Abstract
This study presents an integrated seismic, well and core-based analysis of the Maureen Formation in the Central Graben of the North Sea. Facies analysis reveals that it is possible to divide the Maureen sandstones into amalgamated, sand- and mud-prone divisions, but that the related chalk facies are complex and imply a range of depositional processes including pelagic fallout, debris flows and turbidity currents. These chalk deposits have an impact on the interpretation of amplitude-based seismic attribute volumes. Detailed petrophysical mapping, supported by seismic analysis, reveals that the Maureen sandstones were deposited in distinct western and eastern fairways controlled by the relict Mesozoic rift topography (although offset stacking is an important intragraben process). The spatial extent of the Maureen sandstones is similar to the overlying Sele and Lista formations and suggests that the broad controls on sediment routing were the same throughout the Lower Palaeogene. Other similarities between these systems include the role of sandstone texture in controlling reservoir quality (although the heterolithic nature of the Maureen sandstones means that porosities and permeabilities are lower). A pattern of intraformational progradation and late-stage backstepping of the sandstone units is likely related to sea-level variability.
| Original language | English |
|---|---|
| Pages (from-to) | 43-62 |
| Number of pages | 20 |
| Journal | Geological Society Special Publication |
| Volume | 403 |
| Issue number | 1 |
| Early online date | 6 Feb 2014 |
| DOIs | |
| Publication status | Published - 2015 |
Bibliographical note
This study was conducted as part of a PhD at the University of Aberdeen on the Maureen and Lista formations of the Central North Sea by B. Kilhams. The project was sponsored by Shell Upstream International (UI) Europe. The authors would like to thank PGS for the use of the UK part of the Central North Sea MegaSurvey, as well as R. Glendinning at BG, A. Carruthers at BP, R. Ings at Maersk Oil and T. Armstrong at Talisman Energy, who granted permissions and organized core-logging sessions. Further Norwegian well-data analysis was completed by E. Colledge as part of her undergraduate final-year thesis at the University of Aberdeen. The work benefited greatly from help and guidance from a large number of staff at Shell UI Europe in Aberdeen and NAM in Assen (including S. Drake, J. Eldrett, S. Inkster, H. Ligtenberg, J. Marshall, T. Mckie, M. Overstolz, C. Papuc, E. Scott, S. Thackrey, J. Volker and P. Watt). Thanks must also go to S. Archer, D. Boyd (Integrated Sedimentology Ltd), D. Healy, D. Hodgson, D. Jolley, I. Kane, B. Kneller, N. Schofield and A. Scott (Iron Mountain) for providing feedback, help and advice at various points in the project. Finally, we would like to acknowledge the reviews of R. Anderton and H. Johnson; their suggestionsgreatly improved the manuscript.