Authority to Prospect (ATP) 743P was granted to Comet Ridge
Limited for a 12 year period, effective from 4 September 2009.
The application was lodged on 18 March 2003 over vacant land.
The initial work program period for ATP743 was from 4 September
2009 to 3 September 2013. 675 sub-blocks were relinquished
on the 3 September 2013.
A special statutory 2 year extension of the initial work program
was applied to ATP 743P. The initial approved work program
was extended until 3 September 2015. 350 sub-blocks or 14
blocks were relinquished on 3 September 2015.
A later work program (LWP) was submitted to the DNRM on 7
July 2015 as part of the requirements for the continuing approval
of ATP 743P. The LWP for ATP 743P was approved on 16 December
2015 for the period 1 November 2015 to 3 September 2019.
Authority to Prospect (ATP) 744P was granted for a 12 year
period, effective from 1 November 2009. The application was
lodged on 18 March 2003 over vacant land.
The initial work program period for ATP744 was from 1 November
2009 to 31 October 2013. 700 sub-blocks or 28 blocks were
relinquished on 31 October 2013.
A later work program (LWP) was submitted to the DNRM on 16
August 2013 as part of the requirements for the continuing
approval of ATP 744P. The LWP for ATP 744P was approved on
22 April 2014 for the period 1 November 2013 to 31 October
A special statutory 2 year extension of the later work program
and relinquishment conditions has been applied to ATP 744P.
The current approved work program and relinquishment condition
has been extended until 31 October 2019.
Comet Ridge holds 100% equity in ATP743 and ATP744.
In July 2012, Comet Ridge announced that it had signed a three-stage
farm-in agreement with Queensland Energy Resources Pty Limited
(QER) to earn up to 75% of a farm-in area, located in the
south east of permit ATP 1015P, adjacent to the Company's
100% held Gunn Project Area in ATP 744P.
The farm-in area consists of two separate
blocks totalling approximately 825 km2. These areas represent
21% of QER's total permit area in ATP 1015P. QER retains a
100% interest in the remaining area of ATP 1015P, while Comet
Ridge has become Operator of the farm-in area.
This transaction creates a continuous acreage
position across a key area in the Galilee Basin, expanding
the Gunn Project Area to the east and allowing it to be appraised
as a single project.
On completion of each stage of the farm-in,
Comet Ridge has the option to proceed with the subsequent
stage. 2 wells, Schmitt-1 and Cernan-1 were drilled in the
Farm-in area in 2012 completing the Stage 1 work programme.
Comet Ridge announced in March 2013 that the Company had elected
to proceed to Stage 2 of the Farm-in by drilling a further
three wells in the Farm-in area. Harringotn-1 well was drilled
in the Farm-in area in mid-2014.
In order to manage cash resources and to ensure focus remains
on the process of achieving reserves in the Mahalo block in
the southern Bowen Basin, in mid-2014 Comet Ridge elected
not to complete Phase II of the ATP 1015P farm-in, which would
have required another two wells to have been drilled at Comet’s
expense. Comet Ridge’s equity in ATP 1015P is currently
being maintained at 20%.
The initial work program period for ATP1015P
was 1 December 2010 to 30 November 2014. A special statutory
2 year extension of the later work program and relinquishment
conditions has been applied to ATP 1015P. The current approved
work program and relinquishment condition has been extended
until 30 November 2016.
COAL SEAM GAS
Prior to the granting of ATP 744P and ATP 743P there had been
little exploration for CSG across the Galilee Basin. CSG evaluation
carried out by Enron in the central part of the basin in the
early 1990’s consistently encountered coal intersections
of 25 to 35m. Gas indications recorded over coal seam intervals
confirmed the presence of gas associated with the coal seams.
The focus of the initial work program for ATP 744P and ATP743P
was to evaluate the CSG potential of the Permian Betts Creek
beds in the Galilee Basin.
Comet Ridge commenced a five-well exploration programme from
late 2009 to mid-2010 to evaluate the CSG potential of the
Betts Creek beds across the two tenement areas. Skiff 1 was
drilled in the north-western portion of ATP743. Montani-1,
Shoemaker-1, Hergenrother-1 and Gunn-1 were all drilled within
ATP744. All wells were fully cored through the Betts Creek
beds to determine key coal properties.
The most promising results were seen at Hergenrother-1 and
Gunn-1 in the south west of ATP 744P where net coals of approximately
16m thickness were intercepted. Gas content, permeability
and gas saturation were most encouraging leading to the definition
of the Gunn Project Area over the south western leg of ATP
The exploration program then focussed on evaluating and delineating
CSG resources and has identified the Gunn Project Area.
255km of 2D land seismic was acquired over the area in mid-2011
to better understand the performance of Gunn-1 and Hergenrother-1
and improve understanding of the structure in the area.
Comet Ridge commenced a three-well exploration and appraisal
drilling programme in late 2012. The first well, Gunn-2 was
drilled to further appraise the coal seams near the offset
well, Gunn-1 in ATP 744P and the following two wells in the
farm-in area, part of ATP 1015P.
The first well, Gunn 2, reached a total depth
of 1,050 metres and intersected 16.2 metres of net coal in
the Betts Creek beds.Wireline conveyed testing tools were
used to flow test four separate coal intervals in the Betts
Creek beds, including two coal intervals in the base of the
section that had not been previously tested in the Gunn Project
Area. All four coal intervals demonstrated good to excellent
The Schmitt 1 and Cernan 1 are both located
in the farm-in area to the east of the Gunn Project area and
were designed to further appraise the Betts Creek beds. Both
wells were fully cored through the Betts Creek beds and intersected
22m and 20.5m of net coal, respectively.
These wells have confirmed the extension of the Gunn Project
Area to the east into the farm-in area. Analysis of the data
indicates that the Gunn Project Area and Farm-in area coals
contain recoverable gas, over an estimated area of approximately
The Schmitt 1 and Cernan 1 wells earned Comet Ridge a 20 %
equity interest in the farm-in area.
An extended production test was completed on Gunn 2 well in
Comet Ridge commenced the drilling of the Harrington 1 appraisal
well in May 2014 in the northern part of the ATP 1015 farm-in
area. The Harrington 1 well reached a total depth (TD) of
1042 m and was cored through the entire Betts Creek beds,
intersecting approximately 19 m of net coal.
Harrington 1 well continues to demonstrate that coals extend
consistently over a wide part of the eastern Galilee Basin.
Comet Ridge continues to hold 20% equity in the Farm-in area
of ATP 1015P, with the remaining equity being held by QER
CSG Pty Ltd.
Gunn 2 Well Extended Production Test
In parallel with the drilling programme, the Gunn
2 well was completed for production in November 2012, with
tubing and a downhole pump installed to enable water to be
produced. During December 2012, surface facilities including
water storage tanks, flowlines, metering facilities and power
generation were installed on site and in early January 2013,
these facilities were commissioned for operation.
The objective of the EPT was to obtain water quality data
and establish connectivity with the coals to enable critical
assessment of the completion methodology providing key design
inputs for a pilot scheme.
The well was perforated over a four metre interval from 952.5
to 956.5 metres which is bounded above and below by impermeable
mudstone. The EPT was designed in this manner to ensure water
would only be produced from the Betts Creek reservoir coal.
By excluding water from other zones in the well, surface water
handling requirements could be optimised and dewatering time
could also be minimised.
The pump and other equipment performed as designed with no
mechanical or electrical issues throughout the test. The water
rate was progressively increased over a period of a few weeks,
with the well reaching a stabilised production rate of approximately
400 bwpd (barrels of water per day) which is the limit of
the pumping system under the current configuration. Analysis
of the pressure data showed that the four metre coal interval,
which was the subject of the test, has even greater flow capacity.
Formation water samples from the coal were taken at regular
intervals for very detailed laboratory analysis.
The progress of the EPT has been extremely
pleasing, with this well an important milestone for the Company
in the Galilee Basin. This is the first test for the Company
on a completed well, where the well has been set up for long
Another very important outcome from the EPT is that the simple
completion style of the well (case, cement and perforate)
has proved to be extremely effective in both connecting the
wellbore to the fractures in the coal and also in isolating
the coal from sandstones. This simple design can subsequently
be applied to a pilot scheme to access selected coals.
The Company is now evaluating different methods of water treatment.
This trial will aid in forming the basis of design for a pilot
scheme in the Gunn Project Area with the intention of achieving
independently certified gas reserves, which would be available
for power generation, LNG manufacture or domestic gas markets.
The highly successful Gunn 2 Extended Production Test (EPT),
which flowed at 400 bwpd (barrels of water per day) led to
the submission of a formal Underground Water Impact Report
(UWIR) to the Department of Environment and Heritage Protection,
as required by legislation under the Water Act 2000 (Qld).
This report was concluded during the December quarter and
released for public review and comment in early January 2014.
The report concluded that the Betts Creek Coal reservoir is
isolated from shallow aquifers that are used for local stock
watering, and due to the impermeable nature of the 300 m thick
Rewan Formation between the shallow aquifers and the Betts
Creek Coals, no impact will be seen in the shallow aquifer
units. The Water Act requires that if there were any impacts,
the Company would need to “make good” any impact
on local farmers through drilling of new water bores, provision
of CSG produced water, or other means.
All landowners in the project area were formally notified
by letter, and notices placed in a local newspaper, as required
by law. In addition, a series of one-on-one meetings were
conducted between the Company and landowners to explain the
formal process required by law, and to run through the conclusions
of the study that was conducted and the content of the UWIR.
CONVENTIONAL - TIGHT GAS
Significant gas potential outside of coal seams exists within
the deeper section, yet to be drilled and tested by Comet
Historical exploration for petroleum in the eastern Galilee
Basin has been sparse and primarily targeted conventional
oil. Three petroleum exploration wells within ATP 743P and
ATP 744P recovered gas and/or oil from sandstone intervals
at the base of the Galilee Basin in the western Koburra Trough.
The source of the hydrocarbons is thought to be in the section
below deeper than the Galilee Basin, which are likely marine
rocks within the basal part of the Drummond Basin sequence
or Devonian aged marine rocks postulated to underlie the Drummond
While there is evidence of an active petroleum system present
over the Koburra Trough, to date no reservoirs have been intersected
of a quality suitable to flow commercial quantities of gas,
even though gas flows at low rates have been observed two
decades ago when the focus was on oil exploration.
Structures are better developed on the eastern side of the
Koburra Trough where Carmichael-1 was drilled (1995), on a
northwest trending structure in the central part of ATP 744P,
to test the petroleum potential of the Lake Galilee Sandstone.
Carmichael--1 discovered a large gas accumulation which was
deemed uneconomic at the time based on test results, however
a recent review of the well data results has indicated that
the productivity of the tight gas reservoir was not optimally
evaluated tested. Recent advances in drilling technology and
changes to the commercial environment suggest that further
evaluation of this gas accumulation is warranted and that
other gas accumulations may be present, given the sparse seismic
coverage in the area.
Carmichael-1 well was drilled in 1995 by Maple Oil & Exploration
NL, as an oil exploration well, to test the petroleum potential
of the Late Carboniferous Lake Galilee Sandstone over a robust
seismically defined anticlinal structure in the then ATP 588P
(now ATP 744P). The structure is approximately 15km long on
its main axis. Three separate zones within the Lake Galilee
Sandstone flowed gas to surface at low rates.
An additional significant section of gas pay was not tested.
The well discovered a large natural gas accumulation which
was deemed uneconomic at the time based on drill stem test
results, and historic very low gas prices, and the well was
plugged and abandoned.
2015 reprocessing and reinterpretation of the seismic data
over the Albany Structure confirmed the presence of a large
anticlinal structure with a significantly larger structural
closure than had been previously mapped. This latest technical
review also indicates Carmichael-1 well was not optimally
located over the crest of the structure, lending to significant
upside for a future appraisal well.
A review of the well data and results has been used to quantify
key reservoir parameters. The well results also indicated
that the productivity of the tight gas formation was not optimally
tested in Carmichael-1 due to the significant overbalance
in mud weight and the presence of liquid hydrocarbons decreasing
relative permeability to gas. Further drilling is required
to test the crest of the structure to demonstrate commercial
flow rates for gas.
The recent prospect review led to an initial
independently certified Contingent Resource Booking for the
Albany Structure of 56PJ 1C, 153PJ 2C and 417PJ 3C, on 5 August
2015. The certification follows an independent review of the
Albany Structure by the certifier SRK Consulting (Australasia)
Pty Ltd. A far as the company is aware this is the first sandstone
gas resource booking in the Galilee Basin and is an important
result for Comet Ridge. Details of the resource certification
are provided in the table below.
This well is close to the Gunn Project Area and demonstrates
further prospectivity in the eastern part of the Galilee Basin.
Comet Ridge is currently assessing potential farm-out opportunities
to drill and test the Albany Structure with the latest drilling
technology and practices.
UNCONVENTIONAL - SHALE OIL/GAS
Further potential exists within source rocks that have generated
the hydrocarbons intersected within the Galilee Basin. The
source of the hydrocarbons is likely to have been generated
from marine rocks within the basal part of the Drummond Basin
sequence or Devonian aged marine rocks postulated to underlie
the Drummond Basin sequence in the Koburra Trough. This sequence
has not been targeted or intersected by exploration drilling
CONTINGENT RESOURCE CERTIFICATION
In late 2010, Comet Ridge announced that Netherland Sewell
and Associates (NSAI) had completed an independent resource
certification for the Gunn Project area in ATP 744P.
In August 2015, Comet Ridge announced that SRK Consulting
(Australasia) Pty Ltd had completed an independent resource
certification of the Albany Structure in ATP 744P.
Note: Gas Reserve and Resource numbers have
been rounded to the nearest whole number.
*ASX Listing Rule 5.28.2 Statement relating to Prospective
Resources: The estimated quantities of petroleum that may
potentially be recovered by the application of a future development
project(s) relate to undiscovered accumulations. These estimates
have both an associated risk of discovery and a risk of development.
Further exploration appraisal and evaluation is required to
determine the existence of a significant quantity of potentially
**Where the auditor has detailed Prospective Resources in
a range, the mid-range case has been listed in the table.
***Resource numbers were previously released under Carmichael
Structure Prospect which has subsequently been re-named Albany