ABSTRACT: Modeling from
Sunrise to Sunset and back again: Integrated
3-D
reservoir
modeling and
seismic
inversion
studies, Sunrise-Troubadour Field, Timor Sea
Ainsworth, Bruce, Bas Spaargaren, Robert Seggie, Peter Stephenson, David Johnson, Jean-Paul Koninx, and Joe Mcnutt , Woodside Energy Ltd, Perth, Australia
The giant Sunrise-Troubadour gas-condensate field is located in the Timor Sea some 450
km northeast
of Darwin, Northern Australia. Since its discovery in 1974, six wells have
been drilled to appraise the structure: the three most recent date to 1997-98. Middle
Jurassic (Plover Formation) marginal marine sandstones form the main reservoir. The trap
is a broad, approximately 3500 square km, tilted fault block. Information
from
the recent
appraisal campaign has been integrated with a grid (1 x 3 km) of modern 2-D
seismic
data
and together they have been used to formulate field development plans. Description of the
subsurface relies on a range of discrete
3-D
reservoir modeling scenarios which cover the
full spectrum of subsurface uncertainties.
Deterministic and probabilistic modeling of sand and shale bodies has been combined
with statistical seismic
inversion
techniques to determine rock properties (thickness,
net-to-gross, porosity) in the large, greater than 10 km, interwell areas. An iterative
approach was followed whereby depositional geometries
from
initial
3-D
geological models
formed the a priori inputs for the
inversion
runs. The resulting
inversion
property models
were then used to update the
3-D
static geological descriptions before transfer to a
dynamic simulator.
This sophisticated approach draws from
all available geological and geophysical
information, maximizes integration of these disparate
data
types into a coherent static
description of the subsurface, gives confidence to contractible proven gas volumes, and
limits the requirement for further expensive appraisal drilling.
AAPG Search and Discovery Article #90913©2000 AAPG International Conference and Exhibition, Bali, Indonesia