IN WESTERN AUSTRALIA - Department of Mines and Petroleum

Angel
The Angel field is a gas/condensate discovery
located approximately 50 km east of North Rankin
platform. The discovery is currently being assessed
for future development potential, with the possibility
of development being undertaken for a 2007/08
startup.
Searipple
The Searipple field was discovered in 1996 by the
deepened Perseus 3A appraisal well. Development
plans are in progress in conjunction with the further
development of the Perseus field.
Egret
Egret is a small oilfield approximately 12 km
northwest of the Wanaea field and is currently under
appraisal. The most recent (Egret 3) appraisal well
was drilled in June 2003 finding a gas and oil
column. The decision on future development will be
taken in 2004/05, post acquisition of new seismic.
Dockrell
The Dockrell field is located 6 km southeast of the
Echo/Yodel field and 20 km southwest of the
Goodwyn A platform, in 110 m water depth. The
field was discovered in 1973 by Dockrell 1, which
encountered gross gas and oil columns of 88 m and
14 m respectively, in the Jurassic Brigadier (D Unit)
and Triassic Mungaroo (E Unit) Formations. The
Brigadier Formation is a dominantly shaly interval
with thinly interbedded sands, deposited in a
shallow marine delta front setting. The E Unit is a
high energy, sand dominated, fluvio-deltaic,
sequence. Reservoir units dip towards the northeast
and are truncated by MU. Regionally extensive
Cretaceous shales provide the seal to the
accumulation. Two additional thin hydrocarbon
zones were encountered within Unit F of the
Mungaroo Formation some 300 and 550 m below
the base of the Unit E. Dockrell 2 was drilled in
1998 to test the reservoir units to the north of the
Dockrell field. Two oil-bearing reservoir units, the E
sand (Dockrell 1) and D sand (Dockrell 2), have
been penetrated.
The field is covered by the Keast 3D seismic survey
acquired in 1997, which provided improved
structural and fault definition. Reprocessing of the
Keast 3D data was conducted during 2003.
Timing of the development of the Dockrell field,
which is located within the Goodwyn field
production licence, is dictated by gas supply
demand and is anticipated for a later date.
Development is likely to consist of a sub-sea
development tied-back to GWA.
Keast
The Keast field is located 4 km southeast of the
Echo/Yodel field and 20 km southwest of the
Goodwyn A platform, in 125 m water depth. Keast 1
was drilled in January 1997 and encountered a
gross gas column of 32 m in the Jurassic Unit D
(Brigadier Formation). Gas was also encountered in
Unit E, Intra E, and Lower E sands of the Triassic
Mungaroo Formation. Both the D and E Unit sands
dip northwards and sub-crop below the regional
unconformity (MU). Cretaceous shales above MU
seal the accumulation. The Intra E and Lower E
sands are structurally trapped beneath intraformational
shales.
Unit D is a claystone-dominated interval with
occasional interbedded sands, deposited in a
shallow marine, delta front setting. The E Unit is a
high energy, sand-dominated, fluvio-deltaic
sequence. Unit E sands are thick and are
interpreted to be really extensive. Keast 2 was
drilled in March 1997, to test the hydrocarbonbearing
potential of the Lower Jurassic C Unit and D
Unit to the north. The well intersected a shaly, nonreservoir
D Unit beneath MU. Sands deeper withithe
D Unit, structurally lower than the gas column
encountered in the sub-cropping D Unit at Keast 1,
were water bearing. The current seismic (Keast 3D
survey) provides reliable structural definition and
further improvements may be realised through
interpretation of the Keast 3D reprocessed data.
Development timing for the Keast field, which is
located within the Goodwyn field production licence,
is anticipated at a later date and will be dictated by
gas supply demand. Development will most likely
rely upon a depletion-drive recovery and is likely to
consist of a sub-sea development tied-back to GWA.
Wilcox
The Wilcox field is located approximately 55 km
southwest of the Goodwyn A platform in 70 m water
depth. Wilcox 1 was drilled in March 1983 and
discovered a 500 m gross column within thick
fluvio-deltaic beds of the Triassic Mungaroo
PWA April Edition - 2003 Review 21
Formation. The field lies within a large Triassic fault
block bound to the northwest by a steeply dipping
fault. There are four gas-bearing sands in the E, F,
and G Units. Wilcox 2 was drilled down-flank in
June 1985 to prove additional reserves, but all
sands were found to be water bearing.
First production from Wilcox is not expected until a
later date. Development will most likely rely upon a
depletion-drive recovery and is likely to consist of a
sub-sea development tied-back to GWA.
In 2000, the retention lease WA-7-R was renewed
over the block where the field is located.
Sculptor
The Sculptor field comprises of several fault blocks
and encompasses both the Lower-E and F Units of
the Triassic Mungaroo Formation.
The field is covered by the Keast 3D seismic data,
which was acquired in 1997. A volumetric update to
reflect 3D seismic data was completed during 2002.
Development timing for Sculptor is anticipated at a
later date and will be dictated by gas supply
demand. Development will most likely rely upon a
depletion-drive recovery and is likely to consist of a
sub-sea development tied-back to GWA.
In 2001, the production licence WA-24-L was
granted over the field area thus changing the blocks
status from retention lease (WA-11-R) to production
licence. DoIR
Laying the second trunkline for Burrup gas processing facilities (Image courtesy of Woodside)