Variation in immune function, body condition, and feather corticosterone in nestling Tree Swallows (Tachycineta bicolor) on reclaimed wetlands in the Athabasca oil sands, Alberta, Canada

In the Athabasca oil sands region of northern Alberta, mining companies are evaluating reclamation using constructed wetlands for integration of tailings. From May to July 2008, reproductive performance of 40 breeding pairs of tree swallows (Tachycineta bicolor), plus growth and survival of nestlings, was measured on three reclaimed wetlands on two oil sands leases. A subset of nestlings was examined for i) feather corticosterone levels, ii) delayed-type hypersensitivity response, and iii) innate immune function. Nestlings on one of two wetlands created with oil sands process affected material (OSPM) were heavier and had greater wing-lengths, and mounted a stronger delayed-type hypersensitivity response compared those on the reference wetland. Corticosterone was significantly higher in male nestlings on one of two OSPM-containing wetland compared to the reference wetland. Body condition of 12-day-old female nestlings was inversely related to feather corticosterone. Under ideal weather conditions, reclaimed wetlands can support healthy populations of aerially-insectivorous birds.     

Effects of temperature and fertilization on total vs. active bacterial communities exposed to crude and diesel oil pollution in NW Mediterranean Sea

The dynamics of total and active microbial communities were studied in seawater microcosms amended with crude or diesel oil at different temperatures (25, 10 and 4 °C) in the presence/absence of organic fertilization (Inipol EAP 22). Total and hydrocarbon-degrading microbes were enumerated by fluorescence microscopy and Most Probable Number (MPN) method, respectively. Total (16S rDNA-based) vs. active (16S rRNA) bacterial community structure was monitored by Capillary-Electrophoresis Single Strand Conformation Polymorphism (CE-SSCP) fingerprinting. Hydrocarbons were analyzed after 12 weeks of incubation by gas chromatography-mass spectrometry. Total and hydrocarbon-degrading microbial counts were highly influenced by fertilization while no important differences were observed between temperatures. Higher biodegradation levels were observed in fertilized microcosms. Temperature and fertilization induced changes in structure of total bacterial communities. However, fertilization showed a more important effect on active bacterial structure. The calculation of Simpson's diversity index showed similar trends among temperatures whereas fertilization reduced diversity index of both total and active bacterial communities.     

Can oil prices help estimate commodity futures prices? The cases of copper and silver

There is an extensive literature on modeling the stochastic process of commodity futures. It has been shown that models with several risk factors are able to adequately fit both the level and the volatility structure of observed transactions with reasonable low errors.     

Terrestrial exposure of oilfield flowline additives diminish soil structural stability and remediative microbial function

Onshore oil production pipelines are major installations in the petroleum industry, stretching many thousands of kilometres worldwide which also contain flowline additives. The current study focuses on the effect of the flowline additives on soil physico-chemical and biological properties and quantified the impact using resilience and resistance indices. Our findings are the first to highlight deleterious effect of flowline additives by altering some fundamental soil properties, including a complete loss of structural integrity of the impacted soil and a reduced capacity to degrade hydrocarbons mainly due to: (i) phosphonate salts (in scale inhibitor) prevented accumulation of scale in pipelines but also disrupted soil physical structure; (ii) glutaraldehyde (in biocides) which repressed microbial activity in the pipeline and reduced hydrocarbon degradation in soil upon environmental exposure; (iii) the combinatory effects of these two chemicals synergistically caused severe soil structural collapse and disruption of microbial degradation of petroleum hydrocarbons.     

含油污泥调剖技术在陇东油田悦29区的应用

针对长庆陇东油田悦29区注水平面矛盾突出的特点,优选了含油污泥调剖技术。详细介绍了调剖体系的配制,调剖体系性能测试表明其相关性能指标满足要求。进行了驱替模拟试验,结果表明:其封堵作用可以维持较长时间,通过对不同注水井组进行现场应用,显示该技术能改善水驱开发效果,可以满足油藏深部封堵大孔道的技术要求,有增油降水效果。     

A detailed field-based evaluation of naphthenic acid mobility in groundwater

An anaerobic plume of process-affected groundwater was characterized in a shallow sand aquifer adjacent to an oil sands tailings impoundment. Based on biological oxygen demand measurements, the reductive capacity of the plume is considered minimal. Major dissolved components associated with the plume include HCO₃, Na, Cl, SO₄, and naphthenic acids (NAs). Quantitative and qualitative NA analyses were performed on groundwater samples to investigate NA fate and transport in the subsurface. Despite subsurface residence times exceeding 20 years, significant attenuation of NAs by biodegradation was not observed based on screening techniques developed at the time of the investigation. Relative to conservative tracers (i.e., Cl), overall NA attenuation in the subsurface is limited, which is consistent with batch sorption and microcosm studies performed by other authors. Insignificant biological oxygen demand and low concentrations of dissolved As (< 10 µg L^− 1) in the plume suggest that the potential for secondary trace metal release, specifically As, via reductive dissolution reactions driven by ingress of process-affected water is minimal. It is also possible that readily leachable As is not present in significant quantities within the sediments of the study area. Thus, for similar plumes of process-affected groundwater in shallow sand aquifers which may occur as oil sands mining expands, a reasonable expectation is for NA persistence, but minimal trace metal mobilization.     

Age-dating Diesel Fuel Spills: Using the European Empirical Time-based Model in the U.S.A.

In 1993, a paper was published by Christensen and Larsen that offered a method for determining the age of diesel oil spills in soil (Christensen and Larsen, 1993 Ground Water Mount. R . Fall , 142-149). It presented an empirical time-based model of the degradation of diesel fuel in soils using chemical data gathered at petroleum release sites in Denmark and the Netherlands. Now, evaluation of the validity of the application of this work to subsurface petroleum releases in other countries remains. In the U.S.A., investigations assessing date(s) of release of diesel fuel in soils, e.g. age dating of subsurface petroleum contamination, have considerable interest. Litigation-driven scientific investigations with accompanying expert testimony in a court of law are underway. The number of instances where application of the Christensen and Larsen empirical time-based model to petroleum-contaminated properties is growing in the U.S.A. This paper presents two case studies which evaluate the applicability of the Christensen and Larsen empirical time-based model to petroleum-contaminated properties in general. It illustrates the approach using gas chromatographic data from two recently-completed projects evaluating the applicability of the Christensen and Larsen model to a No. 2 fuel oil/diesel fuel surface spill in the U.S.A. Results showed that the application of the model to petroleum-contaminated soils was scientifically valid, provided its applicability was evaluated using hypothesis testing for specific changes in the characteristics of the petroleum hydrocarbon distribution in a number of soil samples collected over time at one site. The paper offers observations on the application of the Christensen and Larsen model to petroleum found in the light non-aqueous phase liquid (LNAPL) phase and groundwater.     

Round Robin Study--Oil Spill Identification

As part of the ongoing work to develop new guidelines for oil spill identification for the European Committee for Standardization (CEN), a Round Robin test was arranged by SINTEF in co-operation with the Norwegian General Standardizing Body (NAS). Twelve laboratories from ten countries participated in the Round Robin study. They include: Denmark, Finland, France, Germany, the Netherlands, Norway, Scotland, Sweden, Wales, and the U.S.A. The analytical methodology used for the Round Robin testing is a result of the ongoing project "Revision of the Nordtest Methodology for Oil Spill Identification". The analytical methodology is described in the AMOP proceedings 2002. Seven oil samples (two artificially weathered "spill" samples and five possible sources) were analyzed following the recommended analytical protocols. The Round Robin study was a "difficult case", because the two spill samples and three of the suspected sources were highly correlated to one another. These samples were from the same oil field in the North Sea, but from different production wells. The present paper summarizes the Round Robin study, and demonstrates the potential of this methodology as a strong technically defensible tool in oil spill identification due to its ability to distinguish qualitatively similar oils from a spill and any available candidate source.     

Compositional Changes of Aromatic Steroid Hydrocarbons in Naturally Weathered Oil Residues in the Egyptian Western Desert

Naturally weathered oil residues from an arid dumpsite in Al-Alamein, Egypt were analyzed for monoaromatic and triaromatic steranes to demonstrate the utility of biomarker compounds in assessing the chemical composition changes during the degradation of the released oil residues in a terrestrial environment. The characterizations of individual aromatic compounds were based on gas chromatography/mass spectrometry (GC/MS) analyses. The results showed that triaromatic sterane distributions were similar in the oil residues of varying weathering degradation extents and correlated with a fresh crude oil sample of the Western Desert-sourced oil. Molecular ratios of triaromatic sterane compounds (ratios of C 28 20R /C 28 20S , C 27 20R /C 28 20R , and C 28 20S /[C 26 20R + C 27 20S ]) were proved to be suitable for source identification. Major changes in chemical compositions during weathering of the oil residues were the depletion of short chain mono- and tri-aromatic steranes in samples that had undergone extensive degradation. The results of triaromatic sterane distribution are in good agreement with weathering classification based on the analyses of saturate and aromatic hydrocarbons and the ratios of n -alkanes, PAHs and saturate biomarker compounds.