154 results on '"Paul Philp"'
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2. La Luna Formation, Venezuela. A Prospective Unconventional Reservoir
- Author
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Andreina Liborius-Parada, R. Paul Philp, and Roger Slatt
- Subjects
Geophysics ,Geology - Abstract
Since the early 2000s, the exploitation of unconventional reservoirs has become very important to the oil and gas industry because of their high potential source of energy and economic value. Venezuela possesses a world-class hydrocarbon source rock in one of the most prolific hydrocarbon basins in the world, namely the Cretaceous La Luna Formation in the Maracaibo Basin. Outcrop and core samples collected from the northwestern Maracaibo Basin provided the database for this study. A comprehensive multiscale characterization of the samples was undertaken to unravel the stratigraphic properties of the petroleum system. In addition, a geochemical approach was taken to evaluate the prospectivity of the La Luna Formation as an unconventional resource in the Maracaibo Basin. Rock-Eval pyrolysis and biomarker data indicate that the La Luna Formation is dominated by type II kerogen, indicating an oil-prone marine organic matter origin. Total organic carbon values ranged between 3.85 wt% and 9.10 wt%. Distributions of isoprenoids, steranes, and terpanes including gammacerane and monoaromatic steroid hydrocarbons indicated a hypersaline, marine carbonate anoxic depositional environment. Thermal maturity parameters indicate that most of the cores are currently in the oil window. This combined stratigraphic geochemical study indicates that the La Luna Formation has excellent potential as an unconventional reservoir for oil and gas in the study area. more...
- Published
- 2023
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Catalog
3. List of Contributors
- Author
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Adhikari, Puspa L., primary, Adkins, Matthew, additional, Albaigés, Joan, additional, Bacosa, Hernando P., additional, Baker, Gregory, additional, Baldassare, Fred, additional, Bayona, Josep M., additional, Beegle-Krause, C.J., additional, Benotti, Mark J., additional, Birkholz, Detlef A., additional, Blaga, Cornelia, additional, Bong, Chui-Wei, additional, Bosman, Samantha H., additional, Brown, Carl E., additional, Brunswick, Pamela, additional, Chanton, Jeffrey P., additional, Chapman, Elizabeth, additional, Chen, Mei-Hua, additional, Chever, Fanny, additional, Christensen, Jan H., additional, Corley, Julie, additional, Crowley, Deborah, additional, de la Torre, Laura, additional, de Oliveira, Olívia M.C., additional, de Souza Queiroz, Antônio F., additional, Dela Cruz, Majbrit, additional, Domínguez, Carmen, additional, Douglas, Gregory S., additional, Driskell, William B., additional, Emsbo-Mattingly, Stephen, additional, Esquinas, Noemi, additional, Evans, Meredith M., additional, Fitz, Nicolas, additional, Franks, James S., additional, French-McCay, Deborah P., additional, Gallego, José Luis R., additional, Gallotta, Fabiana D.C., additional, Gravel, A.J., additional, Guyomarch, Julien, additional, Hardenstine, Jeffery, additional, Harrill, Joshua A., additional, He, Shijie, additional, Healey, Edward (Ted), additional, Ho, Ching-Jen, additional, Hollebone, Bruce, additional, Horn, Matthew, additional, Hung, Wei-Nung, additional, Jayko, Katherine, additional, Jezequel, Ronan, additional, Kienhuis, Paul G.M., additional, Kim, Marcus, additional, Kind, John A., additional, Krahforst, Kerylynn, additional, Kristensen, Mette, additional, Kruge, Michael A., additional, Kuhlman, Christopher L., additional, Lambert, Patrick, additional, Landriault, Mike, additional, Lara-Gonzalo, Azucena, additional, Larter, Stephen R., additional, Layland, Sandra, additional, Lefkovitz, Lisa, additional, Li, Yuanwei, additional, Li, Zhengkai, additional, Lima, Danúsia F., additional, Litman, Eric, additional, Liu, Bo, additional, Liu, Xiaoxing, additional, Liu, Zhanfei, additional, Mendelsohn, Daniel, additional, Meniconi, Maria de F.G., additional, Meyer, Buffy M., additional, Miles, Martin Scott, additional, Millner, Glenn C., additional, Mills, Marc A., additional, Moreira, Ícaro T.A., additional, Nony, Paul A., additional, Oldenburg, Thomas B.P., additional, Olson, Gregory M., additional, Overton, Edward B., additional, Papineau, Joseph, additional, Park, Grace, additional, Payne, James R., additional, Peschier, Leo, additional, Paul Philp, R., additional, Poulsen, Kristoffer G., additional, Radović, Jagoš R., additional, Reyes, Claudia Y., additional, Rogers, Kelsey L., additional, Runciman, David, additional, Shang, Dayue, additional, Silva, Carine S., additional, Spaulding, Malcolm L., additional, Stout, Scott A., additional, Todd, Gordon, additional, Tolosa, Imma, additional, Tomasi, Giorgio, additional, Vaezzadeh, Vahab, additional, van Aggelen, Graham, additional, Wagener, Angela de L.R., additional, Wang, Chuanyuan, additional, Wang, Qing, additional, Wang, Zhendi, additional, Wnek, Shawn M., additional, Wong, Wendy, additional, Wu, Suh-Huey, additional, Yang, Chun, additional, Yang, Zeyu, additional, Zakaria, Mohamad P., additional, Zhang, Gong, additional, and Zhang, Haijiang, additional more...
- Published
- 2018
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4. Productivity and paleoclimatic controls on source rock character in the Aman Trough, north central Sumatra, Indonesia
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Rodriguez, Norelis D. and Paul Philp, R.
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- 2012
- Full Text
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5. Geochemical characterization of the Upper Mississippian Goddard Formation, Noble Ranch Group, and related oils in the Anadarko Basin of Oklahoma
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R. Paul Philp and Catherine A. Pearson
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020209 energy ,Geochemistry ,Energy Engineering and Power Technology ,Geology ,02 engineering and technology ,Structural basin ,Hopanoids ,Fuel Technology ,Biomarker (petroleum) ,Source rock ,Geochemistry and Petrology ,Group (stratigraphy) ,0202 electrical engineering, electronic engineering, information engineering ,Earth and Planetary Sciences (miscellaneous) ,Potential source ,Oil shale - Abstract
The Woodford Shale is anecdotally assumed to be the major source of oil for plays in the Anadarko Basin, including the stacked oil and condensate play in the southcentral Oklahoma oil province (SCOOP). However, there is little published geochemical work to confirm this assumption. This study set out to identify a characteristic geochemical fingerprint for the Goddard Formation, another potential source rock in the SCOOP, to determine if the Goddard is contributing to oil accumulations within the SCOOP. The Upper Mississippian Goddard Formation has been a target for unconventional production in SCOOP since 2012. Published geochemical interpretations for the Goddard Formation are still limited, and this study represents the first detailed oil–source rock correlation for the Goddard in the SCOOP area. The most characteristic geochemical signature of the Goddard extracts is a predominance of tricyclic terpanes relative to the hopanes in the mass-to-charge ratio 191 chromatogram, possibly related to enrichment via thermal stress or a unique source signature. Additional distinctive signatures were also identified for the triaromatic steroid hydrocarbons, sesquiterpenoids, and steranes. The biomarker fingerprints of SCOOP oils are nearly identical with those of the Goddard extracts in this study. Oils in the SCOOP, therefore, appear to originate from a Mississippian source, such as the Goddard rather than the Woodford. This observation demonstrates the value of oil–source rock correlation studies and suggests that there may be effective source rocks in the Anadarko Basin that have been overlooked in the past and should be re-evaluated in detail. more...
- Published
- 2019
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6. Oil families and inferred source rocks of the Woodford–Mississippian tight oil play in northcentral Oklahoma
- Author
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R. Paul Philp and Ting Wang
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Maturity (geology) ,Total organic carbon ,020209 energy ,Tight oil ,Geochemistry ,Energy Engineering and Power Technology ,Geology ,02 engineering and technology ,Structural basin ,Sedimentary depositional environment ,Fuel Technology ,Source rock ,Geochemistry and Petrology ,Facies ,0202 electrical engineering, electronic engineering, information engineering ,Earth and Planetary Sciences (miscellaneous) ,Oil shale - Abstract
Twenty-four oils produced from the Woodford Shale and overlying Mississippian strata in central Oklahoma were characterized geochemically to determine their possible source(s). The 168 core samples from the Woodford and Mississippian sections of 14 wells in central Oklahoma were initially characterized by total organic carbon (TOC), Rock-Eval, and vitrinite reflectance, and select samples (TOC > 1.0 wt. %) were subjected to biomarker analyses to characterize source input, depositional environment, maturity, and oil-to-source rock correlations. Thermal maturity parameters indicate the Woodford Shale is immature to marginally mature in Payne County, Oklahoma, and shows a progressive increase in maturity toward the southwest. Close to the Nemaha uplift, the Woodford is in the main stage of oil generation. It is proposed that the oils in this area have three possible origins: (1) Oils produced from the Woodford and overlying Mississippian strata have similar fingerprints, suggesting the Woodford Shale and overlying Mississippian strata are in communication; (2) oils produced near the Nemaha uplift (Logan and western Payne Counties) were sourced from the Woodford but had a significant Mississippian source contribution based on source-specific biomarkers; (3) oils east of the Cherokee platform (eastcentral Payne County) share strong Woodford source characteristics, and they were not generated in situ from the immature Woodford Shale but probably migrated from the Woodford Shale in the deeper part of the Anadarko Basin in southern Oklahoma. These results are consistent with the findings that indicate abundant marine coarse-grained biogenic silica (radiolarian-rich) chert facies found in eastcentral Payne County may contribute to good reservoir petrophysical properties, suggesting the Woodford Shale may not be a source in this area but simply a tight reservoir. more...
- Published
- 2019
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7. Re-arranged hopanes and novel re-arranged tricyclic terpanes in Paleozoic rock extracts and oils in the Anadarko Basin, Oklahoma
- Author
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Paul Philp, Matthew Wood, Yagmur Sumer Gorenekli, Thanh Nguyen, Gregory T. Connock, Catherine Pezzaro, Carl Symcox, and Damian Villalba
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Geochemistry and Petrology - Published
- 2022
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8. Kinetic and isotope analyses of tetrachloroethylene and trichloroethylene degradation by model Fe(II)-bearing minerals
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Liang, Xiaoming, Paul Philp, R., and Butler, Elizabeth C.
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- 2009
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9. Geochemical characteristics of saturate hydrocarbons in crude oils and source rocks of the Qaidam, Tarim, Tupran basins, NW China
- Author
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Zhang, Min and Paul, Philp
- Published
- 2012
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10. Organic geochemical characterization of crude oils and source rocks from Concession 6, central Sirt Basin, Libya
- Author
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Richard Paul Philp and Alsharef A. Albaghdady
- Subjects
Total organic carbon ,Maturity (geology) ,chemistry.chemical_classification ,010504 meteorology & atmospheric sciences ,Geochemistry ,chemistry.chemical_element ,010502 geochemistry & geophysics ,01 natural sciences ,Sedimentary depositional environment ,Mediterranean sea ,chemistry ,Source rock ,General Earth and Planetary Sciences ,Organic matter ,Carbon ,Oil shale ,Geology ,0105 earth and related environmental sciences ,General Environmental Science - Abstract
The Sirt Basin contains most of Libya’s producing oil fields and is in northern Libya, south of the Gulf of Sirt in the Mediterranean Sea. The main aims of this study were to characterize the type of organic matter and depositional conditions of the source rocks and thermal maturity of the crude oils in this region using a variety of geochemical techniques including gas chromatography (GC), gas chromatography/mass spectrometry (GCMS), stable carbon and hydrogen isotopes, total organic carbon (TOC), and Rock Eval analysis. Twelve crude oil samples from Cambrian–Ordovician Gargaf, Upper Paleocene Zaltan, and Middle Eocene Gialo reservoirs and seventy-nine source rock samples representing Sirt Shale samples from nine wells were collected from the Zaltan Platform and surrounding troughs in the central Sirt Basin. Organic geochemical parameters indicate that these oils were sourced from marine organic matter deposited under oxic to suboxic conditions. The oils were divided into three groups based on their whole oil carbon and hydrogen isotopic composition and thermal maturity as manifested by several saturate and aromatic hydrocarbon maturity parameters. Based on the geochemical data, it is proposed that there are at least two sources for the crude oils in the Zaltan Platform area of the central Sirt Basin. The study also indicates that the Sirt Shale source rocks from Maradah Trough are dominated by marine organic matter and have reached the main phase of oil generation. more...
- Published
- 2020
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11. Organic geochemistry of the Eagle Ford Group in Texas
- Author
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Andrea A. Miceli Romero, Thanh X. Nguyen, and R. Paul Philp
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Eagle ,020209 energy ,Energy Engineering and Power Technology ,Mineralogy ,02 engineering and technology ,010502 geochemistry & geophysics ,01 natural sciences ,Sedimentary depositional environment ,chemistry.chemical_compound ,Sterane ,Geochemistry and Petrology ,biology.animal ,Organic geochemistry ,0202 electrical engineering, electronic engineering, information engineering ,Earth and Planetary Sciences (miscellaneous) ,Kerogen ,Organic matter ,0105 earth and related environmental sciences ,Total organic carbon ,chemistry.chemical_classification ,biology ,Geology ,Fuel Technology ,chemistry ,Source rock - Abstract
A comprehensive regional organic geochemical study was performed on outcrop and core samples from the Eagle Ford Group with the aim of determining variations in organic matter source, thermal maturity, and depositional environments. Total organic carbon (TOC) and Rock-Eval pyrolysis parameters show that the Eagle Ford Group has excellent hydrocarbon source rock potential and is dominated by type II kerogen. Distributions of regular steranes, hopanes, and monoaromatic steroids confirm a marine carbonate depositional environment. Aryl isoprenoid ratios suggest the occurrence of intermittent photic zone anoxia. The n-alkane and sterane distributions and the presence of pregnanes, homopregnanes, and gammacerane suggest deposition under hypersaline conditions particularly in west and east Texas. In east Texas, biomarkers indicate that the Eagle Ford Group was partially sourced from terrigenous organic matter and deposited under oxic–suboxic conditions. Thermal maturity parameters including the temperature at which the peak corresponding to the compounds produced from the thermal degradation of kerogen in the Rock-Eval chromatogram maximizes (Tmax), vitrinite reflectance, and biomarker ratios indicate that in west and central Texas, the Eagle Ford Group is immature to marginally mature; in southwest Texas it is in the oil to dry gas window; and in east Texas, the Eagle Ford is in the main stage of oil generation. Geochemical logs of biomarker ratios show that the Lower Eagle Ford Formation has the highest TOC and hydrogen index, particularly in the Lozier Canyon Member; experienced stronger anoxic conditions during deposition; and has lower clay content compared with the Upper Eagle Ford Formation. Geochemical parameters show that the latter may have received an additional siliciclastic and terrigenous organic matter input under oxic–dysoxic conditions. Isotope data indicate a marine organic matter source for the Eagle Ford Group, but surprisingly, δ13C values do not show significant organic facies, depositional environment, or thermal maturity variations. more...
- Published
- 2018
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12. ESRD and ESRD-DM associated with lignite-containing aquifers in the U.S. Gulf Coast region of Arkansas, Louisiana, and Texas
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Jeffrey M. Widener, R. Paul Philp, Ann S. Ojeda, and Christopher E. Aston
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Water source ,030232 urology & nephrology ,Water supply ,Aquifer ,Article ,03 medical and health sciences ,Balkan endemic nephropathy ,0302 clinical medicine ,Water Supply ,Diabetes Mellitus ,medicine ,Humans ,030212 general & internal medicine ,Groundwater ,Poverty ,geography ,Arkansas ,geography.geographical_feature_category ,business.industry ,Water pollutants ,Racial Groups ,Public Health, Environmental and Occupational Health ,Louisiana ,medicine.disease ,Texas ,Coal ,Kidney Failure, Chronic ,Water resource management ,business ,Surface water ,Water Pollutants, Chemical ,Poverty level - Abstract
Balkan endemic nephropathy (BEN) is an irreversible, lethal kidney disease that occurs in regions of the Balkans where residents drink untreated well water. A key factor contributing to the development of BEN may be consumption of dissolved organic matter leached from low-rank coal called lignite. This hypothesis—known as lignite-water hypothesis—was first posed for areas of the Balkans. It is possible that a BEN-like condition exists in the United States (US) Gulf Coast region in parts of the Mississippi Embayment and the Texas Coastal Uplands aquifers —Arkansas, Louisiana, and Texas, for instance—that rely heavily on groundwater from aquifers that contain lignite. This study utilizes a geographic information system (GIS) to map the distributions of end-stage renal disease (ESRD) in relation to water from lignite-containing aquifers in the tri-state region. Regional patterns emerged from geospatial analysis, suggesting that counties that relied on lignite-containing aquifers for their main water source had higher rates of ESRD in comparison to other populations in the region that rely on other water sources, including surface water and groundwater from aquifers not associated with lignite seams. Statewide rates of ESRD and diabetes associated ESRD (ESRD-DM) showed strong correlations to the percent of families at or below poverty level and the percentage of African Americans. These confounding factors somewhat mitigate the association seen between ESRD and lignite-containing regions at the state level. However, at the larger tri-state view, there is a significant (p = 0.002) increase in incidence rates where groundwater is connected to lignite-containing aquifers when considering both race and poverty. Additionally, no relationship was observed between the rate of public water supply withdrawal from lignite-bearing aquifers and rates of ESRD or ESRD-DM at the state or tri-state regions, supporting the observation that the risk associated with water from lignite-containing aquifers is limited to water from untreated domestic supply. more...
- Published
- 2018
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13. The development and extent of photic-zone euxinia concomitant with Woodford Shale deposition
- Author
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R. Paul Philp, Gregory T. Connock, and Thanh X. Nguyen
- Subjects
010504 meteorology & atmospheric sciences ,Energy Engineering and Power Technology ,Geology ,010502 geochemistry & geophysics ,Oxygen minimum zone ,Chemocline ,01 natural sciences ,Hopanoids ,Sedimentary depositional environment ,Paleontology ,Sterane ,chemistry.chemical_compound ,Fuel Technology ,Source rock ,chemistry ,Geochemistry and Petrology ,Earth and Planetary Sciences (miscellaneous) ,Photic zone ,Oil shale ,0105 earth and related environmental sciences - Abstract
Understanding the environmental features and processes responsible for the formation of organic-rich, laterally extensive source rocks of appreciable thickness, such as the Late Devonian–Early Mississippian Woodford Shale, is necessary to refine current depositional models. In this study, a detailed assessment of the paleowater column was undertaken via examination of molecular fossil (biomarker) data. Specifically, C40 aromatic carotenoids were used to delineate the nature and severity of photic-zone euxinia concomitant with the deposition of the lower, middle, and upper Woodford. The immature character of the Woodford in the study area ensured that biomarker interpretations were reflective of the depositional environment and not altered by secondary processes. Twenty-nine Woodford Shale samples from the Lawrence uplift of the western Arkoma Basin were subjected to bulk and molecular geochemical analyses, with the objective to enhance the understanding of the paleowater column. A suite of C40 aromatic carotenoids—paleorenieratane, isorenieratane, renieratane, and renierapurpurane—was identified for the first time in the Woodford Shale. Paleorenieratane, the predominant C40 aromatic carotenoid, was found to be isotopically enriched (δ13C e −12‰ ± 1.5‰). This was interpreted as a product of carbon fixation via the reverse tricarboxylic acid cycle, a diagnostic trait of Chlorobiaceae. Additional biomarker parameters sensitive to changes in redox assisted in substantiating interpretations of Chlorobiaceae derivatives, with the severity of photic-zone euxinia inferred by the effects that this environmental state imposed on the overlying microbial community and algal populations. Previously unrecognized inter- and intramember variations in water-column structure and redox state were documented. The lower Woodford was characterized by isolated pulses of photic-zone euxinia, with the middle Woodford deposited during persistent photic-zone euxinia, as evinced by elevated concentrations of the C40 aromatic carotenoids. A deep, persistent chemocline likely typified upper Woodford deposition, but lack of sampling intensity in this member may belie a more episodic nature. Effects of photic-zone euxinia appeared to be most severe in the middle Woodford, where progressively increasing C40 aromatic-carotenoid concentrations coincide with rising gammacerane indices and a systematic decrease in sterane/hopane values. Environmental conditions (e.g., oxygen minimum zone, restriction) that facilitate the development of euxinia in the photic zone were interpreted to reconstruct the paleoenvironment on a local to subregional scale. more...
- Published
- 2018
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14. Biomarkers and Stable Isotopes in Environmental Forensic Studies
- Author
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Paul Philp, R, primary and Kuder, Tomasz, additional
- Published
- 2008
- Full Text
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15. Organic geochemical and paleoenvironmental characterization of the Brown Shale Formation, Kiliran sub-basin, Central Sumatra Basin, Indonesia
- Author
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R. Paul Philp, Thanh X. Nguyen, and Kirellos J. Sefein
- Subjects
chemistry.chemical_classification ,010504 meteorology & atmospheric sciences ,biology ,Structural basin ,010502 geochemistry & geophysics ,biology.organism_classification ,01 natural sciences ,Graben ,Petrography ,Paleontology ,chemistry ,Source rock ,Geochemistry and Petrology ,Group (stratigraphy) ,Botryococcus braunii ,Organic matter ,Oil shale ,Geology ,0105 earth and related environmental sciences - Abstract
The Central Sumatra Basin (CSB), formed during the Late Eocene (?) to Early Oligocene, is the most prolific hydrocarbon basin in Indonesia. The Brown Shale Formation of the Pematang Group is the sole known source rock for the tens of billions of barrels of oil located in the CSB. Samples analyzed in this study were from the Karbindo coal mine in the Kiliran graben of the Kiliran sub-basin, located on the western side of the CSB. This study incorporates advanced organic geochemical and petrographical data of samples from the Brown Shale Formation, as well as interpretations from previous studies at this location, to construct a detailed paleoenvironment model for this Tertiary lake. The lacustrine source rock was deposited under fresh water conditions, with subtle changes in the environment that resulted in significant changes in ecologies. Based on new data from organic petrography, biomarkers, microscale sealed vessel pyrolysis, and characterization of the polyaromatic hydrocarbons, the organic matter in the Brown Shale Formation was determined to be sourced primarily from lacustrine organisms with a small amount of terrestrial plant input. 4-Methylsterane concentrations and n -alkane distributions indicate that non-marine dinoflagellates and Botryococcus braunii (A race) were likely a significant portion of the local biosphere. more...
- Published
- 2017
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16. Composition and Properties of Petroleum
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R. Paul Philp
- Subjects
chemistry.chemical_compound ,chemistry ,Environmental chemistry ,Petroleum ,Composition (visual arts) - Published
- 2020
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17. Possible explanations for the predominance of tricyclic terpanes over pentacyclic terpanes in oils and rock extracts
- Author
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Thanh X. Nguyen, Matthew Wood, Huaida Wang, Dongwon Kim, Carl Symcox, and Paul Philp
- Subjects
Maturity (geology) ,chemistry.chemical_classification ,010504 meteorology & atmospheric sciences ,Geochemistry ,Type distribution ,010502 geochemistry & geophysics ,01 natural sciences ,Hopanoids ,Sedimentary depositional environment ,Source rock ,chemistry ,Geochemistry and Petrology ,Potential source ,Geology ,0105 earth and related environmental sciences ,Tricyclic - Abstract
Hopanes and tricyclic terpanes were identified as the dominant terpanes in crude oils and source rock extracts many decades ago. The majority of terpane fingerprints consist of tricyclic terpanes ranging from C19 to C30 (higher members of the tricyclic terpanes are also present but typically not clearly evident due to the abundance of the hopanes) and hopanes ranging from C27 to C35. Within these two families of terpanes, variations will be observed resulting from factors such as source, depositional environments, maturity, biodegradation and migration. However, the most significant departure from a typical tricyclic and hopane type distribution is one entirely dominated by the tricyclic terpanes with the series extending to at least C40 and in many cases, beyond. There are a few reported occurrences of such distributions in the literature, but satisfactory explanations are limited and speculative. Characterization of numerous oils from Devonian-Mississippian age reservoirs in the STACK play in the Anadarko Basin, Oklahoma, has revealed that many of these oils have terpane fingerprints dominated by tricyclic terpanes with the virtual absence of hopanes. It is also of interest to note that there appear to be four additional series of tricyclic terpanes in many of these samples. While attempting to explain these distributions using previously published arguments, it appears there may be other factors at work leading to the dominance of the tricyclic terpanes in this region. This paper discusses previous explanations put forward to explain these somewhat unusual terpane distributions, followed by a brief discussion of the terpane distributions in the STACK oils. Similar distributions of tricyclic terpanes have also been observed in a number of Mississippian rocks in the region, suggesting a possible source for the tricyclic terpanes in these oils. Results from these rock extracts are integrated into the discussion related to the oils. In summary, it appears that maturity is probably the most significant driving force for these distributions, with preferential production of hopanes over the tricyclic terpanes at lower maturity levels. At the higher levels of maturity experienced by the unconventional reservoirs, only tricyclic precursors remain to generate oils dominated by the tricyclic terpanes. At the same time, potential source contributions cannot be ignored, as shown by the presence of extracts dominated by tricyclic terpanes in many of these core extracts. more...
- Published
- 2021
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18. Origin and history of the oils in the Lawton oil field, southwestern Oklahoma
- Author
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Liu Li, R. Paul Philp, and Thanh X. Nguyen
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Maturity (geology) ,020209 energy ,Geochemistry ,Energy Engineering and Power Technology ,Geology ,Subsidence ,02 engineering and technology ,010502 geochemistry & geophysics ,01 natural sciences ,Petroleum seep ,Paleontology ,Fuel Technology ,Source rock ,Geochemistry and Petrology ,Isotopes of carbon ,0202 electrical engineering, electronic engineering, information engineering ,Earth and Planetary Sciences (miscellaneous) ,Period (geology) ,Oil field ,Oil shale ,0105 earth and related environmental sciences - Abstract
The Lawton oil field is located on the Wichita Mountain uplift in southwestern Oklahoma. This study focused on addressing three problems related to the Lawton oil field: (a) what is (are) the source(s) of the oils; (b) have the oils been subjected to alteration since emplacement; and (c) what is the filling history of the field? Eighteen oils and one seep sample were collected and characterized by a variety of geochemical techniques including bulk composition, biomarkers, and stable carbon isotopes in order to address these questions. Source rocks in this region are absent following the Pennsylvanian-age Wichita orogeny but biomarkers and stable isotopic data suggest the source of these oils is probably the Woodford Shale. Despite the fact that all of these oils were recovered from reservoirs at depths between 125 and 1,000 ft (38 and 305 m), none of them appeared to be extensively biodegraded as manifested by the abundance of the complete range of n-alkanes. However the presence of 25-norhopanes in all eighteen samples suggests that these oils are mixtures of various proportions of degraded and non-degraded (or slightly degraded) oils. The seep sample, and some oils, have a relatively high abundance of the C32 ββ 22R hopanoic acid, relative to the C31 ββ 22R hopanoic acid, with the presence of these ββ 22R hopanoic acids suggesting the oils have been degraded aerobically at some point in their history. It was also noted that the concentration of the C31 ββ 22R hopanoic acid is higher in the shallower reservoirs than in the deeper reservoirs possibly indicating slightly higher levels of degradation in the shallower reservoirs compared to the deeper reservoirs. A hydrocarbon accumulation model has been proposed for this field based on two main reservoir charging periods. The initial charge of crude oil was biodegraded, probably under anaerobic conditions. The second charging period took place after (or together with) the uplift of the Wichita Mountains and subsidence of the southern part of the Anadarko Basin leading to deeper burial of the source rock and production of higher maturity oil, which subsequently filled the reservoirs containing the degraded oil and may still be recharging these shallow reservoirs today. more...
- Published
- 2017
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19. Utility of Compound-Specific Isotope Analysis for Vapor Intrusion Investigations
- Author
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Lila Beckley, Paul Philp, and Thomas E. McHugh
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chemistry.chemical_classification ,Compound specific ,Soil gas ,010401 analytical chemistry ,Sampling (statistics) ,Soil science ,010501 environmental sciences ,Contamination ,01 natural sciences ,0104 chemical sciences ,chemistry ,Vapor intrusion ,Environmental science ,Volatile organic compound ,Groundwater ,0105 earth and related environmental sciences ,Water Science and Technology ,Civil and Structural Engineering ,Isotope analysis - Abstract
Different types of data can be collected to evaluate whether or not vapor intrusion is a concern at sites impacted with volatile organic compound (VOC) contamination in the subsurface. Typically, groundwater, soil gas, or indoor air samples are collected to determine VOC concentrations in the different media. Sample results are evaluated using a “multiple lines of evidence” approach to interpret whether vapor intrusion is occurring. Data interpretation is often not straightforward because of many complicating factors, particularly in the evaluation of indoor air. More often than not, indoor air sample results are affected by indoor or other background sources making interpretation of concentration-based data difficult using conventional sampling approaches. In this study, we explored the practicality of compound-specific isotope analysis (CSIA) as an additional type of evidence to distinguish between indoor sources and subsurface sources (i.e., vapor intrusion). We developed a guide for decision-making to facilitate data interpretation and applied the guidelines at four different test buildings. To evaluate the effectiveness of the CSIA method for vapor intrusion applications, we compared the interpretation from CSIA to interpretations based on data from two different investigation approaches: conventional sampling and on-site GC/MS analysis. Interpretations using CSIA were found to be generally consistent with the other approaches. In one case, CSIA provided the strongest line of evidence that vapor intrusion was not occurring and that a VOC source located inside the building was the source of VOCs in indoor air. more...
- Published
- 2016
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20. The presence of 18α(H)-oleanane in Pennsylvanian and Mississippian rocks in the Anadarko Basin, Oklahoma
- Author
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Paul Philp, Huaida Wang, Thanh X. Nguyen, Yagmur Sumer Gorenekli, Matthew Wood, Carl Symcox, and Dongwon Kim
- Subjects
010504 meteorology & atmospheric sciences ,Structural basin ,010502 geochemistry & geophysics ,01 natural sciences ,Cretaceous ,Paleontology ,chemistry.chemical_compound ,Source rock ,chemistry ,Geochemistry and Petrology ,Pennsylvanian ,Oleanane ,Geology ,0105 earth and related environmental sciences - Abstract
Analyses of multiple Mississippian and Pennsylvanian aged source rock samples in the Anadarko Basin, Oklahoma, revealed the presence of a compound that was tentatively identified as 18α(H)-oleanane. The identity of the 18α(H)-oleanane was subsequently confirmed by GCMS, GCMSMS, and coinjection with a sample known to contain 18α(H)-oleanane. The approach to identifying 18α(H)-oleanane was similar to that described in previous publications that have noted the presence of 18α(H)-oleanane in pre-Cretaceous samples. The presence of 18α(H)-oleanane in an Early Mississippian Kinderhookian sample appears to be the earliest reported occurrence to date. 18α(H)-Oleanane has typically been reported to be derived from a Late Cretaceous/Early Tertiary angiosperm source which would appear unlikely in this case since there are no Cretaceous or Tertiary aged source rocks in Oklahoma. This paper discusses possible sources for 18α(H)-oleanane including the suggestion that angiosperms, or angiosperm related species, split off from the gymnosperms far earlier than previously proposed. It is proposed that the data and methods discussed in this paper clearly show the presence of a compound identified as 18α(H)-oleanane in Mississippian and Pennsylvanian age samples. However, the source of the 18α(H)-oleanane still remains unclear. more...
- Published
- 2021
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21. Biogenic and thermogenic terpenoid hydrocarbons as potential geochemical tools for the study of sedimentary organic matter in subtropical mangrove swamps
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César C. Martins, Richard Paul Philp, and Marina Reback Garcia
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chemistry.chemical_classification ,geography ,geography.geographical_feature_category ,Estuary ,Subtropics ,010501 environmental sciences ,010502 geochemistry & geophysics ,01 natural sciences ,Pollution ,Hopanoids ,Hydrocarbon ,chemistry ,Geochemistry and Petrology ,Environmental chemistry ,Environmental Chemistry ,Sedimentary organic matter ,Environmental science ,Organic matter ,Mangrove ,Bay ,0105 earth and related environmental sciences - Abstract
Terpenoid hydrocarbons are ubiquitous in the marine environment and may be linked to natural synthetic activities after the original carbon skeleton of the biological precursor is retained. The terpenoid profile in pristine environments should have a biogenic signature. However, the widespread use of petroleum-derived products contributes to the inventory of hydrocarbons found in recent sediments, including the introduction of cyclic hydrocarbons with a thermogenic signature. Terpenoid hydrocarbons were examined from the mangrove sediments of the Paranagua Estuarine System (PES), which is a subtropical system in the South Atlantic. Intensive tourism has affected the PES, and it is at high risk of contamination due to extensive urban development and harbour activity. The biogenic compounds (BIO) in the PES were predominantly composed of unsaturated derivatives from higher plants (oleanoids, lupanoids, ursanoids and taraxeroids) with a des-A configuration and bacterial hopanoids. Thermogenic compounds (TRM) were distributed throughout the PES, and the sum of thermogenic and biogenic compounds exhibited a similar distribution, with significant correlations between these compounds. To better assess anthropogenic sources of hydrocarbons in mangrove, a ratio of TRM/BIO was proposed. Ratios higher than 1.0 were found near Paranagua port and in the Paranagua bay area. An important touristic destination, Mel Island, also exhibited ratios higher than 1.0 in two locations. The proposed terpenoids ratio accurately assessed the low-level chronic inputs of anthropogenic hydrocarbons in the study area. This innovative approach may be applied to areas with high biogenic inputs of organic matter, where chronic low-level hydrocarbon contributions are not evident using n-alkanes and polycyclic aromatic hydrocarbons. more...
- Published
- 2020
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22. Applied Petroleum Source Rock Evaluation and High-Resolution Sequence Stratigraphy of La Luna Formation, Venezuela: Integrating for Finding the Unconventional Sweet Spots
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Roger M. Slatt, Andreina Liborius-Parada, and R. Paul Philp
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chemistry.chemical_compound ,Spots ,Source rock ,chemistry ,Geochemistry ,Petroleum ,High resolution ,Sequence stratigraphy ,Geology - Published
- 2019
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23. Heterogeneity of STACK/SCOOP Production in the Anadarko Basin, Oklahoma—Geochemistry of Produced Oils
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Carl Symcox and R. Paul Philp
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Stack (abstract data type) ,SCOOP ,Geochemistry ,Structural basin ,computer ,Geology ,computer.programming_language - Published
- 2019
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24. GEOCHEMICAL COMPARISON OF OILS FROM UPPER PENNSYLVANIAN KANSAS RESERVOIRS, NW KANSAS TO WOODFORD SHALE SOURCE ROCKS: A CASE FOR LONG DISTANCE MIGRATION
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R. Paul Philp and Brittney Lynn Tamborello
- Subjects
Source rock ,Pennsylvanian ,Geochemistry ,Oil shale ,Geology - Published
- 2019
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25. Source Rock of Woodford/Mississippian Tight Oil Play on the Cherokee Platform (Oklahoma) Motivation & Objectives
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Wang, Ting, Liu, Li, Liu, Mu, and R Paul Philp
- Published
- 2019
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26. Carbon Isotope Fractionation of 1,2-Dibromoethane by Biological and Abiotic Processes
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Paul G. Koster van Groos, R. Paul Philp, Sheryl H. Streger, Paul B. Hatzinger, Simon Vainberg, and Tomasz Kuder
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0301 basic medicine ,Abiotic component ,Carbon Isotopes ,Chemistry ,030106 microbiology ,General Chemistry ,Fractionation ,010501 environmental sciences ,Biodegradation ,Chemical Fractionation ,01 natural sciences ,Ethylene Dibromide ,03 medical and health sciences ,Isotope fractionation ,Biodegradation, Environmental ,Isotopes of carbon ,Environmental chemistry ,Environmental Chemistry ,Microbial biodegradation ,Water pollution ,Anaerobic exercise ,Groundwater ,0105 earth and related environmental sciences - Abstract
1,2-Dibromethane (EDB) is a toxic fuel additive that likely occurs at many sites where leaded fuels have impacted groundwater. This study quantified carbon (C) isotope fractionation of EDB associated with anaerobic and aerobic biodegradation, abiotic degradation by iron sulfides, and abiotic hydrolysis. These processes likely contribute to EDB degradation in source zones (biodegradation) and in more dilute plumes (hydrolysis). Mixed anaerobic cultures containing dehalogenating organisms (e.g., Dehaloccoides spp.) were examined, as were aerobic cultures that degrade EDB cometabolically. Bulk C isotope enrichment factors (ebulk) associated with biological degradation covered a large range, with mixed anaerobic cultures fractionating more (ebulk from −8 to −20‰) than aerobic cultures (ebulk from −3 to −6‰). ebulk magnitudes associated with the abiotic processes (dihaloelimination by FeS/FeS2 and hydrolysis) were large but fairly well constrained (ebulk from −19 to −29‰). As expected, oxidative mechanisms fra... more...
- Published
- 2018
27. The Use of the Isotopic Composition of Individual Compounds for Correlating Spilled Oils and Refined Products in the Environment with Suspected Sources
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Paul Philp, R., Allen, Jon, and Kuder, Tomasz
- Published
- 2002
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28. Stable carbon isotopic composition of gasolines determined by isotope ratio monitoring gas chromatography mass spectrometry
- Author
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Smallwood, Barbara J., Paul Philp, R., and Allen, Jon D.
- Published
- 2002
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29. Monitoring In Situ Biodegradation of MTBE Using Multiple Rounds of Compound-Specific Stable Carbon Isotope Analysis
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Tomasz Kuder, Jun Lu, Paul Philp, and Frank Muramoto
- Subjects
geography ,geography.geographical_feature_category ,Compound specific ,010401 analytical chemistry ,Environmental engineering ,Aquifer ,010501 environmental sciences ,Biodegradation ,01 natural sciences ,0104 chemical sciences ,Plume ,In situ biodegradation ,Isotopes of carbon ,Environmental science ,Groundwater ,0105 earth and related environmental sciences ,Water Science and Technology ,Civil and Structural Engineering ,Isotope analysis - Abstract
At a large industrial facility, methyl tert-butyl ether (MTBE) was released to the subsurface and dispersed into the light, non-aqueous phase liquids (LNAPL), in the first aquifer, with the LNAPL serving as a continuous source of MTBE in groundwater. Compound-specific isotope analysis was conducted on both MTBE and tert-butyl alcohol (TBA) in groundwater samples collected in 2008, 2011, and 2013 from wells located along and off the center line of the MTBE plume. The study demonstrated the onset and progress of biodegradation of MTBE between 2008 and 2013. The TBA observed in 2008 appears to be derived only in part from MTBE transformation while a significant portion of TBA might be contributed directly from LNAPL sources. In 2011 to 2013, the dominant source of TBA in the mid-gradient plume was MTBE transformation. A contribution of an offsite LNAPL source, in particular to the down-gradient area of the plume, is possible but could not be unequivocally confirmed. The time series provided direct evidence for MTBE biodegradation, but also a valuable insight on the sources of TBA. more...
- Published
- 2016
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30. Source rock facies distribution predicted from oil geochemistry in the Central Sumatra Basin, Indonesia
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Norelis D. Rodriguez and R. Paul Philp
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Terrigenous sediment ,business.industry ,Geochemistry ,Energy Engineering and Power Technology ,Geology ,Structural basin ,Sedimentary depositional environment ,Graben ,Fuel Technology ,Source rock ,Geochemistry and Petrology ,Facies ,Earth and Planetary Sciences (miscellaneous) ,Coal ,business ,Petrology ,Oil shale - Abstract
The molecular and compound-specific isotopic composition of the n-alkanes in 30 oil samples from the Central Sumatra Basin were analyzed with the purpose of determining facies variations of the source rock in this basin. The oil samples were generated by the Eocene-Oligocene lacustrine Brown Shale Formation. Biomarkers in the oil samples indicate varying contributions from algal and terrigenous organic matter, primarily under oxic, or suboxic depositional conditions. Five source rock facies were identified based on the relative concentrations of n-alkanes, isoprenoids, tricyclic terpanes, and steranes. The individual facies were also distinguished by the compound-specific isotopic composition of the n-alkanes. Source rock depositional environments vary from deep lacustrine, shallow lacustrine, and lacustrine saline to coal and mixed coal and lacustrine shale. Deep lacustrine facies predominate in the Aman and Bengkalis troughs whereas saline and shallow lacustrine facies predominate in the South Aman and Kiri troughs, respectively. Oils derived from coal and mixed coal and lacustrine shale facies predominate in the northern part of the Central Sumatra Basin, in the Tanjung Medan and north of the Balam grabens. more...
- Published
- 2015
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31. Ubiquitous occurrence of high molecular weight hydrocarbons in crude oils
- Author
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Hsieh, Michael and Paul Philp, R.
- Published
- 2001
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32. Fifty Years of Petroleum Geochemistry
- Author
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R. Paul Philp
- Subjects
business.industry ,Oil spill ,Environmental resource management ,Environmental science ,Asset (economics) ,business ,Petroleum geochemistry - Abstract
Any environmental forensic investigation generally revolves around three or four important questions, such as: what is the product; where did it come from; how long has it been there and is it degrading? Many site-or incident-specific factors will determine how these questions are addressed but most will l involve chemical analysis using gas chromatography (GC), GC–mass spectrometry, and stable isotopes. Interpretation of these data for forensic purposes derives from the understanding of oil chemistry, weathering, and naturally occurring organic matter in the environment that exists within decades of petroleum geochemistry literature, which is not commonly used by the majority of environmental investigators but can be very useful in providing additional clues that can be of great use in differentiating oils from different sources. more...
- Published
- 2018
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33. EVOLUTION OF THE LIGNITE-WATER HYPOTHESIS IN THE U.S.: ADVANCES, CHALLENGES, AND THE NEED FOR FUTURE COLLABORATION
- Author
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Ann Sullivan Ojeda and Paul Philp
- Published
- 2018
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34. List of Contributors
- Author
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Puspa L. Adhikari, Matthew Adkins, Joan Albaigés, Hernando P. Bacosa, Gregory Baker, Fred Baldassare, Josep M. Bayona, C.J. Beegle-Krause, Mark J. Benotti, Detlef A. Birkholz, Cornelia Blaga, Chui-Wei Bong, Samantha H. Bosman, Carl E. Brown, Pamela Brunswick, Jeffrey P. Chanton, Elizabeth Chapman, Mei-Hua Chen, Fanny Chever, Jan H. Christensen, Julie Corley, Deborah Crowley, Laura de la Torre, Olívia M.C. de Oliveira, Antônio F. de Souza Queiroz, Majbrit Dela Cruz, Carmen Domínguez, Gregory S. Douglas, William B. Driskell, Stephen Emsbo-Mattingly, Noemi Esquinas, Meredith M. Evans, Nicolas Fitz, James S. Franks, Deborah P. French-McCay, José Luis R. Gallego, Fabiana D.C. Gallotta, A.J. Gravel, Julien Guyomarch, Jeffery Hardenstine, Joshua A. Harrill, Shijie He, Edward (Ted) Healey, Ching-Jen Ho, Bruce Hollebone, Matthew Horn, Wei-Nung Hung, Katherine Jayko, Ronan Jezequel, Paul G.M. Kienhuis, Marcus Kim, John A. Kind, Kerylynn Krahforst, Mette Kristensen, Michael A. Kruge, Christopher L. Kuhlman, Patrick Lambert, Mike Landriault, Azucena Lara-Gonzalo, Stephen R. Larter, Sandra Layland, Lisa Lefkovitz, Yuanwei Li, Zhengkai Li, Danúsia F. Lima, Eric Litman, Bo Liu, Xiaoxing Liu, Zhanfei Liu, Daniel Mendelsohn, Maria de F.G. Meniconi, Buffy M. Meyer, Martin Scott Miles, Glenn C. Millner, Marc A. Mills, Ícaro T.A. Moreira, Paul A. Nony, Thomas B.P. Oldenburg, Gregory M. Olson, Edward B. Overton, Joseph Papineau, Grace Park, James R. Payne, Leo Peschier, R. Paul Philp, Kristoffer G. Poulsen, Jagoš R. Radović, Claudia Y. Reyes, Kelsey L. Rogers, David Runciman, Dayue Shang, Carine S. Silva, Malcolm L. Spaulding, Scott A. Stout, Gordon Todd, Imma Tolosa, Giorgio Tomasi, Vahab Vaezzadeh, Graham van Aggelen, Angela de L.R. Wagener, Chuanyuan Wang, Qing Wang, Zhendi Wang, Shawn M. Wnek, Wendy Wong, Suh-Huey Wu, Chun Yang, Zeyu Yang, Mohamad P. Zakaria, Gong Zhang, and Haijiang Zhang more...
- Published
- 2018
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35. Thiosteranes in samples impacted by fecal materials and their potential use as marker of sewage input
- Author
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Coralie Biache, R. Paul Philp, Amado Enrique Navarro Frómeta, Franciszek Czechowski, Yueming Lu, Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Terre et Environnement de Lorraine (OTELo), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Technol Univ Izucar de Matamoros, Univ Wroclaw, and University of Oklahoma (OU) more...
- Subjects
Irrigation ,010504 meteorology & atmospheric sciences ,Health, Toxicology and Mutagenesis ,Sewage ,Thiosterane ,Wastewater ,010501 environmental sciences ,Toxicology ,Waste Disposal, Fluid ,01 natural sciences ,Feces ,Soil ,Rivers ,Municipal wastewater ,Water Pollutants ,Effluent ,Environmental tracers ,Sterol ,0105 earth and related environmental sciences ,business.industry ,General Medicine ,Pollution ,Anoxic waters ,6. Clean water ,Environmental chemistry ,[SDE]Environmental Sciences ,Sewage sludge treatment ,Environmental science ,Sewage treatment ,Poland ,Stanone ,[SDE.BE]Environmental Sciences/Biodiversity and Ecology ,business ,Sludge ,Environmental Monitoring - Abstract
International audience; Sewage impacted soil, sludge and water samples were studied to understand the occurrence and formation of thiosteranes and to determine the relevance of these compounds as tracers for sewage input into the environment. Soils were collected from wastewater irrigation fields (Wroclaw, Poland), water from the Nexapa River Basin (Mexico), which also received wastewater and wastewater treatment plant (WWTP) effluent, and water and sludge from the Norman WWTP (USA) at different treatment stages. Thiosteranes represented a high proportion of the steroid fraction in the Wroclaw irrigation field and the Nexapa River Basin samples. Small amounts of thiosteranes were found in anaerobically digested sludge from the Norman WWTP. A good correlation between coprostanone and thiosterane concentrations suggests thiosteranes were produced by stanone sulphurization under anoxic conditions. Thiosterane stability under anoxic and suboxic conditions indicates their potential use as tracers for environmental input of sewage products or land application of sewage sludge. more...
- Published
- 2015
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36. Geochemical characterization of the Devonian-Mississippian Woodford Shale from the McAlister Cemetery Quarry, Criner Hills Uplift, Ardmore Basin, Oklahoma
- Author
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Clifford D. DeGarmo and R. Paul Philp
- Subjects
Extinction event ,010504 meteorology & atmospheric sciences ,Stratigraphy ,Geochemistry ,Geology ,010502 geochemistry & geophysics ,Oceanography ,01 natural sciences ,Devonian ,Sedimentary depositional environment ,chemistry.chemical_compound ,Geophysics ,chemistry ,Source rock ,Facies ,Kerogen ,Economic Geology ,Late Devonian extinction ,Oil shale ,0105 earth and related environmental sciences - Abstract
It has been estimated that technically recoverable reserves from shales in the continental U.S. are believed to be approximately 24 billion barrels of oil (BBO) and 750 trillion cubic feet (Tcf) of gas. In Oklahoma the most important hydrocarbon source rock is the Woodford Shale, proposed to be the source of some 70% of the state's liquid hydrocarbon reserves. Such a regionally widespread source rock provides potential for both academic study and industrial opportunities. In this study representative samples of the Woodford Shale from the McAlister Quarry outcrop have been characterized by a variety of geochemical techniques. TOC values range from 0.07 to 15.6 wt% and, based on Rock-Eval Pyrolysis, most of the samples plot within the Type I/II kerogen range, with several low TOC samples plotting in the Type III kerogen range. TOC and biomarker parameters, suggests that two sections of the Upper Woodford are immature paleosols, having been subaerially exposed due to abrupt episodes of sea level fall during the Late Devonian. Evidence for these zones of paleoweathering includes highly depleted TOC, increased oxygen index (OI) values, loss of n-alkanes, decreases in the aryl isoprenoid ratio (AIR), sesquiterpenoids, cheilanthanes, hopanoids, and decreases in many of the polycyclic aromatic hydrocarbons (PAHs). The values of several paleoenvironmental proxies for samples immediately following the Frasnian-Famennian (F–F) Stage extinction boundary within the Upper Woodford suggests that a large influx of weathered terrigenous material occurred at that time. The presence of pyrogenic compounds implies that paleowildfires were widespread throughout the Middle and Late Devonian in the North American midcontinent. It is possible that these influxes of weathered terrestrial organic material stimulated algal blooms that led to the anoxic water column conditions often attributed to the F–F Stage extinction event. Investigation of the stratigraphic framework of these source rocks assists in evaluating their potential as hydrocarbon producers and/or unconventional reservoirs. Integration of geochemical data adds another powerful dimension to this approach. It has been proposed that the Woodford Shale was deposited during a 2nd order depositional sequence. The lower member represented the transgressive systems tract (TST), the Upper member the highstand systems tract (HST), and the Middle member bridging the transition between the two. Numerous 3rd order parasequences were also identified as being part of the overall 2nd order sequence and could be correlated to the Devonian sea level curve. The major objectives of the study were: While this study focuses locally on the McAlister Quarry samples, it is also of regional importance. The Woodford is a prolific source rock throughout the Anadarko Basin and has been the subject of extensive exploration and production efforts, particularly in the past decade with the development of horizontal drilling and hydrofracturing techniques. Continued investigation of the heterogeneity of the shale will greatly enhance the ability to predict more productive facies within the formation throughout the basin. more...
- Published
- 2020
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37. 3D-CSIA: Carbon, Chlorine, and Hydrogen Isotope Fractionation in Transformation of TCE to Ethene by a Dehalococcoides Culture
- Author
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Paul Philp, Tomasz Kuder, Boris M. van Breukelen, and Mindy Vanderford
- Subjects
Dehalococcoides ,Carbon Isotopes ,biology ,Hydrogen ,Inorganic chemistry ,chemistry.chemical_element ,Chloroflexi ,General Chemistry ,Ethylenes ,biology.organism_classification ,Carbon ,Gas Chromatography-Mass Spectrometry ,Trichloroethylene ,chemistry ,Nucleophile ,Isotopes of carbon ,Kinetic isotope effect ,Reductive dechlorination ,Outer sphere electron transfer ,Chlorine ,Environmental Chemistry ,Oxidation-Reduction ,Water Pollutants, Chemical - Abstract
Carbon (C), chlorine (Cl), and hydrogen (H) isotope effects were determined during dechlorination of TCE to ethene by a mixed Dehalococcoides (Dhc) culture. The C isotope effects for the dechlorination steps were consistent with data published in the past for reductive dechlorination (RD) by Dhc. The Cl effects (combined with an inverse H effect in TCE) suggested that dechlorination proceeded through nucleophilic reactions with cobalamin rather than by an electron transfer mechanism. Depletions of (37)Cl in daughter compounds, resulting from fractionation at positions away from the dechlorination center (secondary isotope effects), further support the nucleophilic dechlorination mechanism. Determination of C and Cl isotope ratios of the reactants and products in the reductive dechlorination chain offers a potential tool for differentiation of Dhc activity from alternative transformation mechanisms (e.g., aerobic degradation and reductive dechlorination proceeding via outer sphere mechanisms), in studies of in situ attenuation of chlorinated ethenes. Hydrogenation of the reaction products (DCE, VC, and ethene) showed a major preference for the (1)H isotope. Detection of depleted dechlorination products could provide a line of evidence in discrimination between alternative sources of TCE (e.g., evolution from DNAPL sources or from conversion of PCE). more...
- Published
- 2013
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38. The use of sterol distributions combined with compound specific isotope analyses as a tool to identify the origin of fecal contamination in rivers
- Author
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Coralie Biache, R. Paul Philp, and University of Oklahoma (OU)
- Subjects
Environmental Engineering ,010504 meteorology & atmospheric sciences ,010501 environmental sciences ,Biology ,Mass spectrometry ,01 natural sciences ,Feces ,Rivers ,[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment ,Waste Management and Disposal ,ComputingMilieux_MISCELLANEOUS ,0105 earth and related environmental sciences ,Water Science and Technology ,Civil and Structural Engineering ,Carbon Isotopes ,Isotope ,Ecological Modeling ,Phytosterol ,Phytosterols ,Sediment ,Pollution ,6. Clean water ,Sterol ,Fecal coliform ,Sterols ,13. Climate action ,Isotopes of carbon ,Environmental chemistry - Abstract
The sterol distributions of 9 sediment samples from the Illinois River Basin (OK and AR, USA) were examined in order to identify the source of fecal contamination. The samples were extracted with organic solvent using sonication and the fractions containing the sterols were isolated and analyzed by gas chromatography-mass spectrometry. The sterol distributions of the Illinois River samples were dominated by phytosterols. They were compared to those of different animal feces and manures using a principal component analysis and correspondence appeared between the sediments and one group of chicken feces samples. Gas chromatography-isotope ratio mass spectrometry analyses were also performed to determine the δ(13)C values for the phytosterols and to get an indication of their origin based on the C(3)/C(4) plant signatures. The δ(13)C values obtained ranged from -30.6 ‰ to -17.4 ‰ (VPDB) corresponding to a mixed signature between C(3) and C(4) plants, indicating a C(4) plant contribution to the C(3) plant natural background. These observations indicate that a proportion of the phytosterols originated from chicken feces. more...
- Published
- 2013
- Full Text
- View/download PDF
39. Modeling 3D-CSIA data
- Author
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Mindy Vanderford, Héloïse A.A. Thouement, Tomasz Kuder, Paul Philp, Boris M. van Breukelen, and Philip E. Stack
- Subjects
Halogenation ,0208 environmental biotechnology ,chemistry.chemical_element ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Vinyl chloride ,chemistry.chemical_compound ,Chlorinated ethenes ,Isotopes ,Computational chemistry ,Kinetic isotope effect ,Chlorine ,Reductive dechlorination ,Environmental Chemistry ,Isotopologue ,Groundwater ,0105 earth and related environmental sciences ,Water Science and Technology ,Stable isotopes ,Dehalococcoides ,biology ,Stable isotope ratio ,Chloroflexi ,Ethylenes ,Models, Theoretical ,Reactive transport modeling ,biology.organism_classification ,Carbon ,Trichloroethylene ,020801 environmental engineering ,Kinetics ,Contaminated sites ,Biodegradation, Environmental ,chemistry ,13. Climate action ,Intramolecular force ,Environmental chemistry ,Natural attenuation ,Water Pollutants, Chemical ,Environmental Monitoring ,Hydrogen - Abstract
Reactive transport modeling of multi-element, compound-specific isotope analysis (CSIA) data has great potential to quantify sequential microbial reductive dechlorination (SRD) and alternative pathways such as oxidation, in support of remediation of chlorinated solvents in groundwater. As a key step towards this goal, a model was developed that simulates simultaneous carbon, chlorine, and hydrogen isotope fractionation during SRD of trichloroethene, via cis-1,2-dichloroethene (and trans-DCE as minor pathway), and vinyl chloride to ethene, following Monod kinetics. A simple correction term for individual isotope/isotopologue rates avoided multi-element isotopologue modeling. The model was successfully validated with data from a mixed culture Dehalococcoides microcosm. Simulation of Cl-CSIA required incorporation of secondary kinetic isotope effects (SKIEs). Assuming a limited degree of intramolecular heterogeneity of δ37Cl in TCE decreased the magnitudes of SKIEs required at the non-reacting Cl positions, without compromising the goodness of model fit, whereas a good fit of a model involving intramolecular CCl bond competition required an unlikely degree of intramolecular heterogeneity. Simulation of H-CSIA required SKIEs in H atoms originally present in the reacting compounds, especially for TCE, together with imprints of strongly depleted δ2H during protonation in the products. Scenario modeling illustrates the potential of H-CSIA for source apportionment. more...
- Published
- 2017
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40. Organic Facies
- Author
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R. Paul Philp
- Published
- 2017
- Full Text
- View/download PDF
41. Demonstration of Compound-Specific Isotope Analysis of Hydrogen Isotope Ratios in Chlorinated Ethenes
- Author
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Tomasz Kuder and Paul Philp
- Subjects
Carbon Isotopes ,Chromatography, Gas ,Aqueous solution ,Halogenation ,Compound specific ,Hydrogen isotope ,Radiochemistry ,Uncertainty ,chemistry.chemical_element ,Benzene ,General Chemistry ,Environment ,Ethylenes ,Reference Standards ,Mass Spectrometry ,Dichloroethylenes ,Trichloroethylene ,Chromium ,chemistry ,Isotope Labeling ,Environmental chemistry ,Environmental Chemistry ,Pyrolysis ,Hydrogen ,Isotope analysis - Abstract
High-temperature pyrolysis conversion of organic analytes to H(2) in hydrogen isotope ratio compound-specific isotope analysis (CSIA) is unsuitable for chlorinated compounds such as trichloroethene (TCE) and cis-1,2-dichloroethene (DCE), due to competition from HCl formation. For this reason, the information potential of hydrogen isotope ratios of chlorinated ethenes remains untapped. We present a demonstration of an alternative approach where chlorinated analytes reacted with chromium metal to form H(2) and minor amounts of HCl. The values of δ(2)H were obtained at satisfactory precision (± 10 to 15 per thousand), however the raw data required daily calibration by TCE and/or DCE standards to correct for analytical bias that varies over time. The chromium reactor has been incorporated into a purge and trap-CSIA method that is suitable for CSIA of aqueous environmental samples. A sample data set was obtained for six specimens of commercial product TCE. The resulting values of δ(2)H were between -184 and +682 ‰, which significantly widened the range of manufactured TCE δ(2)H signatures identified by past work. The implications of this finding to the assessment of TCE contamination are discussed. more...
- Published
- 2013
- Full Text
- View/download PDF
42. Carbon Isotope Fractionation in Reactions of 1,2-Dibromoethane with FeS and Hydrogen Sulfide
- Author
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Y. Thomas He, Tomasz Kuder, John T. Wilson, and Paul Philp
- Subjects
Carbon Isotopes ,Ethylene ,Hydrogen sulfide ,Inorganic chemistry ,General Chemistry ,Fractionation ,Chemical Fractionation ,engineering.material ,Ethylene Dibromide ,Kinetics ,chemistry.chemical_compound ,Solubility ,chemistry ,Mackinawite ,Isotopes of carbon ,engineering ,Environmental Chemistry ,1,2-Dibromoethane ,SN2 reaction ,Ferrous Compounds ,Hydrogen Sulfide ,Environmental Restoration and Remediation ,Nuclear chemistry - Abstract
EDB (1,2-dibromoethane) is frequently detected at sites impacted by leaded gasoline. In reducing environments, EDB is highly susceptible to abiotic degradation. A study was conducted to evaluate the potential of compound-specific isotope analysis (CSIA) in assessing abiotic degradation of EDB in sulfate-reducing environments. Water containing EDB was incubated in sealed vials with various combinations of Na(2)S (0.7 mM) and mackinawite (FeS) (180 mM). Degradation rates in vials containing FeS exceeded those in Na(2)S-only controls. In the presence of FeS, first-order constants ranged from 0.034 ± 0.002 d(-1) at pH 6 to 0.081 ± 0.005 d(-1) at pH 8.5. In the presence of FeS, products from reductive debromination (ethylene) and from S(N)2 substitution with S(II) nucleophiles were detected (1,2-dithioethane, DTA). Relatively high yields of DTA suggested that the S(N)2 reactions were not mediated by HS(-) only but likely also included reactions mediated by FeS surface. Significant carbon isotope effects were observed for nucleophilic substitution by HS(-) (ε = -31.6 ± 3.7‰) and for a combination of reductive and substitution pathways in the presence of FeS (-30.9 ± 0.7‰), indicating good site assessment potential of CSIA. The isotope effects (KIEs) observed in the presence of FeS corroborated the predominance of S(N)2 substitution by nucleophiles combined with two-electron transfer reductive debromination. more...
- Published
- 2012
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43. Geochemical characterization of aromatic hydrocarbons in crude oils from the Tarim, Qaidam and Turpan Basins, NW China
- Author
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Min Zhang and Paul Philp
- Subjects
geography ,geography.geographical_feature_category ,Energy Engineering and Power Technology ,Geology ,Phenanthrene ,Structural basin ,Fluorene ,Geotechnical Engineering and Engineering Geology ,Swamp ,Sedimentary depositional environment ,chemistry.chemical_compound ,Geophysics ,Fuel Technology ,chemistry ,Geochemistry and Petrology ,Abundance (ecology) ,Environmental chemistry ,Economic Geology ,Relative species abundance ,Geomorphology ,Naphthalene - Abstract
Based on the systematic study of aromatic hydrocarbons in over 100 crude oil samples collected from the Tabei and Tazhong uplifts in the Tarim Basin, the western depression area in the Qaidam Basin and the Tabei depression in the Turpan Basin, the geochemical characteristics of the marine (Tarim Basin), saline lacustrine (Qaidam Basin), and swamp (Turpan Basin) oils were investigated. The marine oils from the Tarim basin are characterized by relatively low abundance of diaromatic hydrocarbons such as biphenyl and naphthalene, and relatively high abundance of triaromatic hydrocarbons including phenanthrene, dibenzothiophene and fluorene. In contrast, the swamp oils from the Turpan Basin are dominated by the highest relative abundance of diaromatic hydrocarbons and the lowest relative abundance of triaromatic hydrocarbons in all the oil samples in this study. The relative abundance of diaromatic and triaromatic hydrocarbons in the saline lacustrine oils from Qaidam Basin is between that in Tarim oils and Turpan oils. Aromatic parameters based on the isomer distributions of dimethylnaphthalenes (DMN), trimethylnaphthalenes (TMN), tetramethylnaphthalenes (TeMN) and methylphenanthrenes (MP), i.e., 1,2,5-trimethylnaphthalene(TMN)/1,3,6-TMN ratio, 1,2,7-TMN/1,3,7-TMN ratio, (2,6-+2,7-)-dimethylnaphthalenes (DMN)/1,6-DMN ratio, 1,3,7-TMN/(1,2,5- +1,3,7-)-TMN, 1,3,6,7-TeMN/(1,3,6,7- +1,2,5,6- +1,2,3,5-)-TeMN ratio and MP index, may reflect the diversity of organic source input, thermal maturity and depositional environments. In addition, the dibenzothiophenes (DBTs)/fluorenes(Fs) and dibenzofurans (DBFs)/Fs ratios were found to the very useful and effective in determining genetic types of crude oils for the marine, saline lacustrine, and swamp depositional environments, and for oil-oil correlations. more...
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- 2010
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44. Geochemical characterization of gases from the Mississippian Barnett Shale, Fort Worth Basin, Texas
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Norelis D. Rodriguez and R. Paul Philp
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Maturity (geology) ,Energy Engineering and Power Technology ,chemistry.chemical_element ,Mineralogy ,Geology ,Diamondoid ,Methane ,Oil shale gas ,chemistry.chemical_compound ,Fuel Technology ,chemistry ,Geochemistry and Petrology ,Earth and Planetary Sciences (miscellaneous) ,Kerogen ,Hydrous pyrolysis ,Carbon ,Oil shale - Abstract
Molecular and isotopic compositions of 51 gas and 7 condensate samples produced from the Barnett Shale were determined by gas chromatography–isotope ratio mass spectrometry to investigate their origin and maturity at the time of generation. Additionally, two hydrous pyrolysis experiments were performed to calibrate maturity values predicted for gas generation. Molecular and carbon and hydrogen isotopic compositions of the gases indicate that gas produced from the Barnett is thermogenic. To estimate generation maturity, additional analyses were performed on the condensates and available core samples. Diamondoid indices combined with vitrinite reflectance (Ro) measurements, isotopic and molecular composition, and hydrous pyrolysis experiments suggest that gas produced from the Barnett Shale was generated within the condensate–wet gas window (1.3–2.0% Ro) at a later stage than hydrocarbons accumulated in shallower reservoirs. The origin of the gas is thermogenic, probably derived from both kerogen cracking and secondary cracking of previously generated nonmigrated hydrocarbons. Additionally, the occurrence of a methane isotope reversal in group 1 gases corroborates that in-situ oil or gas cracking is occurring in the easternmost part of the study area. more...
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- 2010
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45. Geochemical characterization of solid bitumen in the Chesterian (Mississippian) sandstone reservoir of the Hitch field, southwest Kansas
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Dongwon Kim, Raymond P. Sorenson, and R. Paul Philp
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Paleozoic ,Laramide orogeny ,Geochemistry ,Energy Engineering and Power Technology ,Mineralogy ,Geology ,Fuel Technology ,Source rock ,Geochemistry and Petrology ,Carboniferous ,Clastic rock ,Earth and Planetary Sciences (miscellaneous) ,Ordovician ,Sedimentary rock ,Oil shale - Abstract
Solid bitumen was identified within the Mississippian Chester sandstone reservoir in the Hitch field, southwest Kansas. The adjacent Etzold field has similar reservoir properties but lacks solid bitumen, although the Hitch and Etzold fields were thought to be in pressure communication and have common source rocks. Hitch and Etzold crude oils and core extracts were characterized geochemically to gain a better understanding of the reservoir-filling history and geological and geochemical controls on solid bitumen formation in the Hitch reservoir. Based on a variety of geochemical characteristics, we propose that the Hitch and Etzold oils are mixtures derived from Ordovician and Late Devonian–early Mississippian (Woodford Shale) source rocks. The solid bitumen in the Hitch reservoir probably results from mixing of oils having different geochemical compositions, which filled the reservoir over an extended period. No evidence of severe biodegradation or thermal alteration is observed. A reservoir-filling scenario is proposed in an effort to explain why the Hitch oils are geochemically more heterogeneous than Etzold oils. Furthermore, gas de-asphalting and regional pressure drops as a result of post-Laramide orogeny may have contributed to a phase change in the reservoir fluid and deposition of solid materials by disturbance of thermodynamic equilibrium. The major significance of this study is related to improving our knowledge on the occurrence of the presence of solid bitumen in reservoirs that can introduce barriers into the reservoir, complicating waterflood operations and leading to erroneous oil-in-place calculations and subsequently lower than expected oil recovery. more...
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- 2010
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46. Biodegradation of low-molecular-weight alkanes under mesophilic, sulfate-reducing conditions: metabolic intermediates and community patterns
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Jon Allen, R. Paul Philp, Kristen N. Savage, Lee R. Krumholz, Mostafa S. Elshahed, Victoria A. Parisi, Lisa M. Gieg, and Joseph M. Suflita
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chemistry.chemical_classification ,Ecology ,biology ,Firmicutes ,Fatty acid ,Ribosomal RNA ,Biodegradation ,16S ribosomal RNA ,biology.organism_classification ,Deltaproteobacteria ,Applied Microbiology and Biotechnology ,Microbiology ,Chloroflexi (class) ,chemistry ,Biochemistry ,Sulfate-reducing bacteria - Abstract
We evaluated the ability of the native microbiota in a low-temperature, sulfidic natural hydrocarbon seep (Zodletone) to metabolize short-chain hydrocarbons. n-Propane and n-pentane were metabolized under sulfate-reducing conditions in initial enrichments and in sediment-free subcultures. Carbon isotope analysis of residual propane in active enrichments showed that propane became enriched in (13)C by 6.7 (+/-2.0) per thousand, indicating a biological mechanism for propane loss. The detection of n-propylsuccinic and isopropylsuccinic acids in active propane-degrading enrichments provided evidence for anaerobic biodegradation via a fumarate addition pathway. A eubacterial 16S rRNA gene survey of sediment-free enrichments showed that the majority of the sequenced clones were phylogenetically affiliated within the Deltaproteobacteria. Such sequences were most closely affiliated with clones retrieved from hydrocarbon-impacted marine ecosystems, volatile fatty acid metabolizers, hydrogen users, and with a novel Deltaproteobacterial lineage. Other cloned sequences were affiliated with the Firmicutes and Chloroflexi phyla. The sequenced clones were only distantly ( more...
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- 2010
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47. Biomarkers and compound-specific stable carbon isotope of n-alkanes in crude oils from Eastern Llanos Basin, Colombia
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Jose M. Rincon, José M. Jaramillo, R. Paul Philp, Jon Allen, and Jorge E. Cortes
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chemistry.chemical_classification ,Terrigenous sediment ,Geochemistry ,Geology ,Mass spectrometry ,Cretaceous ,Sedimentary depositional environment ,Paleontology ,chemistry ,Isotopes of carbon ,Organic matter ,Gas chromatography ,Gas chromatography–mass spectrometry ,Earth-Surface Processes - Abstract
Representative samples of crude oils from Cusiana, Cupiagua, Apiay, Castilla and Chichimene fields in the Eastern Llanos Basin of Colombia were analyzed to determine its compound-specific stable carbon isotope composition (CSIA) using gas chromatography–isotopic ratio–mass spectrometry (GC–IRMS). GC–IRMS analyses of n-alkanes allowed differentiating between Cretaceous and Cretaceous/Tertiary oil samples. Cretaceous sourced samples have δ13C-enriched values than Cretaceous/Tertiary sourced samples; the heavier isotope composition of these samples is due to their major terrigenous organic matter input. Their isotope distribution patterns suggest significant algal and/or bacterial contribution (marine origin). The analysis of the n-alkane fractions by GC–IRMS confirms that the organic matter has marine origin in those samples from Cusiana, Cupiagua and Apiay while Castilla and Chichimene have marine origin with terrestrial inputs. The results were confirmed by gas chromatography/FID and gas chromatography/mass spectrometry (GC/MS). Basic geochemical composition show that samples from Cupiagua/Cusiana fields and Apiay/Castilla/Chichimene fields in the Llanos basin, Colombia present different characteristics reflecting a specific for each depositional environment. more...
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- 2010
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48. Effects of Volatilization on Carbon and Hydrogen Isotope Ratios of MTBE
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Jon Allen, Paul Philp, and Tomasz Kuder
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Methyl Ethers ,Pollution ,Air Pollutants ,Carbon Isotopes ,Volatilisation ,Hydrogen ,media_common.quotation_subject ,Soil vapor extraction ,chemistry.chemical_element ,General Chemistry ,Deuterium ,Tritium ,Carbon ,chemistry ,Environmental chemistry ,Environmental Chemistry ,Volatilization ,Gasoline ,Air sparging ,Enrichment factor ,media_common - Abstract
Contaminant attenuation studies utilizing CSIA (compound-specific isotope analysis) routinely assume that isotope effects (IEs) result only from degradation. Experimental results on MTBE behavior in diffusive volatilization and dynamic vapor extraction show measurable changes in the isotope ratios of the MTBE remaining in the aqueous or nonaqueous phase liquid (NAPL) matrix. A conceptual model for interpretation of those IEs is proposed, based on the physics of liquid-air partitioning. Normal or inverse IEs were observed for different volatilization scenarios. The range of carbon enrichment factors (epsilon) was from +0.7 per thousand (gasoline vapor extraction) to -1 per thousand (diffusive volatilization of MTBE from gasoline), the range of hydrogen epsilon was from +7 per thousand (gasoline vapor extraction) to -12 per thousand (air sparging of aqueous MTBE). The observed IEs are lower than those associated with MTBE degradation. However, under a realistic scenario for MTBE vapor removal, their magnitude is within the detection limits of CSIA. The potential for interference of those IEs is primarily in confusing the interpretation of samples with a small extent of fractionation and where only carbon CSIA data are available. The IEs resulting from volatilization and biodegradation, respectively, can be separated by combined carbon and hydrogen 2D-CSIA. more...
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- 2009
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49. Distinguishing Abiotic and Biotic Transformation of Tetrachloroethylene and Trichloroethylene by Stable Carbon Isotope Fractionation
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Elizabeth C. Butler, Yiran Dong, Lee R. Krumholz, Xiaoming Liang, R. Paul Philp, and Tomasz Kuder
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Carbon Isotopes ,Tetrachloroethylene ,Trichloroethylene ,Chemistry ,chemistry.chemical_element ,General Chemistry ,Fractionation ,chemistry.chemical_compound ,Isotope fractionation ,Isotopes of carbon ,Environmental chemistry ,Kinetic isotope effect ,Reductive dechlorination ,Environmental Chemistry ,Carbon - Abstract
Significant carbon isotope fractionation was observed during FeS-mediated reductive dechlorination of tetrachloroethylene (PCE) and trichloroethylene (TCE). Bulk enrichment factors (E(bulk)) for PCE were -30.2 +/- 4.3 per thousand (pH 7), -29.54 +/- 0.83 per thousand (pH 8), and -24.6 +/- 1.1 per thousand (pH 9). For TCE, E(bulk) values were -33.4 +/- 1.5 per thousand (pH 8) and -27.9 +/- 1.3 per thousand (pH 9). A smaller magnitude of carbon isotope fractionation resulted from microbial reductive dechlorination by two isolated pure cultures (Desulfuromonas michiganensis strain BB1 (BB1) and Sulfurospirillum multivorans (Sm)) and a bacterial consortium (BioDechlor INOCULUM (BDI)). The E(bulk) values for biological PCE microbial dechlorination were -1.39 +/- 0.21 per thousand (BB1), -1.33 +/- 0.13 per thousand (Sm), and -7.12 +/- 0.72 per thousand (BDI), while those for TCE were -4.07 +/- 0.48 per thousand (BB1), -12.8 +/- 1.6 per thousand (Sm), and -15.27 +/- 0.79 per thousand (BDI). Reactions were investigated by calculation of the apparent kinetic isotope effect for carbon (AKIEc), and the results suggest that differences in isotope fractionation for abiotic and microbial dechlorination resulted from the differences in rate-limiting steps during the dechlorination reaction. Measurement of more negative E(bulk) values at sites contaminated with PCE and TCE may suggest the occurrence of abiotic reductive dechlorination by FeS. more...
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- 2007
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50. Modern geochemical and molecular tools for monitoring in-situ biodegradation of MTBE and TBA
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Tomasz Kuder and Paul Philp
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Environmental Engineering ,Waste management ,Stable isotope ratio ,Chemistry ,Environmental remediation ,Biodegradation ,Contamination ,Pollution ,Applied Microbiology and Biotechnology ,In situ biodegradation ,Environmental chemistry ,Gasoline ,Waste Management and Disposal ,Groundwater ,Oxygenate - Abstract
Methyl tert-butyl ether (MTBE) is a major gasoline oxygenate worldwide and a widespread groundwater contaminant. Natural attenuation of MTBE is of practical interest as a cost effective and non-invasive approach to remediation of contaminated sites. The effectiveness of MTBE attenuation can be difficult to demonstrate without verification of the occurrence of in-situ biodegradation. The aim of this paper is to discuss the recent progress in assessing in-situ biodegradation. In particular, compound-specific isotope analysis (CSIA), molecular techniques based on nucleic acids analysis and in-situ application of stable isotope labels will be discussed. Additionally, attenuation of tert-butyl alcohol (TBA) is of particular interest, as this compound tends to occur alongside MTBE introduced from the gasoline or produced by (mainly anaerobic) biodegradation of MTBE. more...
- Published
- 2007
- Full Text
- View/download PDF
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