EFFECT OF HYDRATE FORMATION/DISSOCIATION ON EMULSION STABILITY USING DSC AND VISUAL TECHNIQUES

The flow assurance industry is progressively moving away from avoidance of hydrate formation towards risk management. Risk management allows hydrates to form but prevents hydrates from agglomerating and forming a plug, or delays hydrate formation within the timescale of the residence time of the water in the hydrate-prone section of the flow line. A key factor in risk management for an oil-dominated system is the stability of the emulsified water with gas hydrate formation. It is shown using Differential Scanning Calorimetry (DSC) that gas hydrate formation and dissociation has a destabilizing effect on W/O emulsions, and can even lead to a free water phase through agglomeration and coalescence of dissociated hydrate particles. Gas hydrate formation/dissociation has been shown to cause rapid hydrate agglomeration and emulsion destabilization. High asphaltene content crude oils are shown to resist hydrate destabilization of the emulsion.Non UBCUnreviewe

A NOVEL APPROACH TO MEASURING METHANE DIFFUSIVITY THROUGH A HYDRATE FILM USING DIFFERENTIAL SCANNING CALORIMETRY

The avoidance of hydrate blockages in deepwater subsea tiebacks presents a major technical challenge with severe implications for production, safety and cost. The successful prediction of when and where hydrate plugs form could lead to substantial reductions in the use of chemical inhibitors, and to corresponding savings in operational expenditure. The diffusivity of the gas hydrate former (methane) or the host molecule (water), through a hydrate film is a key property for such predictions of hydrate plug formation. In this paper, a novel application of Differential Scanning Calorimetry is described in which a hydrate film was allowed to grow at a hydrocarbon-water interface for different hold-times. By determining the change in mass of the hydrate film as a function of hold-time, an effective diffusivity could be inferred. The effect of the subcooling, and of the addition of a liquid hydrocarbon layer were also investigated. Finally, the transferability of these results to hydrate growth from water-in-oil emulsions is discussed.Non UBCUnreviewe

HYDRATE NUCLEATION MEASUREMENTS USING HIGH PRESSURE DIFFERENTIAL SCANNING CALORIMETRY

Understanding when hydrates will nucleate has notable importance in the area of flow assurance. Attempts to model hydrate formation in subsea pipelines currently requires an arbitrary assignment of a nucleation subcooling. Previous studies showed that sII hydrate containing a model water-soluble former, tetrahydrofuran, would nucleate over a narrow temperature range of a few degrees with constant cooling. It is desirable to know if gas phase hydrate formers, which are typically more hydrophobic and hence have a very low solubility in water, also exhibit this nucleation behavior. In this study, differential scanning calorimetry has been applied to determine the hydrate nucleation point for gas phase hydrate formers. Constant cooling ramps and isothermal approaches were combined to explore the probability of hydrate nucleation. In the temperature ramping experiments, methane and xenon were used at various pressures and cooling rates. In both systems, hydrate nucleation occurred over a narrow temperature range (2-3°C). Using methane at lower pressures, ice nucleated before hydrate; whereas at higher pressures, hydrate formed first. A subcooling driving force of around 30°C was necessary for hydrate nucleation from both guest molecules. The cooling rates (0.5-3°C/min) did not show any statistically significant effect on the nucleation temperature for a given pressure. The isothermal method was used for a methane system with pure water and a water-in-West African crude emulsion. Two isotherms (-5 and -10°C) were used to determine nucleation time. In both systems, the time required for nucleation decreased with increased subcooling.Non UBCUnreviewe

WildMeOrg/houston: Codex 2.1.0

<p>Update major features include Codex ID, change log, sighting flow simplification, search extensions, and accessibility improvements!</p> <h2>What's Changed</h2> <ul> <li>AutogeneratedName continued by @naknomum in https://github.com/WildMeOrg/houston/pull/881</li> <li>additions to ia-config/ files by @naknomum in https://github.com/WildMeOrg/houston/pull/892</li> <li>Issue 880: individual merge vs AutogeneratedName by @naknomum in https://github.com/WildMeOrg/houston/pull/893</li> <li>Integrity checks by @naknomum in https://github.com/WildMeOrg/houston/pull/894</li> <li>882, 883: AutogeneratedName - Sighting/Individual search support by @naknomum in https://github.com/WildMeOrg/houston/pull/895</li> <li>869, 870: export by @naknomum in https://github.com/WildMeOrg/houston/pull/897</li> <li>bugfixes related to exporting by @naknomum in https://github.com/WildMeOrg/houston/pull/903</li> <li>899/900: Sighting search to include Encounter values by @naknomum in https://github.com/WildMeOrg/houston/pull/901</li> <li>bugfix for customFields in export by @naknomum in https://github.com/WildMeOrg/houston/pull/904</li> <li>907/908: Individual search results to include most recent sighting fields by @naknomum in https://github.com/WildMeOrg/houston/pull/909</li> <li>906: deletion of Annotation also removes it from AssetGroupSightings by @naknomum in https://github.com/WildMeOrg/houston/pull/910</li> <li>911: normalize adoptionName in ElasticSearch by @naknomum in https://github.com/WildMeOrg/houston/pull/912</li> <li>888: Sighting match_state by @naknomum in https://github.com/WildMeOrg/houston/pull/915</li> <li>allow admin to delete individuals with public sightings by @naknomum in https://github.com/WildMeOrg/houston/pull/918</li> <li>566: add numberIndividuals to Sighting search results by @naknomum in https://github.com/WildMeOrg/houston/pull/922</li> <li>875: ensure that site.species site-settings does not remove in-use taxonomy by @naknomum in https://github.com/WildMeOrg/houston/pull/926</li> <li>overhaul Sighting.stage usage by @naknomum in https://github.com/WildMeOrg/houston/pull/928</li> </ul> <p><strong>Full Changelog</strong>: https://github.com/WildMeOrg/houston/compare/v2.0.0...v2.1.0</p&gt

Advances in multidisciplinary therapy for meningiomas

Surgery has long been established as the first-line treatment for the majority of symptomatic and enlarging meningiomas, and evidence for its success is derived from retrospective case series. Despite surgical resection, a subset of meningiomas display aggressive behavior with early recurrences that are difficult to treat. The decision to radically resect meningiomas and involved structures is balanced against the risk for neurological injury in patients. Radiation therapy has largely been used as a complementary and safe therapeutic strategy in meningiomas with evidence primarily stemming from retrospective, single-institution reports. Two of the first cooperative group studies (RTOG 0539 and EORTC 22042) evaluating the outcomes of adjuvant radiation therapy in higher-risk meningiomas have shown promising preliminary results. Historically, systemic therapy has resulted in disappointing results in meningiomas. However, several clinical trials are under way evaluating the efficacy of chemotherapies, such as trabectedin, and novel molecular agents targeting Smoothened, AKT1, and focal adhesion kinase in patients with recurrent meningiomas