Manuscript Title: Characterization of Microannuli at the Cement-Casing Interface: Development of Methodology

2021 ◽  
Author(s):  
Adijat Ogienagbon ◽  
Mahmoud Khalifeh ◽  
Xinxiang Yang ◽  
Ergun Kuru
Keyword(s):  
Optical Microscopy ◽  
Direct Visualization ◽  
Current Trends ◽  
Well Integrity ◽  
Current Article ◽  
Experimental Findings ◽  
Geometric Variation ◽  
Non Destructive ◽  
Cement Plug

Abstract Formation of microannuli at the interface of cement-casing can create well integrity issues. X-ray CT and Optical microscopy are technological trends that may have potential for direct visualization of microannuli. CT has an advantage of providing non-destructive visualization of microannuli, but its resolution suffers with increase in casing thickness. Conversely, Optical microscopy has the potential of providing higher resolution needed to detect smaller sized microannuli; however, information about microannuli is limited to only a few sections where samples have been sliced. The objective of the current article is to describe a methodology to examine the interface of cement-casing. Experimental work was combined with literature review. This includes both direct visualization methods, evaluation of current trends to better understand the characteristics and geometric variation of relevant leakage paths. We generate test specimens consisting of cement plugs, various steel casing thickness and nano-coated aluminium casings. Hydraulic sealability tests were conducted by injecting water at the cement-casing interface. Flow rates are then interpreted in terms of microannuli aperture and direct visualization of the cement plug-casing interface by CT and Optical microscopy was implemented. The experimental findings of this article will form a basis for studying geometry and size of microannuli as well as modelling of fluid migration.

scholarly journals Characterization of medieval-like glass alteration layers by laser spectroscopy and nonlinear optical microscopy

2021 ◽  
Vol 136 (8) ◽  
Author(s):  
Mohamed Oujja ◽  
Teresa Palomar ◽  
Marina Martínez-Weinbaum ◽  
Sagrario Martínez-Ramírez ◽  
Marta Castillejo
Keyword(s):  
Optical Microscopy ◽  
Nonlinear Optical ◽  
Three Dimensional ◽  
Chemical Characterization ◽  
Conservation Strategies ◽  
Cross Sectional ◽  
Nonlinear Optical Microscopy ◽  
Non Destructive ◽  
Ft Raman

AbstractHistorical glass-based objects undergo, since the time of their manufacture, different degradation phenomena that are related to their composition and to the environment to which they were exposed. Three-dimensional (3D) structural and chemical characterization of the degradation layers is important to select the most adequate conservation strategies for glass objects. Optical microscopy (OM) is the most frequently used non-destructive method to examine the surface of historical glasses; however, the 3D structural assessment of alteration layers requires applying the destructive modality of this technique to conduct a cross-sectional study. In this work, a different approach for structural and compositional characterization of alteration layers on model medieval-like glasses is presented, based on the combination of the laser spectroscopies of laser-induced breakdown spectroscopy (LIBS), laser-induced fluorescence (LIF) and FT-Raman, and the emerging, cutting edge technique of nonlinear optical microscopy (NLOM) in the modality of multiphoton excitation fluorescence (MPEF). The results obtained through this multi-analytical photonic approach were compared with those retrieved by examination of the surface and cross sections of the samples by OM and scanning electron microscopy–energy-dispersive X-ray spectroscopy (SEM–EDS). While the combination of LIBS, LIF and FT-Raman served to assess the composition of the various alteration layers, the use of MPEF microscopy allowed the non-destructive determination of the thicknesses of these layers, showing for both thickness and composition a good agreement with the OM and SEM–EDS results. Thus, the proposed approach, which avoids sample preparation, illustrates the capability of non-destructive, or micro-destructive in the case of LIBS, laser spectroscopies and microscopies for the in situ study of glass objects of historic or/and artistic value. Graphic Abstract

Instrumental characterization of geological materials and their synthetic analogs

2015 ◽  
Vol 87 (3) ◽  
pp. 301-306 ◽  
Author(s):  
Enver Murad
Keyword(s):  
Optical Microscopy ◽  
Spectroscopic Techniques ◽  
Geological Samples ◽  
X Ray Diffraction ◽  
X Ray ◽  
Geological Materials ◽  
General Characterization ◽  
Mineral Characterization ◽  
Non Destructive

AbstractThe mineralogy of geological samples is generally determined by optical microscopy or X-ray diffraction. 57Fe Mössbauer and Raman spectroscopies are effective alternative non-destructive nuclear and vibrational instrumental techniques that can – in conjunction with the former procedures, and all the more when these fail – serve for mineral characterization. In favorable cases these spectroscopic techniques enable, beyond a mere general characterization, the conclusive identification of selected minerals.

scholarly journals Characterization of swelling behavior of carbon nano-filler modified polydimethylsiloxane composites

2021 ◽  
pp. 009524432110061
Author(s):  
Bo Yang ◽  
Balakrishnan Nagarajan ◽  
Pierre Mertiny
Keyword(s):  
Digital Image Analysis ◽  
Swelling Behavior ◽  
Optical Measurements ◽  
Natural Phenomenon ◽  
Cross Linking ◽  
Dimensional Changes ◽  
Experimental Findings ◽  
Carbon Based

Polymers may absorb fluids from their surroundings via the natural phenomenon of swelling. Dimensional changes due to swelling can affect the function of polymer components, such as in the case of seals, microfluidic components and electromechanical sensors. An understanding of the swelling behavior of polymers and means for controlling it can improve the design of polymer components, for example, for the previously mentioned applications. Carbon-based fillers have risen in popularity to be used for the property enhancement of resulting polymer composites. The present investigation focuses on the effects of three carbon-based nano-fillers (graphene nano-platelets, carbon black, and graphene nano-scrolls) on the dimensional changes of polydimethylsiloxane composites due to swelling when immersed in certain organic solvents. For this study, a facile and expedient methodology comprised of optical measurements in conjunction with digital image analysis was developed as the primary experimental technique to quantify swelling dimensional changes of the prepared composites. Other experimental techniques assessed polymer cross-linking densities and elastic mechanical properties of the various materials. The study revealed that the addition of certain carbon-based nano-fillers increased the overall swelling of the composites. The extent of swelling further depended on the organic solvent in which the composites were immersed in. Experimental findings are contrasted with published models for swelling prediction, and the role of filler morphology on swelling behavior is discussed.

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