Chemical and isotopic characterization of hydrocarbon gas traces in porewater of very low permeability rocks: The example of the Callovo-Oxfordian argillites of the eastern part of the Paris Basin

Prinzhofer, Alain; Girard, Jean Pierre; Buschaert, Stéphane; Huiban, Y.; Noirez, Sonia

doi:10.1016/j.chemgeo.2008.12.021

Cited by 17 publications

(6 citation statements)

References 26 publications

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“…The alkanes now present in trace amounts in the COx unit have a thermogenic origin and were not generated in the formation itself (Prinzhofer et al, 2009). The various forms of pyrite could be attributed to different reaction pathways.…”

Section: Pyrite Depositionmentioning

confidence: 99%

Mineralogical and isotopic record of biotic and abiotic diagenesis of the Callovian–Oxfordian clayey formation of Bure (France)

Lerouge

Grangeon

Gaucher

et al. 2011

Geochimica et Cosmochimica Acta

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The Callovian-Oxfordian (COx) clayey unit is being studied in the Eastern part of the Paris Basin at depths between 400 and 500 m depth to assess of its suitability for nuclear waste disposal. The present study combines new mineralogical and isotopic data to describe the sedimentary history of the COx unit. Petrologic study provided evidence of the following diagenetic mineral sequence: (1) framboidal pyrite and micritic calcite, (2) iron-rich euhedral carbonates (ankerite, sideroplesite) and glauconite (3) limpid calcite and dolomite and celestite infilling residual porosity in bioclasts and cracks, (4) chalcedony, (5) quartz/calcite. Pyrite in bioturbations shows a wide range of d 34 S (À38& to +34.5&), providing evidence of bacterial sulphate reduction processes in changing sedimentation conditions. The most negative values (À38& to À22&), measured in the lower part of the COx unit indicate precipitation of pyrite in a marine environment with a continuous sulphate supply. The most positive pyrite d 34 S values (À14& up to +34.5&) in the upper part of the COx unit indicate pyrite precipitation in a closed system. Celestite d 34 S values reflect the last evolutionary stage of the system when bacterial activity ended; however its deposition cannot be possible without sulphate supply due to carbonate bioclast dissolution. The 87 Sr/ 86 Sr ratio of celestite (0.706872-0.707040) is consistent with deposition from Jurassic marine-derived waters. Carbon and oxygen isotopic compositions of bulk calcite and dolomite are consistent with marine carbonates. Siderite, only present in the maximum clay zone, has chemical composition and d 18 O consistent with a marine environment. Its d 13 C is however lower than those of marine carbonates, suggesting a contribution of 13 C-depleted carbon from degradation of organic matter. d 18 O values of diagenetic chalcedony range between +27& and +31&, suggesting precipitation from marine-derived pore waters. Late calcite crosscutting a vein filled with chalcedony and celestite, and late euhedral quartz in a limestone from the top of the formation have lower d 18 O values ($+19&), suggesting that they precipitated from meteoric fluids, isotopically close to present-day pore waters of the formation. Finally, the study illustrates the transition from very active, biotic diagenesis to abiotic diagenesis. This transition appears to be driven by compaction of the sediment, which inhibited movement of bacterial cells by reduction of porosity and pore sizes, rather than a lack of inorganic carbon or sulphates.

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Section: Pyrite Depositionmentioning

confidence: 99%

Mineralogical and isotopic record of biotic and abiotic diagenesis of the Callovian–Oxfordian clayey formation of Bure (France)

Lerouge

Grangeon

Gaucher

et al. 2011

Geochimica et Cosmochimica Acta

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“…Although Simpkins and Parkins [], Prinzhofer et al . [], and Clark et al . [] provide insights into the source of CH 4 in a glacial till, sources of isotopically light CH 4 in diffusion‐dominated systems and origin and timing of methane generation in aquicludes, respectively, we are aware of no studies that characterize the distribution, origin, and fate of natural gases in low K argillaceous sediments.…”

Section: Introductionmentioning

confidence: 99%

Fate and transport of dissolved methane and ethane in cretaceous shales of the Williston Basin, Canada

Hendry

Barbour

Schmeling

et al. 2016

Water Resources Research

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Baseline characteristics of dissolved methane (CH4) and ethane (C2H6) and their stable isotopes in thick, low hydraulic conductivity, Cretaceous shales were determined using high‐resolution core profiling at four sites in the Williston Basin (WB), Canada. Positive correlations with the conservative natural tracer Cl− reflected a lack of measureable production or consumption of gases in the shale to the depth investigated (150 m below ground, BG) and suggest CH4 and C2H6 concentrations near the interface with overlying Quaternary sediments are controlled by lateral migration and dilution in permeable zones. Curvilinear increasing concentrations with depth in the shale at all sites coupled with 1‐D solute transport modeling suggest long‐term (over millions of years) upward diffusion of CH4 and C2H6 from deeper WB sources, likely the Second White Speckled Shale Formation (SWSS; ∼790 m BG). δ13C‐CH4 profiles in the shale are consistent with upward diffusional fractionation of isotopes from the SWSS. Distinct CH4 and C2H6 isotope values of gases in the shales versus 13C‐enriched thermogenic isotopic signatures of CH4 and C2H6 in deeper oil‐producing WB intervals could be used to identify fugitive gases originating deeper in the Basin.

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“…But, when monitored in situ, the pCO 2 measurements are not sufficiently accurate for constraining the carbonate system of the geochemical model since they range between 10 -2.5 and 10 -2.1 bar. An alternative experimental procedure for extracting pore waters and their dissolved gases has been used since 2000 in order to determine the content, origins and control processes of dissolved gases in pore water (Lassin et al, , 2003Gaucher et al, 2002Gaucher et al, , 2010Girard et al, 2002Girard et al, , 2005Huiban et al, 2009;Prinzhofer et al, 2009). The extraction procedure is based on outgassing claystone core samples in inert He or Ar gas, combined with analysis of the stable carbon isotopes.…”

Section: Geochemistry Of the Callovian-oxfordian Formation In The Conmentioning

confidence: 99%

Equilibrium partial pressure of CO2 in Callovian–Oxfordian argillite as a function of relative humidity: Experiments and modelling

Lassin

Marty

Gailhanou

et al. 2016

Geochimica et Cosmochimica Acta

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, et al.. Equilibrium partial pressure of CO 2 in Callovian-Oxfordian argillite as a func-tion of relative humidity: experiments and modelling. Geochimica et Cosmochimica Acta, Elsevier, 2016Elsevier, , 186, pp.91-104. 10.1016Elsevier, /j.gca.2016 Accepted Manuscript This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. AbstractHaving previously demonstrated that the mineral assemblage of claystone can impose its pCO 2 under saturated conditions, we here study the effect of rock desaturation, i.e.the evaporation of pore water, on the partial pressure of CO 2 (pCO 2 ) in CallovianOxfordian argillite from the Paris Basin (France). In this new study, which combines experiments at room temperature and geochemical modelling, we examine the primary role of capillary forces on chemical equilibria for relative humidity values ranging between 50% and 100%. In particular we are able, without any fitting parameters, to model the experimental decrease of pCO 2 as a function of decreasing water content in the argillite. This application to a complex natural system not only confirms the theoretical concepts of geochemistry in capillary contexts, but is promising with respect to other systems, both natural (soil, rock) and industrial (ceramics, granular material).

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Chemical and isotopic characterization of hydrocarbon gas traces in porewater of very low permeability rocks: The example of the Callovo-Oxfordian argillites of the eastern part of the Paris Basin

Cited by 17 publications

References 26 publications

Mineralogical and isotopic record of biotic and abiotic diagenesis of the Callovian–Oxfordian clayey formation of Bure (France)

Mineralogical and isotopic record of biotic and abiotic diagenesis of the Callovian–Oxfordian clayey formation of Bure (France)

Fate and transport of dissolved methane and ethane in cretaceous shales of the Williston Basin, Canada

Equilibrium partial pressure of CO2 in Callovian–Oxfordian argillite as a function of relative humidity: Experiments and modelling

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