Redox reactions in hydrocarbon clastic reservoirs: experimental validation of this mechanism for porosity enhancement

Oil-rock-water reactions in hydrocarbon reservoirs were evaluated experimentally. Hematitic Tensleep Sandstone samples of 10–20 cm 3 were heated with 200 ml of deionized water and 100 ml of petroleum for 3–14 days at 200–360°C. The Tensleep Sandstone samples are mature quartz arenites with 5–25% car...

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Bibliographic Details
Published in:Chemical geology Vol. 132; no. 1; pp. 103 - 117
Main Authors: Shebl, M.A., Surdam, R.C.
Format: Journal Article
Language:English
Published: Elsevier B.V 30-10-1996
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Summary:Oil-rock-water reactions in hydrocarbon reservoirs were evaluated experimentally. Hematitic Tensleep Sandstone samples of 10–20 cm 3 were heated with 200 ml of deionized water and 100 ml of petroleum for 3–14 days at 200–360°C. The Tensleep Sandstone samples are mature quartz arenites with 5–25% carbonate matrix and cement and minor amount of anhydrite pore-fillings. Results indicate that significant potential exists for redox reactions between oxidized mineral phases and crude oil. Iron oxides (± sulfate) were reduced and hydrocarbons were oxidized to oxygenated organic compounds (such as CO 2 and organic acids). Organic acids generated during the redox reactions partitioned into the system water, dissolving framework grains and cements (primarily carbonates). Original porosity of the samples ranged from 6% to 15%, and increased by ∼ 13–20%, to 7–18%, or more after experimentation. As reactions between hydrocarbons and mineral oxidants proceed, redox reactions occur, under increasingly reducing condition as temperature increases, and result in enhanced sandstone reservoir porosity.
ISSN:0009-2541
1872-6836
DOI:10.1016/S0009-2541(96)00045-9