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Different Reservoirs (different + reservoir)

Distribution by Scientific Domains

Earth and Environmental Science	100%

Selected Abstracts

Using Rock-Eval 6 pyrolysis for tracking fossil organic carbon in modern environments: implications for the roles of erosion and weathering

EARTH SURFACE PROCESSES AND LANDFORMS, Issue 2 2006
Yoann Copard
Abstract This work relates to the debate on the fossil organic carbon (FOC) input in modern environments and its possible implication for the carbon cycle, and suggests the use of Rock-Eval 6 pyrolysis as a relevant tool for tracking FOC in such environments. Considering that such a delivery is mainly due to supergene processes affecting the continental surface, we studied organic matter in different reservoirs such as bedrocks, alterites, soils and rivers in two experimental catchments at Draix (Alpes de Haute Provence, France). Samples were subjected to geochemical (Rock-Eval 6 pyrolysis) investigations and artificial bacterial degradations. After comparing the geochemical fingerprint of samples, geochemical markers of FOC were defined and tracked in the different reservoirs. Our results confirm the contribution of FOC in modern soils and rivers and display the various influences of weathering and erosional processes on the fate of FOC during its exchange between these pools. In addition, the contrasting behaviour of these markers upon the supergene processes has also highlighted the refractory or labile characters of the fossil organic matter (FOM). Bedrock to river fluxes, controlled by gully erosion, are characterized by a qualitative and quantitative preservation of FOM. Bedrock to alterite fluxes, governed by chemical weathering, are characterized by FOC mineralization without qualitative changes in deeper alterites. Alterite to soils fluxes, controlled by (bio)chemical weathering, are characterized by strong FOC mineralization and qualitative changes of FOM. Thus weathering and erosional processes induce different FOM evolution and affect the fate of FOC towards the global carbon cycle. In this study, gully erosion would involve maintenance of an ancient sink for the global carbon cycle, while (bio)chemical processes provide a source of CO2. Finally, this study suggests that Rock-Eval 6 pyrolysis can be considered as a relevant tool for tracking FOC in modern environments. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Stable water isotope simulation in different reservoirs of Manaus, Brazil, by Community Land Model incorporating stable isotopic effect

INTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 5 2009
Xin-Ping Zhang
Abstract The daily and monthly variations of stable water isotopes in different reservoirs at Manaus, Brazil, are simulated and inter-compared in an equilibrium year, using the Community Land Model (CLM) involving the stable isotopic effects as a diagnostic tool for an in-depth understanding of the hydrometeorological processes. On the daily scale, the ,18O in precipitation, vapour and surface runoff have clear seasonality, with marked negative correlations with the corresponding water amount. However, the ,18O in surface dew displays marked positive correlation with dew amount. On the diurnal time scale, the ,18O in precipitation displays an unclear diurnal variation and an unmarked correlation with the precipitation amount. However, the ,18O in vapour keeps consistency with specific humidity. On the monthly time scale, the ,18O in precipitation and surface runoff displays distinct bimodal seasonality, with two maxima in January and in July, and two minima in April and in October; Vapor displays a similar bimodal pattern, two maxima appear in January and August, and two minima in April and November. The amount effect simulated on the monthly time scale has consistency with the actual survey result at the Manaus station, from 1965 to 1990, set up by International Atomic Energy Agency (IAEA)/World Meteorological Organization (WMO). In addition, the slope (7.49) and the intercept (6.25) of the simulated meteoric water line (MWL) are all smaller than those of the actual mean MWL. However, compared with the annual MWL, the simulated MWL lies within the variation range of actual MWLs. Copyright © 2008 Royal Meteorological Society [source]

Characteristics of Oil Sources from the Chepaizi Swell, Junggar Basin, China

ACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 5 2010
LIU Luofu
Abstract: So far there has been no common opinion on oil source of the Chepaizi swell in the Junggar Basin. Therefore, it is difficult to determine the pathway system and trend of hydrocarbon migration, and this resulted in difficulties in study of oil-gas accumulation patterns. In this paper, study of nitrogen compounds distribution in oils from Chepaizi was carried out in order to classify source rocks of oils stored in different reservoirs in the study area. Then, migration characteristics of oils from the same source were investigated by using nitrogen compounds parameters. The results of nitrogen compounds in a group of oil/oil sand samples from the same source indicate that the oils trapped in the Chepaizi swell experienced an obvious vertical migration. With increasing migration distance, amounts and indices of carbazoles have a regular changing pattern (in a fine linear relationship). By using nitrogen compounds techniques, the analyzed oil/oil sand samples of Chepaizi can be classified into two groups. One is the samples stored in reservoir beds of the Cretaceous and Tertiary, and these oils came from mainly Jurassic source rock with a small amount of Cretaceous rock; the other is those stored in the Jurassic, Permian and Carboniferous beds, and they originated from the Permian source. In addition, a sample of oil from an upper Jurassic reservoir (Well Ka 6), which was generated from Jurassic coal source rock, has a totally different nitrogen compound distribution from those of the above-mentioned two groups of samples, which were generated from mudstone sources. Because of influence from fractionation of oil migration, amounts and ratios of nitrogen compounds with different structures and polarities change regularly with increasing migrating distance, and as a result the samples with the same source follow a good linear relationship in content and ratio, while the oil samples of different sources have obviously different nitrogen compound distribution owing to different organic matter types of their source rocks. These conclusions of oil source study are identical with those obtained by other geochemical bio-markers. Therefore, nitrogen compounds are of great significance in oil type classification and oil/source correlation. [source]