Evaluation of petroleum heterogeneities in the Eldfish Chalk reservoir using thermal extraction and pyrolysis GC and thermal extraction GC-MS

Conference · Wed Sep 01 00:00:00 EDT 1993 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:7135541

Hall, P B; Bjory, M ^[1]; Stoddart, D; Larter, S R ^[2]; Brasher, J E ^[3]

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1. Geolab Nor A/S, Trondheim (Norway)
2. Univ. of Newcastle, Newcastle upon Tyne (United Kingdom)
3. Phillips Petroleum, Tananger (Norway)

Petroleum geochemical research is being applied more and more to production-oriented problems such as improving recovery of oil from existing fields and identifying satellite fields. Recent studies by ourselves and others have suggested that compositional heterogeneities within the petroleum column of reservoirs can provide information relevant to these objectives. Some of the best data for distinguishing petroleum [open quotes]populations[close quotes] in reservoirs comes from conventional geochemical techniques, some of which are very time consuming (e.g., solvent extraction, EOM fractionation, and GC and GC-MS of saturated and aromatic hydrocarbon fractions). Furthermore, a large number of samples need to be analyzed on order to detect the often slight heterogeneities present in a reservoir. The techniques employed in this study (particularly thermal extraction and pyrolysis GC and thermal extraction GC-MS) can be used to generate large amounts of relevant data quickly. In this study, data were acquired on core samples ([approximately]750) from the Paleocene/Cretaceous Eldfish Chalk reservoir (2/7 block Norwegian North Sea). The acquired data reveal distinct maturity gradients and also small, but still significant, variations in source of the oil within the different Eldfisk oil pools (Alpha, Bravo, and East). This indicates incomplete mixing of the hydrocarbons. These variations have been used to delineate lateral and vertical barriers to petroleum mixing. These observations, when integrated with geological data, can lead to an improved understanding of the possible field filling directions and the intrareservoir compartmentalization. The conclusions from this may also aid in exploration for satellite fields as well as influencing the production plan for the Eldfisk field.

• OSTI ID: 7135541
• Report Number(s): CONF-9310237--
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (United States), Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (United States) Vol. 77:9; ISSN 0149-1423; ISSN AABUD2
• Country of Publication: United States
• Language: English

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