High Temperature Field Research Articles

The role of the underburden at Elgin Franklin in the understanding of the overburden 4D signal

Elgin, Franklin, and West Franklin are high-pressure high-temperature fields located in the Central North Sea. The fields share a similar reservoir and overburden geology. During the life of the fields, they have undergone a similar depletion over time. However, each field shows a different 4D behavior in the overburden. The 4D signal on Elgin is the strongest and is located away from the wells. The Franklin 4D signal is in line with expectation as the strongest signal close to the wells. On West Franklin, the 4D signal is small and barely distinguishable from noise. To explain the differences in 4D signal between the fields, a detailed underburden salt interpretation is performed. The differences in underburden between Elgin (thick with an abundance of salt) and West Franklin (marginal underburden with proximal salt) show a strong correlation with the 4D signals of the overburden. The renewed salt interpretation is used to update a vintage geomechanical model, from which strains and stresses are computed. During the stress initialization of the geomechanical model, the underlying salt (thick sheet or salt weld) creates stress perturbations on the salt/rock interface. When the reservoir compaction is simulated, the 3D model simulates the vertical stretches differently in the overburden for the fields. The stretching varies according to the underburden thickness and presence of salt below the underburden. The results of the geomechanical modeling help explain the differences observed in the overburden 4D signal of the fields.

Structural, dielectric, and piezoelectric properties of Ce-doped Bi7Ti4.2Ta0.3W0.5O21 intergrowth ferroelectric ceramics

The Bi7-xCexTi4.2Ta0.3W0.5O21 (BTTW-BITT-xCe, x = 0.05, 0.10, 0.15, 0.20) ceramics were studied as potential materials for high-temperature applications. The microstructure, dielectric, piezoelectric and ferroelectric properties of Ce doped BTTW-BITT samples were analyzed in detail. The results indicated that an appropriate amount of Ce ion doping could inhibit the growth of grains, suppress the relaxation peak, reduce high-temperature dielectric losses, and greatly improve the piezoelectric activities. The optimal ceramics was obtained at x = 0.15, which possessed a maximum piezoelectric constant of d33 = 23.4 pC/N, a high Curie temperature of 713 °C, a loss value of 6% at 500 °C, and a favorable thermal stability of d33 = 21.1 pC/N (90% of the initial value) at 500 °C. This result indicates that BTTW-BITT-0.15Ce has great potential for applications in the high temperature fields. In addition, XPS results showed that there were two Ce valences states, Ce3+ and Ce4+present in the BTTW-BITT-xCe ceramics.

Active hydrothermal vents in the Woodlark Basin may act as dispersing centres for hydrothermal fauna

Here we report the discovery of a high-temperature hydrothermal vent field on the Woodlark Ridge, using ship-borne multibeam echosounding and Remotely Operated Vehicle (ROV) exploration. La Scala Vent Field comprises two main active areas and several inactive zones dominated by variably altered basaltic rocks, indicating that an active and stable hydrothermal circulation has been maintained over a long period of time. The Pandora Site, at a depth of 3380 m, is mainly composed of diffuse vents. The Corto site, at a depth of 3360 m, is characterized by vigorous black smokers (temperature above 360 °C). The striking features of this new vent field are the profusion of stalked barnacles Vulcanolepas sp. nov., the absence of mussels and the scarcity of the gastropod symbiotic fauna. We suggest that La Scala Vent Field may act as a dispersing centre for hydrothermal fauna towards the nearby North Fiji, Lau and Manus basins.

Laser-Induced Hydrothermal Growth of Iron Oxide Nanoparticles on Diverse Substrates for Flexible Micro-Supercapacitors

State-of-the-art microdevice fabrication requires patterned growth of functional nanomaterials on the desired position of the desired substrate. However, it is challenging, particularly in conventional hydrothermal synthesis, due to difficulties generating a local high-temperature field at the desired place. We introduce a laser-induced hydrothermal growth (LIHG) process for the rapid and selective synthesis of iron oxide nanoparticles (NPs). The substrates absorb the laser energy to generate a local high-temperature field necessary for the growth of iron oxide NPs. On various substrates, a dome-like structure comprising many iron oxide NPs is selectively synthesized within a localized temperature field. The LIHG process has several advantages for iron oxide NP growth, including rapidity, seedless growth, substrate compatibility, position selectivity, and patterning availability. Using its advantages, the LIHG process is used to fabricate flexible micro-supercapacitors based on laser-carbonized colorless polyimide films with iron oxide NPs.

Quantitative assessment on the grain appearance of a new Japanese rice cultivar ‘Niji-no-kirameki’ with a novel heat-avoidance mechanism during ripening

There is an increased demand for developing a heat-resilient cultivar with high palatability and acceptable grain yield to cope with the impacts of progressive changes in global climate conditions. This study attempted to quantify the heat resilience level and explore the heat resilient mechanism of ‘Niji-no-kirameki’, a new Japanese cultivar with heat resilience during ripening, and compare it with the leading Japanese cultivar ‘Koshihikari’. Multi-environmental testing on grain appearance under diverse high temperature field conditions across three prefectures revealed superior performance of ‘Niji-no-kirameki’ compared to ‘Koshihikari’, especially when the average of daily mean temperatures during the first 20 days after heading was over 27 °C, a general threshold temperature previously reported to decrease grain appearance in ‘Koshihikari’. Starch properties such as amylose content and amylopectin chain length distribution were similar between cultivars across seasons. Severely chalked grains by high temperature stress had lower protein content and 13 kDa prolamin content in the grains, suggesting that inter-relationships between starch and storage protein biosynthesis affect the formation of the chalky phenotype irrespective of cultivars with different heat resilience levels. As a possible heat resilience mechanism, a novel biological response of ‘Niji-no-kirameki’ for preventing an increase in panicle temperature to rising temperatures during ripening was found. It is assumed that the erect plant phenotype until maturity concealing panicles inside the canopy could create a cooler environment for panicles of ‘Niji-no-kirameki’ during ripening. We conclude that ‘Niji-no-kirameki’ is a promising cultivar for the improvement of grain appearance in the heat-vulnerable regions of Japan.

Multiphysics Mathematical Modeling and Flow Field Analysis of an Inflatable Membrane Aeroshell in Suborbital Reentry

In the present study, a multiphysics mathematical model for reproducing the flow field characteristics of an inflatable aeroshell was developed to study the aerodynamic properties of the flow around a membrane reentry vehicle. Firstly, the configuration and flight sequence of a membrane reentry vehicle used in the experiment were introduced. Secondly, mathematical equations of multiphysics fields, such as the Navier–Stokes equations, the heat conduction equation, and the membrane deformation equation, were introduced and numerically solved. The variation characteristics of the flow properties during the aerodynamic heating of a membrane vehicle were studied and discussed in detail under the conditions of different flight altitudes. The results showed that for the membrane vehicle, the high-temperature flow field at the front of its capsule was in a state of thermal non-equilibrium with the decrease of flight altitude and its membrane deformation degree was proportional to the pressure. The translational temperature and electron number density of the plasma flow around the aeroshell remained at a relatively low level for the membrane vehicle so that the blackout phenomenon scarcely occurred during its atmospheric reentry.

Study on high-temperature mechanical properties of W25Re alloy

Tungsten rhenium alloy is widely used in aerospace, weapon electronics, and other high-temperature fields. W25Re alloy bars were prepared by powder metallurgy combined with the rolling deformation process. The mechanical properties of W25Re alloy were studied. The results show that rolled W25Re alloy bars have excellent mechanical properties. The tensile strength at room temperature is up to 1650 MPa and the elongation is 15%. As temperature increases, the tensile strength of W25Re alloy decreases rapidly, and the elongation first increases and then decreases. However, at 2000 °C, the tensile strength of more than 200 MPa and elongation of 16% can still be maintained. The fracture morphology shows that the dimples disappear and dynamic recrystallization occurs at 1600 °C and that the grain grows further at 2000 °C. The analysis shows that with increasing temperature, the increasing grain size and decreasing grain adhesion lead to decreasing strength and plasticity at 2000 °C.

On-Line Multi-Frequency Electrical Resistance Tomography (mfERT) Device for Crystalline Phase Imaging in High-Temperature Molten Oxide.

An on-line multi-frequency electrical resistance tomography (mfERT) device with a melt-resistive sensor and noise reduction hardware has been proposed for crystalline phase imaging in high-temperature molten oxide. The melt-resistive sensor consists of eight electrodes made of platinum-rhodium (Pt-20mass%Rh) alloy covered by non-conductive aluminum oxide (Al2O3) to prevent an electrical short. The noise reduction hardware has been designed by two approaches: (1) total harmonic distortion (THD) for the robust multiplexer, and (2) a current injection frequency pair: low and high , for thermal noise compensation. THD is determined by a percentage evaluation of k-th harmonic distortions of ZnO at .1~10,000 Hz. The and are determined by the thermal noise behavior estimation at different temperatures. At 00 Hz, the THD percentage is relatively high and fluctuates; otherwise, THD dramatically declines, nearly reaching zero. At the determined 10,000 Hz and 1,000,000 Hz, thermal noise is significantly compensated. The on-line mfERT was tested in the experiments of a non-conductive Al2O3 rod dipped into conductive molten zinc-borate (60ZnO-40B2O3) at 1000~1200 C. As a result, the on-line mfERT is able to reconstruct the Al2O3 rod inclusion images in the high-temperature fields with low error, = 5.99%, at 1000 C, and an average error = 9.2%.

Effect of the Flame Retardants and Glass Fiber on the Polyamide 66/Polyphenylene Oxide Composites.

In this work, polyamide 66/polyphenylene oxide (PA66/PPO) composites, including the flame retardants 98 wt% aluminum diethylphosphinate + 2 wt% polydimethylsiloxane (P@Si), Al(OH)3-coated red phosphorus (RP*), and glass fiber (GF), were systematically studied, respectively. The limiting oxygen index (LOI), UL-94 vertical burning level, and thermal and mechanical properties of the PA66/PPO composites were characterized. The results showed that the P@Si and RP flame retardants both improved the LOI value and UL-94 vertical burning level of the PA66/PPO composites, and PA66/PPO composites passed to the UL-94 V-0 level when the contents of P@Si and RP* flame retardants were 16 wt% and 8 wt%. On the other hand, the mechanical properties of the PA66/PPO composites were reduced from a ductile to a brittle fracture mode. The addition of GF effectively made up for these defects and improved the mechanical properties of the PA66/PPO composites containing the P@Si and RP*, but it did not change the fracture mode. P@Si and RP* flame retardants improved the thermal decomposition of PA66/PPO/GF composites and reduced the maximum mass loss rates, showing that the PA66/PPO/GF composites containing the P@Si and RP* flame retardants could be used in higher-temperature fields.

Hydrogen migration in BaTiO3-based dielectrics under high humidity and electric field bias

This study investigates the possibility of hydrogen migration in BaTiO3-based dielectrics to improve the electrical reliability of multi-layer ceramic capacitors under conditions of high temperature, humidity, and electric field bias. It was observed that the deuterium in the dielectric drifted and migrated with the electric field, suggesting that deuterium exists as D+. The activation energy was found to be 0.34 eV, which is lower than that observed in previous studies. This finding offers a better understanding of the mechanism behind the migration of deuterium in a dielectric, which is highly relevant to future research in dielectrics and electronic components.

Study on the thermoelectric properties of p-type doped CsCdF3 and CsHgF3 with quartic anharmonicity

The cubic perovskite materials CsCdF3 and CsHgF3 have extremely low lattice thermal conductivity, but due to the limitations of the previous calculation methods. The CsHgF3 have been considered unstable for a long time. Through self-consistent phonon theory and compressed sensing technology, we verified the stability of CsHgF3, and studied the thermoelectric transport characteristics of p-type doped CsCdF3 and CsHgF3 based on the first principles calculations combined with the Boltzmann transport equation. In addition, we also discussed the influence of the quartic anharmonicity on the lattice dynamics and thermal transport properties of CsHgF3. The results show that the halogen elements in CsHgF3 have strong quartic anharmonicity and directly affect the stability of the material. The lattice thermal conductivity of CsCdF3 and CsHgF3 calculated by self-consistent phonon theory are 2.03 W/mK and 1.23 W/mK at 300 K, respectively, which are higher than the results obtained by the traditional method, but still lower than most existing classical thermoelectric materials. By combining the obtained thermoelectric coefficients, the calculated thermoelectric figure of merit can reach 0.799 and 1.275 for CsCdF3 and CsHgF3 at 700 K, which shows that CsCdF3 and CsHgF3 have potential development prospects in high-temperature thermoelectric application field.

Significance of radiative magnetohydrodynamic flow of suspended PEG based ZrO2 and MgO2 within a conical gap

The underlying intension of this study is to oversee the flow and thermal management of hybrid nanofluid (Magnesium oxide+ Zirconium oxide+ polyethylene glycol) within a conical gap among a cone and a disk. Forced convection is examined for two situations (a) rotating disk and the stationary cone; (b) stationary disk and the rotating cone. The dimensionless differential system for the proposed model is numerically simulated with a shooting procedure (RK 4th order). Outcomes are explained through graph and tables. The main outcomes of this study are found to be – Rotating disk and stationary cone show higher temperature field for increasing estimations of the radiation parameter () and the magnetic parameter () near the boundary. Hence, for heat enhancement, one can use the disk – cone model. Furthermore, increases in and shows an increment in Nusselt number at the cone surface compared to that at the disk surface. The desired cooling in the disk and cone device could be attained by keeping the cone fixed and the disk rotating and by maintaining the surface temperature constant. It is perceived that improvement in the volume fraction of and nanoparticles significantly enhanced velocity of base fluid and heat transfer rate.

Integrating Stable Isotopes with Mean Residence Time Estimation to Characterize Groundwater Circulation in a Metamorphic Geothermal Field in Yilan, Taiwan

This paper presents a water circulation model by combing oxygen and hydrogen stable isotopes and mean residence time (MRT) estimation in a high-temperature metamorphic geothermal field, Tuchen, in Yilan, Taiwan. A total of 18 months of oxygen and hydrogen stable isotopes of surface water and thermal water show the same variation pattern, heavier values in summer and lighter values in the rest of the year. A shift of δ18O with a relative constant δD indicates the slow fluid–rock interaction process in the study area. Two adjacent watersheds, the Tianguer River and Duowang River, exhibit different isotopic values and imply different recharge altitudes. The seasonal variation enabled us to use stable isotope to estimate mean residence time of groundwater in the study area. Two wells, 160 m and 2200 m deep, were used to estimate mean residence time of the groundwater. Deep circulation recharges from higher elevations, with lighter isotopic values, 5.9‰ and 64‰ of δ18O and δD, and a longer mean residence time, 1148 days, while the shallow circulation comes from another source with heavier values, 5.7‰ and 54.4‰ of δ18O and δD, and a shorter mean residence time, 150 days. A two-circulation model was established based on temporal and spatial distribution characteristics of stable isotopes and the assistance of MRT. This study demonstrates the usefulness of the combined usage for further understanding water circulation of other various temperatures of metamorphic geothermalfields.

Electromagnetic self-encapsulation of carbon fiber reinforced Al matrix composite phase change material for high-temperature thermal energy storage

Realizing the effective encapsulation of eutectic Al-Si melt is of paramount significance for developing the Al matrix phase change materials in the high-temperature heat storage field. In this paper, a carbon fiber reinforced Al matrix composite phase change material with a Si-rich◎Si-poor cladding structure ([Cf×Si-rich]◎EAl-Si cPCM) was prepared by controlling the precipitation behavior of primary Si under electromagnetic stirring, which can realize the self-encapsulation of eutectic Al-Si alloy. The thermal and structural properties in steady state and non-steady state of the [Cf×Si-rich]◎EAl-Si cPCMs were systematically investigated. The results show that the [Cf×Si-rich] shell has a high thermal conductivity of 53.3–100.7 W/m·K at 200 °C~500 °C. With the increase of Si content in initial Al-Si melt, the high-temperature damage tolerance of the [Cf×Si-rich]◎EAl-Si40 cPCM prepared by Al-40Si is 62.8% higher than that of the [Cf×Si-rich]◎EAl-Si25 cPCM prepared by Al-25Si, but the heat storage capacity is decreased by 22.7%. The [Cf×Si-rich]◎EAl-Si30 cPCM prepared by Al-30Si melt is considered to have the best comprehensive property. Under the non-steady working condition, the [Cf×Si-rich]◎EAl-Si30 cPCM exhibited excellent structural stability and great phase change characteristics (0.3% fluctuation of the melting latent heat and 1.4% fluctuation of the phase change temperature). This work offers new self-encapsulation strategy for extending the application process of Al matrix PCM to the field of high-temperature thermal energy storage.

Energy of low-temperature plasma in the processes of thermal conversions of carbon-containing medium

One alternative for solving negative environmental impact is to use alternative renewable energy sources. However, technology is evolving and nowadays it cannot meet the needs of emerging economies. A promising direction in the field of clean technologies is the preliminary preparation of carbon-containing media of various origins by thermoconverting them into a gaseous state in high temperature fields. The analysis of the existing autothermal and allottermic technologies of gasification of carbonaceous media is given in the work. The advantages of allottermic technologies of high-temperature transformations under the action of arc plasma with steam oxidizing medium are presented. This method includes plasma formation processes, which combine in time and space thermal transformations and the generation of oxidant from water. The results of theoretical studies of the carbon-containing media plasma transformation process is presented in the article. The regularities of the temperature of steam-plasma transformation process influence on the qualitative and quantitative indicators of the obtained gas phase taking into account the medium elemental composition are established. Comparison of the cost indicators of production of synthetic motor fuel from natural gas by the known companies and from coal by steam-plasma conversion to gas is carried out.

Parametric dependence of collisional heating of highly magnetized over-dense plasma by (far-)infrared lasers

Abstract Heating of over-dense plasma represents a long-standing quest in laser–plasma physics. When the strength of the magnetic field is above the critical value, a right-handed circularly polarized laser could propagate into and heat up the highly magnetized over-dense collisional plasma directly; the processes are dependent on the parameters of the laser, plasma and magnetic field. The parametric dependence is fully studied both qualitatively and quantitatively, resulting in scaling laws of the plasma temperature, heating depth and energy conversion efficiency. Such heating is also studied with the most powerful CO2 and strongest magnetic field in the world, where plasma with density of ${10}^{23}$ cm–3 and initial temperature of 1 keV is heated to around 10 keV within a depth of several micrometres. Several novel phenomena are also discovered and discussed, that is, local heating in the region of high density, low temperature or weak magnetic field.

Determination of the Cement Sheath Interface and the Causes of Failure in the Completion Stage of Gas Wells

The bonding quality of the cement sheath interface decreases during well completion because of the change in the casing pressure. To explore the root cause of such phenomena, experiments on the mechanical properties and interface bonding strength of a cement sheath have been carried out taking the LS25-1 high-temperature and high-pressure (HTHP) gas field as an example. Moreover, a constitutive model of the cement sheath has been defined and verified both by means of a full-scale HTHP cement sheath sealing integrity evaluation experiment and three-dimensional finite element simulations. The results show that the low initial cementing surface strength is the root cause of cement sheath interface bonding failure. When the pressure in the casing exceeds a certain limit, the stress caused by the change in the internal pressure in the casing is transmitted to the cement sheath, resulting in the degradation of the interface stiffness of the cement sheath. However, with an increase in the casing wall thickness, the stress transmission capacity decreases. Therefore, it is concluded that improving the interfacial cementing strength, appropriately increasing the casing wall thickness and increasing the initial stress of the cement sheath are the keys to ensuring the sealing integrity of the cement sheath in high-temperature and high-pressure gas wells.

ВРЕМЕННЫЕ ИМПУЛЬСЫ КАЙНОЗОЙСКОГО ЭКСПЛОЗИВНО-ФРЕАТИЧЕСКОГО ВУЛКАНИЗМА В ЮГО-ЗАПАДНОМ ПРИМОРЬЕ. КОРРЕЛЯЦИЯ ИЗОТОПНЫХ И ФИТОСТРАТИГРАФИЧЕСКИХ ДАТИРОВОК

The Cenozoic tephra deposits - products of explosive phreatic eruptions of maar volcanoes in the southwest of Primorye are studied. The deposits represent rhyolitic ash and pumice pyroclastic beds with a high terrigenous component, including tephroid pseudo-conglomerates. Isotopic dating of tephra beds established two time pulses of explosive volcanism: 30–34 Mya and 23–24 Mya. The first time pulse coincided with the beginning of the formation of marginal seas and continental coal basins. It corresponds to the most productive stage of coal accumulation, the burial of wood wastes and their coalification at a faster rate, and the development of a high-temperature geothermal field and can be compared with the well-known catastrophic eruption of Mount St. Helens in the U.S.A. The second time pulse of explosive volcanism had a regional character of manifestation. It is characterized by the formation of green tuff complexes on submarine elevations of the Sea of Japan as well as along the western and eastern coasts of Japan. Synchronously with the volcanic activity started the acceleration of the sinking rate of the Sea of Japan bottom in response to the active rising of asthenospheric diapirs. The established isotopic ages do not conform to the ages determined for fossil leaves and pollen from the deposits, which may reflect the climate-forming type of such an explosive process.

Temperature Distribution in the Field Coil of a 500-kW HTS AC Homopolar Motor

AC homopolar motors with high-temperature superconductors (HTSs) are considered to be a promising technology for high-power applications. With superconducting components being placed exclusively in nonrotating parts, a motor can reach high rotational speeds. However, the dynamic behavior of the system creates a nonnegligible magnetic ripple field, which generates heat and makes thermal management of the cryogenic system more challenging. In this article, we present a case study for the thermal behavior of a conduction-cooled high-temperature superconducting field coil assembly in a 500-kW asynchronous homopolar motor. The analysis focuses on the investigation of the magnetic ripple field and its impact on heat generation due to ac loss in the HTS field coil and eddy current loss in copper parts present in the assembly. Using electromagnetic and thermal finite-element models, we construct a detailed description of the thermal bus design, which considers different cooling scenarios and sizing of the conductive elements. Depending on the geometry of the thermal bus, we observe heat loads from ac losses of up to 0.4 W and eddy current losses in the copper elements of up to 1 W. These heat loads translate to temperature increases as high as 10 K. Techniques to reduce the temperature rise based on thermal bus redesign are presented, along with recommendations for the most promising cooling scenarios and optimal thermal bus geometry.

Vacancy-modified few-layered GaN crystal for novel high-temperature energy storage

Vacancy-modified few-layered GaN crystal as an advanced electrode for IL-based SC devices, which is applied to high-temperature energy storage field for the first time. And the device exhibits superior energy storage capability at 150 °C.