Viscosity Of Sealant Research Articles

Exploring epoxy resin sealants for sustained casing pressure mitigation in the wellbore

A significant challenge is sustained casing pressure(SCP) during oil and gas production. This study investigated a solid-free epoxy resin sealant to replace Portland cement. Properties such as sealant viscosity, curing time, compressive strength, and tensile strength were investigated. The sealing and fatigue resistance of cement and epoxy resin were compared. The results indicated that the curing time of epoxy resin was controlled at 3.1 ∼ 10.4 h. Adding a 25% viscosity reducer reduced the epoxy resin's viscosity by 97.63%. Remarkably, the epoxy resin surpassed cement in compressive strength, tensile strength, and elongation at break. The breakthrough pressure of the epoxy resin was higher than that of cement, and this advantage was more evident as the length increased. The convergence time of 10 mm epoxy was prolonged by 189.01% over that of cement. The epoxy resin effectively suppressed the rate of pressure increase after gas breakthrough. Under cyclic loading of 20% to 80% breakthrough pressure, the cement seal failed after 12 cycles, while the epoxy maintained seal integrity for 17 processes. The fatigue resistance of epoxy resin was superior to that of cement, ensuring long-term annulus sealing under alternating load perturbations. Epoxy resin sealant can potentially provide a new solution to the SCP problem.

The Effect of Preheating on Fissure Sealant Viscosity

The Effect of Preheating on Fissure Sealant Viscosity

Numerical Simulation of Aircraft Assembly Process with Presence of Sealant

<div class="section abstract"><div class="htmlview paragraph">Sealant is applied between joined aircraft parts in the final stage of the assembly, before installation of permanent fasteners. In this paper a novel approach for aircraft assembly simulation is suggested, which allows to resolve the transient interaction between parts and sealant in the course of airframe assembly process. The simulation incorporates such phenomena as compliance of parts, contact interaction between them and fluidity of sealant with presence of free surface. The approach based on fluid-structure interaction techniques consists of two basic steps: at the first one the pressure of sealant is found after corresponding fluid dynamics problem is solved and at the second the displacements of parts and sealant are calculated through the solving of contact problem. Iterations between structural and fluid dynamics solvers are performed to achieve convergence. The developed approach is demonstrated on example of joining of two test aircraft panels. The viscosity of sealant was selected based on available experimental data. The results of simulations show how such parameters as fastening force and sealant layer thickness affect the assembly process.</div></div>

Laboratory evaluation of short and long term performance of hot-poured sealants

Hot-poured sealants are commonly applied to repair cracks on asphalt pavements. However, existing methods of performance evaluation do not fully reflect the performance of hot-poured sealant for pavement application. Therefore, this article proposes different tests, melting point and melt flow index of packing films, sealant viscosity, segregation, thermal aging performance, and bond after water immersion, to specifically address identified problems and evaluate the short and long term performance of hot-poured sealant. A sealant performance ranking system was proposed based on the tests of nine sealants. The indicators of current performance evaluation, installation performance as well as thermal and immersion stability were weighted in this system. Different test results were classified and scored and then nine sealants were ranked quantitatively. The proposed system provides a more comprehensive evaluation of field performance of hot-poured sealant compared to existing performance evaluation methods, and correctly ranks the sealants in terms of their practical performance. Therefore, the proposed tests can be employed to complement current performance evaluation indicators.

Effects of sealant, viscosity, and bonding agents on microleakage of fissure sealants: An in vitro study.

Objective:The aim of this study was to evaluate the effects of enamel or dentin bonding agent (DBA) and sealant viscosity on sealant microleakage.Materials and Methods:Sixty extracted human premolars were randomly divided into two equal groups (based on sealant viscosity) and each group was divided into three subgroups of 10 teeth. Group 1 (low viscosity sealant, Seal-Rite, Pulpdent, USA with 7.7% filler): Prophylaxis, enameloplasty, etching of occlusal surfaces with 38% of phosphoric acid gel, rinsing and drying, followed by (1) enamel bonding agent (EBA) (Margin Bond, Coltène/Whaledent AG) or (2) DBA (Excite, Ivoclar Vivadent AG, Liechtenstein) or (3) no bonding (NB) prior to sealant application. In Group 2, similar procedures were performed except for applying a high viscosity sealant (Seal-Rite, Pulpdent, The USA with 34.4% filler). Specimens were thermocycled and then immersed in a 0.5% basic fuchsine solution for 24 h next, buccolingual slices of samples were scored under a stereomicroscope. The Kruskal–Wallis and Mann–Whitney U-tests were used for data analysis.Results:There was no significant difference between DBA, EBA, and NB subgroups in the microleakage scores in both groups. Low viscosity sealant had a lower microleakage than the high viscosity sealant in both DBA (P = 0.002) and NB (P = 0.041) subgroups.Conclusion:The results indicated that the use of low viscosity sealant reduced the microleakage of pit and fissure sealants. However, the use of a bonding agent before sealant placement didn’t affect the microleakage.

Effect of Bituminous Material Rheology on Adhesion

Bituminous materials are used in many civil engineering applications in which adhesion to a substrate is essential for good performance. Yet it is not possible to predict the adhesion of these materials. The particular case of bituminous crack sealants is of interest; the effect of sealant viscosity, aging, test temperature, and loading rates was investigated by means of a blister test. This test provided the bonding characteristics to a model aggregate in relation to interfacial fracture energy (IFE). From testing of several sealants, it was found that pouring viscosity affects adhesion and that higher viscosities help to attain higher IFEs. Temperature was found to play a key role on bonding characteristics and failure mechanism because it affected the viscoelastic properties of the sealant. The glass transition temperature (Tg) was found to have a governing role on bonding characteristics. At temperatures above Tg, bond strength was found to be affected by sealant flow such that failure was flow related; that is, cohesive failure prevailed. At temperatures below the Tg, at which sealants were stiff and bulk deformation was low, stress was directed toward the interface so that failure tended to be adhesive. In taking into account temperature and test rates, an IFE master curve was obtained for a sealant. Such a curve may be used in predicting and comparing sealant IFE.

Development of a Viscosity Specification for Hot-Poured Bituminous Sealants

Abstract Current crack sealant specifications focus on using simple empirical tests such as penetration, resilience, flow, and bonding to cement concrete briquettes (ASTM D 6690) [1] to measure the ability of the material to resist cohesive and adhesive failures. There is, however, no indication of the pertinence of these standard tests to predict the success of field installation and sealant performance. In an effort to bridge the gap between sealant fundamental properties and field performance, performance-based guidelines for the selection of hot-poured crack sealants are currently being developed. This paper proposes a new viscosity test procedure to help assess the propensity of sealants to wet the crack surface during installation. The proposed procedure calls for the use of a Brookfield rotational viscometer equipped with a modified spindle rod and an SC4-27 spindle at a speed of 60 r/min. Sealants are heated 20 min at the recommended installation temperature and the viscosity is measured after 30 s of spindle rotation in the hot sealant. These experimental conditions provide viscosities representative of sealant viscosity at shear rates during field application. The repeatability for within laboratory and between laboratories was found to be 5.4 and 17 %, respectively. This repeatability is comparable with the corresponding variability of the SuperPave viscosity test for asphalt binders.

Viscosity Determination of Hot-Poured Bituminous Sealants

Hot-poured bituminous sealants are typically selected on the basis of empirical standard tests such as penetration, resilience, flow, and bond to cement concrete briquettes (ASTM D3405). Yet there is no indication of the pertinence of these standard tests to predict field performance. To bridge the gap between sealant fundamental properties and field performance, performance-based guidelines for selection of hot-poured crack sealants are currently being developed. A procedure to measure sealant viscosity is proposed as part of that effort. Using a sealant with an appropriate consistency at the recommended installation temperature would provide a better crack filling and would ensure appropriate bond strength. Therefore, to ensure that sealant–crack wall adhesion is achieved and that the sealant penetrates hot-mix asphalt during installation, a testing procedure for bituminous-based crack sealant viscosity at installation temperature is suggested. This paper proposes use of a rotational viscometer to measure viscosity of hot-poured crack sealant materials. From results of this study, the measured viscosity of hot-poured crack sealant using a SC4-27 spindle at 60 rpm at the recommended installation temperature is reasonably representative of sealant viscosity at shear rates resembling field application. To ensure measurement consistency and stability, a 20-min melting time and 30-s waiting time before data collection are recommended. Repeatability of measurements was acceptable, with an average coefficient of variation of less than 5%. Variability between operators and variability between sealant samples were acceptable.