Seal Properties Research Articles

Seismic Imaging of Halokinetic Sequences and Structures With High‐Resolution, Dual‐Element Acquisition, and Processing: Applications to the Gassum Structure in Eastern Jutland, Denmark

AbstractUnderstanding the structural intricacies of subsurface halokinetic formations is crucial for various geological applications, including geological capture and storage (geological carbon storage (GCS)). This study focuses on the seismic imaging of the Gassum structure in eastern Jutland, Denmark, employing high‐resolution, dual‐element acquisition, and processing techniques. The investigation aims to unravel details in the evolution of the salt dome and its implications for GCS potential. High‐resolution seismic data processing and interpretation reveals a skewed dome structure with steeper flanks on the western and northern sides, characterized by faults and stratigraphic thinning. The asymmetric growth of the dome suggests uneven salt loading during its genesis, influencing local stress fields and structural development, with evidence of syn‐tectonic subsidence that produced salt welds. This is supported by the presence of stratigraphic wedges and an increased depth of imaged horizons within steeper flanks of the dome. A mild piercement of the salt into overlying sediments, onlapping features, and the presence of normal faults that originate from the dome apex and extend radially, all indicate a reactive piercement process in the salt pillow's development stage. This produced an extensional regime in overlying strata, inducing sequence thinning and graben structures. Analysis of reservoir and seal properties unveils adequate conditions for GCS, with a continuous reservoir and thick primary and secondary seals. However, the presence of faults intersecting these formations raises concerns regarding long‐term storage stability. Further investigations into reservoir porosity, migration paths, and volumetric analysis are warranted for conclusive GCS assessments.

Mechanical and diffusion property and multi-objective optimization of rubber seals exposed to high-pressure hydrogen gas.

As the critical components in hydrogen refueling, storage, and transportation systems, the degradation and failure of rubber O-ring seals under a high-pressure (HP) hydrogen environment (up to 100 MPa) directly affect hydrogen energy safety. Clarifying the interaction mechanism of hydrogen diffusion and the mechanical properties of rubber seals is essential for HP hydrogen infrastructure. A hydrogen diffusion-mechanical sequential numerical model is built to investigate the sealing performance and hydrogen diffusion behaviors of rubber seals using ABAQUS software. The effects of hydrogen swelling environmental pressure (5∼100 MPa) and stress-concentration gradient on mechanical and contact characteristics and hydrogen concentration distribution are analyzed for the rubber seals with/without backup rings, respectively. Furthermore, the orthogonal experimental and comprehensive frequency analysis methods are employed to evaluate the significance of the main structural and assembly parameters and obtain the optimal schemes of the rubber seals under the HP environment. The results show that the stress concentration and rubber extrusion easily occur at the sealing clearance of the O-rings with swelling after pre-compression and pressurization. The hydrogen diffusion of the O-ring is mainly driven by the concentration difference and stress gradient, with the former being the dominant factor. With the increase in the hydrogen pressure, the effective sealing rate along the sealing surface decreases sharply, and the non-uniformity of hydrogen concentration and the possibility of fatigue damage in the rubber O-rings increase. Two multi-objective optimization schemes (Ⅰ and Ⅱ) for the main structural and assembly parameters of rubber seals are obtained by intuitive analysis and comprehensive frequency analysis to improve the extrusion tendency and sealing reliability of rubber seals in the HP hydrogen environment.

The Change of Sealing Property in the Aging Process of NBR Sealing Equipment Based on Finite Element Analysis

Sealing rings are the core components of flange sealing structures and play a crucial role in the storage and operation of gas generators. The aging and deformation of seals affect the safe operation of the device. This paper aims to investigate the effect of rubber aging on the sealing performance of the components, which is realized by nonlinear finite element analysis. Firstly, an accelerated degradation test method was used to obtain the compression permanent deformation and stress–strain curve of rubber during the aging process. A two-dimensional finite element model of the sealing structure was constructed and the Yeoh model was utilized to describe the mechanical response of rubber. During the simulation, the contact area was modified based on the compression permanent deformation, and the Yeoh model was updated based on the stress–strain curve changes obtained by the test. The impact of key parameters such as material property changes, rubber physical section deformation, and fluid pressure on sealing performance during the seal ring aging process was systematically studied. The numerical results indicate that due to the aging deformation of rubber seals, there is a significant decrease in contact stress and contact width, as well as a shift in maximum equivalent stress area. Taking into account these findings, this study proposes a new design concept for sealing structures. This provides a relatively simple research method for studying flange sealing structure performance.

Development of a Biopolymer-Based Anti-Fog Coating with Sealing Properties for Applications in the Food Packaging Sector.

The quest for sustainable and functional food packaging materials has led researchers to explore biopolymers such as pullulan, which has emerged as a notable candidate for its excellent film-forming and anti-fogging properties. This study introduces an innovative anti-fog coating by combining pullulan with poly (acrylic acid sodium salt) to enhance the display of packaged food in high humidity environments without impairing the sealing performance of the packaging material-two critical factors in preserving food quality and consumers' acceptance. The research focused on varying the ratios of pullulan to poly (acrylic acid sodium salt) and investigating the performance of this formulation as an anti-fog coating on bioriented polypropylene (BOPP). Contact angle analysis showed a significant improvement in BOPP wettability after coating deposition, with water contact angle values ranging from ~60° to ~17° for formulations consisting only of poly (acrylic acid sodium salt) (P0) or pullulan (P100), respectively. Furthermore, seal strength evaluations demonstrated acceptable performance, with the optimal formulation (P50) achieving the highest sealing force (~2.7 N/2.5 cm) at higher temperatures (130 °C). These results highlight the exceptional potential of a pullulan-based coating as an alternative to conventional packaging materials, significantly enhancing anti-fogging performance.

The guide-aggregation effect of microgrooves on tribological properties of mechanical seals

The guide-aggregation effect of microgrooves on tribological properties of mechanical seals

Advancement of an Environmentally Friendly and Innovative Sustainable Rubber Wrap Film with Superior Sealing Properties.

Common kitchen wraps like plastic and aluminum foil create significant environmental burdens. Plastic wrap, typically made from non-renewable fossil fuels, often ends up in landfills for centuries, breaking down into harmful microplastics. Aluminum foil, while effective, requires a large amount of energy to produce, and recycling it at home can be impractical due to food residue. A promising new alternative, low-nitrosamine rubber wrap film, aims to reduce waste by offering a reusable option compared to traditional single-use plastic wrap. The film is environmentally friendly, durable, and effective in sealing containers and keeping food fresh or crispy. The raw materials used to make the product were studied, namely fresh and concentrated natural rubber latex. No nitrosamines were found in either the fresh or concentrated latex, which is important as nitrosamines are known to be carcinogenic. The absence of nitrosamines in the raw materials suggests that the universal rubber wrap film is safe for use. In this study, the rubber formulation and properties of rubber used to make rubber wrap film were studied. The content of additives affecting the rubber properties was varied to find the optimum rubber formulation for making rubber wrap films. The rubber formulation with the least amount of chemicals that met the following criteria was selected: tensile strength of at least 15 MPa, elongation at break of at least 600%, and nitrosamine content below 6 ppm. It was found experimentally that the optimum rubber formulation for making a translucent rubber film had 0.7 phr zinc oxide and 1.0 phr sulfur. Performance tests revealed the rubber wrap film's superior sealing capabilities. Its elasticity allows for a tighter fit on containers, effectively conforming to various shapes and creating an optimal seal compared to plastic wrap and aluminum foil. The results of this study provide valuable information for developing a universal rubber wrap film that is safe with low nitrosamines.

Building a carbon storage portfolio for the Barrow and Dampier sub-basins – a national resource

The Australian government has recently legislated a 43% emissions reduction target for 2030 to drive net zero ambitions for 2050. The government plans for carbon capture and storage (CCS) to play a significant role in achieving this through greenhouse gas storage licence rounds. Rapid screening of Australia’s carbon storage opportunities is necessary to position future acreage release and ultimately identify and mature carbon storage sites. An industry collaboration between Geoscience Australia and SLB has conducted a basin-scale carbon storage assessment project for the Barrow and Dampier sub-basins. The project has built and modernised a subsurface database fit for CCS screening. The dataset was used as the foundation to create a carbon storage opportunity portfolio and storage resource assessment for the area. The project has three major streams: (1) CCS-focussed reprocessing, depth imaging and merging of 29 legacy seismic surveys covering 26,150 km2 – focussed on detailed image resolution for containment analysis. (2) A basin-wide audit of 1620 wells and databasing of available log data, 129 wells were carried through for petrophysical and rock physics analysis relevant to CCS. (3) A portfolio of carbon storage opportunities and associated capacity assessment for the Barrow–Dampier including saline aquifers and depleted fields ranked on storage capacity, reservoir and seal properties and integrity. The results of this study will be released via the National Offshore Petroleum Information Management System as a public resource to expedite CCS implementation for the region.

Amphiphilic Janus Nanoparticles with Enhanced Sealing Properties as Follower Sealants

Amphiphilic Janus Nanoparticles with Enhanced Sealing Properties as Follower Sealants

Ni–Co spinel based oxide as new type of additive to glass seal for solid oxide fuel cells

Glass seals utilized in Solid Oxide Fuel Cells (SOFCs) can be subject to modification through the incorporation of oxide additives to bolster their mechanical strength. This research focuses on a novel class of additives, specifically protective coating materials designed for alloy interconnects. It is crucial to emphasize that the glass seal interfaces directly with the protective coating, bypassing direct contact with the alloy itself. The efficacy of this approach is exemplified through the utilization of Ni–Co spinel-based oxide, established as an effective protective substance for stainless steel interconnects. The introduction of a minute quantity of Ni–Co oxides does not induce alterations in the glass seal properties, encompassing phase structure, microstructure, thermal expansion coefficient (CTE), and softening behavior. The Ni–Co oxide additive serves to mitigate the glass devitrification tendency, leading to a substantial augmentation in shear strength at the seal-interconnect interface and a marked enhancement in sealing properties. The composite seal, enriched with 3.0 wt% Ni–Co oxide, showcases superior sealing performance, demonstrating exceptional stability throughout a rigorous 1200-h test. The average leakage rate during this test period stands at 0.0024 sccm⋅cm−1. The incorporation of Ni–Co oxide triggers the formation of needle-shaped crystals, playing a pivotal role in averting channel void formation and augmenting the bonding strength between the seal and interconnect. Consequently, this fortifies gas tightness, ensuring the maintenance of outstanding sealing performance over an extended duration.

Mechanical, Rheological, and Heat Seal Properties of 1‐Octene Grafted Low Density Polyethylene Films

AbstractHeat seal and mechanical properties of 1‐octene grafted low density polyethylene films containing various concentrations of Dicumyl peroxide as the initiator and 1‐octene grafting agent is investigated through using experimental measurements. The results of differential scanning calorimeter (DSC) measurements revealed that the melting temperature shifts to higher values and the peak of the DSC curve becomes wider with the increase of 1‐octene concentrations. Thermogravimetric analysis (TGA) revealed a higher thermal stability up to 20 °C for 1‐octene grafted PE compared with neat LDPE alloy. The results of stress–strain measurements revealed that the 1‐octene grafted PE alloys has higher tensile strength in comparison with neat PE alloy and samples containing only DCP initiator. The results of heat seal analysis indicated that both DCP initiator and 1‐octene tended to offer a moderate increase peel strength of PE alloy. DMTA measurements for various grafted PE alloys show a higher damping factor in comparison with neat LDPE alloy. Rheological measurements indicated a higher storage modulus up to 25% and higher complex viscosity for grafted PE samples containing 1‐octene comonomer.

Multi-objective optimization of surface texture shape in fluid mechanical face seals using mass-conserving cavitation boundary condition

Surface texture shape significantly influences the tribological and sealing properties of fluid mechanical face seals. Considering that it is a contradiction to simultaneously improve load capacity and reduce leakage, a numerical multi-objective optimization model is proposed herein to improve the load-carrying capacity while reducing the volume leakage rate via texture shape optimization. The mass-conserving cavitating boundary condition and the non-dominated sorting genetic algorithm II are employed for the optimization. The numerical results indicate that the optimal texture shape is spiral-like under the lowest volume leakage rate, which becomes an asymmetric flat-front chevron with increasing load-carrying capacity and volume leakage rate. The optimal shape outperforms four regular shapes (all obtained by multi-objective optimization) at different rotation speeds and sealing pressures. The cavitation within the optimal shape ensures zero leakage in fluid face seals. The comprehensive performance of the texture shape obtained by multi-objective optimization is superior to that obtained by single-objective optimization.

Multi-tracer approach to constrain groundwater flow and geochemical baseline assessments for CO2 sequestration in deep sedimentary basins

Geological storage of gases will be necessary in the push to net zero and the energy transition to reduce carbon emissions to atmosphere. These include CO2 geological storage in suitable sandstone reservoirs. Understanding groundwater flow, connectivity and hydrogeochemical processes in aquifer and storage systems is vital to prevent risk and protect important water resources, such as the Great Artesian Basin. Here, we provide a ‘tool-box’ of geochemical assessment methods to provide information on flow patterns through the basin's aquifers (changes in chemistry along flow path), stagnant versus flowing conditions (cosmogenic isotopes and noble gases), inter-aquifer connectivity and seal properties (major ions, Sr and stable isotopes), water quality (major ions and metals) and general assessments on residence times of groundwater (cosmogenic isotopes and noble gases). This information can be used with reservoir and groundwater models to inform on possible changes in the above-mentioned processes and serve as input parameters for CO2 injection impact modelling. We demonstrate the use and interpretation on an example of a potential CO2 storage geological sequestration site in the Surat Basin, part of the Great Artesian Basin, and the aquifers that overly the reservoir. The stable water isotopes are depleted compared to average rainfall and most likely indicate greater contributions from monsoonal rain events from the northern monsoonal troughs, where amount and rainout effects lead to the depletion rather than colder recharge climates. This is supported by the modern recharge temperatures from noble gases. Inter-aquifer mixing between the Precipice Sandstone reservoir and the Hutton Sandstone aquifer seems unlikely as the Sr isotope ratios are distinctly different suggesting that the Evergreen Formation is a seal in the locations sampled. Mixing, however, occurs on the edges of the basin, especially in the south-east and east where the Surat Basin transitions into the Clarence-Moreton Basin. Groundwater flow appears to be to the south in the Precipice Sandstone, with a component of flow east to the Clarence-Morton Basin. The cosmogenic isotopes and noble gases strongly indicate very long residence times of groundwater in the central south Precipice Sandstone around a proposed storage site. 14C values below analytical uncertainty, R36Cl ratios at secular equilibrium as well as high He concentrations and high 40Ar/36Ar ratios support the argument that groundwater flow in this area is extremely slow or groundwater is stagnant. The results of this study reflect the geological and hydrogeological complexities of sedimentary basins and that baseline studies, such as this one, are paramount for management strategies.

Friction of fluoroplastic with steel in a hydraulic fluid medium when transient mode

The article considers the issues of experimental research of the antifriction properties of fluoroplastic seals of piston pump hydraulic systems in a transient friction mode. The statement about the influence of frictional heating on the tribological properties of the seal is substantiated. Model experiments are used to study the friction coefficients at the moment of changing the direction of the contacting surfaces movement and the transient period from the moment of starting from a standstill to the steadystate friction mode. The experiments were carried out under conditions of heating the hydraulic fluid to the maximum temperature. Particular attention is paid to the change in the friction coefficient with increasing load-speed characteristics. The limiting contact pressures that ensure trouble-free operation of a seal made of radiation-modified fluoroplastic have been determined.

Leakage performance of hybrid brush seals under high differential pressure conditions

A three-dimensional axial fluid-porous medium-flow field model was designed for the sealing properties of the hybrid brush seal (HBS) seal structure under complex operating conditions. Using a computational fluid dynamics model in view of non-Darcy porous media, the pressure and velocity distributions of the sealing medium in the flow path were simulated, and the flow characteristics of the hybrid brush seal were analysed to obtain the leakage of the hybrid seal structure. The results show the implication of pressure ratio (Rp) on the labyrinth brush seal leakage rate and pressure distribution. Compared with typical brush seal test results, as the inlet and outlet pressure ratio (Rp) increases, the more obvious the hybrid brush seal sealing effect is, when the pressure ratio is 3 bar, the spillage of the hybrid brush seal is reduced by about 39%.

Study on Microstructure and Sealing Property of Argillaceous Rock Cover in Underground Gas Storage

Study on Microstructure and Sealing Property of Argillaceous Rock Cover in Underground Gas Storage

Temperature Field and Performance Analysis of Brush Seals Based on FEA-CFD and the Porous Medium of Anisotropic Heat Transfer Models

A brush seal is a type of contact sealing technology that generates a great amount of heat during operations. The heat can affect the seal’s performance and lifespan. To study the brush seals’ temperature distribution, a new model considering the anisotropic heat transfer effect is established in this paper. The friction heat effect at the bristles’ tip is studied. The temperature field and leakage rates are obtained by using combined finite element analysis (FEA)-computational fluid dynamics (CFD) analysis and the anisotropic heat transfer theory. The influence of operating and structural parameters on the temperature field and the sealing properties of the brush seal are investigated. It is shown that the value of the rotation rate and the interference can cause the temperature of the brush seal to increase. The pressure difference enhances the convective heat transfer from the brush seals. While the temperature at the bristles’ tip increases, the radial average temperature of the bristles decreases significantly. In the case of a small pressure difference, the fence’s height can increase the windward area, leading to stiff bristles and resulting in a temperature increase at the bristles’ tip; however, the effective flow area increases, resulting in an acceleration of the radial temperature’s decrease. To summarize, the porous medium model of anisotropic heat transfer provides a new method for studying brush seals, and it can reflect the temperature distribution and leakage performance of brush seals.

Experimental Study on Friction and Wear Characteristics of Hydraulic Reciprocating Rotary Seals

Wear is one of the main failure causes of hydraulic seals. Wear will lead to degradation in the mechanical properties and sealing properties of seals. Compared with hydraulic seals with one-way rotational motion, the hydraulic reciprocating rotary seals work in more complex operating conditions, so their wear mechanism becomes more complicated. Aimed at exploring the friction and wear law of hydraulic reciprocating rotary seals and the property evolution law during the wear process, this paper set up an experimental system to simulate the working conditions of the hydraulic reciprocating rotary seals. The friction characteristics were obtained under different working pressures and different motion parameters. The wear characteristics were obtained under rated working conditions. The surface morphology was observed by SEM and the wear mechanism was analyzed.

Comparison of asphalt emulsion-based chip seal and hot rubber asphalt-based chip seal

The use of asphalt emulsion chip seal and hot rubber chip seal as pavement preservation techniques has been gaining popularity. This study aims to compare the laboratory performance of asphalt emulsion and hot rubber asphalt used in chip seal applications. Interlayer shear strength (ISS) and interlayer tensile strength (ITS) tests were designed to evaluate the bond quality of the chip seal samples prepared for both materials. The sweep test was used to estimate the aggregate loss of the chip seal on the asphalt pavement. The universal testing machines were used to evaluate the deterioration of the ISS and ITS values under cyclic load conditions, while the tensile and shear bond properties of chip seals under wet-freeze conditions were evaluated using freeze-thaw cycles. Results showed while both materials experienced a decline in their ISS and ITS values following repeated cycles of load and freeze-thaw, the hot rubber chip seal demonstrated significantly higher ISS and ITS values than the asphalt emulsion chip seal (48–111% and 36–102%, respectively). Moreover, the hot rubber chip seal exhibited better performance in terms of aggregate retention and cohesive strength. The aggregate gradation would affect the aggregate retention and cohesive strength. Nonetheless, both treatments are deemed acceptable for pavement maintenance. The weak bond between hot rubber asphalt or asphalt emulsion and aggregate could be attributed to cyclic load and freeze-thaw conditions.

Prediction of oil and gas occurrence in the Vilyui hemisineclise according to interpretation of geological and geophysical data and basin modeling (Republic of Sakha (Yakutia))

The paper is aimed at the prediction of oil and gas occurrence of the Upper Permian, Lower Triassic and Lower Jurassic deposits in the Vilyui hemisineclise. The basin modeling research implies the Upper Paleozoic and Mesozoic petroleum system model of the Vilyui hemisineclise. The initial generation time at the bottom of the Permian source rock is 270 Ma. The most intense generation of hydrocarbons is found to be in the late Permian and early Triassic. The generation power of the Permian source rock is 800 trillion m3. The hydrocarbon losses is up to 90% in consequence of unfavorable seal properties of the Lower Triassic and Lower Jurassic clay formations. All the potential hydrocarbon traps of the Vilyui hemisyneclise are considered to be formed during the Cretaceous stage of development. There is therefore an appropriate environment for the hydrocarbon accumulation to be in progress. The interpretation of geological and geophysical data identifies the areal extent prediction of sand reservoirs and overlying clay interlayers of high quality in the Upper Permian and Lower Triassic seals. The goal of a comprehensive approach to the sedimentary basin research is to divide the territory into oil and gas zones of various prospects in relation to the factors controlling hydrocarbon deposits.

Geological risk and uncertainty for underground storage of buoyant fluids, lessons learned in Illinois

Abstract This paper describes selected natural gas storage and carbon capture and storage (CCS) case studies from Illinois, USA, their general applicability to subsurface buoyant fluid storage, and summarizes lessons learned. In Illinois, a 70-year history of sustained natural gas storage has provided a foundational understanding of risk associated with using the subsurface for storing buoyant fluids. In addition to natural gas storage, over 3 million tonnes of CO 2 have been injected into the Cambrian Mt Simon Sandstone at the Decatur, IL CCS project site. In Illinois, many of the storage projects are in the Mt Simon Sandstone, a saline (aquifer) reservoir. In gas storage fields the characterization of faulting and seal properties has historically not been adequate. Identification of Precambrian palaeotopography is essential when completing initial site assessment in reservoirs close to the Precambrian contact. The presence of basement palaeotopographical highs increases the risk of not having a storage reservoir and increased chance of induced seismicity. The Cambrian Mt Simon Sandstone of the Illinois Basin has some of the most suitable strata in the midwestern USA for the sequestration of CO 2 and storage of energy in the form of natural gas. The improved understanding gained from natural gas storage and from carbon sequestration is also directly applicable to assessing the potential of emerging energy storage technologies, such as compressed air energy storage (CAES) and geological hydrogen storage.