UNITED STATES GOVERNMENT MEMORANDUM

To: Public Information (MS 5030)

Plans Section, Office of Field 

Operations (MS 5231)

Public Information copy of Exploration Plan

Control # - N-09609

Type - Initial Exploration Plan

Lease(s) - OCS-G33375 Block - 376 Walker Ridge Area

Operator - Petrobras America Inc.

Subsea Wells A, B, and D

DRILLSHIP

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.

Jay Preskitt

Plan Coordinator

Description -

Rig Type -

Subject:

From:

March 13, 2012
PUBLIC INFORMATION COPY 

November, 2011 

INITIAL EXPLORATION PLAN 

Lease Number(s): OCS-G 33375 

Area/Block: Walker Ridge Block 376 

Prospect Name: Ipanema 

Offshore: Louisiana 

Submitted by: Petrobras America Inc. 

 10350 Richmond Avenue 

 Suite 1400 

 Houston, Texas 77042 

 Gregory D. Roland 

 (713) 808-2881 

 groland@petrobras-usa.com 

Estimated Start-up Date: May 15, 2012 

Authorized Representative: No. Copies Being Submitted: 

Melissa Flack or Judy Davidson Proprietary: 1 Copy & CD 

J. Connor Consulting, Inc. Public Info: 1 Copy & CD 

16225 Park Ten Place, Suite 700 

Houston, Texas 77084 For BOEM: 

(281) 578-3388 Plan No. N-9609 0 

Melissa.Flack@jccteam.com

Judy.Davidson@jccteam.com 

Assigned to: Mimi Griffit t
Walker Ridge Block 376 (Control Number N-9609) Record of Changes 

PUBLIC INFORMATION 

Date Section Page Revision 

11/15/11 All All Initial Plan Submitted 

12/06/11 

Appendix A All Storage Tank Capacities 

Appendix B All The Blowout Scenario and include Attachment B-1 

for proprietary copy 

Appendix G G-1 Calculated Exemption Amount 

Appendix H H-1 EP-WCD Facility Designation 

12/08/11 Attachment B Page 18-21 Directional Survey 

Attachment C-3 Page 7 Proprietary Geologic Information 

12/20/11 Attachment C-3 Page 7 Proprietary Geologic Information 

12/22/11 Attachment C-3 Page 7 Proprietary Geologic Information 

02/22/12 

Record of Change 1 Record of Change Reflecting Amendments 

Appendix B Page 2 Amended the WCD volume 

Appendix H All 

Amended WCD per BSEE, OSRP modification 

Submittal Date, and Revise Spill Response 

Discussion 
PETROBRAS AMERICA INC. 

INITIAL EXPLORATION PLAN 

LEASE OCS-G 33375 

 WALKER RIDGE BLOCK 376 

APPENDIX A Plan Contents 

APPENDIX B General Information

APPENDIX C Geological, Geophysical Information

APPENDIX D H2S Information 

APPENDIX E Biological, Physical and Socioeconomic Information

APPENDIX F Wastes and Discharge Information 

APPENDIX G Air Emissions Information

APPENDIX H Oil Spills Information

APPENDIX I Environmental Monitoring Information 

APPENDIX J Lease Stipulations Information 

APPENDIX K Environmental Mitigation Measures Information 

APPENDIX L Support Vessels and Aircraft Information 

APPENDIX M Onshore Support Facilities Information 

APPENDIX N Coastal Zone Management Act (CZMA) Information 

APPENDIX O Environmental Impact Analysis

APPENDIX P Administrative Information 
LIST OF ATTACHMENTS 

A-1 OCS Plan Information Form 

A-2 Well Location Plat 

A-3 Bathymetry Map 

A-4 Pay.Gov Receipt 

B-1 Nodal Analysis 

C-1 Structure Contour Maps 

C-2 3-D Seismic Lines 

C-3 Geological Structure Cross Sections 

C-4 Shallow Hazard Assessment 

C-5 Stratigraphic Column 

C-6 Time vs. Depth Tables 

E-1 Bathymetry and Seafloor Features Map 

E-2 Sensitive Benthic Communities Statement Letters 

F-1 Projected Generated Wastes 

L-1 Solid and Liquid Waste Transportation 

L-2 Vicinity Map 

N-1 Coastal Zone Management Consistency Certification
Petrobras America Inc. Page A-1 

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

APPENDIX A 

PLAN CONTENTS 

(A) PLAN INFORMATION FORM 

Petrobras America Inc. (PAI) became operator of Walker Ridge Block 376 in June, 2009. To 

date, no wells have been drilled on this lease. Under this Initial Exploration Plan, PAI proposes 

to drill and complete three wells, Locations A, B and D. The wells will be drilled with a drillship. 

Water depths across the block range from 6,225’ to 7,550’. 

See attached OCS Plan Information Forms – Form BOEM-137, included as Attachment A-1. 

(B) LOCATION 

Included as Attachment A-2 is a Well Location Map depicting the proposed surface and bottom 

bottom-hole locations of the proposed wells. Included as Attachment A-3 is a bathymetry map 

showing the water depths across the lease block. 

(C) SAFETY AND POLLUTION PREVENTION FEATURES

There are no proposed new or existing facilities that will be utilized for these operations. A 

description of the drilling unit is included on the OCS Plan Information Form. Rig specifications 

will be made part of each Application for Permit to Drill. 

The drillship is equipped with a Subsea BOP. Once a rig is contracted, BOP information and 

schematics will be included as a part of the Applications for Permit to Drill. 

Safety features on the drilling unit will include well control, pollution prevention, and blowout 

prevention equipment as described in 30 CFR Part 250, Subparts C, D, E, O and S; and as 

further clarified by BOEM/BSEE Notices to Lessees, and current policy making invoked by the 

BOEM/BSEE, Environmental Protection Agency and the U.S. Coast Guard. Appropriate life 

rafts, life jackets, ring buoys, etc., will be maintained on the facility at all times. 

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

drilling deck areas to collect all contaminants and debris. 

(D) STORAGE TANKS AND/OR PRODUCTION VESSELS 

All facility tanks of 25 barrels or more. 

Type of 

Storage Tank 

Type of 

Facility 

Tank Capacity of 

Largest Facility 

Proposed (bbls) 

Number 

of Tanks 

Total 

Capacity 

(bbls) 

Fluid 

Gravity 

(API) 

Fuel Oil (Marine Diesel) Drillship 478 2 956 50° 

Fuel Oil (Marine Diesel) Drillship 11,982 2 23,964 50° 

Fuel Oil (Marine Diesel) Drillship 6,434 2 12,868 50° 
Petrobras America Inc. Page A-2 

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

Fuel Oil (Marine Diesel) Drillship 259 1 259 50° 

Base Oil Drillship 1 1 5,032 45° 

(E) ADDITIONAL MEASURES 

PAI does not propose additional safety, pollution prevention, or early spill detection measures 

beyond those required by 30 CFR Part 250 and Part 550. 

(F) COST RECOVERY FEE 

Included as Attachment A-4 is a pay.gov receipt in the amount of $10,326.00 to cover operations 

proposed in this plan.
U.S Department of the Interior OMB Control Number: 1010-0151 

Bureau of Ocean Energy Management OMB Approval Expires: 12/31/2011*

OCS PLAN INFORMATION FORM 

FORM BOEM-0137 (October 2011 – Supersedes all previous editions of form BOEM-0137, which may not be used. 

*Collection has been submitted to OMB and is automatically renewed each month until approval.) 

General Information 

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

Company Name: Petrobras America Inc. BOEM Operator Number: 01207 

Address: 10350 Richmond Avenue Contact Person: Judy Davidson 

 Suite 1400 Phone Number: (281) 578-3388 

 Houston, Texas 77042 Email Address: Judy.Davidson@jccteam.com 

Lease(s):OCS-G 33375 Area: Walker Ridge Block(s): 376 Project Name (If Applicable): Ipanema 

Objective(s): Oil Gas Sulphur Salt Onshore Base: Fourchon, LA Distance to Closest Land (Miles): 169 

Description of Proposed Activities (Mark all that apply) 

 Exploration drilling Development drilling 

 Well completion Installation of production platform 

 Well test flaring (for more than 48 hours) Installation of production facilities 

 Installation of caisson or platform as well protection structure Installation of satellite structure 

 Installation of subsea wellheads and/or manifolds Commence production 

 Installation of lease term pipelines Other (Specify and describe) 

Have you submitted or do you plan to submit a Conservation Information Document to accompany this plan? 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 development? Yes X No 

Do you propose any activities that may disturb an BOEM-designated high-probability archaeological area? Yes X No 

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

Tentative Schedule of Proposed Activities 

Proposed Activity Start Date End Date No. of Days 

Drill, Complete, Potentially Test and TA WR 376 Well A 5/15/2012 10/6/2012 145 

Drill, Complete, Potentially Test and TA WR 376 Well B 1/01/2013 5/26/2013 145 

Drill, Complete, Potentially Test and TA WR 376 Well D 1/01/2014 5/26/2014 145 

 

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 

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

 Drilling Rig Name (If Known): Spar Other (Attach description) 

Description of Lease Term Pipelines 

From (Facility/Area/Block) To (Facility/Area/Block) Diameter (inches) Length (Feet) 

 

 

 ATTACHMENT A-1 
OCS PLAN INFORMATION FORM (CONTINUED) 

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

FORM BOEM-0137 (October 2011 – Supersedes all previous editions of form BOEM-0137, which may not be used.) 

Proposed Well/Structure Location 

Well or Structure Name/Number (If renaming well or structure, reference previous name): Well A Subsea Completion 

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

Surface Location Bottom-Hole Location (For Wells) 

Lease No. OCS-G 33375 

Area Name Walker Ridge 

Block No. 376 

Blockline 

Departures 

(in feet) 

N/S Departure: 3,719’ FSL 

E/W Departure: 4,177’ FWL 

Lambert X-Y 

coordinates 

X: 2,364,337’ 

Y: 9,650,279’ 

Latitude/ 

Longitude 

Latitude: 26° 34’ 39.85” N 

Longitude: 90° 47’ 4.64” W 

 TVD (Feet): MD (Feet): Water Depth (Feet): 6,558’ 

Anchor Locations for Drilling Rig or Construction Barge (If anchor radius supplied above, not necessary) 

Anchor Name 

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

Chain on Seafloor

 X = Y = 

 X = Y = 

 X = Y = 

 X = Y = 

 X = Y = 

 X = Y = 

 X = Y = 

 X = Y = 

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

inform you that BOEM collects this information as part of an applicant’s Exploration Plan or Development Operations 

Coordination Document submitted for BOEM 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 550.197. 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 hours per response, or 640 with an accompanying EP (1,000 hours in AKOCSR), or 690 (1,700 in 

AKOCSR) 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, Bureau of Ocean Energy Management, 381 Elden Street, 

Herndon, VA 20170.
OCS PLAN INFORMATION FORM (CONTINUED) 

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

FORM BOEM-0137 (October 2011 – Supersedes all previous editions of form BOEM-0137, which may not be used.) 

Proposed Well/Structure Location 

Well or Structure Name/Number (If renaming well or structure, reference previous name): Well B Subsea Completion 

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

Surface Location Bottom-Hole Location (For Wells) 

Lease No. OCS-G 33375 

Area Name Walker Ridge 

Block No. 376 

Blockline 

Departures 

(in feet) 

N/S Departure: 2,367’ FSL 

E/W Departure: 5,394’ FWL 

Lambert X-Y 

coordinates 

X: 2,365,554’ 

Y: 9,648,927’ 

Latitude/ 

Longitude 

Latitude: 26° 34’ 26.26” N 

Longitude: 90° 46’ 51.50” W 

 TVD (Feet): MD (Feet): Water Depth (Feet): 6,687’ 

Anchor Locations for Drilling Rig or Construction Barge (If anchor radius supplied above, not necessary) 

Anchor Name 

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

Chain on Seafloor

 X = Y = 

 X = Y = 

 X = Y = 

 X = Y = 

 X = Y = 

 X = Y = 

 X = Y = 

 X = Y = 

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

inform you that BOEM collects this information as part of an applicant’s Exploration Plan or Development Operations 

Coordination Document submitted for BOEM 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 550.197. 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 hours per response, or 640 with an accompanying EP (1,000 hours in AKOCSR), or 690 (1,700 in 

AKOCSR) 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, Bureau of Ocean Energy Management, 381 Elden Street, 

Herndon, VA 20170.
OCS PLAN INFORMATION FORM (CONTINUED) 

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

FORM BOEM-0137 (October 2011 – Supersedes all previous editions of form BOEM-0137, which may not be used.) 

Proposed Well/Structure Location 

Well or Structure Name/Number (If renaming well or structure, reference previous name): Well D Subsea Completion 

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

Surface Location Bottom-Hole Location (For Wells) 

Lease No. OCS-G 33375 

Area Name Walker Ridge 

Block No. 376 

Blockline 

Departures 

(in feet) 

N/S Departure: 3,155’ FSL 

E/W Departure: 5,300’ FWL 

Lambert X-Y 

coordinates 

X: 2,365,460’ 

Y: 9,649,715’ 

Latitude/ 

Longitude 

Latitude: 26° 34’ 34.07” N 

Longitude: 90° 46’ 52.38” W 

 TVD (Feet): MD (Feet): Water Depth (Feet): 6,592’ 

Anchor Locations for Drilling Rig or Construction Barge (If anchor radius supplied above, not necessary) 

Anchor Name 

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

Chain on Seafloor

 X = Y = 

 X = Y = 

 X = Y = 

 X = Y = 

 X = Y = 

 X = Y = 

 X = Y = 

 X = Y = 

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

inform you that BOEM collects this information as part of an applicant’s Exploration Plan or Development Operations 

Coordination Document submitted for BOEM 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 550.197. 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 hours per response, or 640 with an accompanying EP (1,000 hours in AKOCSR), or 690 (1,700 in 

AKOCSR) 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, Bureau of Ocean Energy Management, 381 Elden Street, 

Herndon, VA 20170.
±

3® 3

3

3

3® 3

3

3

3® 3

3

3

3® 3

3

3

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-6700

-6500

-6750

-6675

-6550 -6525

-6575

-6650

-6625

-6600

-6475 -6450

-677

-

5

6800

-6825

-6850

-6875

-6900

-6925

-6950

-6975

-6425

-7000

-7025

-7050

-6400

-7075

-6375 -6350

-7100

-7125

-6325

-7150

-6300

-717

-7

5

200

-7225

-7250

-6275

-6650

-6575

-6325

-6475

-6275

-6925

-6575

-6825

-6300

-6700

-6400

-6375

-6775

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-6375

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90°45'0"W90°46'0"W90°47'0"W

26°36'0"N

26°35'0"N

26°34'0"N

2,365,0002,370,0002,375,000

9,645,000

9,650,000

9,655,000

9,660,000

0 500 1,000 2,000 Feet

0 125 250 500 Meters

Chart scale 1" = 2,000'

Bathymetry Plat Figure 11

Proposed WR376-A

X: 2,364,337

Y: 9,650,279

FWL of Walker Ridge 376: 4,177ft

FSL of Walker Ridge 376: 3,719ft

Proposed WR376-C & D

X: 2,365,460

Y: 9,649,715

FWL of Walker Ridge 376: 5,300ft

FSL of Walker Ridge 376: 3,155ft

Proposed WR376-B

X: 2,365,554

Y: 9,648,927

FWL of Walker Ridge 376: 5,394ft

FSL of Walker Ridge 376: 2,367ft

BLOCK WR376 (OCS-G33375)

Proposed WR376-E (With Surface Location In WR420)

X: 2,362,221

Y: 9,645,771

FWL of Walker Ridge 376: 2,061ft

FNL of Walker Ridge 376: 789ft

Petrobras America Inc. Page B-1 

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

APPENDIX B 

GENERAL INFORMATION 

(A) APPLICATIONS AND PERMITS 

Listed in the table below are additional permits/applications to be filed before operations can 

commence under this EP: 

Application/Permit Issuing Agency Status 

Applications for Permit to 

Drill BSEE To be submitted 

(B) DRILLING FLUIDS 

Type of Drilling Fluid Estimated Volume of Drilling Fluid to be 

Used per Well 

Water-based – 

Barite, Sodium Chloride Brine, Salt, Xantham 

Gum, Poly Plus, Lime, Poly Pac UL, Caustic 

Soda, Defoam X, 

Greencide 25g 

16,000 bbls water based mud

Oil-based (diesel, minerals, oil) 0 bbls 

Synthetic-based (internal olefin, ester) 

Barite, Suremul, Surewet, Rheflat, Rhethik, 

Ecotrol RD, Rheduce, Rhebuild, Lime, 

Calcium Chloride, Vg Plus, Vg Supreme, 

Calcium Carbonate, G-Seal, Nut Plug, Vinseal 

7,200 bbls synthetic based mud 

(C) NEW OR UNUSUAL TECHNOLOGY 

PAI does not propose to use any new or unusual technology to carry out the proposed 

exploration activities. 

(D) BONDING STATEMENT 

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

$3,000,000.00 areawide development bond, furnished and maintained according to 30 CFR 556, 

subpart I; NTL No. 2000-G16, "Guidelines for General Lease Surety Bonds;" and additional 

security under 30 CFR 256.53(d) and National NTL No. 2008-N07, “Supplemental Bond 

Procedures.” 

(E) OIL SPILL FINANCIAL RESPONSIBILITY (OSFR) 

Petrobras America Inc., BOEM company number 01207 will demonstrate oil spill financial 

responsibility for the facilities proposed in this EP according to 30 CFR Part 553; and NTL No. 

2008-N05, "Guidelines for Oil Spill Financial Responsibility (OSFR) for Covered Facilities". 
Petrobras America Inc. Page B-2 

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

(F) DEEPWATER WELL CONTROL STATEMENT 

Petrobras America Inc., BOEM company number 01207 has or will have the financial capability 

to drill a relief well and conduct other emergency well control operations. 

(G) BLOWOUT SCENARIO 

Estimated flow rate – The calculated Worst Case Discharge estimate for Walker Ridge Block 

376 is 43,595 barrels of oil. 

Potential for the Well to Bridge over: 

The Wilcox reservoirs expected to be encountered in the Ipanema Field are competent, hard rock 

with low permeability sandstones with an unknown water drive mechanism. Although the flow 

rate is likely to decline over the duration of a blowout, for WCD purposes, we have assumed for 

Ipanema a constant flow rate of 43,595 with no decline. In keeping with the conservative 

approach to WCD calculations, the reservoirs are considered very unlikely to bridge over due to 

the high compressive strength of the rocks. 

Likelihood of Surface Intervention: 

In the unlikely event of a “kick” or loss of well control event, surface intervention, defined as the 

normal well control methods which include wellbore fluid control or overbalance, diverter and 

BOP operations to shut-in the well from the surface will be the primary response. 

The present well design is based on predicted pore pressure and fracture gradient estimates 

derived from the best available data. The well design in conjunction with actual pore pressure, 

actual fluids and actual fracture gradients encountered will dictate the use of either the Cap and 

Stack or Cap and Flow method to regain control of the well. The assumption that the well can be 

shut-in with the present well design and selected BOP is based on predicted measurements of the 

pore pressure, fluids and fracture gradients. Relief well planning will commence in conjunction 

with the subsea capping efforts. 

Arrangements for Drilling Relief Wells / Estimated Blowout Duration: 

Should surface intervention prove unsuccessful, PAI has evaluated two additional potential 

scenarios to kill a blowout; seafloor intervention and a relief well. This would involve subsea 

intervention in the form of; ROV control of the BOP stack via hot stabs, a shut off device 

mounted on the BOP stack or LMRP, or diverting flow to a surface vessel. Seafloor intervention 

would take an estimated 20 days to kill the well, which would result in a total discharge volume 

of 871,900 barrels of oil. In parallel with this operation, a rig will be mobilized (approximately 

20 deepwater rigs capable of this water depth and hook loads currently work in the GOM) to drill 

a relief well, estimated to be 14 days to contract, 14 days to mobilize and 76 days to kill the well 

which would result in a total discharge volume of 4,533,880 barrels of oil. 

Table 1 provides a probable timeline that would be required towards efforts to kill the well by 

drilling a relief well in case of a potential blowout. The time range required for this purpose 

would be from a minimum of 65 days to a maximum of 104 days. For our calculations we used 

the maximum time of 104 days to estimate the total discharge in case of a blow out. 
Petrobras America Inc. Page B-3 

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

Table 1: Timeline for drilling a relief well 

Operation Minimum Time 

Required 

Maximum Time 

Required 

Contract a rig 0 14 

MOB 7 14 

Riserless Operations 10 13 

Drilling Operations 33 43 

Kill Operations 15 20 

Total Days 65 104 

Rig Type Capable of Drilling a Relief Well / Rig Package Constraints: 

Should a relief well be required, a deepwater rig currently located in the GOM would be 

contracted to drill the relief well. As of November 2010, there are approximately 20 rigs in the 

GOM capable of drilling an Ipanema relief well. The rig must be capable of drilling to a depth 

of 30,000 feet in a water depth of 6,558 feet. This rig will be a rig of no constraints. There are 

no platforms or other structures in the vicinity for drilling a relief well. PAI expects to have a 2-

rig operation by 2012, with a rig operating in the Cascade/Chinook Field while the other is 

operating in the Ipanema Field. 

The requirements for dynamically positioned rigs include both a deadman system to shut-in the 

well in the event of complete loss of communication to the subsea BOPE and an autoshear 

system to shut-in the well in the event of an accidental disconnect. ROV hot stabs will be in 

place and function tested to ensure that they are capable of closing one pipe ram, close the blind 

shear ram, and unlatch the LMRP. 

In the event of a blowout, the 104-day window may be necessary to secure a rig, mobilize to the 

location, drill the relief well and kill the blowout well. PAI will work with specific partners and 

industry to develop rig-sharing agreements to allow faster mobilization in the event of an 

emergency. 

Measures to Enhance the Ability to Prevent a Blowout: 

Well Control Training 

PAI requires certified well control training for drilling supervisors, operations superintendents, 

drilling engineers, and the drilling contractor requires training for tool pushers, drillers & 

assistant drillers, floor hands, and other appropriate personnel through an operations training 

program with a professional organization and in accordance with BSEE/BOEM requirements. 

The curriculum consists of training in blowout prevention technology and well control. 

Successful completion results in participant certification. 

Inspection of Well Control Equipment 

The rig and its equipment will have undergone a comprehensive inspection and testing program 

pursuant to 30 CFR 250 “Increased Safety Measures for Energy Development in the OCS”; 
Petrobras America Inc. Page B-4 

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

Final Rule October 14, 2010. Routine functional and pressure testing during future drilling and 

completion operations will be conducted in compliance with PAI and BSEE/BOEM 

requirements. 

Measures to reduce the likelihood of a Blowout: 

Well Control during Drilling Operations 

Effective well control during drilling and completion reduces the likelihood of a blowout and 

relies on a number of interrelated processes and procedures. The drilling or completion fluid 

provide Primary Well Control during operations with the fluid density providing hydrostatic 

pressure on the wellbore which exceeds the pore pressures within the drilled or open hole 

formations. This overbalance prevents fluid flow from the pore space in the formation to flow 

into the wellbore. Subsea-mounted Blowout Prevention Equipment (BOPE) will provide 

Secondary Well Control during drilling or completion operations. In the event that primary well 

control is lost, the BOPE will contain the influx out of the wellbore. 

Well Control drills/exercises are an integral part of the rig teams training and will be performed 

on a frequent basis to ensure the human element is prepared, and the well can be shut in quickly 

and properly. Certified training of Gulf of Mexico personnel will include hands-on simulator 

practice at recognizing kicks, well shut-in, and circulating the kicks out of the wellbore. Well 

specific shut-in procedures will be posted on the rig. 

Well Control Monitoring and Procedures 

Automatic and manual monitoring equipment will be installed to detect abnormal variation in the 

mud system volumes and drilling parameters. If an influx of formation fluid into the wellbore 

occurs, the BOPE will be used to immediately shut-in the well. 

Each well will be drilled according to a location specific pore pressure profile and detailed safe 

mud weight envelope. Too low of a mud weight could result in an under-balance in the well, and 

an influx of formation fluids. Conversely, too high of a mud weight may result in lost circulation 

to a weak formation, which could lead to a drop in fluid level (total hydrostatic column) resulting 

in an under-balanced condition. The mud weight envelope is designed to provide the proper 

balance for well control for the formation and pore pressure encountered. 

Measures to Enhance Ability to Conduct Effective and Early Intervention in the Event of a 

Blowout: 

In case an uncontrolled influx of formation fluid (water or hydrocarbon), or “Kick” does occur, 

Secondary Well Control methods will be employed, i.e., the kick is quickly detected, the pumps 

are turned off, the annulus will be shut in using the annular, the drill pipe positioned relative to 

the annular, and the annulus isolated. The internal barrier in the Drill Pipe is a downhole check 

valve near the bit and a surface-mounted valve. These barriers will contain the influx and any 

associated build-up of surface pressure. It will also prevent further influx of formation fluid into 

the wellbore. 

To kill an influx, surface pressures will be allowed to stabilize and then the SIDP (Shut In Drill 

Pipe) and SICP (Shut In Casing Pressure) are measured. These pressures will enable the 
Petrobras America Inc. Page B-5 

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

calculation of the new kill-weight mud density needed to regain primary well control. A 

standard well-kill procedure will be implemented to circulate the kill-weight mud and safely 

remove formation fluids from the hole. Mud-gas separators and degassers will be used to safely 

remove gas from the mud as it is circulated out of the hole. After this procedure is completed, 

the kill effectiveness will be confirmed and the well will be circulated around, the BOPE opened 

up and the fluid levels monitored. Drilling operations will resume when the well has been 

brought under control and a static condition exists. 

Included as Attachment B-1, is Nodal Analysis data. 
Petrobras America Inc. Page C-1 

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

APPENDIX C 

GEOLOGICAL AND GEOPHYSICAL INFORMATION 

(A) GEOLOGICAL DESCRIPTION 

Proprietary Information. 

(B) STRUCTURE CONTOUR MAPS

Proprietary Information. 

(C) INTERPRETED 3-D SEISMIC LINE(S) 

Proprietary Information. 

(D) GEOLOGICAL STRUCTURE CROSS-SECTIONS

Proprietary Information. 

(E) SHALLOW HAZARDS REPORT

A shallow hazards survey was concluded in October 2010 on Walker Ridge Block 376 by 

Gardline Surveys, Inc. on behalf of PAI. 

Three copies of the shallow hazards report are being submitted to BOEM under separate cover. 

(F) SHALLOW HAZARDS ASSESSMENT 

Utilizing the 3D seismic exploration data, a shallow hazards assessment was prepared for the 

proposed surface locations, and is included as Attachment C-4. 

(G) HIGH-RESOLUTION SEISMIC LINES

Proprietary Information. 

 (H) STRATIGRAPHIC COLUMN

Proprietary Information. 

(I) TIME VS DEPTH TABLES

Proprietary Information. 
Petrobras America Inc Gardline Report 8570

Well Clearance Letter – Ipanema Prospect – Proposed WR376-A, B, C, D and E Well Locations

Public Shallow Hazards Statement – WR376-A

June 3, 2011

US Department of the Interior

Bureau of Ocean Energy Management, Regulation and Enforcement

1201 Elmwood Park Blvd.

New Orleans, LA 70213-2394

Attention: 

Reference: Shallow Hazards Analysis

Walker Ridge Block 376

(OCS-G 33375)

Ladies/Gentlemen:

Petrobras America Inc contracted Gardline Surveys, Inc. to prepare a Well Clearance Letter for the 

proposed WR376-A well location in Block 376, Walker Ridge Area (OCS-G 33375). This letter 

addresses seafloor and shallow geologic conditions that may impact exploratory drilling operations 

within 2,000ft of the proposed well location. The depth limit of this geohazard assessment is to Top of 

Salt at -7,971ft below sea surface (-1,413ft below seabed).

This hazards summary letter is issued as a supplement to Gardline Report No. 8570 entitled: 3D 

Geohazard Assessment, Gulf of Mexico, Walker Ridge Block 376, Ipanema Prospect, dated October 

2010.

Seabed Hazards. The seabed is rugose at the well location with faults to the north and the south;

none of the faults affect the proposed WR376-A well location.

There are no indications of seabed fluid seeps within 2,000ft of the well location.

No existing seabed infrastructure is located in the area.

Sub-Seabed Hazards. The proposed well location crosses a fault plane at the level of Horizon H20.

An anomaly interpreted as a High Risk of Gas and a Moderate Shallow Water Flow Risk is present 

within Unit C.
Petrobras America Inc Gardline Report 8570

Well Clearance Letter – Ipanema Prospect – Proposed WR376-A, B, C, D and E Well Locations

Proposed WR376-A Location (Surface)

Location Coordinates

NAD 27 Datum - Clarke 1866 Ellipsoid UTM Zone 15N - CM 90° West

Latitude 26° 34' 39.85” North Easting 2,364,337 US ft E

Longitude 90° 47’ 4.64” West Northing 9,650,279 US ft N

FWL of Walker Ridge 376 4,177 US ft Inline 7463

FSL of Walker Ridge 376 3,719 US ft Crossline 37821

Water Depth: -6,558 ft Slope: 3° southwest

Nearest Shoreline 169 Miles @ 0° 18’ 00”

Port of Operation Fourchon 176 Miles @ 10° 40’ 12”

Nearest Manned Platform A-Constitution in GC680 50.38 Miles @ 347° 10’ 00”

Conclusions and Recommendations. A pilot hole is planned to be drilled to the level of the 

interpreted risk of gas within Unit C to quantify the exact level of risk for this well location.

Sincerely,

Petrobras America Inc

Luis Gasparotto

Regulatory Specialist

PUBLIC INFORMATION
Petrobras America Inc Gardline Report 8570

Well Clearance Letter – Ipanema Prospect – Proposed WR376-A, B, C, D and E Well Locations

Public Shallow Hazards Statement – WR376-B

June 3, 2011

US Department of the Interior

Bureau of Ocean Energy Management, Regulation and Enforcement 

1201 Elmwood Park Blvd

New Orleans, LA 70213-2394

Attention: 

Reference: Shallow Hazards Analysis

Walker Ridge Block 376

(OCS-G 33375)

Ladies/Gentlemen:

Petrobras America Inc contracted Gardline Surveys, Inc. to prepare a Well Clearance Letter for the 

proposed WR376-B well location in Block 376, Walker Ridge Area (OCS-G 33375). This letter 

addresses seafloor and shallow geologic conditions that may impact exploratory drilling operations 

within 2,000ft of the proposed well location. The depth limit of this geohazard assessment is to Top of 

Salt at -8,159ft below sea surface (-1,472ft below seabed).

This hazards summary letter is issued as a supplement to Gardline Report No. 8570 entitled: 3D 

Geohazard Assessment, Gulf of Mexico, Walker Ridge Block 376, Ipanema Prospect, dated October 

2010.

Seabed Hazards. The seabed is rugose with faults to the north and the south of the proposed well 

location. None of these features directly affect the proposed WR376-B well location.

There are no indications of seabed fluid seeps within 2,000ft of the well location.

No existing seabed infrastructure is located in the area.

Sub-Seabed Hazards. 

The proposed well location crosses two fault planes near Horizons H10 and H30. Well design will 

consider these faults.

No shallow gas or shallow water flow is anticipated.
Petrobras America Inc Gardline Report 8570

Well Clearance Letter – Ipanema Prospect – Proposed WR376-A, B, C, D and E Well Locations

Proposed WR376-B Location (Surface)

Location Coordinates

NAD 27 Datum - Clarke 1866 Ellipsoid UTM Zone 15N - CM 90° West

Latitude 26° 34' 26.26” North Easting 2,365,554 US ft E

Longitude 90° 46’ 51.50” West Northing 9,648,927 US ft N

FWL of Walker Ridge 376 5,394 US ft Inline 7481

FSL of Walker Ridge 376 2,367 US ft Crossline 37817

Water Depth: -6,687 ft Slope: 4.5° SSE

Nearest Shoreline 168 Miles @ 0° 18’ 00”

Port of Operation Fourchon 176 Miles @ 10° 40’ 12”

Nearest Manned Platform A-Constitution in GC680 50.78 Miles @ 346° 49’ 00”

Conclusions and Recommendations. Well design will consider the two fault intersections.

Sincerely,

Petrobras America Inc

Luis Gasparotto

Regulatory Specialist

PUBLIC INFORMATION
Petrobras America Inc Gardline Report 8570

Well Clearance Letter – Ipanema Prospect – Proposed WR376-A, B, C, D and E Well Locations

Public Shallow Hazards Statement – WR376-C & D

June 6, 2011

US Department of the Interior

Bureau of Ocean Energy Management, Regulation and Enforcement 

1201 Elmwood Park Blvd.

New Orleans, LA 70213-2394

Attention: 

Reference: Shallow Hazards Analysis

Walker Ridge Block 376

(OCS-G 33375)

Ladies/Gentlemen:

Petrobras America Inc contracted Gardline Surveys, Inc. to prepare a Well Clearance Letter for the 

proposed WR376-C & D well location in Block 376, Walker Ridge Area (OCS-G 33375). This letter 

addresses seafloor and shallow geologic conditions that may impact exploratory drilling operations 

within 2,000ft of the proposed well location. The depth limit of this geohazard assessment is to Top of 

Salt at -8,084ft below sea surface (-1,492ft below seabed).

This hazards summary letter is issued as a supplement to Gardline Report No. 8570 entitled: 3D 

Geohazard Assessment, Gulf of Mexico, Walker Ridge Block 376, Ipanema Prospect, dated October 

2010.

Seabed Hazards. The seabed is rugose with faults to the north and to the south. None of these 

features directly affect the proposed WR376-C & D well location.

There are no indications of seabed fluid seeps within 2,000ft of the well location.

No existing seabed infrastructure is located in the area.

Sub-Seabed Hazards. 

There is a negligible to slight risk of encountering shallow gas and or shallow water flow at the level of 

the sand interbed within Unit C.
Petrobras America Inc Gardline Report 8570

Well Clearance Letter – Ipanema Prospect – Proposed WR376-A, B, C, D and E Well Locations

Proposed WR376-C & D Location (Surface)

Location Coordinates

NAD 27 Datum - Clarke 1866 Ellipsoid UTM Zone 15N - CM 90° West

Latitude 26° 34' 34.07” North Easting 2,365,460 US ft E

Longitude 90° 46’ 52.38” West Northing 9,649,715 US ft N

FWL of Walker Ridge 376 5,300 US ft Inline 7475

FSL of Walker Ridge 376 3,155 US ft Crossline 37841

Water Depth: -6,592 ft Slope: 9.14° southeast

Nearest Shoreline 169 Miles @ 0° 18’ 00”

Port of Operation Fourchon 176 Miles @ 10° 40’ 12”

Nearest Manned Platform A-Constitution in GC680 50.56 Miles @ 347° 1’ 48”

Conclusions and Recommendations. Drilling caution will be exercised at the level of the sand 

interbed within Unit C.

Sincerely,

Petrobras America Inc

Luis Gasparotto

Regulatory Specialist

PUBLIC INFORMATION
Petrobras America Inc. Page D-1 

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

APPENDIX D 

HYDROGEN SULFIDE INFORMATION 

(A) CONCENTRATION 

PAI does not anticipate encountering any H2S during the proposed operations. 

(B) CLASSIFICATION

In accordance with Title 30 CFR 250.490(c), PAI requests that Walker Ridge Block 376 be 

classified by the BOEM as H2S absent. 
Petrobras America Inc. Page E-1

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

APPENDIX E 

BIOLOGICAL, PHYSICAL AND SOCIOECONOMIC INFORMATION 

(A) DEEPWATER BENTHIC COMMUNITIES 

Activities proposed in this EP will disturb seafloor areas in water depths of 300 meters (984 feet) 

or greater; therefore, information as outlined in Attachment A of NTL No. 2009-G40, 

"Deepwater Benthic Communities", is provided below. PAI will avoid all high-density 

deepwater benthic communities by 2,000 feet from each proposed mud and cuttings discharge 

location and 250 feet from the location of all other seafloor disturbances. 

MAPS

Attached to this EP is a map prepared using 3-D seismic data depicting seafloor and shallow 

geological features and areas, and the surface locations of the proposed wells with a radius circle 

of 2000 feet around each well. This map is included as Attachment E-1. 

ANALYSIS

Walker Ridge Block 376 well locations A, B, D: 

Using 3-D seismic information, all seafloor features and areas that could be disturbed by the 

activities proposed in this plan have been identified. The likelihood of these proposed activities 

disturbing these seafloor and shallow geologic features is discussed in the following summary: 

Well Locations A, B, D: Features or areas that could support high-density deepwater benthic 

communities are not located within 2000 feet of any proposed muds and cuttings discharge 

location. The statement letters for the proposed wells are included as Attachment E-2. 

(B) TOPOGRAPHIC FEATURES MAP 

Activities proposed in this EP do not fall within 305 meters (1000 feet) of a topographic “no 

activity zone”. 

(C) TOPOGRAPHIC FEATURES STATEMENT (SHUNTING) 

All activities proposed under this EP will be conducted outside all Topographic Feature 

Protective Zones; therefore, shunting of drill cuttings and drilling fluids is not required 

(D) LIVE BOTTOMS (PINNACLE TREND) MAP 

Walker Ridge Block 376 is not located within 61 meters (200 feet) of any pinnacle trend feature; 

therefore, a separate bathymetric map is not required. 

(E) LIVE BOTTOMS (LOW RELIEF) STIPULATION 

Walker Ridge Block 376 is not located within 100 feet of any pinnacle trend feature with vertical 

relief equal to or greater than 8 feet; therefore, live bottom (low relief) maps are not required. 

(F) POTENTIALLY SENSITIVE BIOLOGICAL FEATURES 

Walker Ridge Block 376 is not located within 61 meters (200 feet) of potentially sensitive 

biological features; therefore, biologically sensitive area maps are not required. 
Petrobras America Inc. Page E-2

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

(G) REMOTELY OPERATED VEHICLE (ROV) SURVEYS 

BOEM has determined that there is enough data gathered in Grid Area 11; therefore, we will not 

be conducting any ROV surveys either pre-spud or post-drilling operations for the purpose of 

biological and physical observation. 

(H)THREATENED AND ENDANGERED SPECIES, CRITICAL HABITAT, AND MARINE 

MAMMAL INFORMATION 

Under Section 7 of the Endangered Species Act (ESA) all federal agencies must ensure that any 

actions they authorize, fund, or carry out are not likely to jeopardize the continued existence of a 

listed species, or destroy or adversely modify its designated critical habitat. 

In accordance with 30 CFR 550, Subpart B, and further outlined in NTL 2008-G04, 

lessees/operators are required to address site-specific information on the presence of federally 

listed threatened or endangered species and critical habitat designated under the ESA and marine 

mammals protected under the Marine Mammal Protection Act (MMPA) in the area of proposed 

activities under this plan. 

There are five species of sea turtles that may be found in the Gulf of Mexico (see table below). 

NOAA fisheries currently lists all five of these turtles as endangered (E) or threatened (T). 

Species Scientific Name Status 

Potential Presence 

Critical Habitat Designated 

in the Gulf of Mexico Lease Area Coastal 

Sea Turtles 

Loggerhead Turtle Carettsa Caretta T x x None 

Green Turtle Chelonia mydas T,E x x None

Leatherback Turtle Dermochelys corlacea E x x None

Hawksbill Turtle Eretmochelys imbricata E x x None

Kemp’s Ridley Turtle Lepidochelys kempli E x x None

In addition, there are 28 species of marine mammals that may be found in the Gulf of 

Mexico. The table provided below identifies the seven (7) species of marine mammals that are 

listed as endangered or threatened. Currently, there are no designated critical habitats for the 

listed species in the Gulf of Mexico Outer Continental Shelf; however, it is possible that one or 

more of these species could be seen in the area during operations. 

Species Scientific Name Status

Potential Presence Critical Habitat 

Designated in the Gulf 

of Mexico

Lease 

Area Coastal

Marine Mammals

Sperm Whale Physeter macrocephalus E X -- None

Florida Manatee Trichechus manatus latirostris E -- x Florida (Peninsular)

Blue Whale Balaenoptera masculus E X -- None

Fin Whale Balaenoptera physalus E X -- None

Humpback Whale Megaptera novaeangliae E X -- None

North Atlantic Right Whale Eubalaena glacialis E X -- None

Sei Whale Balaenopiera borealis E X -- None
Petrobras America Inc. Page E-3

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

(I) ARCHAEOLOGICAL REPORT 

Walker Ridge Block 376 is not located in an area determined to have any historic or prehistoric 

cultural resources. 

(J) AIR AND WATER QUALITY INFORMATION 

Air and water quality information is not required by BOEM to be included in this plan. 

(K) SOCIOECONOMIC INFORMATION 

Not applicable to this plan. 
Walker Ridge Block 331 (OCS-G27383) Walker Ridge Block 332 (OCS-G27384) Walker Ridge Block 333 (OCS-G27385)

Walker Ridge Block 375 (OCS-G26394) Walker Ridge Block 376 (OCS-G33375) Walker Ridge Block 377 (OCS-G33376)

Walker Ridge Block 419 (Not Leased) Walker Ridge Block 420 (OCS-G32680) Walker Ridge Block 421 (Not Leased)

2,000ft Radius

2,000ft Radius

2,000ft Radius

2,000ft Radius

Proposed WR376-E (Surface Location in WR420)

7450

7500

7400

7550

7350

7600

7300

7650

7250

38101

37909

38293

37717

38485

37525

38677

37333

38869

37141

39061

-6575

-6600

-6550

-6625

-6650

-6675

-6700

-6725

-6750

-6525

-6775

-6800

-6500

-6825

-6850

-6875

-6900

-6925

-6950

-6975

-7000

-6475

-7025

-7050

-7075

-6450

-7100

-7125

-7150

-7175

-7200

-7225

-7250

-7275

-7300

-7325

-7350

-6425

-7375

-7400

-6400

-7425

-6375

-7450

-7475

-7500

-7525

-7550

-6350

-6325

-6300

-6275

-6250

-6225

-6500

-6350

-6625

-6425

-6675

-6600

-6575

-6400

-6500

-6525

-6675

-6650

-6700

-6300

-6775

-6500

-6550

-6500

-6575

-6675

-6600

-6575

-6700

-6800

-6550

-6825

-6725

-6625

-6625

-6775

-6475

-6275

-6300

-6425

-6600

-6275

-6850

-6450

-6325

-6525

-6575

-6625

-6375

-6750

-6725

-6325

-6375

-6550

-6600

-6575

-6700

-6600

-6900

-6650

-6650

-6750

-6600

-6950

-6725

-6725

-6400

-6625

-6625

-6650

-6700

-6525

-6525

-6475

-6650

-6650

-6775

-6675

-6725

-6875

-6550

-6925

-6350

Proposed WR376-C & D

Proposed WR376-B

Proposed WR376-A

2,360,0002,370,0002,380,000

9,640,000

9,650,000

9,660,000

9,670,000

90°49'30"W90°48'0"W90°46'30"W90°45'0"W90°43'30"W

26°37'30"N

26°36'0"N

26°34'30"N

26°33'0"N

Lund Henderson

Lloyd Ridge

Walker Ridge

Green Canyon Atwater Valley Garden Banks

Keathley Canyon

Florida Plain

East Breaks

Lund South

Mississippi Canyon De Soto Canyon

Study Area

LEGEND

Chart Scale 1" = 1,000'

GEODETIC INFORMATION

Datum Parameters

Datum Name

Ellipsoid

Semi-major Axis

Reciprocal Flattening

NAD 1927

Clarke 1866

6378206

294.9786

Projection Method

False Northing

False Easting

Latitude of Origin

Longitude of Origin

Standard Parallel

Scale Factor

Transverse Mercator

0

1640416.66

0 North

93 East

15 North

0.9996

SEABED COMPOSITE

CHART 6

0 1,000 2,000 3,000 4,000 5,000 6,000 500 Feet

0 300 600 900 1,200 1,500 1,800 150 Meters

Depth in feet below sea surface to seabed,

contoured at 25ft intervals

Relative seabed amplitude

REV DATE REMARKS AUTHOR DRAWN CHECKED

SURVEY DATE N/A REPORT REF 8570 REF NO 8570.06

Not to scale

±

Prepared by: Gardline Surveys, Inc. 1500 Bingle Road, Houston, Texas, 77055. Telephone: 713.481.4630

Notes

Map Projection Parameters

-6900

Region of seabed favorable for the development 

of sensitive sessile benthic communities

Seabed fault intersection, tick denotes 

downthrown block

Area of seabed slumping

2,000ft Well Location Exclusion Zone

around potential sensitive sites

No depth conversion was required as the 3D seismic data was supplied by Petrobras as a depth converted volume

1 November 22, 2010 DRAFT - NAD27 JR DP ARH

2 December 6, 2010 DRAFT - REVISED INLINES AND 

CROSSLINES

JR DP ARH

3 FINAL JR DP ARH

Inline

Crossline

Block boundaries

Study area boundary

Proposed WR376-B Well Location

2,365,554ft E / 9,648,927ft N

Proposed WR376-C & D Well Location

2,365,460ft E / 9,649,715ft N

Proposed WR376-E Well Location

(with a Surface Location in WR420)

2,362,221ft E / 9,645,771ft N

3® 3

3

3

3® 3

3

3

3® 3

3

3

3® 3

3

3

Proposed WR376-A Well Location

2,364,337ft E / 9,650,279ft N

3D GEOHAZARD ASSESSMENT

GULF OF MEXICO

WALKER RIDGE

BLOCK 376

IPANEMA PROSPECT

June 3, 2011
Petrobras America Inc Gardline Report 8570

Well Clearance Letter – Ipanema Prospect – Proposed WR376-A, B, C, D and E Well Locations

Sensitive Sessile Benthic Community Statement – WR376-A

Petrobras America Inc

June 3, 2011

US Department of the Interior

Bureau of Ocean Energy Management, Regulation and Enforcement

1201 Elmwood Park Blvd.

New Orleans, LA 70213-2394

Reference: Sensitive Sessile Benthic Community Summary

Walker Ridge, Block 376

(OCS-G 33375)

Ladies/Gentlemen:

Gardline Surveys Inc was contracted by Petrobras America Inc to prepare a Site Clearance Letter for 

the proposed WR376-A well location in Walker Ridge, Block 376, Ipanema Prospect (OCS-G 33375). 

This letter addresses location proximity to potential sensitive sessile benthic community sites. 

Petrobras America Inc will be drilling this well from a dynamically positioned drilling module; therefore,

no anchors will impact seabed.

This sensitive sessile benthic community summary letter is issued as a supplement to Gardline Report 

No. 8570 entitled: 3D Geohazard Assessment, Gulf of Mexico, Walker Ridge Block 376, Ipanema

Prospect, dated October 2010. A Biological, Physical and Socio-Economic Figure and Map are

included at the end of this appendix illustrating the areas of potential seabed impact.

Potential Sensitive Sessile Benthic Communities. 

Features or areas that could support high density sensitive sessile benthic communities are not 

located within 2,000ft of any proposed mud and cuttings discharge location.
Petrobras America Inc Gardline Report 8570

Well Clearance Letter – Ipanema Prospect – Proposed WR376-A, B, C, D and E Well Locations

Proposed WR376-A Location (Surface)

Location Coordinates

NAD 27 Datum - Clarke 1866 Ellipsoid UTM Zone 15N - CM 90° West

Latitude 26° 34' 39.85” North Easting 2,364,337 US ft E

Longitude 90° 47’ 4.64” West Northing 9,650,279 US ft N

FWL of Walker Ridge 376 4,177 US ft Inline 7463

FSL of Walker Ridge 376 3,719 US ft Crossline 37821

Water Depth: -6,558 ft Slope: 3° southwest

Nearest Shoreline 169 Miles @ 0° 18’ 00”

Port of Operation Fourchon 176 Miles @ 10° 40’ 12”

Nearest Manned Platform A-Constitution in GC680 50.38 Miles @ 347° 10’ 00”

Nearest potential sensitive sessile benthic community to the proposed location is a localized 

fluid expulsion site 2,801ft WNW of the proposed well location.

Conclusions and Recommendations: The proposed WR376-A well location will not impact any 

sites favourable for development of sensitive sessile benthic communities.

Sincerely,

Petrobras America Inc

Luis Gasparotto

Regulatory Specialist
Petrobras America Inc Gardline Report 8570

Well Clearance Letter – Ipanema Prospect – Proposed WR376-A, B, C, D and E Well Locations

Sensitive Sessile Benthic Community Statement – WR376-B

Petrobras America Inc

June 3, 2011

US Department of the Interior

Bureau of Ocean Energy Management, Regulation and Enforcement

1201 Elmwood Park Blvd.

New Orleans, LA 70213-2394

Reference: Sensitive Sessile Benthic Community Summary

Walker Ridge, Block 376

(OCS-G 33375)

Ladies/Gentlemen:

Gardline Surveys Inc was contracted by Petrobras America Inc to prepare a Site Clearance Letter for 

the proposed WR376-B well location in Walker Ridge, Block 376, Ipanema Prospect (OCS-G 33375). 

This letter addresses location proximity to potential sensitive sessile benthic community sites. 

Petrobras America Inc will be drilling this well from a dynamically positioned drilling module; therefore,

no anchors will impact seabed.

This sensitive sessile benthic community summary letter is issued as a supplement to Gardline Report 

No. 8570 entitled: 3D Geohazard Assessment, Gulf of Mexico, Walker Ridge Block 376, Ipanema

Prospect, dated October 2010. A Biological, Physical and Socio-Economic Figure and Map are 

included at the end of this appendix illustrating the areas of potential seabed impact.

Potential Sensitive Sessile Benthic Communities. 

Features or areas that could support high density sensitive sessile benthic communities are not 

located within 2,000ft of any proposed mud and cuttings discharge location.
Petrobras America Inc Gardline Report 8570

Well Clearance Letter – Ipanema Prospect – Proposed WR376-A, B, C, D and E Well Locations

Proposed WR376-B Location (Surface)

Location Coordinates

NAD 27 Datum - Clarke 1866 Ellipsoid UTM Zone 15N - CM 90° West

Latitude 26° 34' 26.26” North Easting 2,365,554 US ft E

Longitude 90° 46’ 51.50” West Northing 9,648,927 US ft N

FWL of Walker Ridge 376 5,394 US ft Inline 7481

FSL of Walker Ridge 376 2,367 US ft Crossline 37817

Water Depth: -6,687 ft Slope: 4.5° SSE

Nearest Shoreline 168 Miles @ 0° 18’ 00”

Port of Operation Fourchon 176 Miles @ 10° 40’ 12”

Nearest Manned Platform A-Constitution in GC680 50.78 Miles @ 346° 49’ 00”

Nearest potential sensitive sessile benthic community to the proposed location is a localized 

fluid expulsion site 4,315ft WNW of the proposed well location.

Conclusions and Recommendations: The proposed WR376-B well location will not impact any 

sites favourable for development of sensitive sessile benthic communities.

Sincerely,

Petrobras America Inc

Luis Gasparotto

Regulatory Specialist
Petrobras America Inc Gardline Report 8570

Well Clearance Letter – Ipanema Prospect – Proposed WR376-A, B, C, D and E Well Locations

Proposed WR376-C & D Location (Surface)

Location Coordinates

NAD 27 Datum - Clarke 1866 Ellipsoid UTM Zone 15N - CM 90° West

Latitude 26° 34' 34.07” North Easting 2,365,460 US ft E

Longitude 90° 46’ 52.38” West Northing 9,649,715 US ft N

FWL of Walker Ridge 376 5,300 US ft Inline 7475

FSL of Walker Ridge 376 3,155 US ft Crossline 37841

Water Depth: -6,592 ft Slope: 9.1° southeast

Nearest Shoreline 169 Miles @ 0° 18’ 00”

Port of Operation Fourchon 176 Miles @ 10° 40’ 12”

Nearest Manned Platform A-Constitution in GC680 50.56 Miles @ 347° 1’ 48”

Nearest potential sensitive sessile benthic community to the proposed location is a localized 

fluid expulsion site 4,000ft WNW of the proposed well location.

Conclusions and Recommendations: The proposed WR376-C & D well location will not impact any 

sites favourable for development of sensitive sessile benthic communities.

Sincerely,

Petrobras America Inc

Luis Gasparotto

Regulatory Specialist
Petrobras America Inc Gardline Report 8570

Well Clearance Letter – Ipanema Prospect – Proposed WR376-A, B, C, D and E Well Locations

Sensitive Sessile Benthic Community Statement – WR376-C & D

Petrobras America Inc

June 3, 2011

US Department of the Interior

Bureau of Ocean Energy Management, Regulation and Enforcement

1201 Elmwood Park Blvd.

New Orleans, LA 70213-2394

Reference: Sensitive Sessile Benthic Community Summary

Walker Ridge, Block 376

(OCS-G 33375)

Ladies/Gentlemen:

Gardline Surveys Inc was contracted by Petrobras America Inc to prepare a Site Clearance Letter for 

the proposed WR376-C & D well location in Walker Ridge, Block 376, Ipanema Prospect (OCS-G 

33375). This letter addresses location proximity to potential sensitive sessile benthic community sites. 

Petrobras America Inc will be drilling this well from a dynamically positioned drilling module; therefore,

no anchors will impact seabed.

This sensitive sessile benthic community summary letter is issued as a supplement to Gardline Report 

No. 8570 entitled: 3D Geohazard Assessment, Gulf of Mexico, Walker Ridge Block 376, Ipanema

Prospect, dated October 2010. A Biological, Physical and Socio-Economic Figure and Map are 

included at the end of this appendix illustrating the areas of potential seabed impact.

Potential Sensitive Sessile Benthic Communities. 

Features or areas that could support high density sensitive sessile benthic communities are not 

located within 2,000ft of any proposed mud and cuttings discharge location.
±

3® 3

3

3

3® 3

3

3

3® 3

3

3

3® 3

3

3

-6550

-6525

-6450

-6475

-6500

-6575

-6425

-6600

-6625

-6400

-6650

-6675

-6375

-6700

-6725

-6750

-6775

-6350

-6800

-6825

-6850

-6325

-6875

-6900

-6925

-6300

-6950

-6275

-6575

-6650

-6625

-6275

-6750

-6825

-6375

-6300

-6450

-6550

-6875

-6475

-6425

-6600

-6775

-6325

-6525

-6425

-6550

-6575

-6500

-6400

-6675

-6725

-6375

-6850

-6600

-6700

-6625

-6400

-6350

-6575

-6800

-6900

Proposed WR376-C & D

Proposed WR376-B

Proposed WR376-A

Proposed WR376-E (Surface Location in WR420)

90°48'0"W90°47'0"W90°46'0"W

26°35'0"N

26°34'0"N

2,360,0002,365,0002,370,000

9,645,000

9,650,000

9,655,000

0 1,000 2,000 500 Feet

0 250 500 125 Meters

Chart scale 1" = 2,000'

Biological, Physical & Socio-Economic Plat

Proposed WR376-A Well Location

2,364,337ft E / 9,650,279ft N 3® 3

3

3

Proposed WR376-B Well Location

2,365,554ft E / 9,648,927ft N 3® 3

3

3

Depth in feet below sea surface to seabed,

contoured at 25ft intervals

-6400

BLOCK WR376 (OCS-G33375)

Proposed WR376-C & D Well Location

2,365,460ft E / 9,649,715ft N 3® 3

3

3

Block boundary

Proposed WR376-E Well Location

(with a Surface Location in WR420)

2,362,221ft E / 9,645,771ft N

3® 3

3

3

BLOCK WR420 (OCS-G32680)

2,000ft Radius

2,000ft Radius

2,000ft Radius

2,000ft Radius

Seabed fault intersection, tick denotes 

downthrown block

Region of seabed favorable for the development 

of sensitive sessile benthic communities

2,000ft Well Location Exclusion Zone

around potential sensitive sites
Petrobras America Inc. Page F-1 

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

APPENDIX F 

WASTES AND DISCHARGES INFORMATION 

(A) PROJECTED GENERATED WASTES 

Table 1, “Wastes You Will Generate, Treat and Downhole Dispose or Discharge to the GOM”

is included in this section as Attachment F-1. 
Type of Waste Composition Projected Amount Discharge rate Discharge Method 

Water-based drilling fluid Continuous phase and suspending medium for solids is water miscible fluid 16000 bbls per well 500 bbls per hour per well Discharged overboard with or at seabed (pri

marine riser installation); no free oil 

Cuttings wetted with water-based fluid

Particles generated by drilling into geologic formationsadhering to water based drilling fluids 2000 bbls per well 15 bbls per hour per well Discharged overboard or at seabed (prior to 

riser installation); no free oil 

Cuttings wetted with syntheticbased fluid Particles generated by drilling into geologic formations adhering to synthetic based drilling fluids (internal olefin) 7200 bbls per well 15 bbls per hour per well Discharged overboard line from cuttings dry

free oil 

Domestic waste Discharge from galleys, sinks, and showers 210,000 gallons per month 50 gallons per day per person Discharge overboard; no floating solids Sanitary waste Human body waste from toilets and urinals 126,000 gallons per month 30 gallons per day per person Discharge overboard; no floating solids Deck Drainage Deck washing and rain water

3,000 bbls per month (dependent on rainfall)

100 bbls per day (dependent on rainfall)

Discharge overboard; no free oil 

Well treatment fluids XL Boraite 7500 bbls per well 400 bbls per well Discharge overboard; no free oil 

Well completion fluids NA NA NA NA 

Workover fluids NA NA NA NA Desalinization unit discharge Chemically treated seawater associated with making fresh water from seawater 145,000 blls per month < 100 BBls per day (dependent on use) Discharge overboard; no free oil Blowout preventer fluid Stack Magic at 3% (95% water and 2% glycol) 300 bbls per well 55 bbls per month Subsea discharge 

Ballast water Ballast water returned to sea without addition of chemicals 45,000 bbls per month 1,000 bbls per hour Discharge overboard; no free oil 

Bilge water Bilge water returned to sea without addition of chemicals 2,000 bbls per month 10 bbls per hour Oily water discharge then discharge overboa

free oil 

Excess cement at seafloor Discharges that occur at seabed prior to installation of marine riser 35000 bbls per well 400 bbls per hour per well Discharged at seabed (prior to marine riser installation); no free oil Seawater Uncontaminated Seawater 90,000 bbls per month 125 bbls per hour Discharge overboard; no free oil Fire water included in seawater above NA NA NA Cooling water NA NA NA NA Produced water NA NA NA NA 

Attachment F-1. WASTES GENERATED, TREATED AND DISPOSED OR DISCHARGED TO THE GOM BY DRILLING RIG

Will you be covered by an individual or general NPDES permit ? YES

Projected generated waste Projected ocean discharges 
Petrobras America Inc. Page G-1 

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

APPENDIX G 

AIR EMISSIONS INFORMATION 

(A) EMISSIONS WORKSHEETS AND SCREENING QUESTIONS 

 Screen Procedures for EP’s 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 

There are no existing facilities or activities co-located with the currently proposed activities; 

therefore, the Complex Total Emissions are the same as the Plan Emissions and are provided in 

the table below. 

Air Pollutant 

Plan 

Emission 

Amounts1

(tons) 

Calculated 

Exemption 

Amounts2

(tons) 

Calculated 

Complex Total 

Emission 

Amounts3

(tons) 

Carbon Monoxide (CO) 573.34 103,928.99 573.34 

Particular Matter (PM) 76.45 5,627.70 76.45 

Sulphur Dioxide (SO2) 350.69 5,627.70 350.69 

Nitrogen Oxides (NOx) 2,627.82 5,627.70 2,627.82 

Volatile Organic Compounds (VOC) 78.83 5,627.70 78.83 

1

For activities proposed in your EP, list the projected emissions calculated from the worksheets. 2

List the exemption amounts for your proposed activities calculated by using the formulas in 30 CFR 550.303(d). 3

List the complex total emissions associated with your proposed activities calculated from the worksheets. 

This information was calculated by: Judy Davidson 

 (281) 578-3388 

 Judy.Davidson@jccteam.com
Petrobras America Inc. Page H-1 

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

APPENDIX H 

OIL SPILLS INFORMATION 

(A) OIL SPILL RESPONSE PLANNING 

All the proposed activities and facilities in the Exploration Plan will be covered by the Oil Spill 

Response Plan (OSRP) approved dated March 12, 2012. PAI (BOEM Operator No. 01207) 

submitted the last modification to the Plan filed on March 7, 2012, and was approved on March 

12, 2012. 

(B) SPILL RESPONSE SITES 

Primary Response Equipment Location Preplanned Staging Location 

Houma, LA 

Harvey, LA 

Venice, LA 

Houma, LA 

Harvey, LA 

Venice, LA 

(C) OSRO INFORMATION 

PAI’s primary equipment provider is Clean Gulf Associates (CGA). The Marine Spill Response 

Corporation’s (MSRC) STARS network will provide closest available personnel, as well as an 

MSRC supervisor to operate the equipment. PAI has a non-member agreement with MWCC for 

well containment for Walker Ridge Block 376. 

(D) WORST-CASE SCENARIO COMPARISON 

Category Regional OSRP 

WCD 

EP 

WCD 

Type of Activity Drilling Drilling 

Facility Location 

(Area/Block) WR 376 WR 376 

Facility Designation B B 

Distance to Nearest 

Shoreline (miles) 169 169 

Volume 

 Storage Tanks (Total) 

Uncontrolled blowout 

Total Volume 

43,595 43,595 

Type of Oil(s) 

(Crude, Condensate, 

Diesel) 

Crude Crude 

API Gravity 26° 26° 
Petrobras America Inc. Page H-2 

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

PAI has determined that the worst-case scenario from the activities proposed in this EP does 

supersede the worst-case scenario from our approved Regional OSRP. 

PAI’s OSRP was revised to indicate the new worst-case discharge and has been submitted for 

approval on March 7, 2012 and was approved on March 12, 2012. 

As a member of CGA, PAI has the capability to respond, to the maximum extent practicable, to 

the worst-case discharge, or a substantial threat of such a discharge, resulting from the activities 

proposed in this EP. 

(E) SPILL RESPONSE DISCUSSION FOR NEPA ANALYSIS 

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 43,595 barrels of crude oil with an API gravity of 26°. 

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 BSEE Oil Spill Risk Analysis Model (OSRAM) for the Central and 

Western Gulf of Mexico available on the BSEE website. The results are shown in Figure 1. The 

BSEE OSRAM identifies a 2% probability of impact to the shorelines in Galveston County, 

Texas, Cameron Parish, Louisiana, and Plaquemines Parish, Louisiana within 30 days. 

Galveston County includes the Gulf Beach from the west end of Galveston Island at Texas 

Highway 3005 to the east coast of High Island at the Jefferson County line. Habitats include 

marshes at the west end of Seawall Boulevard and on the east end of the island and open beaches 

and avian feeding areas all along the coastline, including a National Audubon Society Sanctuary. 

The waters of Galveston Bay are classified as an EPA National Estuary. 

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. 

Plaquemines Parish includes Barataria Bay, the Mississippi River Delta, Breton Sound and the 

affiliated islands and bays. This region is an extremely sensitive habitat and serves as a 

migratory, breeding, feeding and nursery habitat for numerous species of wildlife. Beaches in 

this area vary in grain particle size and can be classified as fine sand, shell or perched shell 

beaches. Sandy and muddy tidal flats are also abundant. 
Petrobras America Inc. Page H-3 

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

Response 

Petrobras America Inc. will make every effort to respond to the Worst Case Discharge as 

effectively as practicable. A description of the response equipment under contract 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 13% or 

approximately 5,667 barrels of crude oil would be evaporated/dispersed within 24 hours, with 

approximately 37,928 barrels remaining. 

Spill Response WR 376 B Barrels of Oil 

WCD Volume 43,595 

Less 13% natural evaporation/dispersion 5,667 

Remaining volume 37,928 

Daily dispersant capability 7,540 

Oil addressed by in-situ burning 1,896 

Figure 2 outlines equipment, personnel, materials and support vessels as well as temporary 

storage equipment available to respond to a spill of approximately 37,928 barrels. The volume 

accounts for the amount remaining after evaporation/dispersion at 24 hours. 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. 

Petrobras America Inc.’s Oil Spill Response Plan includes alternative response technologies such 

as dispersants and in-situ burn. Strategies will be decided by Unified Command based on size of 

the spill, weather and potential impacts. 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 would 

provide a daily dispersant capability of 7,540 barrels. 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 approximately 1,896 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 nine Fast Response Units (FRUs), with a total derated skimming capacity of 76,930 barrels. 

Temporary storage associated with skimming equipment equals 5,700 barrels. If additional 

storage is needed, a 25,000 barrel storage barge and a 47,000 barrel storage barge 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. 
Petrobras America Inc. Page H-4 

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

If the spill went unabated, shoreline impacts in Cameron Parish, Louisiana or Plaquemines 

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 13,253 barrels. Temporary storage associated with skimming equipment 

equals 1,252 barrels. If additional storage is needed, two 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. Onshore response may include the deployment of 

shoreline boom on beach areas, or protection and sorbent boom on vegetated areas. Letters of 

Intent from Oil Mop and AMPOL ensure access to 137,000 feet of 18” shoreline protection 

boom. Figure H.3 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 either Cameron Parish or Plaquemines 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. Petrobras 

America Inc.’s contract Spill Management Team holds a copy of the State of Louisiana Initial 

Oil Spill Response Plan. 

If the spill went unabated, shoreline impact in Galveston County, Texas 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 13,253 barrels. 

Temporary storage associated with skimming equipment equals 1,252 barrels. If additional 

storage is needed, two 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. Onshore response may include the deployment of shoreline boom on beach areas, or 

protection and sorbent boom on vegetated areas. A Letter of Intent from Oil Mop will ensure 

access to 18” shoreline protection boom. Booming operations for protection of major inlets and 

sensitive areas of Galveston County, Texas will be completed using the Site Specific Response 

Sheets and plans in the Houston/Galveston Area Contingency Plan. Currently this ACP provides 

booming strategies for several areas in the county but does not detail boom requirements except 

in rare cases. Figure H.3 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 One-Gulf Plan 

(Area Contingency Plan) 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. Each response mode is schematically represented to 

show optimum deployment and operation of the equipment in areas of environmental concern. 
Petrobras America Inc. Page H-5 

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

Supervisory personnel have the option to modify the deployment and operation of equipment 

allowing a more effective response to site-specific circumstances. Petrobras America Inc.’s 

contract Spill Management Team holds a copy of the One-Gulf Plan. 

Based on the anticipated worst case discharge scenario, Petrobras America Inc. can be onsite 

with contracted oil spill recovery equipment with adequate response capacity to contain and 

recover surface hydrocarbons, and prevent land impact, to the maximum extent practicable, 

within an estimated 50 hours (based on the equipment’s Effective Daily Recovery Capacity 

(EDRC)). Petrobras America Inc. will continue to commit additional on-water mechanical 

recovery resources as well as apply dispersants and in-situ burning needed and as approved, 

under the supervision of the USCG Captain of the Port (COTP) and the Regional Response 

Team (RRT). 
Petrobras America Inc. Page H-6 

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

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 

Petrobras America 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. 

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 

 
Petrobras America Inc. Page H-7 

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

Dispersant application assets 

 Put ASI on standby 

 With the FOSC, conduct analysis to determine appropriateness of dispersant application 

 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 

 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 

 
Petrobras America Inc. Page H-8 

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

Vessels of Opportunity (VOO) 

 Use Petrobras America 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 
Petrobras America Inc. Page H-9 

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

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 Petrobras America 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 

 Operate with aerial spotter directing systems to oil patches 
Petrobras America Inc. Page H-10 

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

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 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 

 
Petrobras America Inc. Page H-11 

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

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 

 
Petrobras America Inc. Page H-12 

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

Environmental Conditions in the GOM

Prevailing winds, waves and currents along the Texas coast are from the southeast and northeast 

quadrants. Ten to 20 foot waves may occur during hurricanes. The combined effect of the 

winds, surface currents, and waves refracting shoreward produce the prevailing westerly 

longshore currents. 

Tides are semi-diurnal and diurnal, and range in height from less than 1 foot to 2.5 feet. The 

direction, force, and duration of the wind has a considerable effect on the tides and currents. 

Fifteen foot tides may be expected during severe hurricanes and very low tides may accompany 

strong northerlies of long duration. 

Surface water temperature averages slightly less than 90° F and ranges between 80 and 100° F 

during the late summer. During the winter the average is slightly less than 60° F and the range is 

between 35 and 80° F. 

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. 

 
Petrobras America Inc. Page H-13 

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

FIGURE 1 

TRAJECTORY BY LAND SEGMENT 

Trajectory of a spill and the probability of it impacting a land segment have been projected 

utilizing Petrobras America Inc.’s WCD and information in the BSEE Oil Spill Risk 

Analysis Model (OSRAM) for the Central and Western Gulf of Mexico available on the 

BSEE 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 

Drill, Complete, Test 

and TA 3 Wells 

WR 376 B 

169 miles from shore 

G33375 C48 Matagorda County, TX 

Brazoria County, TX 

Galveston County, TX 

Jefferson County, TX 

Cameron Parish, LA 

Vermilion Parish, LA 

Terrebonne Parish, LA 

Lafourche Parish, LA 

Plaquemines Parish, LA 

1 

1 

2 

1 

2 

1 

1 

1 

2 
Petrobras America Inc. 

Initial Exploration Plan Walker Ridge 376 (OCS-G 33375)WCD Scenario– BASED ON WELL BLOWOUT DURING DRILLING OPERATIONS (169 miles from s37,928 bbls of crude oil (Volume considering natural weathering) 

API Gravity 26° 

FIGURE 2 – Equipment Response Time to WR 376 B 

Dispersant/Surveillance 

Dispersant/Surveillance Dispersant Capacity (gal) Storage Capacity Persons Req. From Hrs to Procure Hrs to Loadout Travel to s

CGA 

Basler 67T 2000 NA 2 Houma 1 1 1.1 

ASI 

DC 3 1200 NA 2 Houma 1 1 1.5 DC 3 1200 NA 2 Houma 1 1 1.5 Aero Commander NA NA 2 Houma 1 1 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

Sp

CGA

HOSS Barge 43000 4000 3 Tugs 8 Harvey 7 0 5 

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 contract with CGA)

CTCo 2603 NA 25000 1 Tug 6 Amelia 4 12 4 CTCo 5001 NA 47000 1 Tug 6 Amelia 4 12 4 
Petrobras America Inc. 

Initial Exploration Plan Walker Ridge 376 (OCS-G 33375)Staging Area: Venice 

Offshore Equipment With 

Staging EDRC Storage Capacity VOO Persons Req. From Hrs to Procure Hrs to Loadout Travel to Staging 

CGA

FRU (1) + 100 bbl Tank (2) 3770 200 1 Utility 6 Belle Chasse 1 2 2 FRU (1) + 100 bbl Tank (2) 3770 200 1 Utility 6 Galveston 1 2 8 FRU (3) + 100 bbl Tank (5) 11310 500 1 Utility 6 Houma 1 2 3 FRU (1) + 100 bbl Tank (2) 3770 200 1 Utility 6 Ingleside 1 2 11 FRU (1) + 100 bbl Tank (2) 3770 200 1 Utility 6 Lake Charles 1 2 5.5 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 (5000’) NA NA 10 Crew 20 Galveston 1 2 8 42” Auto Boom (5000’) NA NA 10 Crew 20 Houma 1 2 3 42” Auto Boom (2500’) NA NA 6 Crew 12 Ingleside 1 2 11 42” Auto Boom (5000’) NA NA 10 Crew 20 Lake Charles 1 2 5.5 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 
Petrobras America Inc. 

Initial Exploration Plan Walker Ridge 376 (OCS-G 33375)

Nearshore Response 

Nearshore 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 contract with CGA) 

CTCo 2604 NA 20000 1 Tug 6 Amelia 4 12 4 CTCo 2606 NA 20000 1 Tug 6 Amelia 4 12 4 

Staging Area: Venice 

Nearshore and Inland 

Skimmers With Staging EDRC Storage Capacity VOO Persons Req. From Hrs to Procure Hrs to Loadout Travel to Staging Tr

Dep

CGA

SWS Egmopol 3000 100 NA 3 Galveston 1 2 8 SWS Egmopol 3000 100 NA 3 Houma 1 2 3 SWS Marco 3588 34 NA 3 Houma 1 2 3 SWS Marco 3588 20 NA 3 Lake Charles 1 2 5.5 Rope Mop 77 2 0 3 Belle Chasse 1 2 2 RO Storage Barge NA 249 Towed 0 Galveston 1 2 8 RO Storage Barge NA 249 Towed 0 Houma 1 2 3 RO Storage Barge NA 249 Towed 0 Lake Charles 1 2 5.5 RO Storage Barge NA 249 Towed 0 Venice 1 2 0 
Petrobras America Inc. 

Initial Exploration Plan Walker Ridge 376 (OCS-G 33375)

Shoreline Protection 

Staging Area: Venice 

18” Shoreline Protection 

Boom VOO Persons Req. Storage/Warehouse Location Hrs to Procure Hrs to Loadout Travel to Staging Travel to Deployment 

Oil Mop (available through Letter of Intent)

10,000’ 18” Boom 4 Crew 10 New Iberia, LA 1 1 4 2 10,000’ 18” Boom 4 Crew 10 Port Arthur, TX 1 1 6.25 2 20,000’ 18” Boom 8 Crew 20 Belle Chasse, LA 1 1 1.75 2 10,000’ 18” Boom 4 Crew 10 Port Allen, LA 1 1 3.5 2 10,000’ 18” Boom 4 Crew 10 Houma, LA 1 1 3.5 2 15,000’ 18” Boom 6 Crew 14 Gretna, LA (Warehouse) 2 2 2 2 

AMPOL (available through Letter of Intent) 

42,000’ 18” Boom 16 Crew 40 New Iberia, LA 2 2 4 2 20,000’ 18” Boom 8 Crew 20 New Orleans, LA 2 2 2 2 

Beach Boom EDRC Storage Capacity VOO Persons Req. From Hrs to Procure Hrs to Loadout Travel to Staging Tr

Dep

CGA

Beach Boom (2000’) NA NA NA 6 Galveston 1 2 8 Beach Boom (1000’) NA NA NA 4 Ingleside 1 2 11 Beach Boom (2000’) NA NA NA 6 Pascagoula 1 2 4 
Petrobras America Inc. 

Initial Exploration Plan Walker Ridge 376 (OCS-G 33375)

Wildlife Response EDRC Storage Capacity VOO Persons Req. From Hrs to Procure Hrs to Loadout Travel to Staging Tr

Dep

CGA

Wildlife Support Trailer NA NA NA 2 Houma 1 2 3 Bird Scare Guns (24) NA NA NA 2 Belle Chasse 1 2 2 Bird Scare Guns (12) NA NA NA 2 Galveston 1 2 8 Bird Scare Guns (24) NA NA NA 2 Houma 1 2 3 Bird Scare Guns (12) NA NA NA 2 Ingleside 1 2 11 Bird Scare Guns (24) NA NA NA 2 Lake Charles 1 2 5.5 Bird Scare Guns (24) NA NA NA 2 Pascagoula 1 2 4 

Response Asset Total 

Offshore EDRC 76,930 Offshore Recovered Oil Storage 77,700 Nearshore / Shallow Water EDRC 13,253 Nearshore / Shallow Water Recovered Oil Storage 41,252 
Petrobras America Inc. Page I-1 

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

APPENDIX I 

ENVIRONMENTAL MONITORING INFORMATION 

(A) MONITORING SYSTEMS 

PAI will operate in accordance with NTL 2009-G02, using ADCP arrays to gather ocean current 

data for all floating MODU’s in water depths greater than 1,312 feet. 

Monitoring and testing per Region 6 NPDES General Permit requirements will be completed. 

Monitoring and reporting applicable statistics to the BOEM and the BSEE Gulf of Mexico 

Region (GOMR) regarding evacuation. 

(B) INCIDENTAL TAKES 

There is no reason to believe that any of the endangered species or marine mammals as listed in 

the ESA will be “taken” as a result of the operations proposed under this plan. 

To date, it has been documented that the use of explosives and/or seismic devices can affect 

marine life. Operations proposed in this plan will not be utilizing either of these devices. 

(C) FLOWER GARDEN BANKS NATIONAL MARINE SANCTUARY 

Walker Ridge Block 376 is not located in the Flower Garden Banks National Marine Sanctuary; 

therefore, the requested information is not required in this EP. 
Petrobras America Inc. Page J-1 

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

APPENDIX J 

LEASE STIPULATIONS INFORMATION 

Exploration activities are subject to the following stipulation attached to Lease OCS-G 33375 

Walker Ridge Block 376. 

Marine Protected Species 

Lease Stipulation No. 8 is meant to reduce the potential taking of marine protected species. PAI 

will operate in accordance with NTL 2007-G04, to minimize the risk of vessel strikes to 

protected species and report observations of injured or dead protected species, and the prevention 

of intentional and/or accidental introduction of debris into the marine environment.
Petrobras America Inc. Page K-1 

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

APPENDIX K 

ENVIRONMENTAL MITIGATION MEASURES INFORMATION 

(A) MEASURES TAKEN TO AVOID, MINIMIZE, AND MITIGATE IMPACTS 

Not applicable to this plan. 

(B) INCIDENTAL TAKES

PAI will adhere to the requirements as set forth in the following documents, as applicable, to 

avoid or minimize impacts to any of the species listed in the ESA as a result of the operations 

conducted herein: 

 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” 
Petrobras America Inc. Page L-1 

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

APPENDIX L 

SUPPORT VESSELS AND AIRCRAFT INFORMATION 

(A) GENERAL

The most practical, direct route from the shorebase as permitted by weather and traffic 

conditions will be utilized. 

Type 

Maximum Fuel 

Tank Capacity 

Maximum Number 

in Area at Any 

Time 

Trip 

Frequency or 

Duration 

Offshore Service Vessel 

(PSV) 8,900 bbls 3 2 roundtrips/week 

Fast Supply Vessel 

 (FSV) / Crew Boat 800 bbls 2 3 roundtrips/week 

Helicopters 267 gals. 1 1 roundtrip/day 

(B) DIESEL OIL SUPPLY VESSELS 

Size of Fuel Supply 

Vessel 

Capacity of Fuel 

Supply Vessel 

Frequency of Fuel 

Transfers 

Route Fuel Supply 

Vessel Will Take 

180’ 8,900 bbls 2 Round trips / week 

Shortest route from 

Port Fourchon, LA to 

Walker Ridge Block 

376. 

*Please note the actual vessels have not yet been contracted. 

(C) VICINITY MAP 

Enclosed as Attachment L-2 is a vicinity map showing the location of the activities proposed 

herein relative to the shoreline with the distance of the proposed activities from the shoreline and 

the primary route(s) of the support vessels and aircraft that will be used when traveling between 

the onshore support facilities and the drilling unit. 

 
Solid and Liquid Wastes 

transportation 

Type of Waste Composition Transport Method Name/Location of Facility Amount 

Oil-based drilling fluid or mud NA NA NA NA Synthetic-based drilling fluid or mud 

 Continuous phase of the drilling fluid is a synthetic material

Tanks or drums on offshore support vessels

US Liquids (Port Fourchon, LA) or Newpark Services (Port Fourchon, LA)

750 bbls per well 

Cuttings wetted with Water-based fluid NA NA NA NA Cuttings wetted with Synthetic-based fluid NA NA NA NA Cuttings wetted with oil-based fluids NA NA NA NA Produced sand NA NA NA NA Trash and debris

Non-hazardous garbage, trash, and debris that can not be recycled

Containers on offshore support vessels Waste Management (Raceland, LA) One standar

container peweek 

Used oil Lube oils (maintenance) Drums on offshore support vessels Martin (Port Fourchon, LA0-1 bbl per week 

Wash water NA NA NA NA Chemical product wastes NA NA NA NA 

Waste Disp

Attachment L-1. WASTES YOU WILL TRANSPORT AND /OR DISPOSE OF ONSHORE FROM DRILLING RIGS

Projected generated waste
!!

!!

!!

!!

!!

!!

!! !!

Green Canyon

Walker Ridge Lund

Ship Shoal

Atwater Valley

South Timbalier

Mississippi Canyon

Eugene Island

Ewing Bank

West Delta

Ship Shoal South

Grand Isle

South Timbalier South

West Delta South

South Pelto

Fourchon

Cocodrie

Grand Isle

River Ridge

Terrebonne Lafourche

Plaquemines

Jefferson

Petrobras America, Inc. Vicinity Map

Walker Ridge 376

WR376

~16

9

Mile

s to

S

h

ore

~

1

77

Miles

to

Fou

rchon, LA

Shorebase
Petrobras America Inc. Page M-1 

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

APPENDIX M 

ONSHORE SUPPORT FACILITIES INFORMATION 

(A) GENERAL 

Name of Shorebase Location Existing/New/Modified 

Fourchon Service Base Port Fourchon, Louisiana Existing 

MI Drilling Fluids Port Fourchon, Louisiana Existing 

(B) SUPPORT BASE CONSTRUCTION OR EXPANSION

There will be no new construction of an onshore support base, nor will we expand the existing 

shorebase as a result of the operations proposed in this Exploration Plan. 

(C) WASTE DISPOSAL 

Table 2, “Wastes You Will Transport and/or Dispose of Onshore” is included in Appendix L as 

Attachment L-1.
Petrobras America Inc. Page N-1 

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

APPENDIX N 

COASTAL ZONE MANAGEMENT (CZMA) INFORMATION 

Relevant enforceable policies were considered in certifying consistency for Louisiana. A 

certificate of Coastal Zone Management Consistency for the state of Louisiana is enclosed as 

Attachment N-1. 

Petrobras America Inc. Page O-1 

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

APPENDIX O 

ENVIRONMENTAL IMPACT ANALYSIS (EIA) 

Petrobras America Inc. (PAI) 

Initial Exploration Plan 

Walker Ridge Block 376 

OCS-G 33375 

(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 

Fisheries 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(6) 

Marine and pelagic birds X X 

Public health and safety (5) 

Coastal and Onshore 

Beaches X(6) X 

Wetlands X(6) 

Shore birds and coastal nesting 

birds 

 X6) 

Coastal wildlife refuges 

Wilderness areas 
Petrobras America Inc. Page O-2 

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

Footnotes for Environmental Impact Analysis Matrix 

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: 

4-mile zone of the Flower Garden Banks, or the 3-mile zone of Stetson Bank; 

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; 

Essential Fish Habitat (EFH) criteria of 500 ft. from any no-activity zone; or 

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. 

Activities with any bottom disturbance within an OCS lease block protected through the Live Bottom (Pinnacle Trend) 

Stipulation attached to an OCS lease. 

Activities within any Eastern Gulf OCS block where seafloor habitats are protected by the Live Bottom (Low-Relief) 

Stipulation attached to an OCS lease. 

Activities on blocks designated by the BOEM as being in water depths 300 meters or greater. 

Exploration or production activities where H2S concentrations greater than 500 ppm might be encountered. 

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. 

All activities that involve seafloor disturbances, including anchor emplacements, in any OCS block designated by the 

BOEM 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. 

All activities that you determine might have an adverse effect on endangered or threatened marine mammals or sea turtles 

or their critical habitats. 

Production activities that involve transportation of produced fluids to shore using shuttle tankers or barges. 
Petrobras America Inc. Page O-3 

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

(B) Analysis 

Site-Specific at Walker Ridge Block 376 

Proposed operations consist of the drilling, completion and potential testing of three locations (A, B 

and D). 

The operations will be conducted with a drill ship. 

1. Designated Topographic Features 

Potential IPFs on topographic features include effluents, and accidents. 

Effluents: Walker Ridge Block 376 is 102.5 miles from the closest designated Topographic Features 

Stipulation Block (Diaphus Bank and Ewing-1 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 PAI’s Regional OSRP (refer to information submitted in Appendix H). 

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 impact topographic features. 

2. Pinnacle Trend Area Live Bottoms 

Potential IPFs on pinnacle trend area live bottoms include effluents and accidents. 

Effluents: Walker Ridge Block 376 is 228 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 
Petrobras America Inc. Page O-4 

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

to the distance of these blocks from a live bottom (pinnacle trend) area. The activities proposed in this 

plan will be covered by PAI’s Regional OSRP (refer to information submitted in Appendix H). 

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 impact a live bottom (pinnacle trend) area. 

3. Eastern Gulf Live Bottoms 

Potential IPFs on Eastern Gulf live bottoms include effluents and accidents. 

Effluents: Walker Ridge Block 376 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 PAI’s Regional 

OSRP (refer to information submitted in Appendix H). 

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 impact an Eastern Gulf live bottom area. 

4. Benthic Communities 

There are no IPFs (including emissions, physical disturbances to the seafloor, wastes sent to shore for 

disposal, or accidents) from the proposed activities that could cause impacts to benthic communities. 

Although Walker Ridge Block 376 is located in water depths exceeding 984 feet (300 meters), a drill 

ship is being used for the proposed activities; therefore, only an insignificant amount of seafloor will 

be disturbed. Because physical disturbances to the seafloor will be minimized by the use of a drill 

ship, PAI’s proposed operations in Walker Ridge Block 376 would not cause impacts to benthic 

communities. 

5. Water Quality 

IPFs that could result in water quality degradation from the proposed operations in Walker Ridge 

Block 376 include effluents and accidents. 

 
Petrobras America Inc. Page O-5 

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

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 of oil are insoluble in water and therefore float. The activities proposed in this 

plan will be covered by PAI’s Regional Oil Spill Response Plan (refer to information submitted in 

Appendix H). 

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 Walker Ridge Block 

376 include effluents and accidents. 

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 down-current 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 PAI’s Regional OSRP (refer to information submitted in 

Appendix H). 
Petrobras America Inc. Page O-6 

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

There are no IPFs from emissions, physical disturbances to the seafloor 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 cause impacts to 

marine mammals as a result of the proposed operations in Walker Ridge Block 376 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). 

PAI 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 PAI management or 
Petrobras America Inc. Page O-7 

Initial Exploration Plan November, 2011 

Walker Ridge 376 (OCS-G 33375)

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 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 Marine Mammal Stranding Network at (305) 862-

2850. In addition, if the injury or death was caused by a collision with a contract vessel, the BOEM 

must be notified within 24 hours of the strike by email to protectedspecies@boemre.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 PAI’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 PAI’s OSRP (refer to information submitted in accordance with Appendix H). 

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. 
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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). 

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). PAI 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 PAI 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 Marine Mammal 

Stranding Network at (305) 862-2850. In addition, if the injury or death was caused by a collision with 

a contract vessel, the BOEM must be notified within 24 hours of the strike by email to 

protectedspecies@boemre.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 
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add to the possibility of collisions with sea turtles. The activities proposed in this plan will be covered 

by PAI’s Regional Oil Spill Response Plan (refer to information submitted in accordance with 

Appendix H). 

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. Walker Ridge Block 376 is beyond the 200 kilometer 

(124 mile) buffer for the Breton Wilderness Area and is 168 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 Walker Ridge Block 376 

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) 

Potential IPFs that could impact known or unknown shipwreck sites as a result of the proposed 

operations in Walker Ridge Block 376 include disturbances to the seafloor. 

Physical disturbances to the seafloor: A drill ship is being used for the proposed activities; 

therefore, only an insignificant amount of seafloor will be disturbed. Because physical disturbances to 

the seafloor will be minimized by the use of a drill ship, PAI’s proposed operations in Walker Ridge 

Block 376 would not cause impacts to shipwreck sites. 

Additionally, Walker Ridge Block 376 is not located in or adjacent to an OCS block designated by 

BOEM as having a high probability for occurrence of shipwrecks, therefore, no adverse impacts are 

expected. 

PAI will perform an ROV survey imaging 100% of the seafloor with sector scanning sonar within a 

minimum 500’ radius of the proposed well location(s) prior to or upon commencement of operations. 

These locations will be certified by an authorized marine archaeologist and by PAI 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 BOEM. Should a resource be encountered, 

PAI will contact the BOEM immediately and make every reasonable effort to preserve and protect that 

cultural resource. 
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There are no other IPFs (including emissions, effluents, wastes sent to shore for treatment or disposal, 

or accidents) from the proposed activities that could cause impacts to shipwreck sites. 

11. Prehistoric Archaeological Sites 

Potential IPFs that could cause impacts to prehistoric archaeological sites as a result of the proposed 

operations in Walker Ridge Block 376 include disturbances to the seafloor. 

Physical disturbances to the seafloor: A drill ship is being used for the proposed activities; 

therefore, only an insignificant amount of seafloor will be disturbed. Because physical disturbances to 

the seafloor will be minimized by the use of a drill ship, PAI’s’ proposed operations in Walker Ridge 

Block 376 would not cause impacts to prehistoric archaeological sites. 

PAI will perform an ROV survey imaging 100% of the seafloor with sector scanning sonar within a 

minimum 500’ radius of the proposed well location(s) prior to or upon commencement of operations. 

These locations will be certified by an authorized marine archaeologist and by PAI to be clear of 

seafloor archaeological resources. Copies of the certifications and a circle radius plat of the survey 

area will be submitted to the BOEM. Should a resource be encountered, PAI will contact the BOEM 

immediately and make every reasonable effort to preserve and protect that cultural resource. 

Additionally, Walker Ridge Block 376 is located outside the Archaeological Prehistoric high 

probability line, therefore, no adverse impacts are expected. 

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 prehistoric archeological 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 Walker Ridge Block 

376 include effluents and accidents. EFH includes all estuarine and marine waters and substrates in the 

Gulf of Mexico. 

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 livebottom 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 
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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 PAI’s’ Regional OSRP (refer to information submitted in Appendix H). 

There are no other IPFs (including emissions, physical disturbances to the seafloor and 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. 

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 PAI’s’ Regional 

OSRP (refer to information submitted in Appendix H). 

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 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). PAI 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 servicesrelated 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 
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marine trash and debris training video annually. Offshore personnel will also receive an explanation 

from PAI 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 release) 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 D to justify our request that 

our proposed activities be classified by BSEE as H2S absent. 

Coastal and Onshore 

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 (168 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 PAI’s’ Regional OSRP (refer to information submitted in Appendix H). 

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). PAI 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. 
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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 PAI 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 

IPFs from the proposed activities that could cause impacts to wetlands include accidents (oil spills) and 

discarded trash and debris. 

Accidents: 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 (168 miles) and the response capabilities that would be 

implemented, no impacts are expected. The activities proposed in this plan will be covered by PAI’s’ 

Regional OSRP (refer to information submitted in Appendix H). 

Discarded trash and debris: 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). PAI 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 PAI management or 

the designated lease operator management that emphasizes their commitment to waste management in 

accordance with NTL No. 2007-G03. 
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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 (168 miles) and the response capabilities that would be implemented, no 

impacts are expected. The activities proposed in this plan will be covered by PAI’s’ Regional OSRP 

(refer to information submitted in Appendix H). 

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). PAI 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 vessels and every facility that has sleeping or food 

preparation capabilities. All offshore personnel, including contractors and other support servicesrelated 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 PAI 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 (168 miles) and the response capabilities that would 

be implemented, no impacts are expected. The activities proposed in this plan will be covered by 

PAI’s’ Regional OSRP (refer to information submitted in Appendix H). 
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Discarded trash and debris: Operators are prohibited from deliberately discharging debris as 

mandated by MARPOL-Annex V, 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). PAI 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 servicesrelated 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 PAI 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 coastal 

wildlife refuges. 

5. Wilderness Areas 

Accidents: 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 nearest designated Wilderness Area (218 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 PAI’s’ Regional OSRP (refer to information 

submitted in Appendix H).

Discarded trash and debris: Operators are prohibited from deliberately discharging debris as 

mandated by MARPOL-Annex V, 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). PAI 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-
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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 PAI 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 wilderness 

areas. 

6. Other Environmental Resources Identified 

There are no other environmental resources identified for this impact assessment. 

(C) IMPACTS ON 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, Walker Ridge Block 376 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: 

1. Drilling & completion 

a. Secure well 

b. Secure rig / platform 

c. Evacuate personnel 

Drilling activities will be conducted in accordance with NTL No.’s 2008-G09, 2009-G10, and 2010-

N10. 

2. Structure Installation 

 Operator will not conduct structure installation operations during Tropical Storm or 

 Hurricane threat. 
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(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) 

Matt Harlan 

J. Connor Consulting, Inc. 

16225 Park Ten Place, Suite 700 

Houston, TX 77084 

(281) 578-3388 

matt.harlan@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. 

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-TMNMFS-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. 
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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. 

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 FieldNaturalist. 89:278-298. 

Although not cited, the following were utilized in preparing this EIA: 

Hazard Surveys 

BOEM EIS’s: 

GOM Deepwater Operations and Activities. Environmental Assessment. BOEM 2000-001 

GOM Central and Western Planning Areas Sales 166 and 168 Final Environmental Impact 

Statement. BOEM 96-0058 
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APPENDIX P 

ADMINISTRATIVE INFORMATION 

(A) EXEMPTED INFORMATION DESCRIPTION 

The proposed bottom-hole locations of the planned wells have been removed from the public 

information copy of the EP as well as any discussions of the target objectives, geologic or geophysical 

data, and any interpreted geology. 

(B) BIBLIOGRAPHY 

Not applicable.