Explicit tracking of CO2-flow at the core scale using micro-Positron Emission Tomography (μPET)

Safe subsurface sequestration of carbon dioxide (CO2) is becoming increasingly important to meet climate goals and curb atmospheric CO2 concentrations. The world-wide CO2 storage capacity in carbonate formations is significant; within deep, saline aquifers and through several CO2-enhanced oil recovery projects, with associated CO2 storage. Carbonates are complex, both in terms of heterogeneity and reactivity, and improved core scale and sub core-scale analysis of CO2 flow phenomena is necessary input to simulators, aiming to establish large-scale behavior. This paper presents a recent advancement in in-situ imaging of CO2 flow, utilizing high-resolution micro-Positron Emission Tomography and radioactive tracer [11C]arbon dioxide to explicitly track CO2 during dynamic flow and subsequent trapping at the core scale. Unsteady state water injection (imbibition) and CO2 injection (drainage) were performed in a low-permeable chalk core at elevated pressure conditions. Short-lived radioisotopes were used to label water and CO2, respectively, and facilitated explicit tracking of each phase separately during single phase injection. Local flow patterns and dynamic spatial fluid saturations were determined from in-situ imaging during each experimental step. Initial miscible displacement revealed displacement heterogeneities in the chalk core, and dynamic image data was used to disclose and quantify local permeability variations. Radial permeability variations influenced subsequent flow patterns, where CO2 predominantly flooded the higher-permeability outer part of the core, leaving a higher water saturation in the inner core volume. Injection of water after CO2 flooding is proposed to be the most rapid and effective way to ensure safe storage, by promoting capillary trapping of CO2. PET imaging showed that presence of CO2 reduced the flow of water in higher-permeability areas, improving sweep efficiency and promoting a nearly ideal core-scale displacement. Alternate injections of water and gas is also expected to improve sweep efficiency and contribute to improved oil recovery and CO2 storage on larger scales. Sub-core analysis showed that residually trapped CO2 was evenly distributed in the chalk core, occupying 40% of the pore volume after ended water injection. Micro-Positron Emission Tomography yielded excellent small-scale resolution of both water and CO2 flow, and may contribute to unlocking fluid flow dynamics and determining mechanisms on the millimeter scale; presenting a unique opportunity in experimental core-scale evaluations of CO2 storage and security.publishedVersio

Socioeconomic position and adolescent anxiety and depression

Bacheloroppgave folkehelse, 2016Forfatter Malin Hvam Haugen Oppgavens tittel Sosioøkonomisk posisjon og angst og depresjon hos ungdom. Problemstilling Hvilken betydning kan foreldres sosioøkonomiske posisjon ha for utvikling av angst og depresjon blant ungdom? Teori Sosial ulikhet i helse, sosiale miljøfaktorer som påvirker ens psykiske helse og hvilke måleindikatorer som brukes for sosioøkonomisk posisjon teoretiseres i denne delen. I tillegg inngår psykiske lidelser og psykiske plager i teoridelen, samt kort om ungdomstiden som en eventuell sårbar periode i livet. Metode I denne oppgaven anvendes litteraturstudie som metode. Datapresentasjon og diskusjon I datapresentasjonen presenteres de fire artiklene som inngår i litteraturstudiet. Videre diskuteres de gjeldende artiklene opp mot teori. Konklusjon Det konkluderes med at foreldres sosioøkonomiske posisjon er av betydning for utvikling av angst og depresjon hos ungdom. Det foreligger få årsaksfaktorer, derimot argumenteres det for ungdomstiden som en sårbar periode, hvor en utsettes for økt risiko for utvikling av angst og depresjon

Multi-scale dissolution dynamics for carbon sequestration in carbonate rock samples

Carbon dioxide (CO2) sequestration in porous, sedimentary reservoirs is a key technology to mitigate emissions of anthropogenic CO2 and curb irreversible climate change. The abundance of carbonate formations, both as saline aquifers and hydrocarbon reservoirs, makes future CO2 storage in carbonate formations highly likely. The weak carbonic acid that forms when CO2 dissolves in water will, however, interact with highly reactive carbonate. Preferential flow paths may form during dissolution or calcite precipitation may reduce injectivity - both processes significantly impacting reservoir sweep efficiency. Hence, understanding the dynamics of the dissolution processes and their influence on flow properties is necessary to safely store CO2 in carbonate formations. Darcy and sub-Darcy scale dissolution kinetics were here assessed in carbonate core plugs with and without pre-existing highly permeable pathways, during multiphase flow and under relevant storage conditions. Darcy-scale dissolution and precipitation data (injectivity changes, effluent analysis and mass loss) confirmed that CO2 and brine co-injections altered the carbonate rock structure on Darcy scale, but could not determine the cause of change. Multi-modal imaging was applied to independently quantify structural changes with computed tomography (CT) and aqueous flow characteristics with positron emission tomography (PET), thereby determining injectivity dependence on local flow patterns. Formation of high permeability pathways, which was expected due to rock dissolution, was only observed in cores with pre-existing open fractures, where reactive flow was limited to the fracture plane. A good correlation between the two imaging modules was found: areas of higher porosity yielded a low-density CT signal (i.e. high number of voids present) and a high PET signal density (i.e. large volume of traced fluid present). Loss of injectivity suggested local changes in the flow pattern due to blocking of pore throats by moving particles or secondary precipitation or mineralization of dissolved ions. High-resolution PET imaging revealed cementation, that was also visible using micro-CT, hence determining sub-Darcy local flow obstructions that led to decreased Darcy scale injectivity. Multi-modal imaging, where core characteristics, such as large vugs and cementation, can be independently determined by complementary modalities, may therefore be a useful tool to quantify reactive flow and resulting dissolution in rock samples.publishedVersio

Direct comparison of numerical simulations and experiments of CO2_2 injection and migration in geologic media: Value of local data and predictability

The accuracy and robustness of numerical models of geologic CO$_2$ sequestration are almost never quantified with respect to direct observations that provide a ground truth. Here, we conduct CO$_2$ injection experiments in meter-scale, quasi-2D tanks with porous media representing stratigraphic sections of the subsurface, and combine them with numerical simulations of those experiments. We evaluate (1) the value of prior knowledge of the system, expressed in terms of ex-situ measurements of the tank sands' multiphase flow properties (local data), to obtain an accurate simulation; and (2) the predictive capability of the matched numerical models, when applied to different settings. We match three different simulation models-each with access to an increasing level of local data-to a CO$_2$ injection experiment in tank 1 (89.7$\times$47$\times$1.05 cm). Matching is based on a quantitative comparison of CO$_2$ migration at different times from timelapse image analysis. Next, we simulate a different injection scenario in tank 1, and, finally, a different injection scenario in tank 2 (2.86$\times$1.3$\times$0.019 m), which represents an altogether different stratigraphic section. Our models can qualitatively match the CO$_2$ plume migration and convective mixing of the experimental truth. Quantitatively, simulations are accurate during the injection phase but their performance decreases with time. Using local data reduces the time required to history match. The predictive capability of matched models, however, is found to be similar. The sand-water-CO$_{2(\mathrm{g})}$ system is very sensitive to effective permeability and capillary pressure changes; where heterogeneous structures are present, accurate deterministic estimates of CO$_2$ migration are unlikely

Engineering meter-scale porous media flow experiments for quantitative studies of geological carbon sequestration

This technical note describes the FluidFlower concept, a new laboratory infrastructure for geological carbon storage research. The highly controlled and adjustable system produces a strikingly visual physical ground truth of studied processes for model validation, comparison, and forecasting, including detailed physical studies of the behavior and storage mechanisms of carbon dioxide and its derivative forms in relevant geological settings for subsurface carbon storage. The design, instrumentation, structural aspects and methodology are described. Furthermore, we share engineering insights on construction, operation, fluid considerations, and fluid resetting in the porous media. The new infrastructure enables researchers to study variability between repeated CO2 injections, making the FluidFlower concept a suitable tool for sensitivity studies on a range of determining carbon storage parameters in varying geological formations

Room-Scale CO2 Injections in a Physical Reservoir Model with Faults

We perform a series of repeated CO2 injections in a room-scale physical model of a faulted geological cross-section. Relevant parameters for subsurface carbon storage, including multiphase flows, capillary CO2 trapping, dissolution and convective mixing, are studied and quantified. As part of a validation benchmark study, we address and quantify six predefined metrics for storage capacity and security in typical CO2 storage operations. Using the same geometry, we investigate the degree of reproducibility of five repeated experimental runs. Our analysis focuses on physical variations of the spatial distribution of mobile and dissolved CO2, multiphase flow patterns, development in mass of the aqueous and gaseous phases, gravitational fingers and leakage dynamics. We observe very good reproducibility in homogenous regions with up to 97% overlap between repeated runs, and that fault-related heterogeneity tends to decrease reproducibility. Notably, we observe an oscillating CO2 leakage behavior from the spill point of an anticline and discuss the observed phenomenon within the constraints of the studied system.publishedVersio

Photoannealing of Microtissues Creates High-Density Capillary Network Containing Living Matter in a Volumetric-Independent Manner

The vascular tree is crucial for the survival and function of large living tissues. Despite breakthroughs in 3D bioprinting to endow engineered tissues with large blood vessels, there is currently no approach to engineer high-density capillary networks into living tissues in a scalable manner. Here, photoannealing of living microtissue (PALM) is presented as a scalable strategy to engineer capillary-rich tissues. Specifically, in-air microfluidics is used to produce living microtissues composed of cell-laden microgels in ultrahigh throughput, which can be photoannealed into a monolithic living matter. Annealed microtissues inherently give rise to an open and interconnected pore network within the resulting living matter. Interestingly, utilizing soft microgels enables microgel deformation, which leads to the uniform formation of capillary-sized pores. Importantly, the ultrahigh throughput nature underlying the microtissue formation uniquely facilitates scalable production of living tissues of clinically relevant sizes (&gt;1 cm3) with an integrated high-density capillary network. In short, PALM generates monolithic, microporous, modular tissues that meet the previously unsolved need for large engineered tissues containing high-density vascular networks, which is anticipated to advance the fields of engineered organs, regenerative medicine, and drug screening.</p

Integration of oncology and palliative care : a Lancet Oncology Commission

Full integration of oncology and palliative care relies on the specific knowledge and skills of two modes of care: the tumour-directed approach, the main focus of which is on treating the disease; and the host-directed approach, which focuses on the patient with the disease. This Commission addresses how to combine these two paradigms to achieve the best outcome of patient care. Randomised clinical trials on integration of oncology and palliative care point to health gains: improved survival and symptom control, less anxiety and depression, reduced use of futile chemotherapy at the end of life, improved family satisfaction and quality of life, and improved use of health-care resources. Early delivery of patient-directed care by specialist palliative care teams alongside tumour-directed treatment promotes patient-centred care. Systematic assessment and use of patient-reported outcomes and active patient involvement in the decisions about cancer care result in better symptom control, improved physical and mental health, and better use of health-care resources. The absence of international agreements on the content and standards of the organisation, education, and research of palliative care in oncology are major barriers to successful integration. Other barriers include the common misconception that palliative care is end-of-life care only, stigmatisation of death and dying, and insufficient infrastructure and funding. The absence of established priorities might also hinder integration more widely. This Commission proposes the use of standardised care pathways and multidisciplinary teams to promote integration of oncology and palliative care, and calls for changes at the system level to coordinate the activities of professionals, and for the development and implementation of new and improved education programmes, with the overall goal of improving patient care. Integration raises new research questions, all of which contribute to improved clinical care. When and how should palliative care be delivered? What is the optimal model for integrated care? What is the biological and clinical effect of living with advanced cancer for years after diagnosis? Successful integration must challenge the dualistic perspective of either the tumour or the host, and instead focus on a merged approach that places the patient's perspective at the centre. To succeed, integration must be anchored by management and policy makers at all levels of health care, followed by adequate resource allocation, a willingness to prioritise goals and needs, and sustained enthusiasm to help generate support for better integration. This integrated model must be reflected in international and national cancer plans, and be followed by developments of new care models, education and research programmes, all of which should be adapted to the specific cultural contexts within which they are situated. Patient-centred care should be an integrated part of oncology care independent of patient prognosis and treatment intention. To achieve this goal it must be based on changes in professional cultures and priorities in health care

Overlevelse av pasienter med implanterbar cardioverter defibrillator (ICD) ved Ullevål universitetssykehus 1984-2004

Survival of patients with Implantable Cardioverter Defibrillator (ICD) at Ullevål University Hospital, 1984-2004. Johanne Haugen, Malin Fredholm Langlo, Finn Hegbom. Background. In the western part of the world, cardiac arrest is a frequent cause of death. Every year 5000-8000 persons in Norway are affected. In this study we wanted to look at the survival of patients with implanted cardioverter defibrillator (ICD) at Ullevål University Hospital, in the period of 1984-2004. The primary aim of ICD-implantation is protection against sudden cardiac death caused by ventricular tachyarrhytmia. Material and method. We have observed a material of 264 ICD-patients and registered some important predictors of mortality. Patients were followed at least 6 months after the implantation. Results. The indications for ICD therapy at Ullevål University Hospital are related to clinical presentation, such as survival of sudden cardiac arrest (39%), ventricular tachycardia (27%) and syncope (27%). The overall survival after 5 years was 78%. Patients with left ventricular ejection fraction (EF) 35% (p=0,018). Survivors of cardiac arrest have an increased mortality-risk of 85% (p=0,034). An age-increase of 10 years also increased the mortality-risk with 81% (p=0,001). Interpretation. The most important predictors of survival in ICD-patients at Ullevål University Hostpital are EF, age and earlier cardiac arrest. We found a significantly lower 5-years survival of patients with EF < 35% and patients with clinical presentation of cardiac arrest. An age-increase of 10 years is also a significant riskfactor