i kjemiKJEM399MAMN-KJE

Artificial gas supersaturated water from small hydropower plants: methods to detect air entrainment at intakes

Hydropower plants with submerged intake and Francis turbine can release artificial Total Dissolved Gas (TDG) supersaturated water from the plants outlet, if air is drawn into the pressure pipe at intake and dissolved in water at high pressure. Air entrainment at intake can be initiated by debris covered trash rack [1]. Fish exposed to TDG supersaturated water can develop Gas Bubble Disease (GBD), which is harmful and can result in fish death. A common used small hydropower plant design consist of submerged intake, intake air vent, pressure pipe and Francis turbine. The report, "Gassovermetning i vassdrag – en kunnskapsoppsummering" [1], published in 2018, recommend pressure loss measurements at intake trash rack in combination with TDG monitoring in the plants outlet river as mitigations, where air entrainment is initiated by covered trash rack. The mitigation principle is described to be promising but not concluded, and in general, several topics related to supersaturation in rivers is relevant for further research [1]. This thesis have investigated ifmeasurement of air entrainment through intake air vents can be an alternativemethod to indirectly detect supersaturation fromthe plants outletwhere air entrainment is initiated by covered trash rack. Two field tests have been performed at Grønhaug Kraftverk AS to investigate the measurement principles and plant behavior at covered trash rack with the following air entrainment at intake. Coverage of trash rack have been done manually to simulate situations where trash rack is highly attached by e.g. debris and leaves. The first field tests have been performed with abnormal operation conditions at low discharge. The second test utilized higher discharge to gain tests result from plant behavior at normal operation conditions. Results from field tests at Grønhaug plant indicate that measurement of air flow through intake air vent can be an alternative and simple method to detect release of TDG supersaturation from the plants outlet, with submerged intake as a prerequisite. Further, test result is used to assess air ventmeasurement principle against head loss measurements at trash rack and TDG monitoring in the plants outlet. Obtained results is also used to investigate possible design improvements to avoid air entrainment at intake, and in more detail parameters that initiate and stop air entrainment at intake.Masteroppgave i energiENERGI399MAMN-ENER

Seasonal CO2 exchange in a coastal heathland in western Norway – effects of drought and bryophyte removal

Climate models project that Western Norway will experience warmer temperatures with more frequent and extreme drought periods during the 21st century. Such climatic changes are likely to alter many vital ecosystem processes, such as plant CO2 sequestration and soil carbon storage, which ultimately may lead to a shift in ecosystem function. In Western Norway, coastal heathlands contain relatively large amounts of soil carbon due to their cold and wet climate, resulting in low microbial decomposition rates relative to plant productivity. In a warmer and drier climate, the carbon balance of coastal heathlands could be particularly vulnerable to changes, potentially shifting these ecosystems from being net sinks of atmospheric carbon to net sources. Here, we measured seasonal variation in ecosystem CO2 fluxes from above- and belowground sources in a coastal heathland site near Lygra/Bergen, Norhordland. To investigate how extreme drought events may affect future carbon dynamics in this ecosystem, we constructed an experimental drought gradient, manipulating rainfall inputs by 0, 50, and 90% using rainout shelters. Bryophytes constitute a major functional group in coastal heathlands and bryophyte water holding capacity and soil insulation properties could potentially mediate effects of drought stress on ecosystem carbon balance. To investigate the role of bryophytes in a drier climate, we also removed bryophyte cover in a factorial setup within our drought gradient. Results show limited response to treatment where an effect could only be detected statistically for net ecosystem exchange. Ecosystem respiration, gross ecosystem production and soil respiration showed no significance to either bryophyte removal or drought treatment. Ultimately the results from this study will be part of increased understanding of drought effects on the coastal heathlands but also to piecing apart how carbon storage in other similar ecosystems will react to projected changesMasteroppgåve i biologiBIO399MAMN-BI

Residential Photovoltaic Systems in Norway: Household Knowledge, Preferences and Willingness to Pay

Solar power or photovoltaic (PV) systems have emerged as a leading low-carbon energy technology worldwide, but the deployment of residential PV systems in Norway has lagged behind other Scandinavian countries. Therefore, the Norwegian market provides an opportunity to gain insights on the demand factors that determine residential PV adoption. This paper presents results from a stated-preference survey designed to elicit household knowledge, preferences and willingness to pay for residential PV systems. Results suggest that meaningful growth in residential PV capacity depends greater knowledge among households, continued advances in technology, clarity with the grid tariff and stronger support systems. A review of recent experiences in the field corroborates the important role of effective regulatory structures and support programs

Residential Photovoltaic Systems in Norway: Household Knowledge, Preferences and Willingness to Pay

Solar power or photovoltaic (PV) systems have emerged as a leading low-carbon energy technology worldwide, but the deployment of residential PV systems in Norway has lagged behind other Scandinavian countries. Therefore, the Norwegian market provides an opportunity to gain insights on the demand factors that determine residential PV adoption. This paper presents results from a stated-preference survey designed to elicit household knowledge, preferences and willingness to pay for residential PV systems. Results suggest that meaningful growth in residential PV capacity depends greater knowledge among households, continued advances in technology, clarity with the grid tariff and stronger support systems. A review of recent experiences in the field corroborates the important role of effective regulatory structures and support programs

Developmental stages of the ballan wrasse from first feeding through metamorphosis: Cranial ossification and the digestive system

We have described six developmental stages for the ballan wrasse, from the first feeding until the juvenile stage, supported by specific descriptions of cranial ossification, maturation of the digestive tract, and growth-correlated stages. The initial formation and development of bones are closely linked to the functional anatomical structures required for the mechanics of its feeding behavior and ingestion, particularly the jaws and branchial regions involved in opening the mouth and capturing food particles. The overall ontogeny of the cranial structure compares to that of other teleosts. The cranial ossification of the ballan wrasse skull and the development of its dentary apparatus—first pharyngal teeth and later oral teeth—is linked to the development of the digestive system and to their feeding habits, from preying on zooplankton to feeding on crustaceans and invertebrates on rocks and other substrates. As ballan wrasse is a nibbler, eating small meals, the digestive tract is short compared to the length of the fish; there is no stomach or peptic digestion and also no distinctive bulbus and pyloric ceca. The liver and exocrine pancreas and their outlets terminating in the lumen of the most anterior part of the intestine are important in the digestive process and develop with a larger volume than that in gastric teleosts, relative to the digestive system.publishedVersio

Risikovurdering av AMS. Kartlegging av informasjonssikkerhetsmessige sårbarheter i AMS

-Denne rapporten presenterer en overordnet risikovurdering av Avaserte Måle- og Styringssystemer (AMS) knyttet til hvilke konsekvenser det kan ha for kraftforsyningen at AMS utsettes for informasjonssikkerhetbrudd. Vurderingen er hovedsaklig gjort for AMS basisfunksjoner, som er å registrere måledata hos kunde og overføre disse til nettselskapet, samt bryting/struping av effektuttaket i det enkelte målepunkt

Unsteady-state CO2 foam injection for increasing enhanced oil recovery and carbon storage potential

The efficiency of CO2 injection for enhanced oil recovery and carbon storage is limited by severe viscosity and density differences between CO2 and reservoir fluids and reservoir heterogeneity. In-situ generation of CO2 foam can improve the mobility ratio to increase oil displacement and CO2 storage capacity in geological formations. The aim of this work was to investigate the ability of CO2 foam to increase oil production and associated CO2 storage potential, compared to other CO2 injection methods, in experiments that deploy field-scale injection strategies. Additionally, the effect of oil on CO2 foam generation and stability was investigated. Three different injection strategies were implemented in the CO2 enhanced oil recovery and associated CO2 storage experiments: pure CO2 injection, water-alternating-gas and surfactant-alternating-gas. Foam generation during surfactantalternating-gas experiments showed reduced CO2 mobility compared to water-alternatinggas and pure CO2 injections indicated by the increase in apparent viscosity. CO2 foam increased oil recovery by 50% compared to pure CO2 injection and 25% compared to water-alternating-gas. In addition, CO2 storage capacity increased from 12% during pure CO2 injection up to 70% during surfactant-alternating-gas injections. Experiments performed at high oil saturations revealed a delay in foam generation until a critical oil saturation of 30% was reached. Oil/water emulsions in addition to CO2 foam generation contributed to CO2 mobility reduction resulting in increased CO2 storage capacity with foam.Cited as: Sæle, A., Graue, A., Alcorn, Z. P. Unsteady-state CO2 foam injection for increasing enhanced oil recovery and carbon storage potential. Advances in Geo-Energy Research, 2022, 6(6): 472-481. https://doi.org/10.46690/ager.2022.06.0