Large-volume Reservoir Research Articles

Self-sealing mafic sills for carbon and hydrogen storage

AbstractTabular igneous intrusions (sills) are common features in sedimentary basins and have the potential to be useful seals for fluids (e.g. CO2or H2) in geological storage scenarios, and may be important as the need for geological carbon sequestration and alternative fuel storage increases. This is advantageous in regions without ready access to large-volume reservoirs in depleted hydrocarbon plays and saline aquifers, such as the northeastern USA. Moreover, geological H2storage requires more demanding conditions than those typically associated with oil and gas. An enhanced seal will have the properties of a traditional seal – competent, low permeability and laterally extensive – with the addition of being able to self-seal pre-existing and induced fractures. Self-sealing will occur along fluid pathways like fractures where CO2, water and minerals like plagioclase, olivine and pyroxene react together. Dolerite sills from the Gettysburg Basin, Pennsylvania, have remarkably low permeability and homogeneous compositions that include minerals that will readily react with CO2dissolved in water. Here, we characterize the physical properties and chemical gradients within several mafic sills cored in five boreholes. In addition, preliminary CO2-reaction experiments on dolerite samples demonstrated rapid carbonate mineralization.

Management of suction cup induced palatal bone resorption in xerostomia patient with sunken cheek appearance: A therapeutic and esthetic treatment option- A case report

Salivary reservoir in maxillary denture offers an effective, non-invasive approach in the treatment of edentulous patients afflicted with xerostomia. It is always desirable to have large volume reservoir in order to decrease the inconvenience of repeated refilling, however, increased bulk of palatal reservoir often leads to discomfort in speech, swallowing and acceptance of such prosthesis. In designing of size and shape of reservoir in the present case, large volume was achieved utilizing circular palatal resorption area, and proper shape was ensured by duplication of functional palatal contour. Adequate voluntary wetting of mouth was effected by “swallowing control saliva release” mechanism of the flexible reservoir lid. Sunken cheek appearance was addressed by using an easy, economical, and effective method of detachable cheek plumpers.

The positive effect of 3D interpenetrating network porous structure by carbon membranes on alleviating the volume expansion of SnS2 nanosheets for enhancing lithium and sodium storage

Transition-metal sulfide is one of the most promising anode candidates for lithium/sodium-ion batteries, but the extreme volume expansion leads to serious capacity decay during long-term cycling which limits its large-scale application. Herein, we designed a simple hydrothermal synthesis method combined with a membrane technology to fabricate flower-like SnS2 nanosheets uniformly anchored in the pores of the carbon membrane. The unique design demonstrated that an abundant membrane pore space was provided by the membrane technology for uniform growth of SnS2 nanosheet via a CS covalent bond. Meanwhile, the membrane pores and pore walls effectively relieved the volume expansion of SnS2 nanosheets during the charge/discharge process. Further, the even interpenetrating network structure of carbon membrane conductive scaffolds ensured its flexibility and structural integrity as anodes, which can provide plentiful charge transfer channels and large volume reservoirs for ion transmission. When the resulting composites were served as anodes, it achieved prominent electrochemical properties. The maximum reversible capacitance is 808.9 mA h g−1 for LIBs and 570.4 mA h g−1 for SIBs at 50 mA g−1, and outstanding rate capability was still maintained [333.3 mA h g−1 (LIBs) and 257.1 mA h g−1 (SIBs)] even at 2000 mA g−1. Moreover, almost no capacity loss was detected after the first few cycles during long-term cycles, fully suggesting that the membrane pores powerfully alleviated the volume expansion of SnS2 nanosheets and improved the cycle stability. Considering the positive effects of the unique porous structure provided by membrane technology on the electrochemical performance of the hybrid, the study offers an effective, simple, and low-cost strategy for large-scale production of SnS2-based anodes for the battery.

The multiple depleted mantle components in the Hawaiian-Emperor chain

Oceanic island basalts are targeted for geochemical study because they provide a direct window into mantle composition and a wealth of information on the dynamics and timescales associated with Earth mixing. Previous studies mainly focused on the shield volcanic stage of oceanic islands and the more fusible, enriched mantle components that are easily distinguished in those basalts. Mantle depleted compositions are typically more difficult to resolve unless large amounts of this material participated in mantle melting (e.g., mid-ocean ridges), or unique processes allow for their compositions to be erupted undiluted, such as very small degrees of melting of a source with minimal fusible enriched components (e.g., rejuvenated basalts) or as xenoliths (e.g., abyssal peridotites). Mantle depleted components, defined here as material with low time-integrated Rb/Sr (low 87Sr/86Sr) and high time-integrated Sm/Nd and Lu/Hf ratios (high 143Nd/144Nd and 176Hf/177Hf) relative to primitive mantle, derive from a potentially very large volume reservoir (up to 80% of the mantle), and therefore need adequate characterization in order estimate the composition of the Earth and mantle-derived melts. This review focuses on mantle depleted compositions in oceanic island basalts using the Hawaiian-Emperor chain as a case study. The Hawaiian-Emperor chain is the ∼6000km long geological record of the deeply sourced Hawaiian mantle plume, active for >81 Myr. Hawaiian volcanism evolves through four volcanic stages as a volcano traverses the Hawaiian plume: alkalic preshield, tholeiitic shield (80–90% volcano volume), alkalic postshield (∼1%), and silica undersaturated rejuvenated (<0.1%). We report Pb-Sr-Nd-Hf isotope compositions and trace element concentrations of three rejuvenated Northwest Hawaiian Ridge basalts and compare them to an exhaustive compiled dataset of basalts from the Hawaiian Islands to the Emperor Seamounts. The Northwest Hawaiian Ridge (NWHR) includes 51 volcanoes spanning ∼42m.y. between the bend in the Hawaiian-Emperor chain and the Hawaiian Islands where there is no high-precision isotopic data published on the rejuvenated-stage over ∼47% of the chain. NWHR and Hawaiian Island rejuvenated basalts are geochemically similar, indicating a consistent source for rejuvenated volcanism over ∼12.5 million years. In contrast, shield-stage basalts from the oldest Emperor Seamounts are more depleted in isotopic composition (i.e., higher 176Hf/177Hf, and 143Nd/144Nd with lower 87Sr/86Sr and 208Pb*/206Pb*) and trace element concentrations (i.e., much lower concentrations of highly incompatible elements) than all other depleted Hawaiian basalts younger than the bend, including NWHR rejuvenated basalts. The strongly depleted source for the oldest Emperor Seamounts (>70 Ma) was likely related to interaction with the Kula-Pacific-Izanagi mid-ocean ridge spreading system active near the Hawaiian plume in the Late Cretaceous. In contrast, the incompatible trace element ratios of NWHR rejuvenated basalts require a distinct source in the Hawaiian mantle plume that was imprinted by ancient (>1 Ga) partial melting, likely ancient recycled oceanic lithosphere. This review of the geochemistry of Hawaiian depleted components documents the need for the sampling of multiple distinctive depleted compositions, each preferentially melted during specific periods of Hawaiian plume activity. This suggests that the composition of depleted components can evolve during the lifetime of the mantle plume, as observed for enriched components in the Hawaiian mantle plume. Changes in the composition of depleted components are dominantly controlled by the upper mantle tectonic configurations at the time of eruption (i.e., proximity to a mid-ocean ridge), as this effect overwhelms the signal imparted by potentially sampling different lower mantle components through time.

WELL LOG DATA INTERPRETATION PROBLEMS IN WELL, DRILLED USING POLYMER-CLAY-BASED DRILLING MUD

There was shown the low efficiency of standard well logging sequence for reservoirs identification and de-fining their saturation in the well, penetrating on polymer-clay-based drilling mud the section with high salinity of formation water. At low resistances of formations the reliable results of testing as for large volume reservoirs as well as for small volume reservoirs are needed for establishing the critical values of indications of induction method and electrical measurements against the permeable formations of different thickness. To distinguish the reservoirs it is necessary to obtain the core samples and to analyze them to establish the compliance of indications between geophysical measurements and reservoir characteristics.

Modeling hydrothermal, suspended solids transport and residence time in a deep reservoir

This article presents the modeling of hydrothermal characteristics and suspended solids in a long and large-volume reservoir with a highly fluctuating water level. A laterally averaged two-dimensional hydrothermal and water quality model was configured for the Shihmen Reservoir in northern Taiwan. The model was validated with measured data of water surface elevation, water temperature, and concentration of suspended solids in 2006. The results show that the numerical model was able to reproduce the measured data. The validated model was then used to investigate the effects of water withdrawal schemes at different depths and to estimate the residence time in the reservoir. When water is withdrawn from a great depth, the relatively warm water from the upper layers can replace that in the deep layers, thereby facilitating heat transfer from the surface to the deeper layer. Bottom-water withdrawal results in a lower concentration of suspended solids compared with withdrawal from depths of 20 and 40 m. The simulated results show that the residence time is approximately 154 days in the Shihmen Reservoir.

Development of the one-step DRIE dry process for unconstrained fabrication of released MEMS devices

Current technologies allow the manufacture of released devices using deep reactive ion etching (DRIE) and SOI wafers, provided the device movement is not required to be more than a few microns (1–10 µm) Here, we describe the ‘waffle technique’, which will allow large areas surrounding a device to be cleared, therefore opening up opportunities for the design of devices with large movement capabilities (limited by the device's own actuation) or large volume reservoirs for micro fluidic applications. It should be noted that all DRIE etching in this work was carried out using a Surface Technology Systems DRIE which uses a process developed from the Bosch process (R B Bosch Gmbh 1994 US Patent Specification 4855017 and German Patent Specification 4241045CI) termed ‘time multiplexed deep etching’ (TMDE).

Combination of flow injection with capillary electrophoresis: Part 7. Microchip capillary electrophoresis system with flow injection sample introduction and amperometric detection

A microchip-based capillary electrophoresis (CE) system with amperometric detection, combined with flow injection (FI) sample introduction, was constructed from components readily available in the analytical laboratory. An H-channel configuration was used with separation capillary positioned between two tubular side-arms, and a falling-drop interface connected to one side-arm was developed to achieve electrical isolation between the FI and CE systems. End-column amperometric detection was accomplished with separation voltage decoupled from the detection system, employing a microdisk working electrode positioned immediately outside the capillary outlet in the other side-arm, which functioned as a large-volume reservoir. Sample dispersion in the FI system and the FI–CE interface was minimized by intercalating the sample zone between two air segments. Performance of the FI–CE amperometric system was demonstrated by separation of sugars. Separation of sucrose and glucose was performed with a 5 cm, 25 μm i.d. capillary with 1.7 kV separation voltage in about 60 s (40 μm plate height for glucose), achieving a sampling frequency of over 65 h −1. Responses for sucrose and glucose were linear in the range of 10–1000 μM with sensitivities of 0.011 and 0.025 nA μM −1. Detection limits ( S/ N=3) were 2 μM for sucrose and 1 μM for glucose. Peak height precisions were 2.1 and 2.4% R.S.D. ( n=9) for sucrose and glucose, respectively.

Evidence for the reversal of gradients in the uppermost parts of silicic magma reservoirs

Evidence from large-volume ignimbrites indicates that the source-magma reservoirs for most of these voluminous silicic pyroclastic deposits contained monotonic vertical chemical gradients at the time of eruption. However, gradients from a large-volume magma reservoir that produced a group of penecontemporaneous silicic lava domes, but no ignimbrite, show a reversal of the usual ignimbrite pattern. This reversal originated by modification of the usual pattern through minor assimilation of partially melted roof rocks. Eruptions that produced these domes apparently just tapped the uppermost part of their source reservoir. They thereby provide a high-resolution instantaneous view of this variably contaminated part of the magma system. Although not yet reported in the literature, similar reversals should be recorded in other groups of penecontemporaneous silicic domes and perhaps also in the lowermost parts of ignimbrites or in their underlying coeruptive Plinian deposits. The long-standing paradigm for monotonic zoning in large-volume reservoirs of silicic magma may require modification.

Efficiency of manual resuscitators at birth.

The effectiveness of five neonatal/paediatric manual resuscitators was assessed in a group of babies born by caesarean section. Results showed that devices incorporating a large volume reservoir produced the greatest tidal volume, while those with smaller volume reservoirs could not be considered satisfactory for routine use during neonatal resuscitation.