Complementary
Structural
Analysis of Channelized Turbidites in the Offshore Niger Delta: Integration of
3-D
Seismic
Data
,
Inversion
of Extra-Deep Azimuthal Resistivity
Data
, Gamma and Density Borehole Images
Abstract
Integration of subsurface geological and petrophysical data
is necessary for a robust
structural
interpretation. Complementary
structural
analysis is a comparative procedure that involves pairing
structural
interpretations
from
two or more sources for improved understanding of subsurface structures. The pairing increases the robustness of any
structural
analysis by providing the geological (type of depositional environment, temporal and spatial considerations) or any other measurement (e.g. tool type, depth of investigation) explanation to support the outcome. In oil field management,
structural
analysis of the reservoir provides invaluable information on subsurface
structural
features (faults, fractures) and reservoir parameters that may impact oil drainage. In this study, a complementary
structural
analysis scheme was
applied
to a Mid- to Late Miocene channelized reservoir in the Niger Delta area. The reservoir consists of several individual turbidite complexes including stacked channels and extensive, lobate sheet sands. Multiple faults, multi-layered, heterogeneous and discontinuous sand bodies are some of the peculiarities of the reservoir and which required characterization for optimum drainage strategy and field management. This case study shows an integrated
structural
interpretation
from
dip measurements derived
from
inversion
of extra-deep azimuthal resistivity
data
, gamma and density images, and 3D
seismic
. This has allowed for a better visualization of the near-wellbore
structural
geology of the wells drilled in the study area, detection of subsurface
structural
features, discontinuities, and the robust determination of key reservoir parameters (reservoir thickness, geometry) of the drilled channelized sand bodies. Our approach also underscored the importance of complementary
structural
analysis in the characterization of channelized turbidites during oil field management.
AAPG Datapages/Search and Discovery Article #90332 © 2018 AAPG International Conference and Exhibition, Cape Town, South Africa, November 4-11, 2018