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Petroleum Geochemical Survey
Published in Muhammad Abdul Quddus, Petroleum Science and Technology, 2021
Vitrinite is maceral, one of the components of coal. Macerals are organic compounds in coal analogous to the minerals of rock. Vitrinite is a vitreous substance, shiny like glass, having a high calorific value associated with volatile matter. The vitrinite reflectance method is frequently applied for the maturity determination of coal and petroleum kerogen. It is an optical method. Originally the method was developed for coal evaluation and its rank (maturity) determination. Vitrinite compounds are also found in petroleum kerogen, so the method was extended for the determination of kerogen maturity. Vitrinite reflectance is defined as ‘An average of a series of measurements of the percentage of incident white light reflected from the vitrinite macerals at a 500× magnification in the oil immersion’.
o numerical simulation in assessment of energy resources – a case study of Permo-Carboniferous source rocks in the Wuqing Depression, Huabei, China
Published in Wang Yuehan, Ge Shirong, Guo Guangli, Mining Science and Technology, 2004
Yanming Zhu, Yong Qin, Baozhen Yan
Being used as an important indicator of organic maturity level, the vitrinite reflectance has become a wildly used tool in integrated basin analysis, in the exploration or evaluation for oil and gas, and in the coal quality forecast. Many models have been proposed in recovering palaeo-geothermics field and evolution of organic maturation level, which is based on vitrinite reflectance. The simplified model, called EASY%Ro proposed by Sweeney and co-workers, fully incorporates the merits of former models and considers the chemical reaction kinetics to inverse organic heated history and evolution process of maturity. Taking many factors into consideration, being easy in operation and having good result, the EASY%Ro method will certainly play an important role in research on exploration for oil and gas.
Carbonaceous fuels, their properties and testing
Published in Jaroslav Legemza, Mária Fröhlichová, Róbert Findorák, Biomass and Carbon Fuels in Metallurgy, 2019
Jaroslav Legemza, Mária Fröhlichová, Róbert Findorák
Vitrinite is the most frequently and most abundantly represented group of macerals in coal. Vitrinite macerals are identified in coal with higher coalification. Vitrinite almost linearly changes its physical and chemical properties depending on the degree of coalification. It is a chemically reactive component of coal. It releases volatiles and produces sufficient amount of the liquid phase. Vitrinite may be easily distinguished in the microscope.
Prospecting for coking coal in the Plains region of western Canada
Published in CIM Journal, 2022
The rank of the coal is one of the most important parameters in determining the coking potential of any coal deposit. The ASTM method used for rank determination, referred to as ASTM Standard D388 (ASTM International, 2019), uses proximate analysis (Kentucky Geological Survey, 2021) test results to assign the coal rank. A different method, based on microscope observations of the amount of light reflectance of vitrinite, is often claimed to be an alternative approach to the ASTM rank determination. In this method, reflectance measurements of vitrinite are equated to laboratory measurements of volatile matter, fixed carbon, or heat content, as appropriate. However, according to ASTM International (2020), this method may only be “used as an indicator of rank” of the coal, but not for rank determination. ASTM International states that this petrographic approach is only reliable if the coal macerals, specifically the vitrinite, have not been subject to any extraneous influences that affect the reflectance properties of the sample. Unfortunately, the Mannville Group coal has often been subjected to such influences. During the processes of lithification and coalification, Mannville coal may generate and liberate liquid hydrocarbon (i.e., oil). The coal becomes infused with oil and, where this occurs, the light reflectance of the vitrinite may be reduced compared to its normal value. This “reflectance suppression” can lead to incorrectly low estimates of the rank.
How thermal maturity analysis supports stratigraphic restoration in heavily faulted fluvial outcrops: a case study on Strzelecki Group outcrops, West Gippsland, Victoria, Australia
Published in Australian Journal of Earth Sciences, 2020
H. Aghaei, M. Hall, B. Wagstaff
Vitrinite is a common maceral in coal that also occurs as dispersed organic particles within other sedimentary rocks. It undergoes irreversible physical and chemical processes with increasing burial pressures and temperatures known as coalification or maturation. The level of maturation can be determined based on the measurement of the vitrinite reflectance in oil (Ro% or Rv%), which is a well-established means for assessing the thermal history of organic-bearing sediments. Some other methods, such as Thermal Alteration Index (TAI), Conodont Alteration Index (CAI), Tmax (Waples, 1985) and Spore Colour Index (Fisher, Barnard, & Cooper, 1980) can also be used but they are generally less precise.
Vitrinite Maceral Separation Using Column Flotation
Published in International Journal of Coal Preparation and Utilization, 2018
Prasad Kopparthi, Rashmi Singh, D. Nag, A. K. Mukherjee
Measurements of vitrinite reflectance under oil (Ro) were carried out in monochromatic light (546 nm). Reflectance was taken on clean, scratch-free vitrinite (collotelinite) grains. Vitrinite reflection is commonly used to determine the coal rank, which depends on the geological conditions and coalification process. Measurements were carried out on 100 clean vitrinite grains of flotation feed and products and the mean random reflectance was calculated (Ro) for each of them.