Identification of magnetic enhancement at hydrocarbon/water contacts
Autor: | Adrian R. Muxworthy, A. Fraser, Xiang Zhao, S. A. Badejo, Graham Stevenson, Mike Jackson |
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Rok vydání: | 2020 |
Předmět: |
Greigite
PROTOCOL MIGRATION Iron oxide Energy Engineering and Power Technology Mineralogy Iron sulfide BIODEGRADATION chemistry.chemical_compound Geochemistry and Petrology Earth and Planetary Sciences (miscellaneous) Geosciences Multidisciplinary SIDERITE Magnetite FORC DIAGRAMS Science & Technology Energy GREIGITE Precipitation (chemistry) ORIGIN WESSEX BASIN Geology 0914 Resources Engineering and Extractive Metallurgy Magnetic hysteresis equipment and supplies Magnetic susceptibility Diagenesis OIL-FIELD Fuel Technology chemistry 0403 Geology Physical Sciences REVERSAL CURVE DIAGRAMS human activities |
Popis: | Identifying the depths of the hydrocarbon-fluid contacts in a reservoir is important for determining hydrocarbon reserves and production planning. Using core samples from the Tay Sandstone reservoir in the central North Sea, we show that there is a magnetic enhancement at the hydrocarbon-fluid contacts that is detectable through both magnetic susceptibility measurements and magnetic hysteresis measurements. We observed this magnetic enhancement at both gas-oil and oil-water contacts, which have been independently identified using nonmagnetic methods; we did not consider gas-water contacts in this study. We demonstrate that this magnetic enhancement is caused by the precipitation of new nanometric iron oxide (magnetite) and iron sulfide (greigite) phases. The magnetic enhancement may be caused by diagenetic changes or preferential biodegradation at the top of the oil column during early filling and at the oil-water contact. Our findings have the potential to be used to identify paleo-hydrocarbon-fluid contact in both structurally modified fields and failed wells. The technique can also be used to infer the fill history of a basin and calibrate petroleum systems models. Magnetic susceptibility measurements have the advantage that they can easily and quickly be measured in the field on whole core material. |
Databáze: | OpenAIRE |
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