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BMR GEOLOGY AND GEOPHYSICS AUSTRALIA
BMR RECORD 1992/45
CARNARVON BASIN (BARROW SUB-BASIN)
GEOCHEMICAL CALmRA TION SURVEY
PROJECT 121.18
G.P. Bickford, D. Heggie, B. Hartman and J. Bishop
t q~~ / 4-)MARINE GEOSCIENCE AND 'PETROLEUM GEOLOGY PROGRAM c.<./-
11111111111 *R9204501*
BMR RECORD 1992/45
CARNARVON BASIN( BARROW
SUB-BASIN) GEOCHEMICAL CALIBRATION
SURVEY
PROJECT 121.18 G.P. Bickfordl , D.Heggie1, B. Hartman2 and J.Bishopl
1 Bureau of Mineral Resources 2 Transglobal Environmental Geoscience
-----BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA -----
DEPARTMENT OF PRIMARY INDUSTRIES AND ENERGY
Minister: The Han. Alan Griffiths
Secretary: G.L. Miller
BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS
Executive Director: R.W.R. Rutland AO
© Commonwealth of Australia, 1992.
This work is copyright. Apart from any fair dealing for the purpose of study, research, criticism, or review, as permitted under the Copyright Act, no part may be reproduced by any process without written permission. Copyright is the responsibility of the Director, Bureau of Mineral Resources.
In reference to digital data these conditions apply to all digital data purchased or acquired, or generated by any subsequent data processing:
1. The purchaser is buying the right to use the digital data, but not the ownership of the data. Ownership of the data remains with the Commonwealth of Australia, which has copyright of the data.
2. All digital data must be kept exclusively for the use of the purchasing company, agency or organisation and must not be transmitted, traded or sold to any third party without the permission in writing of the Executive Director, Bureau of Mineral Resources.
3. An organisation or individual may, with the permission of the Director, reprocess BMR digital data and market products thus derived on a multi-client basis. Generally, the organisation or individual would be required to enter into an agreement with the BMR which would include the following:
a) The Commonwealth will retain copyright of the original data.
b) A copy of the product(s) will be supplied to the BMR.
c) The BMR will claim a licence fee for each copy of the product sold.
d) After a specified period of time the right to copy or sell the product(s) may be exercised by the Commonwealth.
Inquiries should be directed to the Principal Information Officer, Bureau of Mineral Resources, GPO Box 378, Canberra City, ACT, 2601.
ISSN 0811-062 X ISBN 0 642 18250 7
EXECUTIVE SUMMARY ......................................................................................... iii
mTRODUCTION ...................................................................................................... 1 Surface geochemistry and offshore exploration for hydrocarbons ...................... 1 BMR Surface geochemistry overall program objectives .................................... 2
BARROW SUB-BASm: BACKGROUND AND OBJECTIVES ................................ 4
BARROW SUB-BASIN: DHD RESULTS .................................................................. 5 Eastern sector of the Barrow Sub-basin (survey lines Carn 1-3) ........................ 5 Western sector of the Barrow Sub-basin (survey lines Cam 4, 5) .................... 7 Hydrocarbon 'source' ........................................................................................ 8
SUMMARy ................................................................................................................ 9
REFERENCES ........................................................................................................... 11
LIST OF TABLES ...................................................................................................... 12
LIST OF ENCLOSURES ............................................................................................ 15
LIST OF FIGURES .................................................................................................... 16
APPENDIX I ............................................................................................................. .
Carnarvon survey lines 1 through 5 ............................................................................. .
APPENDIX II ............................................................................................................ . DHD METHODOLOGY ................................................................................ .
APPENDIX ill ........................................................................................................... . mTERPRETATIVE METHODOLOGY ........................................................ .
Light Hydrocarbons In Seawater .......................................................... . Data interpretation: the mixing model ................................................. .. Classification of anomalies ................................................................... .
APPENDIX III REFERENCES ................................................................................. .
APPENDIX IV .......................................................................................................... . SYSTEM OPERATIONS REPORT ............................................................... . DHD ............................................................................................................... . NON GEOCHEMICAL SySTEMS ............................................................... .
Enclosure 1 ................................................................................................................ .
Enclosure 2 ................................................................................................................ .
-----BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA n
EXECUTIVE SUMMARY
Transglobal Environmental Geosciences (TEG) and the Bureau of Mineral Resources,
as part of the Joint Research Agreement into hydrocarbon seepage around the
Australian Continental margin, conducted a calibration survey over some known
hydrocarbon accumulations in parts of the Barrow Sub-basin and the Rankin Platform
during 1989. This survey was conducted at the end of a larger and proprietary
geochemical 'sniffer' survey conducted by TEO (for Amoco Production Co., USA) in
the Perth Basin.
Approximately 220 line km of Direct Hydrocarbon Detection (DHD) data were
collected during the survey in the vicinities of known hydrocarbon accumulations,
Saladin, South Chervil, Chervil, North Herald and South Pepper in the inshore part of
the Barrow Sub-basin. Additional survey lines were run in the deeper water part of the
basin, on the landward side of the rift, in the vicinities of Chinook and Griffm, and
further to the north, on the southern extension of the Rankin Platform (Alpha Arch)
over the Gorgon gas/condensate field.
Light hydrocarbon anomalies were detected in bottom-waters in the vicinities of
Saladin, Chervil, South Chervil, North Herald and South Pepper, although the
anomalies were generally weak « five-fold background). No anomalies were detected
near Chinook and Griffin, nor Gorgon, although problems with the tow-cable and tow
fish resulted in the tow-fish being too high above the seafloor to detect any significant
seepage.
iii ------BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA --~~--
INTRODUCTION
Surface geochemistry and offshore exploration for hydrocarbons
The aim of surface geochemical techniques in offshore petroleum exploration is: (a) to
detect direct evidence for thermogenic generation of hydrocarbons in a sedimentary
basin, (b) to assist in locating sub-surface hydrocarbon accumulations, and (c) to
provide information on the likely composition of hydrocarbon accumulations within a
given geologic province. The most common technique used to detect hydrocarbon
seepage offshore involves towing a submerged 'fish' close to the seafloor which
continuously pumps seawater into a geochemical laboratory in the tow-vessel. There,
hydrocarbons are extracted and measured by gas chromatography. This equipment,
commonly known as a geochemical 'sniffer' (Schink et al. 1971; Sigalove and
Pearlman 1975) - or what we refer to as Direct Hydrocarbon Detection (DHD) - has
been widely used overseas for offshore petroleum exploration. InterOcean Systems
Inc., a US-based corporation has collected over 1.5 million line kilometres of data
from about 140 surveys around the world. However, most of the data gathered by
contractors for clients remains proprietary and the opinions expressed publicly, about
surface 'sniffer' geochemical techniques, by the petroleum exploration community
remain divided. Schiener et al. (1985) have commented about the use of the
geochemical 'sniffer' in the North Sea.
Within Australia, the 'sniffer' has been a relatively under-utilised tool in offshore
hydrocarbon exploration, with only four surveys being carried out prior to 1988.
Those surveys were all located in southeastern Australia, specifically in: (1) the
Duntroon Basin, for Getty Oil Development Company Ltd. in 1983, (2) the Otway
Basin (Sprigg 1986) for Ultramar Australia in 1981, and (3) two small surveys in the
Gippsland Basin for Esso Exploration and Production, Australia Inc., in 1983.
------BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA ------
The Bureau of Mineral Resources (BMR), as part of the Continental Margins
Program, and a joint Agreement with Transglobal Environmental Geoscience
(TEG) of Leucadia California (Heggie et al., 1990), has been conducting surface
geochemical (bottom-water DHD and sediment [hydrocarbon-headspace]
geochemistry) surveys on parts of the Australian continental margin since 1989.
Part of this work includes research into:
• the origins (biogenic or thermogenic?) of bottom-water light hydrocarbons
• light hydrocarbon 'sources' (liquids, condensate or gas?)
• bottom-water and seafloor expressions of seepage
• the relationships of seepage to the surface and sub-seafloor geology, including
hydrocarbon accumulations and source rock types and distributions.
BMR Surface geochemistry overall program objectives
The overall objective of the BMR offshore surface geochemistry program is to
evaluate the application of surface geochemical techniques (both direct hydrocarbon
detection (DHD) and sediment [hydrocarbon-headspace] techniques) to hydrocarbon
exploration around the Australian continental margin. Specific objectives include:
• To collect, via reconnaissance surveys, new information on the thermal
generation of hydrocarbons in under-explored Australian basins.
• To test the application of both bottom-water DHD and sediment geochemical
techniques to hydrocarbon prospect ('target') evaluations in both known
hydrocarbon provinces and frontier basins.
• To test, develop and refme criteria to recognise thermally generated migrated
hydrocarbons from background biogenic hydrocarbons in both seawater and
sediments.
------BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA __ ~2,",,--__
• To examine the relationship between hydrocarbon generation and migration by
relating the surface and sub-seafloor expressions of hydrocarbon seeps to the sub
seafloor geology and probable locations and type(s) of source rocks .
• To relate the chemical and isotopic compositions of seeps to 'source'
characteristics, i.e. gas, condensate, liquids, and to predictions from geohistory
and maturation modelling of different source rock types.
• To test bottom-water DHD and sediment geochemistry techniques in the
search for hydrocarbons sealed by stratigraphic traps.
• To examine the biogenic processes influencing the concentrations, distributions
and chemical compositions of hydrocarbon seeps in bottom-waters and the near
surface sediments.
• To examine oceanographic dispersal processes of seeps.
To achieve this, multi-disciplinary programs involving the simultaneous collection of
bottom-water DHD, seismic reflection, gravity, magnetic and side-scan sonar data
have, and will be, carried out by the BMR's research vessel "Rig Seismic" (and
occasionally on other vessels) around the Australian continental margin. These data
are both integrated with each other, and also with sediment geochemical data which
may sometimes be collected during the surveys.
The geochemical analysis system (Direct Hydrocarbon Detection or DHD) that has
been installed aboard the Rig Seismic as part of the Agreement is shown schematically
in Figure II -1 of Appendix II. The laboratory system analyses a variety of gases
extracted from seawater, including CI-C8 hydrocarbons with facilities to collect gases
for shore-based isotopic analyses. Complete details of both the DHD system and the
interpretative methodologies used are given in Appendices II and III.
This BMR Record presents the geochemical data obtained during a very short and very
constrained 'calibration' exercise in the Barrow Sub-basin of the Carnarvon Basin
------BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA ___ -"3~ __
(Fig.1) during July of 1989. These data were obtained by TEG aboard the 'M.V.
Mermaid Searcher', at the completion of a larger, proprietary 'geochemical sniffer'
survey conducted for AMOCO Production Co., in the Perth Basin.
BARROW SUB-BASIN: BACKGROUND AND
OBJECTIVES
Hydrocarbon accumulations in the BarrowlDampier Sub-basins had been, until recently
considered to fall into two trends. There existed an inner trend of oil-prone
hydrocarbon discoveries e.g., Barrow Island and associated accumulations, such as
Saladin, Chervil, North Herald, South Pepper, Harriett, Bambra and Rosette on the
eastern flank of the Barrow Sub-basin, while an outer trend of predominantly
gas/condensate accumulations were associated with the western side of the Barrow
Sub-basin along the Rankin Trend e.g., Gorgon, West Tryall Rocks. However, more
recently, there have been oiVgas discoveries in the what had previously been
considered gas/condensate-prone areas, eg Griffin and Chinook, Wanaea and Cossack.
Given the occurrences of gas/condensate and oiVgas accumulations within the Barrow
Sub-basin and the distinction between the inner oil-prone and outer gas/condensate
trends becoming blurred, it was considered that surface geochemical techniques,
specifically DHD (geochemical 'sniffer'), could be a useful complementary exploration
tool that may be used to distinguish gas from oil prone accumulations, and hence
reduce exploration risk in this part ofthe North West Shelf.
The objectives of this survey therefore were to; (i) measure the concentrations of light
hydrocarbons in the bottom-waters of the Barrow-Sub-basin, in areas of known
hydrocarbon (both gas/condensate and oiVgas discoveries) accumulations, hence (ii) to
______ BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA ___ 4.:.-. __
evaluate the potential application of bottom-water geochemical data in new exploration
on the N orth-West Shelf.
BARROW SUB-BASIN: DHD RESULTS
Bottom-water geochemical data were collected along five survey lines (Figs. 1 and 2).
These lines (Carn 1, Carn 2, Carn 3, Cam 4, Cam 5) are presented in this record as
both the individual lines and also as a composite line in Figure 13. The corresponding
shot-point numbers and line numbers of the composite data set are shown in Table 1.
The geochemical analysis system used to acquire the bottom-water light hydrocarbon
data is identical to that installed on the Rig Seismic and is described in Figure 11-1,
Appendixll.
Eastern sector of the Barrow Sub-basin (survey lines Carn 1-3)
Line summary plots of light hydrocarbons are shown in Figures 3 through 9. Line
summary plots of total hydrocarbons (THC; Fig. 3), sum CI-C4 (Fig. 4) and the
individual saturated hydrocarbons methane (Fig. 5), ethane (Fig. 6) and propane (Fig.
8) show similar trends: bottom-water anomalies were found on survey lines Carn 1 and
Carn 2, in the eastern part of the survey area.
All anomalies are weak (generally less than five-fold typical background
concentrations), but nevertheless are clearly distinguishable from the local background
hydrocarbon concentrations. Methane concentrations are highest in the anomalies on
line Carn 2, and increase from background of about 3.5 ppm to about 9 ppm (Fig. 5).
------BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA __ ---'5:::...-__
Similarly, ethane concentrations increase about five-to-ten-fold above background
levels in the anomalies measured on lines Carn 1 and 2 (Fig. 6). Maximum ethane was
measured at about 0.1 ppm, typically, 0.04 - 0.08 ppm (typical background about 0.01
ppm). The increases in ethane are not accompanied by corresponding increases in the
unsaturated biogenic hydrocarbon (ethylene) (Fig. 7). Propane concentrations varied
similarly to ethane, but propane only showed minor increases above local background.
For example, in the strongest anomaly on line Carn 2, propane increased to levels
typically 0.025 to 0.05 ppm, and the local background was about 0.015 ppm (Fig. 8).
Propylene concentrations (biogenic hydrocarbons) were relatively high on lines Carn 1
and Carn 2 (Fig. 9).
The anomalies are also reflected in the line summary plots of the Bernard parameter
(methane/(ethane+propane) Fig. 10); the ratio of methane/ethane (Fig. 11), variations
in the ethane/propane ratio (Fig. 12), and variations in the % hydrocarabon wetness
(Fig. 14). It should be noted that the sudden increase in wetness on survey line Cam 5
results from the rapid appearance of iso-butane and trace levels of propane, but no
increases in methane and ethane, and is not believed to be seepage from the seafloor
(see below).
The positions of the anomalies are summarised in Table 2. The anomaly on survey line
Carn 1 (Appendix I), corresponds closely to the location of the Saladin 1 oil and gas
field. The anomalies on line Carn 2 (Appendix I), correspond closely to the
accumulations of South Chervil and Chervil oil and gas fields, while the northernmost,
and very weak anomaly corresponds to the North Herald and South Pepper oil and gas
condensate accumulations.
At a ship speed of about 5 knots, the anomalies measured on Carn 1, near Saladin
(Appendix I) could be detected over distances of about 17 km, those anomalies near
South Chervil and Chervil, over distances of about 5 km each, while that near North
------BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA ___ 6~ __
Herald and South pepper, about 6 -7 Ian (Appendix I). During this part of the survey,
the tow-fish was consistently at an altitude of about 10 m above the seafloor (Fig.13).
At the end of the survey line Carn 2, a transit line (Carn 3) was run westward toward
the Chinook and Griffm oil and gas/condensate accumulations (Fig. 2). No anomalies
were found on this line although it did not pass near any known accumulations, and the
tow-fish altitude was more than 20 m above the seafloor (SP 324 to 462; Fig. 13).
Western sector of the Barrow Sub-basin (survey lines Cam 4, 5).
Survey line Carn 4 was designed to test for seepage near Chinook and Griffm. No
anomalies were found possibly because the tow-fish (due to mechanical problems with
the winch and cable) was at an altitude of 30 - to - 40 m above the seafloor for much
of this line (sp 463 to 529; Fig. 13), at a total water depth of about 140 to 168m.
Geochemical data collection was commenced again further to the north near Spar 1,
and passed over the Gorgon gas/condensate field, and continued to survey near to
West Tryall Rocks. No anomalous concentrations of CI-C3 hydrocarbons were
detected, although elevated iso-butane concentrations were found (SP 38-90;
Appendix I), which persisted for a distance of about 12 Ian, near Central Gorgon and
North Gorgon. These result in a sudden increase in wetness values on Carn 5 (Fig. 14).
However, for much of this part of the survey, continued mechanical problems with the
winch (App. IV) resulted in the tow-fish being more than 40 m above the seafloor
(Fig. 13), and these instantaneous appearances of anomalous levels of i-butane (which
are not accompanied by increases in methane or ethane although trace increases in
propane were found, Figs. 5, 6 and 8), are probably not related to seepage. Time
constraints meant these survey lines could not be re-run. Because of the unusual
elevation of the tow-fish above the seafloor in these sectors (Carn 4 and 5) of the
survey, the lack of bottom-water anomalies is inconclusive as a calibration exercise.
------BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA ___ ..:...7 __
Hydrocarbon 'source'
The molecular compositions of the anomalies may provide some clues to the potential
'source' (liquids, condensate or 'dry' (biogenic or thermogenic) gas). According to the
cross-plot model of Figure III-I, Appendix III, potential liquid-prone accumulations
are indicated by increasing hydrocarbon wetness values with increasing methane
concentrations. Gas/condensate sources are reflected in near constant hydrocarbon
wetness values with increasing methane while 'dry' gas is indicated by decreasing
wetness values with increasing methane.
In the anomalies found during this survey, methane co-varies with both ethane (Fig.
15) and propane (Fig. 16), although the propane increases above background represent
only trace amounts. In the plot of percent hydrocarbon wetness versus line number
(Fig. 14), typical background wetness values are < 1 %. Increases in wetness values (up
to about 2%) are associated with the anomalies near Saladin, S. Chervil, Chervil and
N.HeraldlS.Pepper. Wetness values increases rapidly to above 2 % in the southern part
of line Cam 5, but these are associated with the unexplained appearance of i-butane
when the tow-fish was high in the water column (above).
The cross-plot of methane versus percent wetness (Fig. 17) shows two trends of
increasing wetness with increasing methane. The trend of increasing wetness at
background methane (3 ppm, closed squares) is associated with the iso-butane
increases on Cam 5 (propably not related to seepage). However, the trends on
increasing wetness with increasing methane are associated with the bottom-water
anomalies near Saladin, South Chervil, Chevil and North HeraldiSouth Pepper. These
are expanded in Figure 18, which shows the data separated by survey line. Background
data are indicated by the transit line (Cam 3, closed squares); data from Cam 1, near
Saladin (closed diamonds) and data from Cam 2 (S.Chervil, Chervil and
N.HeraldlS.pepper, open squares). The data from line Cam 2 are shown in Figure 19,
------BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA ___ -loS"--__
and indicate separate trends for South Chervil (sp 1-35, closed squares); Chervil 1-3
(SP 36-98, open squares and closed diamonds), and for N.Herald/S.Pepper (SP 99-
182, open diamonds). However, because of the generally low concentrations of all
hydrocarbons measured during the survey (methane increases only about two-fold
above background) and wetness values increase about twice background, these trend
lines are not strongly developed. However, they do indicate trends of varying wetness
with increasing methane, which are at least qualitiatively consistent with the oil/gas
nature of these accumulations.
SUMMARY
Approximately 220 line km of bottom-water light hydrocarbon data were collected
from the Barrow Sub-basin of the Carnarvon Basin during July 1989. The survey was
limited in scope, and intended as a brief calibration exercise only, to test the potential
application of DHD ('geochemical sniffer') techniques to new exploration in this area.
The survey was conducted by TEO (with BMR participation) aboard the vessel M.V.
Mermaid Searcher.
Light hydrocarbon CI-C3 anomalies were detected in bottom-waters in the vicinity of
the Saladin, South Chervil, Chervil and N.Herald/S.Pepper oil and gas/condensate
accumulations. Because these anomalies were detected close to the seafloor, they
probably represent hydrocarbon seepage from the subsurface into the overlying
bottom-waters. These anomalies were weak, but could be detected over distances of
about 5 - 20 km.
A cross-plot of methane versus percent hydrocarbon wetness indicates small increases
(about double) in wetness for increases (about threefold) in bottom-water methane
concentrations. At these low hydrocarbon concentrations this cross-plot model, used
------BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA ___ -=9:.....-__
as a rapid guide to potential hydrocarbon 'source', is not very sensitive. However, the
model does distinguish the Saladin, South Chervil and Chervil, and the
N.HeraldlS.Pepper accumulations. The cross-plot model suggests the anomalies are
sourced from liquids, or gas/condensate hydrocarbon accumulations.
------BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA ___ ;;;.;10"--__
REFERENCES
Heggie, D.T., Falvey, D.A. and Hartman, B. (1990), Joint geochemical Research: An
Agreement between the Commonwealth of Australia and Transglobal Exploration and
Geoscience (USA). Bureau of Mineral Resources Record 1990174.
Scheiner, E.I, Stober, G. and Faber, E. (1985), Surface geochemical exploration for
hydrocarbons in offshore areas - principles, methods and results. In: Thomas, B.N.
etal. (eds), Petroleum geochemistry in exploration of the Norwegian Shelf. Norwegian
Petroleum Society, Graham and Trotman Ltd, London, 223-38.
Schink, D.R., Guinasso Jr, N.L. Sigalove, IJ. Cima, B.E. (1971), Hydrocarbons under
the sea - a new survey technique. In: 3rd Annual Offshore Technology Conference
Houston, Texas OTC 1339, 1-15.
Sigalove, J.J. and Pearlman, M.D. (1975), geochemical seep detection for offshore oil
and gas exploration. In: 7th Annual Offshore Technology Conference Houston, Texas,
OTC 2344, 95-100.
Sprigg, R.C. (1986), A history of the search for commercial hydrocarbons in the
Otway Basin complex. In: Glenie, R.C.(ed.), Second South-Eastern Australia Oil
Exploration Symposium. Petroleum Exploration Society of Australia, 173-200.
11 ------BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA ----..;:~--
LIST OF TABLES
Table 1. Shot-point numbers and survey line names for the composite data ftle and
reference to Figure 13.
Table 2. Bottom-water anomalies and locations of hydrocarbon accumulations.
12 ------BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA ----==---
Table 1. Shot-point numbers and survey line names refering to the composite data set
shown in Figure 13.
Shot-point Line name
1-140 Carn 1
140-322 Carn2
323-462 Carn3
463-529 Carn4
530-767 Carn 5
------BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA __ ---::;1.:::,3 __
Table 2. Bottom-water anomalies and locations of hydrocarbon accumulations.
Survey line Anomaly (sp:lat;long) Accumulation (lat;long)
Carn 1 sp 74: 21.4605; 115.1540 21.4416; 115.0531
spI25:21.4775;115.0830
Carn2
Carn2
Carn2
sp 37: 21.3745;115.2100
sp 50: 21.3487;115.2063
sp 69: 21.3319; 115.2297
sp 84: 21.2733;115.2250
21.3444;115.2033
21.3036; 115.2258
sp 122: 21.1330;115.2605 21.1762;115.2674
sp 140: 21.0687;115.2365 21.1249;115.2747
Name
Saladin-l
S.Chervill
Chervil-l
N.Herald-l
S.Pepper-l
-----BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA ___ 1;;\,.;;4~_
LIST OF ENCLOSURES
Enclosure 1: Floppy disk with ASCII files of geochemical data
Enclosure 2: Map showing DHD survey lines
------BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA __ --=10.:;;,5 __
LIST OF FIGURES
Figure 1. Map of the survey area showing geochemical survey lines and arrows to
represent anomalies.
Figure 2. Map of the survey area showing geochemical survey lines and locations of
select wells on the North West Shelf.
Figure 3. THC versus survey line number.
Figure 4. Sum C1-C4 saturated hydrocarbons versus survey line number
Figure 5. Methane versus survey line number.
Figure 6. Ethane versus survey line number
Figure 7. Ethylene versus survey line number.
Figure 8. Propane versus survey line number.
Figure 9. Propylene versus survey line number.
Figure 10. Bernard parameter versus survey line number.
Figure 11. Methane/ethane versus survey line number.
Figure 12. Ethane/propane versus survey line number.
^BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA^16
Figure 13. Fish altitude versus shot-point.
Figure 14. Percent hydrocarbon wetness versus survey line number.
Figure 15. Methane versus ethane, all survey lines.
Figure 16. Methane versus propane all survey lines.
Figure 17. Methane versus percent hydrocarbon wetness for all survey lines.
Figure 18. Methane versus percent hydrocarbon wetness for survey lines Cam-1, 2,3.
Figure 19. Methane versus percent hydrocarbon wetness for survey line Cam-2.
17BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA
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~------BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA -------
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------- BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA -------
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L I aterimitELTIP1.1111• • Fa • VI
^1 0.00^ IL■111■ 1 1Li ^•
1 • I.^II -^iirPi6-1 117 it.rerwrini n„,.^m
N to INa W
I
cn 8.00 —^
.00., 0 •Uv^• ill mil:IP a
i Itn ,•
•• on ,. FR -^••P.^le4 il•^• •
1 pii! 7r747061
tjrr■F4gl• p
C^...1•71 - ..rowittipr dog, r
• ra_ L,
eO 1, nogrire-firArrougha,,,,,- roar err rt,r,peaTri ,^ing,I ,PilIII11111rJO0 r 7-1^
ri. bwrisl.
Or I. p •asO Lel^
LFILVIrtillargrairll IN 1106
^
i.L. VErlim^Lelt.- 111115,
2 6.00 —^ .13›..I
ECLCL
4.00 —
2.00 —
^0.00 ^
ctsEC 0-) (v) 1.r) Lc)
as(1:3^0C 3^61 3^0(^0C^C'^0
▪^
16^L-6^S
12.00 —
Figure 3. 'THC versus survey line number.
6.0000
10.000
9.000
8.000
7.000
C12
5.000
4.000 J
^
3.000 ^
2.000
1.000
^
0.000 ^
4.
I^1^1^1^I^I^I^I^1111 1
friteritagoiX
EL II^F-4
Tiff milititilLPITIVS*Attirr I. AL liwom
ted•
C1-C4 v. Line number
(.4^ N-3^,R1-•^ LL--)^Lr>^1176_^6_C7^ C,
C.>^C.,^L.>^L.>^ 7->^C.>^ C.>^C.7^Cl^C.>^C>
Figure 4. Sum C1-C4 saturated hydrocarbons versus survey line number
?1J-rkirr Pir4 . e
Iss^rrorra4.11i
traurreAsrivaog■-
Tomirigarl rr.reirefedrargidfell
Methane v. Line number
9.00
8.00
7.00
6.00
-151 5.00CY0
2:7
K. 4.00
3.00
2.00
1.00
0.00 I 1^1^I^1I^I^I^I^II^I^ICV^ tr,^LC)
•^
u-)^kr)- C7^C7^
•^
C7^7=7^C7C-7^ C-7^ C.7^C-7^C-7^ C-7^C-7^ C-7^C-7^4-7^C-7
Figure 5. Methane versus survey line number.
14% ukto
Ethane v. Line number
0.100
0.090
•
•0.080
•0.070
0.060
0.050
cm_0,- 0.040
0.020
0.010
0.030
I.IIIII • ill
i a • IIk • •'iim •
IN 1k
P INII 1 pi .• 1 MI
I I
• r ••bI
ill^k v •
• •^L 'IN•I^1^II
^
/^I N.^iji goAir.^Iffir^•
* bho^1 I Sink• 16^V P IN Oink^w IMP.
lh ji Ill•1^Ir Ir.
^
IIIIIk•^O PrllittloIP1m^
im IFOLI
•
YR PM^ !Visor sr a^PA
Wk.^ • igtornaim us Fri! PP pT l• WHOP •111111V1110^ Ilk1111160 i •Ib Toper mos h• P• • • 1011,11P1•11r. IP116 ■Ir••PIO^ •
Mill I. Pk. IIIIPPACI■ 44101112 WirallA irelealgiPitilAbit^• •^ rpp s,...Mk. PIIP-III•PAN VELIN INN Iila 11105•11. , • PO i
• k III Mkt^k IN^lalh^• IRO., 1 MP 1/11• RP • IP a. IIP . Cry!' rarnrIllonahlfflii...P• PPIPIOPIIIIINPICIP PIIIIr•P•tim MIMI. WIMP. , k Iiii■11.•••IIVIPIN PIP , •III4■■ 101r. PPIlirr•IiII116•111111111110111- Willis I•^Illk l•WIIIIIIIMIkallii • IPsfilikblIk. IN lila Inkk
^
OE^ •
0.000 I I^I^I^I^I^I^I^I^I^I^I^I^ICJ
C.> C-7
Figure 6. Ethane versus survey line number
Ethylene v. Line number
0.120
CNI CNA
C.)
_u") Lc)
1prr-ram• , ilrerno •fa, • a. • • a.^•^• ri iiihirirriffilPia 61411"rlit'&01-101.11 !• ki•
•IA 61 1;•••kit ,y •er 45.irdit Jr I I dim •IL^WitiiIN
.6 ill ilk^%nal^• • II^. ,Qr LA: •
NE •• •• r-• rr^*r,
0.1 00 -I Lei leP. PIrli • • Tim •
Tor 1 • ...Ir. •• 1.5.^ii . . Ws * .'qra,, 1
,. ir • ii pigin•L NI. • era'qpip . .7.,.. • INle^If p i11 •he 1 111.011060.080^'-riti r kii my- • • Lima -titre 1 Ims r di II Ir. II Ilk I • II
^
1^1 • 1111• iii Mill p^PI'rill I Iiiiril iril. II1. • _ Lii„.2 1„,...
^
'II.^ . ... •., • .1. it
• • rP
I.- rim& IlL iris. •ro 911.1111 — rilualm. •^W^"I" •Ir-^r r •Ns -r
*m-t.a.141. •^m,^• a be II •
• • •
Ng•1^—^i411009,.trrot^OWirT^r 171% Ell O1^WO. I^r--.•o • 'Fool •^1•11111167grVP^-11-1. A^k—.
, I^• •1:11 • iv Term. „7„ MrilleafrafarrfillittO;^r
gg^•^ •0111-.4% • tirww,
0.040
0.020
0.000
Figure 7. Ethylene versus survey line number.
• Nall
11 1=
C-) C-3
Cs)
S_)
C`.1
C.)
N.)
I^11a
iii nil•
tv*,Il It *IN II^ •
^1 1 I^I^1*^as Iv^7 •^atrara NI^II •^111
• a
• AN NI IN um I • •• ai^• "Pt 7^:IF^•
^I (alit^• Pot• •1^tamp 111p• 7 .1 •Likibq i^I Fault? i
•0 .1•11111 §^154:114NA Mil N 111 win
• at• •
ki.4111 •^• III•"%a intaTii: a • fsisilta)
f^ViiiirtoP#10• arum )^liarityCips
^
fp • j al^lif *rani
^
I Nap la^or ita•
Propane v. Line number
0.050
0.045
0.040
0.035
o: 0.030c.
..„,e 0.025
cm-cL 0.020
0.015
0.010
0.005
0.000
Figure 8. Propane versus survey line number.
Propylene v. Line number
0.060
•0.050
•0.040 •IR •mot
IA. 1 • II^WIPIE• II • Pa 10110 • inwit. limn • • li 0,11,10 Ails!
Omit^: Nam, com,..,,D•1 •NIB [ii ii ID, • 1 lions, • 1NE immorn,^• II U •^•• •IiIIiuN^I 41
IN is^• • •
III^•IP^I^1, • 0^I
• • II mi^*0• 1•11**N0 NA um
• i•ommunimmil OM
^
I^11.1 ill •^• 11 I!'!.l•om
n0 1 1 um!.
^
II•^II NIIIVi• I V411100*^1• 11 •^ii III•11•^• I Mill III^• 1111••
•
•
• •
• •• PP
U .
^m I pm !Wm II ism^• • 1 I EL mom Illmml• • IA^I^• ••
• l••1 11411^II
^P ^s6 ill
• 1 I fin • •• 1.• 1 iliT • j•
MI I^PP^I I 1111•110.14••• IP HP* I PlIIPM A I • • • ll Will^II I^. um Iil
^
I^Imtolt lumHIPP I^PI 11•11 2 I NM I i 1011 .. No PIIIPIINI I IM II AM • III NI I^Il• NI^11•11111111••fit• l•
1OPPI1
• ullslomm• I Imo. • ••••• INN mipm• tiV • OH mi...• piimmmusimim im Iwo^i. a1PPIIIP •PPRIPI II PUMP 111 W It ll•I i 1 PI PIO 11011PRIP• WIMP PP •OI 1••••••• 1 Dm I anom 1 AI I il • • II • mil mom um • I mum 111111^IV I fit r• •,1••• Ion^•DI 1 r• • km^1 l• I.^• I• •^m• Mt mom II Mg I • 01^• •
• • I^I •^ EA.•• • •• •^•^ nii
COI0
0.030
eL
0.020
nol ip^•^•
•• Al^717 •
0.010
0.000
1 1^1
1^1^1
I^I^I^I^I^I^I^I^I
CNJ C`L.1 C".1 N) 1.0 LC)L._
Figure 9.9. Propylene versus survey line number.
Bernard Parameter v. Line number
C-7
CVJ
C-7 C-7
CV! Cc"
C7
17,-)
C-,
LC) LC)
L-C7C-7
LC) LC) Lf)
250.000
200.000
150.000
ce.j
100.000
50.000
0.000
•1III 11 1411 '1111. 7:1 ,: win ION rig,0 11 4 4" •"1 frit„.^1 II
Ft!.^ra•1117 1 a^'rail •I. .iv 1:17011.111r. pripm ' 11 il ill WO Teal '
aki,11 s L Re . qj all -1 W-1 11-19
• I I aiii 0^
Ni71 t•2.... b ,I !Ill.,.
11 1I in ell^ is^-i.a
0 •w.1 Ili^*al ir i n,c.•^i ll
^Il l °el^Ca V •
jairgton 616
^
I^i^1
111^it=^..-- b.um
^1 1^v irimII•i•
il tolilt^ II ?I itIra il^• ja i• trift. • iii 4,6plil.41.Paii,. 10^i .
if•
Bil lal^• II all^i 1 14:#^, iiti nfripoll 1, iii.z .iiiikilhr
is^a
• v7.4 r iratil ^illilir nig) rail fill"fh:111.11. I" "" I^I
▪
^IN Ell11.11•IR ti* • In^%II 7 111011r IN • 114 "4^1. 1^•ISO 111
Cili "11II
illL. I^il
Figure 10. Bernard parameter versus survey line number.
C1/C2 v. Line number
600.000
500.000
400.000
••
r^•^aum ...^•el •eii-. I, . 01.1 ...to a!I ill Tr.
0.000 I^I^I^I^I^I^I^I^I^I^I^I^I^I^I0.1^CN^CNI^C.1^ND^ND^ND^.4-^LED^LLD^LID^Lr)^Lc-)
c^c^c^c^c^=^c^c^=^=^c^c^c^c^c^cL_^ L_^L_^s__c,^ 6^ ‘.._^L._^,..c3^L._
c,^c.^c+^co^c.^C:.^ CZ,^C7^ 17^1:::7^C:,^,0^ 0
C-.)^C..)^C.J^C..)^C...)^L.?^C.2^C....)^C..>^V^C_,^C-.)^C..)^C..)_
Figure 11. Methane/ethane versus survey line number.
I I^I^I^I^I^I^I^I^I
C21C3 v. Line number
4.500
4.000
3.500
3.000
2.500
L' 2.000
1.500
1.000
0.500
0.000
VU1Iii
•
• LiLo, N il •
^
Immo ill^• 1 i^1. •. Si^InT .II elIN^i ii^11110 •
1
•I 1 likrisgir.
al frikt
I^IN 11^•^-■
e . •I •^'• II^illN. !I 1
ir^in
17•• IN
P
II^ri ■•
aIII
^
,..711::^•,:.;P r.".........11,:,;-;..,B;_!:..11:...19 orl
^
I •I Tritlifl 1^llimi^
..l^mill^iii
4111_11 III: iiiI • ilmeli [•^111 ril r
^
, ..^.^.....74,.,,,,,tr ,...,.,..- rip . .....•^,..^. • ••I-ION ^!Ns I i
• a L
li I MIMI masa• %Int • m111. i 1911 ill;
• 1 P: —• LI Is%1.• 1• •^...^•r•limml • I" LO a' 11 r Vitil•" Ail if gilj ^inii % 1 . 11 uric 1101 1 0.,,,_10 _ 1._
•• %kite i i • yoll, I ILL L irl a il ..li iiii ,,1114_ dill I^1111
Ha 41
rtii.I.,1 .1 ili,t7 1,...7.,ty,..,r.i. • tr. ,. Immo., .4 rause r i=_,•I 11. 1■ L i PA. nor • il• Isom or ,
• a^,I am IP^• li •^• ••
•
•I• •
• 10-1•Ler ?PrArri-WeaVirerili
C■I^
CNI^
1.0^
1,1")^
1-C)^ kr)
t-,^
1->^
C-)^
C_7
Figure 12. Ethane/propane versus survey line number.
.-1
2cc
•
r•1
CC
LI
• ••
••o^•
•(J •••••
414WM•
44'
•••000^•
•••• • •
••••
•
1.1)
•cr
•
••
•• 1106 • NI
• • •0• a.• 0100^•
••^•^111•1111111•11111111 6 •• 0• 0^•^• • • .1^• • •
01041 • 4100 *Ma/ • 10 NM 101 • •• 00111• •0• 1111 • • • 4064 • •
•110^• • • •4^• •
•• •6• • •••• •10 4
60
50
40
30
20
10
• Fish Altitude
^ Carnarvon Basin - Fish Altitude Vs Shot Point
0^100^200^300^400^500^600^700^800
Shot Points
Figure 13. Fisrtude versus shot-point.
* ;;:0
\Q
N
0 .f:'
VI
0 VI
*
rn en tP
3.00
2.50
2.00
~ 1.50 ~
1.00
0.50
0.00 ~ '" E E E t:: .....
<::> 0 <:> 0 <..> '-' u U
% Wetness v. Line number
'" '" '" l"0 I"") I"") --r L(") L(") L(") L(") L(")
E E c: E E c:: c: E E E E c: '-- 0 ..... .....
<::> <::> <::> 0 <:> 0 0 0 0 <::> <:> u u U t.:> '-' U U U U c..> u u
Figure 14. Percent hydrocarbon wetness versus survey line number.
0.100
0.090
0.080
0.070
0.060 Q)
<= c ~ w 0.050 E c.. c..
0.040
0.030
0.020
0.010
0.000
0.00 1.00 2.00 3.00
Methane v. Ethane
•• •• • • • Ii
•• •••• • iii
• •
• •••
•
•• - •• .1.
• .-!IIiI." ••• ., •• • .. ,. . . .
• • I ••• • • 1.1 :. II. • •• ...... Ii •••
4.00 5.00
ppm Methane
• ••
•
•
• • •
•
• •• • .. ...
•
6.00
Figure 15. Methane versus ethane, all survey lines.
• •
• • •
•
• •
7.00
•
• •
•
8.00
•
•
• •
9.00
0.050
0.045
0.040
0.035
0.030 Q.) <= 10 c... 0
c:t 0.025 E c... c...
0.020
0.015
0.010
0.005
0.000
0.00 1.00 2.00
Methane v. Propane
• • • • .1 . . .
• •• •••••• ••• ••••
• •• • • • .1... •
• •
•
• •••• • ••
•
••• ••• •• • • ••• •••• ••• •••• ••• • •• •• 1 •••• 1 ••••• 1.. ••• •• • • . 1.... • .. ... . •.• .. . .. 1.... . .. 1 ... ... . 1 ...... 11.. I........ . .. .... . ... 11 ••• 11... .••. I... •. •••• 11 •• 1. •••• • •••••••• .1 ..... 1.. ... I. I.. . . .. .1........ • ..... ... . .. IIII1 .. Ja •• 1.11....... .. .1
11 •• 1 •• 1.1 ••• U •• II.. . .. ••• 11.... • •••• 1 •• 1. • • ••• • •• • 1111 •••• II... • • • . • II.. . .
• • ••
• •••• • • •
• • •
•
•
•
3.00 4.00 5.00 6.00
ppm Methane
• •
• • • •
• • • •• .1
Figure 16. Methane versus propane all survey lines.
• • • • •
• • • • •
• • • • • •
7.00 8.00 9.00
Methane v. % Wetness
3.00
• Carn-5 •
2.50 D Carn-4 • • o .. • Carn-3 •
•• ·ti· 2.00
0 Carn-2 ••• o
•• '" Carn-l • ••
on on Cl) .::
1.50 ...... Cl)
:;:: ~
••• -. 0
0 0 0
0 00
0 0 0
0 0 1.00 0 0 0
0 0 0 0 0
0.50
0.00 .. 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00
ppm Methane
Figure 17. Methane versus percent hydrocarbon wetness for all survey lines.
'" '" Q.) .:: ....... Q.)
:s: ~
3.00
2.50
2.00
1.50
1.00
0.50
0.00
0.00
• Carn-3
0 Carn-2
• Carn-l
1.00
Methane v. % Wetness
o
o
0
0
0 0 DO
0 0
0 0 0
0 0 0 0 0
2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00
ppm Methane
Figure 18. Methane versus percent hydrocarbon wetness for survey lines Carn-I, 2,3.
3.000
0.000
0.000 1.000
Methane v. % Wetness: Line Carn-2
2.000 3.000 4.000 5.000 6.000 7.000 8.000 9.000
ppm Methane
Figure 19. Methane versus percent hydrocarbon wetness for survey line Cam-2.
APPENDIX I
Individual line plots and line summary sheets,
Carnarvon survey lines 1 through 5.
------BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA ------
Line Summary
Line Number carn1 No. of Shotpoints 139
Shotpoint Date 1 29-Jul-89
Time 16:23:34 Start
End 139 29-Jul-89 20:59:29
THC Methane Ethane Mean 9.316 4.299 0.024 Std. Dev. 0.753 0.702 0.014 Minimum 7.504 3.514 0.011 Maximum 10.452 5.678 0.065
Condo Temp. F. Depth Mean 23.265 Std. Dev. 0.430 Minimum 22.540 Maximum 23.810
Notes Methane and ethane anomaly towards end of line No conductivity data were collected
10.000 0.000
10.000 10.000
Latitude 21 21
Ethylene 0.083 0.007 0.067 0.101
W.Depth 20.763
1.107 18.000 27.000
Longitude 33.061 114 26.760 115
Propane Propylene 0.016 0.034 0.003 0.003 0.010 0.022 0.026 0.043
Altitude 10.763 1.107 8.000
17.000
59.853 05.159
i-Butane 0.000 0.000 0.000 0.000
n-Butane 0.000 0.000 0.000 0.001
i-Pentane n-Pentane i-Hexane n-Hexane %Wetness 0.895 0.227 0.582 1.594
p p m
12.00
10.00
H 8.00
Y d r
6.00 o c a r b 4.00
o n s
2.00
0.00
Line CARN1 THC, Methane
• ................... -\ •• • iii ••
................................................................ Ii Ii •
\ .... ~ II: •••• ·rr •• II! .Ii ........... 111 • ••• ...... .-
-..,/ Ii .Ii ~ JIll .II! • • •• ~ ..... 1. ••• ....... ~/
•
---THe
--0-- Methane
o 20 40 60 80 100 120 140
Shotpoint
Line CARN1 Methane, Ethane, Ethylene
10.00
•••••••••••••••••••••••••••••••••••••••••••• • •• Ii ••• I! ••••••••• I! ••• ........... ~ ............................................................ ..
p P 1.00 m
H y d -II-- Methane
r 0
0.10 ---0- Ethane
c a
--+-- Ethylene
r b 0 n 0.01
s
0.00
o 20 40 60 80 100 120 140
Shotpoint
Line CARN1 Methane, Propane, Propylene
10.00
.~ •••••••••••• r .............. ~ •••••••••• w. •• ~ ...... Il - .r ......... 1l •••
•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
p P 1.00 m
H y d -.- Methane
r 0
0.10 -0-- Propane
c a r b
....................... .c.\~ ••• t~ ••••••••• / ........... ~.~'" •• ~ ... ~.~..... .~ .... -.: ........................ , f>~+ ...... \/ ........... , ••••• ,., .. ;t> •••• ., ... T. ," "-':T ••• T.~~ \! .. .~. . .'., ~
--.-- Propylene
0
n 0.01
s
0.00
o 20 40 60 80 100 120 140
Shotpoint
Line CARN1 Depths, Altitude
Shotpoint
0 20 40 60 80 100 120 140
0.0
10.0 -, ' -"',,'" ---,
20.0
30.0
40.0
M 50.0 e --- F. Depth
t 60.0 r
- - - W. Depth
e 70.0 s
- - - - - Altitude
80.0
90.0
100.0
110.0
120.0
Line Summary
Line Number carn2 No. of Shotpoints 182
Start End
Mean Std. Dev. Minimum Maximum
Mean Std. Dev. Minimum Maximum
Notes
Shotpoint Date Time 1 29-Jul-89 21 :11 :06
182 30-Jul-89 03:19:22
THC Methane Ethane 8.508 4.748 0.032 1.202 1.265 0.016 7.072 3.417 0.013
11.914 8.792 0.100
Condo Temp. F. Depth 22.442 6.637 0.470 8.483
21.890 0.000 23.560 30.000
Latitude 21 20
Ethylene 0.074 0.007 0.059 0.091
W.Depth 19.493 10.138 4.000
65.800
Longitude 26.289 115 57.253 115
Propane Propylene 0.024 0.037 0.007 0.004 0.011 0.026 0.048 0.052
Altitude 12.855 2.612 1.000
35.800
04.642 10.Q15
i-Butane 0.000 0.000 0.000 0.000
n-Butane i-Pentane n-Pentane 0.000 0.000 0.000 0.000
THe, methane, ethane and slight propane anomalies at SP 20 to 80, corresponding with South Chervil and Chervil fields Weak anomaly at SP129 near North Herald and South Pepper accumulations
i-Hexane n-Hexane %Wetness 1.200 0.364 0.490 2.425
p p m
H Y d r o c a r
12.00
10.00
8.00
6.00
b 4.00
o n s
2.00
0.00
o 20 40 60
line CARN2 THC, Methane
80 100
Shotpoint
120
---THe
--D-- Methane
140 160 180 200
10.00
P P 1.00 m
H Y d r 0
0.10
c a r b 0
n 0.01
s
0.00
o 20 40
Line CARN2 Methane, Ethane, Ethylene
60 80 100
Shotpoint
120 140
-.- Methane
-0-- Ethane
--+-- Ethylene
160 180 200
10.00
p
P 1.00 m
H Y d r
0.10 0
c a r b 0
n 0.01
s
0.00
o 20 40
Line CARN2 Methane, Propane, Propylene
60 80 100
Shotpoint
120 140 160
--.-- Methane
-0-- Propane
--+-- Propylene
180 200
o 0.0
10.0
20.0
30.0
40.0
M 50.0 e t
60.0 r e
70.0 s
80.0
90.0
100.0
110.0
120.0
Line CARN2 Depths, Altitude
Shotpoint
20 40 60 80 100 120 140 160 180 200
F. Depth
- - - W. Depth
- - - - - Altitude
Line Summary
Line Number carn3 No. of Shotpoints 140
Shotpoint Date Start End
Mean Std. Dev. Minimum Maximum
Mean Std. Dev. Minimum Maximum
Notes No hydrocarbon anomalies No conductivity data
1 30-Jul-89 140 30-Jul-89
THC Methane 6.769 3.107 0.202 0.119 5.981 2.889 7.484 3.542
Condo Temp. 23.304
0.171 22.970 23.610
No water depth of fish altitude data after SP58
Time 03:23:42 08:03:37
Ethane 0.013 0.002 0.010 0.019
F. Depth 14.000 0.000
14.000 14.000
Latitude 20 21
Ethylene 0.064 0.004 0.050 0.072
W.Depth 39.930
8.229 34.000 64.000
Longitude 57.308 115 02.625 114
Propane Propylene 0.017 0.024 0.004 0.003 0.012 0.Q18 0.027 0.037
Altitude 25.930 8.229
20.000 50.000
09.784 41.535
i-Butane 0.000 0.000 0.000 0.004
n-Butane 0.000 0.001 0.000 0.006
i-Pentane n-Pentane i-Hexane n-Hexane %Wetness 0.978 0.130 0.735 1.280
Line CARN3 THC, Methane
12.00
10.00 P P m
8.00 H Y d r
6.00 0
• • 11 .... ., iii ...... • ............... . • • I: •• ..1' ............................. .,.. ................................................... _ ......... 1' ......................... rI'\/ Ii... -. lia.
• -·-THe
---0- Methane c a r b 4.00
0
n s
2.00
0.00
o 20 40 60 80 100 120 140
Shotpoint
Line CARN3 Methane, Ethane, Ethylene
10.00
p P 1.00 m
H y d -.- Methane
r 0.10 0
c ........ "'4;.'.t; • ., ............... ~.-..; ........ '* ............................ 4fi············'t'+·~·ifi··· ... ··.·"'tft ... ·..,.·'.;···-.,;·-.;·4i· ... ·~· .. • •• *\t':t;.·':,;···'.,;········· ... ·..,:· .. • .. • .. ••• + •
-0--- Ethane
--+-- Ethylene a r b 0
n 0.01
s
0.00
o 20 40 60 80 100 120 140
Shotpoint
Line CARN3 Methane, Propane, Propylene
10.00
p P 1.00 m
H y
-.- Methane d r 0
0.10 -0- Propane
c --+-- Propylene a r b 0 n 0.01
s
0.00
o 20 40 60 80 100 120 140
Shotpoint
10.0
20.0
30.0
40.0
M 50.0 e t
60.0 r e s 70.0
80.0
90.0
100.0
110.0
120.0
o 20 40
, , ---' ..
Line CARN3 Depths, Altitude
Shotpoint
60 80 100 120 140
--- F.Depth
- - - W. Depth
- - - - - Altitude
Line Summary
Line Number carn4 No. of Shotpoints 67
Shotpoint Date Time Start End
Mean Std. Dev. Minimum Maximum
Mean Std. Dev. Minimum Maximum
Notes No hydrocarbon anomalies No conductivity data
1 30-Jul-89 08:05:36 67 30-Jul-89 10:17:39
THe Methane Ethane 6.614 3.179 0.013 0.120 0.122 0.002 6.361 2.990 0.010 6.856 3.624 0.016
Condo Temp. F. Depth 24.030 130.000 0.244 0.000
23.560 130.000 24.310 130.000
Latitude 21 21
Ethylene 0.067 0.003 0.061 0.073
W.Depth 157.955
8.925 140.000 168.000
Longitude 02.607 114 12.510 114
Propane Propylene 0.017 0.023 0.003 0.003 0.011 0.018 0.024 0.030
Altitude 27.955 8.925
10.000 38.000
41.135 38.052
i-Butane 0.000 0.000 0.000 0.003
n-Butane 0.000 0.000 0.000 0.001
i-Pentane n-Pentane i-Hexane n-Hexane %Wetness 0.925 0.095 0.728 1.190
Line CARN4 THe, Methane
12.00
10.00 P P m
H 8.00
Y d r
6.00 0
Ik - _ _ _ _ _ _._ •.• -.-.-. ... · ·-.'.'.-.-.'·'.r.-.-_-____ . __ -~",-.-_'-'._Ik _____ --'.'--- ----.'----.--'-_.'.-.'-'.r.---.--'.'---'.-.'--. - - - -·-THe
-----0- Methane c a r b 4.00
0
n s
2.00
0.00
o 10 20 30 40 50 60 70
Shotpoint
Line CARN4 Methane, Ethane, Ethylene
10.00
~._.-._._.r.-.-._._~.-.-~._~.-.-.-.-.---.-~._._._._._._._._._._._._._._._._._.-.-.-.-.-~.-.-.-.-~.-~._~._.-.-~.-~.-.-.-.-.
P P 1.00 m
H y d -.- Methane
r 0
0.10 -D--- Ethane
c a
--.-- Ethylene
r b 0
n 0.01
s
0.00
o 10 20 30 40 50 60 70
Shotpoint
Line CARN4 Methane, Propane, Propylene
10.00
~~~~.-.-~.-.-.-.-.-.-~~.-.-.-.-.-.-.-.-.-~.-.-.-.-.-.-.-.-.-.-.-~.-.-~.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-~.-.-.-.-.-.-.-~.-.-.
p P 1.00 m
H y --.-- Methane d r 0
0.10 -0--- Propane
c --+-- Propylene a r b 0
n 0.01
5
0.00
o 10 20 30 40 50 60 70
Shotpoint
Line CARN4 Depths, Altitude
Shotpoint
o 10 20 30 40 50 60 70
o +1--------~--------~--------~--------~--------4_--------4_--------~
20 I ._ . . .... 401 ........... ······························
- - - - - - - I ,- I'
. , . ,
60
M e 80 ---- F. Depth
t r - - - W. Depth
e 100 - - - - - Altitude s
120
140 r-/-----'"
\ / 160 J
180
Line Summary
Line Number carn5 No. of Shotpoints 238
Start End
Mean Std. Dev. Minimum Maximum
Mean Std. Dev. Minimum Maximum
Notes
Shotpoint Date Time 1 30-Jul-89 18:50:57
238 31-Jul-89 02 :44:47
THC Methane Ethane 6.855 3.204 0.009 0.372 0.253 0.001 6.294 2.954 0.006 7.782 3.916 0.014
Condo Temp. F. Depth 24.522 66.218 0.274 7.490
23.780 50.000 24.830 70.000
Latitude 20 20
Ethylene 0.061 0.004 0.051 0.069
W.Depth 75.752 17.317 61.000
119.000
Longitude 36.732 114 09.914 115
Propane Propylene 0.016 0.023 0.003 0.002 0.011 0.018 0.026 0.032
Altitude 18.082 9.827
10.000 49.000
I-butane anomaly SPs 39-90, in the vicinity of Central Gorgon and North Gorgon No conductivity data No water depth and altitude data between SP6 and SP 170
50.379 23.726
i-Butane 0.005 0.012 0.000 0.051
n-Butane 0.000 0.000 0.000 0.002
i-Pentane n-Pentane i-Hexane n-Hexane %Wetness 0.932 0.445 0.524 2.558
Line CARNS THC, Methane
12.00
10.00 P P m
H 8.00
Y d r 6.00
---THe
0 -0--- Methane
c a r b 4.00
0
n 5
2.00
0.00
o 50 100 150 200 250
Shotpoint
Line CARNS Methane, Ethane, Ethylene
P P 1.00 m
H y d -.- Methane
r 0
0.10 -0-- Ethane
c a
--.-- Ethylene
r b 0
n 0.01
s
0.00
o 50 100 150 200 250 Shotpoint
Line CARNS Methane, Propane, Propylene
p P 1.00 m
H y d --.-- Methane
r 0
0.10 -0-- Propane
c a
--+-- Propylene
r b 0
n 0.01
s
0.00
o 50 100 150 200 250
Shotpoint
0 50
0.0
10.0
20.0
30.0
40.0
M 50.0 e t
60.0 r e
70.0 s
80.0
90.0
100.0
110.0
120.0
Line CARNS Depths, Altitude
Shotpoint
100 150
, ,
"
, I , .. 1\
.J..J"', ,
200
~v~ ('V
/ I J
I
250
--- F. Depth
- - - W. Depth
- - - - - Altitude
APPENDIX II
DHD METHODOLOGY
Direct hydrocarbon detection in bottom-water (DHD) is accomplished with the
equipment schematically shown in Figure II-I. The equipment comprises four major
components.
(1) The over-the-side gear includes a towed 'fish' fitted with a submersible pump which
delivers seawater to the geochemical laboratory on the ship via a hollow cable. A
conductivity/temperature/depth sensor (CTD) in the 'fish' measures the depth of the
'fish' as well as the temperature and salinity of the seawater (to relate the depth of
sampling to the depth of the thermocline, to detect hydrographic 'fronts', and to detect
sub-seafloor freshwater aquifers that may drain through sedimentary layers from the
continent). A sonar measures and continuously displays the altitude of the 'fish' above
the seafloor allowing the operator to maintain the 'fish' at an altitude of about 10 m.
(2) A hollow cable (consisting of medical grade nylon tubing wrapped with insulated
conductors which both transmit power to the fish and relay CTD and sonar data from
the 'fish') delivers bottom-water to the geochemical laboratory. The tubing and
conductors are wrapped in a stainless steel braid. Plastic fairings, which are attached to
the cable to reduce frictional drag, allow the 'fish' to be towed almost directly beneath
the ship.
(3) The analytical equipment includes a gas extraction unit and gas chromatographs
connected in parallel to measure the concentrations of a variety of (C l-CS)
hydrocarbons extracted from the seawater. The total hydrocarbon concentrations are
measured every 30 seconds or at a ship speed of 5 knots, a distance of about 75 m on
------BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA ------
the seafloor. The light hydrocarbons (C l-C4) are measured at 2 minute intervals
(approximately 300 m on the seafloor), whereas the CS-Cg hydrocarbons are measured
every g minutes (approximately 1200 m). Sub-samples of extracted gas may be taken
and stored for subsequent shore-based isotopic analyses.
(4) The data acquisition system is PC based: all data is displayed, edited and stored in a
database for plotting at sea.
The towed 'fish' is deployed over the stern from the M.V. Mermaid Searcher. Echo
sounder data and GPS navigation are displayed in the laboratory and these provide
clues to the locations of surface expressions of gas seeps on the seafloor. All data are
recorded continuously so that any hydrocarbon anomalies in the water column can be
quickly recognised and additional measurements (or samples can be collected) if
appropriate.
Detector sensitivity is < 10 parts per billion in the stripped heads pace sample.
Calibrations were conducted on a daily basis and were within 10% for the entire
program and system blanks were less than 2 ppm for methane and 5 ppb for C2+
compounds.
------BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA ------
The following parameters are measured:
Parameter Units
Total Hydrocarbon (THC) ppm
Methane
Ethane
Ethylene
Propane
Propylene
i-Butane
n-Butane
i-Pentane
n-Pentane
i-Hexane
n-Hexane
Water Depth
Fish Altitude
Conductivity
Water Temperature
Fish Depth
ppm
ppm
ppm
ppm
ppm
ppm
ppm
ppm
ppm
ppm
ppm
Metres
metres
mmhos/cm
°Celsius
d-bar
Equipment Used
Shimadzu GC with Fill
Detector using 6" Glass
bead column
Shimadzu GC with FID
Detector using 42"
Activated alumina column
" " " "
"
" Shimadzu GC with FID
Detector using 30
Megabore DB! column
" Shimadzu GC with FID
Detector using 30
Megabore DB! column
"
On-board Echo sounders
Water Depth minus Fish
Depth
Conductivity Meter
Temperature thermistor
Pressure transducer
------BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA ------
Seawater
i Dissolved Co gases .~ ... (J)
Drain
Concentration
L Position
Shurebased
High resolution seismic, side scan sonar, 3 and 12 KHz
23/J55/48
Figure II -1. Schematic of the geochemical equipment aboard Rig Seismic for the
continuous profiling of hydrocarbons in seawater: the bottom-water DHD technique.
-------BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA -------
APPENDIX III
INTERPRETATIVE METHODOLOGY
The DHD equipment installed on Rig Seismic can be used for measuring hydrographic,
environmental or petroliferous parameters. The light hydrocarbon data (C 1 to C6)
contained in this report can be produced by a variety of sources. These sources
include biological activity associated with the degradation of organic matter in
seawater and near-surface sediments and reservoired petroleum products (oil, gas and
condensate). The aim of the data interpretation is to determine the origin (biogenic or
thermogenic) of the light hydrocarbon gases measured, and via a variety of cross-plots
of molecular and isotopic compositions of gases, to infer the 'source' (dry gas, gas
condensate or liquids) of detected seepage.
Light Hydrocarbons In Seawater
Light (C1-C4) and intermediate (C5-C8) hydrocarbons are present in seawater and
sediments principally as a result of the following three processes.
(l)Thermogenic processes. The effect of heat on organic matter (catagenesis and
metagenesis) buried to depths of several kilometres in sedimentary basins produces
thermogenic hydrocarbons (Hunt 1979; Tissot and Welte 1984). The products of
these reactions include methane and the saturated (C2-C8) hydrocarbons, which are
the hydrocarbons mostly analysed in surface geochemical techniques. Some of the
thermogenic hydrocarbons migrate to the surface, either directly from source rocks
(primary migration) or indirectly, from gas, gas-condensate or liquid reservoirs
(secondary migration). Hydrocarbons may migrate kilometres to permeate the near-
------BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA ------
surface sediments and seep into the overlying bottom-water resulting in thermogenic
anomalies.
(2)Biological processes. Hydrocarbons are produced microbially and photochemically
in seawater. In addition, during early diagenesis, a variety of hydrocarbons are
produced by the activities of microbial organisms during aerobic and anaerobic
destruction of organic matter which occurs primarily in the top few tens of metres of
sediments. The products of these reactions include methane and minor quantities of
both saturated and unsaturated hydrocarbons (Hunt 1979; Claypool & Kvenvolden
1983 and references cited therein). The presence of the unsaturated hydrocarbons,
which are only produced biochemically (Primrose & Dilworth 1976; Claypool &
Kvenvolden 1983), provides one criteria to distinguish between biogenic and
thermogenic hydrocarbons.
These compounds produced in-situ generally occur in low concentrations as
background hydrocarbons in seawater (Claypool & Kvenvolden 1983). However, high
concentrations of biogenically-produced hydrocarbons may accumulate in relatively
shallow-buried sediments and seep into the overlying water, resulting in biogenic
anomalies (Brooks et al. 1974; Bernard et at. 1976).
(3)Anthropogenic processes. Man's activities can introduce anthropogenically-sourced
hydrocarbons into the marine environment. Anthropogenic hydrocarbons may be of a
thermogenic origin (e.g., ship spills, refined petroleum products used in industrial
processes) or a biogenic origin (such as those produced from urban sewage when
excessive loads of organic matter are dumped into the sea and degraded microbially).
The concentrations of in situ biogenic (i.e., background) light hydrocarbons in
seawater are generally an order of magnitude lower than those in the underlying
seafloor sediments (Claypool & Kvenvolden 1983). Consequently, it is relatively
------BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA ------
easier to detect migrated thermogenic hydrocarbons in seawater (low background
concentration) than in seafloor sediments (high and variable background
concentrations). Herein, lies one perceived advantage in the use of bottom-water DHD
compared with sediment geochemistry in offshore petroleum exploration.
The bottom-water DHD technique is dependent upon hydrocarbons migrating from
hydrocarbon reservoirs or petroleum source rocks to the seafloor. Although the exact
mechanism(s) of migration may be variable or even unknown, some form of vertical
migration, as evidenced by the many observations of seepage (e.g., Brooks et aI. 1974;
Bernard et aI. 1976; Reed & Kaplan 1977; Cline & Holmes 1977; Nelson et aI. 1978;
Reitsma et aI. 1978; Brooks et aI. 1979; Kvenvolden et aI. 1979; Kvenvolden & Field
1981; Hovland & Judd 1988) does occur (via porous sediments, fault planes and
microfissures etc). It is generally accepted that migration by diffusion is not important
(Leythaeuser etal., 1982; Reitsma et aI. 1981; Whelan et aI. 1984) although bubble
ebullition from saturated solution, oil and gas transport in solution in carbon dioxide
and advective processes involving basinal fluids are all likely mechanisms (e.g.,
Kvenvolden & Claypool 1980; Hunt 1984; Sweeney 1988; Hovland & Judd 1988).
Data interpretation: the mixing model
The detection of seepage requires that anomalous concentrations of hydrocarbons be
distinguished from the background inventory of hydrocarbons. Thermogenic
hydrocarbons that seep into the bottom-waters mix with the background concentration
of hydrocarbons. One approach to defining anomalies and distinguishing seep
hydrocarbons from background hydrocarbons requires that a mean background
concentration be defmed (either statistically or graphically), and this mean
concentration is then subtracted from the measured concentrations. Because of
variability in the background concentrations, this approach may be problematic,
particularly where seepage is weak and the anomalies are very subtle.
------BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA ------
Our initial approach is to review the data on a line-by-line basis and compare measured
concentrations with the regional background. Then, a variety of hydrocarbon cross
plots are constructed, particularly where methane is plotted versus percent
hydrocarbon wetness (wetness % = [SUM(C2-C4)/SUM(Cl-C4)] xlOO) to delineate
seepage. The rationale behind this plot (Figure III -1) is that different hydrocarbon
'sources' e.g., biogenic versus thermogenic gas, condensate and liquids, can be
distinguished on the basis of differences in their light hydrocarbon molecular
compositions (Hunt 1979; Tissot & Welte 1984; Claypool & Kvenvolden 1983). In
this model background hydrocarbons plot in a narrow range towards the left origin
(low concentrations), while end-member 'source' hydrocarbons i.e., hydrocarbons from
either oil-prone, condensate-prone or gas-prone source rocks or reservoirs, plot to the
right (high concentrations).
As the hydrocarbons in bottom-waters represent mixtures of the end-member
background (low) and 'source' (high) concentrations, the trends between the end
members in these plots are indicative of the 'source' of the hydrocarbons comprising the
anomalies. For example, when the % hydrocarbon wetness increases with increasing
methane concentration, the trend indicates that the anomaly was probably derived from
a gas-condensate or oil-prone 'source'. In contrast, increasing methane concentrations,
coupled with decreasing % hydrocarbon wetness, suggest that the anomaly was
derived from a gas-prone thermogenic 'source' or is of a biogenic origin. This model
cannot distinguish between biogenic and gas-prone thermogenic anomalies. Carbon
isotope (e.g., Fuex 1977; Bernard et al. 1977) and molecular compositional data are
required to discriminate between biogenic gas and 'dry' thermogenic anomalies.
------BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA ------
Classification of anomalies.
'Strong' (arbitrarily defmed here as when some of the measured CI-C4 concentrations
increase more than an order of magnitude above the background concentration) and
'moderate' thermogenic anomalies (some CI-C4 increase 5-10 fold above background)
are obvious and are accompanied by large increases in individual C I-C4 hydrocarbons
with no increase in the biogenic components (ethylene and propylene). Weak'
anomalies (individual CI-C4 is less than five-fold the background concentration) are
more difficult to discern. In some cases, what appear to be weak anomalies may result
from variations in the depth of the fish above the seafloor, a shoaling of the water
depth, penetration of the fish above the local thermocline or combinations of these
factors. In these cases, plotting the saturated hydrocarbon (methane, ethane, propane)
concentrations against the 'fish' depth, seawater temperature and salinity, or against the
biogenic hydrocarbons (ethylene, propylene), generally resolves apparent anomalies
from those anomalies related to seepage.
A cross plot of two compounds (e.g., ethane vs. methane) indicates whether the
compounds are being added to the natural hydrocarbons in an area. Positive trends on
plots of one compound versus another indicate that both compounds are being added
concurrently and thus, the source of the anomaly contains both compounds. Because a
mixing trend is created by one hydrocarbon source supplying hydrocarbons to the
background, all data on the same trend reflect the same source regardless of the
absolute concentrations or absolute ratios. For example, an anomaly with ethane at 0.1
ppm would reflect the same hydrocarbon source as a second anomaly with ethane
values at 1.0 ppm if the data from the two anomalies lie on the same mixing trend.
Similarly, an anomaly with a wetness of 2% (oil-like) may actually represent a dry gas
source if it falls on a mixing trend that has low wetness values at higher concentrations.
------BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA ------
+
'" () I LOW --+-
OIL-SOURCED HYDROCARBONS
WET GAS AND CONDENSATE
DRY' IHERMOGENI OR BIOGENIC GAS
HIGH
Methane concentration 12/0A/17
Figure III-I. Cross-plot of methane versus hydrocarbon wetness, showing the general
decrease in wetness with increasing methane for gas-prone or biogenic sources.
Conversely, oil-prone sources are indicated by increasing wetness with increasing
wetness with increasing methane. Gas-condensate sources fall between the dry gas and
oil-prone trends.
------~BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA -------
APPENDIX III REFERENCES
Bernard, B.B., Brooks, J.M. & Sackett, W.M. (1976), Natural gas seepage in the Gulf
of Mexico, Earth and Planetary Science Letters 31, 48-54.
Bernard, B.B., Brooks, J.M. & Sackett, W.M. (1977), A geochemical model for
characterization of hydrocarbon gas sources in marine sediments. In: 9 th Offshore
Technology Conference, Houston, Texas, OTC 2934, 435-438.
Brooks, J.M. Gormly, J.R. & Sackett, W.M. (1974), Molecular and isotopic
composition of two seep gases from the Gulf of Mexico. Geophysical Research Letters
1,213-216.
Brooks, J.M., Bernard, B.B. Sackett, W.M. & Schwarz, J.R. (1979), Natural gas
seepage on the south Texas shelf. In: 11th Offshore Technology Conference Houston
Texas, OTC 3411, 471-474.
Claypool G.E. & Kvenvolden, K. A. (1983), Methane and other hydrocarbon gases in
marine sediment. Annual Review of Earth and Planetary Science 11,299-327.
Cline, J.D. & Holmes, M.L. (1977), Submarine seepage of natural gas in Norton
Sound, Alaska. Science 198, 1149-1153.
Fuex, A.N. (1977), The use of stable carbon isotopes in hydrocarbon exploration.
Journal of Geochemical Exploration 7,155-188.
Hovland, M. & Judd, A.G. (1988), Seabed Pockmarks and Seepages Impact on
Geology, Biology and the Marine Environment. Graham and Trotman, Ltd. London.,
293pp.
------BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA ------
Hunt, J.M. (1979), Petroleum Geochemistry and Geology, Freeman & Co, San
Francisco., 617pp.
Hunt, J.M. (1984), Generation and migration of light hydrocarbons Science 226,
1256-1270.
Kvenvolden K.A., Vogel, T.M. & Gardner, J.V. (1979), Geochemical prospecting for
hydrocarbons in the outer continental shelf, southern Bering Sea. Journal of
Geochemical Exploration 14,209-219.
Kvenvolden K.A. & Claypool, G. E. (1980), Origin of gasoline-range hydrocarbons
and their migration by solution in carbon dioxide in Norton Sound, Alaska. American
Association of Petroleum Geologists Bulletin, 64, 1078-1086.
Kvenvolden, K.A. & Field, M.A. (1981), Thermogenic hydrocarbons in
unconsolidated sediment of Eel River Basin, offshore northern California. American
Association of Petroleum Geologists Bulletin, 65, 1642-1646.
Leythaeuser, D., Schaefer, R.G. & Yukler, A. (1982), Role of diffusion in primary
migration of hydrocarbons. American Association of Petroleum Geologists Bulletin
66,408-429.
Nelson, H. Kvenvolden, K.A. & Clukey, C. (1978), Thermogenic gases in near-surface
sediments of Norton Sound, Alaska. 10th Offshore Technology Conference, Houston,
Texas, OTC 3354, 2623-2333.
Primrose, S.B., & Dilworth, M. J. (1976), Ethylene production by bacteria. Journal of
General Microbiology 93,177-181.
------BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA ------
Reed, W.E. & Kaplan, I.R (1977), The chemistry of marine petroleum seeps. Journal
of Geochemical Exploration 7, 255-293.
Reitsma, RH., Lindberg, F.A. & Kaltenback, AJ. (1978), Light hydrocarbons in Gulf
of Mexico water: sources and relation to structural highs. Journal of Geochemical
Expwration 10, 139-151.
Reitsma, RH., Kaltenback, A.J. & Lindberg, F.A. (1981), Source and migration of
light hydrocarbons indicated by carbon isotopic ratios. American Association of
Petroleum Geologists Bulletin 65, 1536-1542.
Sweeney, R E. (1988), Petroleum-related hydrocarbon seepage in a recent North Sea
sediment. Chemical Geology 71,53-64.
Tissot, B.P. & Welte, D.H. (1984), Petroleum Formation and Occurrence. Springer
Verlag, New York., 697pp.
Whelan, 1K., Hunt, 1M., Jasper, J. & Huc, A. (1984), Migration of CI-C8
hydrocarbons in marine sediments. Organic Geochemistry 6,683-694.
------BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA ------
APPENDIX IV
SYSTEM OPERATIONS REPORT
Relatively few problems were encountered with the geochemical laboratory acquisition
system during the survey. Water depth data was determined with a portable over-the
side echo sounder. The intermittently faulty digital altimeter meant that ftsh altitude
was calculated from water depth and ftsh depth for much of the survey. Problems with
the tow cable and winch on survey line Carn 4 and Carn 5 resulted in the tow ftsh not
being able to be towed close to the seafloor.
DHD
Conductivity data is not included in the line summary sheets for this report, however,
salinity data is included in the ASCII files in Enclosure 1.
NON GEOCHEMICAL SYSTEMS
Navigation was provided by a combination of Global Positioning Satellite (GPS) and
transit satellite navigation by Racal Survey Ltd (Perth W A). Accuracy of recorded
positions are +/- 20 metres when GPS was operational and +/- 100 metres when transit
satellite was on-line.
------BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA ------
Enclosure 1
Floppy disk with ASCII fIle of geochemical data.
------BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA ------
Enclosure 2
Map showing DHD survey lines
------BUREAU OF MINERAL RESOURCES, GEOLOGY AND GEOPHYSICS, AUSTRALIA ------
CRRNRRVON BRSIN 225~H?J0M E
20 00 00S
20 3121 I2II21S
+
21 00 01215
+
21 30 I2II21S
~o ...
o I (0
6'
~/
/ -CHINOOK
tRIFFIN 1-3 (,j
(?
~~
<i'
... It.
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22 00 ~101 00 1210E 114 3121 00E
I;HII:'II:'II:'II:'II:'I ~ ~ ~ W M ~ L.. ---J I I I I
KILOMETRES
" 11:'1 21!! 31!! 41!! 51!! I I
MILES UNIVERSAL TRANSVERSE MERCATOR PROJECTION
AUSTRALIAN NATIONAL SPHEROIO CENTRAL MERIDIAN 117 ee BBE
o
312112101210M E
rF
'TRYAL ROCKS 1
+
+
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115 00 00E
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115 30 00E
375121121I21M E
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0
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+
772500121M N
0
765121121121I21M N
7575000M N
116 0121 I2II21E
l OHD SURVEY LINES I TEG/BMR CALIBRATION SURVEY
/ ..-(
RRRFURf~ SER 200000H E 400000H E 600000H E
8 30 005
I + + + 9000000M N
I
" 10 00 005 !W!II9
8800000H N
I
134 00 00E 136 00 00E 137 30 00E
_____ ~DH~D=_ ~SLURVEY LINES
RRRFURR BRS I N SURVEY
S16RRRFU.PIC -=~~~==~~tilE~~====~B~~=-- l~~
UNIVERSAL MILES .d TR'FI45VEIt3: !'£RCR
RUSTRR...JAN ~TJ()..IRL rm PRDJECTICH
C£NTRIL tt:KIOIFH SPIfl!OlD 1~5 111 IIIE
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20 30 00S
21 00 005
21 30 005
22 00 00S 114 em 00E
2~ !
225000M E
+
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CARNRRVON BRSIN 300000M E
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·TRY;AL ROCKS 1
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114 30 00E 115 00 00E 115 30 00E
1: HI~~~~~ 40 60
I I 80
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375000M E
7725000M N
r /g) 0
0
0°
7650000M N
+ 7575000M N
116 00 00E
KILOMETRES TEG/BMR CALIBRATION SURVEY
~ H~ 211J 311J 411J 511J !~~=-~!======b!=====d!======±!=====:d=d
MILES UNIVERSAL TRANSVERSE MERCATOR PROJECTION
RUSTRALIRN NATIONRL SPHEROID CENTRA.. nERIDIFt.! 117 I!l0 lIE
L-______________________________________________________ ~. __ .-.~~ __ ~ ________ __
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