The Sleipner effect; a subtle relationship between the distribution of diagenetic clay, reservoir porosity, permeability, and water saturation

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doi: 10.1180/000985500546576
Authors:Nadeau, P. H.
Author Affiliations:Primary:
Statoil, Stavanger, Norway
Volume Title:Mineral diagenesis and reservoir quality, the way forward
Volume Authors:Bain, D. C., editor; Hall, P. L.; Shaw, H. F.; Spears, D. A.
Source:Clay Minerals, 35(1), p.185-200; Sixth Cambridge conference on Mineral diagenesis and reservoir quality, the way forward, Cambridge, United Kingdom, March 26-27, 1998, edited by D. C. Bain, P. L. Hall, H. F. Shaw and D. A. Spears. Publisher: Mineralogical Society, London, United Kingdom. ISSN: 0009-8558
Publication Date:2000
Note:In English. 19 refs.; illus.
Summary:Petrographic, mineralogical and geochemical core analysis of Palaeocene turbiditic sandstones in the Sleipner East gas-condensate reservoirs show the importance of diagenetic clay distribution on porosity, permeability, and water saturation. An observed "high resistivity zone" (HRZ) corresponds to intervals with low water saturation, a more restricted distribution of diagenetic clay (mainly chlorite), and up to 5% quartz cement. The underlying "low resistivity zone" (LRZ) corresponds to intervals with more widely distributed diagenetic clay, which have lower degrees of quartz cementation, higher porosity, and variably reduced permeability. Crosscutting relationships of the HRZ/LRZ with mapped sedimentary depositional units, as well as fluid inclusion analysis data, suggest that the distribution of diagenetic clay was affected by an earlier (late Miocene?) oil charge, and more extensive chlorite formation in a palaeo-water zone. Recent gas condensate charge and structuring of these sandstones resulted in LRZ reservoirs with substantially higher water saturations than those in the HRZ.
Sections:Clay minerals
Subsections:Petrology; weathering; soils
Subjects:Clay mineralogy; Clay minerals; Diagenesis; Distribution; Illite; Oil and gas fields; Permeability; Petroleum; Petroleum engineering; Petroleum exploration; Porosity; Reservoir properties; Reservoir rocks; Saturation; Sheet silicates; Silicates; Smectite; Arctic Ocean; Norwegian Sea; Sleipner Field
Coordinates:N580000 N583000 E0020000 E0010000
Abstract Numbers:01M/124
Record ID:2000057293
Copyright Information:GeoRef, Copyright 2019 American Geosciences Institute.
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