Print this pageAn Integrated Reservoir Quality Case Study of Deepwater Lithofacies in the Edop Field, OML 67, Offshore Nigeria
Mustafa A. Jubril1, M. A. Rosin2, A. R. Liesch3, D. Ying4,
M. L. Roth1, M. J. Hayes1, and D. A. DeBram3
1 ExxonMobii Exploration Company, Houston, TX
2 ExxonMobil Development Company, Houston, TX
3 ExxonMobil Production Company, Houston, TX
4 ExxonMobil Upstream Research Company, Houston, TX
The main Edop reservoirs are Pliocene Intra Qua Iboe (IQI) deepwater reservoirs which comprised of three 3rd-order confined to weakly confined slope channel systems (IQI-2, IQI-3, and IQI-4). The IQI-2 and lower part of the IQI-3 are turbidite-dominated, moderate to poorly sorted, medium- to thinly bedded sandstones. The turbidite sands are separated by and/or intermixed with numerous slumps and muddy-sandy debris flows and minor sand injectites. Reservoirs in the upper part of the IQI-3 and IQI-4 are turbidite-dominated, moderate to well-sorted sandstone with fewer slumps and debris flow sediments.
Using data from five cored wells, variations in reservoir quality were identified and quantified, within the lithofacies, stratigraphic, and burial history frameworks at various scales including regional, reservoir, well, and channel complex. Significant variability in reservoir quality (e.g. porosity, permeability) related to the evolution of the channel systems was observed within the IQI reservoirs. Results also indicate that sediment texture, mechanical compaction, and lithofacies are the major controls on reservoir quality distribution.
Compositional and other reservoir quality data from Edop, compared and contrasted with those of downdip Zafiro Pliocene slope channel sediments, suggest differences in their provenance and, possibly, transport histories. Similar textural controls on reservoir quality and distinct porosity and permeability relationships for different lithofacies were established for both Edop and Zafiro.