scholarly journals Interpretation of Nitrogen Isotope Profiles in Petroleum Systems: A Review

2021 ◽  
Vol 9 ◽  
Author(s):  
Tracy M. Quan ◽  
Oyeleye O. Adeboye
Keyword(s):  
Nitrogen Isotopes ◽  
Isotopic Fractionation ◽  
Petroleum Reservoirs ◽  
Nitrogen Isotope ◽  
Marine Systems ◽  
Petroleum Systems ◽  
Depositional Processes ◽  
Lab Experiments ◽  
Potential Applications ◽  
General Preference

Bulk sedimentary nitrogen isotope profiles are often used as proxies for depositional redox conditions, nitrogen cycling, and nutrient uptake in modern and ancient marine systems. The general preference in terms of analysis is that the sediments measured have undergone minimal thermal alteration, as post-depositional processes might have altered the initial δ15N signal, thus complicating the interpretation of these records. Although not a traditional proxy for petroleum evaluation purposes, recently the use of nitrogen isotopes in petroleum systems has been investigated as potential proxies to reconstruct paleoenvironmental conditions such as redox, and for organic matter evaluation. In this paper we review the use of nitrogen isotope data in petroleum systems, their interpretations, and factors that may complicate their use as proxies. We review the evidence for nitrogen isotopic fractionation during diagenesis, catagenesis, and fluid migration as determined by lab experiments, and how these might impact interpretation of δ15N data in petroleum systems. We also analyze the use and interpretation of δ15N data from petroleum-producing reservoir units, including unconventional reservoirs and lacustrine basins. Lastly, we discuss potential applications for nitrogen isotopes in petroleum systems with regards to their use as both geochemical proxies and as tools to evaluate petroleum reservoirs.

NITROGEN ISOTOPE FRACTIONATION ASSOCIATED WITH THE NO2− → N2O STEP OF DENITRIFICATION IN SOILS

1982 ◽  
Vol 62 (2) ◽  
pp. 227-241 ◽  
Author(s):  
A. MARIOTTI ◽  
A. LECLERC ◽  
J. C. GERMON
Keyword(s):  
Reaction Rate ◽  
Nitrogen Isotopes ◽  
Reduction Rate ◽  
Isotopic Fractionation ◽  
Nitrogen Isotope ◽  
Isotopic Enrichment ◽  
Experimental Conditions ◽  
Helium Atmosphere ◽  
Higher Temperature ◽  
Incubation Temperatures

The fractionation of the nitrogen isotopes 14N and 15N in the denitrification process has been studied in laboratory experiments for the step NO2− → N2O. This study has been carried out on natural soils under anaerobic conditions (helium atmosphere). Reduction of N2O is blocked by introduction of a small amount of acetylene in the incubator atmosphere. Variation of experimental conditions of incubation (temperatures, direct or after air-drying incubation of the soil, addition of glucose), greatly modify the reaction rate. 15N is enriched in the substrate during denitrification. The isotopic enrichment factor changes with experimental conditions from about −33 to −11‰. Greatest enrichment is obtained for the lowest reduction rate (low temperature, undried soil). For high rates of denitrification (higher temperature, addition of glucose), the isotopic fractionation decreases. An exponential relation is found between isotopic enrichment, εp/s, and the reaction rate.

Observations on the Lower Triassic petroleum prospectivity of the offshore Carnarvon and Roebuck basins

2016 ◽  
Vol 56 (1) ◽  
pp. 173 ◽  
Author(s):  
Stephen Molyneux ◽  
Jeff Goodall ◽  
Roisin McGee ◽  
George Mills ◽  
Birgitta Hartung-Kagi
Keyword(s):  
Regional Analysis ◽  
Lower Triassic ◽  
Source Rocks ◽  
Upper Permian ◽  
Regional Study ◽  
North West ◽  
Petroleum Systems ◽  
The North ◽  
Depositional Processes ◽  
Water Margin

Why are the only commercial hydrocarbon discoveries in Lower Triassic and Permian sediments of the western margin of Australia restricted to the Perth Basin and the Petrel Sub-basin? Recent regional analysis by Carnarvon Petroleum has sought to address some key questions about the Lower Triassic Locker Shale and Upper Permian Chinty and Kennedy formations petroleum systems along the shallow water margin of the Carnarvon and offshore Canning (Roebuck/Bedout) basins. This paper aims to address the following questions:Source: Is there evidence in the wells drilled to date of a working petroleum system tied to the Locker Shale or other pre-Jurassic source rocks? Reservoir: What is the palaeogeography and sedimentology of the stratigraphic units and what are the implications for the petroleum systems?The authors believed that a fresh look at the Lower Triassic to Upper Permian petroleum prospectivity of the North West Shelf would be beneficial, and key observations arising from the regional study undertaken are highlighted:Few wells along a 2,000 km area have drilled into Lower Triassic Locker Shale or older stratigraphy. Several of these wells have been geochemically and isotopically typed to potentially non Jurassic source rocks. The basal Triassic Hovea Member of the Kockatea Shale in the Perth Basin is a proven commercial oil source rock and a Hovea Member Equivalent has been identified through palynology and a distinctive sapropelic/algal kerogen facies in nearly 16 wells that penetrate the full Lower Triassic interval on the North West Shelf. Samples from the Upper Permian, the Hovea Member Equivalent and the Locker Shale have been analysed isotopically indicating –28, –34 and –30 delta C13 averages, respectively. Lower Triassic and Upper Permian reservoirs are often high net to gross sands with up to 1,000 mD permeability and around 20% porosity. Depositional processes are varied, from Locker Shale submarine canyon systems to a mixed carbonate clastic marine coastline/shelf of the Upper Permian Chinty and Kennedy formations.

scholarly journals Approaches to Estimating Marine Protein in Human Collagen for Radiocarbon Date Calibration

Radiocarbon ◽  
2010 ◽  
Vol 52 (4) ◽  
pp. 1611-1625 ◽  
Author(s):  
Genevieve Dewar ◽  
Susan Pfeiffer
Keyword(s):  
South Africa ◽  
Case Studies ◽  
Carbon Isotope ◽  
Nitrogen Isotope ◽  
Western Cape ◽  
Radiocarbon Dates ◽  
Mean Values ◽  
Marine Systems ◽  
Human Collagen ◽  
Marine Protein

Determining the appropriate approach to calibrating radiocarbon dates is challenging when unknown and variable fractions of the carbon sample are derived from terrestrial and marine systems. Uncalibrated dates from a large number of human skeletons from Western Cape and Southern Cape locales, South Africa (n = 187), can be used to explore alternate approaches to the marine carbon correction. The approach that estimates theoretically expected minimum and maximum values for marine carbon (“expected”) is compared to the approach that estimates observed minimum and maximum values (“observed”). Two case studies are explored, wherein skeletons interred together have non-overlapping conventional 14C ages. The case from the Western Cape is explored through carbon isotope values; the case from the Southern Cape uses nitrogen isotope values. In both cases, the approach using observed endpoints yields better date calibration results. Analysis of the large sample shows that mean values for estimated dietary % Marine, as calculated using expected and observed protocols, are significantly different. We conclude that the observed protocol is preferred, and that improved measures of the local marine reservoir (ΔR) are needed for this region.

Nitrogen Isotope Exchange between Liquid N2O3 and NO at Low Temperature and Elevated Pressure

1963 ◽  
Vol 18 (2) ◽  
pp. 235-241 ◽  
Author(s):  
E. U. Monse ◽  
Lois Nash Kauder ◽  
W. Spindel
Keyword(s):  
Low Temperature ◽  
Separation Factor ◽  
Isotope Exchange ◽  
Spectroscopic Data ◽  
Room Temperature ◽  
Nitrogen Isotopes ◽  
Nitrogen Isotope ◽  
Elevated Pressure ◽  
Single Stage ◽  
Stage Separation

The single stage separation factor, a, for nitrogen isotope exchange between liquid N2O3—N2O4-mixtures and their vapor has been measured at temperatures ranging from — 76°C to room temperature and pressures between 1 atm. and 7.4 atm.At —76°C and 1 atm., α = 1.061 ± 0.003;at —23°C and 1 atm., α=1.034 ± 0.002;at +23°C and 2.1 atm., α=1.017 ± 0.002;at +23°C and 7.4 atm., α=1.030 ± 0.002.The results are compared with values, calculated from spectroscopic data for N2O3, N2O4, NO and NO2. The value of α = 1.030 found at room temperature and 7.4 atm. pressure enhances the usefulness of the N2O3—NO-system for separating the nitrogen isotopes, since it eliminates the need of refrigeration.

APPLICATIONS FOR BOREHOLE GEOPHYSICS IN GEOPHYSICAL EXPLORATION

Geophysics ◽  
1970 ◽  
Vol 35 (1) ◽  
pp. 81-92 ◽  
Author(s):  
G. R. Pickett
Keyword(s):  
Oil And Gas ◽  
Measurement Techniques ◽  
Petroleum Reservoirs ◽  
Stratigraphic Correlation ◽  
Borehole Geophysics ◽  
Shear Wave Velocities ◽  
Quantitative Measurements ◽  
Lithology Identification ◽  
Surface Exploration ◽  
Potential Applications

Most geophysicists are familiar with the use of well logs for stratigraphic correlation and perhaps for estimating volumes of oil and gas in place. Over the years, additions to the array of available borehole measurement techniques have led to additional capabilities perhaps not as well known. There are several dozen borehole measurements currently available. Problems involved in extracting useful data under practical conditions with acceptable costs from these measurements pose constraints on complete utilization. Nevertheless, potential applications for such measurements include estimation of recoverable hydrocarbons from petroleum reservoirs, identification of geological environments, derivation of compressional and shear‐wave velocities and attenuations, quantitative measurements of lithology, identification of “flushed” hydrocarbon reservoirs and fluid migration paths, and identification of potential reservoirs. These and other borehole measurement capabilities have important ramifications toward making surface exploration methods more effective. It is concluded that a better marriage of borehole geophysics to surface exploration techniques should be rewarding both to the borehole specialist and to the surface explorationist.

Isotopic Evidence for Diet in the Seventeenth-Century Colonial Chesapeake

2003 ◽  
Vol 68 (1) ◽  
pp. 129-139 ◽  
Author(s):  
Douglas H. Ubelaker ◽  
Douglas W. Owsley
Keyword(s):  
Seventeenth Century ◽  
Carbon Isotope ◽  
Nitrogen Isotopes ◽  
Dietary Diversity ◽  
Stable Carbon Isotope ◽  
Isotope Analysis ◽  
Nitrogen Isotope ◽  
Stable Carbon ◽  
Carbon And Nitrogen ◽  
American Colonies

Excavations of colonial period sites in Maryland and Virginia have produced human remains dating to the seventeenth century. In this study, we analyze stable isotopes of carbon and nitrogen from these remains to explore aspects of the diets of the individuals represented. Analyses of both stable carbon and nitrogen isotopes were conducted on preserved protein while stable carbon isotope analysis was also conducted on preserved biological apatite. Carbon isotope values (δ13N‰) ranged from -10.5 to -20.5 for collagen and -5.1 to -12.5 for bioapatite. Nitrogen isotope values (δ15N‰) ranged from 9.9 to 14.4. The data suggest dietary diversity among the individuals examined. Three factors contribute to this diversity: the availability of maize, variation in immigration histories of the individuals, and the differing lengths of time they spent in the American colonies.

scholarly journals Negligible isotopic fractionation of nitrogen within temperate <i>Zostera</i> spp. meadows

2018 ◽  
Author(s):  
Douglas G. Russell ◽  
Wei Wen Wong ◽  
Perran L. M. Cook
Keyword(s):  
Nitrogen Fixation ◽  
Coastal Zone ◽  
Solid Phase ◽  
Isotopic Fractionation ◽  
Nitrogen Isotope ◽  
Small Contribution ◽  
Seagrass Beds ◽  
Seagrass Meadows ◽  
Nitrogen Inputs ◽  
External Sources

Abstract. Seagrass meadows form an ecologically important ecosystem in the coastal zone. Excessive nitrogen inputs to the coastal zone pose a key threat to seagrass through eutrophication and associated algal overgrowth. The 15N / 14N ratio of seagrass is commonly used to assess extent to which sewage derived nitrogen may be influencing seagrass beds. There have however, been no studies comparing the 15N / 14N ratios of seagrass beds, their associated sediments and of critical importance, the porewater NH4+ pool, which is most bioavailable. Here, we undertook a study of the 15N / 14N ratios of seagrass tissue, sediment porewater NH4+ pool and the sediment solid phase to elucidate the extent of any fractionating processes taking place during organic matter mineralisation and nitrogen assimilation. The study was undertaken within two coastal embayments known to receive nitrogen from a range of sources including marine, urban and sewage sources. The δ15N of porewater ammonium was strongly correlated with the δ15N of both the sediment solid phase and seagrass tissue (r2 of 0.89 and 0.85) respectively. The δ15N porewater NH4+ minus the δ15N seagrass tissue ranged between −1.4 and 7 ‰ with an average 1.6 ‰. We suggest the most likely explanation for this was fractionation during assimilation as a consequence of diffusion limitation, although the magnitude of this change was relatively small. Nitrogen fixation may have also contributed a small amount to the observed isotopic depletion of the plants relative to the sediment porewater NH4+ pool. A consideration of the nitrogen isotope values of the seagrass bed nitrogen pools compared to external sources suggest the dominant source of nitrogen to seagrass is recycling from within the bed, with a relatively small contribution from water column assimilation, particulate trapping and nitrogen fixation.

Intra-Community Variation in Diet during the Adoption of a New Staple Crop in the Eastern Woodlands

2008 ◽  
Vol 73 (3) ◽  
pp. 413-439 ◽  
Author(s):  
Fionnuala Rose
Keyword(s):  
Nitrogen Isotopes ◽  
Nitrogen Isotope ◽  
Bimodal Distribution ◽  
Bone Collagen ◽  
Middle Woodland ◽  
Eastern Woodlands ◽  
Intensive Exploitation ◽  
Central Illinois ◽  
Staple Crop ◽  
River Valleys

This study investigated intracommunity variation in diet during the introduction and adoption of a new staple crop (maize) into an indigenous horticultural system. Carbon and nitrogen isotopes of human bone collagen were analyzed from five sites in west-central Illinois, dating from the Middle Woodland to Mississippian periods, and the results contrasted with evidence from neighboring river valleys and the wider Eastern Woodlands area. Contrary to speculation, neither the initial adoption of maize nor subsequent intensification in its use were correlated with status, gender, or age. A striking bimodal distribution was observed in consumption of native and introduced crops; growing or eating small amounts of maize was apparently not practiced. Fluoride dating confirms the burials are contemporary, and the pattern persists over several hundred years. Possible explanations include issues related to the economics of maize growing, household requirements for storage, exchange, or levies, or individual taste. Also notable were earlier-than-expected dates for intensive exploitation of the maize in this area, in the early Late Woodland, possibly as early as A.D. 400. Nitrogen isotope ratios were higher for males at all sites and time periods; the cause may have been greater access to dietary protein, or could be the result of physiological differences.

Stable Isotope Evidence for Maize Horticulture and Paleodiet in Southern Ontario, Canada

1995 ◽  
Vol 60 (2) ◽  
pp. 335-350 ◽  
Author(s):  
M. Anne Katzenberg ◽  
Henry P. Schwarcz ◽  
Martin Knyf ◽  
F. Jerome Melbye
Keyword(s):  
Stable Isotope ◽  
North America ◽  
Material Culture ◽  
Nitrogen Isotopes ◽  
Nitrogen Isotope ◽  
Extraction Methods ◽  
Animal Protein ◽  
Bone Collagen ◽  
Southern Ontario ◽  
Isotope Data

This paper reports new data on stable carbon and nitrogen isotopes obtained from human skeletal remains found at six prehistoric sites dating between A.D. 400 and 1500 in southern Ontario. Analyses examine more closely the timing and intensity of maize adoption and the importance of animal protein in the diet, adding to earlier work in the region by the same authors (Schwarcz et al. 1985). As a result of changes in preferred methods of extracting bone collagen, a comparison of extraction methods is presented. Results indicate a gradual increase in the importance of maize in the diet over a period of approximately 600 years, from A.D. 650 to 1250, and little change in nitrogen isotope values during the same period. The results are considered within the larger temporal and geographical framework of eastern North America, drawing on stable isotope results from the published literature. Both paleobotanical and isotope data indicate marked differences in the timing and intensity of maize utilization in different regions of northeastern North America. Nitrogen isotope values decrease after around A.D. 1350, suggesting a decrease in animal protein in the diet. Stable isotope data provide one source of evidence for changes in human subsistence patterns and their interpretation relies on complementary data from sources such as the analysis of faunal and botanical remains, settlement patterns, and material culture.

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