1) The document summarizes the 2009 Gorgon CO2 3D Seismic Baseline Survey conducted off the coast of Barrow Island, Western Australia. 2) The survey was conducted to acquire seismic data to monitor the movement of injected CO2 as part of Chevron's Gorgon Project, which will be the world's largest CO2 injection project to reduce greenhouse gas emissions. 3) Innovative technical designs and operations were employed to minimize environmental impacts and successfully complete the survey within strict environmental, regulatory, and safety restrictions for Barrow Island, including using different seismic energy sources, custom seismic equipment, and manual deployment to reduce land disturbance to just 0.14% of the project area.

1. SPE 132931
Setting New Environmental, Regulatory and Safety Boundaries: The 2009
Gorgon CO2 3D Seismic Baseline Survey, Barrow Island, Western Australia
Kevin C. Scott, SPE, Chevron Australia Pty Ltd; Donna J.Parker, SPE, ExxonMobil Australia; Aimee Cairns, Chevron
Australia Pty Ltd; and Bruce Clulow, WesternGeco
Copyright 2010, Society of Petroleum Engineers
This paper was prepared for presentation at the SPE Asia Pacific Oil & Gas Conference and Exhibition held in Brisbane, Queensland, Australia, 18–20 October 2010.
This paper was selected for presentation by an SPE program committee following review of information contained in an abstract submitted by the author(s). Contents of the paper have not been reviewed
by the Society of Petroleum Engineers and are subject to correction by the author(s). The material does not necessarily reflect any position of the Society of Petroleum Engineers, its officers, or mem-
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Abstract
The Approved Gorgon Gas Development (Gorgon
Project) is developing the Gorgon and Jansz-Io Gas Fields,
and includes the construction of a Liquified Natural Gas
(LNG) plant on Barrow Island. The project is expected to
commence extraction and processing LNG in 2014.
The Gorgon Project is operated by Chevron. It is a
joint venture of the Australian subsidiaries of Chevron (ap-
proximately 47 percent), ExxonMobil (25 percent) and Shell
(25 percent), Osaka Gas (1.25 percent), Tokyo Gas (one
percent) and Chubu Electric (0.417 percent).
The Gorgon Project’s CO2 Injection Project will
safely inject up to 3.8 MTPA of CO2 from LNG processing
activities. The CO2 Seismic Baseline Survey (the Survey)
was undertaken as part of Chevron Australia’s commitment
to develop and implement a monitoring program to track the
performance of the CO2 injection system. The aim was to
acquire good quality seismic data over the area where the
injected CO2 is expected to migrate to enable monitoring of
the injected CO2 in the subsurface over time.
Barrow Island is a Class A Nature Reserve and all
operational activities are subject to strict environmental and
quarantine controls to protect its conservation values. Che-
vron Australia and its primary seismic contractor Western-
Geco, aligned environmental, health and safety management
principles during the Survey’s planning and execution phas-
es to enable best practice project outcomes to be achieved
within the operational restrictions.
The final design of the Survey was a successful
balance of technical objectives with land usage and envi-
ronmental restrictions, and covered 135 km2
of the northern
half of Barrow Island. Three source types were used to en-
sure the best quality seismic data was obtained and the pro-
jected CO2 plume area was completely covered. The Sur-
vey’s design also considered future risks associated with
heliportable drilling operations and the use of explosives
near future Gorgon Project infrastructure when planning for
future seismic surveys to monitor the CO2 in the subsurface.
Environmental, Regulatory and Safety Achievements
• Achieved an environmental footprint of only 19 hec-
tares over the 135 km2
project area (0.14% total land
use). A similar-sized vehicle deployed survey would
normally result in the disturbance of 250 to 300 hectares
of land.
• Design and deployment of state of the art modularized
heliportable shot hole rigs equipped for both sonic and
air percussion drilling to minimise the use of drilling
fluids.
• WesternGeco, working closely with Chevron Quaran-
tine Inspectors, mobilized a significant amount of seis-
mic equipment from multiple overseas locations using
procedures and specifications of the Gorgon Project’s
Quarantine Management System that resulted in no
post-border quarantine incidents on the Class A Nature
Reserve.
• Executed the Survey under the complex Barrow Island
Act 2003 (WA) regulatory framework which required
granting of land tenure for areas to be disturbed versus a
typical petroleum access authority. Worked with the
regulatory agencies to allow for real-time movement of
vibroseis lines and seismic shot points to avoid unique
flora and fauna habitats identified during the course of
the Survey to achieve best environmental outcome.
• Successfully bridged the Western Geco (Schlumberger)
and Chevron Safety Management Systems that sup-
ported execution of over 170,000 manhours of manual
and high risk operations including heliportable drilling,

2. 2 SPE 132931
shallow transition zone marine, and manual handling
over rugged Barrow Island terrain without a significant
environmental, regulatory, or safety incident.
The Gorgon Project
The Chevron Australia-operated Gorgon Project is
one of the world’s largest natural gas projects and the larg-
est, single resource project ever undertaken in Australia’s
history. The Gorgon Project will develop the Gorgon and
Jansz-Io area gas fields, located about 130 kilometres off the
north-west coast of Western Australia. It includes the con-
struction of a 15 million tonne per annum (MTPA) Liquefied
Natural Gas (LNG) plant on Barrow Island and a domestic
gas plant with the capacity to provide 300 terajoules per day
to supply gas to Western Australia. Gorgon LNG will be off
loaded via a four kilometre long loading jetty for transport to
international markets. The domestic gas will be piped to the
Western Australian mainland (Figure 1).
The Gorgon Project’s gas processing facilities must
be constructed within a 300 hectare ground disturbance lim-
it, which represents approximately 1.3% of Barrow Island’s
uncleared land area. The project is currently in the construc-
tion phase and is scheduled for first gas in late 2014. Bar-
row Island is located about 50 km off the northwest coast of
Western Australia.
World’s Largest CO2 Injection Project
Gas from the Gorgon Field gas contains 14-16% of
naturally occurring CO2 which will be routinely removed
during gas processing operations. As an alternative to dis-
posal via atmospheric venting, the Gorgon Joint Venture is
investing approximately $2 AUD billion in the design and
construction of the world’s largest commercial-scale CO2
injection facility to reduce the Project’s overall greenhouse
gas emissions by approximately 40% or 3.8 million tonnes
per year.
Reservoir CO2 will be extracted and compressed
during gas processing and injected into the Dupuy Forma-
tion about 2200m below Barrow Island. When injected, the
CO2 will become trapped in the sandstone and gradually
dissolve into the saline aquifer where it will remain perma-
nently stored in the host reservoir (Figure 2).
After injection has commenced, a reservoir surveil-
lance program will monitor movement of the injected CO2
and observe the effects of injection on the formation. The
movement of the injected CO2 will be monitored using time-
lapse seismic data and surveillance wells to detect the arrival
time and quantify the volume of CO2 at the well.
Approximately 120 million tonnes of CO2 will be
safely injected underground during the life of the Gorgon
Project, almost six times more than any other project in the
world. This will position Australia as a world-leader in CO2
injection technology, which could be adopted around the
world and assist in offsetting the environmental impact of
other energy projects.
The Environmental Values of Barrow Island
The island is very arid and the topography consists
of limestone cliffs, and undulating terrain witih surface ex-
pressions of karst limestone, and mostly, low lying vegeta-
tion such as Spinifex. Barrow Island is just 25 kilometers in
length and has a total landmass of nearly 235 square kilome-
ters. It is inhabited by many unique species of flora and
fauna which provides a snapshot of the biodiversity that was
present on the Australian mainland 8,000 – 10,000 years
ago.
Further, the island is home to a number of plant and
animal species which have become rare or extinct on the
Australian mainland, particularly mammals, including the
endangered bettong (boodie), the spectacled hare-wallaby,
and the golden bandicoot, all which have become rare or
extinct on the mainland.
As a result of its unique ecosystem, Barrow Island
was declared an A Class Nature Reserve by the Common-
wealth government in 1910, and strict environmental and
quarantine requirements are in place to protect the Island’s
unique environmental values. A strict environmental man-
agement plan provided by Chevron Australia for Barrow
Island Joint Venture oil operations on Barrow Island pro-
tected the island’s unique flora and fauna and has enabled
petroleum activities to successfully coexist with the island’s
nature reserves for the last 46 years.
The marine environment surrounding the Island is
also an important protected area for the marine life, and is a
nesting and breeding area for flatback turtlesdugongs,
whales, and dolphins. The coral reef, macro-algae, and sea
grass provide a perfect hiding and breeding place for the
various species of fish found in the reefs around Barrow
Island.
Innovative Technical Design
The Baseline Survey scope of work had to be de-
veloped within the following parameters:
• The physical characteristics of Barrow Island
• A total land use restriction of 25 hectares
• Compliance with regulation and legislation
• Gorgon Project approvals
• Corporate policies and standards
• Interface with existing oilfield operations and Gorgon
Project construction activities
In order to meet the geophysical, technical and en-
vironmental objectives, an innovative geophysical design
was required for the Survey. The shallow geology of Bar-
row Island makes seismic acquisition difficult; hence three
different seismic energy source types were used:
• In areas of higher elevations, shallow porous limestone
layers and varied terrain, explosives were placed into
shot holes drilled to below sea level.

3. SPE 132931 3
• In areas of lower elevation, a vibroseis (seismic vibra-
tor) source was used to better attenuate background field
noise.
• In the shallow waters adjacent to Barrow Island, a low-
energy airgun source array was used that maximised
seismic signal but minimised impacts on marine fauna.
The geophone arrays for recording the seismic data
were custom-built to ensure that the quality of recorded
seismic data would be optimized. Large, crossed receiver
arrays were used, despite being more difficult to manually
deploy without vehicle access, while special “clam shell”
shaped geophones were used in intertidal areas.
A key design feature is that future repeat seismic
surveys to monitor the injected CO2 will not require heli-
portable drilling operations or use of explosives near exist-
ing Gorgon infrastructure (Figure 3 is a map of the northern
two-thirds of Barrow Island and shows the extent of the
2009 3D Seismic Survey).
The use of a combination of source types and large
receiver arrays successfully reduced the effects of scattered
noise and was an appropriate design to overcome restrictions
and achieve the Survey’s objectives.
Initial tests indicate that the final dataset is signifi-
cantly better than any previous seismic data acquired on
Barrow Island and is able to be effectively used in injection
planning and as a baseline for monitoring the injected CO2.
Development of New Seismic Drilling Technology
The geology of Barrow Island has traditionally
made drilling very difficult. The construction of mud pits
and the use of chemicals is the standard method for drilling
the Barrow Island geology, but was not the preferred method
for the Survey given the land use constraints. Figures 10
and 11 are pictures showing the detail of the seismic shot
hole drilling rigs.
In order to overcome these challenging shallow
drilling and environment risks, the following innovations
were implemented:
• Hydraulic legs were constructed under the drilling rigs
and stilts under the supporting equipment to raise them
above vegetation and minimize disturbance.
• Purpose-built air percussion/sonic drilling rigs were
designed to penetrate inter-bedded layers of fine sands
and rock that minimized the use of fluids to assist the
drilling process.
• Cuttings were managed during the drilling process by
collecting and re-using most of the waste rock and soil
as stemming in the shot holes.
Minimizing Ground Disturbance
Seismic surveys generally utilise graders or vegeta-
tion-slashers to clear long access tracks across the survey
area. These tracks provide clear access to vibroseis trucks,
trailer-mounted drilling rigs and vehicle deploying equip-
ment. The geophone array lines are usually also graded in
areas of rough terrain to enable better coupling with the
ground and are deployed by vehicles to increase the speed of
operations and minimise manual handling risks to personnel.
These methods on a similar-sized survey would normally
result in the disturbance of 250 to 300 hectares (ha) of land.
Despite the survey needing to acquire seismic data over a
total of 13,500 hectares on Barrow Island and the near-shore
marine areas, the Chevron baseline seismic survey was allo-
cated just a 25 hectare ground disturbance limit.
The Survey’s innovative design strategies ensured
that actual ground disturbance was less than 19ha in total.
This is just 0.1% of the total area over which the Survey was
undertaken. No permanent infrastructure was established
during operations, meaning disturbance was temporary and
intermittent (planned to be repeated every 8-10 years).
As a result of the ground disturbance limitations,
operational activities and equipment were modified to re-
duce the project’s ‘footprint’ within the geophysical parame-
ters of the Survey. Innovations implemented to reduce
ground disturbance included:
• Vibroseis trucks were modified to reduce the tire and
axle widths from 3.2 meters to 2.6 meters to minimize
track width. See Figure 8 for a ground aspect of two vi-
broseis vehicles and Figure 9 for an aerial picture of a
vibe truck minimal impact footprint on the vegetation in
the Survey.
• A specialized lifting helicopter, Kaman K-Max,was
used to transport seismic equipment and seismic drilling
rigs which would normally be mounted on or deployed
by vehicles. Figure 7, 12 and,13 show various pictures
of the helicopter at work on Barrow Island.
• The shot points and vibroseis lines were placed onto
existing cleared areas whereever practicable.
• Approximately 200,000 kilograms of seismic equipment
(13,284 receiver points) was manually deployed and
picked-up by hand by the field crew, a significant
achievement considering the terrain and hot weather
conditions.
• An estimated 43,000 kilometers was walked by the crew
between shot holes and to deploy seismic equipment
(equivalent to walking from Perth to Sydney seven
times).
Marine Seismic Activities
Prior to commencing shallow-marine operations,
Chevron conducted a high resolution bathymetric survey
around the northern and eastern coasts of Barrow Island,
using airborne LiDAR technology. This resulted in a 3x3
meter elevation grid over the ocean floor. This information

4. 4 SPE 132931
was downloaded into the vessel’s navigation system as a
contour map and shown as a background to the vessel’s
course. This visual aid proved invaluable in planning a
course through the many hazardous shallow water shoals
and reefs.
A small vessel was contracted for the shallow-
marine seismic component of the Baseline Survey. The
‘Aimee’ was an aluminum hulled, twin-engine, jet boat with
a 0.7 meter draft that made it ideal for shallow water and
tidal zone seismic operations. It was 17.7 meters long and
3.7 meters wide which allowed it to carry the necessary load
of generator, compressors, air storage tanks, gun array and
davits (Figure 14).
An airgun array was selected that would perform
well into the shallowest of waters safely navigable by an
optimum tow vessel for the shallow waters along the east
coast of Barrow Island. This array was Prakla’s D008 shal-
low water array comprising 20 VLF airguns totalling 505in3
(8.3litres) in capacity, with an operating pressure of 2000psi.
These airguns are relatively small for airgun arrays (~10 –
30in3
/ 0.16 – 0.6litre) and when arranged in the supplied 5
cluster configuration provides optimum peak – peak energy
and peak bubble ratios in shallow water (minimum water
depths entered were 2.5 – 3m).
The D008 array and towing configurations pro-
vided by WesternGeco proved ideal for the technical re-
quirements and water depth constraints.
To ensure the safe sea to land transfer of the marine
seismic crew assigned to the ‘Aimee’, a shallow draft jet
launch was provided to shuttle personnel from the seismic
vessel anchorage of Barrow Island to a jetty near the old
WAPET landing (Figure 15).
Marine Fauna Observation (MFO)
The guidelines on the application of the Environ-
mental Protection and Biodiversity Conservation Act 1999
(Cth) for interactions between offshore seismic operations
and larger cretaceans were adhered to during the marine
component of the Survey’s operations to ensure impacts to
marine fauna were minimized. The following design and
operational impact mitigation strategies were implemented:
• Visual observations during pre-start procedures and dur-
ing the Survey;
• Soft start procedure (prior to the firing of the airguns);
• A shallow water source array was selected that maxi-
mises seismic signal per unit of compressed air volume
to ensure that impacts on marine fauna were minimised.
• The lateral extent of marine seismic survey operations
was limited.
• Marine operations were conducted on high tides and
good weather to maximise safe access.
• The offshore component of the Survey was outside the
peak turtle nesting season.
• The marine operations were immediately adjacent and in
the shallow waters of the east side of Barrow Island out-
side of known cetacean migration routes, feeding and
breeding areas.
Implementing the Gorgon Project Quarantine Manage-
ment System
The Survey’s equipment and personnel were mobi-
lised to Barrow Island in accordance with the Gorgon Pro-
ject’s Quarantine Management System.
Extensive planning and early engagement of the
WesternGeco was critical as it enabled them to develop solu-
tions for some of the logistical issues faced. A mobilisation
strategy was developed that incorporated timing around
equipment cleaning, inspections and quarantine holding pe-
riods, as well as other initiatives including:
• Transporting equipment in sea containers where possi-
ble to enable easy fumigation.
• Redesigning the containers in which seismic cables and
other equipment were stored to minimize the risk of
contamination and to make inspection easier.
• Eliminating the use of wooden pallets or containers.
• Taking photographs of equipment as it was being disas-
sembled and cleaned as evidence of compliance with
quarantine requirements.
• At-source equipment inspections in the country of ori-
gin by a designated Quarantine Inspector.
A number of quarantine issues were observed dur-
ing at-source inspections in the country of origin and recti-
fied; this resulted in fewer impacts on the project schedule
because of non-conformances being identified on entry into
Australia or during mobilisation to Barrow Island. Figure 5
and 6 show seismic equipment in the process of being
wrapped, after a thorough cleaning and inspection, before
being fumigated and shipped to Barrow Island.
Management of Safety Risks
The Baseline Survey field activities on Barrow Isl-
and operated under the Barrow Island Safety Case. The
Seismic Baseline Survey Safety Case Bridging Document
formalized bridging interfaces between Barrow Island's
Safety Case, Chevron’s Safety Management Systems and
WesternGeco Quality Health Safety Environment (QHSE)
Management Systems.
The Safety Management System for Barrow Island
Operations is based on the Operational Excellence Manage-
ment System (OEMS) that operates at Chevron operations
worldwide. The WesternGeco QHSE (Quality, Health, Safe-
ty, and Environment) Management System is also based on
an integrated management system used by Schlumberger

5. SPE 132931 5
world-wide. Table 1 presents a list of QHSE targets set by
Chevron and WesterGeco management team for the baseline
seismic project.
The following health and safety risks were identified as
relevant to Baseline Survey activities during the planning
phase, and were managed well during operations:
• Helicopter operations
• Marine operations
• Drilling operations
• Manual handling
• Explosives handling
• Driving on Barrow Island
• Ultra Violet Radiation and heat exposure
• Hazardous substances and inventories
In addition to these recognized hazards, an underly-
ing risk in any activity is individual risk awareness, risk per-
ception and risk tolerance. This inherent risk in all activities
was managed through behavioral-based safety tools and site
leadership.
Manual Handling Risks
A number of tasks undertaken during the Survey
required a large amount of manual handling and physical
activity by the field crew including:
• Offloading and repacking of equipment at lay-down ar-
eas.
• Survey pegging.
• Packing and unpacking helicopter portable seismic bags.
• Laying out and picking up seismic recording equipment.
All personnel performing manual handling tasks
were trained to meet Chevron and WesternGeco require-
ments. This involved 6 hrs of Schlumberger Injury Preven-
tion Program (SIPP) training for all personnel involved in
the Survey, focusing on body mechanics and positioning for
proper manual handling and lifting. Personnel were issued
with appropriate Personal Protective Equipment (PPE), had
to be familiar with the Job Hazard Analysis (JHA) for the
task, and discussed such tasks in pre-start safety meetings.
The risk of manual handling incidents was reduced
by the use of mechanical lifting where possible, the helicop-
ter or forklift were used to unload and move equipment at
the staging areas. Where mechanical lifting devices were not
practical to use, then personnel manually handled appropri-
ate sized lifts.
Safety Planning in Helicopter Operations
Considerable effort and resources were expended
during the project planning phase to assess, identify, and
compile risk contingency plans for the helicopter operations.
The key safety management process utilized for addressing
risks and mitigations was the Helicopter ALARP (“As Low
As Reasonably Practicable”) demonstration that all reasona-
ble risk reduction measures were implemented. These were
consistent with industry practice, focused on known incident
causes and were subject to ongoing verification and review.
Commitments listed in the ALARP document were
verified during a pre-start, mid-job, monthly and weekly
ALARP checks. These audits were conducted by Chevron
Aviation and Health, Environment and Safety (HES) team
members.
The flight crew was managed by a very experienced
K-Max Chief Pilot with extensive long line experience.
Flight preparation was carried out with the assistance of
access to a flight planning computer, and the navigation and
drop zones were assisted by the aircraft Kodiac navigation
system.
All ground support crew were well trained and
equipped with high visibility tops, safety helmets, ear muffs,
eye-protection and each had communication with the air-
craft.
Vehicle Journey Management
To reduce risks to personnel and Barrow Island
fauna posed by increased use of vehicles, the number of per-
sonnel permitted to drive on Barrow Island was restricted.
A journey management system that met the
Schlumberger Journey Management and Driving Standard
001 was implemented during the Survey. A dedicated Jour-
ney Manager was responsible for monitoring and coordinat-
ing vehicle journeys, personnel in the field, coordinating
with the Kodiak Operator and the marine vessel.
The Journey Manager monitored VHF and UHF ra-
dios and the vehicle tracking system, which enabled them to
monitor the position of vehicles and personnel working on
the Survey.
Siemen’s VDO Fleet Manager 300 system was used
to monitor driver performance. Each vehicle used on the
Baseline Survey was fitted with a VDO driver-monitoring
device. This device was used to monitor individual drivers
parameters, including, time driving, over speeding, harsh
braking and harsh acceleration. When one of the set driving
parameters was exceeded an audible alarm sounded in the
cab of the vehicle and this event would be recorded on the
vehicle mounted VDO computer and reviewed.
Every second week, the WesternGeco QHSE Advi-
sor downloaded the driver monitoring data from the ve-
hicles. The data was analyzed against set parameters, the
results were entered into the WesternGeco’s database for
managing project information, Quest, and the results were
printed and displayed on the QHSE notice boards located at
the three staging areas.

6. 6 SPE 132931
In the case where drivers exceeded the set driving
parameters the individual/s involved would be counseled. If
the driver continued to exceed the set driving parameters,
they would have their authority to drive suspended.
Helicopter Journey Management
The GPS based Kodiak helicopter guidance, posi-
tioning and helibag management system was used to manage
helicopter operations. The Kodiak base computer was loaded
with the hi-resolution aerial photography, allowing the oper-
ator to set-up no-fly and hazard zones in areas of environ-
mentally sensitivity, power lines, towers and buildings. The
pilot is alerted by a warning message on his cockpit based
display when approaching a hazard zone (Figure 21). All of
the helicopter movements were pre-planned by the Kodiak
operator using the Kodiak Office system and sent to the pilot
as missions, these missions were logged in numerical and
graphics databases. A summary of the Kodiak log is pre-
sented in Table 3.
Fitness for Duty
Pre-employment medical examinations were con-
ducted on all personnel employed to work on the Baseline
Survey. The medicals were used to identify physical prob-
lems that would affect the ability of the candidate to fill the
position in a safe and effective manner. The structure and
content of the pre-employment medical was agreed by Wes-
ternGeco and Chevron. The pre-employment medical cov-
ered:
• Medical examination
• Audiometric and Vision
• Drug Testing
• Functional Fitness Assessment
Personal Protective Equipment (PPE)
As part of the planning for the project by the HES
management team , comprised of Chevron and Western Ge-
co specialists, a compulsory list of specific PPE was identi-
fied and provided to all employees and contractors involved
in the project. These PPE requirements were refined
through the experience gained during the Pilot Seismic Sur-
vey on Barrow Island in 2006 and further adapted as needed
during the 2009 Survey.
The PPE for Survey personnel included the more
typical PPE of safety boots with appropriate ankle support
for rough terrain, high visibility lightweight, long sleeve,
vented, cotton work shirts, long trousers, eye protection with
polarized lenses, hard hat, and gloves. In addition, work in
remote areas required 3-litre Camelback (drinking water
carried as backpack), rucksack, gaiters, fly nets, Arafat hats,
sunscreen (SPF 30+), wet suit boots for tidal zone, and first
aid kits.
As the project progressed, additional equipment
was required to mitigate the risks associated with compo-
nents of the Baseline Survey particularly as the ambient
temperatures increased and this included cooler bags for
food with ice bricks, aquiline rehydration powder, Camel-
back cleaning kit, sun hat, climbing harness, and carabi-
neers.
Figures 16, 17 and 18 are pictures of the Western-
Geco Crews working in the field and wearing the required
PPE. During the planning phase, it was recognized that per-
sonnel would be walking significant distances over rough
terrain on Barrow Island. All personnel were instructed to
provide their own boots, to be fully reimbursed by Western-
Geco, based on lessons learned during the 2006 Pilot Sur-
vey. This initial safety boot policy in the Survey was asso-
ciated with supplying new boots and subsequently, person-
nel suffering blisters while breaking new boots in on the
island. It was envisaged that personnel would arrive on Bar-
row Island with well fitting boots that had been broken in.
However, some of the short service employees purchased
lower quality boots and this may have contributed to the
incident involving a sprained ankle. The policy was then
modified to ensure that high-quality safety boots of specific
manufacture were directly supplied or reimbursed for pur-
chase by every project employee on the project.
Medical Support
Many of the Baseline Survey personnel visited the
Barrow Island medic on an as- needed basis for work-related
and non-work related medical issues. Work-related issues
were recorded and reported through the supervisor commu-
nication protocols for medical treatments.
The medics and facilities combined to provide a
good standard of remote emergency medical service. Two
medical evacuations (air ambulance to Perth) of Baseline
Survey personnel occurred during the project, both for non-
work related issues. The execution of these medical evacua-
tions and the medic jet service were excellent.
Dedicated medics would have been preferred to
sharing existing on island medics during the Survey. This
would have allowed the seismic team supervisors to have
improved the timely response to work-related medical issues
and specific communication on diagnosis, preventative ac-
tions and follow-up.
Inductions and Training
During the planning phase of the Survey Chevron
and WesternGeco personnel agreed on the minimum training
requirements for personnel working on the Survey on Bar-
row Island. A framework for delivery of inductions, on
boarding and specialized training for relevant disciplines
was planned. The minimum training requirements for both
WesternGeco and Chevron were assessed, mapped and dup-
lication avoided where practicable. A summary of the in-
duction and training requirements is presented in Table 2.

7. SPE 132931 7
Heat Stress Management
The physical environment on Barrow Island is con-
ducive to heat-related illness in personnel, particularly be-
tween October and March, where 40 degree Celsius plus
daytime temperatures and high humidity are common. The
Baseline Survey commenced in April and ceased in Novem-
ber, conditions during the last seven weeks were particularly
conducive to heat stress incidents. Pre-employment medical
examinations were conducted on all personnel employed to
work on the Survey. The medicals were used to identify
physical problems that would affect the ability of the candi-
date to fill the position in a safe and effective manner.
Prior to work commencing on Barrow Island for the
Survey, all personnel underwent a comprehensive induction
program raising awareness of the heat stress issue. Person-
nel were issued with appropriate clothing for the environ-
ment, including lightweight, long sleeve, vented, cotton
work shirts, long trousers, gloves, safety glasses, hardhat and
sunscreen. Where practicable, shade structures were made
available in or close to work areas.
The Survey was extended into the hotter months
leading to increased risk of heat related illness. This contri-
buted to one Medical Treatment Case where a crewmember
was given intravenous fluids by a medic due to dehydration
and suspected heat stress and one First Aid Case due to de-
hydration.
Considerable resources were focused on reducing
the risk of heat related illness including:
• All personnel received Chevron Heat Stress training.
• Personnel were deemed medically fit and having recently
completed a medical prior to arriving on the island.
• All personnel were issued with a 3-litre Camelback that
must be full at the start of the day. The replenishing of
water was ongoing throughout the day with strategically
placed water containers in areas remote from staging ar-
eas.
• Every seismic personnel were responsible for testing
themselves with the Urine Colour Coding System, placed
in toilets at the three staging areas and at the Barrow Is-
land camp.
• A buddy system was employed where personnel were
responsible to look out for their workmates and speak up
when they considered their workmate or themselves at
risk.
• Twice weekly, voluntary urine testing was conducted by
the on site Medic to indicate if personnel were maintain-
ing their hydration level.
• The subject of Heat Stress Management was raised on a
regular basis in the morning toolbox meetings, particu-
larly during the last seven weeks when temperature and
humidity increased.
• Journey management and Line Boss monitored the tem-
perature and humidity and used the Schlumberger Heat
Index Chart to cease work.
• Iced refreshments provided at break times during the
day.
• Helicopter portable cage containing drinking water, sun-
shade and seating was flown out for areas remote to
roads and tracks.
• Shaded and airconditioned facilities were made available
at staging areas to allow personnel shade during rest pe-
riods. Shade structures were fitted to drilling rigs.
Simultaneous Operations (SIMOPS)
Planning for the execution of the Baseline Survey
included mitigating SIMOPS conflicts. The risk of SIMOPS
was identified with the use of multiple helicopters working
and lifting in the same area. This risk was mitigated with
only one helicopter being utilized and only one lifting pro-
grammed to be conducted at a time. The planning process
was further supported by:
• Daily participation by the Chevron Geophysical Opera-
tions Advisor or delegate in the PIC and department
heads meeting on Barrow Island where SIMOPS is a ma-
jor focus.
• Frequent communications between the Chevron Geo-
physical Operations Advisor and the Gorgon Site HES
Representative regarding all operations within the Scope
of Work area.
• Use of the WA Oil Permit to Work system during the
Baseline Survey.
• Communications between seismic aviation subcontractor
and Barrow Island Airport Administrator (Approved Re-
porting Officer).
• No SIMOPS without a formal Risk Assessment and ap-
proval from the PIC and Chevron Geophysical Opera-
tions Advisor.
Working with Regulatory Authorities to Achieve Positive
Outcomes
Ongoing communication with regulatory authorities
during the Survey’s planning phase enabled best practice
outcomes for personnel, equipment and environment issues
that arose during the operational phase.
A compliance audit was conducted by the Depart-
ment of Mines and Petroleum and a ground disturbance and
compliance review was undertaken on field operations and
ground disturbance minimisation efforts by the Department
of Environment and Conservation. No major safety or envi-
ronmental issues or non-conformances were identified dur-
ing these audits.

8. 8 SPE 132931
Engaging the Field Crew
Significant ongoing efforts were made to provide
the field crew with an understanding of the unique Barrow
Island environment through ongoing awareness sessions, the
permanent presence of Safety and Environmental personnel
during operations, educational excursions and recognition
programs.
The field crews’ understanding and participation in
environmental initiatives was demonstrated by the efforts of
individuals including:
• Identification of potential quarantine issues (being
aware of the Barrow Island environment and reporting
locations of potentially abnormal flora or fauna for in-
spection by the Environmental Advisors)
• Proactive identification of high risk “leak” sites on
equipment and development of precautionary appropri-
ate containment and bunding controls
• Removal of any legacy waste observed in the field and
development of contractor waste reduction strategies
• Requests for additional environmental information ses-
sions
• Identification and mapping of new Burrowing Bettong
warrens, sensitive areas and environmental hazards by
the ground crew and helicopter pilot.
An environmental photography competition was in-
itiated to encourage the field crew to be aware of the Barrow
Island environment. Some of the photographs taken by the
crew were used in the Chevron Australia Annual Report.
Recognition Awards
The recognition and awards program used during
the Baseline Survey was designed to encourage and recog-
nize the superb efforts and achievements of individuals dur-
ing the Survey. Awards and recognition were given on a
regular basis at the weekly QHSE meeting and as spot
awards for both behaviors and accomplishments that im-
proved or complemented the safety and environmental cul-
ture of the Survey. Some examples included:
• Safety or Environmental Observations
• Effective communication
• Reducing at-risk safety and compliance behaviors
• Ingenuity
• Leadership
• Teamwork
• Improved work processes
• Sharing and adapting ideas
• Workforce empowerment
• Quality decision-making
• Environmental Stewardship
• Characteristics demonstrating accountability and owner-
ship
These recognition awards were often presented at
the pre-start safety meetings held in the WA Oil camp facili-
ty at predawn. During the sessions, ergonomic group
stretches were incorporated to prepare the team for the ri-
gours of manual handling and walking during the 12 hour
work days. These early morning sessions were morale
building, safety-focused and team motivating for the seis-
mic crews (Figure 19).
Key Lessons Learned
1. Even as familiarity for the overall safety culture
(i.e., “Do it safely or not at all”) was developed on
the seismic teams and with the project contractors,
it was necessary for the seismic leadership team to
routinely place added emphasis on the basic
framework elements such as daily safety observa-
tions, proactive interventions, stop work authority,
and tool box safety talks.
2. Extra care and effort was taken to improve the crew
morale and comforts in camp to compensate for
long hours in the field. Examples were BBQs, team
sports in the evening, new flat screen TVs, special
lunches in the field, and photo competitions.
3. Although the project did not have dedicated medics
(working instead with the existing oilfield medical
care system), the seismic leadership team was
agreed that the project would have benefited from
dedicated medics.
4. As a key learning from the project, extra effort was
made to ensure that the medics were aware of spe-
cial risks for the Survey including walking over ha-
zardous terrain (e.g. foot blisters, ankle injuries),
manual handling and dehydration.
5. The pre-employment medical screens attempted to
address all the physical rigors of working in a harsh
environment to mitigate risk for manual handling
and heat stress.
6. A set of standardized PPE requirements was issued
to all contractors and employees on the job. As the
project execution progressed, the list of PPE
evolved to include better quality boots, sun hats (in-
stead of hard hats in remote areas), larger camel
backs, specialized gloves, and better leg protection
from spinifex.
7. Job hazard analyses (JHAs) need to be reviewed on
a regular basis, and not just after incidents. JHA
reviews on the job site should be concise, meaning-
ful, and focused discussions on the job risks at hand
and not just a “reading” of the generic JHA.

9. SPE 132931 9
8. There is no replacement for at least daily communi-
cation meetings with key contractors and support
crews. These regular meetings were structured
around meaningful discussions on job risks, obser-
vations and interventions to reduce job hazards and
raise awareness.
9. The WesternGeco vehicle journey management
system was especially effective in achieving a near-
ly blemish-free driving record during the project.
Enablers of this successful program included VDO
monitors, specific driving training, GPS tracking,
monthly posting of driver scores, radio monitoring,
parking lanes, and recognition of good driving
records.
10. Due to late onboarding of some of the key leader-
ship team, it was not possible for induction of all
new supervisors into the Chevron Way culture and
engagement with other team leaders. Making time
for teambuilding with all contractor and project
team leaders is recommended prior to mobilization.
11. Drilling progress was slower initially than was
forecast. The drilling contractor was given space to
solve the issue through innovation of new bit de-
signs and the implementation of foam assist drill-
ing. This approach was chosen over taking reactive
measures that would have pressured the contractor
to rush his work and potentially compromise the
safety performance and culture.
12. The Survey execution was challenged early by a
lack of adequate laydown room for all seismic
equipment due to complex land use and tenure re-
strictions for Barrow Island. Figure 20 is an aerial
view of the main seismic equipment laydown area
on Barrow Island, for the Survey, on a location that
was annexed by a Section 91 extension after project
mobilization. A key lesson re-learned is to ade-
quately assess the equipment laydown footprint for
safe operations.
13. To achieve the best environmental outcome it was
essential to work with the regulatory agencies to al-
low for real-time movement of vibroseis lines and
seismic shot points to avoid unique flora and fauna
habitats identified during the course of the Survey
given the complex regulatory and tenure regime on
Barrow Island. Figure 4 shows an aerial view of a
vibroseis line that has been altered to avoid fauna
habitats with appropriate regulatory approvals.
14. All seismic team members were empowered and
trained to exercise SWA (Stop Work Authority) at
any time that an unsafe condition or behavior was
observed on the project site. These SWA’s were
often recognized by the seismic leadership team
during the recognition and awards programs.
Conclusions
The execution of the Survey was achieved while
meeting its geophysical, environmental and operational ob-
jectives including:
• Acquisition of quality seismic data able to be effectively
used in injection planning and as a baseline for monitor-
ing the injected CO2.
• Survey execution with minimal ground disturbance and
environmental impacts (less than 19 hectares of ground
disturbance).
• An excellent health and safety performance considering
the risk exposure that personnel faced during the Sur-
vey. The final project safety record resulted in three
minor restricted work cases and one medical treatement
case. In each case, the injured personnel were proac-
tively managed and all received medical clearances to
return to duty with no restrictions.
• Inclusion of environmental considerations into every
aspect of the Survey from design to execution.
• Commitment to stakeholder engagement including early
engagement of expert contractors to assist in design, en-
gagement of regulatory authorities throughout planning
and execution and extensive engagement of the field
crew during operations to achieve best-practice out-
comes.
Acknowledgements
The authors would like to graciously thank the
management of Chevron and its Joint Venture Participants
ExxonMobil, Shell, Osaka Gas, Tokyo Gas and Chubu Elec-
tric Power for permission to publish this paper. The authors
would also like to acknowledge WestermGeco and the wide
range of Contractor and Chevron personnel who contributed
significantly to the success of this Survey. Many thanks are
also extended to the Chevron Gorgon CO2 Seismic Baseline
Survey Team who supportedthe successful execution of the
Survey including Amie Martin, Tony O’Keeffe, Travis
Dearborne, Jason Seabrook, Kym Ash, Steve May, Terry
Grocke, and Paul Jelley.

10. 10 SPE 132931
References
1. Clulow, Bruce & Coetzee, Justine; “Cleaner and Greener; Environmental Mastery in a “Class A” Nature Reserve. Wavefront, tri-annual
publication of WesternGeco, Vol 1, 2010.
2. Flett, Matt; Beacher, Graeme; Brantjes, SPE, et al. “Gorgon Project: Subsurface evaluation of carbon dioxide disposal under Barrow Is-
land”; presented at the 2008 SPE Asia Pacific Oil & Gas Conference and Exhibition, Perth, Australia, 20-22, Oct, 2008. SPE 116372.
Nomenclature
3D Three Dimensional
ALARP As Low As Reasonably Practicable
CO2 Carbon Dioxide
GPS Global Positioning System
HES Health, Environment, and Safety
JHA Job Hazard Analysis
LNG Liquefied Natural Gas
LiDAR Light Detection and Ranging
MTC Medical Treatment Case
MTPA Million Tonne per Annum
OEMS Operational Excellence Management System
OSPREY Observation Safety Protects Resources, Equipment, and You
PIC Person in Charge
QHSE Quality, Health, Safety & Environment
RIR Risk Identification Report
RWC Restricted Work Case
SIMOPS Simultaneous Operations
SIPP Schlumberger Injury Prevention Program
SWA Stop Work Authority
TIF Think Incident Free
UHF Ultra High Frequency
VDO Vehicle and Driver Observation
VHF Very High Frequency
WA Western Australia
WAPET Western Australia Petroleum

11. SPE 132931 11
Figure 1: Map of the Gorgon Project in Northwest Australia.
Figure 2: Diagram of development concept for CO2 injection into a saline aquifer below Barrow Island.

12. 12 SPE 132931
Figure 3: Overview of the 2009 3D CO2 Seismic Baseline Survey on Barrow Island. Legend indicates location of shot point drilling, vi-
broseis, and shallow marine survey. Also, the 5 year predicted CO2 plume is outlined in yellow.

13. SPE 132931 13
Figure 4: Aerial view of a vibroseis track on Barrow Island showing excursion around Burrowing Bettong warrens (green) and termite
mounds (orange triangles) as habitats were encountered during the survey.

14. 14 SPE 132931
QHSE Objectives Performance
Leadership and Commitment
Line Management complete a minimum of 4 documented Site Audits. 100%
Line Management to complete a minimum of 3 documented driving observations and interventions per quarter 100%
Line Management to complete a minimum of 6 documented non-driving observations and interventions per quarter 100%
Implement a Managers Scorecard for all fulltime WesternGeco personnel and review monthly 100%
Injury Prevention
Assess Injury Prevention standard and obtain a level 2 compliance in all locations 100%
Crew to complete a minimum of 3 Observation and Intervention per quarter 100%
Complete investigations all accidents and all high potential incidents within 60 days of the incident date 100%
At least 80% of RWP events report closure within 60 days 100%
Driving
Zero driving incidents 21%
Driver monitors installed in all vehicles 100%
Complete a Journey Management audit and obtain a minimum level 2 compliance 100%
Risk Management
Define all key operational risks through the HARC process and publish in inTouch 100%
Learning from Incidents process implemented on project 100%
Training/Certification
Define and post the Training Matrix for crew staff 100%
Maintain 100% compliance with WesternGeco minimum training 100%
Maintain >90% compliance with job related training 100%
Achieve >95% coverage of crew with fatigue management roll out and level 1 training 100%
Environment
No quarantine infringements 100%
Inspections and audits documented in QUEST (Implementation of ECOSEIS) 100%
Complete self assessment audit and achieve grade 1 or 2 100%
Health
All staff will have a valid medical 95%
Implement a heat stress campaign 100%
HSE Communications
Alerts reviewed with staff and posted on QHSE notice boards 100%
Table 1 WesternGeco QHSE Targets and Results

15. SPE 132931 15
Figure 5: WesternGeco Vibroseis being wrapped after thorough cleaning for transport by truck and barge to Barrow Island.

16. 16 SPE 132931
Figure 6: Portable buildings completely sealed, fumigated upon initial arrival to Barrow Island.

17. SPE 132931 17
Figure 7: Kaman K-max medium lift helicopter taking off from the staging area seismic helipad on Barrow Island.

18. 18 SPE 132931
Figure 8: A pair of WesternGeco vibroseis trucks getting ready to run a seismic line on Barrow Island.

19. SPE 132931 19
Figure 9: An aerial view of a vibroseis truck showing the minimal footprint impact on the vegetation on Barrow Island from the specially
modified track on the trucks.

20. 20 SPE 132931
Figure 10: A Websters shot hole drilling rig showing the detail of the air percussion and sonic drilling head as it picks up a drill rod for
drilling a shot hole.

21. SPE 132931 21
Figure 11: Five of the six Webster’s Seismic Shot Hole Drilling Rigs drilling on a single seismic source line.

22. 22 SPE 132931
Figure 12: The Kmax lifting a rig component to mobilize to the next shot hole location.

23. SPE 132931 23
Figure 13: Helicopter view of the KMax safely landing one component of the seismic drill rig, taking advantage of selective placement on
a rocky ledge to minimize disturbed land and flora.

24. 24 SPE 132931
Figure 14: The converted, shallow-water air-gun seismic vessel, Aimee, at anchor in Exmouth, WA.

25. SPE 132931 25
Figure 15: The seismic vessel tender, Tomahawk, was provided for safe sea to land transfer of seismic crew traveling back to Barrow
Island from the Aimee seismic vessel . Shown at a jetty facility on Barrow Island.

26. 26 SPE 132931
Figure 16: Western Geco crew deploying seismic arrays near a WA Oil pumping unit.

27. SPE 132931 27
Figure 17: Western Geco seismic team manually carrying and deploying seismic cables and geophones into receiver arrays.

28. 28 SPE 132931
Figure 18: Line crew unloading cables and geophones, from a helipoprtable bag, for deployment to the seismic project area.

29. SPE 132931 29
Figure 19: Morning pre-start safety meeting with the seismic crew warming up with team ergonomics. Proper stretching and specific
exercises were neccessary for the crew to safely prepare for the daily rigours of carrying seimic equipment and walking long distances
across the rugged terrain of Barrow Island.

30. 30 SPE 132931
Figure 20: K-Max camera shot showing the seismic equipment layout, including rows of coiled cable, vibrosies trucks and sea contain-
ers.

31. SPE 132931 31
Figure 21: Kodiak Office Mission showing no-fly hazard zones around overhead power lines.
Requirement Contractor When Details Conducted By Duration
Barrow Island Induction / Northwest
Core
Prior to work com-
mencing
All persons who enter
Barrow Island
Chevron Australia 4 hours
DTEC Off-road Driver Training or
equivalent Schlumberger Drive
Smart Training
Prior to work com-
mencing
All employees who will
drive a vehicle on Bar-
row Island
DTEC or WesternGeco 1 day
Permit to Work Prior to working under
a Permit to Work Sys-
tem
All employees working
under a Permit
ERGT 1 day
JHA Training Prior to working under
a Permit to Work Sys-
tem
All employees working
under a Permit
ERGT ½ day
Gas Detector Training Prior to drilling opera-
tions
All employees on drill-
ing rigs
ERGT ½ day
Permit Holder Training Prior to drilling or
loading of explosives
works
Drillers and shotfiring
teams
ERGT 2 days
Heat Stress Training Prior to work com-
mencing
All personnel Chevron Australia 2 hours
Helicopter Induction Prior to working near
helicopters
Personnel working near
helicopters
Aviation company 1 hour
Incident/Injury Free Orientation Prior to work com-
mencing
All Contractor personnel Chevron Australia 4 hours
Project Induction Prior to work com-
mencing
All personnel WesternGeco and Che-
vron
3 hour
Quarantine Compliance Training Prior to work com-
mencing
All Persons who enter
Barrow Island
Chevron Australia 3 hour

32. 32 SPE 132931
Schlumberger Injury Prevention
Program
Prior to work com-
mencing
All WesternGeco and
Subcontractor personnel
WesternGeco 6 hours
Visitors Induction On arrival to Barrow
Island
All Visitors Chevron Australia 30 minutes
Responsible Operator Training Prior to signing off on
a Work Permit
Selected Chevron Per-
sonnel
ERGT 2 days
Environmental Induction Prior to work com-
mencing
All WesternGeco and
Subcontractor personnel
Chevron Australia 1 hour
Weed Awareness Induction Prior to work com-
mencing
All WesternGeco and
Subcontractor personnel
Chevron Australia 40 minutes
Marine Fauna Observation Prior to marine work
commencing
Selected marine person-
nel
RPS Consultant 1 day
Asbestos Awareness Prior to work com-
mencing
All WesternGeco and
Subcontractor personnel
Chevron Australia 40 minutes
Schlumberger Injury Prevention
Program (SIPP)
Prior to work com-
mencing
All WesternGeco and
Subcontractor personnel
WesternGeco 3 hours
Observation/Intervention Prior to work com-
mencing
All WesternGeco and
Subcontractor personnel
WesternGeco 3 hours
Table 2: Inductions and Training Matrix for 2009 Gorgon CO2 Seismic Baseline Survey

33. SPE 132931 33
Month
Total Fly Hours Total Kms. A1 JetFuel
Refuel
Runs
Total
Drops
Total Pickups Total Extras Total Missions
May 2009 37:36 2,448 13,395 36 152 48 1 201
June 2009 91:30 9,828.14 33,368 95 1,387 465 50 1,902
July 2009 141:30 9,624.16 49,947 132 2,608 55 301 2,964
August 2009 236:18 15,128.72 82,399 176 4,561 360 224 5,145
September 2009 219:36 13,387.15 73,026 202 3,595 1,076 288 4,959
October 2009 128:42 8,217.88 43,743 93 1,829 3,748 28 5,605
November 2009 62:36 3,773.27 19,034 25 115 4,433 29 4,577
TOTALS 917:48 62,407.32 314,912 759 14,247 10,185 921 25,353
Table 3: Summary of Helicopter Kodiak Missions