Stable isotopes of clay minerals from autoclave tests of oil sands : implications for clay formation during steaming of Alberta Clearwater oil sands
In an effort to evaluate mineral-water isotopic exchange during cyclic steam stimulation (CSS), solutions and <2 μm berthierine-dominated solids from the Clearwater Formation oil sands of Alberta, Canada were analyzed for stable isotope compositions before and after reaction in autoclaves for 100...
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sg-ntu-dr.10356-897552020-09-26T21:25:47Z Stable isotopes of clay minerals from autoclave tests of oil sands : implications for clay formation during steaming of Alberta Clearwater oil sands He, Shaoneng Longstaffe, Fred J. Zhou, Zhihong Earth Observatory of Singapore Clearwater Formation Oil Sands Berthierine DRNTU::Science::Chemistry In an effort to evaluate mineral-water isotopic exchange during cyclic steam stimulation (CSS), solutions and <2 μm berthierine-dominated solids from the Clearwater Formation oil sands of Alberta, Canada were analyzed for stable isotope compositions before and after reaction in autoclaves for 1008 hours at 250°C. There was no significant change in solution δ18O and δ2H, which is consisten with the high water/mineral ratio used in the experiments. The solids showed a marked decrease in both δ18O and δ2H following the experiments. Pre-run solids have δ18O of +9.5 to +12.9 ‰ and δ2H of −114 to −113 ‰, whereas post-run solids have δ18O of −4.7 to +2.1 ‰ and δ2H of −147 to −128 ‰. Neither oxygen- nor hydrogen-isotope equilibrium was established between the solids and the solutions. Calculation suggests that oxygen-isotope exchange (44-58%) was greater between the solids and solutions than was the case for hydrogen isotopes (23 to 50 %). We propose that this behaviour resulted from partial inheritance of the pre-run berthierine structure during formation of the post-run smectite, chlorite-smectite and chlorite. This process confounds the use of clay mineral stable isotope compositions as a temperature indicator of in situ steam/steam condensate interaction with oil-sands reservoirs. The results also suggest an additional mechanism by which new clay minerals can be formed during CSS-related, artificial diagenesis. NRF (Natl Research Foundation, S’pore) MOE (Min. of Education, S’pore) Published version 2019-04-25T07:06:46Z 2019-12-06T17:32:45Z 2019-04-25T07:06:46Z 2019-12-06T17:32:45Z 2019 Journal Article He, S., Longstaffe, F. J., & Zhou, Z. (2019). Stable isotopes of clay minerals from autoclave tests of oil sands : implications for clay formation during steaming of Alberta Clearwater oil sands. Applied Geochemistry, 104202-209. doi:10.1016/j.apgeochem.2019.04.001 0883-2927 https://hdl.handle.net/10356/89755 http://hdl.handle.net/10220/48068 10.1016/j.apgeochem.2019.04.001 en Applied Geochemistry © 2019 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license. (http://creativecommons.org/licenses/BY-NC-ND/4.0/). 8 p. application/pdf |
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Clearwater Formation Oil Sands Berthierine DRNTU::Science::Chemistry He, Shaoneng Longstaffe, Fred J. Zhou, Zhihong Stable isotopes of clay minerals from autoclave tests of oil sands : implications for clay formation during steaming of Alberta Clearwater oil sands |
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In an effort to evaluate mineral-water isotopic exchange during cyclic steam stimulation (CSS), solutions and <2 μm berthierine-dominated solids from the Clearwater Formation oil sands of Alberta, Canada were analyzed for stable isotope compositions before and after reaction in autoclaves for 1008 hours at 250°C. There was no significant change in solution δ18O and δ2H, which is consisten with the high water/mineral ratio used in the experiments. The solids showed a marked decrease in both δ18O and δ2H following the experiments. Pre-run solids have δ18O of +9.5 to +12.9 ‰ and δ2H of −114 to −113 ‰, whereas post-run solids have δ18O of −4.7 to +2.1 ‰ and δ2H of −147 to −128 ‰. Neither oxygen- nor hydrogen-isotope equilibrium was established between the solids and the solutions. Calculation suggests that oxygen-isotope exchange (44-58%) was greater between the solids and solutions than was the case for hydrogen isotopes (23 to 50 %). We propose that this behaviour resulted from partial inheritance of the pre-run berthierine structure during formation of the post-run smectite, chlorite-smectite and chlorite. This process confounds the use of clay mineral stable isotope compositions as a temperature indicator of in situ steam/steam condensate interaction with oil-sands reservoirs. The results also suggest an additional mechanism by which new clay minerals can be formed during CSS-related, artificial diagenesis. |
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Earth Observatory of Singapore |
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Earth Observatory of Singapore He, Shaoneng Longstaffe, Fred J. Zhou, Zhihong |
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Article |
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He, Shaoneng Longstaffe, Fred J. Zhou, Zhihong |
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He, Shaoneng |
title |
Stable isotopes of clay minerals from autoclave tests of oil sands : implications for clay formation during steaming of Alberta Clearwater oil sands |
title_short |
Stable isotopes of clay minerals from autoclave tests of oil sands : implications for clay formation during steaming of Alberta Clearwater oil sands |
title_full |
Stable isotopes of clay minerals from autoclave tests of oil sands : implications for clay formation during steaming of Alberta Clearwater oil sands |
title_fullStr |
Stable isotopes of clay minerals from autoclave tests of oil sands : implications for clay formation during steaming of Alberta Clearwater oil sands |
title_full_unstemmed |
Stable isotopes of clay minerals from autoclave tests of oil sands : implications for clay formation during steaming of Alberta Clearwater oil sands |
title_sort |
stable isotopes of clay minerals from autoclave tests of oil sands : implications for clay formation during steaming of alberta clearwater oil sands |
publishDate |
2019 |
url |
https://hdl.handle.net/10356/89755 http://hdl.handle.net/10220/48068 |
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1681056463854764032 |