Determination of Formation Organic Carbon Content Using a New Neutron-Induced Gamma Ray Spectroscopy Service that Directly Measures Carbon

2013 ◽  
Author(s):  
Jorge Gonzalez ◽  
Richard Lewis ◽  
James Hemingway ◽  
Jim Grau ◽  
Erik Rylander ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Carbon Content ◽  
Gamma Ray ◽  
Organic Carbon Content ◽  
Gamma Ray Spectroscopy

scholarly journals Determination of soil specific surface area by water vapor adsorption: I Drying of soil samples

1987 ◽  
Vol 59 (2) ◽  
pp. 63-65
Author(s):  
Raina Niskanen ◽  
Väinö Mäntylahti
Keyword(s):  
Organic Carbon ◽  
Carbon Content ◽  
Mineral Soil ◽  
Clay Content ◽  
Fine Sand ◽  
Water Vapor Adsorption ◽  
Soil Samples ◽  
Organic Carbon Content ◽  
Clay Sample

Drying of three mineral soil samples (clay content 4—58 %, organic carbon content 1—5 %) equilibrated at 75.5 % relative humidity was studied. The soils were dried in an oven at +50°C, +70°C and + 105°C for 4 and 8 hours and in a desiccator over pure concentrated H2SO4 and P2O5. Drying over desiccants for 8 hours removed less water than drying at + 50°C. Drying over desiccants for 3—7 days was as efficient as drying at +70°C, for 14—24 days as efficient as 4 hours of drying at + 105°C. Eight hours of drying at + 105°C seemed to be too drastic, because it caused a greater weight loss in the clay sample of 5 % organic carbon content than did prolonged desiccant-drying. Drying at + 70°Cremoved as much water from fine sand which contained 4 % clay as prolonged desiccant-drying.

scholarly journals Comparative study of the methods for the determination of organic carbon and organic matter in soils, compost and sludge

2019 ◽  
Vol 51 (3) ◽  
pp. 342-347 ◽  
Author(s):  
V. R. Angelova ◽  
V. I. Akova ◽  
K. I. Ivanov
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Carbon Content ◽  
Organic Content ◽  
Correction Coefficient ◽  
Organic Carbon Content ◽  
Wide Range ◽  
High Organic Content ◽  
Very High

The aim of this study was to compare the most commonly used methods for the determination of organic carbon (OC) and organic matter (SOM), and evaluate the capability of LOI (loss on ignition method) to estimate OC, using reference soils, compost and sludge as standards. The use of a titrimetric endpoint (adding phosphoric acid prior to titration) is more suitable for assessing the level of organic carbon in soils with low, medium, high and very high content. The use of a photometric endpoint is more appropriate for samples of medium and high carbon content. LOI 400 and LOI 450 may also be used for the determination of samples with a high organic content whereas LOI 450 - in the determination of samples with an average organic content. LOI 450 can be used to evaluate SOC in a wide range of organic matter concentrations (3-55%). Indirect assessment of the organic carbon content or organic matter using a correction coefficient is not very accurate for samples with average organic carbon content. Keywords: methods, organic carbon, organic matter, certified samples

Determination of Total Organic Carbon Content in Shale Formations With Regression Analysis

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Jianguo Wang ◽  
Daihong Gu ◽  
Wei Guo ◽  
Haijie Zhang ◽  
Daoyong Yang
Keyword(s):  
Organic Carbon ◽  
Total Organic Carbon ◽  
Gamma Ray ◽  
Relative Difference ◽  
Absolute Difference ◽  
Organic Carbon Content ◽  
Shale Formations ◽  
The Difference ◽  
T Distribution

By correcting both the positive and negative ΔlogR separation resulting from the resistivity in organic-deficient shales, the traditional ΔlogR correlation is modified, validated, and applied to determine the total organic carbon (TOC) content in shale formations. The TOC content is determined once the Fisher distribution, which represents the significance of each model, and Student's t-distribution, which denotes the significance of every variable in the models, have achieved values equal to or higher than their respective threshold values at a confidence level of 95%. Using a total of 45 sets of logging measurements, the newly proposed correlation is found to be able to reproduce the measured TOC values with a root mean-squared absolute difference (RMSAD) of 0.30 wt % and root mean-squared relative difference (RMSRD) of 23.8%, respectively. Uranium concentration, apart from interval transit time and resistivity, is found to be key in determining the TOC content in organic-rich shale without other radioactive minerals. By combining the reading of DGR (i.e., the difference between the spectral gamma ray with the radioactivity and the computed gamma ray without uranium), the traditional ΔlogR technique has now been improved and extended to the negative ΔlogR separation resulting from the resistivity in organic-deficient shale higher than that in organic-rich shale.

scholarly journals Variability of topsoil properties at the southern coast of Finland and the number of  soil samples needed for the estimation of soil properties

1983 ◽  
Vol 55 (2) ◽  
pp. 109-117
Author(s):  
Raili Jokinen
Keyword(s):  
Organic Carbon ◽  
Soil Properties ◽  
Carbon Content ◽  
Field Experiments ◽  
Available P ◽  
Organic Carbon Content ◽  
Plant Available P ◽  
Bray 1 ◽  
Extractable Al

A total of 430 topsoil samples were collected from ten fields of the Viikki Experimental Farm, University of Helsinki. Particle size distribution, organic carbon content, pH(CaCl2), exchangeable Ca, Mg, K contents, plant available P (Bray 1), 1 M KCI extractable (Al+H) content and effective cation exhange capacity of the soils were determined. The coefficient of variation was used as indicator of the variability of soil properties with in each field. The lowest coefficients of variation were observed for pH(CaCl2) and the highest for exchangeable Mg 1 M KCI extractable (Al+H) and effective cation exchange capasity. The results indicate that from 1 (pH(CaCl2)) to 33 (exchangeable Mg) samples per hectare are needed from individual fields for strict level of accuracy in estimation of the soil properties. For determination of soil type (according to clay content) and organic carbon content on average 8 samples, and for the plant available P (Bray 1) and exchangeable Mg and K contents 10 to 16 samples per hectare appear sufficient. Four samples suffice for a less stringent, lax accurate determination of all properties. The variability of soil properties is discussed from the viewpoint of agricultural advisory work and field experiments for agricultural research.

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