Abstract: Complex Reservoir Geochemistry of the Sleipner Area, Southern Viking Graben, NOCS
Richard Patience, Ger Van Graas, Gary Isaksen
This study was set up to evaluate the existence of different petroleum families in the Sleipner area. Sleipner East (block 15/9) and West (blocks 15/9 and 15/6) are primarily gas/condensate fields, but there is one oil test from the northern part of Sleipner West, as well as oil in a structure (Theta West) to the north of Sleipner East. The sample set includes all available gas, condensate and oil samples from Sleipner West, Dagny (block 15/6), Sleipner East, Loke, Theta West, My and the Alpha structure in block 15/8. Source rock data have also been acquired for the Draupne, Heather, Hugin and Sleipner Formations in the area. The samples have been subjected to the standard suite of geochemical analyses, including carbon isotopes, gas chromatography and gas chromatography- ass spectrometry.
The resulting data set shows the existence of several oil/condensate families, both within and between different reservoir units (Tertiary and Jurassic), which can be related to generation from different source rock types. The gas data also show systematic variations over the area, which do not always match those of the oils/condensates, supportive of multiple sourcing. The gas data indicate, furthermore, different sources for the hydrocarbon gases and for carbon dioxide, which is especially abundant in Sleipner West.
The results from this study can be used both on a reservoir scale, when constructing a reliable model with regard to field compartmentalisation for production purposes, and on a regional scale, when exploring the area for additional petroleum accumulations.
AAPG Search and Discovery Article #90951©1996 AAPG International Conference and Exhibition, Caracas, Venezuela