GRIFFIN, ANGELA G., University of Waikato, Department of Earth Sciences, Hamilton, New Zealand
ABSTRACT: High Resolution
Sequence
Stratigraphy Using Geophysical Logs with
Well
-to-
Well
-Outcrop Correlation for Reservoir Delineation in Late Miocene Marine Deposits
The goal of this research project is to develop a wireline-log
model
for the shelf sequences evident in Manutahi-1 (Taranaki Basin), which was continuously
cored, and apply this model to electric logs available for a suite of neighbouring wells,
to better delineate reservoirs in regressive sandstone units.
During the Late Miocene-Pliocene, Taranaki Basin, which is the only hydrocarbon
productive basin in New Zealand, developed a distinct progradational shelf to slope
succession. The Matemateaonga Formation of Late Miocene age beneath Taranaki Peninsula
represents the shelf succession. The formation is characteristically cyclothemic, as shown
by facies analysis
of the continuously cored succession in Manutahi-1. The Manutahi-1 hole
also has a good suite of wireline logs (gamma ray, resistivity, spontaneous potential and
sonic velocity), presenting an opportunity to develop a wireline
log
model for the shelf
sequences defined independently by facies
analysis
.
This project involves high resolution correlation of the wireline logs northward (up
dip) and southward (down dip) from Manutahi;n-1 to neighbouring holes and wells. This will
allow for correlation of the wells at the sequence
and systems tract level. To achieve
this, computer manipulations of digital copies of wireline logs, field
analysis
(lithostratigraphy,
sequence
stratigraphy, facies
analysis
) and computer aided drafting
will be used.
The application of this work relates to subsurface delineation of reservoir units. The
obvious reservoir units are well
-sorted siliciclastic inner to mid shelf sandstone units
that accumulated during the falling stage of sea level cycles (regressive systems tracts).
AAPG Search and Discovery Article #90909©2000 AAPG Foundation Grants-in-Aid