9 research outputs found

    Pipe Viscometer for Continuous Viscosity and Density Measurement of Oil Well Barrier Materials

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    The barrier material is a crucial component for wells, as it provides mechanical support to the casing and prevents the uncontrolled flow of formation fluids, ensuring zonal isolation. One of the essential prerequisites for the success of cementing an oil and gas well is the efficient removal of in-situ fluids and their adequate replacement by the barrier material. The quality of the mud displacement is affected by both the density and the viscosity hierarchy among subsequent fluids. Consequently, accurate and reliable measurement of fluid properties can help ensure consistent large-scale mixing of cementing fluids and verification that the properties of the mixed fluid are according to plan. In this paper, we investigate the implementation of a pipe viscometer for future automated measurements of density and viscosity of materials for zonal isolation and perform a sequential validation of the viscometer that starts with small-scale batch mixing and characterization of particle-free calibration liquids, followed by conventional Class G cement and selected new barrier materials. Finally, a larger-scale validation of the pipe viscometer was performed by integrating it into a yard-scale batch mixer for in-line characterization of expanding Class G oilwell cement mixing. In all cases, flow curves derived from pipe viscosity measurements were compared with offline measurements using a rheometer and a conventional oilfield viscometer. After a series of measurements and comparisons, the investigated in-line measurement system proved adequate for viscosity estimation. The flow curve of the barrier materials showed results similar to measurements using a conventional viscometer, validating the proposed test configuration to continuously measure the rheological behavior of the barrier material. The pipe viscometer flow curves are generally found to be in good quantitative agreement with independent viscometer characterization of the fluids, although some of the pipe viscometer measurements likely exhibited entrance length effects. Future improvements to the pipe viscometer design involve the assessment of even longer pipe sections to allow full flow development at the highest shear rate range and possibly different pipe diameters to improve the measurement resolution of low-shear rate viscosity.publishedVersio

    Electric spark ignition of sensitive dust clouds in the sub 1 mJ range

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    This thesis describes a study of the minimum ignition energy (MIE) of easily ignitable dust clouds in air. The MIE is a central parameter when assessing the risk involved when handling combustible dusts. Current standard test apparatus for determining MIE of dust clouds has a lower energy limit in the range of 1-3 mJ, which is a quite severe limitation because many dusts ignite readily at this energy level. Thus, the true MIE remains unknown for a number of easily ignitable dusts. A new spark generator, capable of producing synchronised sparks of very low energies and with an integrated system for measuring spark energy, has therefore been developed and applied to a number of ignition sensitive dusts. The experiments showed that several dusts did in fact have MIEs 1-2 orders of magnitude lower than 1 mJ. The new spark generator may therefore offer a basis for developing a standard test apparatus in the low-energy region. An investigation of a possible spark triggering mechanism that may take place in industrial practice has also been performed, and using this method, MIEs of several dusts were determined. Unlike the conventional method for determining MIE in the laboratory, the delay between dust dispersion and spark discharge was not a degree of freedom. In stead, the transient dust cloud was used to initiate spark breakdown between electrodes set at a high voltage lower than breakdown in pure air. As would be expected, the MIEs found by this method were somewhat higher than those obtained using conventional methods. This was ascribed to the non-optimal conditions for ignition at sparkover, which is believed to be closer to the mechanism of accidental electrostatic spark initiation in an industrial plant. There optimal independent dust dispersion and artificial spark triggering is not a realistic scenario. However, even when using this non-optimal method of spark triggering, MIEs below 1 mJ were found

    Dynamic repositioning in floating wind farms

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    The potential for harvesting Norwegian offshore wind power resourcesis undoubtably tremendous, however, currently limited by the cost of energy especially at deep waters. A general challenge for wind power production is the so-called wake effect, in which up-wind turbines shadow downstream neighbours. When moving into the domain of floating offshore wind power, the fact that turbines are not fixed to the seafloor may open new opportunities. Specifically, the ability of moving downstream turbines out of detrimental wakes may allow for higher energy output than for fixed turbines with the same spacing. Simulation studies described in the literature suggest that horizontal repositioning of floating wind turbines as the wind direction changes could be an attractive option to increase the power output. In the present study, simple simulations using readily available tools confirm this. Further, the potential gain of vertically displacing individual turbines has been investigated in current simulations, complementary to other studies in the literature only considering horizontal repositioning. The current study has been organized in three main activities. First, an initial study with simple simulations and engineering type wake models has been performed. In this, the possible energy gains of horizontal and vertical repositioning of downstream turbines has been evaluated. Through this, rough estimates were found regarding order of magnitude of movement required to achieve significant energy gains, both through simplified two-turbine configurations and more realistic wind park scenarios. Second, a concept evaluation was done to identify main challenges and options relevant for implementation of the dynamic repositioning. Different floating wind turbine concepts were considered regarding horizontal and vertical movability, control mechanisms to enable displacement, mooring/anchoring requirements, cabling etc. The evaluation also included an assessment of existing simulation models for wind field description and energy production, including turbine interactions, and dynamic properties such as turbulence intensity and its impact on structural loading/fatigue. When introducing the additional degree of freedom of varying turbine position, there is a clear need to deploy simulation tools that can accurately capture the wind field dynamics and at the same time be sufficiently fast for frequent wind field updates. The third activity has been on defining a full research project to bring the concept closer to industrial realization. This includes description of state of the art, project contents and organization. In the proposed project, the focus is on modelling of the wind field and turbine dynamics, development of optimization tools and methods for assessment of cost/benefit, and establishing software tools for case studies and concept evaluation. It is believed that there is a great potential of the proposed concept of dynamic repositioning the floating wind turbines relative to each other, but there is clearly a need to bring this a step further through in-depth studies, development of new methods and qualification of technical and economic implications.publishedVersio

    Dynamic repositioning in floating wind farms

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    The potential for harvesting Norwegian offshore wind power resourcesis undoubtably tremendous, however, currently limited by the cost of energy especially at deep waters. A general challenge for wind power production is the so-called wake effect, in which up-wind turbines shadow downstream neighbours. When moving into the domain of floating offshore wind power, the fact that turbines are not fixed to the seafloor may open new opportunities. Specifically, the ability of moving downstream turbines out of detrimental wakes may allow for higher energy output than for fixed turbines with the same spacing. Simulation studies described in the literature suggest that horizontal repositioning of floating wind turbines as the wind direction changes could be an attractive option to increase the power output. In the present study, simple simulations using readily available tools confirm this. Further, the potential gain of vertically displacing individual turbines has been investigated in current simulations, complementary to other studies in the literature only considering horizontal repositioning. The current study has been organized in three main activities. First, an initial study with simple simulations and engineering type wake models has been performed. In this, the possible energy gains of horizontal and vertical repositioning of downstream turbines has been evaluated. Through this, rough estimates were found regarding order of magnitude of movement required to achieve significant energy gains, both through simplified two-turbine configurations and more realistic wind park scenarios. Second, a concept evaluation was done to identify main challenges and options relevant for implementation of the dynamic repositioning. Different floating wind turbine concepts were considered regarding horizontal and vertical movability, control mechanisms to enable displacement, mooring/anchoring requirements, cabling etc. The evaluation also included an assessment of existing simulation models for wind field description and energy production, including turbine interactions, and dynamic properties such as turbulence intensity and its impact on structural loading/fatigue. When introducing the additional degree of freedom of varying turbine position, there is a clear need to deploy simulation tools that can accurately capture the wind field dynamics and at the same time be sufficiently fast for frequent wind field updates. The third activity has been on defining a full research project to bring the concept closer to industrial realization. This includes description of state of the art, project contents and organization. In the proposed project, the focus is on modelling of the wind field and turbine dynamics, development of optimization tools and methods for assessment of cost/benefit, and establishing software tools for case studies and concept evaluation. It is believed that there is a great potential of the proposed concept of dynamic repositioning the floating wind turbines relative to each other, but there is clearly a need to bring this a step further through in-depth studies, development of new methods and qualification of technical and economic implications

    GeoWell - Innovative Materials and Designs for Long-life High-temperature Geothermal Wells

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    International audienceThe GeoWell research project is funded through the EC-Horizon 2020 programme addressing various aspects of new and enhanced technology for the design and operation of high-temperature geothermal wells. These include cement slurry design, casing material selection, coupling of casings, downhole temperature and strain measurements in real time using fibre optic technologies, as well as novel methods for risk assessment with respect to well planning, design and operation of geothermal wells.The research is focused on both conventional geothermal production wells and deeper wells, where the pressure is as high as 150 bar and temperatures can exceed 400 ¬įC. The technologies under development and material candidates are tested under simulated conditions in laboratories and partly in-situ in existing geothermal environment

    Vestlandet som ledende milj√łvennlig energiregion

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    Denne rapporten fra IRIS er utarbeidet til Vestlandskonferansen 2008. Rapporten ser p√• hvilke forutsetninger Vestlandet har som milj√łvennlig energiprodusent, hva som er status i dag og hvilke muligheter regionen har fremover. Intensjonen er at rapporten skal stimulere til videre engasjement p√• dette viktige omr√•det. Innenfor rammen av prosjektet tar vi for oss et utvalg av problemstillinger som vi vurderer som sentrale. Tidshorisonten for utsiktene er 2020.Vestlandskonferanse

    Vestlandet som ledende milj√łvennlig energiregion

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    Denne rapporten fra IRIS er utarbeidet til Vestlandskonferansen 2008. Rapporten ser p√• hvilke forutsetninger Vestlandet har som milj√łvennlig energiprodusent, hva som er status i dag og hvilke muligheter regionen har fremover. Intensjonen er at rapporten skal stimulere til videre engasjement p√• dette viktige omr√•det. Innenfor rammen av prosjektet tar vi for oss et utvalg av problemstillinger som vi vurderer som sentrale. Tidshorisonten for utsiktene er 2020

    Energy for Norwegian greenhouse industry ‚Äď Use of natural gas as energy source and for CO2 supply

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    Norsk gartnerin√¶ring bruker anslagsvis 1 000 GWh per √•r. Planteproduksjon i veksthus her i landet har stort behov for elektrisk energi og avhengig av kultur og produksjonsopplegg varierer andelen elektrisk energi fra 50-80 %.. Naturgass er blitt et supplement til elektrisk energi i Rogaland de siste √•rene. I arbeidet med √• sikre veksthusn√¶ringen tilgang p√• elektrisk kraft kan kraft/varme-anlegg v√¶re et alternativ, ettersom plantene kan nyttiggj√łre seg CO2 i avgassen. I utredningen er det skissert et fors√łksanlegg for testing av energil√łsninger for veksthus basert p√• naturgass og aktuelt utstyr for produksjon og oppsamling av energi for senere bruk.Energi til norsk veksthusn√¶ring - bruk av naturgass som energib√¶rer og CO2-kildeEnergy for Norwegian greenhouse industry ‚Äď Use of natural gas as energy source and for CO2 supplypublishedVersio

    lntegration of fuel-based energy system at offshore oil & gas installation with wind farms, main grid and other renewable energy systems

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    This report present ideas of combined wind power and combustion based power system for offshore oil and gas installations. The challenges relates to two types of concepts: stand-alone system and grid-connected system are also presented. The report can be used for further extension for a possible project proposal related to this topic.Cens
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