UNITED STATES GOVERNMENT MEMORANDUM

To: Public Information (MS 5030)

Plans Section, Office of Field 

Operations (MS 5231)

Public Information copy of Exploration Plan

Control # - R-05105

Type - Revised Exploration Plan

Lease(s) - OCS-G32509 Block - 451 Green Canyon Area

Operator - Woodside Energy (USA) Inc.

Subsea Wells A, B, and C

DP SEMISUBMERSIBLE

Attached is a copy of the subject plan for public comments on issues that 

should be addressed in an Environmental Assessment.

It has been deemed submitted as of this date and is under review for approval.

Karen Dunlap

Plan Coordinator

Description -

Rig Type -

Subject:

From:

September 29, 2011
Woodside Energy (USA) Inc.

Green Canyon Block 451OCS-G-32509 #A-CRevised Initial Plan (Floyd)Control No. R-5105 Timesheet is for Public & Proprietary Versions.SUBMISSION TYPE PAGE # APPENDIX DATE 

SUBMITTED

DATA SUBMITTED

Submitted Initial Plan. Plan approved 11/5/09. 9/16/09Submit revised Plan due to NTL 2010 G-09 and WCD 7/21/10Amendment 7/22 & 27/10 WCD & Blowout ScenarioAmendment No longer required due to change in WCD Scenario.Amendment 1/6/11 Submit with NEPA information, LCZMAmendment 1/18/11 Replaced Plan with revisions to dateAmendment 1, 1, 2, 1-2 5/11/11 Update OCS Plan Information, Bath Maps, Table of 

tanks/production vessels more than 25 bbls capacity , Description of the important safety and pollution prevention features for drilling unit. 

Amendment 17 5/11/11 Oil Spill Discussion: Owner of Equipment, 

Insufficient Containment, Skimmers, Storage and Booms.

Amendment 3, 3, 4, 5, 6, 

11, 13-14, 15,22, 22, 23, 23,24,

A 5/11/11 Applications & Permits, Drilling Fluids, Blowout 

Scenario, Shallow Hazards Report, Archaeological Report, Waste & Discharge Tables, AQR Revision, Support Vessels, Diesel Oil Supply Vessels, Drilling Fluids and Solid & Liquid Waste Transportation, LA CZM, Plan Information Form.
Woodside Energy (USA) Inc.

Green Canyon Block 451OCS-G-32509 #A-CRevised Initial Plan (Floyd)Control No. R-5105 Timesheet is for Public & Proprietary Versions.SUBMISSION TYPE PAGE # APPENDIX DATE 

SUBMITTED

DATA SUBMITTED

Amendment 13 05/11/11 Downhole injection & NPDES General Permit 

Statements at Waste and Discharge Information (a)

Amendment 05/16/11 Revised Plan Information Form with Revised DatesAmendment 4 5/19/11 WCD assumptions and calculations for AT 187

Amendment 4 5/23/2011 WCD assumptions for GC 451 & AT 187

Amendment 4 6/7/2011 Revised Discharge Table adding BOP fluids, etc

Amendment 4 6/8/2011 Volume of daily discharge rate for WCDS.

Amendment 22 6/15/2011 Diesel oil fuel supply vessels

Amendment 15 6/27/2011 Air Emissions & Plan Information Plan revision

Amendment 15 6/29/2011 AQR checklist & summary sheet

Amendment 9, 16, A, B, D, E, F, 

G, I

8/02/11 Deepen wells: H2S, OSRO Information, Well 

Information Form, Location Plat, Time vs. Depth, Structure Map, Seismic Lines, Cross Section, Strat. Column

Amendment N 8/18/2011 Surface containment timeAmendment 9/7/2011 Submittal of complete Plan w/ containment plan 

acceptance statement added.

Amendment A, N 9/12/2011 Submittal of Plan Information Form & surface 

containment time
Woodside Energy (USA) Inc.

Green Canyon Block 451OCS-G-32509 #A-CRevised Initial Plan (Floyd)Control No. R-5105 Timesheet is for Public & Proprietary Versions.SUBMISSION TYPE PAGE # APPENDIX DATE 

SUBMITTED

DATA SUBMITTED

Amendment 9/13/2011 Revised footers on public version.Amendment 9/14/2011 New log and 2nd complete copy of PlanAmendment 9/21/2011 New log and revised p. 16
Woodside Energy (USA) Inc. 1 Green Canyon Block 451 

Initial EP 

Revised 1-6-2011 Lease OCS-G 32509 

Revised Exploration Plan 

Woodside Energy (USA) Inc. 

Green Canyon Block 451 

Leases OCS-G 32509 

January 11, 2011 

CONTENTS OF PLAN

Under this Initial EP, Woodside Energy (USA) Inc. (Woodside) plans to drill and temporarily 

abandon three (3) wells (Locations A ,B, & C ) in Green Canyon Block 451, Lease OCS-G 

32509. A subsea Blowout Preventer (BOP) will be used in this operation. This Plan was originally

given Control No. N-9436 and the revision was given Control No. R-5105

(a) Plan Information Form 

 

An OCS Information Form with details of the proposed drilling operations as provided for in this 

Plan along with a tentative schedule is included as Attachment A. 

(b) Bathymetry Map, Location Plat , Anchor Pattern, and Anchor Site Clearance

A Well Location Plat and a Bathymetry Map are included as Attachments B and C, 

respectively. 

There are no anchors associated with this plan.

(c) Safety and Pollution Prevention Features

Safety features on the MODU will include well control, pollution prevention, welding procedure, 

and blowout prevention equipment as described in Title 30 CFR Part 250, Subparts C, D, E, G 

and O; and as further clarified by MMS Notice to Lessees, and current policy making invoked by 

the MMS, Environmental Protection Agency and the U.S. Coast Guard. The appropriate life 

boats, life rafts, life jackets, ring buoys, etc., as prescribed by the U.S. Coast Guard will be 

maintained on the facility at all times. 

In accordance with Title 30 CFR Part 250, Subpart O, an operator is to ensure Well Control 

Training is provided for lessee and contractor personnel engaged in well control operations in 

the OCS Gulf of Mexico. Further, the operator is charged with the responsibility to not create 

conditions that will pose unreasonable risk to the public health, life, property, aquatic life, 

wildlife, recreation, navigation, commercial fishing, or other uses of the ocean. 
Supervisory and certain designated personnel on-board the facility are to be familiar with 

the effluent limitations and guidelines for overboard discharges into the receiving waters, 

as outlined in the latest NPDES General Permit GMG290000. Some of these pollution 

prevention measures include installation of curbs, gutters, drip pans, and drains on 

drilling deck areas to collect all contaminants and debris. 

The MMS is required to conduct onsite inspections of offshore facilities to confirm 

operators are complying with lease stipulations, operating regulations, approved plans, 

and other conditions; as well as to assure safety and pollution prevention requirements 

are being met. The National Potential Incident of Noncompliance (PINC) List serves as 

the baseline for these inspections. The MMS also inspects the stockpiles of equipment 

listed in the operator's approved Oil Spill Response Plan that would be used for the 

containment and cleanup of hydrocarbon spills. 

(d) Storage Tanks and Production Vessels

Tanks on the Maersk Developer with a capacity of 25 bbls or more of oil as defined in 30 

CFR 254.6 are listed below:

Type of 

Storage Tank

Type of 

Facility 

Tank Capacity 

(bbls) 

Number 

of Tanks 

Total 

Capacity 

(bbls) 

Fluid 

Gravity 

(API)

Hull tanks 1&2 Fuel oil (Diesel) 8204 2 16408 32 o 

Hull tanks 3&4 Fuel oil (Diesel) 5500 2 11000 32o 

Engine day tank P Fuel oil (Diesel) 305 1 305 32o 

Engine day tank S Fuel oil (Diesel) 356 1 356 32o 

Settling tank P Fuel oil (Diesel) 213 1 213 32o

Settling tank S Fuel oil (Diesel) 219 1 219 32o

Base oil 1 Lube oil 4838 1 4838 30o

Lubrication oil Lube oil 55 1 55 32o 

Waste oil 1&2 Waste oil 226 2 452 31o 

(e) Pollution Prevention Measures 

The Maersk Developer is rigged up for 100% zero discharge operations. All rainwater, 

wash water, or fluid spillage or runoff is captured and treated via an oil/water separator. 

Only the uncontaminated water is discharged overboard. The contaminated fluids are 

transported to the shore base for disposal. All trash is compacted and bagged and 

transported to the shore base for disposal 

(f) Additional Measures

No additional measures are proposed for this Plan. 
Woodside Energy (USA) Inc. 3 Green Canyon Block 451 

Initial EP 

Revised 1-6-2011 Lease OCS-G 32509 

GENERAL INFORMATION

(a) Applications and Permits

Application / Permit Issuing Agency Status 

APD BOEMRE District To be submitted 

General NPDES Permit U.S. EPA To be submitted 

Emergency Evacuation Plan U.S. Coast Guard To be submitted 

 (b) Drilling Fluids

Type of Drilling Fluid Est. Vol. of Drilling Fluid per Well 

Water-based 36,000 bbls 

Synthetic-based 15,000 bbls 

Oil-Based 0 bbls 

(c) Peak Production Rates / Life of Reserves

Not applicable for exploration plans. 

(d) Oil Characteristics

Not applicable for exploration plans. 

(e) New or Unusual Technology

Woodside does not propose the use of any new or unusual technology in the activities proposed 

under this plan. 

(f) Bonding Information 

The bond requirements for the activities and facilities proposed in this Initial EP are satisfied by 

an area-wide bond furnished and maintained according to 30 CFR Part 256, Subpart I; NTL No. 

2000-G16, “Guidelines for General Lease Surety Bonds”; and National NTL No. 2008-N07. 

(g) Oil Spill Financial Responsibility (OSFR)

Woodside (MMS Operator No. 02407) has demonstrated oil spill financial responsibility for the 

facilities proposed in this Initial EP according to 30 CFR Part 253, and NTL 2008-N05, 

“Guidelines for Oil Spill Financial Responsibility for Covered Facilities”. 

(h) Deepwater Well Control Statement
Woodside Energy (USA) Inc. 4 Green Canyon Block 451 

Initial EP 

Revised 1-6-2011 Lease OCS-G 32509 

Woodside (MMS Operator No. 02407) has the financial capability to drill a relief well and 

conduct other emergency well control operations. 

(i) Suspensions of Production

Not applicable for exploration plans. 

 (j) Blowout Scenario

A blowout scenario for the proposed operations is outlined in Attachment L. 

 (k) Chemical Products

This information is not required for the activities proposed in this plan in the MMS GOMR. 
GEOLOGICAL AND GEOPHYSICAL INFORMATION

In accordance with 43 CFR 2.13 (c) (9), those items considered proprietary have 

been omitted from the Public Information copy and have been referenced 

accordingly. 

(a) Geological Description

PROPRIETARY 

(b) Structure Contour Maps 

Enclosed as Attachment E are current structure maps drawn to the top of the 

proposed hydrocarbon zone(s). The surface and bottom hole location(s) along with 

the locations of the geologic cross-sections of the well(s) to be drilled under this Initial 

EP are included. 

(c) Interpreted 2-D or 3-D Seismic Lines

Enclosed as Attachment F are copies of the migrated and annotated deep seismic 

line within 500 feet of each of the proposed surface locations. 

(d) Geological Structure Cross-Sections

An interpreted geological cross-section showing the location and depth of each of the 

proposed well(s) with at least one key horizon and the objective sand labeled is 

enclosed as Attachment G. 

(e) Shallow Hazards Report

Geoscience Earth & Marine Services, Inc (GEMS) was contracted by Woodside 

Energy (USA) Inc. to provide a 3D Geohazard review study in the Atwater Valley 

area of the Gulf of Mexico to investigate seabed and subseabed geohazards across 

Block 187, Offshore, Louisiana in May 2010. The purpose of the study was for the 

identification of potential shallow drilling hazards and problems which may impact the 

rig positioning or drilling of proposed exploratory well and for possible anchor 

moorings. 

Three (3) copies of the report and maps prepared by GEMS were included in the 

Plan’s original submittal. 
Woodside Energy (USA) Inc. 6 Green Canyon Block 451 

Initial EP 

Revised 1-6-2011 Lease OCS-G 32509 

(f) Site Specific Shallow Hazards Assessment

C&C was contracted by Woodside Energy (USA) Inc. to provide a 3D Geohazard review study 

in the Green Canyon area of the Gulf of Mexico to investigate seabed and sub-seabed 

geohazards across Block 451, Offshore, Louisiana, in April 2009. The purpose of the 

assessment was to address seafloor and shallow geologic conditions that may impact 

exploratory drilling operations within 2000 feet of the proposed wellsites. This site clearance is 

based on the interpretation of 3D seismic data provided by Woodside to C&C. 

Copies of the site clearance for each proposed location are included with this plan as 

Attachment H to assist your review. 

(g) High Resolution Seismic Lines

C&C was contracted by Woodside Energy (USA) Inc. to provide a 3D Geohazard review study 

in the Green Canyon area of the Gulf of Mexico to investigate seabed and sub-seabed 

geohazards across Block 451, Offshore, Louisiana, 2009. The purpose of the assessment was 

to address seafloor and shallow geologic conditions that may impact exploratory drilling 

operations within 2000 feet of the proposed wellsite. This site clearance is based on the 

interpretation of 3D seismic data provided by Woodside to C&C. 

(h) Stratigraphic Column 

A generalized biostratigraphic/lithostratigraphic column from the seafloor to the total depth of 

each of the proposed well(s) is included as Attachment I. 

(i) Time Versus Depth Tables 

Time versus depth tables are included as Attachment D.

 

(j) Geochemical Information

This information is not required for the activities proposed in this plan in the MMS GOMR. 

(k) Future G&G Activities

This information is not required for the activities proposed in this plan in the MMS GOMR. 
HYDROGEN SULFIDE INFORMATION

(a) Concentration

Woodside does not anticipate encountering H2S while conducting our proposed 

exploratory activities. 

(b) Classification Request

In accordance with Title 30 CFR 250.490(c), Woodside requests Green Canyon Block 

451, Lease OCS-G 32509, be classified by the Minerals Management Service as an 

area where the “absence” of hydrogen sulfide has been substantiated based upon the 

following: 

PROPRIETARY 

 

(c) Contingency Plan 

Woodside does not anticipate encountering H2S while conducting our proposed 

exploratory activities therefore a contingency plan is not required at this time. 

(d) Modeling Report

Woodside does not anticipate encountering H2S while conducting our proposed 

exploratory activities therefore a modeling report is not required at this time. 
Woodside Energy (USA) Inc. 8 Green Canyon Block 451 

Initial EP 

Revised 1-6-2011 Lease OCS-G 32509 

Mineral and Resource Conservation Information

(a) Technology and Reservoir Engineering Practices and Procedures

Not Required for Exploration Plans 

(b) Technology and Recovery Practices and Procedures

Not Required for Exploration Plans 

(c) Reservoir Development

Not Required for Exploration Plans 
Woodside Energy (USA) Inc. 9 Green Canyon Block 451 

Initial EP 

Revised 1-6-2011 Lease OCS-G 32509 

BIOLOGICAL, PHYSICAL AND SOCIOECONOMIC INFORMATION

(a) Chemosynthetic Communities Report

C&C performed a geohazards assessment for the “Floyd” Prospect located in Block 451(OCSG-32509) and vicinity, Green Canyon Area, Gulf of Mexico using a 3D seismic data volume 

provided by Woodside in June 2009. The purpose of the assessment was to address seafloor 

conditions that may impact exploratory drilling operations within 2000 feet of the proposed 

wellsite. 

Water depths of the study area are greater than 300 meters (984 feet). No chemosynthetic 

communities have been reported in the area according to the MMS (NTL No. 2000-G20). The 

nearest chemosynthetic communities known to exist are located in GC-272 and 232, 

approximately 12 miles northwest of the survey area. 

C&C was also contracted by Woodside Energy (USA) Inc. to prepare site clearance letters for each 

of the proposed drill sites in Block 451, Green Canyon Area, Offshore, Louisiana. These can be 

found with our shallow hazards assessment in Attachment H. Woodside does not anticipate any 

seafloor conditions that may impact exploratory drilling operations within 2000 feet of the proposed 

wellsite(s). 

(b) Topographic Features Map 

There are no proposed bottom-disturbing activities within 1000 feet of the “No Activity Zone” of 

an identified topographic feature. 

(c) Topographic Features Statement 

Woodside does not propose to drill more than two wells from the same surface location which is 

outside the 1-mile Zone but within the Protective Zone of an identified topographic feature; 

therefore a statement for shunting described in Attachment 2, Section A, Item No. 2 of NTL No. 

2004-G05 “Biologically Sensitive Areas of the Gulf of Mexico” is not required. 

(d) Live Bottom (Pinnacle Trend) Map 

The activities proposed in this plan are not affected by a live bottom (pinnacle trend) stipulation 

attached to the lease. 

(e) Live Bottom (Low Relief) Map 

The activities proposed in this plan are not affected by a live bottom (low relief) stipulation 

attached to the lease. 
Woodside Energy (USA) Inc. 10 Green Canyon Block 451 

Initial EP 

Revised 1-6-2011 Lease OCS-G 32509 

(f) Potentially Sensitive Biological Features

Woodside does not propose bottom-disturbing activities within 61 meters (200 feet) of 

potentially sensitive biological features; therefore the map described in Attachment 8, Section A, 

of NTL No. 2009-G39 “Biologically Sensitive Underwater Features & Areas” is not required. 

(g) ROV Monitoring Survey Plan

The activities proposed in this plan do not require an ROV Survey Plan since the Deepwater 

Grid (Grid 10) accessed through NTL 2008-G06 shows sufficient ROV information has been 

gathered for the GC-451 area. 
Woodside Energy (USA) Inc. 11 Green Canyon Block 451 

Initial EP 

Revised 1-6-2011 Lease OCS-G 32509 

(h) Threatened and Endangered Species Information

The Marine Mammal Protection Act (MMPA) established a moratorium on the taking of marine 

mammals in U.S. waters. It defines “take” to mean “to hunt, harass, capture, or kill” any marine 

mammal, or attempt to do so. Marine mammals protected under the MMAP that may be found 

in the location of the activities proposed include: 

Sperm Whales, Blue Whales, Sei Whales, Sin Whales, Humpback Whales and North Atlantic 

Right Whales, of these six whales, only Sperm Whales are considered to commonly occur in the 

Gulf of Mexico. Bottlenose Dolphin, Atlantic Spotted Dolphin, and Risso’s Dolphin are 

considered protected species and are also regarded to be common “nearshore species”. 

The purpose of the Endangered Species Act (ESA) is to conserve threatened and endangered 

species and their ecosystems. A species is considered endangered if it is in danger of extinction 

throughout all or a significant portion of its range. A species is considered threatened if it is likely 

to become endangered in the future. The location of the activities proposed in this plan does not 

include any critical habitats designated under the ESA. Threatened and endangered turtles that 

may be found in the location of the activities proposed include: 

Green Sea Turtles, Hawk’s Bill Sea Turtles, Kemp’s Ridley Sea Turtles, Leatherback Sea 

Turtles, and Loggerhead Sea Turtles. 

Other threatened or endangered species that may be found in the area of proposed activities 

but are more commonly found in coastal areas or estuaries include: 

Gulf Sturgeon and Smalltooth Sawfish. 

Threatened nearshore marine invertebrates species include: 

Elkhorn Coral and Staghorn Coral 

The Dusky Sharks, Night Sharks, Sand Tiger Sharks, Speckled Hind, Warsaw Grouper, and 

Nassau Grouper are all considered “species of concern”. Please refer to our Environmental 

Impact Analysis (EIA) contained in this plan for detailed information on how Woodside plans to 

mitigate harm to these threatened and endangered species. 

(i) Archaeological Report

Woodside will perform an ROV survey imaging 100% of the seafloor with sector scanning sonar 

within a minimum 500’ radius of the proposed well locations upon commencement of 

operations. These locations will be certified by an authorized marine archaeologist and by 

Woodside to be clear of seafloor archaeological resources, including historic shipwrecks. 

Copies of the certifications and a circle radius plat of the survey area will be submitted to the 

BOEMRE. Should a resource be encountered, Woodside will contact the BOEMRE 

immediately. 

(j) Air and Water Quality Information

The location of the activities proposed in this plan do not affect the State of Florida; therefore 

this information is not required in this plan. 
Woodside Energy (USA) Inc. 12 Green Canyon Block 451 

Initial EP 

Revised 1-6-2011 Lease OCS-G 32509 

(k) Socioeconomic Information

The location of the activities proposed in this plan do not affect the State of Florida; therefore 

this information is not required in this plan. 
WASTE AND DISCHARGE INFORMATION

(a) Projected Ocean Discharges See Table 1 below. There will be no downhole 

disposal. These discharges will be covered by a general NPDES discharge permit.

(b) Projected Generated Wastes See Table 2 below

Table 1. Wastes Generated, Treated and Downhole Disposed or Discharged to the Gulf of 

Mexico (Discharges Per Well Unless Otherwise Noted)

Projected Generated Waste Projected Ocean Discharges 

Type of Waste and 

Composition 

Composition Projected 

Amount 

Discharge Rate Discharge Method 

Water-Based 

Drilling Fluid 

Barite, 

additives 

36000 bbls 36000 bbls Discharged at Seafloor 

Synthetic-based 

Drilling fluid 

Esters, 

polyalpha 

olefins 

3000 bbls 3000 bbls NA 

Cuttings Wetted 

with Syntheticbased Fluid 

Esters, 

polyalpha 

olefins 

7700 bbls 7700 bbls Cleaned and Shunted 

Overboard 

Cuttings Wetted 

with Water-based 

Fluid 

Barite, 

additives 

5000 bbls 5000 bbls Discharged at Seafloor 

Cuttings Wetted 

with Oil- based Fluid 

Diesel 0 NA 

Domestic Waste Grey water 450,000 

gal. 

35 

gal/person/day 

Treated and Discharged 

Overboard 

Sanitary Waste Treated 

Sanitary 

Waste 

321,000 

gal. 

25 

gal/day/person 

“ “ 

Deck Drainage Rain/Wash 

Water 

0-100,000 

bbls 

dependent 

on rainfall 

NA “ “ 

Well Treatment, 

Workover or 

Completion Fluids 

NA NA Discharged Overboard 

Desalinization unit Brine 110 

bbls/day 

NA “ “ 

BOP fluid BOP Fluid 35 bbls/yr NA Discharged at seafloor 

Ballast Water NA NA Discharged Overboard 

Bilge water NA NA “ “ 

Excess cement at 

seafloor 

Cement 550 bbls NA Discharged at seafloor 

Fire water NA NA Discharged Overboard 

Cooling water NA NA “ “ 

Produced Water NA NA “ “ 

NA=Not Applicable 
Woodside Energy (USA) Inc. 14 Green Canyon Block 451 

Initial EP 

Revised 1-6-2011 Lease OCS-G 32509 

Table 2. Wastes Transported and/or Disposed of Onshore (Discharges Per Well Unless 

Otherwise Noted)

Projected Generated 

Waste 

Solid and 

Liquid Wastes 

Transportation

Waste Disposal 

Type of 

Waste 

Composition Transport 

Method 

Name/Location 

of Facility 

Amount Disposal 

Method 

Oil-Based 

Fluid 

NA 

Syntheticbased 

Fluid 

Used SBF 

and additives 

Cuttings boxes 

on supply boat 

US Liquids, 

Fouchon, LA 

31000

bbls 

Recycled 

Cuttings 

Wetted 

with OilBased 

Mud 

NA 

Produced 

Sand 

NA 

Trash and 

Debris 

Steel, cables, 

paper, 

cardboard, 

plastic 

Storage bins on 

supply boat 

Waste 

Management 

Galliano, LA 

23.3 cu. 

meter/year 

Landfill 

Used Oil Used oil Drums on 

supply boat 

New Park 

Fourchon, LA 

17 bbls/ 

mo. 

Disposal 

Wash 

Water 

NA 

Chemical 

Wastes 

Chemical 

Waste Solids 

Containers on 

supply boat 

New Park 

Fourchon, LA 

90 bbls/ 

mo. 

Disposal per 

Classification

NA=Not Applicable 

(c) Modeling Report

Not required by EPA under the OCS General Permit. 

(d) NPDES Permits

This information is not required for the activities proposed in this plan in the MMS GOMR. 

(e) Cooling Water Intakes

This information is not required for the activities proposed in this plan in the MMS GOMR. 
AIR EMISSIONS INFORMATION

(a) Screening Checklist

Included in this section, (if applicable) is the Projected Air Emissions Worksheet 

prepared in accordance with NTL No. 2006-G15. 

For this plan, there are no existing facilities or activities co-located with the current 

proposed activities; therefore, the Complex Total Emissions are the same as the Plan 

Emissions. 

Air Quality Screening Questions Yes No 

Is any calculated Complex Total (CT) Emission amount (tons) 

associated with your proposed exploration activities more than 

90% of the amounts calculated using the following formulas: CT 

= 3400D2/3 for CO, and CT = 33.3D for the other air pollutants 

where D = distance to shore in miles)? 

X 

Do your emission calculations include any emission reduction 

measures or modified emission factors? 

X 

Are your proposed exploration activities located east of 87.5° W 

longitude? 

X 

Do you expect to encounter H2S at concentrations greater than 

20 parts per million ppm)? 

X 

Do you propose to flare or vent natural gas for more than 48 

continuous hours from any proposed well? 

X 

Do you propose to burn produced hydrocarbon liquids? X 

The following information was prepared by: 

 Debra Benoit 

 Woodside Energy (USA) 

 Phone: 713-401-0083 

 Email: debra.benoit@woodsideenergy.com

(a) Summary Table of Emissions

COMPANY AREA BLOCK LEASE PLATFORM WELL 

Woodside Energy 

USA Green Canyon 451 G32509 NA Locations A,B,C, 

(GC-451) 

 Emitted Substance 

Year 

 

 PM SOx NOx VOC CO 

2012 49.76 228.27 1710.45 51.31 373.19 

Allowable 3,629.70 3,629.70 3,629.70 3,629.70 77,582.41 

 (c) Spreadsheets

Not required for this submittal. 
Woodside Energy (USA) Inc. 16 Green Canyon Block 451 

Initial EP 

Revised 1-6-2011 Lease OCS-G 32509 

OIL SPILL INFORMATION

(a) Oil Spill Response Planning

 (1) Site-Specific OSRP

 Lease OCS-G 32509 is not located in the Eastern Gulf of Mexico 

 therefore a site-specific OSRP is not required. 

 (2)(i) Regional or Subregional OSRP Information

Woodside’s Regional Oil Spill Response Plan (OSRP) (BOEMRE Operator No. 02407) 

has been revised and submitted for approval on May 19, 2011. The Regional OSRP will 

cover activities proposed in this Plan. OSRP Certification is detailed in Attachment N. 

 (ii) Spill Response Sites 

Primary Response Equipment Location Preplanned Staging Location(s) 

Lake Charles and Fourchon, LA Fourchon, LA 

 (iii) OSRO Information

 Woodside’s primary response providers, Clean Gulf Associates (CGA), National 

Response Corporation (NRC) Helix Well Containment Group (HWCG) and O’Brien’s 

Response Management (ORM), will provide closest available personnel and equipment, 

as well as supervisory personnel. OSRP Certification was accepted May 21, 2011.

(iv) Worst Case Scenario Determination

Category Regional OSRP EP

Type of Activity Exploratory Drilling Exploratory Drilling 

Facility Location (area/block) AT 187 GC 451

Facility Designation2 Wellbore Wellbore

Distance to Nearest Shoreline (miles) 79 109

Volume3

Storage tanks (total) 

Flowlines (on facility) 

Lease term pipelines 

Uncontrolled blowout (volume per 

day)

Total Volume

NA

NA

NA

199,028 bbls

199,028 bbls

NA

NA

NA

159,951 bbls

159,951 bbls

Type of Oil(s) (crude oil, condensate, 

diesel)

Crude Oil Crude Oil 

API Gravity(s)4 28o 29o
Woodside Energy (USA) Inc. 17 Green Canyon Block 451 

Initial EP 

Revised 1-6-2011 Lease OCS-G 32509 

1 Types of activities include pipeline, platform, caisson, subsea completion or manifold, and mobile drilling rig. 2 E.g., Well No. 2, Platform JA, Pipeline Segment No. 6373. 3

 Take your regional OSRP worst-case scenario volume from the appropriate section of your regional OSRP. For EP’s, the 

worst-case scenario volume is the daily volume possible from an uncontrolled blowout. Determine this volume using the 

provisions of 30 CFR 254.47(b). For DOCD’s, determine the volume of your worst-case scenario using the provisions of 30 

CFR 254.47(a), (b), and (c), as appropriate. 4

 Provide API gravity of all oils given under “Type of Oil(s)” above. Estimate for EP’s. 

Since Woodside has the ability to respond to the appropriate worst-case spill scenario included 

in its regional OSRP submitted May 19, 2011 and since the worst-case scenario determined for 

this Plan does not replace the worst-case scenario in our regional OSRP, I hereby certify that 

Woodside has the capability to respond, to the maximum extent practicable, to a worst-case 

discharge, or a substantial threat of such a discharge, resulting from the activities proposed in 

this Plan 

(b) Oil Spill Response Discussion

The oil spill response discussion for the proposed operations are detailed in Attachment “N”.

(c) Modeling Report

Not required for the location of the activities proposed in this plan. 
Woodside Energy (USA) Inc. 18 Green Canyon Block 451 

Initial EP 

Revised 1-6-2011 Lease OCS-G 32509 

ENVIRONMENTAL MONITORING INFORMATION

(a) Monitoring Systems

Woodside is aware of the requirements of NTL No. 2009-G02 whereby MMS established and 

implemented a program to monitor ocean currents and require operators to share the data for all 

floating MODU’s and production facilities operating or installed in water depths greater than 400 

meters (1,312 feet). Woodside will report ocean current data to the National Data Buoy Center 

(NDBC) Internet website as required. 

(b) Incidental Takes 

Woodside does not anticipate the incidental taking of any these species as a result of the 

activities proposed in this Plan based on the implementation of, and adherence to, NTL No. 

2007-G02 “Implementation of Seismic Survey Mitigation Measures and Protected Species 

Observer Program, NTL No. 2007-G03 “Marine Trash and Debris Awareness Training and 

Elimination” and NTL No. 2007-G04 “Vessel Strike Avoidance and Injured/Dead Protected 

Species Reporting”. 

(b) Flower Garden Banks National Marine Sanctuary

Woodside’s activities under this Initial EP are not located within the Protective Zones of the 

Flower Garden Banks or Stetson Bank and therefore are not required to monitor the impacts of 

an oil spill. 
Woodside Energy (USA) Inc. 19 Green Canyon Block 451 

Initial EP 

Revised 1-6-2011 Lease OCS-G 32509 

LEASE STIPULATIONS INFORMATION

Oil and gas exploration and development activities on the OCS are subject to stipulations 

developed before the lease sale and would be attached to the lease instrument, as necessary, 

in the form of mitigating measures. The MMS is responsible for ensuring full compliance with 

stipulations. 

Minerals Management Service’s Stipulation No. 3 does not apply to Green Canyon Block 451, 

this block is not located in any of the Military Warning Areas. 

Stipulation No. 3 – Military Areas This stipulation will be included only in the leases 

located within the Warning Areas and Eglin Water Test Areas 1 and 3. 

Minerals Management Service invoked Stipulation No. 6 for Lease OCS-G 32509, Green 

Canyon Block 451. 

Stipulation No. 6 – Protected Species was invoked to reduce the potential taking of 

Federally protected species (e.g., sea turtles, marine mammals, Gulf sturgeon, and other 

listed species). 

The Minerals Management Service issued NTL 2007-G04 and NTL 2007-G02 pursuant 

to 30 CFR 250.103, 250.23(o) and 250.204(s) to explain how Operators must implement 

measures to minimize the risk of vessel strikes to protected species and report 

observations of injured or dead protected species effective February 7, 2007. Woodside 

will ensure that our contract vessel operators are aware of their requirement to report 

sightings of any injured or dead protected species immediately to the MMS Protected 

Species Biologist by telephone. 

The Minerals Management Service issued NTL 2007-G03 pursuant to 30 CFR 150.103 

to provide guidance and assist the operators in preventing intentional and / or accidental 

introduction of trash and debris into the marine environment. With this assistance and 

with laws such as MARPOL-Annex V, the Marine Plastic Pollution Research and Control 

Act, and regulations imposed by various agencies including the U.S. Coast Guard and 

the U.S. Environmental Protection Agency, our employees will ensure that all offshore 

personnel, including contractors and other support services-related personnel have 

complete understanding of the requirement that Operators be proactive in avoiding 

accidental loss of solid waste items on the OCS. 

Environmental Mitigation Measures Information

(a) Monitoring Systems. 

Woodside does not have existing or planned monitoring systems that are measuring, or 

will measure, environmental conditions and/or will provide project-specific data or 

information on the impacts of these proposed activities. 

(b) Incidental Takes 

Woodside does not anticipate the incidental taking of any these species as a result of 

the activities proposed in this Plan based on the implementation of, and adherence to, 

NTL No. 2007-G02 “Implementation of Seismic Survey Mitigation Measures and 
Woodside Energy (USA) Inc. 20 Green Canyon Block 451 

Initial EP 

Revised 1-6-2011 Lease OCS-G 32509 

Protected Species Observer Program, NTL No. 2007-G03 “Marine Trash and Debris 

Awareness Training and Elimination” and NTL No. 2007-G04 “Vessel Strike Avoidance 

and Injured/Dead Protected Species Reporting”. 
Woodside Energy (USA) Inc. 21 Green Canyon Block 451 

Initial EP 

Revised 1-6-2011 Lease OCS-G 32509 

Decommissioning Information

This information is not required for plans submitted in the MMS GOMR. 
RELATED FACILITIES AND OPERATIONS INFORMATION

(a) Related OCS Facilities and Operations

 This discussion is not required for EP’s. 

(b) Transportation System

 This discussion is not required for EP’s. 

(c) Produced Liquid Hydrocarbons Transportation Vessels

There will be no produced liquid hydrocarbons, including well test fluids, 

transported by means other than a pipeline for the activities proposed in this 

plan. 

SUPPORT VESSELS AND AIRCRAFT INFORMATION

(a) General

The following list provides information regarding the vessels and aircraft Woodside will 

use to support our proposed activities. 

Type of Vessel Maximum Fuel Tank 

Storage Capacity 

Maximum No. in 

Area at Any Time 

Trip Frequency or 

Duration 

Tug boat(s) N/A N/A N/A 

Supply boat(s) 250,000 gals 2 6 times / week 

Anchor boat(s) NA NA NA 

Crew boat(s) 34,000 gals 1 3 times / week 

Helicopter 280 gals 1 3 times / week 

(b) Diesel Oil Supply Vessels

Woodside does not propose to utilize vessels that will transfer diesel oil for purposes 

other than fuel (e.g., base for corrosion control fluids). Florida is not an affected state; 

no activities are proposed within Protective Zones; no surface facility is planned in water 

depths greater than 400 meters; this is not a DOCD for which Alabama is an affected 

state nor a DOCD proposing new multiwell structures for which Louisiana is an affected 

state. 

Size of Fuel 

Supply vessel 

Capacity of fuel 

supply vessel 

Frequency of fuel 

transfers 

Route fuel supply 

vessel will take 

285’ 203,000 gal Weekly Fourchon to MODU 
(c) Drilling Fluids Transportation

Type of Material 

Quantity Being 

Transported 

Quantity Being 

Transported

Transportation Method 

Dry Bulk (Cement, 

Barite, Gel) 

12,000 sx max combined Below deck dry bulk tanks 

onboard OSV 

Synthetic-base drilling 

fluids 

11,000 bbls max per 

voyage 

Below deck liquid mud 

tanks onboard OSV 

Water Based drilling 

fluids 

12,000 bbls max per 

voyage 

Below deck liquid mud 

tanks onboard OSV 

(d) Solid and Liquid Wastes Transportation

See Table 2 of Waste and Discharge Section. 

(e) Vicinity Map

A Vicinity Plat showing the location of Green Canyon Block 451 relative to the shoreline 

and the onshore base is included as Attachment J. 
Woodside Energy (USA) Inc. 24 Green Canyon Block 451 

Initial EP 

Revised 1-6-2011 Lease OCS-G 32509 

ONSHORE SUPPORT FACILITIES INFORMATION

(a) General

Woodside proposes to utilize the following existing onshore base for support: 

Name Location Existing, New or 

Modified 

C-Port Fourchon, LA Existing 

(b) Support Base Construction or Expansion

The proposed operations do not mandate any immediate measures for land acquisition or 

expansion of the existing onshore base facilities. 

(c) Support Base Construction or Expansion Timetable

No known shorebase construction is planned for the time period of this operation. 

(d) Waste Disposal

See Table 2 of Waste and Discharge Section. 

(e) Air Emissions

This discussion is not required to accompany EP’s submitted in the MMS GOMR. 

(f) Unusual Solid and Liquid Wastes

This discussion is not required to accompany EP’s submitted in the MMS GOMR. 
Woodside Energy (USA) Inc. 25 Green Canyon Block 451 

Initial EP 

Revised 1-6-2011 Lease OCS-G 32509 

SULPHUR OPERATIONS INFORMATION

Woodside is not proposing to conduct sulphur operations in this plan. 
Woodside Energy (USA) Inc. 26 Green Canyon Block 451 

Initial EP 

Revised 1-6-2011 Lease OCS-G 32509 

Coastal Zone Management Act (CZMA) Information

The States of Texas, Louisiana, Mississippi, Alabama, and Florida have federally approved 

coastal zone management programs (CZMP). Applicants for an OCS plan submitted to the 

Minerals Management Service must provide a certification with necessary data and information 

for the affected State to determine that the proposed activity(s) complies with the enforceable 

policies of each States’ approved program, and that such activity will be conducted in a manner 

consistent with the program. 

(a) Consistency Certification

A Coastal Zone Management Consistency Certification for the State of Louisiana is required for 

the initial exploratory activities proposed in this plan and is included in Attachment K. 

(b) Alabama Enforceable Polices

Not required for this plan. 

(c) Other Information

The enforceable policies for the State of Louisiana were considered in making our certification 

of consistency above.
Woodside Energy (USA) Inc. 27 Green Canyon Block 451 

Initial EP 

Revised 1-6-2011 Lease OCS-G 32509 

ENVIRONMENTAL IMPACT ANALYSIS (EIA)

The Environmental Impact Analysis is included as Attachment M.
Woodside Energy (USA) Inc. 28 Green Canyon Block 451 

Initial EP 

Revised 1-6-2011 Lease OCS-G 32509 

(i) References

Administrative Information 

NTL 2010-N10 Statement of Compliance with Applicable Regulations and Evaluation of 

Information Demonstrating Adequate Spill Response and Well Containment Resources 

NTL 2010- N06 Information Requirements for EPs, DPPs, and DOCDs on the OCS. 

3D GeoHazard Study of Block 325, Walker Ridge Area, OCS-G 32673 prepared for Woodside. 

NTL 2009-G40 Benthic Communities 

NTL 2009-G39 Biologically Sensitive Underwater Features & Areas 

NTL 2009-G27 Submitting Exploration Plans & Development Operations Coordination 

Documents 

NTL 2009-G06 Military Warning and Water Test Areas. 

NTL 2009-G02 Ocean Current Monitoring 

NTL 2008-G20 Revisions to the List of OCS Lease Blocks Requiring Archaeological Resource 

Surveys and Reports. 

NTL 2008-N07 Supplemental Bond Procedures. 

NTL 2008-N05 Guidelines for Oil Spill Financial Responsibility (OSFR) for Covered Facilities. 

NTL 2008-G06 Remotely Operated Vehicle Surveys in Deepwater. 

NTL 2008-G04 Information Requirements for Exploration Plans and Development Operations 

Coordination Documents. 

NTL 2007-G04 Vessel Strike Avoidance and Injured/Dead Protected Species Reporting. 

NTL 2007-G03 Marine Trash and Debris Awareness and Elimination. 

NTL 2007-G02 Implementation of Seismic Survey Mitigation Measures and Protected Species 

Observer Program

NTL 2005-G07 Archaeological Resource Surveys and Reports. 

NTL 2001-G10 Clarification of Eastern Gulf of Mexico Sale 181 Military Areas Stipulation. 

NTL 2000-G16 Guidelines for General Lease Surety Bonds. 

Current Code of Federal Regulations 30 Parts 250, 254 and 256. 
Woodside Energy (USA) Inc. 29 Green Canyon Block 451 

Initial EP 

Revised 1-6-2011 Lease OCS-G 32509 

ADMINISTRATIVE INFORMATION

(a) Exempted Information Description (Public Information Copies Only)

In accordance with 43 CFR Part 2, Appendix E, sections (4) and (9), the following information is 

exempt from disclosure and has been omitted from the Public Information copy of this plan: 

• The geologic objectives, BHL, TVD, and MD information on form MMS-137 (OCS Plan 

Information Form) in Attachment A 

• All items under Geological and Geophysical Information, except for the non-proprietary 

version of shallow hazards assessment 

• Correlative well information used to justify H2S classification request under Hydrogen 

Sulfide Information 

(b) Bibliography

3D GeoHazard Study of Block 451, Green Canyon Area, OCS-G 32509, prepared for Woodside 

by C&C in July 2009. 
Attachment A 

Plan Information 
APPENDIX A - OCS PLAN INFORMATION FORM 

General Information 

Type of OCS X Exploration Plan (EP) Development Operations Coordination Document (DOCD) 

Company Name: Woodside Energy MMS Operator Number: 02407 

Contact Person: Debra K. Benoit 

Phone Number: 713-401-0083 

Address: 

5151 San Felipe Street Suite 1200 

Houston, Texas 77056 E-Mail Address: debra.benoit@woodsideenergy.com

Lease:OCS-G-32509 Area: GC Block: 451 Project Name (If Applicable): Floyd 

Objective(s): X Oil Gas Sulfur Salt Onshore Base: Fourchon, LA Dist. to Closest Land 109 mi

Description of Proposed Activities (Mark all that apply) 

X Exploration drilling Development drilling 

Well completion Installation of production platform 

Well test flaring Installation of production facilities 

Installation of well protection structure Installation of satellite structure 

Installation of subsea wellheads and/or manifolds Installation of lease term (ROW) pipelines 

X Temporary well abandonment Commence production 

Other (Specify and describe) 

Have you submitted or do you plan to submit a Conservation Information Document to Yes X No 

Do you propose to use new or unusual technology to conduct your activities? Yes X No 

Do you propose any facility that will serve as a host facility for deepwater subsea Yes X No 

Do you propose any activities that may disturb an MMS-designated high-probability Yes X No 

Have all the surface locations of your proposed activities been previously reviewed and Yes X No 

Tentative Schedule of Proposed Activities 

Proposed Activity Start Date End Date No. of days 

Drill & TA #A 4/14/2012 7/15/2012 93

Drill & TA #B 4/14/2013 7/15/2013 93

Drill & TA #C 4/14/2014 7/15/2014 93

Description of Drilling Rig Description of Production Platform

Jackup Drillship Caisson Tension leg platform 

Gorilla Jackup Platform rig Well protector Compliant tower 

Semisubmersible Submersible Fixed platform Guyed tower 

X DP Semisubmersible Other (Attach Description) Subsea manifold Floating production 

Drilling Rig Name (If Known): Maersk Developer Spar Other (Attach 

Description of Lease Term Pipelines 

From (Facility/Area/Block) To (Facility/Area/Block) Diameter(In) Length Product

MMS Form MMS-137 Page 1 of 4
OCS PLAN INFORMATION FORM (CONTINUED) 

Include one copy of this page for each proposed well / structure 

Proposed Well/Structure Location 

Well or Structure Name/Number: Location A Subsea Completion 

Anchor Radius (if applicable) in feet: N/A X Yes No 

Surface Location Bottom-Hole Location (For Wells) 

Lease No. OCS-G 32509 OCS-G 32509 

Area Name Green Canyon Green Canyon 

Block No. 451 451 

Block line 

Departures 

(in feet)

N/S Departure: 5,492’ FNL N/S Departure: 

 E/W Departure: 4,472’ FWL E/W Departure: 

Lambert X-Y 

coordinates 

X: 2,158,712’ X: 

 Y: 9,989,548’ Y: 

Latitude/ 

Longitude

Latitude: 27° 31’ 10.007” N Latitude: 

NAD 27 Longitude: 91° 24’ 01.694” W Longitude: 

TVD (Feet): MD (Feet): Water Depth (Feet): 3,066 

Anchor Locations for Drilling Rig or Construction Barge 

Anchor Name or No. Area Block X Coordinate Y Coordinate Length of Anchor 

Chain on Seafloor 

Paperwork Reduction Act of 1995 Statement: The Paperwork Reduction Act of 1995 (44 U.S.C. Chapter 35) requires us to inform you that MMS 

collects this information as part of an applicant’s Exploration Plan or Development Operations Coordination Document submitted for MMS approval. We 

use the information to facilitate our review and data entry for OCS plans. We will protect proprietary data according to the Freedom of Information Act 

and 30 CFR 250.196. An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a 

currently valid Office of Management and Budget Control Number. The use of this form is voluntary. The public reporting burden for this form is 

included in the burden for preparing Exploration Plans and Development Operations Coordination Documents. We estimate that burden to average 600 

per response, or 640 with an accompanying EP, or 690 with an accompanying DPP or DOCD, including the time for reviewing instructions, gathering 

and maintaining data, and completing and reviewing the forms associated with subpart B. Direct comments regarding the burden estimate or any other 

aspect of this form to the Information Collection Clearance Officer, Mail Stop 4230, Minerals Management Service, 1849 C Street, N.W., Washington, 

DC 20240

MMS Form MMS-137 (July 2005 – Supersedes all previous editions of form MMS-137 which may not be used.) Page 2 of 4

PUBLIC INFORMATION COPY 
OCS PLAN INFORMATION FORM (CONTINUED) 

Include one copy of this page for each proposed well / structure 

Proposed Well/Structure Location 

Well or Structure Name/Number: Location B Subsea Completion 

Anchor Radius (if applicable) in feet: X Yes No 

Surface Location Bottom-Hole Location (For Wells) 

Lease No. OCS-G 32509 OCS-G 32509 

Area Name Green Canyon Green Canyon 

Block No. 451 451 

Block line 

Departures 

(in feet)

N/S Departure: 7,492’ FNL N/S Departure: 

 E/W Departure: 4,472’ FWL E/W Departure: 

Lambert X-Y 

coordinates 

X: 2,158,712’ X: 

 Y: 9,987,548’ Y: 

Latitude/ 

Longitude

Latitude: 27° 30’ 50.203” N Latitude: 

NAD 27 Longitude: 91° 24’ 01.981” W Longitude: 

TVD (Feet): MD (Feet): Water Depth (Feet): 3,212 

Anchor Locations for Drilling Rig or Construction Barge 

Anchor Name or No. Area Block X Coordinate Y Coordinate Length of Anchor 

Chain on Seafloor 

Paperwork Reduction Act of 1995 Statement: The Paperwork Reduction Act of 1995 (44 U.S.C. Chapter 35) requires us to inform you that MMS 

collects this information as part of an applicant’s Exploration Plan or Development Operations Coordination Document submitted for MMS approval. We 

use the information to facilitate our review and data entry for OCS plans. We will protect proprietary data according to the Freedom of Information Act 

and 30 CFR 250.196. An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a 

currently valid Office of Management and Budget Control Number. The use of this form is voluntary. The public reporting burden for this form is 

included in the burden for preparing Exploration Plans and Development Operations Coordination Documents. We estimate that burden to average 600 

per response, or 640 with an accompanying EP, or 690 with an accompanying DPP or DOCD, including the time for reviewing instructions, gathering 

and maintaining data, and completing and reviewing the forms associated with subpart B. Direct comments regarding the burden estimate or any other 

aspect of this form to the Information Collection Clearance Officer, Mail Stop 4230, Minerals Management Service, 1849 C Street, N.W., Washington, 

DC 20240

MMS Form MMS-137 (July 2005 – Supersedes all previous editions of form MMS-137 which may not be used.) Page 3 of 4

PUBLIC INFORMATION COPY 
OCS PLAN INFORMATION FORM (CONTINUED) 

Include one copy of this page for each proposed well / structure 

Proposed Well/Structure Location 

Well or Structure Name/Number: Location C Subsea Completion 

Anchor Radius (if applicable) in feet: X Yes No 

Surface Location Bottom-Hole Location (For Wells) 

Lease No. OCS-G 32509 OCS-G 32509 

Area Name Green Canyon Green Canyon 

Block No. 451 451 

Block line 

Departures 

(in feet)

N/S Departure: 4,468’ FNL N/S Departure: 

 E/W Departure: 4,872’ FWL E/W Departure: 

Lambert X-Y 

coordinates 

X: 2,159,112’ X: 

 Y: 9,990,572’ Y: 

Latitude/ 

Longitude

Latitude: 27° 31’ 20.097” N Latitude: 

NAD 27 Longitude: 91° 23’ 57.105” W Longitude: 

TVD (Feet): MD (Feet): Water Depth (Feet): 3,038 

Anchor Locations for Drilling Rig or Construction Barge 

Anchor Name or No. Area Block X Coordinate Y Coordinate Length of Anchor 

Chain on Seafloor 

Paperwork Reduction Act of 1995 Statement: The Paperwork Reduction Act of 1995 (44 U.S.C. Chapter 35) requires us to inform you that MMS 

collects this information as part of an applicant’s Exploration Plan or Development Operations Coordination Document submitted for MMS approval. We 

use the information to facilitate our review and data entry for OCS plans. We will protect proprietary data according to the Freedom of Information Act 

and 30 CFR 250.196. An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a 

currently valid Office of Management and Budget Control Number. The use of this form is voluntary. The public reporting burden for this form is 

included in the burden for preparing Exploration Plans and Development Operations Coordination Documents. We estimate that burden to average 600 

per response, or 640 with an accompanying EP, or 690 with an accompanying DPP or DOCD, including the time for reviewing instructions, gathering 

and maintaining data, and completing and reviewing the forms associated with subpart B. Direct comments regarding the burden estimate or any other 

aspect of this form to the Information Collection Clearance Officer, Mail Stop 4230, Minerals Management Service, 1849 C Street, N.W., Washington, 

DC 20240

MMS Form MMS-137 (July 2005 – Supersedes all previous editions of form MMS-137 which may not be used.) Page 4 of 4

PUBLIC INFORMATION COPY 
Attachment B 

Well Location Map 

Attachment C 

Bathymetry Map 
OCS-G-25144

CHEVRON

OCS-G-25145

KERR-MCGEE

OCS-G-25155

MURPHY

OCS-G-25156

MURPHY

OCS-G-28081

WOODSIDE

OCS-G-25143

MAXUS

OCS-G-25149

MAXUS

OCS-G-28078

WOODSIDE OCS-G-32509

WOODSIDE

GC408

GC494 GC495 GC496

GC406 GC407

GC452

GC450

GC451

2,000'

2,000'

2,000'

SITE CLEARANCE

COLOR-SHADED BATHYMETRY MAP

"FLOYD" PROSPECT

WELLS "A", "B", & "C" LOCATIONS

OCS-G-32509

BLOCK 451

GREEN CANYON AREA

Bathymetric contours (in feet)

CGG survey inline number (Inline spacing = 65.62 feet)

CGG survey crossline number (Crossline spacing = 82.02 feet)

Bathymetry data processed with C & C Hydromap© software from 3D

dataset.

Contour interval = 10 feet

Bin size = 25 meters (82.02 feet)

Zero datum = Mean Sea Level

Applied acoustic velocity = Advocate and Hood (1993) for data between

sea level and seafloor.

Color shaded image

Sun azimuth = 45°

Sun elevation = 30°

Depth in feet

 -3000

 -3010

 -3020

 -3030

 -3040

 -3050

 -3060

 -3070

 -3080

 -3090

 -3100

 -3110

 -3120

 -3130

 -3140

 -3150

 -3160

 -3170

 -3180

 -3190

 -3200

 -3210

 -3220

 -3230

 -3240

 -3250

 -3260

 -3270

 -3280

 -3290

 -3300

 -3310

 -3320

 -3330

 -3340

 -3350

 -3360

 -3370

 3380

 3390

 3400

 3410

 3420

 3430

 3440

 3450

 3460

 3470

 3480

 3490

 3500

 3510

 3520

 3530

 3540

 3550

 3560

 3570

 3580

 3590

 3600

 3610

 3620

 3630

 3640

 3650

 3660

 3670

 3680

 3690

 3700

 3710

 3720

 3730

 3740

 3750
Attachment D 

Time vs Depth 

Tables
Attachment E 

Structure Map 
Attachment F 

3-D Seismic 
Attachment G 

Structure

Cross-Section
Attachment H 

Site Clearance 

Letters
______________________________________________________________________________ 

_____________________________________________________________________________________________________________________ 

730 EAST KALISTE SALOOM ROAD, LAFAYETTE, LOUISIANA 70508 

1

January 12, 2011 

Woodside Energy Ltd. 

830 West Causeway Approach, Suite 1000 

Mandeville, LA 70471 

Attn: Mr. Doug Lumpkin 

Site Clearance Letter 

Proposed Well “A” 

Block 451 (OCS-G-32509), Green Canyon Area 

INTRODUCTION 

Woodside Energy Ltd. (Woodside) contracted C & C Technologies, Inc. (C & C) to prepare a well site 

clearance letter for the drilling location of the proposed Well “A” in Block 451 (OCS-G-32509), Green 

Canyon (GC) Area. The data used for the site clearance letter is an exploration-quality 3D seismic 

volume, collected by CGG Veritas between 1999 and 2000, provided by Woodside. C & C completed the 

geohazard report titled “Shallow Hazard Report, “Floyd” Prospect, Block 451 (OCS-G-32509), Green 

Canyon Area” in July 2009. This site clearance letter is based on findings provided within this report. 

This letter provides a tophole drilling prognosis and addresses seafloor conditions within a 2,000-foot 

radius of the proposed well location. The depth limit of the interpretation is approximately two and a half 

seconds of two-way traveltime below the seafloor. A dynamically positioned drilling rig is planned to 

drill the well, therefore an anchor assessment is not needed. The assessment and enclosures presented 

with this letter comply with Bureau of Ocean Energy Management, Regulation and Enforcement 

(BOEMRE) guidelines provided in Notice To Lessees (NTL) No. 2008-G05 (Shallow Hazards Program) 

and NTL No. 2000-G20 (Deepwater Chemosynthetic Communities). Per Woodside’s request, on January 

10, 2011, this letter and supporting maps have been updated to meet the requirements as stated in new the 

NTL No. 2009-G40 (Deepwater Benthic Communities) 

METHODS 

The 3D seismic data used for this site clearance assessment were provided in SEG-Y format on a digital 

linear tape (DLT) tape, where the files were retrieved and saved on a secure server then processed for shallow 

hazards by C & C. The data were loaded into Seismic Micro Technology’s (SMT) Kingdom Suite 2D/3D 

Pak, Version 8.3 for interpretation. The time-migrated data volume was processed at a two-millisecond 

sample rate and was interpreted to two and a half seconds below sea level. The inlines of the CGG Veritas 

data set run west-east and are spaced at 65.62-foot (20-meter) intervals. The crosslines run north-south and 

are spaced at 82.02-foot (25-meter) intervals. 

A strong positive amplitude peak, flanked by troughs, represents the seafloor on the seismic volumes. 

Amplitude values are represented by IBM 32-bit floating-point numbers, identified during data loading. 

The data provided were adequate for regional screening of the seafloor and shallow geologic conditions. 

WELL LOCATION 

The coordinates and calls of the proposed surface location for GC451 Well “A” are tabulated below: 
______________________________________________________________________________ 

_____________________________________________________________________________________________________________________ 

730 EAST KALISTE SALOOM ROAD, LAFAYETTE, LOUISIANA 70508 

2

Well Coordinates 

X-Coordinate Y-Coordinate 

Latitude Longitude Calls From Block 451 

Green Canyon Area 

Well “A” 2,158,712.00’ 9,989,548.00’ 27°31’10.007” N 91°24’01.694” W FNL 5,492’ FWL 4,472’ 

The geodetic datum used for this project is the North American Datum of 1927 (NAD27) on the Clarke 1866 

Ellipsoid. The datum is projected using the Universal Transverse Mercator (UTM) Zone 15 North (15N). 

All grid units, including scales and measurements, are in U.S. Survey Feet. The surface hole location of the 

proposed GC451 Well “A” and the 2,000-foot radius are displayed on the Color-Shaded Bathymetry Map 

(Sheet 1), Seafloor Amplitude Map (Sheet 2), Seafloor Features Map (Sheet 3), and the Subsurface Features 

Map (Sheet 4). 

REGIONAL GEOLOGY 

The “Floyd” Prospect is located in the west-central Gulf of Mexico in an area designated as the Green 

Canyon Area by the BOEMRE. The study area lies on the upper to middle continental slope of offshore 

Louisiana. This area of the slope consists of diapiric highs and basin-like topography. Two types of 

depositional sequences are identified in the region, condensed and expanded sections. Condensed 

sections are deposited during high sea level stands and consist of slowly accumulated hemipelagic clays. 

The expanded sections are formed during low sea level stands and consist of rapidly accumulated, coarsegrained clastic deposits (sands and gravels) of variable thickness. 

The area where the well is planned is undergoing regional extension and localized compression where 

allochthonous salt movement is the primary influence on the seafloor and subsurface sediments. Salt 

within this area is shallow and located at a depth of approximately 1,110 to 2,400 feet below the seafloor. 

The underlying salt sheet is migrating toward the southeast and has formed the Timbalier Basin to the 

southeast of the proposed well location. 

BATHYMETRY AND SEAFLOOR GRADIENTS 

The water depth at the proposed GC451 Well “A” surface location is 3,066 feet below sea level (BSL). 

Within the 2,000-foot radius the seabed depth ranges from 3,020 feet BSL in the northeastern portion of 

the 2,000-foot boundary to 3,220 feet BSL at the southern portion of the 2,000-foot boundary in Block 

GC451 (Sheet 1). Water depths in the survey area were determined by applying the 1993 Advocate and 

Hood empirical time-depth model for calculating water depth in the northwest Gulf of Mexico. This 

equation is: D = 0.1105 - 5066.9193T + 468.6693T2

 - 554.7107T3 + 340.7019T4 - 116.9910T5 + 

20.7280T6

 - 1.4658T7, where D = water depth in feet and T = one-way traveltime in seconds. 

The seafloor at the proposed well site is on the southeastern side of an elongated fault block where the 

seafloor slopes to the southeast at an average gradient of 2.5° (Sheet 1; Figure No. 1). Potential seafloor 

hazards identified within the 2,000-foot radius include seafloor faulting with localized gradients not 

exceeding 27°. The well site is proposed between two normal fault scarps striking southwest to northeast. 

The fault scarps are located due north and south at a distance of 405 feet and 608 feet, respectively, of the 

proposed Well “A” location. 

SEAFLOOR HAZARDS 

The seafloor reflector displays a range of low to moderate amplitudes within the 2,000-foot radius. In general 

the seafloor exhibits moderate amplitudes suggesting finely textured seafloor sediments that are likely 

comprised of hemipelagic clay (Sheet 2; Figure No. 2). Areas of low return identified on the fault scarp faces 

are attributed to the high angle of seabed where signal reflection is low. This lower amplitude likely results 
______________________________________________________________________________ 

_____________________________________________________________________________________________________________________ 

730 EAST KALISTE SALOOM ROAD, LAFAYETTE, LOUISIANA 70508 

3

from the seismic signal being deflected away from the hydrophones by the high angle of incidence of the 

fault scarp face. 

At the well location no seafloor hazards are present that might pose a problem for drilling activities. Several 

fault scarps are identified within the 2,000-foot radius with scarps to the north and south, exhibiting 35 and 60 

feet, respectively, of seafloor displacement (Sheet 3). No recent slumping is evident along the fault scarps. 

No other significant seafloor features are located at the proposed Well “A” location that could interfere with 

drilling activities. 

POTENTIAL DEEPWATER BENTHIC COMMUNITIES 

High-amplitude seafloor anomalies are a potential indicator of carbonates and deepwater benthic community 

habitats. The seafloor at the proposed well location, and surrounding 2,000-foot radius, contains no low or 

high positive seafloor amplitudes associated with fluid expulsion or mounded carbonates representing 

potential deepwater benthic communities. 

The nearest reported deepwater benthic community is located in Block 272, Green Canyon Area, 

approximately 13 miles northwest of the proposed Well “A” location according to the BOEMRE (NTL 

No. 2009-G40). While, according to NTL 2009-G40, deepwater benthic communities are not know to 

exist within the planned well area, deepwater benthic communities are known to exist in similar geologic 

conditions to those located north of Well “A”. Mound features with associated expulsion and higher 

amplitudes are evident in the extreme northern portion of Block 451 and southern portion of Block 467, 

outside of the 2,000-foot radius. No areas of potential deepwater benthic communities are identified 

within 2,000 feet of the proposed location (Figure Nos. 3 and 4). 

MAN-MADE HAZARDS 

A review of company and BOEMRE data shows that no pipelines, umbilicals, wells, or platforms are located 

within a 2,000-foot radius of the proposed well location (Sheet 3). Man-made objects are below the 

resolution of 3D seismic data, thus unknown objects may exist at the well site. The drilling location of the 

Well “A” is free from any known man-made hazards and infrastructure. 

SUBSURFACE GEOHAZARDS AND STRATIGRAPHY 

Five stratigraphic units of distinct seismic character were assessed (Sheet 4; Figure Nos. 3 and 4). 

Woodside provided C & C with check shot survey data used to derive the total vertical depth (TVD) in 

feet from the corresponding two-way traveltime in seconds. From these values an equation was derived 

that calculates structure depth below sea level: 

Y = 386.98(x2

) + 1,963.5x 

Where Y = depth below sea level in feet and x = two-way traveltime in seconds. A detailed description of 

the sequence units can be found in the 2009 Shallow Hazard Report, “Floyd” Prospect, Block 451 (OCSG-32509), Green Canyon Area. 

Subsurface deposition in the upper 170 feet, Unit A, occurred during a high sea level stand and is 

considered a “condensed section”. This unit is likely comprised of hemipelagic clays laid down as a 

drape deposit and interbedded layers of fine-grained turbidites, or thin mass transport deposits, and some 

possible sands (Figure Nos. 3 and 4). Unit A is categorized by uniform parallel reflectors, which are 

discontinuous only as a result of faulting from subsurface salt. No slumping or mass transport deposits 

are evident along the downthrown side of faulting within the 2,000-foot radius. 

At the well bore, Unit B contains low to moderate amplitude parallel reflectors at the top of the unit which 

become deformed with depth due to faulting (Figure Nos. 3 and 4). The Unit B sequence is identified 170 
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4

to 347 feet below the mudline with slumping and mass transport deposits evident within this unit. This 

unit has the characteristics resembling an “expanded section” associated with a lower sea level stand. 

Some of the reflectors appear to be truncated indicating a possible unconformity associated with changes 

in surface morphology. The seafloor fault located north of the proposed surface location crosses the well 

bore 188 feet below the mudline (1.321 seconds) within this unit. Low amplitude reflectors are 

interpreted to indicate fine-grained silts and clays with mass movement deposits exhibiting higher 

amplitude values suggesting more sand rich sediments. 

Unit C consists of low to high, parallel to chaotic, reflectors with variable acoustic impedance (Figure 

Nos. 3 and 4) and is found 347 to 616 feet below the mudline. The top of Unit C represents an 

unconformity, resulting from eroded uplifted beds. Moderate to high reflectors, of primarily parallel 

orientation, are disrupted by intense faulting. Increased shear strength may occur below Unit C due to the 

unconformity. The higher amplitude values are interpreted to result from sand rich deposits likely 

associated with mass movement deposits. These parallel reflectors indicate varying stratigraphic 

thickness. The lower portion of this unit is comprised of chaotic reflectors with low amplitude values 

likely saturated with fluid from dissolution occurring above the top of salt. 

Unit D is characterized by discontinuous, chaotic reflectors, showing primarily low to moderate 

amplitudes between 616 to 1,813 feet below the mudline. Low amplitude chaotic reflectors are evident in 

the upper portion of the unit (Figure Nos. 3 and 4). The base of Unit D along the well bore is the 

stratigraphic contact with the top of salt due to Horizon 4 being indistinguishable. At a depth of 1,475 

feet BML, moderate to high amplitudes are evident extending to the top of salt. These higher amplitude 

reflectors are contained within a localized depression on the top of salt. The change in seismic character 

within this section could be the possible result of lithological differences as compared to the upper 

section, or a function of salt dissolution/sediment interaction, and likely a combination of both. The well 

bore will pierce the top of salt (1,813 feet below the mudline) in this depression where the higher 

amplitude reflectors are present. The unpredictable nature of salt and its movement increases the risk of 

well bore stability at the salt/sediment interface. 

SHALLOW GAS 

Anomalies of very high amplitude, commonly termed bright spots, are interpreted as potential regions of 

fluid/gas saturation usually associated with porous sands. Shallow gas is interpreted with amplitude 

levels and the gas risk is assessed as being at one of four levels. These are: 

• Negligible - No amplitude anomalies or other gas indicators present. 

• Low risk of gas - Generally indicated by increased amplitude (2-3x background level) 

and phase reversal. This may also include diffuse areas of gas blanking. 

• Moderate risk of gas - Generally indicated by high amplitude (3-4x background level) 

and phase reversal. 

• High risk of gas - Generally indicated by the highest amplitudes (in excess of 4x 

background level), phase reversal, and a combination of other attributes indicative of 

the presence of gas, particularly velocity pull-down and masking of underlying 

sediments. Stratigraphic and structural settings may also be taken into account. 

No high amplitude subsurface amplitude anomalies are noted at the location of the proposed well bore 

(Sheet 4; Figure No. 5). A negligible to moderate risk of shallow gas exists along the well bore for the 

proposed Well “A” drilling site. Due to the subsurface salt being so shallow and extensive throughout the 

region, the only form of structural closures are the fault blocks that have formed, however no high 

amplitudes appear to be associated with these features. 
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SHALLOW WATER FLOW (SWF) 

Shallow Water Flows (SWF) are overpressured unconsolidated sands encountered in the tophole sections 

of some wells drilled in the deepwater areas of the Gulf of Mexico. Sands with SWF potential often lie 

below a seal that prevents dewatering and compaction after deposition. The sands are usually 

unconsolidated and overpressured. The pressure rises with overburden causing a potentially disastrous 

hazard for drilling operations. The nearest reported shallow water flows occurred approximately 24 and 

25 miles northeast and northwest, respectively, of the proposed well site. A moderate severity shallow 

water flow event occurred during ERT’s drilling of GC282 Well No. 1 (OCS-G-16727) at a depth of 

2,121 feet below the mudline. BHP’s GC237 Well No. 3 (OCS-G-15563) encountered a low severity 

shallow water flow at a depth of 720 feet below the mudline. These shallow water flow events occurred 

in the northeastern portion of the Green Canyon Area and are attributed to deposition of the Mississippi 

Fan system. The third closest shallow water flow event occurred at BP’s Well No. 2 (OCS-G-12205) 

recorded as a low severity event 1,354 feet below the mudline in GC181. Well integrity was maintained 

at all three drilling sites. No seismic data was available to correlate the sand prone high SWF potential 

units to the Well “A” location. 

The assessment of seismic profiles suggests the region is highly faulted and stratigraphy is greatly 

impacted by salt induced uplift and migration. No direct indicators of channelized sediments are present 

along the proposed drilling site. However, in complexly faulted structures, formation pressures may be 

compartmentalized and may vary between different fault blocks. Areas with extensive shallow faulting 

are also vulnerable to low-margin drilling conditions. The overall risk of shallow water flow is negligible 

to moderate at the well location. Unit C has the highest potential for a shallow water flow event due to 

the sediments exhibiting characteristics similar to mass transport deposits covered by a rapidly deposited 

sediments. A tophole prognosis chart summarizing subsurface conditions and shallow water flow 

potential is provided as Figure No. 5. 

GAS HYDRATES 

Gas hydrates are in ice crystalline form of gas hydrocarbons in deepwater marine environments where the 

conditions of pressure and temperature are favorable. The hydrate stability zone is the depth interval 

between the seafloor and the point where the hydrate is no longer stable in form. The thermal gradient of 

the seabed soils determines the depth of the hydrate stability zone base. The acoustic impedance contrast 

caused between the hydrate and free gas trapped at the base of the hydrate stability zone forms a Bottom 

Simulating Reflector (BSR) on seismic profiles. This BSR reflector cross cuts the normal seismic 

stratigraphy, much like a bottom multiple. 

The areas where seafloor gas hydrates accumulate in the near-surface sediments of the Gulf of Mexico are 

generally unfavorable sites for drilling operations. Irregular seafloor topography, gas seeps, gas 

chimneys, seafloor hydrates and deepwater benthic communities may all be found in close association. 

There was no indication of any obvious BSRs on the 3D data collected in Block 451, Green Canyon Area. 

SURFACE CONDUCTOR JETTING ASSESSMENT 

The Surface Conductor Jetting Assessment for the upper 120 milliseconds (~300 feet) of the 3D 

exploration seismic data is included as Figure No. 6 (assumed velocity of 5,000 feet/second). The 

interpreted soil lithology from the seismic profiles is presented as part of the assessment. 

The near seafloor seismic stratigraphy at the drill site is characterized by alternating low to moderate 

amplitude reflectors representing primarily Holocene and Late Pleistocene clay beds with possible 

interbedded layers of fine-grained debris flows. A possible unconformity exists approximately 140 feet 

BML at the boundary between Unit A and B. The fault scarp located just north of the well location 
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6

intersects the well bore approximately 188 feet BML, near this boundary. It is recommended to set the 

casing below the faulted zone. 

CONCLUSIONS 

The proposed surface well site location is clear of geological constraints. The seafloor within the 2,000-foot 

radius of the drill location does contain several fault scarps, though none intersect the proposed Well “A” 

surface location. Drilling efforts need to take note of the positions of these features and avoid as necessary. 

The northern fault intersects the well bore at 188 feet below the mudline. 

No high or low seafloor amplitudes, that may indicate the occurrence of hard ground, carbonates, or potential 

expulsion, are found within 2,000 feet of the proposed Well “A” surface location. 

No known infrastructure exists in proximity of the Well “A” location. 

 

A negligible to moderate risk of shallow gas exists along the majority of the well bore for the proposed 

Well “A” drilling site. 

A possible lithological change or a function of salt dissolution/sediment interaction occurs at a depth of 

1,475 to 1,813 feet below the mudline. Caution should be used when drilling through this interval and the 

top of salt due to the unpredictable nature of salt movement, dissolution, and possible pressure 

differences. 

The assessment of seismic profiles suggests all units exhibit a negligible to moderate risk of shallow 

water flow at the well location. 

Thank you for this opportunity to be of service. Please contact us if you have any questions concerning 

this assessment. 

Sincerely yours, 

Hallie Graves 

Marine Geologist 

Enclosures 

Figure No. 1. Seafloor rendering and features identified within 2,000 feet of well location. 

Figure No. 2. 3D volume cut away with seafloor amplitudes overlain. 

Figure No. 3. 3D seismic Inline 2673 through Well “A”. 

Figure No. 4. 3D seismic Crossline 2519 through Well “A”. 

Figure No. 5. Tophole prognosis chart for the proposed Well “A” in Block 451, Green Canyon Area. 

Figure No. 6. Surface Conductor Jetting Assessment for Proposed Well “A”. 

Figure No. 7. Extracted wavelet and power spectrum at Proposed Well “A” in Block 451, Green Canyon 

Area. 

Sheet 1. Color-Shaded Bathymetry Map 

Sheet 2. Seafloor Amplitude Map 
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7

Sheet 3. Seafloor Features Map 

Sheet 4. Subsurface Features Map 
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1

January 12, 2011 

Woodside Energy Ltd. 

830 West Causeway Approach, Suite 1000 

Mandeville, LA 70471 

Attn: Mr. Doug Lumpkin 

Site Clearance Letter 

Proposed Well “B” 

Block 451 (OCS-G-32509), Green Canyon Area 

INTRODUCTION 

Woodside Energy Ltd. (Woodside) contracted C & C Technologies, Inc. (C & C) to prepare a well site 

clearance letter for the drilling location of the proposed Well “B” in Block 451 (OCS-G-32509), Green 

Canyon (GC) Area. The data used for the site clearance letter is an exploration-quality 3D seismic 

volume, collected by CGG Veritas between 1999 and 2000, provided by Woodside. C & C completed the 

geohazard report titled “Shallow Hazard Report, “Floyd” Prospect, Block 451 (OCS-G-32509), Green 

Canyon Area” in July 2009. This site clearance letter is based on findings provided within this report. 

This letter provides a tophole drilling prognosis and addresses seafloor conditions within a 2,000-foot 

radius of the proposed well location. The depth limit of the investigation is approximately two and a half 

seconds of two-way traveltime below the seafloor. A dynamically positioned drilling rig is planned to 

drill the well, therefore an anchor assessment is not needed. The assessment and enclosures presented 

with this letter comply with Bureau of Ocean Energy Management, Regulation and Enforcement 

(BOEMRE) guidelines provided in Notice To Lessees (NTL) No. 2008-G05 (Shallow Hazards Program) 

and NTL No. 2000-G20 (Deepwater Chemosynthetic Communities). Per Woodside’s request, on January 

10, 2011, this letter and supporting maps have been updated to meet the requirements as stated in new the 

NTL No. 2009-G40 (Deepwater Benthic Communities) 

METHODS 

The 3D seismic data used for this site clearance assessment were provided in SEG-Y format on a digital 

linear tape (DLT) tape, where the files were retrieved and saved on a secure server then processed for shallow 

hazards by C & C. The data were loaded into Seismic Micro Technology’s (SMT) Kingdom Suite 2D/3D 

Pak, Version 8.3 for interpretation. The time-migrated data volume was processed at a two-millisecond 

sample rate and was interpreted to two and a half seconds below sea level. The inlines of the CGG Veritas 

data set run west-east and are spaced at 65.62-foot (20-meter) intervals. The crosslines run north-south and 

are spaced at 82.02-foot (25-meter) intervals. 

A strong positive amplitude peak, flanked by troughs, represents the seafloor on the seismic volumes. 

Amplitude values are represented by IBM 32-bit floating-point numbers, identified during data loading. 

The data provided were adequate for regional screening of the seafloor and shallow geologic conditions. 

WELL LOCATION 

The coordinates and calls of the proposed surface location for GC451 Well “B” are tabulated below: 
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Coordinates Well 

X-Coordinate Y-Coordinate 

Latitude Longitude Calls From Block 451 

Green Canyon Area 

Well “B” 2,158,712.00’ 9,987,548.18’ 27°30’50.203” 91°24’01.981” FNL 7,492’ FWL 4,472’ 

The geodetic datum used for this project is the North American Datum 0f 1927 (NAD27) on the Clarke 1866 

Ellipsoid. The datum is projected using the Universal Transverse Mercator (UTM) Zone 15 North (15N). 

All grid units, including scales and measurements, are in U.S. Survey Feet. The surface hole location of the 

proposed GC451 Well “B” and the 2,000-foot radius are displayed on the Color-Shaded Bathymetry Map 

(Sheet 1), Seafloor Amplitude Map (Sheet 2), Seafloor Features Map (Sheet 3), and the Subsurface Features 

Map (Sheet 4). 

REGIONAL GEOLOGY 

The “Floyd” Prospect is located in the west-central Gulf of Mexico in an area designated as the Green 

Canyon Area by the BOEMRE. The study area lies on the upper to middle continental slope of offshore 

Louisiana. This area of the slope consists of diapiric highs and basin-like topography. Two types of 

depositional sequences are identified in the region, condensed and expanded sections. Condensed 

sections are deposited during high sea level stands and consist of slowly accumulated hemipelagic clays. 

The expanded sections are formed during low sea level stands and consist of rapidly accumulated, coarsegrained clastic deposits (sands and gravels) of variable thickness. 

The area where the well is planned is undergoing regional extension and localized compression where 

allochthonous salt movement is the primary influence on the seafloor and subsurface sediments. Salt 

within this area is shallow and located at a depth of approximately 1,110 to 2,400 feet below the seafloor. 

The underlying salt sheet is migrating toward the southeast and has formed the Timbalier Basin to the 

southeast of the proposed well location. 

BATHYMETRY AND SEAFLOOR GRADIENTS 

The water depth at the proposed GC451 Well “B” surface location is 3,212 feet below sea level (BSL). 

Within the 2,000-foot radius the seabed depth ranges from 3,065 feet BSL in the northern portion of the 

2,000-foot boundary to 3,280 feet BSL at the southeastern portion of the 2,000-foot boundary in Block 

GC451 (Sheet 1). Water depths in the survey area were determined by applying the 1993 Advocate and 

Hood empirical time-depth model for calculating water depth in the northwest Gulf of Mexico. This 

equation is: D = 0.1105 - 5066.9193T + 468.6693T2

 - 554.7107T3 + 340.7019T4 - 116.9910T5 + 

20.7280T6

 - 1.4658T7, where D = water depth in feet and T = one-way traveltime in seconds. 

The seafloor at the proposed well site is sloping to the southeast at an average gradient of 1.5° (Sheet 1, 

Figure No. 1). Potential seafloor hazards identified within the 2,000-foot radius include seafloor faulting 

with localized gradients not exceeding 24°. The well site is proposed between two normal fault scarps 

striking east to west and southwest to northeast, respectively. The fault scarps are located due north and 

south at a distance of 617 feet and 384 feet, respectively, of the proposed Well “B” location. 

SEAFLOOR HAZARDS 

The seafloor reflector displays a range of low to moderate amplitudes within the 2,000-foot radius. In general 

the seafloor exhibits moderate amplitudes suggesting finely textured seafloor sediments that are likely 

comprised of hemipelagic clay (Sheet 2; Figure No. 2). Areas of low return identified on the fault scarp faces 

are attributed to the high angle of seabed where signal reflection is low. This lower amplitude likely results 

from the seismic signal being deflected away from the hydrophones by the high angle of incidence of the 

fault scarp face. 
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At the well location no seafloor hazards are present that might pose a problem for drilling activities. Several 

fault scarps are identified within the 2,000-foot radius, with scarps to the north and south, exhibiting 45 and 

50 feet, respectively, of seafloor displacement (Sheet 3) with no recent slumping evident along faults. No 

other significant seafloor features are located at the proposed Well “B” location that could interfere with 

drilling activities. 

POTENTIAL DEEPWATER BENTHIC COMMUNITIES 

High-amplitude seafloor anomalies are a potential indicator of carbonates and deepwater benthic community 

habitats. The seafloor at the proposed well location, and surrounding 2,000-foot radius, contains no low or 

high positive seafloor amplitudes associated with fluid expulsion or mounded carbonates representing 

potential deepwater benthic communities. 

The nearest reported deepwater benthic community is located in Block 272, Green Canyon Area, 

approximately 13 miles northwest of the proposed Well “B” location according to the BOEMRE (NTL 

No. 2009-G40). While, according to NTL 2009-G40, deepwater benthic communities are not know to 

exist within the planned well area, deepwater benthic communities are known to exist in similar geologic 

conditions to those located north of Well “B”. Mound features with associated expulsion and higher 

amplitudes are evident in the extreme northern portion of Block 451 and southern portion of Block 467, 

outside of the 2,000-foot radius. No areas of potential deepwater benthic communities are identified 

within 2,000 feet of the proposed location (Figure Nos. 3 and 4). 

MAN-MADE HAZARDS 

A review of company and BOEMRE data shows that no pipelines, umbilicals, wells, or platforms are located 

within a 2,000-foot radius of the proposed well location (Sheet 3). Man-made objects are below the 

resolution of 3D seismic data, thus unknown objects may exist at the well site. The drilling location of Well 

“B” is free from any known man-made hazards and infrastructure. 

SUBSURFACE GEOHAZARDS AND STRATIGRAPHY 

Five stratigraphic units of distinct seismic character were assessed (Sheet 4; Figure Nos. 3 and 4). 

Woodside provided C & C with check shot survey data used to derive the total vertical depth (TVD) in 

feet from the corresponding two-way traveltime in seconds. From these values an equation was derived 

that calculates structure depth below sea level: 

Y = 386.98(x2

) + 1,963.5x 

Where Y = depth below sea level in feet and x = two-way traveltime in seconds. A detailed description of 

the sequence units can be found in the 2009 Shallow Hazard Report, “Floyd” Prospect, Block 451 (OCSG-32509), Green Canyon Area. 

Subsurface deposition in the upper 213 feet, Unit A, occurred during a high sea level stand and is 

considered a “condensed section”. This unit is likely comprised of hemipelagic clays laid down as a 

drape deposit and interbedded layers of fine-grained turbidites, or thin mass transport deposits, and some 

possible sands (Figure Nos. 3 and 4). Unit A is categorized by uniform parallel reflectors, which are 

discontinuous within the 2,000-foot radius, only as a result of faulting from subsurface salt. No slumping 

or mass transport deposits are evident along the downthrown side of faulting within the 2,000-foot radius. 

At the well bore, Unit B contains low to moderate amplitude, parallel reflectors, at the top of the unit, 

which become deformed with depth due to faulting (Figure Nos. 3 and 4). The Unit B sequence is 

identified 213 to 461 feet below the mudline, with slumping and mass transport deposits evident within 

this unit, not at the well bore but within the 2,000-foot radius. This unit has the characteristics resembling 

an “expanded section” associated with a lower sea level stand. Some of the reflectors appear to be 
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4

truncated indicating a possible unconformity associated with changes in surface morphology. Faulting 

within this unit has caused extensive deformation and limited continuity of the sediments. 

Unit C consists of low to moderate amplitude parallel to chaotic reflectors with variable acoustic 

impedance and is found 461 to 783 feet below the mudline (Figure Nos. 3 and 4). The top of Unit C 

represents an unconformity, resulting from eroded uplifted beds. Moderate reflectors with parallel to 

discontinuous orientation disrupted by intense faulting comprise Unit C. Increased shear strength may 

occur below Unit C due to the unconformity. Uniform parallel reflectors extend east to west whereas the 

reflectors are discontinuous from north to south where faults are encountered. Faults are numerous 

throughout this unit with four instances occurring along the well bore. The first intersect crosses the well 

bore 511 feet below the mudline (1.470 seconds) within this unit. The lower portion of this unit is 

comprised of chaotic reflectors with low amplitude values likely saturated by fluid resulting from 

dissolution of the salt. The seafloor scarp located 50 feet south of the proposed surface location intersects 

the drilling path in this unit. 

Unit D is characterized by discontinuous chaotic reflectors showing primarily low to moderate amplitudes 

between 783 to 1,522 feet below the mudline. Low amplitude chaotic reflectors are evident at the top of 

the unit (Figure Nos. 3 and 4). Sediments within this unit are highly deformed due to extensive faulting 

and a possible fault intersects the well bore in the upper portion of the unit. Two identifiable faults 

intersect the well bore at 872 feet below the mudline (1.585 seconds) and 1,039 feet below the mudline 

(1.637 seconds). At a depth of approximately 1,185 feet BML, Horizon 4 is slightly apparent and 

moderate to high amplitudes are evident extending to the top of salt. One fault is evident within this 

transition zone above the top of salt, 1,376 feet below the mudline (1.740 seconds). The change in 

seismic character within this section could be the possible result of lithological differences as compared to 

the upper section, or a function of salt dissolution/sediment interaction, and likely a combination of both. 

Higher amplitudes are present at this location and at the salt/sediment interface. This region of higher 

amplitudes associated with the top of salt, are extensively deformed due to the salt/sediment interaction. 

The proposed Well “B” location will pierce the top of salt (1,522 feet below the mudline) at the base of 

this unit. The unpredictable nature of salt and its movement increases the risk of well bore stability at the 

salt/sediment interface. 

SHALLOW GAS 

Anomalies of very high amplitude, commonly termed bright spots, are interpreted as potential regions of 

fluid/gas saturation usually associated with porous sands. Shallow gas is interpreted with amplitude 

levels and the gas risk is assessed as being at one of four levels. These are: 

• Negligible - No amplitude anomalies or other gas indicators present. 

• Low risk of gas - Generally indicated by increased amplitude (2-3x background level) 

and phase reversal. This may also include diffuse areas of gas blanking. 

• Moderate risk of gas - Generally indicated by high amplitude (3-4x background level) 

and phase reversal. 

• High risk of gas - Generally indicated by the highest amplitudes (in excess of 4x 

background level), phase reversal, and a combination of other attributes indicative of 

the presence of gas, particularly velocity pull-down and masking of underlying 

sediments. Stratigraphic and structural settings may also be taken into account. 

No high amplitude subsurface amplitude anomalies are noted at the location of the proposed well bore 

(Sheet 4; Figure No. 5). A negligible to moderate risk of shallow gas exists along the well bore for the 

proposed Well “B” drilling site. 
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5

SHALLOW WATER FLOW (SWF) 

Shallow Water Flows (SWF) are overpressured unconsolidated sands encountered in the tophole sections 

of some wells drilled in the deepwater areas of the Gulf of Mexico. Sands with SWF potential often lie 

below a seal that prevents dewatering and compaction after deposition. The sands are usually 

unconsolidated and overpressured. The pressure rises with overburden causing a potentially disastrous 

hazard for drilling operations. The nearest reported shallow water flows occurred approximately 24 and 

25 miles northeast and northwest, respectively, of the proposed well site. A moderate severity shallow 

water flow event occurred during ERT’s drilling of GC282 Well No. 1 (OCS-G-16727) at a depth of 

2,121 feet below the mudline. BHP’s GC237 Well No. 3 (OCS-G-15563) encountered a low severity 

shallow water flow at a depth of 720 feet below the mudline. These shallow water flow events occurred 

in the northeastern portion of the Green Canyon Area and are attributed to deposition of the Mississippi 

Fan system. The third closest shallow water flow event occurred at BP’s Well No. 2 (OCS-G-12205) 

recorded as a low severity event 1,354 feet below the mudline in GC181. Well integrity was maintained 

at all three drilling sites. No seismic data was available to correlate the sand prone high SWF potential 

units to the Well “B” location. 

The assessment of seismic profiles suggests the region is highly faulted and stratigraphy is greatly 

impacted by salt induced uplift and migration. No direct indicators of channelized sediments are present 

along the proposed drilling site. However, in complexly faulted structures, formation pressures may be 

compartmentalized and may vary between different fault blocks. Areas with extensive shallow faulting 

are also vulnerable to low-margin drilling conditions. The overall risk of shallow water flow is negligible 

to moderate at the well location. Unit C has the highest potential for a shallow water flow event due to 

the sediments exhibiting characteristics similar to mass transport deposits covered by a rapidly deposited 

layer of sediments. A tophole prognosis chart summarizing subsurface conditions and shallow water flow 

potential is provided as Figure No. 5.

GAS HYDRATES 

Gas hydrates are in ice crystalline form of gas hydrocarbons in deepwater marine environments where the 

conditions of pressure and temperature are favorable. The hydrate stability zone is the depth interval 

between the seafloor and the point where the hydrate is no longer stable in form. The thermal gradient of 

the seabed soils determines the depth of the hydrate stability zone base. The acoustic impedance contrast 

caused between the hydrate and free gas trapped at the base of the hydrate stability zone forms a Bottom 

Simulating Reflector (BSR) on seismic profiles. This BSR reflector cross cuts the normal seismic 

stratigraphy, much like a bottom multiple. 

The areas where seafloor gas hydrates accumulate in the near-surface sediments of the Gulf of Mexico are 

generally unfavorable sites for drilling operations. Irregular seafloor topography, gas seeps, gas 

chimneys, seafloor hydrates and chemosynthetic communities may all be found in close association. 

There was no indication of any obvious BSRs on the 3D data collected in Block 451, Green Canyon Area. 

Mounds located north of the Well “B” location have the potential for gas hydrate association however, the 

well site remains free from any potential hydrate accumulation. 

SURFACE CONDUCTOR JETTING ASSESSMENT 

The Surface Conductor Jetting Assessment for the upper 120 milliseconds (~300 feet) of the 3D 

exploration seismic data is included as Figure No. 6 (assumed velocity of 5,000 feet/second). The 

interpreted soil lithology from the seismic profiles is presented as part of the assessment. 

The near seafloor seismic stratigraphy at the drill site is characterized by alternating low to moderate 

amplitude reflectors representing primarily Holocene and Late Pleistocene clay beds with possible 
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730 EAST KALISTE SALOOM ROAD, LAFAYETTE, LOUISIANA 70508 

6

interbedded layers of fine-grained debris flows. A possible unconformity exists approximately 213 feet 

BML at the boundary between Unit A and B. Unit B has severely faulted components and it is 

recommended to set the casing below this faulted zone. 

CONCLUSIONS 

The proposed surface well site location is clear of geological constraints. The seafloor within the 2,000-foot 

radius of the drill location contains two fault scarps, though none intersect the proposed Well “B” surface 

location. Drilling efforts should note the positions of these features and avoid as necessary. 

No high or low seafloor amplitudes, that may indicate the occurrence of hard ground or carbonates or 

potential expulsion, are found within 2,000 feet of the proposed Well “B” surface location. 

No known infrastructure exists in proximity to the Well “B” location. 

 

A negligible to moderate risk of shallow gas exists along the majority of the well bore for the proposed 

Well “B” drilling site. 

A possible lithological change or a function of salt dissolution/sediment interaction occurs at a depth of 1,185 

to 1,522 feet below the mudline. Caution should be used when drilling through this interval and the top of 

salt due to the unpredictable nature of salt movement, dissolution, and possible pressure differences. 

The assessment of seismic profiles suggests all units exhibit a negligible to moderate risk of shallow 

water flow at the well location. 

Thank you for this opportunity to be of service. Please contact us if you have any questions concerning 

this assessment. 

Sincerely yours, 

Hallie Graves 

Marine Geologist 

Enclosures 

Figure No. 1. Seafloor rendering and features identified within 2,000 feet of well location. 

Figure No. 2. Seafloor amplitudes evident within the study area. 

Figure No. 3. 3D seismic Inline 2642 through Well “B”. 

Figure No. 4. 3D seismic Crossline 2519 through Well “B”. 

Figure No. 5. Tophole prognosis chart for the proposed Well “B” in Block 451, Green Canyon Area. 

Figure No. 6. Surface Conductor Jetting Assessment for Proposed Well “B”. 

Figure No. 7. Extracted wavelet and power spectrum at Proposed Well “B” in Block 451, Green Canyon 

Area. 

Sheet 1. Color-Shaded Bathymetry Map 

Sheet 2. Seafloor Amplitude Map 

Sheet 3. Seafloor Features Map 

Sheet 4. Subsurface Features Map 
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1

January 12, 2011 

Woodside Energy Ltd. 

830 West Causeway Approach, Suite 1000 

Mandeville, LA 70471 

Attn: Mr. Doug Lumpkin 

Site Clearance Letter 

Proposed Well “C” 

Block 451 (OCS-G-32509), Green Canyon Area 

INTRODUCTION 

Woodside Energy Ltd. (Woodside) contracted C & C Technologies, Inc. (C & C) to prepare a well site 

clearance letter for the drilling location of the proposed Well “C” in Block 451 (OCS-G-32509), Green 

Canyon (GC) Area. The data used for the site clearance letter is an exploration-quality 3D seismic 

volume, collected by CGG Veritas between 1999 and 2000, provided by Woodside. C & C completed the 

geohazard report titled “Shallow Hazard Report, “Floyd” Prospect, Block 451 (OCS-G-32509), Green 

Canyon Area” in July 2009. This site clearance letter is based on findings provided within this report. 

This letter provides a tophole drilling prognosis and addresses seafloor conditions within a 2,000-foot 

radius of the proposed well location. The depth limit of the investigation is approximately two and a half 

seconds of two-way traveltime below the seafloor. A dynamically positioned drilling rig is planned to 

drill the well, therefore an anchor assessment is not needed. The assessment and enclosures presented in 

this letter comply with Bureau of Ocean Energy Management, Regulation and Enforcement (BOEMRE) 

guidelines provided in Notice to Lessees (NTL) No. 2008-G05 (Shallow Hazards Program) and NTL No. 

2000-G20 (Deepwater Chemosynthetic Communities). Per Woodside’s request, on January 10, 2011, this 

letter and supporting maps have been updated to meet the requirements as stated in new the NTL No. 

2009-G40 (Deepwater Benthic Communities) 

METHODS 

The 3D seismic data used for this site clearance assessment were provided in SEG-Y format on a digital 

linear tape (DLT) tape, where the files were retrieved and saved on a secure server then processed for shallow 

hazards at C & C. The data were loaded into Seismic Micro Technology’s Kingdom Suite 2D/3D Pak, 

Version 8.3 (SMT) for interpretation. The data volume (Time Migrated SEG-Y data) was processed at a 2-

millisecond sample rate and was interpreted to two and a half seconds below sea level. The inlines of the 

CGG Veritas data set run west-east and are spaced at 65.62-foot (20-meter) intervals. The crosslines run 

north-south and are spaced at 82.02-foot (25-meter) intervals. 

A strong positive amplitude peak, flanked by troughs, represents the seafloor on the seismic volumes. 

Amplitude values are represented by IBM 32-bit floating-point numbers, identified during data loading. 

The data provided were adequate for regional screening of the seafloor and shallow geologic conditions. 

WELL LOCATION 

The coordinates and calls of the proposed surface location for GC451 Well “C” are tabulated below: 
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730 EAST KALISTE SALOOM ROAD, LAFAYETTE, LOUISIANA 70508 

2

Well Coordinates 

X-Coordinate Y-Coordinate 

Latitude Longitude Calls From Block 451 

Green Canyon Area 

Well “C” 2,159,111.96’ 9,990,572.09’ 27°31’20.097” 91°23’57.105” FNL 4,468’ FWL 4,872’ 

The geodetic datum used for this project is the North American Datum of 1927 (NAD27) on the Clarke 1866 

Ellipsoid. The datum is projected using the Universal Transverse Mercator (UTM) Zone 15 North (15N). 

All grid units, including scales and measurements, are in U.S. Survey Feet. The surface hole location of the 

proposed GC451 Well “C” and the 2,000-foot radius are displayed on the Color-Shaded Bathymetry Map 

(Sheet 1), Seafloor Amplitude Map (Sheet 2), Seafloor Features Map (Sheet 3), and the Subsurface Features 

Map (Sheet 4). 

REGIONAL GEOLOGY 

The “Floyd” Prospect is located in the west-central Gulf of Mexico in an area designated as the Green 

Canyon Area by the BOEMRE. The study area lies on the upper to middle continental slope of offshore 

Louisiana. This area of the slope consists of diapiric highs and basin-like topography. Two types of 

depositional sequences are identified in the region, condensed and expanded sections. Condensed 

sections are deposited during high sea level stands and consist of slowly accumulated hemipelagic clays. 

The expanded sections are formed during low sea level stands and consist of rapidly accumulated, coarsegrained clastic deposits (sands and gravels) of variable thickness. 

The area where the well is planned is undergoing regional extension and localized compression where 

allochthonous salt movement is the primary influence on the seafloor and subsurface sediments. Salt 

within this area is shallow and located at a depth of approximately 1,110 to 2,400 feet below the seafloor. 

The underlying salt sheet is migrating toward the southeast and has formed the Timbalier Basin to the 

southeast of the proposed well location. 

 

BATHYMETRY AND SEAFLOOR GRADIENTS 

The water depth at the proposed GC451 Well “C” surface location is 3,038 feet below sea level (BSL). 

Within the 2,000-foot radius the seabed depth ranges from 3,020 feet BSL in the eastern portion of the 

2,000-foot boundary to 3,160 feet BSL at the southern portion of the 2,000-foot boundary in Block 

GC451 (Sheet 1). Water depths in the survey area were determined by applying the 1993 Advocate and 

Hood empirical time-depth model for calculating water depth in the northwest Gulf of Mexico. This 

equation is: D = 0.1105 - 5066.9193T + 468.6693T2

 - 554.7107T3 + 340.7019T4 - 116.9910T5 + 

20.7280T6

 - 1.4658T7, where D = water depth in feet and T = one-way traveltime in seconds. 

The seafloor at the proposed well site is on the northwestern side of an elongated fault block where the 

seafloor slopes to the northwest on the backside of the uplift with an average gradient of 2.3° (Sheet 1; 

Figure No. 1). Potential seafloor hazards identified within the 2,000-foot radius include seafloor faulting 

with localized gradients not exceeding 14°. The well site is proposed on the top of the uplift where 

normal faulting occurs to the north and south, striking southwest to northeast. The fault scarps are located 

due north and south at a distance of 1,460 feet and 532 feet, respectively, of the proposed Well “C” 

location. 

SEAFLOOR HAZARDS 

The seafloor reflector displays a range of low to moderate amplitudes within the 2,000-foot radius. In general 

the seafloor exhibits moderate amplitudes suggesting finely textured seafloor sediments that are likely 

comprised of hemipelagic clay (Sheet 2; Figure No. 2). 
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3

At the well location no seafloor hazards are present that might pose a problem for drilling activities. A few 

fault scarps are identified within the 2,000-foot radius, with the closest exhibiting 50 and 35 feet, respectively, 

of seafloor displacement with no recent slumping evident along the fault scarps (Sheet 3). No other 

significant seafloor features are located at the proposed Well “C” location that could interfere with drilling 

activities. 

POTENTIAL DEEPWATER BENTHIC COMMUNITIES 

High-amplitude seafloor anomalies are a potential indicator of carbonates and deepwater benthic community 

habitats. The seafloor at the proposed well location, and surrounding 2,000-foot radius, contains no low or 

high positive seafloor amplitudes associated with fluid expulsion or mounded carbonates representing 

potential deepwater benthic communities. 

The nearest reported deepwater benthic community is located in Block 272, Green Canyon Area, 

approximately 13 miles northwest of the proposed Well “C” location according to the BOEMRE (NTL 

No. 2009-G40). While, according to NTL No. 2009-G40, deepwater benthic communities are not know 

to exist within the planned well area, deepwater benthic communities are known to exist in similar 

geologic conditions to those located north of Well “C”. Mound features with associated expulsion and 

higher amplitudes are evident in the extreme northern portion of Block 451 and southern portion of Block 

467, outside of the 2,000-foot radius. No areas of potential deepwater benthic communities are identified 

within 2,000 feet of the proposed location (Figure Nos. 3 and 4). 

MAN-MADE HAZARDS 

A review of company and BOEMRE data shows that no pipelines, umbilicals, wells, or platforms are located 

within a 2,000-foot radius of the proposed well location (Sheet 3). Man-made objects are below the 

resolution of 3D seismic data, thus unknown objects may exist at the well site. The drilling location of Well 

“C” is free from any known man-made hazards and infrastructure. 

SUBSURFACE GEOHAZARDS 

Five stratigraphic units of distinct seismic character were assessed (Sheet 4; Figure Nos. 3 and 4). 

Woodside provided C & C with check shot survey data used to derive the total vertical depth (TVD) in 

feet from the corresponding two-way traveltime in seconds. From these values an equation was derived 

that calculates structure depth below sea level: 

Y = 386.98(x2

) + 1,963.5x 

Where Y = depth below sea level in feet and x = two-way traveltime in seconds. A detailed description of 

the sequence units can be found in the 2009 Shallow Hazard Report, “Floyd” Prospect, Block 451 (OCSG-32509), Green Canyon Area. 

Subsurface deposition in the upper 147 feet, Unit A, occurred during a high sea level stand and is 

considered a “condensed section”. This unit is likely comprised of hemipelagic clays laid down as a 

drape deposit and interbedded layers of fine-grained turbidites, or thin mass transport deposits, and some 

possible sands (Figure Nos. 3 and 4). Unit A is categorized by uniform parallel reflectors, which are 

discontinuous only as a result of faulting from subsurface salt. No slumping or mass transport deposits 

are evident along the downthrown side of faulting within the 2,000-foot radius. 

At the well bore, Unit B contains low to moderate amplitude, parallel and discontinuous reflectors 

throughout the unit, which become deformed at depth due to faulting (Figure Nos. 3 and 4). The Unit B 

sequence is identified 147 to 381 feet below the mudline with mass transport deposits more evident 

within this unit. This unit has the characteristics resembling an “expanded section” associated with a 

lower sea level stand. Some of the reflectors appear to be truncated indicating a possible unconformity 
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730 EAST KALISTE SALOOM ROAD, LAFAYETTE, LOUISIANA 70508 

4

associated with changes in surface morphology. Low amplitude reflectors are interpreted to indicate finegrained silts and clays with mass movement deposits exhibiting higher amplitude values suggesting more 

sand rich sediments. The seafloor fault located 1,460 feet north of the proposed surface location 

intersects the drilling path in this unit. 

Unit C consists of low to moderate amplitude, parallel to chaotic reflectors, with variable acoustic 

impedance and is found 381 to 790 feet below the mudline (Figure Nos. 3 and 4). The top of Unit C 

represents an unconformity, resulting from eroded uplifted beds. Moderate reflectors with parallel to 

discontinuous orientation disrupted by intense faulting comprise Unit C. One fault intersects the well 

bore 561 feet below the mudline (1.430 seconds). Increased shear strength may occur below Unit C due 

to the unconformity. The higher amplitude values are interpreted to be resulting from sand rich deposits 

likely associated with mass movement deposits having thicker stratigraphic deposition in this area. The 

lower portion of this unit is comprised of chaotic reflectors with low amplitude values likely saturated 

with fluid from dissolution occurring above the top of salt. 

Unit D is characterized by discontinuous, chaotic reflectors, showing primarily low to moderate 

amplitudes between 790 to 1,857 feet below the mudline. Low amplitude chaotic reflectors are evident in 

the upper portion of the unit (Figure Nos. 3 and 4). The base of Unit D along the well bore is the 

stratigraphic contact with the top of salt (1,857 feet below the mud line) due to Horizon 4 being 

indistinguishable. At a depth of 1,497 feet BML, moderate to high amplitudes are evident extending to 

the top of salt. These higher amplitude reflectors are contained within a localized depression on the top of 

salt. The change in seismic character within this section could be the possible result of lithological 

differences as compared to the upper section, or a function of salt dissolution/sediment interaction, and 

likely a combination of both. The well bore will pierce the top of salt (1,857 feet below the mudline) on 

the edge of a depression where the higher amplitude reflectors are present. The unpredictable nature of 

salt and its movement increases the risk of wellbore stability at the salt/sediment interface. 

SHALLOW GAS 

Anomalies of very high amplitude, commonly termed bright spots, are interpreted as potential regions of 

fluid/gas saturation usually associated with porous sands. Shallow gas is interpreted with amplitude 

levels and the gas risk is assessed as being at one of four levels. These are: 

• Negligible - No amplitude anomalies or other gas indicators present. 

• Low risk of gas - Generally indicated by increased amplitude (2-3x background level) 

and phase reversal. This may also include diffuse areas of gas blanking. 

• Moderate risk of gas - Generally indicated by high amplitude (3-4x background level) 

and phase reversal. 

• High risk of gas - Generally indicated by the highest amplitudes (in excess of 4x 

background level), phase reversal, and a combination of other attributes indicative of 

the presence of gas, particularly velocity pull-down and masking of underlying 

sediments. Stratigraphic and structural settings may also be taken into account. 

No high amplitude subsurface amplitude anomalies are noted at the location of the proposed well bore 

(Sheet 4; Figure No. 5). A low to negligible risk of shallow gas exists along the well bore for the 

proposed Well “C” drilling site. Due to the subsurface salt being so shallow and extensive throughout the 

region, the only form of structural closures are the fault blocks that have formed, however no high 

amplitudes appear to be associated with these features. 
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5

SHALLOW WATER FLOW (SWF) 

Shallow Water Flows (SWF) are overpressured unconsolidated sands encountered in the tophole sections 

of some wells drilled in the deepwater areas of the Gulf of Mexico. Sands with SWF potential often lie 

below a seal that prevents dewatering and compaction after deposition. The sands are usually 

unconsolidated and overpressured. The pressure rises with overburden causing a potentially disastrous 

hazard for drilling operations. The nearest reported shallow water flows occurred approximately 24 and 

25 miles northeast and northwest, respectively, of the study area. A moderate severity shallow water flow 

event occurred during ERT’s drilling of GC282 Well No. 1 (OCS-G-16727) at a depth of 2,121 feet 

below the mudline. BHP’s GC237 Well No. 3 (OCS-G-15563) encountered a low severity shallow water 

flow at a depth of 720 feet below the mudline. These shallow water flow events occurred in the 

northeastern portion of the Green Canyon Area and are attributed to deposition of the Mississippi Fan 

system. The third closest shallow water flow event occurred at BP’s Well No. 2 (OCS-G-12205) 

recorded as a low severity event 1,354 feet below the mudline in GC181. Well integrity was maintained 

at all three drilling sites. No seismic data was available to correlate the sand prone high SWF potential 

units to the Well “C” location. 

The assessment of seismic profiles suggests the region is highly faulted and stratigraphy is greatly 

impacted by salt induced uplift and migration. No direct indicators of channelized sediments are present 

along the proposed drilling path. However, in complexly faulted structures, formation pressures may be 

compartmentalized and may vary between different fault blocks. Areas with extensive shallow faulting 

are also vulnerable to low-margin drilling conditions. The overall risk of shallow water flow is negligible 

to moderate, at the well location. Unit C has the highest potential for a shallow water flow event due to 

the sediments exhibiting characteristics similar to mass transport deposits covered by a rapidly deposited 

layer of higher amplitudes. A tophole prognosis chart summarizing subsurface conditions and shallow 

water flow potential is provided as Figure No. 5.

GAS HYDRATES 

Gas hydrates are in ice crystalline form of gas hydrocarbons in deepwater marine environments where the 

conditions of pressure and temperature are favorable. The hydrate stability zone is the depth interval 

between the seafloor and the point where the hydrate is no longer stable in form. The thermal gradient of 

the seabed soils determines the depth of the hydrate stability zone base. The acoustic impedance contrast 

caused between the hydrate and free gas trapped at the base of the hydrate stability zone forms a Bottom 

Simulating Reflector (BSR) on seismic profiles. This BSR reflector cross cuts the normal seismic 

stratigraphy, much like a bottom multiple. 

The areas where seafloor gas hydrates accumulate in the near-surface sediments of the Gulf of Mexico are 

generally unfavorable sites for drilling operations. Irregular seafloor topography, gas seeps, gas 

chimneys, seafloor hydrates and deepwater benthic communities may all be found in close association. 

There was no indication of any obvious BSRs on the 3D data collected in Block 451, Green Canyon Area. 

SURFACE CONDUCTOR JETTING ASSESSMENT 

The Surface Conductor Jetting Assessment for the upper 120 milliseconds (~300 feet) of the 3D 

exploration seismic data is included as Figure No. 6 (assumed velocity of 5,000 feet/second). The 

interpreted soil lithology from the seismic profiles is presented as part of the assessment. 

The near seafloor seismic stratigraphy at the drill site is characterized by alternating low to moderate 

amplitude reflectors representing primarily Holocene and Late Pleistocene clay beds with possible 

interbedded layers of fine-grained debris flows. A possible unconformity exists approximately 147 feet 
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730 EAST KALISTE SALOOM ROAD, LAFAYETTE, LOUISIANA 70508 

6

BML at the boundary between Unit A and B. The fault scarp located just north of the well locations 

intersects the well bore near this boundary. It is recommended to set the casing below the faulted zone. 

CONCLUSIONS 

The proposed surface well site location is clear of geological constraints. The seafloor within the 2,000-foot 

radius of the drill location does contain a few fault scarps. Drilling efforts need to take note of the positions 

of these features and avoid as necessary. 

No high or low seafloor amplitudes, that may indicate the occurrence of hard ground, carbonates, or potential 

expulsion, are found within 2,000 feet of the proposed Well “C” surface location. 

No known infrastructure exists in proximity of the proposed Well “C” location. 

 

A low to negligible risk of shallow gas exists along the majority of the well bore for the proposed Well 

“C” drilling site. 

A possible lithological change or a function of salt dissolution/sediment interaction occurs at a depth of 

1,497 to 1,857 feet below the mudline. Caution should be used when drilling through this interval and the 

top of salt due to the unpredictable nature of salt movement, dissolution, and possible pressure 

differences. 

The assessment of seismic profiles suggests all units exhibit a negligible to moderate risk of shallow 

water flow at the well location. 

Thank you for this opportunity to be of service. Please contact us if you have any questions concerning 

this assessment. 

Sincerely yours, 

Hallie Graves 

Marine Geologist 

Enclosures 

Figure No. 1. Seafloor rendering and features identified within 2,000 feet of well location. 

Figure No. 2. Seafloor amplitudes evident within the anchor spread. 

Figure No. 3. 3D seismic Inline 2688 through Well “C”. 

Figure No. 4. 3D seismic Crossline 2524 through Well “C”. 

Figure No. 5. Tophole prognosis chart for the proposed Well “C” in Block 451, Green Canyon Area. 

Figure No. 6. Surface Conductor Jetting Assessment for Proposed Well “C”. 

Figure No. 7. Extracted wavelet and power spectrum at Proposed Well “C” in Block 451, Green Canyon 

Area 

Sheet 1. Color-Shaded Bathymetry Map 

Sheet 2. Seafloor Amplitude Map 

Sheet 3. Seafloor Features Map 

Sheet 4. Subsurface Features Map 


OCS-G-25144

CHEVRON

OCS-G-25145

KERR-MCGEE

OCS-G-25155

MURPHY

OCS-G-25156

MURPHY

OCS-G-28081

WOODSIDE

OCS-G-25143

MAXUS

OCS-G-25149

MAXUS

OCS-G-28078

WOODSIDE OCS-G-32509

WOODSIDE

GC408

GC494 GC495 GC496

GC406 GC407

GC452

GC450

GC451

2,000'

2,000'

2,000'

Face of

Escarpment

Escarpment

Face of

High seafloor reflectivity (high amplitude seafloor) - C & C job #061593

Expulsion

Fault scarp with seafloor displacement (Hachures on downthrown side)

Possible fluid expulsion zone associated with low amplitude seafloor

anomalies

High positive amplitude anomalies associated with potential mounded

carbonates or hard grounds on seafloor

Base of escarpment (Hachures on upslope side)

Crest of escarpment (Hachures on downthrown side)

Mass movement deposits

Seafloor gully, sedimentation pathway

SITE CLEARANCE

SEAFLOOR FEATURES MAP

"FLOYD" PROSPECT

WELLS "A", "B", & "C" LOCATIONS

OCS-G-32509

BLOCK 451

GREEN CANYON AREA

CGG survey inline number (Inline spacing = 65.62 feet)

CGG survey crossline number (Crossline spacing = 82.02 feet)

Mounds

Depression
Attachment I 

Stratigraphic Column 
Attachment J 

Vicinity Map 

Attachment K 

Consistency

Certificate

Attachment L 

Blowout Scenario 

with 

Assumptions and Calculations 
(j) Blowout Scenario 

1) Purpose 

Pursuant with 30 CFR 250.213(g), 250.219, 250.250 and NTL No. 2010-N06, this 

Appendix J provides a blowout scenario description, further information regarding any 

potential oil spill, the assumptions and calculations used to determine the worst case 

discharge and the measures taken to firstly enhance the ability to prevent a blowout and 

secondly to respond and manage a blowout scenario if it occurred. 

2) Background 

This attachment has been developed to document the additional information requirements 

for Exploration Plans as requested by NTL No. 2010-N06 in response to the explosion 

and sinking of the Mobile Offshore Drilling Unit (MODU) ‘Deepwater Horizon’ and the 

resulting sub-sea well blowout and recovery operations of the exploration well at the 

MC-252 ‘Macondo’ location. 

3) Information Requirements 

a) Blowout scenario 

The GC-451 exploration well is drilled to the objective sands as outlined in the 

Geological and Geophysical Information Section of this Plan utilizing a typical subsea 

wellhead system, conductor, surface and intermediate casing program, and using a 

MODU rig with a marine riser and sub-sea BOP. A hydrocarbon influx and a well control 

event occurred from the objective followed by failure of the subsea BOP and marine riser and 

a blow-out to the seabed. The worst case discharge from the objective sands was modeled 

for flow up the well bore with no drill pipe in the hole. 
b) Estimated flow rate of the potential blowout 

Category Initial EP 

Type of Activity Exploratory Drilling 

Facility Location (area/block) GC 451 Well Location “A” 

Facility Designation MODU 

Distance to Nearest Shoreline (miles) 109 

Uncontrolled blowout (volume per day) 159,951 bbl

Type of Fluid(s) Crude 

c) Total volume and maximum duration of the potential blowout 

Category Initial EP 

Duration of flow (days) 21 days to contract/mob rig 

99 days to drill relief well 

120 days total duration 

Total volume of spill (bbls) 5,735,000 Note: MBAL model used 

assuming depletion.* 

* Note: Our Analysis of the Floyd prospect indicates depletion drive as the primary drive 

mechanism. 
d) Potential for the well to bridge over 

Mechanical failure/collapse of the borehole in a blowout scenario is influenced by several 

factors including in-situ stress, rock strength and fluid velocities at the sandface. Given 

the substantial fluid velocities inherent in the blowout rate quoted above, it is possible 

that the borehole may fail/collapse/bridge over within the span of a week. 

e) Likelihood and measures taken for surface and/or sub-sea intervention to stop the 

blowout 

The likelihood of surface intervention to stop a blowout is high and is based on the 

following equipment specific to the MODU - Maersk Developer that has been contracted 

to do this drilling program: 

• Acoustic Secondary BOP Control System: The rig has a Kongsberg acoustic BOP 

control system fitted to the BOP. This system has the ability to communicate with the 

BOP from surface in the event of failure of the primary umbilical control system from the 

rig under a scenario such as a loss of the rig or marine riser. Control can be established 

either from the surface acoustic package on the rig or by deploying a second acoustic 

control package on the back of a supply boat. The system is configured to provide 

control over the following functions: - Blind / shear ram close - Pipe ram close - LMRP 

disconnect 

• ROV Secondary BOP Control System: The rig has two secondary ROV interface BOP 

control panels, one located on the lower BOP and a second located on the LMRP. This 

system is designed for an ROV hot stab to interface with the control panel and operate a 

specific function by direct hydraulic supply from the ROV. 

The system is configured to provide control over the following functions: - Blind / shear 

ram open and close - Casing (super) shear ram open and close - Auto shear sequence - 

Pipe rams open and close - LMRP disconnect - Wellhead disconnect The rig is equipped 

with two ROV’s which provides additional redundancy. The panels could also be 

operated by an ROV from independent supply boat in the event of a loss of rig scenario. 

The ROV panel has been tested during the month of June 2010, using the rig based ROV 

with the BOP on a wellhead on the seabed and the actual hot stab. A close of the blind 

shear rams was successfully achieved in 13 minutes using the ROV’s direct hydraulic 

supply. 

• Deadman / autoshear function: The rig is equipped with an automated sequence that 

closes the blind shear rams in the event of any of the following scenarios: - Inadvertent 

disconnect of the LMRP - Loss of both hydraulic pressure and electrical supply from the 

surface BOP control system No human interface is required once these systems are 

armed. These systems were satisfactorily tested during rig commissioning and again in 

June 2010. 
f) Availability of a rig to drill a relief well. 

Woodside currently has one deepwater MODU (Maersk Developer) on contract and 

located in the US GOM for exploration drilling. If the blowout scenario does not involve 

the loss or damage of the rig (eg: marine riser failure only), then the existing contracted 

rig may be available for drilling the relief well. Maersk Drilling owns and maintains 

spare riser joints and a spare BOP in the US GOM. If the blowout scenario involves 

significant damage or total loss of this rig then a replacement rig will be required to be 

contracted. The US GOM activity level currently supports a deepwater operating fleet of 

between 25 to 40 MODU’s with the majority of those rigs being dynamically positioned 

vessels. The GOM is considered a mature operating environment with a significant local 

rig fleet capable of conducting relief well operations. The ability to negotiate and 

contract a rig of similar capability under the scenario of a requirement to drill a relief well 

is considered high. 

This lease is located approximately 109 miles from the shoreline and there are no platforms

available in this block to untilize to drill a relief well. 

Contracting strategy: 

• Request rig availability from existing strategic partners in the US GOM where 

Woodside is a non-operating partner in an active drilling operation or a partner in the 

sharing of a rig. 

• Request rig availability from the wider GOM fleet through direct contact and 

negotiation and by utilizing the established communication network between the US 

GOM operator drilling organizations. 

g) Rig constraints 

The US GOM deepwater rig fleet consists of mainly 4th to 6th generation, dynamically 

positioned MODU’s which are capable of performing equivalent relief well operations at 

the GC-451 location. The smaller US GOM fleet of anchored MODU’s that can work in 

deepwater would have time and equipment constraints of mobilizing and setting up a 

deepwater anchoring spread at the GC-451 location and would not be the preferred option 

for the drilling of a relief well. 

h) Time taken to contract a rig, move it onsite and drill a relief well 

Between 2008 and 2010 the US GOM rig fleet has typically been close to 95% utilization 

on deepwater exploration and development projects for multiple US GOM operators. 

This high utilization means that any rig that is contracted for a relief well will likely have 

to suspend current operations on an existing well before moving to prepare for drilling a 

relief well. It is estimated that 14 days is typically required to suspend a well and pull the 

BOP and be ready to move to a new location. It is estimated a further 7 days is then 

required to mobilize and be ready to spud at the relief well location. 
• Since Woodside has the ability to respond to the appropriate worst-case spill scenario 

included in its regional OSRP submitted April 30, 2011 and since the worst-case scenario 

determined for this Plan does not replace the worst-case scenario in our regional OSRP, I 

hereby certify that Woodside has the capability to respond, to the maximum extent 

practicable, to a worst-case discharge, or a substantial threat of such a discharge, resulting 

from the activities proposed in this Plan. 

 

k) Measures taken to enhance ability to prevent a blow-out 

• Well design: Woodside uses a systematic well design process for the planning and 

construction of a well operation. This process involves an assurance plan covering each 

step of the well design and an independent peer review of the well design and of the 

shallow hazards and formation pressure hazards expected during drilling. These are the 

critical design steps required to minimize the potential for an unplanned well control 

event that could lead to a blowout. This process will also include a Professional Engineer 

review and approval of the final casing design. 

Woodside’s drilling philosophy is to provide a detailed pre-drill assessment of formation 

pressure and provide an overbalanced mud weight for the safe drilling of the well. For an 

exploration well this may also include taking formation pressures to confirm the actual 

formation pressure during the well construction process and minimize the risk of an 

unplanned well control event. 

The well construction process also requires a systematic review and management 

acceptance of the start-up preparation work for the rig and crews and the third party 

technical audit work on the rig and the rig’s well control equipment. This measures the 

rig’s ability to handle an unplanned well control event and provide assurance that the rig 

can successfully mitigate a loss of well control event and prevent it from becoming a 

blowout scenario. 

 

• Barrier Philosophy: For the GC-451 exploration well design Woodside will require and 

use two independent barriers for both internal and external flow paths and conduct 

positive and negative testing to confirm integrity of those barriers in accordance with 

NTL No. 2010-N05. 

 

• Management of change protocol: Woodside uses a ‘Management of Change’ system 

for monitoring and approving changes in the well design or well construction that require 

a deviation from the approved Drilling Program. Where an unplanned result in the 

offshore operation requires a change or deviation from the approved drilling plan, a risk 

based decision with formal onshore management approval is required before continuing 

the operation. 

 

• BOP and well control equipment: The Maersk Developer has a 15k psi (6 ram / 2 

annular) Hydril BOP with primary and secondary BOP control systems. The BOP was 
delivered new in 2008. The BOP and well control equipment was audited during the rig 

construction and commissioning process by an independent third party. Prior to 

commencement of operations at the GC-451 location, a BOP certification package will be 

submitted as part of the APD process that details the compliance with the Original 

Equipment Manufacturer (OEM) and applicable federal regulations including NTL No. 

2010-N05. 

• Gas Handler: The Maersk Developer has an operational gas handler marine riser joint 

which is normally installed near the top of the marine riser below the moon pool. The 

purpose of the gas handler is to provide another means for closing an annular element 

near surface and capturing any gas that has found its way above the BOP and into the 

marine riser. The gas handler has the means to circulate this gas from under the closed 

annular in a controlled manner and back through conventional surface well control 

equipment. This item of well control equipment is relatively unique in the industry and 

has a direct application for deepwater operations. 

• BOP and well control equipment testing. To ensure effectiveness of the BOP and well 

control equipment, a testing program will be conducted prior to running the BOP and 

then during the well operations at the GC-451 well. This testing program will provide 

compliance with current federal regulations for pressure and function testing and will also 

provide periodic assurance on the performance of both primary and secondary BOP 

control systems including actual interface operations with the ROV and the ROV panel. 

• Well control training and drills. Woodside’s Well Control Manual requires that key 

nominated onshore and offshore positions including rig contractor personnel hold an 

IWCF, WELLCAP or equivalent well control training certificate, renewable every two 

years for the type of floating drilling operation being conducted. Woodside also monitors 

compliance for its personnel with the federal regulations and Sub-Part O for well control 

training. A comprehensive program of well control drills will be conducted offshore to 

ensure readiness to identify and then manage a well control situation and thereby 

minimize the potential for a well control event to lead to a blowout scenario. 

l) Arrangements for drilling a relief well 

Woodside maintains a master agreement with ‘Wild Well Control’ for advice, 

management, engineering, well kick pre and post modeling and resource support for an 

unplanned loss of well control event. In the event of any well control event, Wild Well 

Control would be contacted and mobilized if required to support Woodside’s operational 

team both in the onshore and offshore locations. During a significant loss of well 

control event, Woodside would mobilize up from a standard drilling support organization 

in Houston, Texas to a 24 hr / 7 days a week onshore capability utilizing local operations 

resources within the Woodside USA organization and the wider Woodside Energy 

organization in Australia. A conceptual relief well design will be prepared ahead of time 

and issued with the Application to Drill. This conceptual well design would be finalized 

based on the exact circumstance of the loss of well control event. 
Back-up long lead equipment equivalent to the original well design will be carried in 

stock to allow a rapid response. This includes a spare deepwater sub-sea wellhead 

system and the large OD casing (36”, 28” 22”, 18” and 16”) and the connectors required 

for the first part of the well. Smaller OD casing is considered widely available on the 

ground in the GOM and would be resourced out of existing inventory or from suppliers 

as required. 

Existing service agreements will be in place for support services including drilling fluids, 

casing running, cementing, ROV’s, solids control, mud logging, directional drilling, 

LWD/MWD, logging, boats and helicopters. 

Specialist services for range finding to drill the relief well in close proximity to the 

original wellbore at the reservoir depth will be provided through Vector Magnetics LLC 

as a sub-contractor to Baker Hughes Inteq under our existing directional drilling 

agreement. 

The GC-451 block has three well locations identified, with the corresponding 1500 ft 

radius around their locations cleared for shallow hazards as part of Exploration Plan N09436. A fourth location has been identified and the corresponding 2000 ft radius around 

its well location cleared for shallow hazards. This fourth well location has been submitted 

as a supplement to EP N-09436 as proposed well location “D”. Depending on the nature 

of the blowout scenario and the total depth required to intersect the blowout zone, these 

previously cleared areas would be reviewed for best suitability for the location of the 

relief well. After selecting the most suitable surface location a directional plan would be 

prepared and issued within a 48 hour period. 
Attachment M 

Environmental 

Impact Analysis 
1

Woodside Energy (USA) Inc. (Woodside)

Initial Exploration Plan 

Green Canyon Block 451 

OCS-G32509

(A) Impact Producing Factors 

ENVIRONMENTAL IMPACT ANALYSIS WORKSHEET 

Environment 

Resources 

Impact Producing Factors (IPFs) 

Categories and Examples 

Refer to recent GOM OCS Lease Sale EIS for a more complete list of IPFs 

Emissions 

(air, noise, 

light, etc.) 

Effluents 

(muds, 

cutting, other 

discharges to 

the water 

column or 

seafloor) 

Physical 

disturbances to the 

seafloor (rig or 

anchor 

emplacements, 

etc.) 

Wastes sent 

to shore for 

treatment 

or disposal 

Accidents 

(e.g., oil 

spills, 

chemical 

spills, H2S 

releases) 

Discarded 

Trash & 

Debris 

Site-specific at Offshore 

Location 

Designated topographic features (1) (1) (1) 

Pinnacle Trend area live bottoms (2) (2) (2) 

Eastern Gulf live bottoms (3) (3) (3) 

Benthic communities X(4) 

Water quality X X X 

Fisheries X X X 

Marine Mammals X(8) X X(8) X 

Sea Turtles X(8) X X(8) X 

Air quality X(9) 

Shipwreck sites (known or 

potential) 

 (7) 

Prehistoric archaeological sites (7) 

Vicinity of Offshore Location 

Essential fish habitat X X X(6) 

Marine and pelagic birds X X X 

Public health and safety (5) 

Coastal and Onshore 

Beaches X(6) X 

Wetlands X(6) 

Shore birds and coastal nesting 

birds 

 X(6) X 

Coastal wildlife refuges X 

Wilderness areas X 
2

Footnotes for Environmental Impact Analysis Matrix 

1) Activities that may affect a marine sanctuary or topographic feature. Specifically, if the well or platform site or 

any anchors will be on the seafloor within the: 

o 4-mile zone of the Flower Garden Banks, or the 3-mile zone of Stetson Bank; 

o 1000-m, 1-mile or 3-mile zone of any topographic feature (submarine bank) protected by the Topographic 

Features Stipulation attached to an OCS lease; 

o Essential Fish Habitat (EFH) criteria of 500 ft. from any no-activity zone; or 

o Proximity of any submarine bank (500 ft. buffer zone) with relief greater than 2 meters that is not protected 

by the Topographic Features Stipulation attached to an OCS lease. 

2) Activities with any bottom disturbance within an OCS lease block protected through the Live Bottom (Pinnacle 

Trend) Stipulation attached to an OCS lease. 

3) Activities within any Eastern Gulf OCS block where seafloor habitats are protected by the Live Bottom (LowRelief) Stipulation attached to an OCS lease. 

4) Activities on blocks designated by BOEMRE as being in water depths 300 meters or greater. 

5) Exploration or production activities where H2S concentrations greater than 500 ppm might be encountered. 

6) All activities that could result in an accidental spill of produced liquid hydrocarbons or diesel fuel that you 

determine would impact these environmental resources. If the proposed action is located a sufficient distance 

from a resource that no impact would occur, the EIA can note that in a sentence or two. 

7) All activities that involve seafloor disturbances, including anchor emplacements, in any OCS block designated 

by BOEMRE as having high-probability for the occurrence of shipwrecks or prehistoric sites, including such 

blocks that will be affected that are adjacent to the lease block in which your planned activity will occur. If the 

proposed activities are located a sufficient distance from a shipwreck or a prehistoric site that no impact would 

occur, the EIA can note that in a sentence or two. 

8) All activities that you determine might have an adverse effect on endangered or threatened marine mammals or 

sea turtles or their critical habitats. 

9) Production activities that involve transportation of produced fluids to shore using shuttle tankers or barges. 
3

(B) Analysis 

Site-Specific at Green Canyon Block 451 

Proposed operations consist of the drilling and temporary abandonment of three well locations. 

Operations will be conducted with a dynamically positioned semi-submersible. 

1. Designated Topographic Features 

Potential IPFs on topographic features include physical disturbances to the seafloor, effluents, 

and accidents. 

Physical disturbances to the seafloor: Green Canyon Block 451 is 34 miles from the closest 

designated Topographic Features Stipulation Block (Sweet Bank); therefore, no adverse impacts 

are expected. 

Effluents: Green Canyon Block 451 is 34 miles from the closest designated Topographic 

Features Stipulation Block (Sweet Bank); therefore, no adverse impacts are expected. 

Accidents: It is unlikely that an accidental surface or subsurface spill would occur from the 

proposed activities (refer to statistics in Item 5, Water Quality). Oil spills cause damage to 

benthic organisms only if the oil contacts the organisms. Oil from a surface spill can be driven 

into the water column; measurable amounts have been documented down to a 10 m depth. At 

this depth, the oil is found only at concentrations several orders of magnitude lower than the 

amount shown to have an effect on corals. Because the crests of topographic features in the 

Northern Gulf of Mexico are found below 10 m, no oil from a surface spill could reach their 

sessile biota. Oil from a subsurface spill is not applicable due to the distance of these blocks from 

a topographic area. The activities proposed in this plan will be covered by Woodside Energy 

(USA) Inc.’s Regional OSRP. 

There are no other IPFs (including emissions and wastes sent to shore for disposal) from the 

proposed activities, which could impact topographic features. 

2. Pinnacle Trend Area Live Bottoms 

Potential IPFs on pinnacle trend area live bottoms include physical disturbances to the seafloor, 

effluents, and accidents. 

Physical disturbances to the seafloor: Green Canyon Block 451 is 213 miles from the closest 

live bottom (pinnacle trend) area; therefore, no adverse impacts are expected. 
4

Effluents: Green Canyon Block 451 is 213 miles from the closest live bottom (pinnacle trend) 

area; therefore, no adverse impacts are expected. 

Accidents: It is unlikely that an accidental surface or subsurface spill would occur from the 

proposed activities (refer to statistics in Item 5, Water Quality). Oil spills have the potential to 

foul benthic communities and cause lethal and sublethal effects on live bottom organisms. Oil 

from a surface spill can be driven into the water column; measurable amounts have been 

documented down to a 10 m depth. At this depth, the oil is found only at concentrations several 

orders of magnitude lower than the amount shown to have an effect on marine organisms. Oil 

from a subsurface spill is not applicable due to the distance of these blocks from a live bottom 

(pinnacle trend) area. The activities proposed in this plan will be covered by Woodside Energy 

(USA) Inc.’s Regional OSRP. 

There are no other IPFs (including emissions and wastes sent to shore for disposal) from the 

proposed activities which could impact a live bottom (pinnacle trend) area. 

3. Eastern Gulf Live Bottoms 

Potential IPFs on Eastern Gulf live bottoms include physical disturbances to the seafloor, 

effluents, and accidents. 

Physical disturbances to the seafloor: Green Canyon Block 451 is not located in an area 

characterized by the existence of live bottoms, and this lease does not contain a Live-Bottom 

Stipulation requiring a photo documentation survey and survey report. 

Effluents: Green Canyon Block 451 is not located in an area characterized by the existence of 

live bottoms; therefore, no adverse impacts are expected. 

Accidents: It is unlikely that an accidental surface or subsurface spill would occur from the 

proposed activities (refer to statistics in Item 5, Water Quality). Oil spills cause damage to live 

bottom organisms only if the oil contacts the organisms. Oil from a surface spill can be driven 

into the water column; measurable amounts have been documented down to a 10 m depth. At 

this depth, the oil is found only at concentrations several orders of magnitude lower than the 

amount shown to have an effect on marine invertebrates. Oil from a subsurface spill is not 

applicable due to the distance of these blocks from a live bottom area. The activities proposed in 

this plan will be covered by Woodside Energy (USA) Inc.’s Regional OSRP. 

There are no other IPFs (including emissions and wastes sent to shore for disposal) from the 

proposed activities which could impact an Eastern Gulf live bottom area. 
5

4. Benthic Communities 

Green Canyon Block 451 is located in water depths 984 feet (300 meters) or greater. IPFs that 

could result in impacts to benthic communities from the proposed activities include physical 

disturbances to the seafloor. 

Physical disturbances to the seafloor: Green Canyon Block 451 is approximately 12 miles and 

13 miles, respectively, from a known benthic community site (Benthic Green Canyon Block 272 

and Green Canyon Block 233, respectively), listed in NTL 2009-G40. This Initial Exploration 

Plan submittal includes the required maps, analyses, and statement(s). The proposed activities 

will be conducted in accordance with NTL 2009-G40, which will ensure that features or areas 

that could support high-density benthic communities will not be impacted. 

There are no other IPFs (including emissions, effluents, wastes sent to shore for disposal, or 

accidents) from the proposed activities which could impact benthic communities. 

5. Water Quality 

IPFs that could result in water quality degradation from the proposed operations in Green 

Canyon Block 451 include disturbances to the seafloor, effluents and accidents. 

Physical disturbances to the seafloor: Bottom area disturbances resulting from the 

emplacement of drill rigs, the drilling of wells and the installation of platforms and pipelines 

would increase water-column turbidity and re-suspension of any accumulated pollutants, such as 

trace metals and excess nutrients. This would cause short-lived impacts on water quality 

conditions in the immediate vicinity of the emplacement operations. 

Effluents: Levels of contaminants in drilling muds and cuttings and produced water discharges, 

discharge-rate restrictions and monitoring and toxicity testing are regulated by the EPA NPDES 

permit, thereby eliminating many significant biological or ecological effects. Operational 

discharges are not expected to cause significant adverse impacts to water quality. 

Accidents: Oil spills have the potential to alter offshore water quality; however, it is unlikely 

that an accidental surface or subsurface spill would occur from the proposed activities. Between 

1980 and 2000, OCS operations produced 4.7 billion barrels of oil and spilled only 0.001 percent 

of this oil, or 1 bbl for every 81,000 bbl produced. The spill risk related to a diesel spill from 

drilling operations is even less. Between 1976 and 1985, (years for which data were collected), 

there were 80 reported diesel spills greater than one barrel associated with drilling activities. 

Considering that there were 11,944 wells drilled, this is a 0.7 percent probability of an 

occurrence. If a spill were to occur, the water quality of marine waters would be temporarily 

affected by the dissolved components and small oil droplets. Dispersion by currents and 

microbial degradation would remove the oil from the water column and dilute the constituents to 

background levels. Historically, changes in offshore water quality from oil spills have only been 

detected during the life of the spill and up to several months afterwards. Most of the components 
6

of oil are insoluble in water and therefore float. The activities proposed in this plan will be 

covered by Woodside Energy (USA) Inc.’s Regional Oil Spill Response Plan. 

There are no other IPFs (including emissions, physical disturbances to the seafloor, and wastes 

sent to shore for disposal) from the proposed activities which could cause impacts to water 

quality. 

6. Fisheries 

IPFs that could cause impacts to fisheries as a result of the proposed operations in Green Canyon 

Block 451 include physical disturbances to the seafloor, effluents and accidents. 

Physical disturbances to the seafloor: The emplacement of a structure or drilling rig results in 

minimal loss of bottom trawling area to commercial fishermen. Pipelines cause gear conflicts 

which result in losses of trawls and shrimp catch, business downtime and vessel damage. Most 

financial losses from gear conflicts are covered by the Fishermen’s Contingency Fund (FCF). 

The emplacement and removal of facilities are not expected to cause significant adverse impacts 

to fisheries. 

Effluents: Effluents such as drilling fluids and cuttings discharges contain components and 

properties which are detrimental to fishery resources. Moderate petroleum and metal 

contamination of sediments and the water column can occur out to several hundred meters downcurrent from the discharge point. Offshore discharges are expected to disperse and dilute to very 

near background levels in the water column or on the seafloor within 3,000 m of the discharge 

point, and are expected to have negligible effect on fisheries. 

Accidents: An accidental oil spill has the potential to cause some detrimental effects on 

fisheries; however, it is unlikely that such an event would occur from the proposed activities 

(refer to Item 5, Water Quality). The effects of oil on mobile adult finfish or shellfish would 

likely be sublethal and the extent of damage would be reduced to the capacity of adult fish and 

shellfish to avoid the spill, to metabolize hydrocarbons, and to excrete both metabolites and 

parent compounds. The activities proposed in this plan will be covered by Woodside Energy 

(USA) Inc.’s Regional OSRP. 

There are no IPFs from emissions, or wastes sent to shore for disposal from the proposed 

activities which could cause impacts to fisheries. 

7. Marine Mammals 

GulfCet II studies revealed that cetaceans of the continental shelf and shelf-edge were almost 

exclusively bottlenose dolphin and Atlantic spotted dolphin. Squid eaters, including dwarf and 

pygmy killer whale, Risso’s dolphin, rough-toothed dolphin, and Cuvier’s beaked whale, 

occurred most frequently along the upper slope in areas outside of anticyclones. IPFs that could 
7

cause impacts to marine mammals as a result of the proposed operations in Green Canyon Block 

451 include emissions, effluents, discarded trash and debris, and accidents. 

Emissions: Noises from drilling activities, support vessels and helicopters may elicit a startle 

reaction from marine mammals. This reaction may lead to disruption of marine mammals’ 

normal activities. Stress may make them more vulnerable to parasites, disease, environmental 

contaminants, and/or predation (Majors and Myrick, 1990). There is little conclusive evidence 

for long-term displacements and population trends for marine mammals relative to noise. 

Effluents: Drilling fluids and cuttings discharges contain components which may be detrimental 

to marine mammals. Most operational discharges are diluted and dispersed upon release. Any 

potential impact from drilling fluids would be indirect, either as a result of impacts on prey items 

or possibly through ingestion in the food chain (API, 1989). 

Discarded trash and debris: Both entanglement in, and ingestion of debris have caused the 

death or serious injury of marine mammals (Laist, 1997; MMC, 1999). The limited amount of 

marine debris, if any, resulting from the proposed activities is not expected to substantially harm 

marine mammals. Operators are prohibited from deliberately discharging debris as mandated by 

MARPOL-Annex V and the Marine Plastic Pollution Research and Control Act, and regulations 

imposed by various agencies including the United States Coast Guard (USCG) and the 

Environmental Protection Agency (EPA). 

Woodside Energy (USA) Inc. will operate in accordance with the regulations and also avoid 

accidental loss of solid waste items by maintaining waste management plans, manifesting trash 

sent to shore, and using special precautions such as covering outside trash bins to prevent 

accidental loss of solid waste. Special caution will be exercised when handling and disposing of 

small items and packaging materials, particularly those made of non-biodegradable, 

environmentally persistent materials such as plastic or glass. 

Informational placards will be posted on all vessels and facilities having sleeping or food 

preparation capabilities. All offshore personnel, including contractors and other support 

services-related personnel (e.g. helicopter pilots, vessel captains and boat crews) will be 

indoctrinated on waste procedures, and will view the video (or Microsoft PowerPoint 

presentation), “Think About It” (previously “All Washed Up: The Beach Litter Problem”). 

Thereafter, all personnel will view the marine trash and debris training video annually. Offshore 

personnel will also receive an explanation from Woodside Energy (USA) Inc. management or 

the designated lease operator management that emphasizes their commitment to waste 

management in accordance with NTL No. 2007-G03. 

Accidents: Collisions between support vessels and cetaceans would be unusual events, however 

should one occur, death or injury to marine mammals is possible. Contract vessel operators can 

avoid marine mammals and reduce potential deaths by maintaining a vigilant watch for marine 
8

mammals and maintaining a safe distance when they are sighted. Vessel crews should use a 

reference guide to help identify the twenty-eight species of whales and dolphins, and the single 

species of manatee that may be encountered in the Gulf of Mexico OCS. Vessel crews must 

report sightings of any injured or dead protected marine mammal species immediately, 

regardless of whether the injury or death is caused by their vessel, to the Marine Mammal and 

Sea Turtle Stranding Hotline at (888) 404-3922, the NMFS Southeast Regional Office at (727) 

824-5312, or the Louisiana Marine Mammal Stranding Network at (504) 235-3005. In addition, 

if the injury or death was caused by a collision with a contract vessel, the BOEMRE must be 

notified within 24 hours of the strike by email to protectedspecies@mms.gov. If the vessel is the 

responsible party, it is required to remain available to assist the respective salvage and stranding 

network as needed. 

Oil spills have the potential to cause sublethal oil-related injuries and spill-related deaths to 

marine mammals. However, it is unlikely that an accidental oil spill would occur from the 

proposed activities (refer to Item 5, Water Quality). Oil spill response activities may increase 

vessel traffic in the area, which could add to changes in cetacean behavior and/or distribution, 

thereby causing additional stress to the animals. The effect of oil dispersants on cetaceans is not 

known. The acute toxicity of oil dispersant chemicals included in Woodside Energy (USA) 

Inc.’s OSRP is considered to be low when compared with the constituents and fractions of crude 

oils and diesel products. The activities proposed in this plan will be covered by Woodside 

Energy (USA) Inc.’s OSRP. 

There are no other IPFs (including physical disturbances to the seafloor) from the proposed 

activities which could impact marine mammals. 

8. Sea Turtles 

IPFs that could cause impacts to sea turtles as a result of the proposed operations include 

emissions, effluents, discarded trash and debris, and accidents. GulfCet II studies sighted most 

loggerhead, Kemp’s ridley and leatherback sea turtles over shelf waters. Historically these 

species have been sighted up to the shelf’s edge. They appear to be more abundant east of the 

Mississippi River than they are west of the river (Fritts et al., 1983b; Lohoefener et al., 1990). 

Deep waters may be used by all species as a transitory habitat. 

Emissions: Noise from drilling activities, support vessels, and helicopters may elicit a startle 

reaction from sea turtles, but this is a temporary disturbance. 

Effluents: Drilling fluids and cuttings discharges are not known to be lethal to sea turtles. Most 

operational discharges are diluted and dispersed upon release. Any potential impact from 

drilling fluids would be indirect, either as a result of impacts on prey items or possibly through 

ingestion in the food chain (API, 1989). 
9

Discarded trash and debris: Both entanglement in, and ingestion of, debris have caused the death 

or serious injury of sea turtles (Balazs, 1985). The limited amount of marine debris, if any, 

resulting from the proposed activities is not expected to substantially harm sea turtles. Operators 

are prohibited from deliberately discharging debris as mandated by MARPOL-Annex V and the 

Marine Plastic Pollution Research and Control Act, and regulations imposed by various agencies 

including the United States Coast Guard (USCG) and the Environmental Protection Agency 

(EPA). Woodside Energy (USA) Inc. will operate in accordance with the regulations and also 

avoid accidental loss of solid waste items by maintaining waste management plans, manifesting 

trash sent to shore, and using special precautions such as covering outside trash bins to prevent 

accidental loss of solid waste. Special caution will be exercised when handling and disposing of 

small items and packaging materials, particularly those made of non-biodegradable, 

environmentally persistent materials such as plastic or glass. 

Informational placards will be posted on all vessels and facilities having sleeping or food 

preparation capabilities. All offshore personnel, including contractors and other support 

services-related personnel (e.g. helicopter pilots, vessel captains and boat crews) will be 

indoctrinated on waste procedures, and will view the video (or Microsoft PowerPoint 

presentation), “Think About It” (previously “All Washed Up: The Beach Litter Problem”). 

Thereafter, all personnel will view the marine trash and debris training video annually. Offshore 

personnel will also receive an explanation from Woodside Energy (USA) Inc. management or 

the designated lease operator management that emphasizes their commitment to waste 

management in accordance with NTL No. 2007-G03. 

Accidents: Collisions between support vessels and sea turtles would be unusual events, however 

should one occur, death or injury to sea turtles is possible. Contract vessel operators can avoid 

sea turtles and reduce potential deaths by maintaining a vigilant watch for sea turtles and 

maintaining a safe distance when they are sighted. Vessel crews should use a reference guide to 

help identify the five species of sea turtles that may be encountered in the Gulf of Mexico OCS. 

Vessel crews must report sightings of any injured or dead protected sea turtle species 

immediately, regardless of whether the injury or death is caused by their vessel, to the Marine 

Mammal and Sea Turtle Stranding Hotline at (888) 404-3922, the NMFS Southeast Regional 

Office at (727) 824-5312, or the Louisiana Marine Mammal Stranding Network at (504) 235-

3005. In addition, if the injury or death was caused by a collision with a contract vessel, the 

BOEMRE must be notified within 24 hours of the strike by email to protectedspecies@mms.gov. 

If the vessel is the responsible party, it is required to remain available to assist the respective 

salvage and stranding network as needed. 

All sea turtle species and their life stages are vulnerable to the harmful effects of oil through 

direct contact or by fouling of their food. Exposure to oil can be fatal, particularly to juveniles 

and hatchlings. However, it is unlikely that an accidental oil spill would occur from the proposed 

activities (refer to Item 5, Water Quality). Oil spill response activities may increase vessel traffic 

in the area, which could add to the possibility of collisions with sea turtles. The activities 

proposed in this plan will be covered by Woodside Energy (USA) Inc.’s Regional Oil Spill 

Response Plan. 
10

There are no other IPFs (including physical disturbances to the seafloor) from the proposed 

activities which could impact sea turtles. 

9. Air Quality 

The projected air emissions identified in Appendix G are not expected to affect the OCS air 

quality primarily due to distance to the shore or to any Prevention of Significant Deterioration 

Class I air quality area such as the Breton Wilderness Area. Green Canyon Block 451 is beyond 

the 200 kilometer (124 mile) buffer for the Breton Wilderness Area and is 109 miles from the 

coastline. Therefore, no special mitigation, monitoring, or reporting requirements apply with 

respect to air emissions. 

Accidents and blowouts can release hydrocarbons or chemicals, which could cause the emission 

of air pollutants. However, these releases would not impact onshore air quality because of the 

prevailing atmospheric conditions, emission height, emission rates, and the distance of Green 

Canyon Block 451 from the coastline. There are no other IPFs (including effluents, physical 

disturbances to the seafloor, wastes sent to shore for treatment or disposal) from the proposed 

activities which could impact air quality. 

10. Shipwreck Sites (known or potential) 

IPFs that could impact known or unknown shipwreck sites as a result of the proposed operations 

in Green Canyon Block 451 include disturbances to the seafloor. Green Canyon Block 451 is 

not located in or adjacent to an OCS block designated by BOEMRE as having a high probability 

for occurrence of shipwrecks. Woodside Energy (USA) Inc. will report to BOEMRE the 

discovery of any evidence of a shipwreck and make every reasonable effort to preserve and 

protect that cultural resource. There are no other IPFs (including emissions, effluents, wastes sent 

to shore for treatment or disposal, or accidents) from the proposed activities which could impact 

shipwreck sites. 

11. Prehistoric Archaeological Sites 

IPFs which could impact prehistoric archaeological sites as a result of the proposed operations in 

Green Canyon Block 451 include disturbances to the seafloor (structure emplacement) and 

accidents (oil spill). Green Canyon Block 451 is located outside the Archaeological Prehistoric 

high probability line. Woodside Energy (USA) Inc. will report to BOEMRE the discovery of any 

object of prehistoric archaeological significance and make every reasonable effort to preserve 

and protect that cultural resource. 

Accidents: An accidental oil spill has the potential to cause some detrimental effects to 

prehistoric archaeological sites if the release were to occur subsea. However, it is unlikely that an 

accidental oil spill would occur from the proposed activities (refer to Item 5, Water Quality). 

The activities proposed in this plan will be covered by Woodside Energy (USA) Inc.’s Regional 

Oil Spill Response Plan. 
11

There are no other IPFs (including emissions, effluents, wastes sent to shore for treatment or 

disposal) from the proposed activities which could impact prehistoric archaeological sites. 

Vicinity of Offshore Location 

1. Essential Fish Habitat (EFH) 

IPFs that could cause impacts to EFH as a result of the proposed operations in Green Canyon 

Block 451 include physical disturbances to the seafloor, effluents and accidents. EFH includes 

all estuarine and marine waters and substrates in the Gulf of Mexico. 

Physical disturbances to the seafloor: The Live Bottom Low Relief Stipulation, the Live 

Bottom (Pinnacle Trend) Stipulation, and the Eastern Gulf Pinnacle Trend Stipulation would 

prevent most of the potential impacts on live-bottom communities and EFH from bottom 

disturbing activities (e.g., anchoring, structure emplacement and removal). 

Effluents: The Live Bottom Low Relief Stipulation, the Live Bottom (Pinnacle Trend) 

Stipulation, and the Eastern Gulf Pinnacle Trend Stipulation would prevent most of the potential 

impacts on live-bottom communities and EFH from operational waste discharges. Levels of 

contaminants in drilling muds and cuttings and produced-water discharges, discharge-rate 

restrictions, and monitoring and toxicity testing are regulated by the EPA NPDES permit, 

thereby eliminating many significant biological or ecological effects. Operational discharges are 

not expected to cause significant adverse impacts to EFH. 

Accidents: An accidental oil spill has the potential to cause some detrimental effects on EFH. 

Oil spills that contact coastal bays and estuaries, as well as OCS waters when pelagic eggs and 

larvae are present, have the greatest potential to affect fisheries. However, it is unlikely that an 

oil spill would occur from the proposed activities (refer to Item 5, Water Quality). The activities 

proposed in this plan will be covered by Woodside Energy (USA) Inc.’s Regional OSRP. 

There are no other IPFs (including emissions, or wastes sent to shore for treatment or disposal) 

from the proposed activities which could impact essential fish habitat. 

2. Marine and Pelagic Birds 

IPFs that could impact marine birds as a result of the proposed activities include air emissions, 

accidental oil spills, and discarded trash and debris from vessels and the facilities. 

Emissions: Emissions of pollutants into the atmosphere from these activities are far below 

concentrations which could harm coastal and marine birds. 
12

Accidents: An oil spill would cause localized, low-level petroleum hydrocarbon contamination. 

However, it is unlikely that an oil spill would occur from the proposed activities (refer to Item 5, 

Water Quality). Marine and pelagic birds feeding at the spill location may experience chronic, 

nonfatal, physiological stress. It is expected that few, if any, coastal and marine birds would 

actually be affected to that extent. The activities proposed in this plan will be covered by 

Woodside Energy (USA) Inc.’s Regional OSRP. 

Discarded trash and debris: Marine and pelagic birds could become entangled and snared in 

discarded trash and debris, or ingest small plastic debris, which can cause permanent injuries and 

death. Operators are prohibited from deliberately discharging debris as mandated by MARPOLAnnex V and the Marine Plastic Pollution Research and Control Act, and regulations imposed by 

various agencies including the United States Coast Guard (USCG) and the Environmental 

Protection Agency (EPA). Woodside Energy (USA) Inc. will operate in accordance with the 

regulations and also avoid accidental loss of solid waste items by maintaining waste management 

plans, manifesting trash sent to shore, and using special precautions such as covering outside 

trash bins to prevent accidental loss of solid waste. Special caution will be exercised when 

handling and disposing of small items and packaging materials, particularly those made of nonbiodegradable, environmentally persistent materials such as plastic or glass. Informational 

placards will be posted on all vessels and facilities having sleeping or food preparation 

capabilities. All offshore personnel, including contractors and other support services-related 

personnel (e.g. helicopter pilots, vessel captains and boat crews) will be indoctrinated on waste 

procedures, and will view the video (or Microsoft PowerPoint presentation), “Think About It” 

(previously “All Washed Up: The Beach Litter Problem”). Thereafter, all personnel will view 

the marine trash and debris training video annually. Offshore personnel will also receive an 

explanation from Woodside Energy (USA) Inc. management or the designated lease operator 

management that emphasizes their commitment to waste management in accordance with NTL 

No. 2007-G03. Debris, if any, from these proposed activities will seldom interact with marine 

and pelagic birds; therefore, the effects will be negligible. 

There are no other IPFs (including effluents, physical disturbances to the seafloor, or wastes sent 

to shore for treatment or disposal) from the proposed activities which could impact marine and 

pelagic birds. 

3. Public Health and Safety Due to Accidents. 

There are no IPFs (emissions, effluents, physical disturbances to the seafloor, wastes sent to 

shore for treatment or disposal or accidents, including an accidental H2S releases) from the 

proposed activities which could cause impacts to public health and safety. In accordance with 

NTL No.’s 2008-G04, 2009-G27, and 2009-G31, sufficient information is included in Appendix 

C to justify our request that our proposed activities be classified by BOEMRE as H2S absent. 

Coastal and Onshore 
13

1. Beaches 

IPFs from the proposed activities that could cause impacts to beaches include accidents (oil 

spills) and discarded trash and debris. 

Accidents: Oil spills contacting beaches would have impacts on the use of recreational beaches 

and associated resources. Due to the distance from shore (109 miles) and the response 

capabilities that would be implemented, no significant adverse impacts are expected. The 

activities proposed in this plan will be covered by Woodside Energy (USA) Inc.’s Regional 

OSRP. 

Discarded trash and debris: Trash on the beach is recognized as a major threat to the 

enjoyment and use of beaches. There will only be a limited amount of marine debris, if any, 

resulting from the proposed activities. Operators are prohibited from deliberately discharging 

debris as mandated by MARPOL-Annex V and the Marine Plastic Pollution Research and 

Control Act, and regulations imposed by various agencies including the United States Coast 

Guard (USCG) and the Environmental Protection Agency (EPA). Woodside Energy (USA) Inc. 

will operate in accordance with the regulations and also avoid accidental loss of solid waste 

items by maintaining waste management plans, manifesting trash sent to shore, and using special 

precautions such as covering outside trash bins to prevent accidental loss of solid waste. Special 

caution will be exercised when handling and disposing of small items and packaging materials, 

particularly those made of non-biodegradable, environmentally persistent materials such as 

plastic or glass. 

Informational placards will be posted on all vessels and facilities having sleeping or food 

preparation capabilities. All offshore personnel, including contractors and other support 

services-related personnel (e.g. helicopter pilots, vessel captains and boat crews) will be 

indoctrinated on waste procedures, and will view the video (or Microsoft PowerPoint 

presentation), “Think About It” (previously “All Washed Up: The Beach Litter Problem”). 

Thereafter, all personnel will view the marine trash and debris training video annually. Offshore 

personnel will also receive an explanation from Woodside Energy (USA) Inc. management or 

the designated lease operator management that emphasizes their commitment to waste 

management in accordance with NTL No. 2007-G03. 

There are no other IPFs (emissions, effluents, physical disturbances to the seafloor, or wastes 

sent to shore for treatment or disposal) from the proposed activities which could impact beaches. 

2. Wetlands 

Accidents: Oil spills could cause impacts to wetlands, however, it is unlikely that an oil spill 

would occur from the proposed activities (refer to Item 5, Water Quality). Due to the distance 

from shore (109 miles) and the response capabilities that would be implemented, no impacts are 

expected. The activities proposed in this plan will be covered by Woodside Energy (USA) Inc.’s 

Regional OSRP. 
14

There are no other IPFs (emissions, effluents, physical disturbances to the seafloor, or wastes 

sent to shore for treatment or disposal) from the proposed activities which could impact 

wetlands. 

3. Shore Birds and Coastal Nesting Birds 

Accidents: Oil spills could cause impacts to shore birds and coastal nesting birds. However, it is 

unlikely that an oil spill would occur from the proposed activities (refer to Item 5, Water 

Quality). Given the distance from shore (109 miles) and the response capabilities that would be 

implemented, no impacts are expected. The activities proposed in this plan will be covered by 

Woodside Energy (USA) Inc.’s Regional OSRP. 

Discarded trash and debris: Coastal and marine birds are highly susceptible to entanglement 

in floating, submerged, and beached marine debris: specifically plastics. Operators are prohibited 

from deliberately discharging debris as mandated by MARPOL-Annex V and the Marine Plastic 

Pollution Research and Control Act, and regulations imposed by various agencies including the 

United States Coast Guard (USCG) and the Environmental Protection Agency (EPA). Woodside 

Energy (USA) Inc. will operate in accordance with the regulations and also avoid accidental loss 

of solid waste items by maintaining waste management plans, manifesting trash sent to shore, 

and using special precautions such as covering outside trash bins to prevent accidental loss of 

solid waste. Special caution will be exercised when handling and disposing of small items and 

packaging materials, particularly those made of non-biodegradable, environmentally persistent 

materials such as plastic or glass. 

 

Informational placards will be posted on vessels and every facility that has sleeping or food 

preparation capabilities. All offshore personnel, including contractors and other support 

services-related personnel (e.g. helicopter pilots, vessel captains and boat crews) will be 

indoctrinated on waste procedures, and will view the video (or Microsoft PowerPoint 

presentation), “Think About It” (previously “All Washed Up: The Beach Litter Problem”). 

Thereafter, all personnel will view the marine trash and debris training video annually. Offshore 

personnel will also receive an explanation from Woodside Energy (USA) Inc. management or 

the designated lease operator management that emphasizes their commitment to waste 

management in accordance with NTL No. 2007-G03. 

There are no other IPFs (emissions, effluents, physical disturbances to the seafloor, or wastes 

sent to shore for treatment or disposal) from the proposed activities that could cause impacts to 

shore birds and coastal nesting birds. 

4. Coastal Wildlife Refuges 

Accidents: An accidental oil spill from the proposed activities could cause impacts to coastal 

wildlife refuges. However, it is unlikely that an oil spill would occur from the proposed activities 

(refer to Item 5, Water Quality). Due to the distance from shore (109 miles) and the response 
15

capabilities that would be implemented, no impacts are expected. The activities proposed in this 

plan will be covered by Woodside Energy (USA) Inc.’s Regional OSRP. 

There are no other IPFs (emissions, effluents, physical disturbances to the seafloor, or wastes 

sent to shore for treatment or disposal) from the proposed activities that could cause impacts to 

coastal wildlife refuges. 

5. Wilderness Areas 

An accidental oil spill from the proposed activities could cause impacts to wilderness areas. 

However, it is unlikely that an oil spill would occur from the proposed activities (refer to Item 5, 

Water Quality). Due to the distance from the Breton Wilderness Area (215 miles) and the 

response capabilities that would be implemented, no significant adverse impacts are expected. 

The activities proposed in this plan will be covered by Woodside Energy (USA) Inc.’s Regional 

OSRP.

6. Other Environmental Resources Identified 

(C) Impacts on your proposed activities. 

The site–specific environmental conditions have been taken into account for the proposed 

activities. No impacts are expected on the proposed activities from site-specific environmental 

conditions. 

(D) Environmental Hazards 

During the hurricane season, June through November, the Gulf of Mexico is impacted by an 

average of ten tropical storms (39-73 mph winds), of which six become hurricanes ( > 74 mph 

winds). Due to its location in the gulf, Green Canyon Block 451 may experience hurricane and 

tropical storm force winds, and related sea currents. These factors can adversely impact the 

integrity of the operations covered by this plan. A significant storm may present physical hazards 

to operators and vessels, damage exploration or production equipment, or result in the release of 

hazardous materials (including hydrocarbons). Additionally, the displacement of equipment may 

disrupt the local benthic habitat and pose a threat to local species. 

The following preventative measures included in this plan may be implemented to mitigate these 

impacts: 

Drilling & completion 

a. Secure well locations 

b. Secure DP 

c. Evacuate personnel 

Drilling activities will be conducted in accordance with NTL No.’s 2008-G09 and 2009-G10. 
16

(E) Alternatives 

No alternatives to the proposed activities were considered to reduce environmental impacts. 

(F) Mitigation Measures 

No mitigation measures other than those required by regulation will be employed to avoid, 

diminish, or eliminate potential impacts on environmental resources. 

(G) Consultation 

No agencies or persons were consulted regarding potential impacts associated with the proposed 

activities. Therefore, a list of such entities has not been provided. 

(H) Preparer(s) 

Bridget O'Farrell-Villarreal 

J. Connor Consulting, Inc. 

16225 Park Ten Place, Suite 700 

Houston, TX 77084 

(281) 578-3388 

Bridget.O’Farrell@jccteam.com 

(I) References 

Authors: 

• American Petroleum Institute (API). 1989. Effects of offshore petroleum operations on cold 

water marine mammals: a literature review. Washington, DC: American Petroleum 

Institute. 385 pp. 

• Fritts et al., 1983b; Lohoefener et al., 1990. Decline of the Sea Turtles: Causes and 

Prevention. Commission on Life Sciences. Earth and Life Sciences. National Academy 

Press, 1990. 

• Laist, D.W. 1997. Impacts of marine debris: entanglement of marine life in marine debris 

including a comprehensive list of species with entanglement and ingestion records. In: 

Coe, J.M. and D.B. Rogers, eds. Marine debris: sources, impacts, and solutions. New 

York, NY: Springer-Verlag. Pp. 99-139 

• Majors, A.P. and A.C. Myrick, Jr. 1990. Effects of noise on animals: implications for 

dolphins exposed to seal bombs in the eastern tropical Pacific purse-seine fishery–an 

annotated bibliography. NOAA Administrative Report LJ-90-06. 

• Marine Mammal Commission. 1999. Annual report to Congress – 1998 
17

Although not cited, the following were utilized in preparing this EIA: 

• Balazs, G.H. 1985. Impact of ocean debris on marine turtles: entanglement and ingestion. In: 

Shomura, R.S. and H.O. Yoshida, eds. Proceedings, Workshop on the Fate and Impact of 

Marine Debris, 26-29 November 1984, Honolulu, HI. U.S. Dept. of Commerce. NOAA 

Tech. Memo. NOAA-TM-NMFS-SWFC-54. Pp 387-429. 

• Burke, C.J. and J.A. Veil. 1995. Potential benefits from regulatory consideration of synthetic 

drilling muds. Environmental Assessment Division, Argonne National Laboratory, 

ANL/EAD/TM-43 

• Daly, J.M. 1997. Controlling the discharge of synthetic-based drilling fluid contaminated 

cuttings in waters of the United States. U.S. Environmental Protection Agency, Office of 

Water. Work Plan, June 24, 1997. 

• Hansen, D.J. 198l. The relative sensitivity of seabird populations in Alaska to oil pollution. 

U.S. Dept. of the Interior, Bureau of Land Management, Alaska OCS Region, Anchorage. 

BLM-YK-ES-81-006-1792. 

• Piatt, J.F., C.J. Lensink, W. Butler, M. Kendziorek, and D.R. Nysewander. 1990. Immediate 

impact of the Exxon Valdez oil spill on marine birds. The Auk. 107 (2): 387-397 

• Vauk , G., E. Hartwig, B. Reineking, and E. Vauk-Hentzelt. 1989. Losses of seabirds by oil 

pollution at the German North Sea coast. Topics in Marine Biology. Ros, J.D, ed. Scient. 

Mar. 53 (2-3): 749-754 

• Vermeer, K. and R. Vermeer, 1975 Oil threat to birds on the Canadian west coast. The 

Canadian Field-Naturalist. 89:278-298. 

• Hazard Surveys 

• BOEMRE EIS’s: 

o GOM Deepwater Operations and Activities. Environmental Assessment. BOEMRE 

2000-001 

o GOM Central and Western Planning Areas Sales 166 and 168 Final Environmental 

Impact Statement. BOEMRE 96-0059 
EIA Summary

As per 30 CFR 250.227(b), “Your EIA must describe those resources, conditions, and 

activities listed below that could be affected by your exploration activities, or that could 

affect the construction and operation of facilities or structures, or the activities proposed 

in your EP”. 

Meteorology, oceanography, geology, and shallow geological or man-made 

hazards. 

Meteorology, oceanography, geology, and shallow geological or man-made hazards 

that could be affected by the proposed operations are addressed in the EIA and GEMS 

shallow hazards survey. 

Air and water quality. 

Air and water quality that could be affected by the proposed operations are addressed in 

the EIA. 

Benthic communities, marine mammals, sea turtles, coastal and marine birds, fish 

and shellfish, and plant life. 

The benthic communities, marine mammals, sea turtles, coastal and marine birds, fish 

and shellfish, and plant life that could be affected by the proposed operations are 

addressed in the EIA and in the threatened and endangered species section of this EP. 

Threatened or endangered species and their critical habitat as defined by the 

Endangered Species Act of 1973. 

The threatened or endangered species and their critical habitats that could be affected 

by the proposed operations are addressed in the EIA and in the threatened and 

endangered species section of this EP. 

Sensitive biological resources or habitats such as essential fish habitat, refuges, 

preserves, special management areas identified in coastal management programs, 

sanctuaries, rookeries, and calving grounds. 

Sensitive biological resources or habitats such as essential fish habitat, refuges, 

preserves, special management areas identified in coastal management programs, 

sanctuaries, rookeries, and calving grounds that could be affected by the proposed 

operations are addressed in the EIA. 

Archaeological resources. 

Archaeological resources that could be affected by the proposed operations are 

addressed in the EIA and GEMS shallow hazards survey 
Socioeconomic resources including employment, existing offshore and coastal 

infrastructure (including major sources of supplies, services, energy, and water), 

land use, subsistence resources and harvest practices, recreational and 

commercial fishing (including typical fishing seasons, location, and type), 

minority and lower income groups, and coastal zone management programs. 

Socioeconomic resources including employment, existing offshore and coastal 

infrastructure (including major sources of supplies, services, energy, and water), land 

use, subsistence resources and harvest practices, recreational and commercial fishing 

(including typical fishing seasons, location, and type), minority and lower income groups, 

and coastal zone management programs that could be affected by the proposed 

operations are addressed in the EIA. 

Coastal and marine uses such as military activities, shipping, and mineral 

exploration or development. 

Coastal and marine uses such as military activities, shipping, and mineral exploration or 

development that could be affected by the proposed operations are addressed in the EP. 

Other resources conditions, and activities identified by the Regional Supervisor. 

At this time Woodside knows of no other resources conditions, and activities identified by 

the Regional Supervisor that would pertain to the proposed operations of this EP. 
Attachment N 

Oil Spill Response Discussion 

OSRP Certification 
SPILL RESPONSE DISCUSSION 

For the purpose of NEPA and Coastal Zone Management Act analysis, the largest spill volume 

originating from the proposed activity would be a well blowout during drilling operations, estimated to 

be 159,951 barrels of crude oil with an API gravity of 29°. 

Land Segment and Resource Identification

Trajectories of a spill and the probability of it impacting a land segment have been projected utilizing 

information in the BOEM Oil Spill Risk Analysis Model (OSRAM) for the Central and Western Gulf of 

Mexico available on the BOEM website. The results are shown in Figure 1. The BOEM OSRAM 

identifies a 7% probability of impact to the shorelines of Cameron Parish, Louisiana within 30 days. 

Cameron Parish includes the east side of Sabine Lake, Sabine National Wildlife Refuge, Calcasieu 

Lake, Lacassine National Wildlife Refuge (inland) and Grand Lake. Cameron Parish also includes 

the area along the coastline from Sabine Pass to Big Constance Lake in Rockefeller Wildlife Refuge. 

This region is composed of open public beaches, marshlands and swamps. It serves as a habitat for 

numerous birds, finfish and other animals, including several rare, threatened and endangered 

species. 

Response

Woodside Energy (USA) Inc. will make every effort to respond to the Worst Case Discharge as 

effectively as practicable. A description of the response equipment available to contain and recover 

the Worst Case Discharge is shown in Figure 2. 

Using the estimated chemical and physical characteristics of crude oil, an ADIOS weathering model 

was run on a similar product from the ADIOS oil database. The results indicate 16% or 25,592 

barrels of crude oil would be evaporated/dispersed within 24 hours, with 134,359 barrels remaining. 

Spill Response GC 451 Barrels of Oil 

WCD Volume 159,951 

Less 16% natural evaporation/dispersion 25,592 

Remaining volume 134,359 

Oil addressed by aerial dispersants 7,540 

Oil addressed by in-situ burning 6,717 

Figure 2 outlines equipment, personnel, materials and support vessels as well as temporary storage 

equipment available to respond to a spill of 159,951 barrels. The list estimates individual times 

needed for procurement, load out, travel time to the site and deployment. Figure 2 also indicates 

how operations will be supported. Estimated time for surface containment is 5 days.

If aerial dispersants are utilized, 8 sorties (9,600 gallons) from two of the DC-3 aircrafts and 4 sorties 

(8,000 gallons) from the Basler aircraft should disperse approximately 7,540 barrels of product. If the 

conditions are favorable for in-situ burning, the proper approvals have been obtained and the proper 

planning is in place, in-situ burning of oil may be attempted. Using estimates based on the 

Deepwater Horizon spill of 2010, up to 5% or 6,717 barrels of the total daily Worst Case Discharge 
volume could be burned. Slick containment boom would be immediately called out and on-scene as 

soon as possible. Offshore response strategies may include attempting to skim utilizing the HOSS 

Barge and eight Fast Response Units from CGA’s inventory. From NRCC, offshore response 

strategies may include attempting to skim utilizing the Marco Class XI AB skimmers on the OSRB 

Defender, the OSRV Admiral, two rope mop skimmers, three Vikoma Cascade skimmers and one 

additional Marco Class XI AB skimmer. Total derated skimming capacity of CGA and NRCC 

equipment is 165,512 barrels. Temporary storage associated with skimming equipment equals 

23,100 barrels. For additional temporary storage, portable barge sets and bladders totaling 4,584 

barrels may be deployed. If additional storage is needed, one 47,000 barrel storage barge, one 

25,000 barrel storage barge, one 23,000 barrel storage barge, and three 20,000 barrel storage 

barges may be mobilized and centrally located to provide temporary storage allowing the skimmers 

to stay in the area of operations as much as possible. Safety is first priority. Air monitoring will 

be accomplished and operations deemed safe prior to any containment/skimming attempts. 

If the spill went unabated, shoreline impact in Cameron Parish, Louisiana would depend upon 

existing environmental conditions. Shoreline protection would include the use of CGA’s near shore 

and shallow water skimmers with a totaled derated skimming capacity of 33,253 barrels. Temporary 

storage associated with skimming equipment equals 1,512 barrels. If additional storage is needed, 

two 23,000 barrel storage barges may be mobilized and centrally located to provide temporary 

storage allowing the skimmers to stay in the area of operations as much as possible. Onshore 

response may include the deployment of shoreline boom on beach areas, or protection and sorbent 

boom on vegetated areas. A Master Service Contract with Oil Mop will ensure access to 30,000 feet 

of 18” shoreline protection boom. Figure 2 outlines individual times needed for procurement, load 

out, travel time to the site and deployment. Strategies would be based upon surveillance and real 

time trajectories that depict areas of potential impact given actual sea and weather conditions. The 

State of Louisiana Initial Oil Spill Response Plan for Cameron Parish and Unified Command would 

be consulted to ensure that environmental and special economic resources would be correctly 

identified and prioritized to ensure optimal protection. Shoreline protection strategies depict the 

protection response modes applicable for oil spill clean-up operations. The State of Louisiana Initial 

Oil Spill Response Plan provides detailed shoreline protection strategies for this area, and it 

describes necessary action to keep the oil spill from entering Louisiana’s coastal wetlands, based on 

the assumption that removal of the released oil will be much easier and less damaging to fragile 

coastal ecosystems if done in the open waters of the Gulf of Mexico. Supervisory personnel have the 

option to modify the deployment and operation of equipment allowing a more effective response to 

site-specific circumstances. Woodside Energy (USA) Inc.’s contract Spill Management Team holds a 

copy of the State of Louisiana Initial Oil Spill Response Plan. 
Initial Response Considerations 

Actual actions taken during an oil spill response will be based on many factors to include but not be 

limited to: 

• Weather 

• Equipment and materials availability 

• Ocean currents and tides 

• Location of the spill 

• Product spilled 

• Amount spilled 

• Environmental risk assessments 

• Trajectory and product analysis 

• Well status, i.e., shut in or continual release 

Woodside Energy (USA) Inc. will take action to provide a safe, aggressive response to contain and 

recover as much of the spilled oil as quickly as it is safe to do so. In an effort to protect the environment, 

response actions will be designed to provide an “in-depth” protection strategy meant to recover as much 

oil as possible as far from environmentally sensitive areas as possible. Safety will take precedence over 

all other considerations during these operations. Surface containment time frame is approximately 5 days.

Upon notification of a spill, the following actions will be taken: 

• Information will be confirmed 

• An assessment will be made and initial objectives set 

• OSROs and appropriate agencies will be notified 

• ICS 201, Initial Report Form completed 

• Initial Safety plan will be written and published 

• Unified Command will be established 

o Overall safety plan developed to reflect the operational situation and coordinated objectives 

o Areas of responsibility established for Source Control and each surface operational site 

o On-site command and control established 

Offshore Response Actions 

Equipment Deployment

Surveillance 

• Surveillance Aircraft: within two hours of QI notification, or at first light

• Provide trained observer to provide on site status reports 

• Provide command and control platform at the site if needed 

• Continual surveillance of oil movement by remote sensing systems, aerial photography and visual 

confirmation 

• Continual monitoring of vessel assets using vessel monitoring systems 

Dispersant application assets 

• Put ASI on standby 

• With the FOSC, conduct analysis to determine appropriateness of dispersant application (refer to 

Section 18) 

• Gain FOSC approval for use of dispersants on the surface 

• Deploy aircraft in accordance with a plan developed for the actual situation 

• Coordinate movement of dispersants, aircraft, and support equipment and personnel 

• Confirm dispersant availability for current and long range operations 

• Start ordering dispersant stocks required for expected operations 
Containment boom 

• Call out early and expedite deployment to be on scene ASAP 

• Ensure boom handling and mooring equipment is deployed with boom 

• Provide continuing reports to vessels to expedite their arrival at sites that will provide for their 

most effective containment 

• Use Vessels of Opportunity (VOO) to deploy and maintain boom 

Dedicated off-shore skimming systems 

General 

• Deployed to the highest concentration of oil 

• Assets deployed at safe distance from aerial dispersant and in-situ burn operations 

CGA HOSS Barge 

• Use in areas with heaviest oil concentrations 

• Consider for use in areas of known debris (seaweed, and other floating materials) 

CGA FRUs 

• To the area of the thickest oil 

• Use as far off-shore as allowed 

Storage Vessels 

• Establish availability of CGA contracted assets (See Appendix E) 

• Early call out (to allow for tug boat acquisition and deployment speeds) 

• Phase mobilization to allow storage vessels to arrive at the same time as skimming systems 

• Position as closely as possible to skimming assets to minimize offloading time 

Vessels of Opportunity (VOO) 

• Use Woodside Energy (USA) Inc.’s contracted resources as applicable 

• Industry vessels are usually best for deployment of Vessel of Opportunity Skimming Systems 

(VOSS) 

• Acquire additional resources as needed 

• Consider use of local assets, i.e. fishing and pleasure craft 

• Expect mission specific and safety training to be required 

• Plan with the US Coast Guard for vessel inspections 

In-situ Burn assets 

• Determine appropriateness of in-situ burn operation in coordination with the FOSC and affected 

SOSC 

• Determine availability of fire boom and selected ignition systems 

• Start ordering fire boom stocks required for expected operations 

• Contact boom manufacturer to provide training if required 

• Determine assets to perform on water operation 

• Build operations into safety plan 

• Conduct operations in accordance with an approved plan 
Near Shore Response Actions 

Timing 

• Put near shore assets on standby and deployment in accordance with planning based on the 

actual situation, actual trajectories and oil budgets 

• VOO identification and training in advance of spill nearing shoreline if possible 

• Outfitting of VOOs for specific missions 

• Deployment of assets based on actual movement of oil 

Considerations 

• Water depth, vessel draft 

• Shoreline gradient 

• State of the oil 

• Use of VOOs 

• Distance of surf zone from shoreline 

Equipment Deployment 

Surveillance 

• Provide trained observer to direct skimming operations 

• Continual surveillance of oil movement by remote sensing systems, aerial photography and visual 

confirmation 

• Continual monitoring of vessel assets 

Dispersant Use 

• Generally will not be approved within 3 miles of shore or with less than 10 meters of water depth 

• Approval would be at Regional Response Team level (Region 6) 

Vessel Deployment 

Dedicated Near Shore skimming systems 

• FRVs 

• Egmopol and Marco SWS 

• Operate with aerial spotter directing systems to observed oil slicks 

VOO 

• Use Woodside Energy (USA) Inc.’s contracted resources as applicable 

• Industry vessel are usually best for deployment of Vessel of Opportunity Skimming Systems 

(VOSS) 

• Acquire additional resources as needed 

• Consider use of local assets, i.e. fishing and pleasure craft 

• Expect mission specific and safety training to be required 

• Plan with the US Coast Guard for vessel inspections 

• Operate with aerial spotter directing systems to oil patches 
Shoreline Protection Operations 

Response Planning Considerations 

• Environmental risk assessments (ERA) to determine priorities for area protection 

• Time to acquire personnel and equipment and their availability 

• Previous contingency planning contained in the appropriate Area Contingency Plan, and 

currently (Feb 2011) for Louisiana, The State of Louisiana Initial Oil Spill Response Plan, 

Deep Water Horizon, dated 2 May 2010 (La. OSRP)

Actions 

Placement of boom 

• Position boom in accordance with the ERA based on the actual situation or the appropriate ACP 

• Assess timing of booming operations to ensure it is where it needs to be at time of impact. 

Consider: 

o Trajectories 

o Weather forecast 

o Oil Impact forecast 

o Verified spill movement 

o Boom, manpower and vessel (shallow draft) availability 

o Near shore boom and support material, (stakes, anchors, line) 

Beach Preparation 

Considerations and Actions 

• Use of a 10 mile go/no go line to determine timing of beach cleaning 

• Shoreline Cleanup and Assessment Team Reports and recommendations 

• Determination of Archeological sites and gaining authority to enter 

• Monitoring of tide tables and weather to determine extent of high tides 

• Pre cleaning of beaches by moving waste above high time lines to minimize waste 

• Staging of equipment and housing of response personnel as close to the job site as possible to 

maximize on-site work time 

• Boom tending, repair, replacement and security (use of local assets may be advantageous) 

• Constant awareness of weather and oil movement for resource redeployment as necessary 

• In-situ burn may be considered when marshes have been impacted 

• Passive clean up of marshes should considered and appropriate stocks of sorbent boom and/or 

sweep obtained 

• Earthen berms and shoreline protection boom may be considered to protect sensitive inland 

areas 
Decanting Strategy 

Recovered oil and water mixtures will typically separate into distinct phases when left in a quiescent state. 

When separation occurs, the relatively clean water phase can be siphoned or decanted back to the 

recovery point with minimal, if any, impact. Decanting therefore increases the effective on-site oil storage 

capacity and equipment operating time. FOSC/SOSC approval will be requested prior to decanting 

operations. This practice is routinely used for oil spill recovery. 

CGA Equipment Limitations 

The capability for any spill response equipment, whether a dedicated or portable system, to operate in 

differing weather conditions will be directly in relation to the capabilities of the vessel the system in placed 

on. Most importantly, however, the decision to operate will be based on the judgment of the Unified 

Command and/or the Captain of the vessel, who will ultimately have the final say in terminating 

operations. Skimming equipment listed below may have operational limits which exceed those safety 

thresholds. As was seen in the Deepwater Horizon (DWH) oil spill response, vessel skimming operations 

ceased when seas reached 5-6 feet and vessels were often recalled to port when those conditions were 

exceeded. Systems below are some of the most up-to-date systems available and were employed during 

the DWH spill. 

Boom 3 foot seas, 20 knot winds 

Dispersants Winds more than 25 knots 

Visibility less than 3 nautical miles 

Ceiling less than 1,000 feet. 

FRU 8 foot seas 

HOSS Barge/OSRB 8 foot seas 

Koseq Arms 8 foot seas 

OSRV 4 foot seas 

Environmental Conditions in the GOM

Louisiana is situated between the easterly and westerly wind belts, and therefore, experiences westerly 

winds during the winter and easterly winds in the summer. Average wind speed is generally 14-15 mph 

along the coast. Wave heights average 4 and 5 feet. However, during hurricane season, Louisiana has 

recorded wave heights ranging from 40 to 50 feet high and winds reaching speeds of 100 mph. Because 

much of southern Louisiana lies below sea level, flooding is prominent. 

Surface water temperature ranges between 70 and 80 F during the summer months. During the winter, 

the average temperature will range from 50 and 60 F. 

The Atlantic and Gulf of Mexico hurricane season is officially from 1 June to 30 November. 97% of all 

tropical activity occurs within this window. The Atlantic basin shows a very peaked season from August 

through October, with 78% of the tropical storm days, 87% of the minor (Saffir-Simpson Scale categories 

1 and 2) hurricane days, and 96% of the major (Saffir-Simpson categories 3, 4 and 5) hurricane days 

occurring then. Maximum activity is in early to mid September. Once in a few years there may be a 

hurricane occurring "out of season" - primarily in May or December. Globally, September is the most 

active month and May is the least active month. 
FIGURE 1 

TRAJECTORY BY LAND SEGMENT 

Trajectory of a spill and the probability of it impacting a land segment have been projected utilizing 

Woodside Energy (USA) Inc.’s WCD and information in the BOEM Oil Spill Risk Analysis Model 

(OSRAM) for the Central and Western Gulf of Mexico available on the BOEM website using 30 

day impact. The results are tabulated below. 

Area/Block OCS-G Launch 

Area 

Land Segment and/or 

Resource 

Conditional 

Probability (%) within 

30 days 

Exploratory Drilling 

GC 451 

G32509 C43 Matagorda County, TX 

Brazoria County, TX 

Galveston County, TX 

Jefferson County, TX 

Cameron Parish, LA 

Vermilion Parish, LA 

Iberia Parish, LA 

Terrebonne Parish, LA 

Lafourche Parish, LA 

Plaquemines Parish, LA 

30 day 

2 

1 

3 

2 

7 

3 

1 

3 

1 

2
WCD Scenario– BASED ON WELL BLOWOUT DURING DRILLING OPERATIONS (109 miles from shore) 

159,951 bbls of crude oil API Gravity 29° 

FIGURE 2 – Equipment Response Time to Green Canyon 451 

Dispersants/Surveillance 

Dispersant/Surveillance Dispersant Capacity (gal) Storage Capacity Persons Req. From Hrs to Procure Hrs to Loadout Trav

CGA Equipment

Basler 67T 2000 NA 2 Houma 1 1 

ASI Equipment

DC 3 1000 NA 2 Houma 1 1 DC 3 1000 NA 2 Houma 1 1 Aero Commander NA NA 2 Houma 1 1 

Offshore Response 

Offshore Equipment No 

Staging EDRC Storage Capacity VOO Persons Required From Hrs to Procure Hrs to Loadout Hrs to GOM T

S

CGA Equipment 

HOSS Barge 43000 4000 3 Tugs 8 Houma 4 0 5 

NRCC Equipment 

OSRB Defender (Marco Class XI AB) 24000 16500 1 Tug 6 Bayou La Batre 4 2 0 OSRV Admiral (Marco Class XI AB) 24000 300 NA 6 Galveston 4 2 0 

Recovered Oil Storage No 

Staging EDRC Storage Capacity VOO Persons Required From Hrs to Procure Hrs to Loadout Hrs to GOM T

S

Enterprise Marine Services LLC (available through CGA agreement) 

CTCo 2603 NA 25000 1 Tug 6 Amelia 4 0 4 CTCo 2604 NA 20000 1 Tug 6 Amelia 4 0 4 CTCo 2605 NA 20000 1 Tug 6 Amelia 4 0 4 CTCo 2606 NA 20000 1 Tug 6 Amelia 4 0 4 CTCo 2607 NA 23000 1 Tug 6 Amelia 4 0 4 CTCo 5001 NA 47000 1 Tug 6 Amelia 4 0 4 
Offshore Equipment With Staging EDRC Storage Capacity VOO Persons Req. From Hrs to Procure Hrs to Load Out Travel to Staging 

Staging Area: Fourchon

CGA Equipment 

FRU (1) + 100 bbl Tank (2) 3770 200 1 Utility 6 Galveston 1 2 7 FRU (3) + 100 bbl Tank (5) 11310 500 1 Utility 6 Houma 1 2 1 FRU (1) + 100 bbl Tank (2) 3770 200 1 Utility 6 Lake Charles 1 2 4 42” Auto Boom (5000’) NA NA 10 Crew 20 Galveston 1 2 7 42” Auto Boom (5000’) NA NA 10 Crew 20 Houma 1 2 1 42” Auto Boom (2500’) NA NA 6 Crew 12 Ingleside 1 2 9.5 42” Auto Boom (5000’) NA NA 10 Crew 20 Lake Charles 1 2 4 

NRCC Equipment 

4-Band Rope Mop + 100 bbl Tank 1509 100 1 Utility 4 Morgan City 1 2 2.5 8-Band Rope Mop + 100 bbl Tank 2283 100 1 Utility 4 Galveston 1 2 7 Vikoma Cascade + 100 bbl Tank 5520 100 1 Utility 4 Houston 1 2 7 Vikoma Cascade + 100 bbl Tank 5520 100 1 Utility 4 Sulphur 1 2 5 Portable Barge Set 238 bbls (12) NA 2856 Towed 0 Houma 1 2 1 Portable Barge Set 238 bbls (2) NA 476 Towed 0 Morgan City 1 2 2.5 Portable Barge Set 238 bbls (1) NA 238 Towed 0 Sulphur 1 2 5 Canflex FCB-43E Bladder 100 bbls (3) NA 300 Towed 0 Morgan City 1 2 2.5 Portable Barge Set 238 bbls (1) NA 238 Towed 0 Houston 1 2 7 Portable Barge Set 238 bbls (1) NA 238 Towed 0 Corpus Christi 1 2 10.5 42” Auto Boom (2100’) NA NA 6 Crew 12 Morgan City 1 2 2.5 42” Auto Boom (2000’) NA NA 6 Crew 12 Houston 1 2 7 42” Auto Boom (2200’) NA NA 6 Crew 12 Galveston 1 2 7.5 42” Auto Boom (2700’) NA NA 6 Crew 12 Aransas Pass 1 2 10.5 42” Auto Boom (4000’) NA NA 8 Crew 16 Corpus Christi 1 2 10.5 
Offshore Equipment With 

Staging EDRC Storage Capacity VOO Persons Req. From Hrs to Procure Hrs to Loadout Travel to Staging 

Staging Area: Venice

CGA Equipment 

FRU (1) + 100 bbl Tank (2) 3770 200 1 Utility 6 Belle Chasse 1 2 2 FRU (2) + 100 bbl Tank (4) 7540 400 1 Utility 6 Venice 1 2 0 42” Auto Boom (5000’) NA NA 10 Crew 20 Belle Chasse 1 2 2 42” Auto Boom (2500’) NA NA 6 Crew 12 Pascagoula 1 2 4 1000’ Hydro-Fire Boom (In-Situ Burn) NA NA 8 Utility 40 Belle Chasse 1 4 2 

NRCC Equipment 

Vikoma Cascade + 100 bbl Tank 5520 100 1 Utility 4 Mobile 1 2 4.5 Marco Class XI AB Skimmer 24000 300 1 Utility 4 Belle Chasse 1 2 2 Portable Barge Set 238 bbls (1) NA 238 Towed 0 Mobile 1 2 4.5 42” Auto Boom (200’) NA NA 3 Crew 6 Belle Chasse 1 2 2 42” Auto Boom (1000’) NA NA 3 Crew 6 Bayou La Batre 1 2 4 
Nearshore Response 

Nearshore Equipment 

No Staging EDRC Storage Capacity VOO Persons Required From Hrs to Procure Hrs to Loadout Hrs to GOM T

t

CGA Equipment

46’ FRV 5000 65 NA 4 Galveston 1 0 0 46’ FRV 5000 65 NA 4 Houma 1 0 2 46’ FRV 5000 65 NA 4 Lake Charles 1 0 1 46’ FRV 5000 65 NA 4 Venice 1 0 1 

Enterprise Marine Services LLC (available through CGA agreement)

CTCo 2608 NA 23000 1 Tug 6 Amelia 4 0 4 CTCo 2609 NA 23000 1 Tug 6 Amelia 4 0 4 

Nearshore and Inland Skimmers 

With Staging EDRC Storage Capacity VOO Persons Req. From Hrs to Procure Hrs to Loadout Travel to Staging 

D

Staging Area: Cameron 

CGA Equipment 

SWS Egmopol 3000 100 NA 3 Galveston 1 2 3.5 SWS Egmopol 3000 100 NA 3 Houma 1 2 4 SWS Marco 3588 34 NA 3 Houma 1 2 4 SWS Marco 3588 20 NA 3 Lake Charles 1 2 1 Rope Mop 77 2 0 3 Belle Chasse 1 2 4.5 RO Storage Barge NA 249 Towed 0 Galveston 1 2 3.5 RO Storage Barge NA 249 Towed 0 Houma 1 2 4 RO Storage Barge NA 249 Towed 0 Lake Charles 1 2 1 RO Storage Barge NA 249 Towed 0 Venice 1 2 6.5 
Shoreline Protection 

Staging Area: Cameron 

Feet VOO Persons Req. Storage/Warehouse Location Hrs to Procure Hrs to Loadout Travel to Staging Travel to Deployment Site 

Oil Mop (available through MSA) 

10,000’ 18” Boom 4 Crew 10 New Iberia, LA 1 1 2.5 2 10,000’ 18” Boom 4 Crew 10 Houston, TX 1 1 2.5 2 10,000’ 18” Boom 4 Crew 10 Port Arthur, TX 1 1 1.25 2 

Beach Boom EDRC Storage Capacity VOO Persons Req. From Hrs to Procure Hrs to Load Out Travel to Staging 

D

CGA Equipment

Beach Boom (2000’) NA NA NA 6 Galveston 1 2 3.5 Beach Boom (1000’) NA NA NA 4 Ingleside 1 2 6 Beach Boom (2000’) NA NA NA 6 Pascagoula 1 2 5.5 

Wildlife Response EDRC Storage Capacity VOO Persons Req. From Hrs to Procure Hrs to Load Out Travel to Staging 

D

CGA Equipment

Wildlife Support Trailer NA NA NA 2 Houma 1 2 4 Bird Scare Guns (24) NA NA NA 2 Belle Chasse 1 2 4.5 Bird Scare Guns (12) NA NA NA 2 Galveston 1 2 3.5 Bird Scare Guns (24) NA NA NA 2 Houma 1 2 4 Bird Scare Guns (12) NA NA NA 2 Ingleside 1 2 6 Bird Scare Guns (24) NA NA NA 2 Lake Charles 1 2 1 Bird Scare Guns (24) NA NA NA 2 Pascagoula 1 2 5.5 

Response Asset Total Response Asset Total 

Offshore EDRC 165,512 Nearshore / Shallow Water EDRC 33,253 Offshore Recovered Oil Capacity 182,684 Nearshore / Shallow Water Recovered Oil Capacity 47,512 



NATI(}HAL RESPONSE

co'|poRATroN

6620 CYPRESSWOOD DRlvE. STE.201

SPRING, TEXAS 77379

(281) 899-4&18 . FAX {281i 89s-4849

a SEACORcompany

Please be advised that Woodside Energy (USA) Inc. cunently has a memberchip

agreernent with National Response Corporation (NRC) as equipment provider and

the follovying contracts or agreements by way of NRC membership:

The subject contracts or membership agreements provide immediate access

to available personnelandlor eguipment on a 24-hour per day basis.

ou,/tAoro

COf, POEATE HEADQUAftTERS

3500 SUNHISE HIGHWAY. SUI?E 103

GREAT RIVER, NY 11739

(6811 224*9141 ' FAX {631} 224-sa82

REGIOHAL OFFICES

HOUSTON,TX SAN JUAN, PR

MEMPHIS, TN SEATTLE, WA

MORGAN C'TY, LA SI CRO'X, USVI

N€WYORK, NY TAMPA, FL

Helix Well Containment Group 

Please be advised that Woodside Energy USA, Inc. currently has a contract and is a valid

member of Helix Well Containment Group as a provider for well containment. The 

subject contract provides immediate access to available equipment and personnel on a 

24-hour per day basis for well containment. Let this letter serve as verification of 

contract for Woodside Energy USA, Inc. 

Helix Well Containment Group

 Commercial Director 

 Roger Scheuermann

 

__________________________

 Date:__May 13, 2011_________