Print this pageCharacterizing Complex Lithology and Architecture of Seismic Volumes of Leveed Channel Reservoirs by Scaled Outcrop Characterization
O. T Ojo1, R. M. Slatt1, A. J. Witten1, S. K. VanDyke2,
M. Burnett3, E. M. Hernandez4, and O. S. Ilaboya1
1 University of Oklahoma, Norman, OK
2 Vanco Energy Co, Houston, TX
3 Fusion Petroleum Technologies Inc, Norman, OK
4 Petroleos Mexicanos,
Seismic volumes of deepwater leveed channel reservoirs in offshore west Africa and Gulf of Mexico reveal considerable internal lateral/vertical complexity. Because of sparse drilling into these deposits, it is only possible to identify lithologic variability at the wellbore. Predictions away from the well bore are uncertain due to this complexity.
This paper provides an example of comparing quantitative outcrop lithology and architecture of a leveed-channel deposit to a subsurface 3D seismic volume of a leveed channel deposit in order to improve lithology and architecture characterization of the seismic volume. The width/thickness of the two deposits are of the same order of magnitude.
The outcrop (Cretaceous Lewis Shale, Wyoming) has been characterized by a combination of GPS mapping, closely spaced measured stratigraphic sections, ground penetrating radar, shallow boreholes, electro-magnetic induction, and high-resolution seismic reflection. It is comprised of nine individual leveed channels confined by a master channel (?) Each internal channel is separated by levees, and levees also occur outside the master channel. The fill of the subsurface master channel (Gulf of Mexico) exhibits fine-scale variability in seismic geometries, as well as internal leveed channels which are similar in complexity and scale to those documented on the outcrop.
This comparison has provided a means of differentiating and modeling the internal distribution of turbidite sands, debrites, slumps, levees and erosional remnants within the master channel from their seismic characteristics. Such comparisons provide a greater level of lithologic and architectural detail than normally obtained for sparsely-drilled leveed channel reservoirs.