Abstract: Reservoir Compartmentalization of Deep-Water Intra Qua Iboe Sand (Pliocene), Edop Field, Offshore Nigeria

W. E. Hermance, G. Shanmugam, J. O. Olaifa, E. G. Odior

An integration of 3-D seismic and sedimentological information provides a basis for recognizing and mapping individual flow units within the Intra Qua Iboe (IQI) reservoir (Pliocene), Edop Field, offshore Nigeria. Core examination show the following depositional facies: A- Sandy slump/mass flow, B- Muddy slump/mass flow, C. Bottom current reworking, D- Non-channelized turbidity currents, E. Channelized (coalesced) turbidity currents, F- Channelized (isolated) turbidity currents, G-Pelagic/hemipelagic, H-Levee, I-Reworked slope, J-Wave dominated, and K-Tide dominated facies. With the exception of facies J and K, all these facies are of deep-water affinity. The IQI was deposited on an upper slope environment in close proximity to the shelf edge. Through time, as the shelf e ge migrated seaward, deposition began with a channel dominated deep-water system (IQI 1 and 2) and progressed through a slump/debris flow dominated deep-water system (IQI 3, the principal reservoir) to a tide and wave dominated shallow-water system (IQI 4). Compositional and textural similarities between the deep-water facies result in similar log motifs. Furthermore, these depositional facies are not readily apparent as distinct seismic facies. Deep-water facies A, D, E, and F are reservoir facies, whereas facies B, C, G, H, and I are non-reservoir facies. However, Facies G is useful as a seismically mappable event throughout the study area. Mapping of these non-reservoir events provides the framework for understanding gross reservoir architecture. This study has resulted in seven defin d reservoir units within the IQI, which serve as the architectural framework for ongoing reservoir characterization.

AAPG Search and Discovery Article #90956©1995 AAPG International Convention and Exposition Meeting, Nice, France