scholarly journals AREAL SURFACE CHARACTERIZATION OF ACID-FRACTURES IN CARBONATE ROCKS

2012 ◽  
Vol 30 (2) ◽  
Author(s):  
Rodrigues Valdo Ferreira ◽  
Victor Rodolfo Araujo ◽  
Campos Wellington ◽  
Ana Catarina da Rocha Medeiros
Keyword(s):  
Hydraulic Conductivity ◽  
Surface Characterization ◽  
Oil And Gas ◽  
Fine Particles ◽  
Surface Characteristics ◽  
Abnormal Behavior ◽  
Fracture Conductivity ◽  
Surface Parameters ◽  
Fracture Width ◽  
3D Surface

Fracture surface characteristics have significant effect on fracture hydraulic conductivity. The available acid-fracture conductivity correlations do notconsider surface characteristics or make an incipient use of it. A proper description of the acid-fracture surfaces is the initial step towards the right consideration of surface roughness in hydraulic conductivity. This paper presents an areal (3D) surface evaluation of acid-etched fractures, simulated in samples taken from whole cores of an oil producer limestone. The topography of acid-fractured surfaces was assessed using a laser profilometer. The surfaces were evaluated with a set of 3D surface parameters. The results showed that the main features of acid-etched surfaces are large roughness, negative skewness, high kurtosis, and intermediate isotropy, mostly random, but with some spatial orientation. The acid-fractured surfaces can be represented by the rms height, which showed great linear correlation with most of the surface parameters. The parameters texture aspect ratio, bearing index, valley retention index, and density of summits showed low correlation with rms height. A method to calculate fracture width from surface topography was developed. An attempt to explain abnormal behavior in initial conductivity tests revealed the potential use of surface characterization for management of fine particles in oil and gas reservoirs. It is suggested to search improved fracture conductivity correlation through the relationship between lab measured conductivities and surface characterization parameters.

The Application of Three-Dimensional Surface Parameters to Characterizing Grinding Wheel Topography

2010 ◽  
Vol 126-128 ◽  
pp. 603-608
Author(s):  
Lan Yan ◽  
Zhi Xiong Zhou ◽  
Feng Jiang ◽  
Yi Ming Rong
Keyword(s):  
Surface Characterization ◽  
Grain Shape ◽  
Three Dimensional ◽  
Sampling Interval ◽  
Grinding Wheel ◽  
Optimal Sampling ◽  
Surface Parameters ◽  
3D Surface ◽  
Wheel Topography ◽  
Grinding Wheel Topography

White light interferometer was employed to measure the surface topography of 60# and 120# alumina grinding wheel. The correlation of wheel topography and its performance was characterized through the three-dimensional (3D) surface characterization parameters of “Birmingham set”. Birmingham parameters were used to characterize the performances of grinding wheel, in items of grain density, grain shape and grain sharpness. The effects of sampling interval on the 3D surface parameters were analyzed and the optimal sampling interval was selected to calculate the 3D surface parameters.

scholarly journals Post-Processing and Surface Characterization of Additively Manufactured Stainless Steel 316L Lattice: Implications for BioMedical Use

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1376
Author(s):  
Alex Quok An Teo ◽  
Lina Yan ◽  
Akshay Chaudhari ◽  
Gavin Kane O’Neill
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Surface Characterization ◽  
High Surface ◽  
Surface Characteristics ◽  
Post Processing ◽  
Stainless Steel 316L ◽  
Processing Methods ◽  
Particulate Debris

Additive manufacturing of stainless steel is becoming increasingly accessible, allowing for the customisation of structure and surface characteristics; there is little guidance for the post-processing of these metals. We carried out this study to ascertain the effects of various combinations of post-processing methods on the surface of an additively manufactured stainless steel 316L lattice. We also characterized the nature of residual surface particles found after these processes via energy-dispersive X-ray spectroscopy. Finally, we measured the surface roughness of the post-processing lattices via digital microscopy. The native lattices had a predictably high surface roughness from partially molten particles. Sandblasting effectively removed this but damaged the surface, introducing a peel-off layer, as well as leaving surface residue from the glass beads used. The addition of either abrasive polishing or electropolishing removed the peel-off layer but introduced other surface deficiencies making it more susceptible to corrosion. Finally, when electropolishing was performed after the above processes, there was a significant reduction in residual surface particles. The constitution of the particulate debris as well as the lattice surface roughness following each post-processing method varied, with potential implications for clinical use. The work provides a good base for future development of post-processing methods for additively manufactured stainless steel.

scholarly journals A systematic assessment of water vapor products in the Arctic: from instantaneous measurements to monthly means

2021 ◽  
Vol 14 (7) ◽  
pp. 4829-4856
Author(s):  
Susanne Crewell ◽  
Kerstin Ebell ◽  
Patrick Konjari ◽  
Mario Mech ◽  
Tatiana Nomokonova ◽  
...  
Keyword(s):  
Water Vapor ◽  
Surface Characterization ◽  
Surface Characteristics ◽  
The Arctic ◽  
Monthly Means ◽  
Atlantic Sector ◽  
Mean Values ◽  
Systematic Assessment ◽  
Retrieval Algorithms ◽  
Spatio Temporal

Abstract. Water vapor is an important component in the water and energy cycle of the Arctic. Especially in light of Arctic amplification, changes in water vapor are of high interest but are difficult to observe due to the data sparsity of the region. The ACLOUD/PASCAL campaigns performed in May/June 2017 in the Arctic North Atlantic sector offers the opportunity to investigate the quality of various satellite and reanalysis products. Compared to reference measurements at R/V Polarstern frozen into the ice (around 82∘ N, 10∘ E) and at Ny-Ålesund, the integrated water vapor (IWV) from Infrared Atmospheric Sounding Interferometer (IASI) L2PPFv6 shows the best performance among all satellite products. Using all radiosonde stations within the region indicates some differences that might relate to different radiosonde types used. Atmospheric river events can cause rapid IWV changes by more than a factor of 2 in the Arctic. Despite the relatively dense sampling by polar-orbiting satellites, daily means can deviate by up to 50 % due to strong spatio-temporal IWV variability. For monthly mean values, this weather-induced variability cancels out, but systematic differences dominate, which particularly appear over different surface types, e.g., ocean and sea ice. In the data-sparse central Arctic north of 84∘ N, strong differences of 30 % in IWV monthly means between satellite products occur in the month of June, which likely result from the difficulties in considering the complex and changing surface characteristics of the melting ice within the retrieval algorithms. There is hope that the detailed surface characterization performed as part of the recently finished Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) will foster the improvement of future retrieval algorithms.

scholarly journals Surface Characteristics of Seersucker Woven Fabrics

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Malgorzata Matusiak ◽  
Vladimir Bajzik
Keyword(s):  
Surface Roughness ◽  
Evaluation System ◽  
Surface Friction ◽  
Surface Characteristics ◽  
Measurement Procedure ◽  
Woven Fabrics ◽  
Point Of View ◽  
Woven Fabric ◽  
Weft Yarn ◽  
Surface Parameters

AbstractThe surface characteristics of fabrics are important from the point of view of the sensorial comfort of clothing users. Surface friction and surface roughness are the most important surface parameters of fabrics. These parameters can be measured using different methods, the most important and well-accepted method being that using the Kawabata evaluation system (KES)-FB4 testing instrument. In this work, the surface roughness and surface friction of the seersucker woven fabric have been determined using the KES-FB4. However, the measurement procedure needs modification. On the basis of the results, the influence of the repeat of the seersucker effect and the linear density of the weft yarn on the surface parameters has been determined.

scholarly journals OPTIMISATION OF HYDRAULIC FRACTURING DESIGN IN LOWER OLIGOCENE RESERVOIR, KINH NGU TRANG OILFIELD

2018 ◽  
Vol 18 (3) ◽  
pp. 323-337
Author(s):  
Nguyen Huu Truong
Keyword(s):  
Hydraulic Fracturing ◽  
Complex Structure ◽  
Power Requirement ◽  
Fracture Conductivity ◽  
Fracture Width ◽  
The North ◽  
Fracture Closure ◽  
Average Water ◽  
White Tiger ◽  
Fracture Height

Kinh Ngu Trang oilfield is of the block 09-2/09 offshore Vietnam, which is located in the Cuu Long basin, the distance from that field to Port of Vung Tau is around 140 km and it is about 14 km from the north of Rang Dong oilfield of the block 15.2, and around 50 km from the east of White Tiger in the block 09.1. That block accounts for total area of 992 km2 with the average water depth of around 50 m to 70 m. The characteristic of Oligocene E reservoir is tight oil in sandstone, very complicated with complex structure. Therefore, the big challenges in this reservoir are the low permeability and the low porosity of around 0.2 md to less than 1 md and 1% to less than 13%, respectively, leading to very low fracture conductivity among the fractures. Through the Minifrac test for reservoir with reservoir depth from 3,501 mMD to 3,525 mMD, the total leak-off coefficient and fracture closure pressure were determined as 0.005 ft/min0.5 and 9,100 psi, respectively. To create new fracture dimensions, hydraulic fracturing stimulation has been used to stimulate this reservoir, including proppant selection and fluid selection, pump power requirement. In this article, the authors present optimisation of hydraulic fracturing design using unified fracture design, the results show that optimum fracture dimensions include fracture half-length, fracture width and fracture height of 216 m, 0.34 inches and 31 m, respectively when using proppant mass of 150,000 lbs of 20/40 ISP Carbolite Ceramic proppant.

scholarly journals Evaluating the Effectiveness of Urban Hedges as Air Pollution Barriers: Importance of Sampling Method, Species Characteristics and Site Location

Environments ◽  
2020 ◽  
Vol 7 (10) ◽  
pp. 81
Author(s):  
Tijana Blanuša ◽  
Zeenat Jabeen Qadir ◽  
Amanpreet Kaur ◽  
James Hadley ◽  
Mark B. Gush
Keyword(s):  
Air Pollution ◽  
Fine Particles ◽  
Surface Characteristics ◽  
Cost Effective ◽  
Rapid Screening ◽  
Site Location ◽  
Particulate Air Pollution ◽  
Body Of Knowledge ◽  
Pollutant Concentrations ◽  
Species Characteristics

Urban hedgerows can act as barriers to roadside particulate air pollution, but details on methodologies to quantify pollutant capture, most efficient species to use, and practical planning advice are still evolving. We aimed to compare three widely used approaches to quantify particulate accumulation and deposition, and to ascertain the most cost-effective and robust approach for the rapid screening of various types of hedges. Secondly, using the most efficient methodology, we screened the summertime deposition of particulates on roadside hedges in Reading (UK), not just on species with differing leaf surface characteristics, but also along a transect of the hedge depth. Finally, we also compared particles’ capture by hedge leaf surfaces in locations with different traffic intensities, to try and ascertain the extent of reduction of particles’ concentration in various hedge types and urban locations. Results suggest that the gravimetric determination of particulate capture was most rapid and cost-effective, while being least technically demanding. We confirmed that hairy and more complex leaves captured most particulates, particularly in the >10 μm range. However, species choice only had a significant impact on the extent of capture on major roads, where the pollutant concentrations were highest. Furthermore, only hedge depths in excess of 2 m were found to noticeably reduce the concentration of fine particles in species with less capacity for particulates’ capture. Findings complement the growing body of knowledge to guide urban and landscape planners in choosing the most appropriate species to mitigate air quality in various urban contexts.

scholarly journals Estimating Unpropped-Fracture Conductivity and Fracture Compliance From Diagnostic Fracture-Injection Tests

SPE Journal ◽  
2018 ◽  
Vol 23 (05) ◽  
pp. 1648-1668 ◽  
Author(s):  
HanYi Wang ◽  
Mukul M. Sharma
Keyword(s):  
Earth Science ◽  
Mathematical Framework ◽  
Field Scale ◽  
Time Data ◽  
Fracture Conductivity ◽  
Reliable Technique ◽  
Fracture Width ◽  
In Situ Conditions ◽  
Fracture Closure

Summary A new method is proposed to estimate the compliance and conductivity of induced unpropped fractures as a function of the effective stress acting on the fracture from diagnostic-fracture-injection-test (DFIT) data. A hydraulic-fracture resistance to displacement and closure is described by its compliance (or stiffness). Fracture compliance is closely related to the elastic, failure, and hydraulic properties of the rock. Quantifying fracture compliance and fracture conductivity under in-situ conditions is crucial in many Earth-science and engineering applications but is very difficult to achieve. Even though laboratory experiments are used often to measure fracture compliance and conductivity, the measurement results are influenced strongly by how the fracture is created, the specific rock sample obtained, and the degree to which it is preserved. As such, the results may not be representative of field-scale fractures. During the past 2 decades, the DFIT has evolved into a commonly used and reliable technique to obtain in-situ stresses, fluid-leakoff parameters, and formation permeability. The pressure-decline response across the entire duration of a DFIT reflects the process of fracture closure and reservoir-flow capacity. As such, it is possible to use these data to quantify changes in fracture conductivity as a function of stress. In this paper, we present a single, coherent mathematical framework to accomplish this. We show how each factor affects the pressure-decline response, and the effects of previously overlooked coupled mechanisms are examined and discussed. Synthetic and field-case studies are presented to illustrate the method. Most importantly, a new specialized plot (normalized system-stiffness plot) is proposed, which not only provides clear evidence of the existence of a residual fracture width as a fracture is closing during a DFIT, but also allows us to estimate fracture-compliance (or stiffness) evolution, and infer unpropped fracture conductivity using only DFIT pressure and time data alone. It is recommended that the normalized system-stiffness plot (NS plot) be used as a standard practice to complement the G-function or square-root-of-time plot and log-log plot because it provides very valuable information on fracture-closure behavior and the properties of fracture-surface roughness at a field-scale, information that cannot be obtained by any other means.

CO2-saturated Salinity Environment Effects on Ni-Mo Alloys at Gas Hydrate Formation Temperatures

2019 ◽  
Author(s):  
Christopher Ozigagu ◽  
Ting Zhou ◽  
Stephen Sanders ◽  
Teresa Golden
Keyword(s):  
Corrosion Resistance ◽  
Deep Water ◽  
Gas Hydrate ◽  
Surface Characterization ◽  
Oil And Gas ◽  
High Salinity ◽  
Hydrate Formation ◽  
Test Solution ◽  
Low Salinity ◽  
Gas Hydrate Formation

Corrosion and gas hydrate formation are flow assurance problems that can cause serious safety problems in deep water environments. One aspect that has been given less attention is the corrosion behavior of materials in salinity environment where gas hydrate formation and CO2 (sweet) corrosion can both occur. This type of environment is common in oil and gas deep water environments. The aim of this work is to investigate the effects of CO2-saturated salinity environment on Ni-Mo alloys at gas hydrate formation temperatures using electrochemical, SEM/EDX, and XRD surface characterization techniques. The immersion test solutions were sweet low-salinity (CO2 + 1 wt% salt + 5 oC) and sweet high- salinity (CO2 + ~24 wt% salt + 5 oC) environments, respectively. The as-deposited Ni-Mo alloy coating has the highest corrosion resistance of 33.28 kΩ cm2. The corrosion resistance dropped to 14.36 kΩ cm2 and 11.11 kΩ cm2 after 20 hrs of immersion in the sweet low-salinity and sweet high-salinity test solutions respectively. From grazing incidence XRD, the (111) reflection peak of the Ni-Mo coating was depressed and broaden after immersion in both test solutions due to increase in oxide layer formation on the surface of the Ni-Mo coating. SEM revealed a cracked surface morphology after immersion in sweet high-salinity test solution and elemental analysis shows the presence of oxygen after immersion in both test solutions. The oxygen content increased from 1.70 wt% after immersion in sweet low-salinity test solution to 2.37 wt% after immersion in sweet high-salinity test solution.

Improving the Surface Characteristics by Employing FSP on the Composites for the Automobile Brake Pad Application

2019 ◽  
Author(s):  
P. Ashwath ◽  
M. Anthony Xavior ◽  
R. Rajendran
Keyword(s):  
Surface Characterization ◽  
Research Work ◽  
Hot Extrusion ◽  
Surface Characteristics ◽  
Extrusion Process ◽  
Wear Loss ◽  
Brake Disc ◽  
Brake Pad ◽  
Brake Pads ◽  
Friction Stir

Abstract Looking at the background of the recent research on the area of the brake friction materials, composites are gaining the trust in being a potential replacement among the automobile sectors. The fabrication of the AA 2024 composites reinforced with 3 wt % Al2O3 is done using powder metallurgy technique followed by hot extrusion process. Current research work focuses on friction stir processed surface modified composites evaluated for the replacement of the currently used brake pads materials in automobile sectors. Surface characterization is carried out on the worn-out tracks of both brake materials developed and the counterpart employed using scanning electron microscope and XRD. The counterpart used in pin on disc configuration is exactly the material used in the automobile application (i.e. automobile brake disc plate material). Impact characteristics and tensile studies after friction stir processing (FSP) is studied as well. Coefficient of friction and wear loss characteristics in aspect of the tribological life of the composites developed is compared with the existing automobile brake pad components and found that FSP on composites served the purpose of the materials used in existing brake pads material.

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