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 Da te: May 15, 2012

Authorized Representative: No. Copies Being Submitted: Melissa Flack or Judy Davids on 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 Nu mber 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 E xploration Plan, PAI proposes to drill and complete three wells, Locations A, B and D. The wells will be dril led with a drillship. Water depths across the bloc k 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 Inform ation Form. Rig specifications will be made part of each Appli cation 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 includ e well control, pollution prevention, and blowout prevention equipment as described in 30 CFR Pa rt 250, Subparts C, D, E, O and S; and as further clarified by BOEM/BSEE Notices to Le ssees, 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 INFO RMATION 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) Deve lopment 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 activ ities 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 Barg e (If anchor radius supp lied 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 Ac t 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 vali d Office of Management and Budget Control Number. The use of th is form is voluntary. The public reporting burden for this form is included in the burden for preparing Exploration Plans a nd 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, ga thering 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 O fficer, 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 Barg e (If anchor radius supp lied 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 Ac t 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 vali d Office of Management and Budget Control Number. The use of th is form is voluntary. The public reporting burden for this form is included in the burden for preparing Exploration Plans a nd 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, ga thering 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 O fficer, 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 structur e, 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 Barg e (If anchor radius supp lied 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 Ac t 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 vali d Office of Management and Budget Control Number. The use of th is form is voluntary. The public reporting burden for this form is included in the burden for preparing Exploration Plans a nd 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, ga thering 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 O fficer, Bureau of Ocean Energy Management, 381 Elden Street, Herndon, VA 20170.

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### 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/a pplications 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 (inter nal 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 facili ties 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 Ge neral Lease Surety Bonds;" and additional security under 30 CFR 256.53(d) and Natio nal NTL No. 2008-N07, “Supplemental Bond Procedures.”

(E) OIL SPILL FINANCIAL RESPONSIBILITY (OSFR) Petrobras America Inc., BOEM company numb er 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 Re sponsibility (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 othe r 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 declin e. 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 wellbor e 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 de sign in conjunction with actual pore pressure, actual fluids and actual fracture gr adients 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 desi gn 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 We lls / Estimated Blowout Duration: Should surface intervention prove unsuccessful, PAI has evaluated two additional potential scenarios to kill a blowout; seaflo or 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 fl ow 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 para llel with this operation, a rig will be mobilized (approximately 20 deepwater rigs capable of this water depth an d hook loads currently work in the GOM) to drill a relief well, estimated to be 14 days to contr act, 14 days to mobilize and 76 days to kill the well which would result in a total disc harge 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 blow out. The time range required for this purpose would be from a minimum of 65 days to a maxi mum 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 Reli ef Well / Rig Package Constraints: Should a relief well be required, a deepwater ri g currently located in the GOM would be contracted to drill the relief we ll. As of November 2010, there are approximately 20 rigs in the GOM capable of drilling an Ipanem a 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 ri g 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 commu nication to the subsea BOPE and an autoshear system to shut-in the well in the event of an ac cidental 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 we ll. 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 drill ing supervisors, operat ions 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 bl owout 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 inspecti on 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 te sting 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 comp letion reduces the likelihood of a blowout and relies on a number of interrelat ed 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 drill ing or completion operations. In the event that primary well control is lost, the BOPE will contai n 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, we ll shut-in, and circulating the ki cks out of the wellbore. Well specific shut-in procedures will be posted on the rig.

Well Control Monitoring and Procedures Automatic and manual monitoring e quipment will be installed to de tect 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 sp ecific 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 resu lt 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 formati on 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 hydro carbon), 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 intern al 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 pressu re. It will also prevent furthe r influx of formation fluid into the wellbore.

To kill an influx, surface pressures will be allowe d 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-weigh t mud density needed to rega in 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 se parators and degassers wi ll 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 ci rculated around, the BOPE opened up and the fluid levels monitore d. Drilling operations will re sume 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 sh allow 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

, 0 00ft of the proposed well location

. The depth limit of this geohazard assessment is to Top of
Salt at

- 7

, 9 71 ft below sea surface (

- 1

, 413 ft 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.

**Sea bed 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

, 0 00ft of the well location.

No existing s eabed 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 15 N

- CM 90° West

Latitude 26° 34 ' 39.85 ” North Easting 2,364,337 US ft E
Longitude 9 0 ° 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 5 0.38 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 INFORMATIONPetrobras 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 Blv d 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

, 159 ft below sea surface (

- 1, 4 72 ft below seabed).

This hazards summary letter is issued as a supplement to Gardline Report No. 8 570 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 directl y 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 loca tion crosses two faul t 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 15 N

- CM 90° West

Latitude 26° 34 ' 26.26 ” North Easting 2,365,554 US ft E
Longitude 9 0 ° 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 5 0.78 Miles @ 346° 49’ 00”

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

Sincerely,
Petrobras America Inc

Luis Gasparotto Regulatory Specialist



## PUBLIC INFORMATIONPetrobras 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 dril ling operations within 2,000ft of the proposed well location

. The depth limit of this geohazard assessment is to Top of
Salt at

- 8

, 08 4 ft below sea surface (

- 1, 49 2 ft below seabed).

This hazards summary letter is issued as a supplement to Gardline Report N o. 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 W R376

- 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 g as and or shallow water flow at the level of
the sand interbed with in 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 15 N

- CM 90° West

Latitude 26° 34 ' 34.07 ” North Easting 2,365,460 US ft E
Longitude 9 0 ° 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 5 0.56 Miles @ 347° 1’ 48”

**Conclusions and Recommendations.** Drilling caution will be exercised at the level of the sand
interbed with in 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 SULFID E INFORMATION

(A) CONCENTRATION PAI does not anticipate encountering any H 2 

### S 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 H 2 

### S absent.

### Petrobras America Inc. Page E- 1 Initial Exploration Plan November, 2011 Walker Ridge 376 (OCS-G 33375) APPENDIX E BIOLOGICAL, PHYSICAL AND SO CIOECONOMIC 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 ou tlined 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 locati ons 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 feat ures and areas that co uld be disturbed by the activities proposed in this plan have been identified. The like lihood of these proposed activities disturbing these seafloor and sh allow geologic features is disc ussed in the following summary:

Well Locations A, B, D: Features or areas th at could support high-density deepwater benthic communities are not located with in 2000 feet of any proposed muds and cuttings discharge location. The statement letters for th e proposed wells are included as Attachment E-2.

(B) TOPOGRAPHIC FEATURES MAP Activities proposed in this EP do not fall with in 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 an y pinnacle trend feature; therefore, a separate bathym etric map is not required.

(E) LIVE BOTTOMS (LOW RELIEF) STIPULATION Walker Ridge Block 376 is not loca ted within 100 feet of any pinna cle trend feature with vertical relief equal to or greater than 8 feet; therefore, live bottom (low relief) maps are not required.

(F) POTENTIALLY SENSITIV E BIOLOGICAL FEATURES Walker Ridge Block 376 is not located within 61 meters (200 feet) of potentially sensitive biological features; therefor e, 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 Ar ea 11; therefore, we will not be conducting any ROV surveys either pre-spud or post-drilling operations for the purpose of biological and physic al observation.

(H)THREATENED AND ENDANG ERED SPECIES, CRITICAL HABITAT, AND MARINE MAMMAL INFORMATION Under Section 7 of the Endangered Species Act (ESA) all federal ag encies must ensure that any actions they authorize, fund, or carry out are not li kely 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 informa tion on the presence of federally listed threatened or endangered species and criti cal habitat designated under the ESA and marine mammals protected under the Marine Mammal Pr otection 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 speci es of marine mammals that may be found in the Gulf of Mexico. The table provided below identifies the seven (7) species of ma rine mammals that are listed as endangered or threatene d. Currently, there are no design ated critical habitats for the listed species in the Gulf of Mexico Outer Contin ental 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 loca ted in an area determined to ha ve any historic or prehistoric cultural resources.

(J) AIR AND WATER QUALITY INFORMATION Air and water quality informati on 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

, 0 0

0

f t

R

a

d

i u

s 2

, 0 0

0

f t

R

a

d

i u

s

2

, 0 0

0

f t

R

a

d

i u

s 2

, 0 0

0

f t

R

a

d

i u

s

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-A2,360,0002,370,0002,380,000 9,640,000 9,650,000 9,660,000 9,670,00090°43'30"W90°45'0"W90°46'30"W90°48'0"W90°49'30"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 ®33 3

3

®33 3

3

®33 3

3

®33 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, 2011Petrobras 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 locat ion 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 summa ry 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

- E conomic Figure and Ma p are included at the e nd 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 15 N

- CM 90° West

Latitude 26° 34 ' 39.85 ” North Easting 2,364,337 US ft E
Longitude 9 0 ° 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 5 0.38 Miles @ 347° 10’ 00”

Nearest potential sensitive sessile benthic community to the proposed location is a localized fluid expulsion site 2

, 8 0 1 ft 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 SpecialistPetrobras 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, da ted 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 15 N

- CM 90° West

Latitude 26° 34 ' 26.26 ” North Easting 2,365,554 US ft E
Longitude 9 0 ° 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 5 0.78 Miles @ 346° 49’ 00”

Nearest potential sensitive sessile benthic community to the proposed location is a localized fluid expulsion site 4

, 3 15 ft 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 SpecialistPetrobras 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 15 N

- CM 90° West

Latitude 26° 34 ' 34.07 ” North Easting 2,365,460 US ft E
Longitude 9 0 ° 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 5 0.56 Miles @ 347° 1’ 48”

Nearest potential sensitive sessile benthic community to the proposed location is a localized fluid expulsion site 4

, 0 0 0 ft 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 SpecialistPetrobras 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 se ssile 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.

# ±

®33 3

3 ®33 3

3

®33 3

3 ®33 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°46'0"W90°47'0"W90°48'0"W

26°35'0"N

26°34'0"N2,360,0002,365,0002,370,000 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 ®33 3

3

Proposed WR376-B Well Location 2,365,554ft E / 9,648,927ft N ®33 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 ®33 3

3 Block boundary Proposed WR376-E Well Location (with a Surface Location in WR420) 2,362,221ft E / 9,645,771ft N ®33 3

3 

## BLOCK WR420 (OCS-G32680)

2

, 0 0 0 f t R

a d i u

s

2

, 0

0 0 f t R a d

i u

s

2

, 0

0 0 f t R a d

i u

s

2

, 0

0 0 f t R a d

i u

s

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 DISCHA RGES 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

.ProjectedDownholeDisposalType of Waste CompositionProjectedAmountDischarge rate Discharge MethodAnswer yes ornoWater-based drilling fluidContinuous phase and suspending medium for solids iswater miscible fluid16000 bbls perwell500 bbls perhour per wellDischarged overboard with or at seabed (prior tomarine riser installation); no free oilNoCuttings wetted with water-basedfluidParticles generated by drilling into geologic formationsadhering to water based drilling fluids2000 bbls per well15 bbls per hourper wellDischarged overboard or at seabed (prior to marineriser installation); no free oilNoCuttings wetted with syntheticbased fluidParticles generated by drilling into geologic formationsadhering to synthetic based drilling fluids (internalolefin)7200 bbls per well15 bbls per hourper wellDischarged overboard line from cuttings dryer; nofree oilNoDomestic wasteDischarge from galleys, sinks, and showers210,000 gallonsper month50 gallons perday per personDischarge overboard; no floating solidsNoSanitary wasteHuman body waste from toilets and urinals126,000 gallonsper month30 gallons perday per personDischarge overboard; no floating solidsNoDeck Drainage Deck washing and rain water3,000 bbls permonth (dependenton rainfall)100 bbls perday (dependenton rainfall)Discharge overboard; no free oilNoWell treatment fluids XL Boraite 7500 bbls per well400 bbls perwellDischarge overboard; no free oil NoWell completion fluidsNANA NANANoWorkover fluids NA NA NA NA NADesalinization unit dischargeChemically treated seawater associated with makingfresh water from seawater145,000 blls permonth< 100 BBls perday (dependenton use)Discharge overboard; no free oilNoBlowout preventer fluid Stack Magic at 3% (95% water and 2% glycol) 300 bbls per well55 bbls permonthSubsea discharge NABallast waterBallast water returned to sea without addition ofchemicals45,000 bbls permonth1,000 bbls perhourDischarge overboard; no free oilNoBilge waterBilge water returned to sea without addition ofchemicals2,000 bbls permonth10 bbls per hourOily water discharge then discharge overboard; nofree oilNoExcess cement at seafloorDischarges that occur at seabed prior to installation ofmarine riser35000 bbls perwell400 bbls perhour per wellDischarged at seabed (prior to marine riserinstallation); no free oilNoSeawaterUncontaminated Seawater90,000 bbls permonth125 bbls perhourDischarge overboard; no free oilNoFire water included in seawater above NA NA NA NACooling water NA NA NA NA NAProduced water NA NA NA NA NAAttachment F-1. WASTES GENERATED, TREATED AND DISPOSED OR DISCHARGED TO THE GOM BY DRILLING RIGWill you be covered by an individual or general NPDES permit ? YESProjected ocean dischargesProjected generated waste

### 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) Emis sion amount (tons) associated with your proposed exploration activities more than 90% of the amounts calculated using the following formulas: CT = 3400D 2/3 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 H 2 S 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 curre ntly proposed activities; therefore, the Complex Total Emissions are the sa me as the Plan Emissions and are provided in the table below.

Air Pollutant Plan Emission Amounts 1 (tons) Calculated Exemption Amounts 2 (tons) Calculated Complex Total Emission Amounts 3 (tons) Carbon Monoxide (CO) 573.34 103,928.99 573.34 Particular Matter (PM) 76.45 5,627.70 76.45 Sulphur Dioxide (SO 2 ) 350.69 5,627.70 350.69 Nitrogen Oxides (NO
x ) 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 ca lculated from the worksheets.

2 List the exemption amounts for your pr oposed activities calculat ed by using the formulas in 30 CFR 550.303(d).

3 List the complex total emissions associated with y our proposed activities calcul ated 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 f acilities in the Exploration Plan will be covered by the Oil Spill Response Plan (OSRP) approved dated Ma rch 12, 2012. PAI (BOEM Operator No. 01207) submitted the last modification to the Plan f iled on March 7, 2012, and was approved on March 12, 2012.

(B) SPILL RESPONSE SITES

Primary Response Equipment Loca tion 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-memb er 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 pr oposed in this EP does supersede the worst-case scenario from our approved Regional OSRP.

PAI’s OSRP was revised to indicate the new wo rst-case discharge and has been submitted for approval on March 7, 2012 and wa s 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, re sulting 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 Mana gement Act analysis, the largest spill volume originating from the proposed activity would be a well bl owout during drilling operations, estimated to be 43,595 barrels of crud e 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 BS EE 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% probabi lity of impact to the shorelines in Galveston County, Texas, Cameron Parish, Louisi ana, and Plaquemines Paris h, 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 a nd 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 cla ssified as an EPA National Estuary.

Cameron Parish includes the east side of Sa bine 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 Sabi ne 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, finf ish and other animals, including several rare, threatened and endangered species.

Plaquemines Parish includes Bara taria Bay, the Mississippi Rive r 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 de scription of the response equipmen t under contract to contain and recover the Worst Case Discharge is shown in Figure 2.

Using the estimated chemical and physical charact eristics of crude oil, an ADIOS weathering model was run on a similar product from the ADIO S 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 evaporatio n/dispersion at 24 hours. The list estimates individual times needed for proc urement, 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 Co mmand based on size of the spill, weather and potential impacts. If aerial dispersants are util ized, 8 sorties (9,600 gallons) from two of the DC-3 aircraft s and 4 sorties (8,000 gallons) from the Basler aircraft would provide a daily dispersant capab ility of 7,540 barrels. If the condi tions 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 to tal daily Worst Case Discharge volume could be burned. Slick containment boom would be imme diately 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 ba rge and a 47,000 barrel storage barge may be mobilized and centrally located to provide temporary storage allowi ng 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 prio r 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, shor eline impacts in Cameron Pari sh, Louisiana or Plaquemines Parish, Louisiana would depend upon existing environmental cond itions. 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 st orage 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 allowi ng the skimmers to stay in the area of operations as much as possible. On shore response may include the deployment of shoreline boom on beach areas, or protection a nd sorbent boom on vegetated areas. Letters of Intent from Oil Mop and AMPOL ensure acce ss to 137,000 feet of 18” shoreline protection boom. Figure H.3 outlines individual times needed for pr ocurement, 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 s ea 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 O il Spill Response Plan provides detailed shoreline protection strategies for this area, and it describes necessary action to k eep the oil spill from entering Louisiana’s coastal wetlands, base d 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 pe rsonnel have the option to modify the deployment and operation of equipment allowing a more effective respons e 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, s horeline impact in Galveston County, Texas would depend upon existing environmental conditions. Shoreline prot ection would include the use of CGA’s near shore and shallow water skimmers with a tota led derated skimming cap acity 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 de ployment of shoreline bo om 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 Count y, Texas will be completed us ing 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 c ounty but does not detail boom requirements except in rare cases. Figure H.3 outlines individual times needed for pr ocurement, load out, travel time to the site and deploymen t. Strategies would be based upon su rveillance and real time trajectories that depict areas of potential impact given actua l sea and weather conditi ons. The One-Gulf Plan (Area Contingency Plan) and Unified Comma nd would be consulted to ensure that environmental and special economic resources woul d be correctly identifie d and prioritized to ensure optimal protection. Shorel ine protection strategies depict the protection response modes applicable for oil spill clean-up operations. Each response mode is schema tically represented to show optimum deployment and operation of the e quipment in areas of e nvironmental 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-spe cific circumstances. Petrobras America Inc.’s contract Spill Management Team hol ds a copy of the One-Gulf Plan.

Based on the anticipated worst ca se discharge scenario, Petrobras America Inc. can be onsite with contracted oil spill recove ry equipment with adequate re sponse capacity to contain and recover surface hydrocarbons, and prevent land impact, to the maximum extent practicable, within an estimated 50 hours (based on the equi pment’s Effective Daily Recovery Capacity (EDRC)). Petrobras America Inc. will continue to commit additional on-water mechanical recovery resources as well as apply dispersa nts and in-situ burning needed and as approved, under the supervision of the USCG Captain of the Port (C OTP) 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, aggr essive response to contain and recover as much of the spilled oi l as quickly as it is safe to do so. In an effort to protect the environment, response actions wi ll 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 agen cies 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 situa tion and coordinated objectives

o Areas of responsibility esta blished for Source Control a nd each surface operational site

o On-site command and control established

Offshore Response Actions

Equipment Deployment Surveillance

 Surveillance Aircraft: within two hours of QI notificati on, or at first light

 Provide trained observer to pr ovide on site status reports

 Provide command and control platfo rm at the site if needed

 Continual surveillance of oil movement by re mote 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 determin e appropriateness of di spersant 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, ai rcraft, and support equipment and personnel

 Confirm dispersant availability fo r current and long range operations

 Start ordering dispersa nt 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 aer ial 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 boa t 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 ski mming 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 cont racted resources as applicable

 Industry vessels are usually best for depl oyment 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 sa fety training to be required

 Plan with the US Coast Guard for vessel inspections

In-situ Burn assets

 Determine appropriateness of in-situ burn ope ration 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 deploym ent in accordance with planning based on the actual situation, actual trajectories a nd oil budgets

 VOO identification and training in advance of spill nearing sh oreline 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 re mote 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 Re sponse Team level (Region 6)

Vessel Deployment Dedicated Near Shore skimming systems

 FRVs

 Egmopol and Marco SWS

 Operate with aerial spotter directi ng systems to observed oil slicks

VOO

 Use Petrobras America Inc.’s cont racted resources as applicable

 Industry vessels are usually best for depl oyment 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 sa fety 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 eq uipment and their availability

 Previous contingency planning contained in the appropriate Area Contingency Plan, and currently for Louisiana, The State of Loui siana 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 site s 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 respons e personnel as close to the job site as possible to maximize on-site work time

 Boom tending, repair, replacement and security (u se of local assets may be advantageous)

 Constant awareness of weather and oil moveme nt 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 se parate into distinct phases when left in a quiescent state. When separati on occurs, the relatively clean water phase can be siphoned or decanted back to the recovery point with minima l, if any, impact. Decan ting therefore increases the effective on-site oil storage capacity a nd 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 rela tion 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 a nd/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 opera tions ceased when seas reache d 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 curren ts along the Texas coast are from the southeast and northeast quadrants. Ten to 20 foot waves may occur dur ing hurricanes. The combined effect of the winds, surface currents, and waves refracting shoreward produce the prevailing westerly longshore currents.

Tides are semi-diurnal and diurna l, and range in height from le ss 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 expe cted during severe hurricanes a nd 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 wi nter 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 wint er and easterly winds in the summer. Average wind speed is generally 14-15 mph along the coast. Wave he ights 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 temperatur e will range from 50 and 60  ̊ F.

The Atlantic and Gulf of Mexico hurricane seas on is officially from 1 June to 30 November. 97% of all tropical activity occurs within this window. The Atlant ic 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 occurri ng then. Maximum activity is in early to mid September. Once in a few years there may be a hurri cane occurring "out of season" - primarily in May or December. Globally, September is the mo st 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. Th e 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 2Petrobras America Inc. Page H-14Initial Exploration Plan November, 2011Walker Ridge 376 (OCS-G 33375)WCD Scenario– BASED ON WELLBLOWOUT DURING DRILLING OPERATIONS (169 miles from shore)37,928 bbls of crude oil (Volume considering natural weathering)API Gravity 26°FIGURE 2 – Equipment Response Time to WR 376 BDispersant/SurveillanceDispersant/SurveillanceDispersantCapacity (gal)StorageCapacityPersonsReq.From Hrs to ProcureHrs toLoadoutTravel to site Total HrsCGABasler 67T 2000 NA 2 Houma 1 1 1.1 3.1ASIDC 3 1200 NA 2 Houma 1 1 1.5 3.5DC 3 1200 NA 2 Houma 1 1 1.5 3.5Aero Commander NA NA2 Houma 1 1 1.1 3.1Offshore ResponseOffshore Equipment NoStagingEDRCStorageCapacityVOOPersonsRequiredFromHrs toProcureHrs toLoadoutHrs toGOMTravel toSpill SiteHrs toDeployTotalHrsCGAHOSS Barge 43000 4000 3 Tugs 8 Harvey 7 0 5 21.9 1 34.9Recovered Oil Storage NoStagingEDRCStorageCapacityVOOPersonsRequiredFromHrs toProcureHrs toLoadoutHrs to GOMTravel toSpill SiteHrs toDeployTotalHrsEnterprise Marine Services LLC (available through contract with CGA)CTCo 2603 NA 25000 1 Tug 6 Amelia 4 12 4 28.57 1 49.57CTCo 5001 NA 47000 1 Tug 6 Amelia 4 12 4 28.57 1 49.57Petrobras America Inc. Page H-15Initial Exploration Plan November, 2011Walker Ridge 376 (OCS-G 33375)Staging Area: VeniceOffshore Equipment WithStagingEDRCStorageCapacityVOOPersonsReq.FromHrs toProcureHrs toLoadoutTravel toStagingTravel toSiteHrs toDeployTotalHrsCGAFRU (1) + 100 bbl Tank (2) 3770 200 1 Utility 6 Belle Chasse 1 2 2 14.8 1 20.8FRU (1) + 100 bbl Tank (2) 3770 200 1 Utility 6 Galveston 1 2 8 14.8 1 26.8FRU (3) + 100 bbl Tank (5) 11310 500 1 Utility 6 Houma 1 2 3 14.8 1 21.8FRU (1) + 100 bbl Tank (2) 3770 200 1 Utility 6 Ingleside 1 2 11 14.8 1 29.8FRU (1) + 100 bbl Tank (2) 3770 200 1 Utility 6 Lake Charles 1 2 5.5 14.8 1 24.3FRU (2) + 100 bbl Tank (4) 7540 400 1 Utility 6 Venice 1 2 0 14.8 1 18.842” Auto Boom (5000’) NA NA 10 Crew20 Belle Chasse 1 2 2 14.8 1 20.842” Auto Boom (5000’) NA NA 10 Crew 20 Galveston 1 2 8 14.8 1 26.842” Auto Boom (5000’) NA NA 10 Crew 20 Houma 1 2 3 14.8 1 21.842” Auto Boom (2500’) NA NA 6 Crew 12 Ingleside 1 2 11 14.8 1 29.842” Auto Boom (5000’) NA NA 10 Crew20 Lake Charles 1 2 5.5 14.8 1 24.342” Auto Boom (2500’) NA NA 6 Crew 12 Pascagoula 1 2 4 14.8 1 22.81000’ Hydro-Fire Boom(In-Situ Burn)NA NA 8 Utility 40 BelleChasse 1 4 2 14.8 6 27.8Petrobras America Inc. Page H-16Initial Exploration Plan November, 2011Walker Ridge 376 (OCS-G 33375)Nearshore ResponseNearshore Recovered OilStorage No StagingEDRCStorageCapacityVOOPersonsRequiredFromHrs toProcureHrs toLoadoutHrs to GOMTravel toSpill SiteHrs toDeployTotalHrsEnterprise Marine Services LLC (available through contract with CGA)CTCo 2604 NA 20000 1 Tug 6 Amelia 4 12 4 25 1 46CTCo 2606 NA 20000 1 Tug 6 Amelia 4 12 4 25 1 46Staging Area: VeniceNearshore and InlandSkimmers With StagingEDRCStorageCapacityVOOPersonsReq.FromHrs toProcureHrs toLoadoutTravel toStagingTravel toDeploymentHrs toDeployTotalHrsCGASWS Egmopol 3000 100 NA 3 Galveston 1 2 8 2 0 13SWS Egmopol 3000 100 NA 3 Houma 1 2 3 2 0 8SWS Marco 3588 34 NA 3 Houma 1 2 3 2 0 8SWS Marco 3588 20 NA 3 LakeCharles 1 2 5.5 2 0 10.5Rope Mop 77 2 0 3 Belle Chasse 1 2 2 2 0 7RO Storage Barge NA 249 Towed 0 Galveston 1 2 8 2 0 13RO Storage Barge NA 249 Towed 0 Houma 1 2 3 2 0 8RO Storage Barge NA 249 Towed 0 Lake Charles 1 2 5.5 2 0 10.5RO Storage Barge NA 249 Towed 0 Venice 1 2 0 2 0 5Petrobras America Inc. Page H-17Initial Exploration Plan November, 2011Walker Ridge 376 (OCS-G 33375)Shoreline ProtectionStaging Area: Venice18” Shoreline ProtectionBoomVOOPersonsReq.Storage/WarehouseLocationHrs toProcureHrs toLoadoutTravel toStagingTravel toDeploymentHrs toDeployTotal HrsOil Mop (available through Letter of Intent)10,000’ 18” Boom 4 Crew 10 New Iberia, LA 1 1 4 2 3 1110,000’ 18” Boom 4 Crew 10 Port Arthur, TX 1 1 6.25 2 3 13.2520,000’ 18” Boom 8 Crew 20 Belle Chasse, LA 1 1 1.75 2 6 11.7510,000’ 18” Boom 4 Crew 10 Port Allen, LA 1 1 3.5 2 3 10.510,000’ 18” Boom 4 Crew 10 Houma, LA 1 1 3.5 2 3 10.515,000’ 18” Boom 6 Crew 14 Gretna, LA (Warehouse) 2 2 2 2 4 12AMPOL (available through Letter of Intent)42,000’ 18” Boom 16 Crew 40 New Iberia, LA 2 2 4 2 12 2220,000’ 18” Boom 8 Crew 20 New Orleans, LA 2 2 2 2 6 14Beach Boom EDRCStorageCapacityVOOPersonsReq.FromHrs toProcureHrs toLoadoutTravel toStagingTravel toDeploymentHrs toDeployTotalHrsCGABeach Boom (2000’) NA NA NA 6 Galveston 1 2 8 1 2 14Beach Boom (1000’) NA NA NA 4 Ingleside 1 2 11 1 2 17Beach Boom (2000’) NA NA NA 6 Pascagoula 1 2 4 1 2 10Petrobras America Inc. Page H-18Initial Exploration Plan November, 2011Walker Ridge 376 (OCS-G 33375)Wildlife Response EDRCStorageCapacityVOOPersonsReq.FromHrs toProcureHrs toLoadoutTravel toStagingTravel toDeploymentHrs toDeployTotalHrsCGAWildlife Support Trailer NA NA NA 2 Houma 1 2 3 1 2 9Bird Scare Guns (24) NA NA NA 2 Belle Chasse 1 2 2 1 2 8Bird Scare Guns (12) NA NA NA 2 Galveston 1 2 8 1 2 14Bird Scare Guns (24) NA NA NA 2 Houma 1 2 3 1 2 9Bird Scare Guns (12) NA NA NA 2 Ingleside 1 2 11 1 2 17Bird Scare Guns (24) NA NA NA2 Lake Charles 1 2 5.5 1 2 11.5Bird Scare Guns (24) NA NANA 2 Pascagoula 1 2 4 1 2 10Response Asset TotalOffshore EDRC 76,930Offshore Recovered Oil Storage 77,700Nearshore / Shallow Water EDRC 13,253Nearshore / 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 wate r 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 en dangered species or marine mammals as listed in the ESA will be “taken” as a result of th e operations proposed under this plan.

To date, it has been documented that the use of explosives and/or seis mic 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 Fl ower Garden Banks National Marine Sanctuary; therefore, the requested informati on 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 follo wing stipulation attached to Lease OCS-G 33375 Walker Ridge Block 376.

Marine Protected Species Lease Stipulation No. 8 is meant to reduce the po tential 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 observa tions of injured or dead protec ted species, and the prevention of intentional and/or accidental introducti on of debris into th e 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 fort h 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 Su rvey 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 AI RCRAFT INFORMATION

(A) GENERAL The most practical, direct route from the s horebase 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 w ith the distance of th e 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 dr illing unit.Solid and Liquid WastestransportationType of Waste Composition Transport MethodName/Location ofFacilityAmount Disposal MethodOil-based drilling fluid or mud NA NA NA NA NASynthetic-based drilling fluid or mudContinuous phase of thedrilling fluid is a syntheticmaterialTanks or drums on offshore supportvesselsUS Liquids (PortFourchon, LA) orNewpark Services (PortFourchon, LA)750 bbls perwellRecycledCuttings wetted with Water-based fluid NA NA NA NA NACuttings wetted with Synthetic-based fluid NA NA NA NA NACuttings wetted with oil-based fluids NA NA NA NA NAProduced sand NA NA NA NA NATrash and debrisNon-hazardous garbage,trash, and debris that can notbe recycledContainers on offshore support vesselsWaste Management(Raceland, LA)One standardcontainer perweekLandfillUsed oilLube oils (maintenance)Drums on offshore support vessels Martin (Port Fourchon, LA0-1 bbl perweekRecycledWash water NA NA NA NA NAChemical product wastes NA NA NA NA NAWaste DisposalAttachment L-1. WASTES YOU WILL TRANSPORT AND /OR DISPOSE OF ONSHORE FROM DRILLING RIGSProjected generated waste! ! ! ! ! !

! !

! ! ! ! ! ! ! !

G r e e n C a n y o n

W a l k e r R i d g e L u n d S h i p S h o a l

A t w a t e r V a l l e y S o u t h T i m b a l i e r

M i s s i s s i p p i C a n y o n E u g e n e I s l a n d

E w i n g B a n k W e s t D e l t a

S h i p S h o a l S o u t h G r a n d I s l e

S o u t h T i m b a l i e r S o u t h W e s t D e l t a S o u t h S o u t h P e l t o F o u r c h o n C o c o d r i e G r a n d I s l e R i v e r R i d g e

T e r

r e b o n n e L a f o u r c h e P l a q u e m i n e s J

e f

f e r

s o n 

# P e t r o b r a s A m e r i c a , I n c

. V i c i n i t y M a p W a l k e r R i d g e 3 7 6

W R 3 7 6 ~ 1 6 9 M i l e s t o S h o r e

~ 1 7 7 M i l e s t o F o u r c h o n

, L A S h o r e b a s e

### 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 onshor e 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 MANAGEMEN T (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 PROD UCING 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, H 2 S 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 f eature. 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 concentr ations greater than 500 ppm might be encountered. All activities that could result in an accide ntal 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 o ccurrence 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 im pact 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 trans portation of produced fluids to shor e 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, completi on 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 th e closest designated Topographic Features Stipulation Block (Diaphus Bank a nd Ewing-1 Bank); therefore, no a dverse impacts are expected.

Accidents: It is unlikely that an acci dental 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 de pth, 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 fe atures 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 subs urface 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 activitie s, which could impact topographic features.

2. Pinnacle Trend Area Live Bottoms Potential IPFs on pinnacle trend area live bo ttoms include effluent s and accidents.

Effluents: Walker Ridge Block 376 is 228 miles from th e closest live bottom (p innacle trend) area; therefore, no adverse impacts are expected.

Accidents: It is unlikely that an acci dental 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 concentr ations 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 fr om a live bottom (pinnacl e trend) area. The activ ities 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 liv e 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 acci dental 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. O il from a surface spill can be driven into the water column; measurable amounts have been documented dow n to a 10 m depth. At this depth, the oil is found only at concentrations severa l 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 emissi ons, physical disturbances to the se afloor, 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, on ly an insignificant amount of seafloor will be disturbed. Because physical disturbances to th e seafloor will be minimized by the use of a drill ship, PAI’s proposed operations in Walker Ri dge Block 376 would not cau se impacts to benthic communities.

5. Water Quality

IPFs that could result in water quality degradation from the propos ed operations in Walker Ridge Block 376 include efflue nts 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 a nd monitoring and toxicity testi ng are regulated by the EPA NPDES permit, thereby eliminating many significant biologica l or ecological effects. Operational discharges are not expected to cause significant adverse im pacts to water quality.

Accidents: Oil spills have the potential to alter offshor e 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 percen t 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 barr el associated with drilling activit ies. 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 w ould be temporarily affected by th e 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 leve ls. Historically, changes in offshore water quality from oil spills have only been detected during the lif e of the spill and up to several months afterwards. Most of the components of oil are in soluble in water and therefore floa t. The activities proposed in this plan will be covered by PAI’s Regional Oil Spi ll Response Plan (refer to information submitted in Appendix H ).

There are no other IPFs (including em issions, physical disturbances to th e seafloor, and wastes sent to shore for disposal) from the proposed activitie s which could cause impacts to water quality.

6. Fisheries IPFs that could cause impacts to fi sheries 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 hundr ed meters down-current from the discharge point. Offshore discharges are expected to disperse and dilute to very ne ar 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 su ch an event would occur from the proposed activities (refer to Item 5

, Water Quality). The effects of oil on mobile adult finfish or shellfis h 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 me tabolites 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 disturbanc es to the seafloor or wastes sent to shore for disposal from the proposed activities wh ich 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 ea ters, including dwarf and pygmy killer whale, Risso’s dolphin, rough-toothed dolphi n, and Cuvier’s beaked whale, occurred most frequently along the upper slope in areas outside of anticyclones. I PFs that could cause impacts to marine mammals as a result of the proposed operati ons in Walker Ridge Block 376 include emissions, effluents, discarded trash a nd 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 parasite s, disease, environmental contaminants, and/or predation (Majors and Myrick, 1990) . There is little conclusive evid ence for long-term displacements and population trends for marine mammals relative to noise.

Effluents: Drilling fluids and cuttings discharges c ontain 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 ac tivities is not expected to subs tantially harm marine mammals. Operators are prohibited from de liberately 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 accordan ce with the regulations and also avoid accidental loss of solid waste items by maintaining waste management plans, manifesting tr ash sent to shore, and using special precautions such as covering outside trash bins to prevent acci dental loss of solid waste. Special caution will be exercised when handling and disposing of small ite ms and packaging materials, particularly those made of non-biodegradable, environmentally persis tent materials such as plastic or glass.

Informational placards will be post ed on all vessels and f acilities having sleeping or food preparation capabilities. All offshore personne l, including contractor s and other support se rvices-related personnel (e.g. helicopter pilots, vessel captai ns and boat crews) will be indoctrinated on waste procedures, and will view the video (or Mi crosoft 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 pe rsonnel will also receive an expl anation from PAI management or

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- 7 Initial Exploration Plan November, 2011 Walker Ridge 376 (OCS-G 33375) the designated lease operator management that empha sizes 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 main taining a vigilant watch for marine mammals and maintaining a safe distance when they are sighted. Vessel crews shoul d use a reference guide to help identify the twenty-eight species of whales and dolphins, and the singl e species of manatee that may be encountered in the Gulf of Mexico OCS. Vessel crews must report si ghtings 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 Tu rtle 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 cause d by a collision with a cont ract 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 an d 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 activit ies may increase vessel traffic in the area, which could add to changes in cetac ean behavior and/or distribution, thereby causing a dditional stress to the animals. The effect of oil dispersants on cetaceans is not known. Th e 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 pr oducts. The activities proposed in this plan will be covered by PAI’s OSRP (refer to inform ation 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 opera tions include emissions, effluents, discarded trash and debris, and accidents. GulfCet II studies sighted most loggerhead, Kemp’s ridley and leatherback sea turtles over shel f waters. Historically these species have been sighted up to the shelf’s e dge. They appear to be more abundant east of the Mississippi River than they are west of the river (Fritts et al., 1983b; Lo hoefener et al., 1990). Deep wa ters may be used by all species as a transitory habitat.

Emissions: Noise from drilling activities , support vessels, and helicopter s may elicit a startle reaction from sea turtles, but this is a temporary disturbance.

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- 8 Initial Exploration Plan November, 2011 Walker Ridge 376 (OCS-G 33375) 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 turt les (Balazs, 1985). The limited amount of marine debris, if any, resulting from the proposed activities is not expected to substantia lly harm sea turtles. Oper ators are prohibited from deliberately discharging debris as mandated by MARPOL-Annex V and the Marine Plastic Pollution Research and Control Act, and regulations impose d by various agencies including the United States Coast Guard (USCG) and the Environmental Prot ection Agency (EPA). PAI will operate in accordance with the regulations and also avoid acci dental 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 lo ss of solid waste. Special caution will be exercised when handling and disposing of small items and pack aging materials, particularly those made of nonbiodegradable, environmentally persistent materials such as plastic or glass.

Informational placards will be post ed on all vessels and f acilities having sleeping or food preparation capabilities. All offshore personne l, including contractor s and other support se rvices-related personnel (e.g. helicopter pilots, vessel captai ns and boat crews) will be indoctrinated on waste procedures, and will view the video (or Mi crosoft 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 pe rsonnel will also receive an expl anation from PAI management or the designated lease operator management that empha sizes their commitment to waste management in accordance with NTL No. 2007-G03.

Accidents: Collisions between support vessels and s ea 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 crew s should use a reference guide to help identify the five species of sea turtles that may be encountere d in the Gulf of Mexico OCS. Vessel crews must report sightings of any injured or dead protected s ea 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 th e injury or death was caused by a collision with a contract vessel, the BOEM must be notified within 24 hour s of the strike by email to protectedspecies@boemre.gov . If the vessel is the res ponsible party, it is requi red to remain available to assist the respective salvage a nd 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 th eir food. Exposure to oil can be fatal, pa rticularly 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 respons e activities may increase vessel tr affic in the area, which could

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- 9 Initial Exploration Plan November, 2011 Walker Ridge 376 (OCS-G 33375) 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 coas tline. Therefore, no special mitigation, monitoring, or reporting requirem ents 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 im pact onshore air quality because of the prevailing atmospheric conditions, emission height, emission rate s, and the distance of Walker Ridge Block 376 from the coastline. There are no ot her IPFs (including effl uents, physical disturbances to the seafloor, wastes sent to shore for treatmen t 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 in clude disturbances to the seafloor.

Physical disturbances to the seafloor: A drill ship is being us ed 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 dril l 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 th e seafloor with sector scanning sonar within a minimum 500’ radius of the proposed well location( s) prior to or upon comme ncement 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. Copi es 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 ever y reasonable effort to preserve and protect that cultural resource.

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- 10 Initial Exploration Plan November, 2011 Walker Ridge 376 (OCS-G 33375) 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 prehistori c archaeological sites as a result of the proposed operations in Walker Ridge Block 376 in clude disturbances to the seafloor.

Physical disturbances to the seafloor: A drill ship is being us ed 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’ pr oposed operations in Walker Ridge Block 376 would not cause impacts to prehistoric archaeo logical sites.

PAI will perform an ROV survey imaging 100% of th e seafloor with sector scanning sonar within a minimum 500’ radius of the proposed well location( s) prior to or upon comme ncement 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 cer tifications and a circle radius plat of the survey area will be submitted to the BOEM. Should a res ource 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 pr ehistoric 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 es tuarine 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 Tren d Stipulation would prevent most of the potential impacts on livebottom communities and EFH from operational waste di scharges. 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, there by eliminating many significant

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- 11 Initial Exploration Plan November, 2011 Walker Ridge 376 (OCS-G 33375) biological or ecological effects. Operational discha rges 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 a nd estuaries, as well as OCS waters when pelagic eggs and larvae are present, have the greatest potential to affect fisher ies. 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 ac tivities which could impact essential fish habitat.

2. Marine and Pelagic Birds IPFs that could impact marine birds as a resu lt of the proposed activities include air emissions, accidental oil spills, and discarded trash a nd debris from vessel s 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 lo calized, low-level petroleum hydrocarbon contamination. However, it is unlikely that an oil spill w ould occur from the propo sed activities (refer to Item 5

, Water Quality). Marine and pelagic birds feedi ng at the spill location ma y experience chronic, nonfatal, physiological stress. It is expected that few, if any, coas tal 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 deliberatel y discharging debris as mandated by MARPOL-Annex V and the Marine Plastic Pollution Research and Control Act, and regulat ions imposed by various agencies including the United States Coast Guard (USCG) and the Environm ental Protection Agency (EPA). PAI will operate in accordance with the re gulations and also avoid accidental loss of solid waste items by maintaining waste mana gement 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 ha ndling and disposing of small it ems and packaging materials, particularly those made of non-biod egradable, environmentally persiste nt 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 c ontractors and other support servicesrelated personnel (e.g. helicopter pilots, vessel captain s 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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- 12 Initial Exploration Plan November, 2011 Walker Ridge 376 (OCS-G 33375) marine trash and debris training video annually. Offshore personnel wi ll also receive an explanation from PAI management or the designated leas e operator management that emphasizes their commitment to waste management in accordance w ith 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 e ffluents, physical disturbances to the seafloor, or wastes sent to shore for treatment or disposal) from the proposed activities which could imp act marine and pelagic birds.

3. Public Health and Safety Due to Accidents.
There are no IPFs (emissions, effluent s, physical disturbances to the se afloor, wastes sent to shore for treatment or disposal or accide nts, including an accidental H 2 

### S 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 H 2 

### S absent.

Coastal and Onshore

1. Beaches IPFs from the proposed activities th at 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 th e distance from shore (168 miles) and the response capabilities that would be implemented, no significan t 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 ar e prohibited from deliberately di scharging 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 regulat ions and also avoid accidental loss of solid waste items by maintaining waste management pl ans, 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 a nd disposing of small items and packaging materials, particularly those made of non-biodegradable, envi ronmentally persistent materials such as plastic or glass.

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- 13 Initial Exploration Plan November, 2011 Walker Ridge 376 (OCS-G 33375) Informational placards will be post ed on all vessels and f acilities having sleeping or food preparation capabilities. All offshore personne l, including contractor s and other support se rvices-related personnel (e.g. helicopter pilots, vessel captai ns and boat crews) will be indoctrinated on waste procedures, and will view the video (or Mi crosoft 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 pe rsonnel will also receive an expl anation from PAI management or the designated lease operator management that empha sizes their commitment to waste management in accordance with NTL No. 2007-G03.

There are no other IPFs (emissions, e ffluents, 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 th at 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 resp onse capabilities that would be implemented, no impacts are expected. The activities pr oposed 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. Op erators are prohibited from delib erately discharging debris as mandated by MARPOL-Annex V and the Marine Plas tic Pollution Research and Control Act, and regulations imposed by various ag encies including the United States Coast Guard (USCG) and the Environmental Protection Agency (EPA). PAI will ope rate in accordance with the regulations and also avoid accidental loss of solid waste items by mainta ining waste management plans, manifesting trash sent to shore, and using special precautions such as covering outside trash bi ns to prevent accidental loss of solid waste. Special caution will be exercise d when handling and disposing of small items and packaging materials, particularly those made of non-biodegradable, envi ronmentally persistent materials such as plastic or glass.

Informational placards will be post ed on all vessels and f acilities having sleeping or food preparation capabilities. All offshore personne l, including contractor s and other support se rvices-related personnel (e.g. helicopter pilots, vessel captai ns and boat crews) will be indoctrinated on waste procedures, and will view the video (or Mi crosoft 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 pe rsonnel will also receive an expl anation from PAI management or the designated lease operator management that empha sizes their commitment to waste management in accordance with NTL No. 2007-G03.

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- 14 Initial Exploration Plan November, 2011 Walker Ridge 376 (OCS-G 33375) There are no other IPFs (emissions, e ffluents, physical disturbances to the seafloor, or wastes sent to shore for treatment or disposal) from the pr oposed 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 ac tivities (refer to Item 5 , Water Quality). Given the distance from shore (168 miles) and th e response capabilities that would be implemented, no impacts are expected. The activities proposed in this plan will be covere d by PAI’s’ Regional OSRP (refer to information submitted in Appendix H ).

Discarded trash and debris: Coastal and marine birds are highl y susceptible to entanglement in floating, submerged, and beached marine debris: speci fically plastics. Operat ors are prohibited from deliberately discharging debris as mandated by MARPOL-Annex V and the Marine Plastic Pollution Research and Control Act, and regulations impose d by various agencies including the United States Coast Guard (USCG) and the Environmental Prot ection Agency (EPA). PAI will operate in accordance with the regulations and also avoid acci dental 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 pack aging 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 c ontractors and other support servicesrelated personnel (e.g. helicopter pilots, vessel captain s 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 wi ll also receive an explanation from PAI management or the designated leas e operator management that emphasizes their commitment to waste management in accordance with NTL No. 2007-G03.

There are no other IPFs (emissions, e ffluents, 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 act ivities could cause impacts to coastal wildlife refuges. However, it is unlikely th at an oil spill would occur from th e proposed activities (refer to Item 5, Water Quality). Due to the distance from shor e (168 miles) and the res ponse capabilities that would be implemented, no impacts are expected. The activ ities proposed in this plan will be covered by PAI’s’ Regional OSRP (refer to information submitted in Appendix H ).

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- 15 Initial Exploration Plan November, 2011 Walker Ridge 376 (OCS-G 33375) Discarded trash and debris: Operators are prohibited from de liberately discharging debris as mandated by MARPOL-Annex V, the Marine Plas tic Pollution Research and Control Act and regulations imposed by various ag encies including the United States Coast Guard (USCG) and the Environmental Protection Agency (EPA ). PAI will operate in accordan ce with the regulations and also avoid accidental loss of solid waste items by mainta ining waste management plans, manifesting trash sent to shore, and using special precautions such as covering outside trash bi ns to prevent accidental loss of solid waste. Special caution will be exerci sed when handling and disposing of small items and packaging materials, particularly those made of non-biodegradable, envi ronmentally 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 c ontractors and other support servicesrelated personnel (e.g. helicopter pilots, vessel captain s 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 wi ll also receive an explanation from PAI management or the designated leas e operator management that emphasizes their commitment to waste management in accordance with NTL No. 2007-G03.

There are no other IPFs (emissions, e ffluents, 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 activiti es (refer to Item 5

, Water Quality). Due to the distance from the neares t 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 covere d by PAI’s’ Regional OSRP (refer to information submitted in Appendix H).

Discarded trash and debris: Operators are prohibited from de liberately discharging debris as mandated by MARPOL-Annex V, the Marine Plas tic Pollution Research and Control Act and regulations imposed by various ag encies 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 mainta ining waste management plans, manifesting trash sent to shore, and using special precautions such as covering outside trash bi ns to prevent accidental loss of solid waste. Special caution will be exerci sed when handling and disposing of small items and packaging materials, particularly those made of non-biodegradable, envi ronmentally 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 c ontractors and other support services-

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- 16 Initial Exploration Plan November, 2011 Walker Ridge 376 (OCS-G 33375) related personnel (e.g. helicopter pilots, vessel captain s 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 wi ll also receive an explanation from PAI management or the designated leas e operator management that emphasizes their commitment to waste management in accordance with NTL No. 2007-G03.

There are no other IPFs (emissions, e ffluents, physical disturbances to the seafloor, or wastes sent to shore for treatment or disposal) fro m 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 th e proposed activities. No impacts are expected on the proposed activit ies from site-specific environmental conditions.

(D) ENVIRONMENTAL HAZARDS During the hurricane season, June through November, the Gulf of Mexico is imp acted by an average of ten tropical storms (39-73 mph wind s), of which six become hurricanes ( > 74 mph winds). Due to its location in the gulf, Walker Ridge Block 376 may e xperience hurricane and tropical storm force winds, and related sea currents. These factors can adversel y 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 equi pment 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 acco rdance with NTL No.’s 2008-G09, 2009-G10, and 2010- N10.

2. Structure Installation Operator will not conduct structure instal lation operations duri ng Tropical Storm or Hurricane threat.

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- 17 Initial Exploration Plan November, 2011 Walker Ridge 376 (OCS-G 33375) (E) ALTERNATIVES No alternatives to the proposed activities were cons idered 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 co nsulted regarding potential impact s associated w ith 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 ope rations on cold water marine mammals: a literature re view. 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, Ar gonne National Laboratory, ANL/EAD/TM-43.

Daly, J.M. 1997. Controlling the discharge of syntheti c-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 seabir d populations in Alaska to oil pollution. U.S. Dept. of the Interior, Bureau of Land Management, Alaska OCS Region, Anc horage. BLM-YK-ES-81- 006-1792.

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- 18 Initial Exploration Plan November, 2011 Walker Ridge 376 (OCS-G 33375) Laist, D.W. 1997. Impacts of marine debris: entanglem ent of marine life in marine debris including a comprehensive list of species with entanglement a nd ingestion records. In : Coe, J.M. and D.B. Rogers, eds. Marine debris: sources, impacts, and solutions. New Yor k, NY: Springer-Verlag. Pp. 99-139.

Majors, A.P. and A.C. Myrick, Jr. 1990. Effects of noi se 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. A nnual report to Congress – 1998.

Piatt, J.F., C.J. Lensink, W. Butler, M. Ke ndziorek, and D.R. Nysewande r. 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 co ast. The Canadian FieldNaturalist. 89:278-298.

Although not cited, the following were utilized in prepar ing this EIA: Hazard Surveys

BOEM EIS’s: GOM Deepwater Operations and Activities. Environmental Assessment. BOEM 2000-001 GOM Central and Western Planning Areas Sa les 166 and 168 Final Environmental Impact Statement. BOEM 96-0058

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- 1 Initial Exploration Plan November, 2011 Walker Ridge 376 (OCS-G 33375) APPENDIX P ADMINISTRATIVE INFORMATION

(A) EXEMPTED INFORMATION DESCRIPTION The proposed bottom-hole locations of the planne d 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.