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-09613

Type - Initial Exploration Plan

Lease(s) - OCS-G33967 Block - 365 Walker Ridge Area

Operator - Repsol E&P USA Inc.

Drill & complete Wells A,B, & C

DP SEMISUBMERSIBLE

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

should be addressed in an Environmental Assessment.

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

James Webb

Plan Coordinator

Description -

Rig Type -

Subject:

From:

March 12, 2012
PUBLIC INFORMATION 

December, 2011 

INITIAL EXPLORATION PLAN 

Lease Number(s): OCS-G 33967 

Area/Block: Walker Ridge Block 365 

Prospect Name: Mollerussa 

Offshore: Louisiana 

Submitted by: Repsol E&P USA Inc. 

 2001 Timberloch Place 

 Suite 3000 

 The Woodlands, Texas 77380 

 Wanda Slocum 

 (281) 297-1021 

 wslocum@repsol.com 

Estimated Start-up Date: August 1, 2012 

Authorized Representative: No. Copies Being Submitted: 

Suzy Younger or Judy Davidson Proprietary: 1 Copy & CD 

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

16225 Park Ten Place, Suite 700 

Houston, Texas 77084 For BOEM: 

(281) 578-3388 Plan No. 

Suzy.Younger@jccteam.com 

Judy.Davidson@jccteam.com 

 
Record of Changes 

Date Section Page Comment 

01-03-12 B Page B-3 Added statement concerning using a platform to drill 

a relief well. 

01-03-12 H Page H-1 Added WCD calculation approval statement. 

01-16-12 N Attachment N-2 Texas CZM Certification 

01-23-12 C Attachment C-5 Revised Stratigraphic Column 

01-23-12 N Attachment N-2 Included Texas CZM evaluation. 
REPSOL E&P USA INC. 

INITIAL EXPLORATION PLAN 

LEASE OCS-G 33967 

 WALKER RIDGE BLOCK 365 

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 Table 

E-1 Bathymetry and Seafloor Features Map 

F-1 Projected Generated Wastes 

L-1 Solid and Liquid Waste Transportation 

L-2 Vicinity Map 

N-1 Coastal Zone Management Consistency Certification
Repsol E&P USA Inc. Page A-1 

Initial Exploration Plan December, 2011 

Walker Ridge Block 365 (OCS-G 33967)

APPENDIX A 

PLAN CONTENTS 

(A) PLAN INFORMATION FORM 

Under this Initial Exploration Plan, Repsol E&P USA Inc. (Repsol) proposes to drill and 

complete three wells, Locations A, B & C. The wells will be drilled with a dynamically 

positioned semi-submersible MODU. Sub-sea wellheads will be installed with the rig on 

location. Water depth in the block ranges from 6,546’ to 6,574’. 

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

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

locations of the proposed well. Also included as Attachment A-3 is a Bathymetry Map showing 

the water depths across the lease block. 

(C) SAFETY AND POLLUTION PREVENTION FEATURES

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

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

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

Repsol will drill these wells with a dynamically positioned semi-submersible rig which is 

equipped with a Subsea BOP. Once a rig is contracted, BOP information and schematics will be 

included as a part of the Application for Permit to Drill. 

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

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

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

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 

(bbls) 

Number 

of Tanks 

Total 

Capacity 

(bbls) 

Fluid 

Gravity 

(API) 

Fuel Oil (Marine 

Diesel) DP Semi-Submersible 9,763 7 68,338 

No. 2 Diesel 

(36-40 API() 

 
Repsol E&P USA Inc. Page A-2 

Initial Exploration Plan December, 2011 

Walker Ridge Block 365 (OCS-G 33967)

(E) ADDITIONAL MEASURES 

Repsol has visual observation of the sea, monitoring of fluid volumes and pressures to determine 

any leaks. Also, an ROV will monitor the wellhead area subsea, the surface gas detectors, current 

meters and visual observation of the sea surface from the rig and from support vessels. 

(F) COST RECOVERY FEE 

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

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

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

OCS PLAN INFORMATION FORM 

 BOEM 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)

ATTACHMENT A-1

GENERAL INFORMATION 

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

Company Name: Repsol E&P USA Inc. BOEM Operator Number: 2805 

Address: 2001 Timberloch Place 

 Suite 3000 Contact Person: Suzy Younger or Judy Davidson 

 The Woodlands, Texas 77380 Phone Number: (281) 578-3388 

Email Address: Suzy.Younger@jccteam.com or 

Judy.Davidson@jccteam.com 

Lease(s): G33967 Area: Walker Ridge Block(s): 365 Project Name (If Applicable): Mollerussa 

Objective(s): Oil Gas Sulphur Salt Onshore Base: Fourchon, LA Distance to Closest Land (Miles): 170.4 

Description of Proposed Activities (Mark all that apply) 

 Exploration drilling Development drilling 

 Well completion Installation of production platform 

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

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

 Installation of subsea wellheads and/or manifolds Commence production 

 Installation of lease term pipelines Other (Specify and describe) 

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

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

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

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

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

Tentative Schedule of Proposed Activities 

Proposed Activity Start 

Date 

End 

Date No. of Days 

Drill and Complete Well A 8/01/12 3/07/12 218 

Drill and Complete Well B 3/08/13 9/19/13 195 

Drill and Complete Well C 1/01/14 6/30/14 180 

 

 

 

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) 

 
OCS PLAN INFORMATION FORM (CONTINUED) 

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

 BOEM 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): A Subsea Completion 

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

Surface Location Bottom-Hole Location (For Wells) 

Lease No. OCS G33967 

Area Name Walker Ridge 

Block No. 365 

Blockline 

Departures 

(in feet) 

N/S Departure: 4456’ FNL 

E/W Departure: 1913’ FEL 

Lambert X-Y 

coordinates 

X: 2,199,847 

Y: 9,657,944 

Latitude/ 

Longitude 

Latitude: 26° 36’ 20.75” 

Longitude: 91° 17’ 14.94” 

 TVD (Feet): MD (Feet): Water Depth (Feet): 6,574’ 

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

Anchor Name 

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

Chain on Seafloor

 X = Y = 

 X = Y = 

 X = Y = 

 X = Y = 

 X = Y = 

 X = Y = 

 X = Y = 

 X = Y = 

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

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

submitted for BOEM approval. We use the information to facilitate our review and data entry for OCS plans. We will protect proprietary 

data according to the Freedom of Information Act and 30 CFR 550.197. An agency may not conduct or sponsor, and a person is not 

required to respond to, a collection of information unless it displays a currently valid Office of Management and Budget Control 

Number. The use of this form is voluntary. The public reporting burden for this form is included in the burden for preparing Exploration 

Plans and Development Operations Coordination Documents. We estimate that burden to average 600 hours per response, or 640 with

an accompanying EP (1,000 hours in AKOCSR), or 690 (1,700 in AKOCSR) with an accompanying DPP or DOCD including the time 

for reviewing instructions, gathering and maintaining data, and completing and reviewing the forms associated with subpart B. Direct 

comments regarding the burden estimate or any other aspect of this form to the Information Collection Clearance Officer, Bureau of 

Ocean Energy Management, 381 Elden Street, Herndon, VA 20170. 
OCS PLAN INFORMATION FORM (CONTINUED) 

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

 BOEM 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): B Subsea Completion 

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

Surface Location Bottom-Hole Location (For Wells) 

Lease No. OCS G33967 

Area Name Walker Ridge 

Block No. 365 

Blockline 

Departures 

(in feet) 

N/S Departure: 2056’ FNL 

E/W Departure: 3269’ FEL 

Lambert X-Y 

coordinates 

X: 2,198,841 

Y: 9,660,344 

Latitude/ 

Longitude 

Latitude: 26° 36’ 44.69” 

Longitude: 91° 17’ 29.52” 

 TVD (Feet): MD (Feet): Water Depth (Feet): 6,546’ 

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

Anchor Name 

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

Chain on Seafloor

 X = Y = 

 X = Y = 

 X = Y = 

 X = Y = 

 X = Y = 

 X = Y = 

 X = Y = 

 X = Y = 

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

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

submitted for BOEM approval. We use the information to facilitate our review and data entry for OCS plans. We will protect proprietary 

data according to the Freedom of Information Act and 30 CFR 550.197. An agency may not conduct or sponsor, and a person is not 

required to respond to, a collection of information unless it displays a currently valid Office of Management and Budget Control 

Number. The use of this form is voluntary. The public reporting burden for this form is included in the burden for preparing Exploration 

Plans and Development Operations Coordination Documents. We estimate that burden to average 600 hours per response, or 640 with

an accompanying EP (1,000 hours in AKOCSR), or 690 (1,700 in AKOCSR) with an accompanying DPP or DOCD including the time 

for reviewing instructions, gathering and maintaining data, and completing and reviewing the forms associated with subpart B. Direct 

comments regarding the burden estimate or any other aspect of this form to the Information Collection Clearance Officer, Bureau of 

Ocean Energy Management, 381 Elden Street, Herndon, VA 20170. 
OCS PLAN INFORMATION FORM (CONTINUED) 

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

 BOEM 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): C Subsea Completion 

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

Surface Location Bottom-Hole Location (For Wells) 

Lease No. OCS G33967 

Area Name Walker Ridge 

Block No. 365 

Blockline 

Departures 

(in feet) 

N/S Departure: 5607’ FNL 

E/W Departure: 1401’ FEL 

Lambert X-Y 

coordinates 

X: 2,200,359 

Y: 9,656,793 

Latitude/ 

Longitude 

Latitude: 26° 36’ 09.28” 

Longitude: 91° 17’ 09.46” 

 TVD (Feet): MD (Feet): Water Depth (Feet): 6,553’ 

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

Anchor Name 

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

Chain on Seafloor

 X = Y = 

 X = Y = 

 X = Y = 

 X = Y = 

 X = Y = 

 X = Y = 

 X = Y = 

 X = Y = 

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

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

submitted for BOEM approval. We use the information to facilitate our review and data entry for OCS plans. We will protect proprietary 

data according to the Freedom of Information Act and 30 CFR 550.197. An agency may not conduct or sponsor, and a person is not 

required to respond to, a collection of information unless it displays a currently valid Office of Management and Budget Control 

Number. The use of this form is voluntary. The public reporting burden for this form is included in the burden for preparing Exploration 

Plans and Development Operations Coordination Documents. We estimate that burden to average 600 hours per response, or 640 with

an accompanying EP (1,000 hours in AKOCSR), or 690 (1,700 in AKOCSR) with an accompanying DPP or DOCD including the time 

for reviewing instructions, gathering and maintaining data, and completing and reviewing the forms associated with subpart B. Direct 

comments regarding the burden estimate or any other aspect of this form to the Information Collection Clearance Officer, Bureau of 

Ocean Energy Management, 381 Elden Street, Herndon, VA 20170. 
Location Call N/S Call E/W X Coordinate Y Coordinate Latitude Longitude WD

WR 365 A Surface 4,456' FNL 1,913' FEL 2,199,847 9,657,944 26° 36' 20.75"N 91° 17' 14.94" W ‐6,574

WR 365 B Surface 2,056' FNL 3,269' FEL 2,198,491 9,660,344 26° 36' 44.69"N 91° 17' 29.52"W ‐6,546

WR 365 C Surface 5,607' FNL 1,401' FEL 2,200,359 9,656,793 26° 36' 09.28"N 91° 17' 09.46"W ‐6,553
3® 3

3

3

3® 3

3

3

3® 3

3

3

Proposed WR365-C Well Location

Proposed WR365-B Well Location

Proposed WR365-A Well Location

-6600

-6650

-6700

-6750

-6800

-6850

-6550

-6900

-69

-7000

50

-7050

-7100

-7150

-7200

-7250

-7300

-7350

-6500

-6450

-7400

-6400

-7450

-7500

-7550

-6350

-7600

91°17'30"W91°17'0"W

26°36'30"N

26°36'0"N

2,198,0002,200,0002,202,000

9,656,000

9,658,000

9,660,000

Seabed Depth (Feet)

0 1,000 500 Feet

0 250 500 125 Meters

Chart Scale 1" = 1,000'

Seabed Depth Extract

Proposed WR365-A Well Location

(2,199,847ft E / 9,657,944ft N) 3® 3

3

3

Depth in feet below sea surface to seabed,

contoured at 50ft intervals

Figure 1

(WR365-A)

±

-6600

2000ft Radius

Block boundaries

Proposed WR365-B Well Location

(2,198,491ft E / 9,660,344ft N) 3® 3

3

3

Proposed WR365-C Well Location

(2,200,359ft E / 9,656,793ft N) 3® 3

3

3

Repsol E&P USA Inc. Page B-1 

Initial Exploration Plan December, 2011 

Walker Ridge Block 365 (OCS-G 33967)

APPENDIX B 

GENERAL INFORMATION 

(A) APPLICATIONS AND PERMITS 

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

commence under this EP: 

Application/Permit Issuing Agency Status 

Applications for Permit to 

Drill BOEM To be submitted 

(B) DRILLING FLUIDS 

Type of Drilling Fluid Estimated Volume of Drilling Fluid to be 

Used per Well 

Water-based 50,000 bbls 

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

Synthetic-based 10,000 bbls 

(C) NEW OR UNUSUAL TECHNOLOGY 

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

exploration activities. 

(D) BONDING STATEMENT 

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

$1,000,000 areawide development bond, furnished and maintained according to 30 CFR 556, 

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

(E) OIL SPILL FINANCIAL RESPONSIBILITY (OSFR) 

Repsol E&P USA Inc., BOEM company number 2805 has demonstrated or will demonstrate oil 

spill financial responsibility for the facilities proposed in this EP according to 30 CFR Part 553; 

and NTL No. 2008-N05, "Guidelines for Oil Spill Financial Responsibility for Covered 

Facilities". 

(F) DEEPWATER WELL CONTROL STATEMENT 

Repsol E&P USA Inc., BOEM company number 2805 has or will have the financial capability to 

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

(G) BLOWOUT SCENARIO 

Estimated Flow Rate 

The calculated WCD volume for the Walker Ridge Block 365 Well A is 51,929 STB oil/day for 

Wilcox open hole sections. 
Repsol E&P USA Inc. Page B-2 

Initial Exploration Plan December, 2011 

Walker Ridge Block 365 (OCS-G 33967)

Maximum Duration of Potential Blowout and Total Volume 

 For the purpose of WCD response and containment, we assume that the rate will be constant for 

the period that will be required to drill a relief well (up to 180 days). The expected discharge 

volumes over time resulting from these assumptions are shown in Table 1 below. 

Table 1. Expected discharge volumes 

Discussion of Potential for well to Bridge Over 

During the unlikely scenario of the well blowout, the well may potentially bridge over due to the 

open hole and the huge drawdown experienced by the well. The bridge over will certainly reduce 

well discharge rate and may even kill the well and stop hydrocarbon flow completely. However, 

we assume that the well is not bridged over for our worst case discharge calculation following 

the guideline from NTL-06. 

Relief Well 

At the expected time of drilling Walker Ridge Block 365 Well A in the third quarter of 2012, 

there are plans for several rigs by other operators in the Gulf of Mexico which will be capable of 

drilling a relief well designed to intersect the original wellbore at a depth near the expected 

influx and killing the well by pumping kill weight fluid. Suitable rigs (WD> 7,000’, drilling rate 

> 30,000’ hoisting 2.0 MM# or over) to perform a relief well operation include Transocean’s the 

dynamically positioned semi-submersibles Deepwater Driller, Deepwater Driller II, Deepwater 

Driller III, and the Ensco 8500, Ensco 8501, and Ensco 8502 in addition to drillships Transocean 

Clear Leader, Inspiration, and Deep Seas. Mutual aid agreements among operators for rigs with 

equipment for emergency relief well use are currently proceeding and will be in place when 

Walker Ridge Well A will be drilled. 

The expected time to temporarily abandon another well at its current location, pull riser, and 

move a relief well rig to Walker Ridge Block 365 location is about 10 days. When the rig is on 

location, the well is expected to take 180 days or less to reach a depth suitable to begin kill 

operations. 

Measures to Enhance Ability to Prevent and Reduce the Likelihood of a Blowout 

Early kick detection methods such as flow checks, connection flow signature monitoring, 

circulating out drilling breaks, and circulating out completely before the connection. In addition, 

blowout likelihood is reduced by crew training on well behavior in SBM, crew awareness to 

“stop work” if parameters become out of the ordinary, and close supervision. 

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

Blowout 

Daily rate 51,929 STB oil/day 

Fifty day cumulative 1.94 MMSTB oil 

One Hundred day cumulative 3.77 MMSTB oil 

One Hundred eighty day cumulative 6.57 MMSTB oil 
Repsol E&P USA Inc. Page B-3 

Initial Exploration Plan December, 2011 

Walker Ridge Block 365 (OCS-G 33967)

Repsol has evaluated blowout scenarios, procedures, equipment and personnel response, and 

following relief well response. Repsol is an active member of the Helix Well Containment Group 

which provides early intervention equipment and technical expertise. 

The possibility of using a nearby platform to drill a relief well was not considered. 

Included as Attachment B-1 is are worst-cast discharge calculations and analyses. (Proprietary) 
Repsol E&P USA Inc. Page C-1 

Initial Exploration Plan December, 2011 

Walker Ridge Block 365 (OCS-G 33967)

APPENDIX C 

GEOLOGICAL AND GEOPHYSICAL INFORMATION 

(A) GEOLOGICAL DESCRIPTION 

The Mollerussa prospect is a subsalt 3-way combined closure against salt and fault, comprising 

Lower Eocene and Paleocene ages reservoirs of the Wilcox Formation. The prospect covers part 

of five (3x3 mile) OCS blocks in the Walker Ridge protraction area, Walker Ridge Blocks 321, 

322, 365, 366 and 409. The structure is intended to be tested by a deviate well from a surface 

location in Walker Ridge Block 365. The Jack Field (Walker Ridge Block 759) is considered to 

be the closest field analog. 

 (B) STRUCTURE CONTOUR MAP(S) 

Current structure contour maps drawn on the top of each prospective hydrocarbon sand, showing 

the entire lease block, the location of each proposed well, and the locations of geological crosssections are included as Attachment C-1.

 (C) INTERPRETED 2-D And/Or 3-D SEISMIC LINE(S) 

Interpreted or 3-D seismic lines are included as Attachment C-2. These lines are migrated, 

annotated with depth scale, and are within 500’ of the surface locations of the proposed wells.

(D) GEOLOGICAL STRUCTURE CROSS-SECTIONS

Interpreted geological structure cross-sections showing the location and depth of each proposed 

well and at least one key horizon and the objective sands labeled using standard biostratigrahic 

terms are included as Attachment C-3. 

(E) SHALLOW HAZARDS REPORT 

A shallow hazards survey was conducted by Gardline Surveys, Inc. in May, 2011 over Walker 

Ridge Blocks 321, 322, 365, 366, 409 and 410. One hard copy and one CD of the report are 

being submitted to the BOEM under separate cover. 

(F) SHALLOW HAZARDS ASSESSMENT 

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

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

(G) HIGH-RESOLUTION SEISMIC LINES 

Attached to one Proprietary Copy of this Plan, Attachment C-2, is 3-D survey information 

including swath bathymetry/seafloor rendering/edge detection (fault scarp trends) overlain with 

the seafloor amplitude. 

(H) STRATIGRAPHIC COLUMN

A generalized biostratigraphic/lithostratigraphic column depicting each well from the seafloor to 

total depth, with each objective horizon labeled, is included as Attachment C-5.
Repsol E&P USA Inc. Page C-2 

Initial Exploration Plan December, 2011 

Walker Ridge Block 365 (OCS-G 33967)

(I) TIME VS DEPTH TABLES

Tables providing seismic travel time versus depth for the proposed well locations in areas where 

there is no well control is included as Attachment C-6.
REPSOL E & P USA INC

3D GEOHAZARD ASSESSMENT

WALKER RIDGE BLOCK 365

MOLLERUSSA PROSPECT

PROPOSED WR365-A, B AND C WELL LOCATIONS

WELL CLEARANCE LETTERS

DECEMBER 2010

Gardline Project Ref. 8600

Report Status Final

Issue Date May 16, 2011

Gardline Surveys Inc

1500 Bingle Road, Houston, Texas 77055, USA

Telephone 713 481 4630 Fax 713 464 8275 www.gardline.com
Repsol E & P USA Inc Gardline Report 8600

Well Clearance Letters – Walker Ridge Block 365 – Proposed WR365-A, B & C Well Locations

APPENDIX A – Public Shallow Hazards Statements
Repsol E & P USA Inc Gardline Report 8600

Well Clearance Letters – Walker Ridge Block 365 – Proposed WR365-A, B & C Well Locations

Public Shallow Hazards Statement – WR365-A

May 16, 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 365

OCS-(G 33967)

Ladies/Gentlemen:

Repsol E & P USA Inc contracted Gardline Surveys, Inc. to prepare a Well Clearance Letter for the 

proposed WR365-A well location in Block 365, Walker Ridge (OCS-G 33967). 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 -

6,882ft below sea surface (308ft below seabed).

This hazards summary letter is issued as a supplement to Gardline Report No. 8600 entitled: 3D 

Geohazard Assessment, Gulf of Mexico, Walker Ridge Blocks 321-322, 365-366, and 409-410, 

Mollerussa Prospect, dated December, 2010.

Seabed Hazards. The seabed is smooth at the proposed well.

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

An escarpment occurs 597ft to the southwest of the proposed well. The escarpment is the seabed 

expression of the boundary between the salt diapiric area and the mini-basin. 

No existing seabed infrastructure is located in the area.

Sub-Seabed Hazards. No gas hazards are interpreted. 
Repsol E & P USA Inc Gardline Report 8600

Well Clearance Letters – Walker Ridge Block 365 – Proposed WR365-A, B & C Well Locations

Proposed WR365-A Location (Surface)

Location Coordinates

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

Latitude 26° 36' 20.75” North Easting 2,199,847 US ft E

Longitude 91° 17’ 14.94” West Northing 9,657,944 US ft N

FEL of Walker Ridge 365 1,913ft US ft Inline 23380

FNL of Walker Ridge 365 4,456ft US ft Crossline 5506

Water Depth: -6,574ft Slope: 3.2° south

Nearest Shoreline 171 Miles @ 8° 49’ 44.44”

Port of Operation Fourchon 186 Miles @ 20° 19’ 58.81

Nearest Manned Platform A-Constitution in GC680 50.72 Miles @ 20° 26’ 12.03’’

Conclusions and Recommendations. No significant drilling problems or hazards are predicted.

Sincerely,

Repsol E & P USA, Inc.

David Ramos

PUBLIC INFORMATION
Repsol E & P USA Inc Gardline Report 8600

Well Clearance Letters – Walker Ridge Block 365 – Proposed WR365-A, B & C Well Locations

Public Shallow Hazards Statement – WR365-B

May 16, 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 365

OCS-(G 33967)

Ladies/Gentlemen:

Repsol E & P USA Inc contracted Gardline Surveys, Inc. to prepare a Well Clearance Letter for the 

proposed WR365-B well location in Block 365, Walker Ridge (OCS-G 33967). 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 -

6,833ft below sea surface (287ft below seabed).

This hazards summary letter is issued as a supplement to Gardline Report No. 8600 entitled: 3D 

Geohazard Assessment, Gulf of Mexico, Walker Ridge Blocks 321-322, 365-366, and 409-410, 

Mollerussa Prospect, dated December, 2010.

Seabed Hazards. The seabed is smooth at the proposed well. 

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

An escarpment occurs 1,193ft to the southwest of the proposed well. The escarpment is the seabed 

expression of the boundary between the salt diapiric area and the mini-basin. 

No existing seabed infrastructure is located in the area.

Sub-Seabed Hazards. No gas hazards are interpreted.
Repsol E & P USA Inc Gardline Report 8600

Well Clearance Letters – Walker Ridge Block 365 – Proposed WR365-A, B & C Well Locations

Proposed WR365-B Location (Surface)

Location Coordinates

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

Latitude 26° 36' 44.69” North Easting 2,198,491 US ft E

Longitude 91° 17’ 29.52” West Northing 9,660,344 US ft N

FEL of Walker Ridge 365 3,269ft US ft Inline 23565

FNL of Walker Ridge 365 2,056ft US ft Crossline 5473

Water Depth: -6,546ft Slope: 2.2° WSW

Nearest Shoreline 171 Miles @ 8° 49’ 44.44”

Port of Operation Fourchon 186 Miles @ 20° 19’ 58.81

Nearest Manned Platform A-Constitution in GC680 50.39 Miles @ 20° 53’ 33.59’’

Conclusions and Recommendations. No significant drilling problems or hazards are predicted.

Sincerely,

Repsol E & P USA, Inc.

David Ramos

PUBLIC INFORMATION
Repsol E & P USA Inc Gardline Report 8600

Well Clearance Letters – Walker Ridge Block 365 – Proposed WR365-A, B & C Well Locations

Public Shallow Hazards Statement – WR365-C

May 16, 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 365

OCS-(G 33967)

Ladies/Gentlemen:

Repsol E & P USA Inc contracted Gardline Surveys, Inc. to prepare a Well Clearance Letter for the 

proposed WR365-C well location in Block 365, Walker Ridge (OCS-G 33967). This letter addresses 

seafloor and shallow geologic conditions that may impact exploratory drilling operations within 2,000ft 

of the proposed well location. The depth limit of this geohazard assessment is to Top of Salt at -

7,139ft below sea surface (586ft below seabed).

This hazards summary letter is issued as a supplement to Gardline Report No. 8600 entitled: 3D 

Geohazard Assessment, Gulf of Mexico, Walker Ridge Blocks 321-322, 365-366, and 409-410, 

Mollerussa Prospect, dated December, 2010.

Seabed Hazards. The seabed is smooth at the proposed well. 

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

An escarpment occurs 460ft to the southeast of the proposed well. The escarpment is the seabed 

expression of the boundary between the salt diapiric area and the mini-basin. 

No existing seabed infrastructure is located in the area.

Sub-Seabed Hazards. No gas hazards are interpreted. 
Repsol E & P USA Inc Gardline Report 8600

Well Clearance Letters – Walker Ridge Block 365 – Proposed WR365-A, B & C Well Locations

Proposed WR365-C Location (Surface)

Location Coordinates

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

Latitude 26° 36' 09.28” North Easting 2,200,359 US ft E

Longitude 91° 17’ 09.46” West Northing 9,656,793 US ft N

FEL of Walker Ridge 365 1,401ft US ft Inline 23295

FNL of Walker Ridge 365 5,607ft US ft Crossline 5519

Water Depth: -6,554ft Slope: 4.7° northwest

Nearest Shoreline 171 Miles @ 8° 49’ 44.44”

Port of Operation Fourchon 186 Miles @ 20° 19’ 58.81

Nearest Manned Platform A-Constitution in GC680 50.89 Miles @ 20° 14’ 43.16’’

Conclusions and Recommendations. No significant drilling problems or hazards are predicted.

Sincerely,

Repsol E & P USA, Inc.

David Ramos

PUBLIC INFORMATION
Repsol E & P USA Inc Gardline Report 8600

Well Clearance Letters – Walker Ridge Block 365 – Proposed WR365-A, B & C Well Locations

APPENDIX B – Sensitive Sessile Benthic Community Statements
Repsol E & P USA Inc Gardline Report 8600

Well Clearance Letters – Walker Ridge Block 365 – Proposed WR365-A, B & C Well Locations

Sensitive Sessile Benthic Community Statement – WR635-A

Repsol E & P USA Inc

May 16, 2011

US Department of the Interior

Bureau of Ocean Energy Management, Regulation and Enforcement

1201 Elmwood Park Blvd.

New Orleans, LA 70213

Reference: Sensitive Sessile Benthic Community Summary

Walker Ridge, Block 365

OCS-(G 33967)

Ladies/Gentlemen:

Gardline Surveys Inc was contracted by Repsol E & P USA Inc to prepare a Site Clearance Letter for 

the proposed WR365-A well location in Walker Ridge Block 365 (OCS-G 33967). This letter 

addresses location proximity to potential sensitive sessile benthic community sites. Repsol E & P USA

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. 8600 entitled: 3D Geohazard Assessment, Gulf of Mexico, Walker Ridge Blocks 321-322, 365-

366, and 409-410, Mollerussa Prospect, dated December, 2010. A Biological, Physical and Socioeconomic Map is 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 2,000 feet of any proposed mud and cuttings discharge location.
Repsol E & P USA Inc Gardline Report 8600

Well Clearance Letters – Walker Ridge Block 365 – Proposed WR365-A, B & C Well Locations

Proposed WR365-A Location (Surface)

Location Coordinates

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

Latitude 26° 36' 20.75” North Easting 2,199,847 US ft E

Longitude 91° 17’ 14.94” West Northing 9,657,944 US ft N

FEL of Walker Ridge 365 1,913ft US ft Inline 23380

FNL of Walker Ridge 365 4,456ft US ft Crossline 5506

Water Depth: -6,574ft Slope: 3.2° south

Nearest Shoreline 171 Miles @ 8° 49’ 44.44”

Port of Operation Fourchon 186 Miles @ 20° 19’ 58.81

Nearest Manned Platform A-Constitution in GC680 50.72 Miles @ 20° 26’ 12.03’’

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

fluid expulsion site 12,010ft to the northwest.

Conclusions and Recommendations: The proposed WR365-A well location will not impact any 

sites favorable for development of sensitive sessile benthic communities.

Sincerely,

Repsol E&P USA, Inc.

David Ramos
±

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Proposed WR365-B Well Location

Proposed WR365-A Well Location

Proposed WR365-C Well Location

91°18'0"W91°17'0"W91°16'0"W

26°37'0"N

26°36'0"N

2,195,0002,200,0002,205,000

9,655,000

9,660,000

9,665,000

0 1,000 2,000 500 Feet

0 250 500 125 Meters

Chart scale 1" = 2,000'

Biological, Physical & Socio-Economic Plat

Proposed WR365-A Well Location

(2,199,847ft E / 9,657,944ft N) 3® 3

3

3

Proposed WR365-B Well Location

(2,198,491ft E / 9,660,344ft N) 3® 3

3

3

Depth in feet below sea surface to seabed,

contoured at 50ft intervals

-6500

20 00 ft Radius

20 00 ft Radius

BLOCK WR365 (OCS-G33967)

Proposed WR365-C Well Location

(2,200,359ft E / 9,656,793ft N) 3® 3

3

3

Block boundary

Seabed fault intersection, tick denotes 

downthrown block

200 0ft Rad ius
Repsol E & P USA Inc Gardline Report 8600

Well Clearance Letters – Walker Ridge Block 365 – Proposed WR365-A, B & C Well Locations

Sensitive Sessile Benthic Community Statement – WR635-B

Repsol E & P USA Inc

May 16, 2011

US Department of the Interior

Bureau of Ocean Energy Management, Regulation and Enforcement

1201 Elmwood Park Blvd.

New Orleans, LA 70213

Reference: Sensitive Sessile Benthic Community Summary

Walker Ridge, Block 365

OCS-(G 33967)

Ladies/Gentlemen:

Gardline Surveys Inc was contracted by Repsol E & P USA Inc to prepare a Site Clearance Letter for 

the proposed WR365-B well location in Walker Ridge Block 365 (OCS-G 33967). This letter 

addresses location proximity to potential sensitive sessile benthic community sites. Repsol E & P USA 

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. 8600 entitled: 3D Geohazard Assessment, Gulf of Mexico, Walker Ridge Blocks 321-322, 365-

366, and 409-410, Mollerussa Prospect, dated December, 2010. A Biological, Physical and Socioeconomic Map is 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 2,000 feet of any proposed mud and cuttings discharge location.
Repsol E & P USA Inc Gardline Report 8600

Well Clearance Letters – Walker Ridge Block 365 – Proposed WR365-A, B & C Well Locations

Proposed WR365-B Location (Surface)

Location Coordinates

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

Latitude 26° 36' 44.69” North Easting 2,198,491 US ft E

Longitude 91° 17’ 29.52” West Northing 9,660,344 US ft N

FEL of Walker Ridge 365 3,269ft US ft Inline 23565

FNL of Walker Ridge 365 2,056ft US ft Crossline 5473

Water Depth: -6,546ft Slope: 2.2° WSW

Nearest Shoreline 171 Miles @ 8° 49’ 44.44”

Port of Operation Fourchon 186 Miles @ 20° 19’ 58.81

Nearest Manned Platform A-Constitution in GC680 50.39 Miles @ 20° 53’ 33.59’’

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

fluid expulsion site 9,473ft to the northwest.

Conclusions and Recommendations: The proposed WR365-B well location will not impact any 

sites favorable for development of sensitive sessile benthic communities.

Sincerely,

Repsol E&P USA, Inc.

David Ramos
±

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Proposed WR365-B Well Location

Proposed WR365-A Well Location

Proposed WR365-C Well Location

91°18'0"W91°17'0"W91°16'0"W

26°37'0"N

26°36'0"N

2,195,0002,200,0002,205,000

9,655,000

9,660,000

9,665,000

0 1,000 2,000 500 Feet

0 250 500 125 Meters

Chart scale 1" = 2,000'

Biological, Physical & Socio-Economic Plat

Proposed WR365-A Well Location

(2,199,847ft E / 9,657,944ft N) 3® 3

3

3

Proposed WR365-B Well Location

(2,198,491ft E / 9,660,344ft N) 3® 3

3

3

Depth in feet below sea surface to seabed,

contoured at 50ft intervals

-6500

20 00 ft Radius

20 00 ft Radius

BLOCK WR365 (OCS-G33967)

Proposed WR365-C Well Location

(2,200,359ft E / 9,656,793ft N) 3® 3

3

3

Block boundary

Seabed fault intersection, tick denotes 

downthrown block

200 0ft Rad ius
Repsol E & P USA Inc Gardline Report 8600

Well Clearance Letters – Walker Ridge Block 365 – Proposed WR365-A, B & C Well Locations

Sensitive Sessile Benthic Community Statement – WR635-C

Repsol E & P USA Inc

May 16, 2011

US Department of the Interior

Bureau of Ocean Energy Management, Regulation and Enforcement

1201 Elmwood Park Blvd.

New Orleans, LA 70213

Reference: Sensitive Sessile Benthic Community Summary

Walker Ridge, Block 365

OCS-(G 33967)

Ladies/Gentlemen:

Gardline Surveys Inc was contracted by Repsol E & P USA Inc to prepare a Site Clearance Letter for 

the proposed WR365-C well location in Walker Ridge Block 365 (OCS-G 33967). This letter 

addresses location proximity to potential sensitive sessile benthic community sites. Repsol E & P USA 

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. 8600 entitled: 3D Geohazard Assessment, Gulf of Mexico, Walker Ridge Blocks 321-322, 365-

366, and 409-410, Mollerussa Prospect, dated December, 2010. A Biological, Physical and Socioeconomic Map is 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 2,000 feet of any proposed mud and cuttings discharge location.
Repsol E & P USA Inc Gardline Report 8600

Well Clearance Letters – Walker Ridge Block 365 – Proposed WR365-A, B & C Well Locations

Proposed WR365-C Location (Surface)

Location Coordinates

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

Latitude 26° 36' 09.28” North Easting 2,200,359 US ft E

Longitude 91° 17’ 09.46” West Northing 9,656,793 US ft N

FEL of Walker Ridge 365 1,401ft US ft Inline 23295

FNL of Walker Ridge 365 5,607ft US ft Crossline 5519

Water Depth: -6,554ft Slope: 4.7° northwest

Nearest Shoreline 171 Miles @ 8° 49’ 44.44”

Port of Operation Fourchon 186 Miles @ 20° 19’ 58.81

Nearest Manned Platform A-Constitution in GC680 50.89 Miles @ 20° 14’ 43.16’’

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

fluid expulsion site 13,378ft to the northwest.

Conclusions and Recommendations: The proposed WR365-C well location will not impact any 

sites favorable for development of sensitive sessile benthic communities.

Sincerely,

Repsol E&P USA, Inc.

David Ramos
±

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Proposed WR365-B Well Location

Proposed WR365-A Well Location

Proposed WR365-C Well Location

91°18'0"W91°17'0"W91°16'0"W

26°37'0"N

26°36'0"N

2,195,0002,200,0002,205,000

9,655,000

9,660,000

9,665,000

0 1,000 2,000 500 Feet

0 250 500 125 Meters

Chart scale 1" = 2,000'

Biological, Physical & Socio-Economic Plat

Proposed WR365-A Well Location

(2,199,847ft E / 9,657,944ft N) 3® 3

3

3

Proposed WR365-B Well Location

(2,198,491ft E / 9,660,344ft N) 3® 3

3

3

Depth in feet below sea surface to seabed,

contoured at 50ft intervals

-6500

20 00 ft Radius

20 00 ft Radius

BLOCK WR365 (OCS-G33967)

Proposed WR365-C Well Location

(2,200,359ft E / 9,656,793ft N) 3® 3

3

3

Block boundary

Seabed fault intersection, tick denotes 

downthrown block

200 0ft Rad ius
3® 3

3

3

3® 3

3

3

3® 3

3

3

WALKER RIDGE BLOCK 365 (OCS-G33964) WALKER RIDGE BLOCK 322 (OCS-G33965)

WALKER RIDGE BLOCK 365 (OCS-G33967) WALKER RIDGE BLOCK 366 (OCS-G33968)

WALKER RIDGE BLOCK 409 (OCS-G33377) WALKER RIDGE BLOCK 410 (NOT LEASED)

5200540056005800

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Proposed WR365-B Well Location

Proposed WR365-A Well Location

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2,190,000 2,190,0002,195,000 2,195,0002,200,000 2,200,0002,205,000 2,205,0002,210,000 2,210,0002,215,000

9,630,000

2,215,000

9,630,000

9,635,000 9,635,000

9,640,000 9,640,000

9,645,000 9,645,000

9,650,000 9,650,000

9,655,000 9,655,000

9,660,000 9,660,000

9,665,000 9,665,000

9,670,000 9,670,000

9,675,000 9,675,000 91°14'0"W 91°14'0"W 91°15'0"W 91°15'0"W 91°16'0"W 91°16'0"W 91°17'0"W 91°17'0"W 91°18'0"W 91°18'0"W 91°19'0"W 91°19'0"W 91°20'0"W

26°39'0"N

26°39'0"N

26°38'0"N

26°38'0"N

26°37'0"N

26°37'0"N

26°36'0"N

26°36'0"N

26°35'0"N

26°35'0"N

26°34'0"N

26°34'0"N

26°33'0"N

26°33'0"N

26°32'0"N

26°32'0"N

3D GEOHAZARD ASSESSMENT

OFFSHORE GULF OF MEXICO

WALKER RIDGE

BLOCKS 321 & 322, 365 & 366, 409 & 410

MOLLERUSSA PROSPECT

BIOLOGICAL, PHYSICAL AND SOCIO-ECONOMIC

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

REV DATE REMARKS AUTHOR DRAWN CHECKED

SURVEY DATE N/A REPORT REF 8600 REF NO

0 December 30, 2010 DRAFT JR CM ARH

GEODETIC INFORMATION

Datum Parameters

Datum Name

Ellipsoid

Semi-major Axis

Reciprocal Flattening

NAD27

NAD27

6378137

Projection Method

False Northing

False Easting

Latitude of Origin

Longitude of Origin

Standard Parallel

Scale Factor

Transverse Mercator

0

1640416.666667

0 North

9 East

0.9996

Map Projection Parameters

Chart Scale 1"=1,000'

0 1,250 2,500 3,750 5,000 6,250 625 Feet

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

Lund Henderson

Lloyd Ridge

Walker Ridge

East Breaks Green Canyon Atwater Valley Garden Banks

Alaminos Canyon Keathley Canyon

Florida Plain

LEGEND

Proposed WR365-A Well Location

(2,199,847ft E / 9,657,944ft N) 3® 3

3

3

Study Area

Not to scale

Proposed WR365-B Well Location

(2,198,491ft E / 9,660,344ft N)

Proposed WR365-C Well Location

(2,200,359ft E / 9,656,793ft N)

3® 3

3

3

3® 3

3

3

Inline

Crossline

Block boundaries

Depth in meters below sea surface to seabed,

contoured at 50ft intervals -6450

2,00 0ft Radius

2,00 0ft Radius

2,00 0ft Radius

±

Study area boundary

Region of seabed favorable for the development of sensitive

sessile benthic communities

Fault intersections at seabed. Tick denotes downthrown block.

8600.19

1 May 16, 2011 FINAL JR CM ARH
Repsol E&P USA Inc. Page D-1 

Initial Exploration Plan December, 2011 

Walker Ridge Block 365 (OCS-G 33967)

APPENDIX D 

HYDROGEN SULFIDE INFORMATION 

(A) CONCENTRATION 

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

(B) CLASSIFICATION 

In accordance with Title 30 CFR 250.490(c), Repsol requests that Walker Ridge Block 365 be 

classified by the BOEM as H2S absent. 

The basis for this determination is the evaluation of the following offset wells which were drilled 

to the stratigraphic equivalent of the Wilcox Sand Series as proposed in this EP: 

Lease OCS-G 18675 Walker Ridge Block 278 Well 001 

Lease OCS-G 31968 Walker Ridge Block 544 Well 001 
Repsol E&P USA Inc. Page E-1 

Initial Exploration Plan December, 2011 

Walker Ridge Block 365 (OCS-G 33967)

APPENDIX E 

BIOLOGICAL, PHYSICAL AND SOCIOECONOMIC INFORMATION 

(A) DEEPWATER BENTHIC COMMUNITIES 

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

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

of 2,000 feet around each well. 

ANALYSIS 

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

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

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

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

communities are not located within 2,000 feet of any proposed muds and cuttings discharge 

location. 

(B) TOPOGRAPHIC FEATURES MAP 

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

activity zone”. 

(C) TOPOGRAPHIC FEATURES STATEMENT (SHUNTING) 

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

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

(D) LIVE BOTTOMS (PINNACLE TREND) MAP 

Walker Ridge Block 365 is not located within 61 meters (200 feet) of any pinnacle trend feature; 

therefore a separate bathymetric map is not required. 

(E) LIVE BOTTOMS (LOW RELIEF) STIPULATION 

Walker Ridge Block 365 is not located within 100 feet of any pinnacle trend feature with vertical 

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

(F) POTENTIALLY SENSITIVE BIOLOGICAL FEATURES 

Walker Ridge Block 365 is not located within 30 meters (100 feet) of potentially sensitive 

biological features; therefore, biologically sensitive area maps are not required. 

(G) REMOTELY OPERATED VEHICLE (ROV) SURVEYS 

BOEM has determined that there is enough data gathered in this grid area, therefore, we will not 

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

biological and physical observation. 
Repsol E&P USA Inc. Page E-2 

Initial Exploration Plan December, 2011 

Walker Ridge Block 365 (OCS-G 33967)

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

MAMMAL INFORMATION 

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

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

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

In accordance with 30 CFR 250, Subpart B, and further outlined in NTL 2008-G04, 

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

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

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

activities under this plan. 

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

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

Species Scientific Name Status 

Potential Presence 

Critical Habitat Designated 

in the Gulf of Mexico Lease Area Coastal 

Sea Turtles 

Loggerhead Turtle Carettsa Caretta T x x None 

Green Turtle Chelonia mydas T,E x x None

Leatherback Turtle Dermochelys corlacea E x x None

Hawksbill Turtle Eretmochelys imbricata E x x None

Kemp’s ridley turtle Lepidochelys kempli E x x None

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

The table provided below identifies the seven species of marine mammals that are listed as 

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

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

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

Species Scientific Name Status 

Potential Presence 

Critical Habitat Designated 

in the Gulf of Mexico Lease Area Coastal 

Marine Mammals 

Sperm Whale Physeter macrocephalus E x -- None 

Florida manatee Trichechus manatus 

latirostris 

E -- x Florida (Peninsular)

Blue Whale Balaenoptera masculus E x -- None

Fin whale Balaenoptera physalus E x -- None

Humpback whale Megaptera novaeangliae E x -- None

North Atlantic right 

whale 

Eubalaena glacialis E x -- None 

Sei whale Balaenopiera borealis E x -- None 

 
Repsol E&P USA Inc. Page E-3 

Initial Exploration Plan December, 2011 

Walker Ridge Block 365 (OCS-G 33967)

(I) ARCHAEOLOGICAL REPORT 

Walker Ridge Block 365 is not located in an area determined to have any historic or prehistoric 

cultural resources. 

(J) AIR AND WATER QUALITY INFORMATION 

Air and water quality information is not required by BOEM to be included in this plan. 
3® 3

3

3

3® 3

3

3

3® 3

3

3

WALKER RIDGE BLOCK 321 (OCS-G33964) WALKER RIDGE BLOCK 322 (OCS-G33965)

WALKER RIDGE BLOCK 365 (OCS-G33967)

WALKER RIDGE BLOCK 366 (OCS-G33968)

WALKER RIDGE BLOCK 409 (OCS-G33377) WALKER RIDGE BLOCK 410 (NOT LEASED)

5200540056005800

24800

24600

24400

24200

24000

23800

23600

23400

23200

23000

22800

22600

22400

22200

22000

21800

21600

21400

Proposed WR365-C Well Location

Proposed WR365-B Well Location

Proposed WR365-A Well Location

2,190,000 2,190,0002,195,000 2,195,0002,200,000 2,200,0002,205,000 2,205,0002,210,000 2,210,0002,215,000

9,630,000

2,215,000

9,630,000

9,635,000 9,635,000

9,640,000 9,640,000

9,645,000 9,645,000

9,650,000 9,650,000

9,655,000 9,655,000

9,660,000 9,660,000

9,665,000 9,665,000

9,670,000 9,670,000

9,675,000 9,675,000 91°14'0"W 91°14'0"W 91°15'0"W 91°15'0"W 91°16'0"W 91°16'0"W 91°17'0"W 91°17'0"W 91°18'0"W 91°18'0"W 91°19'0"W 91°19'0"W 91°20'0"W

26°39'0"N

26°39'0"N

26°38'0"N

26°38'0"N

26°37'0"N

26°37'0"N

26°36'0"N

26°36'0"N

26°35'0"N

26°35'0"N

26°34'0"N

26°34'0"N

26°33'0"N

26°33'0"N

26°32'0"N

26°32'0"N

GEOHAZARD SUMMARY

CHART 17

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

REV DATE REMARKS AUTHOR DRAWN CHECKED

SURVEY DATE N/A REPORT REF 8600 REF NO 8600.17

0 DRAFT JR CM ARH

GEODETIC INFORMATION

Datum Parameters

Datum Name

Ellipsoid

Semi-major Axis

Reciprocal Flattening

NAD27

NAD27

6378137

Projection Method

False Northing

False Easting

Latitude of Origin

Longitude of Origin

Standard Parallel

Scale Factor

Transverse Mercator

0

1640416.666667

0 North

9 East

15 North

0.9996

Map Projection Parameters

Chart Scale 1"=1,000'

0 1,250 2,500 3,750 5,000 6,250 625 Feet

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

Lund Henderson

Lloyd Ridge

Walker Ridge

East Breaks Green Canyon Atwater Valley Garden Banks

Alaminos Canyon Keathley Canyon

Florida Plain

LEGEND

Proposed WR365-A Well Location

(2,199,847ft E / 9,657,944ft N) 3® 3

3

3

Study Area

Not to scale

Proposed WR365-B Well Location

(2,198,491ft E / 9,660,344ft N)

Proposed WR365-C Well Location

(2,200,359ft E / 9,656,793ft N)

3® 3

3

3

3® 3

3

3

Inline

Crossline

Block boundaries

2,00 0ft Radius

2,00 0ft Radius

2,00 0ft Radius

±

Region of seabed favorable for the

development of sensitive sessile benthic

communities

Surficial slump lobe accumulation

Steeply dipping escarpment flanking salt uplift

Localized ridge on top uplift

Fault intersections at seabed. tick denotes downthrown block.

Study area boundary

Unit B - Slight Risk of Gas

Unit C - Slight to locally Moderate Risk of Gas

Unit D - Slight to locally Moderate Risk of Gas

Unit E - Slight to locally Moderate Risk of Gas

Unit B - Moderate Risk of Gas

3D GEOHAZARD ASSESSMENT

GULF OF MEXICO

WALKER RIDGE

BLOCKS 321, 322, 365, 366, 409 & 410

MOLLERUSSA PROSPECT

January 21, 2011

1 May 16, 2011 FINAL JR CM ARH
Repsol E&P USA Inc. Page F-1 

Initial Exploration Plan December, 2011 

Walker Ridge Block 365 (OCS-G 33967)

APPENDIX F 

WASTES AND DISCHARGES INFORMATION 

(A) PROJECTED GENERATED WASTES 

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

is included in this section as Attachment F-1. 
please specify if the amount reported is a total or per well amount

Type of Waste Composition Projected Amount Discharge rate Discharge Method 

Will drilling occur ? If yes, you should list muds and cuttings

Water-based drilling fluid Sea & FW Gel,Lignite Barite 60,000 bbls/well 2,000 bbls/hr Seafloor discharge prior to installation oSynthetic based drilling fluid Synthetic based drilling fluids 1,800 bbls/well 4 bbls/hr (maximum while drilling only)

1,800 bbls/well of synthetic based oil addried drill cuttings will be discharged ovdrilling SBM interval. Cuttings are centpassed through cuttings dryer to reduce to be in compliance with EPA requiremebe shunt through a downpipe to 25' belosurface. Remaining synthetic based drishipped to shore for recycling or dispos

Cuttings wetted with waterbased fluid Drl Cttgs & WBM 2,700 bbls/well 85 bbls/hr (maximum while drilling only) Seafloor discharge prior to installation o

Cuttings wetted with synthetic-based fluid Drl Cttgs & SBM 8,060 bbls/well

40 bbls/hr (maximum while drilling only)

Treated cuttings will be discharged ovedrilling SBM interval. Cuttings are centpassed through cuttings dryer to reduce in compliance with EPA and will then be downpipe to 25' below the water's surfa

Will humans be there? If yes, expect conventional waste

Domestic waste

Gray water from galley, lavatory and laundry 70,000 bbls/well 75 gal/person/day

Treated by 2x100% Hamworthy Super TSewage Treatment Plans, IMO & MED ceaccepted by USCG for non-US flagged vwaters. Discharged through port-side cchute) below sea level. Projected amoumaximum POB of 150.

Sanitary waste

Treated human body waste from toilets 23,500 bbls/well 25 gal/person/day

Treated by 2x100% Hamworthy Super TSewage Treatment Plans, IMO & MED ceaccepted by USCG for non-US flagged vwaters. Discharged through port-side cchute) below sea level. Projected amoumaximum POB of 150.

Is there a deck? If yes, there will be Deck Drainage

Deck Drainage Rainwater and rig washing

45,000 bbls/well (based on 65 

inches/year average rainfall) 10 bbls/hr (dependent on rainfall)

Oily water is treated in one of four sepadischarged through port-side caisson (cbelow sea level)

Will you conduct well treatment, completion, or workover? 

Well treatment fluids NA NA NA NA 

Well completion fluids

Salt solutions, weighted brines, polymers and various additives

10,000 bbl/well 200 bbl/hr Oily water discharge then discharge ove

Workover fluids NA NA NA NA 

Miscellaneous discharges. If yes, only fill in those associated with your activity. 

Desalinization unit discharge

Rejected water from watermaker unit

200,000 bbls/well 31,650 gal/day

Discharged below sea level via port or s(salt water service discharge) Discharge one unit running for 24 consecutive hou

Projected generated waste Projected ocean discharges 

 ATTACHMENT F-1 

WASTES YOU WILL GENERATE, TREAT AND DOWNHOLE DISPOSE OR DISCHAR
Type of Waste Composition Projected Amount Discharge rate Discharge Method 

Projected generated waste Projected ocean discharges 

Blowout preventer fluid

2% solution of Erifon HD603HP BOP control fluid in potable water 1,300 bbls/well 150 bbls/month Discharged at the seafloor.

Ballast water

Uncontaminated seawater used to maintain proper draft. 925,000 bbls/well 3,500 bbls/day

Per MARPOL regulations, discharge belone of four points depending upon whicvessel is being ballasted.

Bilge water NA NA NA NA 

Excess cement at seafloor Cement slurry 500 bbls/well 20 bbls/minute Discharged at the seafloor. Fire water

Seawater with no addition of chemicals 36,000,000 bbls/well 137,000 bbls/day

Discharged below sea level via stern castarboard). Note: Fire water pumps are from salt water service ring (cooling wawater pumps will only discharge when i

Cooling water

Seawater with no addition of chemicals 36,000,000 bbls/well 137,000 bbls/day

Discharged below sea level via stern castarboard). Discharge rate is calculated running for 24 consecutive hours.

Will you produce hydrocarbons? If yes fill in for produced water.

Produced water NA NA NA NA 

Will you be covered by an individual or general NPDES permit ? General NPDES
please specify if the amount reported is a total or per well amount

Type of Waste Composition Projected Amount Discharge rate Discharge M

l drilling occur ? If yes, you should list muds and cuttings

Water-based drilling fluid Sea & FW Gel,Lignite Barite 60,000 bbls/well 2,000 bbls/hr Seafloor discharge prior to instaSynthetic based drilling fluid Synthetic based drilling fluids 1,800 bbls/well 4 bbls/hr (maximum while drilling only)

1,800 bbls/well of synthetic basedried drill cuttings will be dischadrilling SBM interval. Cuttings apassed through cuttings dryer to to be in compliance with EPA rebe shunt through a downpipe to surface. Remaining synthetic bashipped to shore for recycling o

Cuttings wetted with waterbased fluid Drl Cttgs & WBM 2,700 bbls/well 85 bbls/hr (maximum while drilling only) Seafloor discharge prior to insta

Cuttings wetted with synthetic-based fluid Drl Cttgs & SBM 8,060 bbls/well

40 bbls/hr (maximum while drilling only)

Treated cuttings will be dischargdrilling SBM interval. Cuttings apassed through cuttings dryer to in compliance with EPA and will downpipe to 25' below the water

l humans be there? If yes, expect conventional waste

Domestic waste

Gray water from galley, lavatory and laundry 70,000 bbls/well 75 gal/person/day

Treated by 2x100% Hamworthy SSewage Treatment Plans, IMO & accepted by USCG for non-US flwaters. Discharged through porchute) below sea level. Projectemaximum POB of 150.

Sanitary waste

Treated human body waste from toilets 23,500 bbls/well 25 gal/person/day

Treated by 2x100% Hamworthy SSewage Treatment Plans, IMO & accepted by USCG for non-US flwaters. Discharged through porchute) below sea level. Projectemaximum POB of 150.

ere a deck? If yes, there will be Deck Drainage

Deck Drainage Rainwater and rig washing

45,000 bbls/well (based on 65 

inches/year average rainfall) 10 bbls/hr (dependent on rainfall)

Oily water is treated in one of fodischarged through port-side cabelow sea level)

you conduct well treatment, completion, or workover? 

Well treatment fluids NA NA NA NAWell completion fluids

Salt solutions, weighted brines, polymers and various additives

10,000 bbl/well 200 bbl/hr Oily water discharge then discha

Workover fluids NA NA NA NA

cellaneous discharges. If yes, only fill in those associated with your activity. 

Desalinization unit discharge

Rejected water from watermaker unit

200,000 bbls/well 31,650 gal/day

Discharged below sea level via p(salt water service discharge) Dione unit running for 24 consecu

Projected generated waste Projected ocean discharge

 ATTACHMENT F-1 

WASTES YOU WILL GENERATE, TREAT AND DOWNHOLE DISPOSE OR DISC
Type of Waste Composition Projected Amount Discharge rate Discharge M

Projected generated waste Projected ocean discharge

Blowout preventer fluid

2% solution of Erifon HD603HP BOP control fluid in potable water 1,300 bbls/well 150 bbls/month Discharged at the seafloor.

Ballast water

Uncontaminated seawater used to maintain proper draft. 925,000 bbls/well 3,500 bbls/day

Per MARPOL regulations, dischaone of four points depending upvessel is being ballasted.

Bilge water NA NA NA NAExcess cement at seafloor Cement slurry 500 bbls/well 20 bbls/minute Discharged at the seafloor.Fire water

Seawater with no addition of chemicals 36,000,000 bbls/well 137,000 bbls/day

Discharged below sea level via sstarboard). Note: Fire water pufrom salt water service ring (coowater pumps will only discharge 

Cooling water

Seawater with no addition of chemicals 36,000,000 bbls/well 137,000 bbls/day

Discharged below sea level via sstarboard). Discharge rate is carunning for 24 consecutive hour

you produce hydrocarbons? If yes fill in for produced water.

Produced water NA NA NA NA

you be covered by an individual or general NPDES permit ? General NPDES
Repsol E&P USA Inc. Page G-1 

Initial Exploration Plan December, 2011 

Walker Ridge Block 365 (OCS-G 33967)

APPENDIX G 

AIR EMISSIONS INFORMATION 

(A) EMISSIONS WORKSHEETS AND SCREENING QUESTIONS 

 Screen Procedures for EP’s Yes No 

Is any calculated Complex Total (CT) Emission amount (tons) associated with your 

proposed exploration activities more than 90% of the amounts calculated using the 

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

(where D = distance to shore in miles)? 

 X 

Do your emission calculations include any emission reduction measures or modified 

emission factors? X 

Are your proposed exploration activities located east of 87.5° W longitude? X 

Do you expect to encounter H2S at concentrations greater than 20 parts per million (ppm)? X 

Do you propose to flare or vent natural gas for more than 48 continuous hours from any 

proposed well? X 

Do you propose to burn produced hydrocarbon liquids? X 

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

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

the table below. 

Air Pollutant 

Plan 

Emission 

Amounts1

(tons) 

Calculated 

Exemption 

Amounts2

(tons) 

Calculated 

Complex Total 

Emission 

Amounts3

(tons) 

Carbon Monoxide (CO) 1059.51 104502.17 1059.51 

Particular Matter (PM) 141.27 5674.32 141.27 

Sulphur Dioxide (SO2) 648.06 5674.32 648.06 

Nitrogen Oxides (NOx) 4856.07 5674.32 4856.07 

Volatile Organic Compounds (VOC) 145.68 5674.32 145.68 

1

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

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

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

This information was calculated by: Judy Davidson 

 (281) 578-3388 

 Judy.Davidson@jccteam.com
Repsol E&P USA Inc. Page H-1 

Initial Exploration Plan December, 2011 

Walker Ridge Block 365 (OCS-G 33967)

APPENDIX H 

OIL SPILLS INFORMATION 

(A) OIL SPILL RESPONSE PLANNING 

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

approved Oil Spill Response Plan (OSRP) dated May 19, 2009. The last submitted modification 

to that Plan was filed on January 27, 2011 and is currently pending approval. WCD calculations 

were approved in the Initial EP for Green Canyon Block 304 (Control N-9287). 

(B) SPILL RESPONSE SITES 

Primary Response Equipment Location Preplanned Staging Location 

Houma, LA 

Harvey, LA 

Houma, LA 

Harvey, LA 

Fourchon, LA 

(C) OSRO INFORMATION 

Repsol’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. 

(D) WORST-CASE SCENARIO COMPARISON 

Category Regional OSRP 

WCD 

EP 

WCD 

Type of Activity Drilling Drilling 

Facility Location 

(Area/Block) GC 304 WR 365 

Facility Designation A 

Distance to Nearest 

Shoreline (miles) 92 170.4 

Volume 

 Storage Tanks (Total) 

Uncontrolled blowout 

Total Volume 

75,700 51,929 

Type of Oil(s) 

(crude, condensate, diesel) Crude Crude 

API Gravity 28° 28° 

Repsol has determined that the worst-case scenario from the activities proposed in this EP do not 

supersede the worst-case scenario from our approved Regional OSRP.
Repsol E&P USA Inc. Page H-2 

Initial Exploration Plan December, 2011 

Walker Ridge Block 365 (OCS-G 33967)

Since Repsol has the capability to respond to the worst-case spill scenario included in our 

Regional OSRP, and since the worst-case scenario determined for our EP does not replace the 

worst-case scenario in our Regional OSRP, Repsol hereby certifies that Repsol has the capability 

to respond, to the maximum extent practicable, to a worst-case discharge, or a substantial threat 

of such a discharge, resulting from the activities proposed in our EP. 

(E) SPILL RESPONSE DISCUSSION FOR NEPA ANALYSIS 

SPILL RESPONSE DISCUSSION 

For the purpose of NEPA and Coastal Zone Management Act analysis, the largest spill volume 

originating from the proposed activity would be a well blowout during drilling operations, 

estimated to be 51,929 barrels of crude oil with an API gravity of 28°. 

Land Segment and Resource Identification

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

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

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

BSEE OSRAM identifies a 3% probability of impact to the shorelines of Cameron Parish, 

Louisiana within 30 days. Cameron Parish includes the east side of Sabine Lake, Sabine National 

Wildlife Refuge, Calcasieu Lake, Lacassine National Wildlife Refuge and Grand Lake. Cameron 

Parish also includes the area along the coastline from Sabine Pass to Big Constance Lake in 

Rockefeller Wildlife Refuge. This region is composed of open public beaches, marshlands and 

swamps. It serves as a habitat for numerous birds, finfish and other animals, including several 

rare, threatened and endangered species. 

Response

Repsol will make every effort to respond to the Worst Case Discharge as effectively as 

practicable. A description of the response equipment under contract to contain and recover the 

Worst Case Discharge is shown in Figure 2.

Using the estimated chemical and physical characteristics of crude oil, an ADIOS weathering 

model was run on a similar product from the ADIOS oil database. The results indicate 12% or 

approximately 6,231 barrels of crude oil would be evaporated/dispersed within 24 hours, with 

approximately 45,698 barrels remaining. 

Spill Response WR 365, Well A Barrels of Oil 

WCD Volume 51,929 

Less 12% natural evaporation/dispersion 6,231 

Remaining volume 45,698 

Daily dispersant capability 7,540 

Oil addressed by in-situ burning 2,284 
Repsol E&P USA Inc. Page H-3 

Initial Exploration Plan December, 2011 

Walker Ridge Block 365 (OCS-G 33967)

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

storage equipment available to respond to a spill of approximately 45,698 barrels. The volume 

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

individual times needed for procurement, load out, travel time to the site and deployment. Figure 

2 also indicates how operations will be supported. 

Repsol’s Oil Spill Response Plan includes alternative response technologies such as dispersants 

and in-situ burn. Strategies will be decided by Unified Command based on the size of the spill, 

weather and potential impacts. If aerial dispersants are utilized, 8 sorties (9,600 gallons) from 

two of the DC-3 aircrafts and 4 sorties (8,000 gallons) from the Basler aircraft would provide a 

daily dispersant capability of 7,540 barrels. If the conditions are favorable for in-situ burning, the 

proper approvals have been obtained and the proper planning is in place, in-situ burning of oil 

may be attempted. Using estimates based on the Deepwater Horizon spill of 2010, up to 5% or 

approximately 2,284 barrels of the total daily Worst Case Discharge volume could be burned. 

Slick containment boom would be immediately called out and on-scene as soon as possible. 

Offshore response strategies may include attempting to skim utilizing the HOSS Barge, nine Fast 

Response Units, and two sets of Koseq skimming arms, with a total derated skimming capacity 

of 112,588 barrels. Temporary storage associated with skimming equipment equals 9,700 

barrels. If additional storage is needed, a 25,000 barrel storage barge, three 23,000 barrel storage 

barges, and a 20,000 barrel storage barge may be mobilized and centrally located to provide 

temporary storage allowing the skimmers to stay in the area of operations as much as possible. 

Safety is first priority. Air monitoring will be accomplished and operations deemed safe 

prior to any containment/skimming attempts. 

If the spill went unabated, shoreline impact in Cameron Parish, Louisiana would depend upon 

existing environmental conditions. Shoreline protection would include the use of CGA’s near 

shore and shallow water skimmers with a totaled derated skimming capacity of 18,253 barrels. 

Temporary storage associated with skimming equipment equals 1,317 barrels. If additional 

storage is needed, a 20,000 barrel storage barge may be mobilized and centrally located to 

provide temporary storage allowing the skimmers to stay in the area of operations as much as 

possible. Onshore response may include the deployment of shoreline boom on beach areas, or 

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

access to 30,000 feet of 18” shoreline protection boom. Figure 2 outlines individual times 

needed for procurement, load out, travel time to the site and deployment. Strategies would be 

based upon surveillance and real time trajectories that depict areas of potential impact given 

actual sea and weather conditions. The State of Louisiana Initial Oil Spill Response Plan for 

Cameron Parish and Unified Command would be consulted to ensure that environmental and 

special economic resources would be correctly identified and prioritized to ensure optimal 

protection. Shoreline protection strategies depict the protection response modes applicable for oil 

spill clean-up operations. The State of Louisiana Initial Oil Spill Response Plan provides detailed 

shoreline protection strategies for this area, and it describes necessary action to keep the oil spill 

from entering Louisiana’s coastal wetlands, based on the assumption that removal of the released 

oil will be much easier and less damaging to fragile coastal ecosystems if done in the open 

waters of the Gulf of Mexico. Supervisory personnel have the option to modify the deployment 

and operation of equipment allowing a more effective response to site-specific circumstances. 
Repsol E&P USA Inc. Page H-4 

Initial Exploration Plan December, 2011 

Walker Ridge Block 365 (OCS-G 33967)

Repsol’s contract Spill Management Team holds a copy of the State of Louisiana Initial Oil Spill 

Response Plan. 

Based on the anticipated worst case discharge scenario, Repsol can be onsite with contracted oil 

spill recovery equipment with adequate response capacity to contain and recover surface 

hydrocarbons, and prevent land impact, to the maximum extent practicable, within an estimated 

45 hours (based on the equipment’s Effective Daily Recovery Capacity (EDRC)). 

Initial Response Considerations 

Actual actions taken during an oil spill response will be based on many factors which include but 

are not 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 

Repsol will take action to provide a safe, aggressive response to contain and recover as much of 

the spilled oil as quickly as it is safe to do so. In an effort to protect the environment, response 

actions will be designed to provide an “in-depth” protection strategy meant to recover as much 

oil as possible as far from environmentally sensitive areas as possible. Safety will take 

precedence over all other considerations during these operations. 

Upon notification of a spill, the following actions will be taken: 

• Information will be confirmed 

• An assessment will be made and initial objectives set 

• OSROs and appropriate agencies will be notified 

• ICS 201, Initial Report Form will be completed 

• Initial Safety plan will be written and published 

• Unified Command will be established 

o Overall safety plan developed to reflect the operational situation and coordinated 

objectives 

o Areas of responsibility established for Source Control and each surface operational 

site 

o On-site command and control established 

Offshore Response Actions 

Equipment Deployment
Repsol E&P USA Inc. Page H-5 

Initial Exploration Plan December, 2011 

Walker Ridge Block 365 (OCS-G 33967)

Surveillance 

• Surveillance Aircraft will be deployed within two hours of Qualified Individual (QI) 

notification, or at first light

• Provide trained observer to provide on site status reports 

• Provide command and control platform at the site if needed 

• Continual surveillance of oil movement by remote sensing systems, aerial photography 

and visual confirmation 

• Continual monitoring of vessel assets using vessel monitoring systems 

Dispersant application assets 

• Put Airborne Support Inc. (ASI) on standby 

• With the Federal On-Scene Coordinator (FOSC), conduct analysis to determine 

appropriateness of dispersant application 

• Gain FOSC approval for use of dispersants on the surface 

• Deploy aircraft in accordance with a plan developed for the actual situation 

• Coordinate movement of dispersants, aircraft, and support equipment and personnel 

• Confirm dispersant availability for current and long range operations 

• Start ordering dispersant stocks required for expected operations 

Containment boom 

• Call out early and expedite deployment to be on scene ASAP 

• Ensure boom handling and mooring equipment is deployed with boom 

• Provide continuing reports to vessels to expedite their arrival at sites that will provide for 

their most effective containment 

• Use Vessels of Opportunity (VOO) to deploy and maintain boom 

Dedicated off-shore skimming systems 

General 

• Deployed to the highest concentration of oil 

• Assets deployed at safe distance from aerial dispersant and in-situ burn operations 

CGA HOSS Barge 

• Use in areas with heaviest oil concentrations 

• Consider for use in areas of known debris (seaweed, and other floating materials) 

CGA Fast Response Units (FRU) 

• To the area of the thickest oil 

• Use as far off-shore as allowed 

T&T Koseq Skimming Systems 

• To the area of the thickest oil 

• Use as far off-shore as allowed 

• VOOs with a minimum of 2,000 bbls storage capacity 
Repsol E&P USA Inc. Page H-6 

Initial Exploration Plan December, 2011 

Walker Ridge Block 365 (OCS-G 33967)

Storage Vessels 

• Establish availability of CGA contracted assets 

• Early call out (to allow for tug boat acquisition and deployment speeds) 

• Phase mobilization to allow storage vessels to arrive at the same time as skimming 

systems 

• Position as closely as possible to skimming assets to minimize offloading time 

Vessels of Opportunity (VOO) 

• Use Repsol’s contracted resources as applicable 

• Industry vessels are usually best for deployment of Vessel of Opportunity Skimming 

Systems (VOSS) 

• Acquire additional resources as needed 

• Consider use of local assets, i.e. fishing and pleasure craft 

• Expect mission specific and safety training to be required 

• Plan with the US Coast Guard for vessel inspections 

In-situ Burn assets 

• Determine appropriateness of in-situ burn operation in coordination with the FOSC and 

affected State On-Scene Coordinator (SOSC) 

• Determine availability of fire boom and selected ignition systems 

• Start ordering fire boom stocks required for expected operations 

• Contact boom manufacturer to provide training if required 

• Determine assets to perform on water operation 

• Build operations into safety plan 

• Conduct operations in accordance with an approved plan 

Near Shore Response Actions 

Timing 

• Place near shore assets on standby and deploy in accordance with planning based on the 

actual situation, actual trajectories and oil budgets 

• VOO identification and training in advance of spill nearing shoreline if possible 

• Outfitting of VOOs for specific missions 

• Deployment of assets based on actual movement of oil 

Considerations 

• Water depth, vessel draft 

• Shoreline gradient 

• State of the oil 

• Use of VOOs 

• Distance of surf zone from shoreline 
Repsol E&P USA Inc. Page H-7 

Initial Exploration Plan December, 2011 

Walker Ridge Block 365 (OCS-G 33967)

Equipment Deployment 

Surveillance 

• Provide trained observer to direct skimming operations 

• Continual surveillance of oil movement by remote sensing systems, aerial photography 

and visual confirmation 

• Continual monitoring of vessel assets 

Dispersant Use 

• Generally will not be approved within 3 miles of shore or with less than 10 meters of 

water depth 

• Approval would be at Regional Response Team level (Region 6) 

Vessel Deployment 

Dedicated Near Shore skimming systems 

• Fast Response Vessels (FRV) 

• Egmopol and Marco Shallow Water Skimmer (SWS) 

• Operate with aerial spotter directing systems to observed oil slicks 

VOO 

• Use Repsol’s contracted resources as applicable 

• Industry vessels are usually best for deployment of Vessel of Opportunity Skimming 

Systems (VOSS) 

• Acquire additional resources as needed 

• Consider use of local assets, i.e. fishing and pleasure craft 

• Expect mission specific and safety training to be required 

• Plan with the US Coast Guard for vessel inspections 

• Operate with aerial spotter directing systems to oil patches 

Shoreline Protection Operations 

Response Planning Considerations 

• Environmental risk assessments (ERA) to determine priorities for area protection 

• Time to acquire personnel and equipment and their availability 

• Previous contingency planning contained in the appropriate Area Contingency Plan, and 

currently for Louisiana, The State of Louisiana Initial Oil Spill Response Plan, Deep 

Water Horizon, dated 2 May 2010 (La. OSRP) 

Actions 

Placement of boom 

• Position boom in accordance with the ERA based on the actual situation or the 

appropriate ACP 

• Assess timing of booming operations to ensure it is where it needs to be at time of 

impact. Consider: 
Repsol E&P USA Inc. Page H-8 

Initial Exploration Plan December, 2011 

Walker Ridge Block 365 (OCS-G 33967)

o Trajectories 

o Weather forecast 

o Oil Impact forecast 

o Verified spill movement 

o Boom, manpower and vessel (shallow draft) availability 

o Near shore boom and support material, (stakes, anchors, line) 

Beach Preparation 

Considerations and Actions 

• Use of a 10 mile go/no go line to determine timing of beach cleaning 

• Shoreline Cleanup and Assessment Team Reports and recommendations 

• Determination of Archeological sites and gaining authority to enter 

• Monitoring of tide tables and weather to determine extent of high tides 

• Pre cleaning of beaches by moving waste above high tide lines to minimize waste 

• Staging of equipment and housing of response personnel as close to the job site as 

possible to maximize on-site work time 

• Boom tending, repair, replacement and security (use of local assets may be advantageous) 

• Constant awareness of weather and oil movement for resource redeployment as necessary 

• In-situ burn may be considered when marshes have been impacted 

• Passive clean up of marshes should be 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 

 
Repsol E&P USA Inc. Page H-9 

Initial Exploration Plan December, 2011 

Walker Ridge Block 365 (OCS-G 33967)

Decanting Strategy 

Recovered oil and water mixtures will typically separate into distinct phases when left in a 

quiescent state. When separation occurs, the relatively clean water phase can be siphoned or 

decanted back to the recovery point with minimal, if any, impact. Decanting therefore increases 

the effective on-site oil storage capacity and equipment operating time. FOSC/SOSC approval 

will be requested prior to decanting operations. This practice is routinely used for oil spill 

recovery. 

CGA Equipment Limitations 

The capability for any spill response equipment, whether a dedicated or portable system, to 

operate in differing weather conditions will be directly in relation to the capabilities of the vessel 

the system in placed on. Most importantly, however, the decision to operate will be based on the 

judgment of the Unified Command and/or the Captain of the vessel, who will ultimately have the 

final say in terminating operations. Skimming equipment listed below may have operational 

limits which exceed those safety thresholds. As was seen in the Deepwater Horizon (DWH) oil 

spill response, vessel skimming operations ceased when seas reached 5-6 feet and vessels were 

often recalled to port when those conditions were exceeded. Systems below are some of the 

most up-to-date systems available and were employed during the DWH spill. 

Boom 3 foot seas, 20 knot winds 

Dispersants Winds more than 25 knots 

Visibility less than 3 nautical miles 

Ceiling less than 1,000 feet. 

FRU 8 foot seas 

HOSS Barge/OSRB 8 foot seas 

Koseq Arms 8 foot seas 

OSRV 4 foot seas 

 
Repsol E&P USA Inc. Page H-10 

Initial Exploration Plan December, 2011 

Walker Ridge Block 365 (OCS-G 33967)

Environmental Conditions in the GOM

Louisiana is situated between the easterly and westerly wind belts, and therefore, experiences 

westerly winds during the winter and easterly winds in the summer. Average wind speed is 

generally 14-15 mph along the coast. Wave heights average 4 and 5 feet. However, during 

hurricane season, Louisiana has recorded wave heights ranging from 40 to 50 feet high and 

winds reaching speeds of 100 mph. Because much of southern Louisiana lies below sea level, 

flooding is prominent. 

Surface water temperature ranges between 70 and 80 ̊F during the summer months. During the 

winter, the average temperature will range from 50 and 60 ̊F. 

The Atlantic and Gulf of Mexico hurricane season is officially from 1 June to 30 December. 97% 

of all tropical activity occurs within this window. The Atlantic basin shows a very peaked season 

from August through October, with 78% of the tropical storm days, 87% of the minor (SaffirSimpson Scale categories 1 and 2) hurricane days, and 96% of the major (Saffir-Simpson 

categories 3, 4 and 5) hurricane days occurring then. Maximum activity is in early to mid 

September. Once in a few years there may be a hurricane occurring "out of season" - primarily in 

May or December. Globally, September is the most active month and May is the least active 

month. 

 
Repsol E&P USA Inc. Page H-11 

Initial Exploration Plan December, 2011 

Walker Ridge Block 365 (OCS-G 33967)

FIGURE 1 

TRAJECTORY BY LAND SEGMENT 

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

utilizing Repsol’s WCD and information in the BSEE Oil Spill Risk Analysis Model 

(OSRAM) for the Central and Western Gulf of Mexico available on the BSEE website 

using 30 day impact. The results are tabulated below. 

Area/Block OCS-G Launch 

Area 

Land Segment and/or 

Resource 

Conditional 

Probability (%) 

within 30 days 

Drill and complete 3 

wells 

WR 365, Well A 

170.4 miles from shore 

G33967 C47 Matagorda County, TX 

Brazoria County, TX 

Galveston County, TX 

Jefferson County, TX 

Cameron Parish, LA 

Vermilion Parish, LA 

Terrebonne Parish, LA 

Plaquemines Parish, LA 

1 

1 

2 

1 

3 

1 

1 

1 
Repsol E&P USA Inc. Page H-12 

Initial Exploration Plan December, 2011 Walker Ridge Block 365 (OCS-G 33967)WCD Scenario– BASED ON WELL BLOWOUT DURING DRILLING OPERATIONS (170.4 miles f

45,698 bbls of crude oil (Volume considering natural weathering) 

API Gravity 28° 

FIGURE 2 – Equipment Response Time to WR 365, Well A 

Dispersants/Surveillance 

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

site 

CGA 

Basler 67T 2000 NA 2 Houma 1 1 1.1 

ASI 

DC 3 1200 NA 2 Houma 1 1 1.4 DC 3 1200 NA 2 Houma 1 1 1.4 Aero Commander NA NA 2 Houma 1 1 1.1 

Offshore Response 

Offshore Equipment No 

Staging EDRC Storage Capacity VOO Persons Required From Hrs to Procure Hrs to Loadout Hrs to GOM 

CGA 

HOSS Barge 43000 4000 3 Tugs 8 Harvey 7 0 5 

T&T Marine (available through contract with CGA) 

Koseq Skimming Arms (2) 35658 4000 2 Utility 12 Leeville 1 12 2 

Recovered Oil Storage No 

Staging EDRC Storage Capacity VOO Persons Required From Hrs to Procure Hrs to Loadout Hrs to GOM 

Enterprise Marine Services LLC (available through contract with CGA) 

CTCo 2603 NA 25000 1 Tug 6 Amelia 4 12 4 CTCo 2604 NA 20000 1 Tug 6 Amelia 4 12 4 CTCo 2607 NA 23000 1 Tug 6 Amelia 4 12 4 CTCo 2608 NA 23000 1 Tug 6 Amelia 4 12 4 CTCo 2609 NA 23000 1 Tug 6 Amelia 4 12 4 
Repsol E&P USA Inc. Page H-13 

Initial Exploration Plan December, 2011 Walker Ridge Block 365 (OCS-G 33967)

Staging Area: Fourchon

Offshore Equipment With 

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

CGA 

FRU (1) + 100 bbl Tank (2) 3770 200 1 Utility 6 Belle Chasse 1 2 2.5 FRU (1) + 100 bbl Tank (2) 3770 200 1 Utility 6 Galveston 1 2 7 FRU (3) + 100 bbl Tank (5) 11310 500 1 Utility 6 Houma 1 2 1 FRU (1) + 100 bbl Tank (2) 3770 200 1 Utility 6 Ingleside 1 2 9.5 FRU (1) + 100 bbl Tank (2) 3770 200 1 Utility 6 Lake Charles 1 2 4 FRU (2) + 100 bbl Tank (4) 7540 400 1 Utility 6 Venice 1 2 4 

Offshore Equipment With 

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

CGA 

42” Auto Boom (5000’) NA NA 10 Crew 20 Belle Chasse 1 2 2.5 42” Auto Boom (5000’) NA NA 10 Crew 20 Galveston 1 2 7 42” Auto Boom (5000’) NA NA 10 Crew 20 Houma 1 2 1 42” Auto Boom (2500’) NA NA 6 Crew 12 Ingleside 1 2 9.5 42” Auto Boom (5000’) NA NA 10 Crew 20 Lake Charles 1 2 4 42” Auto Boom (2500’) NA NA 6 Crew 12 Pascagoula 1 2 4 1000’ Hydro-Fire Boom NA NA 8 Utility 40 Harvey 1 4 2 
Repsol E&P USA Inc. Page H-14 

Initial Exploration Plan December, 2011 Walker Ridge Block 365 (OCS-G 33967)

Nearshore Response 

Nearshore Equipment No 

Staging EDRC Storage Capacity VOO Persons Required From Hrs to Procure Hrs to Loadout Hrs to GOM 

CGA 

46’ FRV 5000 65 NA 4 Lake Charles 1 0 1 

Enterprise Marine Services LLC (available through contract with CGA) 

CTCo 2605 NA 20000 1 Tug 6 Amelia 4 12 4 

Staging Area: Cameron 

Nearshore and Inland 

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

CGA 

SWS Egmopol 3000 100 NA 3 Galveston 1 2 3.5 SWS Egmopol 3000 100 NA 3 Houma 1 2 4 SWS Marco 3588 34 NA 3 Houma 1 2 4 SWS Marco 3588 20 NA 3 Lake Charles 1 2 1 Rope Mop 77 2 0 3 Belle Chasse 1 2 4.5 RO Storage Barge NA 249 Towed 0 Galveston 1 2 3.5 RO Storage Barge NA 249 Towed 0 Houma 1 2 4 RO Storage Barge NA 249 Towed 0 Lake Charles 1 2 1 RO Storage Barge NA 249 Towed 0 Venice 1 2 6.5 
Repsol E&P USA Inc. Page H-15 

Initial Exploration Plan December, 2011 Walker Ridge Block 365 (OCS-G 33967)

Shoreline Protection 

Staging Area: Cameron 

Shoreline Protection 

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

Oil Mop (available through Letter of Intent) 

10,000’ 18” Boom 4 Crew 10 New Iberia, LA 1 1 2.5 2 10,000’ 18” Boom 4 Crew 10 Houston, TX 1 1 2.5 2 10,000’ 18” Boom 4 Crew 10 Port Arthur, TX 1 1 1.25 2 

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

CGA 

Beach Boom (2000’) NA NA NA 6 Galveston 1 2 3.5 Beach Boom (1000’) NA NA NA 4 Ingleside 1 2 6 Beach Boom (2000’) NA NA NA 6 Pascagoula 1 2 5.5 

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

CGA 

Wildlife Support Trailer NA NA NA 2 Houma 1 2 4 Bird Scare Guns (24) NA NA NA 2 Belle Chasse 1 2 4.5 Bird Scare Guns (12) NA NA NA 2 Galveston 1 2 3.5 Bird Scare Guns (24) NA NA NA 2 Houma 1 2 4 Bird Scare Guns (12) NA NA NA 2 Ingleside 1 2 6 Bird Scare Guns (24) NA NA NA 2 Lake Charles 1 2 1 Bird Scare Guns (24) NA NA NA 2 Pascagoula 1 2 5.5 

Response Asset Total 

Offshore EDRC 112,588 Offshore Recovered Oil Storage 123,700 Nearshore / Shallow Water EDRC 18,253 Nearshore / Shallow Water Recovered Oil Storage 21,317 
Repsol E&P USA Inc. Page I-1 

Initial Exploration Plan December, 2011 

Walker Ridge Block 365 (OCS-G 33967)

APPENDIX I 

ENVIRONMENTAL MONITORING INFORMATION 

(A) MONITORING SYSTEMS 

Repsol will visually observe the sea, monitor fluid volumes and pressures to determine if there 

are any leaks, will monitor the wellhead area subsea with an ROV, monitor surface gas detectors, 

current meters and visual observation of the sea surface from the rig and from support vessels. 

(B) INCIDENTAL TAKES 

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

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

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

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

(C) FLOWER GARDEN BANKS NATIONAL MARINE SANCTUARY 

Walker Ridge Block 365 is not located in the Flower Garden Banks National Marine Sanctuary; 

therefore, the requested information is not required in this EP. 
Repsol E&P USA Inc. Page J-1 

Initial Exploration Plan December, 2011 

Walker Ridge Block 365 (OCS-G 33967)

APPENDIX J 

LEASE STIPULATIONS INFORMATION 

Exploration activities are subject to the following stipulation attached to Lease OCS-G 33967 

Walker Ridge Block 365. 

Marine Protected Species

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

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

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

of intentional and/or accidental introduction of debris into the marine environment.
Repsol E&P USA Inc. Page L-1 

Initial Exploration Plan December, 2011 

Walker Ridge Block 365 (OCS-G 33967)

APPENDIX K 

ENVIRONMENTAL MITIGATION MEASURES INFORMATION 

(A) INCIDENTAL TAKES

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

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

conducted herein: 

• NTL 2007-G04, “Vessel Strike Avoidance and Injured/Dead Protected Species 

Reporting” 

• NTL 2007-G03, “Marine Trash and Debris Awareness and Elimination” 

• NTL 2007-G02, “Implementation of Seismic Survey Mitigation Measures and Protected 

Species Observer Program” 
Repsol E&P USA Inc. Page L-2 

Initial Exploration Plan December, 2011 

Walker Ridge Block 365 (OCS-G 33967)

APPENDIX L 

SUPPORT VESSELS AND AIRCRAFT INFORMATION 

(A) GENERAL 

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

conditions will be utilized. 

Type Maximum Fuel 

Tank Capacity 

Maximum 

Number in Area 

at Any Time 

Trip 

Frequency or 

Duration 

Crew Boat 23,500 gallons 1 4/week 

Supply Boat 280,000 gallons 1 2/week 

Helicopters 412 gallons 1 7/week 

(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’ 1,500 gallons 3/month 

Shortest route from 

Fourchon, LA to Walker 

Ridge Block 365 

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

(D) SOLID AND LIQUID WASTE TRANSPORTATION 

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

Attachment L-1. 

(E) VICINITY MAP 

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

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

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

the onshore support facilities and the drilling unit. 

 
please specify whether the amount reported is a total or per wel

Solid and Liquid Wastes 

transportation 

Type of Waste Composition Transport Method Name/Location of Facility 

Will drilling occur ? If yes, fill in the muds and cuttings.

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

Spent synthetic based drilling fluids Cutting boxes on supply boat

US Liquids, Fourchon, LA or Newpark Environmental, Fourchon, LA. 

Synthetic-based drilling fluid or mud Used synthetic based drilling fluids Drums or tanks on supply boat MI Swaco, Fourchon, LA 

Cuttings wetted with Water-based fluid Drl Cttgs & WBM NA NA 

Cuttings wetted with Synthetic-based fluid Drl Cttgs & SBM NA NA 

Cuttings wetted with oil-based fluids NA NA NA 

Will you produce hydrocarbons? If yes fill in for produced sand.

Produced sand NA NA NA Trash and debris (non-recyclable)

Non-recyclable nonhazardous trash and debris Storage bins on supply boat Martin Terminal/Sweede, Fourchon, LA 

Recyclable trash and debris

Recyclable non-hazardous trash and debris Bags or storage bins on supply boat Techoil, New Iberia, LA. 

Recyclable trash and debris

Batteries, glass, lamp and light tubes

Vendor supplied DOT storage bins 

on supply vessel then trucked to vendor facility.

American Recovery, 

Houma, LA. 

Used oil

Used oil, oil filters, rags, pads, empty drums, cooking oil

Vendor supplied DOT storage bins 

on supply vessel then trucked to vendor facility.

American Recovery, 

Houma, LA.

Tank wash water NA NA NA 

Chemical product wastes

Paints, solvents, unused chemicals, etc.

Vendor supplied DOT storage bins 

on supply vessel then trucked to vendor facility.

American Recovery, 

Houma, LA. 

NOTE: If you will not have a type of waste, enter NA in the row. 

ATTACHMENT L-1 

WASTES YOU WILL TRANSPORT AND /OR DISPOSE OF ONSHO

Was

Will you have additional wastes that are not permitted for discharge? If yes, fill in the appropriate rows. 

Projected generated waste
!!

!!

!!

!!

!!

!!

!! !!

Green Canyon

Walker Ridge Lund

Ship Shoal

Atwater Valley

South Timbalier

Mississippi Canyon

Eugene Island

Ewing Bank

West Delta

Ship Shoal South

Grand Isle

South Timbalier South

West Delta South

South Pelto

Fourchon

Cocodrie

Grand Isle

River Ridge

Terrebonne Lafourche

Plaquemines

Jefferson

Repsol E&P USA Inc. Vicinity Map

Walker Ridge 365

WR365

~170.4

Miles to

S

h

ore

~186

Miles

to

Fourchon, LA

Shorebase
Repsol E&P USA Inc. Page M-1 

Initial Exploration Plan December, 2011 

Walker Ridge Block 365 (OCS-G 33967)

APPENDIX M 

ONSHORE SUPPORT FACILITIES INFORMATION 

(A) GENERAL 

Name of Shorebase Location Existing/New/Modified 

C-Port 2 Port Fourchon, LA Existing 

(B) SUPPORT BASE CONSTRUCTION OR EXPANSION 

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

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

(C) SUPPORT BASE CONSTRUCTION OR EXPANSION TIMETABLE 

Not applicable to this plan. 

(D) WASTE DISPOSAL 

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

Attachment L-1.
Repsol E&P USA Inc. Page N-1 

Initial Exploration Plan December, 2011 

Walker Ridge Block 365 (OCS-G 33967)

APPENDIX N 

COASTAL ZONE MANAGEMENT (CZMA) INFORMATION 

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

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

Attachment N-1. 


TEXAS 

As authorized by the Federal Coastal Zone Management Act (CZMA), the State of Texas 

developed a Coastal Management Program (CMP) to allow for the review of proposed Federal 

license and permit activities affecting any coastal use or resource, in or outside of the Texas 

Coastal Zone. 

The OCS related oil and gas exploratory and development activities having potential impact on 

the Texas Coastal Zone are based on the location of the proposed facilities, access to those sites, 

best practical techniques for drilling locations, drilling equipment guidelines for the prevention 

of adverse environmental effects, effective environmental protection, emergency plans and 

contingency plans. 

Below are topics found in other sections of the plan and have been cross referenced for ease in 

locating: 

Topic Cross Reference Comments 

Construction, Operation and Maintenance of Oil and Gas 

Exploration and Production Facilities 

APPENDIX A These are exploratory operations, therefore, 

no construction of facilities is proposed. 

Discharges of Wastewater and Disposal of Waste from Oil 

and Gas Exploration and Production Activities 

APPENDIX F and L No discharges are proposed in Texas 

waters. 

Construction and Operation of Solid Waste Treatment, 

Storage, and Disposal Facilities 

APPENDIX L No construction of solid waste, treatment or 

storage facilities is proposed. 

Prevention, Response, and Remediation of Oil Spills APPENDIX H 

Discharge of Municipal and Industrial Waste Water to 

Coastal Waters 

APPENDIX F and L No discharges are proposed in Texas 

waters. 

Development in Critical Areas APPENDIX E 

Construction of Waterfront Facilities and Other Structures 

on Submerge lands 

APPENDIX L 

Dredging and Dredged Material Disposal and Placement APPENDIX H 

Construction in the Beach / Dune System APPENDIX H 

Alteration of Coastal Historic Areas APPENDIX H 

Transportation APPENDIX L 

Emission of Air Pollutants APPENDIX G 

Appropriations of Water There will be no fresh water appropriations 

as a result of our operations 

Marine Fishery Management APPENDIX E 

Administrative Policies Proposed operations are 170 miles offshore, 

therefore, not subject to Section 501.15 

regarding major actions 
Repsol E&P USA Inc. Page O-1 

Initial Exploration Plan December, 2011 

Walker Ridge Block 365 (OCS-G 33967)

APPENDIX O 

ENVIRONMENTAL IMPACT ANALYSIS (EIA) 

Repsol E&P USA Inc. (Repsol)

Initial Exploration Plan 

Walker Ridge Block 365 

OCS-G 33967

(A) IMPACT PRODUCING FACTORS 

ENVIRONMENTAL IMPACT ANALYSIS WORKSHEET 

Environment 

Resources 

Impact Producing Factors (IPFs) 

Categories and Examples 

Refer to recent GOM OCS Lease Sale EIS for a more complete list of IPFs 

Emissions 

(air, noise, 

light, etc.) 

Effluents 

(muds, 

cutting, other 

discharges to 

the water 

column or 

seafloor) 

Physical 

disturbances to the 

seafloor (rig or 

anchor 

emplacements, 

etc.) 

Wastes sent 

to shore for 

treatment 

or disposal 

Accidents 

(e.g., oil 

spills, 

chemical 

spills, H2S 

releases) 

Discarded 

Trash & 

Debris 

Site-specific at Offshore Location 

Designated topographic features (1) (1) (1) 

Pinnacle Trend area live bottoms (2) (2) (2) 

Eastern Gulf live bottoms (3) (3) (3) 

Benthic communities (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 
Repsol E&P USA Inc. Page O-2 

Initial Exploration Plan December, 2011 

Walker Ridge Block 365 (OCS-G 33967)

Footnotes for Environmental Impact Analysis Matrix 

Activities that may affect a marine sanctuary or topographic feature. Specifically, if the well or platform site or any anchors

will be on the seafloor within the: 

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

1000-m, 1-mile or 3-mile zone of any topographic feature (submarine bank) protected by the Topographic Features 

Stipulation attached to an OCS lease; 

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

Proximity of any submarine bank (500 ft. buffer zone) with relief greater than 2 meters that is not protected by the 

Topographic Features Stipulation attached to an OCS lease. 

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

Stipulation attached to an OCS lease. 

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

Stipulation attached to an OCS lease. 

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

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

All activities that could result in an accidental spill of produced liquid hydrocarbons or diesel fuel that you determine would

impact these environmental resources. If the proposed action is located a sufficient distance from a resource that no 

impact would occur, the EIA can note that in a sentence or two. 

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

BOEM as having high-probability for the occurrence of shipwrecks or prehistoric sites, including such blocks that will 

be affected that are adjacent to the lease block in which your planned activity will occur. If the proposed activities are 

located a sufficient distance from a shipwreck or a prehistoric site that no impact would occur, the EIA can note that in 

a sentence or two. 

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

or their critical habitats. 

Production activities that involve transportation of produced fluids to shore using shuttle tankers or barges. 
Repsol E&P USA Inc. Page O-3 

Initial Exploration Plan December, 2011 

Walker Ridge Block 365 (OCS-G 33967)

(B) Analysis 

Site-Specific at Walker Ridge Block 365 

Proposed operations consist of the drilling, testing, and completion of 3 wells. 

The operations will be conducted with a DP semisubmersible. 

1. Designated Topographic Features 

Potential IPFs on topographic features include effluents, and accidents. 

Effluents: Walker Ridge Block 365 is 92 miles from the closest designated Topographic Features 

Stipulation Block (Sweet Bank); therefore, no adverse impacts are expected. 

Accidents: It is unlikely that an accidental surface or subsurface spill would occur from the proposed 

activities (refer to statistics in Item 5, Water Quality). Oil spills cause damage to benthic organisms 

only if the oil contacts the organisms. Oil from a surface spill can be driven into the water column; 

measurable amounts have been documented down to a 10 m depth. At this depth, the oil is found only 

at concentrations several orders of magnitude lower than the amount shown to have an effect on corals. 

Because the crests of topographic features in the Northern Gulf of Mexico are found below 10 m, no 

oil from a surface spill could reach their sessile biota. Oil from a subsurface spill is not applicable due 

to the distance of these blocks from a topographic area. The activities proposed in this plan will be 

covered by Repsol’s Regional OSRP (refer to information submitted in Appendix H). 

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

shore for disposal) from the proposed activities, which could impact topographic features. 

2. Pinnacle Trend Area Live Bottoms 

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

Effluents: Walker Ridge Block 365 is 252 miles from the closest live bottom (pinnacle trend) area; 

therefore, no adverse impacts are expected. 

Accidents: It is unlikely that an accidental surface or subsurface spill would occur from the proposed 

activities (refer to statistics in Item 5, Water Quality). Oil spills have the potential to foul benthic 

communities and cause lethal and sublethal effects on live bottom organisms. Oil from a surface spill 

can be driven into the water column; measurable amounts have been documented down to a 10 m 

depth. At this depth, the oil is found only at concentrations several orders of magnitude lower than the 

amount shown to have an effect on marine organisms. Oil from a subsurface spill is not applicable due 

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

plan will be covered by Repsol’s Regional OSRP (refer to information submitted in Appendix H). 
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There are no other IPFs (including emissions, physical disturbances to the seafloor and wastes sent to 

shore for disposal) from the proposed activities which could impact a live bottom (pinnacle trend) area. 

3. Eastern Gulf Live Bottoms 

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

Effluents: Walker Ridge Block 365 is not located in an area characterized by the existence of live 

bottoms; therefore, no adverse impacts are expected. 

Accidents: It is unlikely that an accidental surface or subsurface spill would occur from the proposed 

activities (refer to statistics in Item 5, Water Quality). Oil spills cause damage to live bottom 

organisms only if the oil contacts the organisms. Oil from a surface spill can be driven into the water 

column; measurable amounts have been documented down to a 10 m depth. At this depth, the oil is 

found only at concentrations several orders of magnitude lower than the amount shown to have an 

effect on marine invertebrates. Oil from a subsurface spill is not applicable due to the distance of these 

blocks from a live bottom area. The activities proposed in this plan will be covered by Repsol’s 

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

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

shore for disposal) from the proposed activities which could impact an Eastern Gulf live bottom area. 

4. Benthic Communities 

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

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

A DP semisubmersible is being used for the proposed activities; therefore, only an insignificant 

amount of seafloor will be disturbed. Because physical disturbances to the seafloor will be minimized 

by the use of a DP semisubmersible, Repsol’s proposed operations in Walker Ridge Block 365 would 

not cause impacts to benthic communities. 

5. Water Quality 

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

Block 365 include effluents and accidents. 

 

Effluents: Levels of contaminants in drilling muds and cuttings and produced water discharges, 

discharge-rate restrictions and monitoring and toxicity testing are regulated by the EPA NPDES 

permit, thereby eliminating many significant biological or ecological effects. Operational discharges 

are not expected to cause significant adverse impacts to water quality. 
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Accidents: Oil spills have the potential to alter offshore water quality; however, it is unlikely that an 

accidental surface or subsurface spill would occur from the proposed activities. Between 1980 and 

2000, OCS operations produced 4.7 billion barrels of oil and spilled only 0.001 percent of this oil, or 1 

bbl for every 81,000 bbl produced. The spill risk related to a diesel spill from drilling operations is 

even less. Between 1976 and 1985, (years for which data were collected), there were 80 reported 

diesel spills greater than one barrel associated with drilling activities. Considering that there were 

11,944 wells drilled, this is a 0.7 percent probability of an occurrence. If a spill were to occur, the 

water quality of marine waters would be temporarily affected by the dissolved components and small 

oil droplets. Dispersion by currents and microbial degradation would remove the oil from the water 

column and dilute the constituents to background levels. Historically, changes in offshore water quality 

from oil spills have only been detected during the life of the spill and up to several months afterwards. 

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

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

Appendix H). 

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

shore for disposal) from the proposed activities which could cause impacts to water quality. 

6. Fisheries 

IPFs that could cause impacts to fisheries as a result of the proposed operations in Walker Ridge Block 

365 include effluents and accidents. 

Effluents: Effluents such as drilling fluids and cuttings discharges contain components and properties 

which are detrimental to fishery resources. Moderate petroleum and metal contamination of sediments 

and the water column can occur out to several hundred meters down-current from the discharge point. 

Offshore discharges are expected to disperse and dilute to very near background levels in the water 

column or on the seafloor within 3,000 m of the discharge point, and are expected to have negligible 

effect on fisheries. 

Accidents: An accidental oil spill has the potential to cause some detrimental effects on fisheries; 

however, it is unlikely that such an event would occur from the proposed activities (refer to Item 5, 

Water Quality). The effects of oil on mobile adult finfish or shellfish would likely be sublethal and the 

extent of damage would be reduced to the capacity of adult fish and shellfish to avoid the spill, to 

metabolize hydrocarbons, and to excrete both metabolites and parent compounds. The activities 

proposed in this plan will be covered by Repsol’s Regional OSRP (refer to information submitted in 

Appendix H). 

There are no IPFs from emissions, physical disturbances to the seafloor or wastes sent to shore for 

disposal from the proposed activities which could cause impacts to fisheries. 
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7. Marine Mammals 

GulfCet II studies revealed that cetaceans of the continental shelf and shelf-edge were almost 

exclusively bottlenose dolphin and Atlantic spotted dolphin. Squid eaters, including dwarf and pygmy 

killer whale, Risso’s dolphin, rough-toothed dolphin, and Cuvier’s beaked whale, occurred most 

frequently along the upper slope in areas outside of anticyclones. IPFs that could cause impacts to 

marine mammals as a result of the proposed operations in Walker Ridge Block 365 include emissions, 

effluents, discarded trash and debris, and accidents. 

Emissions: Noises from drilling activities, support vessels and helicopters may elicit a startle reaction 

from marine mammals. This reaction may lead to disruption of marine mammals’ normal activities. 

Stress may make them more vulnerable to parasites, disease, environmental contaminants, and/or 

predation (Majors and Myrick, 1990). There is little conclusive evidence for long-term displacements 

and population trends for marine mammals relative to noise. 

Effluents: Drilling fluids and cuttings discharges contain components which may be detrimental to 

marine mammals. Most operational discharges are diluted and dispersed upon release. Any potential 

impact from drilling fluids would be indirect, either as a result of impacts on prey items or possibly 

through ingestion in the food chain (API, 1989). 

Discarded trash and debris: Both entanglement in, and ingestion of debris have caused the death or 

serious injury of marine mammals (Laist, 1997; MMC, 1999). The limited amount of marine debris, if 

any, resulting from the proposed activities is not expected to substantially harm marine mammals. 

Operators are prohibited from deliberately discharging debris as mandated by MARPOL-Annex V and 

the Marine Plastic Pollution Research and Control Act, and regulations imposed by various agencies 

including the United States Coast Guard (USCG) and the Environmental Protection Agency (EPA). 

Repsol will operate in accordance with the regulations and also avoid accidental loss of solid waste 

items by maintaining waste management plans, manifesting trash sent to shore, and using special 

precautions such as covering outside trash bins to prevent accidental loss of solid waste. Special 

caution will be exercised when handling and disposing of small items and packaging materials, 

particularly those made of non-biodegradable, environmentally persistent materials such as plastic or 

glass. 

Informational placards will be posted on all vessels and facilities having sleeping or food preparation 

capabilities. All offshore personnel, including contractors and other support services-related personnel 

(e.g. helicopter pilots, vessel captains and boat crews) will be indoctrinated on waste procedures, and 

will view the video (or Microsoft PowerPoint presentation), “Think About It” (previously “All Washed 

Up: The Beach Litter Problem”). Thereafter, all personnel will view the marine trash and debris 

training video annually. Offshore personnel will also receive an explanation from Repsol management 

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

in accordance with NTL No. 2007-G03. 
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Accidents: Collisions between support vessels and cetaceans would be unusual events, however 

should one occur, death or injury to marine mammals is possible. Contract vessel operators can avoid 

marine mammals and reduce potential deaths by maintaining a vigilant watch for marine mammals and 

maintaining a safe distance when they are sighted. Vessel crews should use a reference guide to help 

identify the twenty-eight species of whales and dolphins, and the single species of manatee that may be 

encountered in the Gulf of Mexico OCS. Vessel crews must report sightings of any injured or dead 

protected marine mammal species immediately, regardless of whether the injury or death is caused by 

their vessel, to the Marine Mammal and Sea Turtle Stranding Hotline at (888) 404-3922, the NMFS 

Southeast Regional Office at (727) 824-5312, or the Marine Mammal Stranding Network at (305) 862-

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

must be notified within 24 hours of the strike by email to protectedspecies@boemre.gov. If the vessel 

is the responsible party, it is required to remain available to assist the respective salvage and stranding 

network as needed. 

Oil spills have the potential to cause sublethal oil-related injuries and spill-related deaths to marine 

mammals. However, it is unlikely that an accidental oil spill would occur from the proposed activities 

(refer to Item 5, Water Quality). Oil spill response activities may increase vessel traffic in the area, 

which could add to changes in cetacean behavior and/or distribution, thereby causing additional stress 

to the animals. The effect of oil dispersants on cetaceans is not known. The acute toxicity of oil 

dispersant chemicals included in Repsol’s OSRP is considered to be low when compared with the 

constituents and fractions of crude oils and diesel products. The activities proposed in this plan will be 

covered by Repsol’s OSRP (refer to information submitted in accordance with Appendix H). 

There are no other IPFs (including physical disturbances to the seafloor) from the proposed activities 

which could impact marine mammals. 

8. Sea Turtles 

IPFs that could cause impacts to sea turtles as a result of the proposed operations include emissions, 

effluents, discarded trash and debris, and accidents. GulfCet II studies sighted most loggerhead, 

Kemp’s ridley and leatherback sea turtles over shelf waters. Historically these species have been 

sighted up to the shelf’s edge. They appear to be more abundant east of the Mississippi River than 

they are west of the river (Fritts et al., 1983b; Lohoefener et al., 1990). Deep waters may be used by all 

species as a transitory habitat. 

Emissions: Noise from drilling activities, support vessels, and helicopters may elicit a startle reaction 

from sea turtles, but this is a temporary disturbance. 

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). 
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Discarded trash and debris: Both entanglement in, and ingestion of, debris have caused the death or 

serious injury of sea turtles (Balazs, 1985). The limited amount of marine debris, if any, resulting from 

the proposed activities is not expected to substantially harm sea turtles. Operators are prohibited from 

deliberately discharging debris as mandated by MARPOL-Annex V and the Marine Plastic Pollution 

Research and Control Act, and regulations imposed by various agencies including the United States 

Coast Guard (USCG) and the Environmental Protection Agency (EPA). Repsol will operate in 

accordance with the regulations and also avoid accidental loss of solid waste items by maintaining 

waste management plans, manifesting trash sent to shore, and using special precautions such as 

covering outside trash bins to prevent accidental loss of solid waste. Special caution will be exercised 

when handling and disposing of small items and packaging materials, particularly those made of nonbiodegradable, environmentally persistent materials such as plastic or glass. 

Informational placards will be posted on all vessels and facilities having sleeping or food preparation 

capabilities. All offshore personnel, including contractors and other support services-related personnel 

(e.g. helicopter pilots, vessel captains and boat crews) will be indoctrinated on waste procedures, and 

will view the video (or Microsoft PowerPoint presentation), “Think About It” (previously “All Washed 

Up: The Beach Litter Problem”). Thereafter, all personnel will view the marine trash and debris 

training video annually. Offshore personnel will also receive an explanation from Repsol management 

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

in accordance with NTL No. 2007-G03. 

Accidents: Collisions between support vessels and sea turtles would be unusual events, however 

should one occur, death or injury to sea turtles is possible. Contract vessel operators can avoid sea 

turtles and reduce potential deaths by maintaining a vigilant watch for sea turtles and maintaining a 

safe distance when they are sighted. Vessel crews should use a reference guide to help identify the 

five species of sea turtles that may be encountered in the Gulf of Mexico OCS. Vessel crews must 

report sightings of any injured or dead protected sea turtle species immediately, regardless of whether 

the injury or death is caused by their vessel, to the Marine Mammal and Sea Turtle Stranding Hotline 

at (888) 404-3922, the NMFS Southeast Regional Office at (727) 824-5312, or the Marine Mammal 

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

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

protectedspecies@boemre.gov. If the vessel is the responsible party, it is required to remain available 

to assist the respective salvage and stranding network as needed. 

All sea turtle species and their life stages are vulnerable to the harmful effects of oil through direct 

contact or by fouling of their food. Exposure to oil can be fatal, particularly to juveniles and hatchlings. 

However, it is unlikely that an accidental oil spill would occur from the proposed activities (refer to 

Item 5, Water Quality). Oil spill response activities may increase vessel traffic in the area, which could 

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

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

Appendix H). 
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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 365 is beyond the 200 kilometer 

(124 mile) buffer for the Breton Wilderness Area and is 170.4 miles from the coastline. Therefore, no 

special mitigation, monitoring, or reporting requirements apply with respect to air emissions. 

Accidents and blowouts can release hydrocarbons or chemicals, which could cause the emission of air 

pollutants. However, these releases would not impact onshore air quality because of the prevailing 

atmospheric conditions, emission height, emission rates, and the distance of Walker Ridge Block 365 

from the coastline. There are no other IPFs (including effluents, physical disturbances to the seafloor, 

wastes sent to shore for treatment or disposal) from the proposed activities which could impact air 

quality. 

10. Shipwreck Sites (known or potential) 

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

operations in Walker Ridge Block 365 include disturbances to the seafloor. 

Physical disturbances to the seafloor: A DP semisubmersible is being used for the proposed 

activities; therefore, only an insignificant amount of seafloor will be disturbed. Because physical 

disturbances to the seafloor will be minimized by the use of a DP semisubmersible, Repsol’s proposed 

operations in Walker Ridge Block 365 would not cause impacts to shipwreck sites. 

Additionally, Walker Ridge Block 365 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. 

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

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

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

seafloor archaeological resources, including historic shipwrecks. Copies of the certifications and a 

circle radius plat of the survey area will be submitted to the BOEM. Should a resource be encountered, 

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

that cultural resource. 

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

or accidents) from the proposed activities that could cause impacts to shipwreck sites. 
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11. Prehistoric Archaeological Sites 

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

operations in Walker Ridge Block 365 include disturbances to the seafloor. 

Physical disturbances to the seafloor: A DP semisubmersible is being used for the proposed 

activities; therefore, only an insignificant amount of seafloor will be disturbed. Because physical 

disturbances to the seafloor will be minimized by the use of a DP semisubmersible, Repsol’s proposed 

operations in Walker Ridge Block 365 would not cause impacts to prehistoric archaeological sites. 

Repsol will perform an AUV/ROV survey imaging 100% of the seafloor with sector scanning sonar 

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

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

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

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

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

Additionally, Walker Ridge Block 365 is located outside the Archaeological Prehistoric high 

probability line, therefore, no adverse impacts are expected. 

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

or accidents) from the proposed activities which could impact prehistoric archeological sites. 

Vicinity of Offshore Location 

1. Essential Fish Habitat (EFH) 

IPFs that could cause impacts to EFH as a result of the proposed operations in Walker Ridge Block 

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

Gulf of Mexico. 

Effluents: The Live Bottom Low Relief Stipulation, the Live Bottom (Pinnacle Trend) Stipulation, 

and the Eastern Gulf Pinnacle Trend Stipulation would prevent most of the potential impacts on livebottom communities and EFH from operational waste discharges. Levels of contaminants in drilling 

muds and cuttings and produced-water discharges, discharge-rate restrictions, and monitoring and 

toxicity testing are regulated by the EPA NPDES permit, thereby eliminating many significant 

biological or ecological effects. Operational discharges are not expected to cause significant adverse 

impacts to EFH. 

Accidents: An accidental oil spill has the potential to cause some detrimental effects on EFH. Oil 

spills that contact coastal bays and estuaries, as well as OCS waters when pelagic eggs and larvae are 

present, have the greatest potential to affect fisheries. However, it is unlikely that an oil spill would 
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occur from the proposed activities (refer to Item 5, Water Quality). The activities proposed in this plan 

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

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

shore for treatment or disposal) from the proposed activities which could impact essential fish habitat. 

2. Marine and Pelagic Birds 

IPFs that could impact marine birds as a result of the proposed activities include air emissions, 

accidental oil spills, and discarded trash and debris from vessels and the facilities. 

Emissions: Emissions of pollutants into the atmosphere from these activities are far below 

concentrations which could harm coastal and marine birds. 

Accidents: An oil spill would cause localized, low-level petroleum hydrocarbon contamination. 

However, it is unlikely that an oil spill would occur from the proposed activities (refer to Item 5, 

Water Quality). Marine and pelagic birds feeding at the spill location may experience chronic, 

nonfatal, physiological stress. It is expected that few, if any, coastal and marine birds would actually 

be affected to that extent. The activities proposed in this plan will be covered by Repsol’s Regional 

OSRP (refer to information submitted in Appendix H). 

Discarded trash and debris: Marine and pelagic birds could become entangled and snared in 

discarded trash and debris, or ingest small plastic debris, which can cause permanent injuries and 

death. Operators are prohibited from deliberately discharging debris as mandated by MARPOL-Annex 

V and the Marine Plastic Pollution Research and Control Act, and regulations imposed by various 

agencies including the United States Coast Guard (USCG) and the Environmental Protection Agency 

(EPA). Repsol will operate in accordance with the regulations and also avoid accidental loss of solid 

waste items by maintaining waste management plans, manifesting trash sent to shore, and using special 

precautions such as covering outside trash bins to prevent accidental loss of solid waste. Special 

caution will be exercised when handling and disposing of small items and packaging materials, 

particularly those made of non-biodegradable, environmentally persistent materials such as plastic or 

glass. Informational placards will be posted on all vessels and facilities having sleeping or food 

preparation capabilities. All offshore personnel, including contractors and other support servicesrelated personnel (e.g. helicopter pilots, vessel captains and boat crews) will be indoctrinated on waste 

procedures, and will view the video (or Microsoft PowerPoint presentation), “Think About It” 

(previously “All Washed Up: The Beach Litter Problem”). Thereafter, all personnel will view the 

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

from Repsol management or the designated lease operator management that emphasizes their 

commitment to waste management in accordance with NTL No. 2007-G03. Debris, if any, from these 

proposed activities will seldom interact with marine and pelagic birds; therefore, the effects will be 

negligible. 
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Walker Ridge Block 365 (OCS-G 33967)

There are no other IPFs (including effluents, physical disturbances to the seafloor, or wastes sent to 

shore for treatment or disposal) from the proposed activities which could impact marine and pelagic 

birds. 

3. Public Health and Safety Due to Accidents. 

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

treatment or disposal or accidents, including an accidental H2S release) from the proposed activities 

which could cause impacts to public health and safety. In accordance with NTL No.’s 2008-G04, 

2009-G27, and 2009-G31, sufficient information is included in Appendix D to justify our request that 

our proposed activities be classified by BSEE as H2S absent. 

Coastal and Onshore 

1. Beaches 

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

discarded trash and debris. 

Accidents: Oil spills contacting beaches would have impacts on the use of recreational beaches and 

associated resources. Due to the distance from shore (170.4 miles) and the response capabilities that 

would be implemented, no significant adverse impacts are expected. The activities proposed in this 

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

Discarded trash and debris: Trash on the beach is recognized as a major threat to the enjoyment and 

use of beaches. There will only be a limited amount of marine debris, if any, resulting from the 

proposed activities. Operators are prohibited from deliberately discharging debris as mandated by 

MARPOL-Annex V and the Marine Plastic Pollution Research and Control Act, and regulations 

imposed by various agencies including the United States Coast Guard (USCG) and the Environmental 

Protection Agency (EPA). Repsol will operate in accordance with the regulations and also avoid 

accidental loss of solid waste items by maintaining waste management plans, manifesting trash sent to 

shore, and using special precautions such as covering outside trash bins to prevent accidental loss of 

solid waste. Special caution will be exercised when handling and disposing of small items and 

packaging materials, particularly those made of non-biodegradable, environmentally persistent 

materials such as plastic or glass. 

Informational placards will be posted on all vessels and facilities having sleeping or food preparation 

capabilities. All offshore personnel, including contractors and other support services-related personnel 

(e.g. helicopter pilots, vessel captains and boat crews) will be indoctrinated on waste procedures, and 

will view the video (or Microsoft PowerPoint presentation), “Think About It” (previously “All Washed 

Up: The Beach Litter Problem”). Thereafter, all personnel will view the marine trash and debris 

training video annually. Offshore personnel will also receive an explanation from Repsol management 
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Walker Ridge Block 365 (OCS-G 33967)

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

in accordance with NTL No. 2007-G03. 

There are no other IPFs (emissions, effluents, physical disturbances to the seafloor, or wastes sent to 

shore for treatment or disposal) from the proposed activities which could impact beaches. 

2. Wetlands 

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

discarded trash and debris. 

Accidents: It is unlikely that an oil spill would occur from the proposed activities (refer to Item 5, 

Water Quality). Due to the distance from shore (170.4 miles) and the response capabilities that would 

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

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

Discarded trash and debris: There will only be a limited amount of marine debris, if any, resulting 

from the proposed activities. Operators are prohibited from deliberately discharging debris as 

mandated by MARPOL-Annex V and the Marine Plastic Pollution Research and Control Act, and 

regulations imposed by various agencies including the United States Coast Guard (USCG) and the 

Environmental Protection Agency (EPA). Repsol will operate in accordance with the regulations and 

also avoid accidental loss of solid waste items by maintaining waste management plans, manifesting 

trash sent to shore, and using special precautions such as covering outside trash bins to prevent 

accidental loss of solid waste. Special caution will be exercised when handling and disposing of small 

items and packaging materials, particularly those made of non-biodegradable, environmentally 

persistent materials such as plastic or glass. 

Informational placards will be posted on all vessels and facilities having sleeping or food preparation 

capabilities. All offshore personnel, including contractors and other support services-related personnel 

(e.g. helicopter pilots, vessel captains and boat crews) will be indoctrinated on waste procedures, and 

will view the video (or Microsoft PowerPoint presentation), “Think About It” (previously “All Washed 

Up: The Beach Litter Problem”). Thereafter, all personnel will view the marine trash and debris 

training video annually. Offshore personnel will also receive an explanation from Repsol management 

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

in accordance with NTL No. 2007-G03. 

There are no other IPFs (emissions, effluents, physical disturbances to the seafloor, or wastes sent to 

shore for treatment or disposal) from the proposed activities which could impact wetlands. 
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Walker Ridge Block 365 (OCS-G 33967)

3. Shore Birds and Coastal Nesting Birds 

Accidents: Oil spills could cause impacts to shore birds and coastal nesting birds. However, it is 

unlikely that an oil spill would occur from the proposed activities (refer to Item 5, Water Quality). 

Given the distance from shore (170.4 miles) and the response capabilities that would be implemented, 

no impacts are expected. The activities proposed in this plan will be covered by Repsol’s Regional 

OSRP (refer to information submitted in Appendix H). 

Discarded trash and debris: Coastal and marine birds are highly susceptible to entanglement in 

floating, submerged, and beached marine debris: specifically plastics. Operators are prohibited from 

deliberately discharging debris as mandated by MARPOL-Annex V and the Marine Plastic Pollution 

Research and Control Act, and regulations imposed by various agencies including the United States 

Coast Guard (USCG) and the Environmental Protection Agency (EPA). Repsol will operate in 

accordance with the regulations and also avoid accidental loss of solid waste items by maintaining 

waste management plans, manifesting trash sent to shore, and using special precautions such as 

covering outside trash bins to prevent accidental loss of solid waste. Special caution will be exercised 

when handling and disposing of small items and packaging materials, particularly those made of nonbiodegradable, environmentally persistent materials such as plastic or glass. 

 

Informational placards will be posted on vessels and every facility that has sleeping or food 

preparation capabilities. All offshore personnel, including contractors and other support servicesrelated personnel (e.g. helicopter pilots, vessel captains and boat crews) will be indoctrinated on waste 

procedures, and will view the video (or Microsoft PowerPoint presentation), “Think About It” 

(previously “All Washed Up: The Beach Litter Problem”). Thereafter, all personnel will view the 

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

from Repsol management or the designated lease operator management that emphasizes their 

commitment to waste management in accordance with NTL No. 2007-G03. 

There are no other IPFs (emissions, effluents, physical disturbances to the seafloor, or wastes sent to 

shore for treatment or disposal) from the proposed activities that could cause impacts to shore birds 

and coastal nesting birds. 

4. Coastal Wildlife Refuges 

Accidents: An accidental oil spill from the proposed activities could cause impacts to coastal wildlife 

refuges. However, it is unlikely that an oil spill would occur from the proposed activities (refer to Item 

5, Water Quality). Due to the distance from shore (170.4 miles) and the response capabilities that 

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

by Repsol’s Regional OSRP (refer to information submitted in Appendix H). 

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

mandated by MARPOL-Annex V, the Marine Plastic Pollution Research and Control Act and 

regulations imposed by various agencies including the United States Coast Guard (USCG) and the 

Environmental Protection Agency (EPA). Repsol will operate in accordance with the regulations and 

also avoid accidental loss of solid waste items by maintaining waste management plans, manifesting 
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Walker Ridge Block 365 (OCS-G 33967)

trash sent to shore, and using special precautions such as covering outside trash bins to prevent 

accidental loss of solid waste. Special caution will be exercised when handling and disposing of small 

items and packaging materials, particularly those made of non-biodegradable, environmentally 

persistent materials such as plastic or glass. 

 

Informational placards will be posted on vessels and every facility that has sleeping or food 

preparation capabilities. All offshore personnel, including contractors and other support servicesrelated personnel (e.g. helicopter pilots, vessel captains and boat crews) will be indoctrinated on waste 

procedures, and will view the video (or Microsoft PowerPoint presentation), “Think About It” 

(previously “All Washed Up: The Beach Litter Problem”). Thereafter, all personnel will view the 

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

from Repsol management or the designated lease operator management that emphasizes their 

commitment to waste management in accordance with NTL No. 2007-G03. 

There are no other IPFs (emissions, effluents, physical disturbances to the seafloor, or wastes sent to 

shore for treatment or disposal) from the proposed activities that could cause impacts to coastal 

wildlife refuges. 

5. Wilderness Areas 

Accidents: An accidental oil spill from the proposed activities could cause impacts to wilderness 

areas. However, it is unlikely that an oil spill would occur from the proposed activities (refer to Item 5, 

Water Quality). Due to the distance from the nearest designated Wilderness Area (235 miles) and the 

response capabilities that would be implemented, no significant adverse impacts are expected. The 

activities proposed in this plan will be covered by Repsol’s Regional OSRP (refer to information 

submitted in Appendix H).

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

mandated by MARPOL-Annex V, the Marine Plastic Pollution Research and Control Act and 

regulations imposed by various agencies including the United States Coast Guard (USCG) and the 

Environmental Protection Agency (EPA). Repsol will operate in accordance with the regulations and 

also avoid accidental loss of solid waste items by maintaining waste management plans, manifesting 

trash sent to shore, and using special precautions such as covering outside trash bins to prevent 

accidental loss of solid waste. Special caution will be exercised when handling and disposing of small 

items and packaging materials, particularly those made of non-biodegradable, environmentally 

persistent materials such as plastic or glass. 

 

Informational placards will be posted on vessels and every facility that has sleeping or food 

preparation capabilities. All offshore personnel, including contractors and other support servicesrelated personnel (e.g. helicopter pilots, vessel captains and boat crews) will be indoctrinated on waste 

procedures, and will view the video (or Microsoft PowerPoint presentation), “Think About It” 

(previously “All Washed Up: The Beach Litter Problem”). Thereafter, all personnel will view the 

marine trash and debris training video annually. Offshore personnel will also receive an explanation 
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Initial Exploration Plan December, 2011 

Walker Ridge Block 365 (OCS-G 33967)

from Repsol management or the designated lease operator management that emphasizes their 

commitment to waste management in accordance with NTL No. 2007-G03. 

There are no other IPFs (emissions, effluents, physical disturbances to the seafloor, or wastes sent to 

shore for treatment or disposal) from the proposed activities that could cause impacts to wilderness 

areas. 

6. Other Environmental Resources Identified 

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

(C) IMPACTS ON PROPOSED ACTIVITIES 

The site–specific environmental conditions have been taken into account for the proposed activities. 

No impacts are expected on the proposed activities from site-specific environmental conditions. 

(D) ENVIRONMENTAL HAZARDS 

During the hurricane season, June through December, the Gulf of Mexico is impacted by an average of 

ten tropical storms (39-73 mph winds), of which six become hurricanes ( > 74 mph winds). Due to its 

location in the gulf, Walker Ridge Block 365 may experience hurricane and tropical storm force winds, 

and related sea currents. These factors can adversely impact the integrity of the operations covered by 

this plan. A significant storm may present physical hazards to operators and vessels, damage 

exploration or production equipment, or result in the release of hazardous materials (including 

hydrocarbons). Additionally, the displacement of equipment may disrupt the local benthic habitat and 

pose a threat to local species. 

The following preventative measures included in this plan may be implemented to mitigate these 

impacts: 

1. Drilling & completion 

a. Secure well 

b. Secure rig / platform 

c. Evacuate personnel 

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

N10. 

2. Structure Installation 

 Operator will not conduct structure installation operations during Tropical Storm or 

 Hurricane threat. 

(E) ALTERNATIVES 

No alternatives to the proposed activities were considered to reduce environmental impacts. 
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Walker Ridge Block 365 (OCS-G 33967)

(F) MITIGATION MEASURES 

No mitigation measures other than those required by regulation will be employed to avoid, diminish, or 

eliminate potential impacts on environmental resources. 

(G) CONSULTATION 

No agencies or persons were consulted regarding potential impacts associated with the proposed 

activities. Therefore, a list of such entities has not been provided. 

(H) PREPARER(S) 

Evan Connolly 

J. Connor Consulting, Inc. 

16225 Park Ten Place, Suite 700 

Houston, TX 77084 

(281) 578-3388 

Evan.connolly@jccteam.com 

(I) REFERENCES 

Authors: 

American Petroleum Institute (API). 1989. Effects of offshore petroleum operations on cold water 

marine mammals: a literature review. Washington, DC: American Petroleum Institute. 385 pp. 

Balazs, G.H. 1985. Impact of ocean debris on marine turtles: entanglement and ingestion. In: Shomura, 

R.S. and H.O. Yoshida, eds. Proceedings, Workshop on the Fate and Impact of Marine Debris, 26-

29 December 1984, Honolulu, HI. U.S. Dept. of Commerce. NOAA Tech. Memo. NOAA-TMNMFS-SWFC-54. Pp 387-429. 

Burke, C.J. and J.A. Veil. 1995. Potential benefits from regulatory consideration of synthetic drilling 

muds. Environmental Assessment Division, Argonne National Laboratory, ANL/EAD/TM-43. 

Daly, J.M. 1997. Controlling the discharge of synthetic-based drilling fluid contaminated cuttings in 

waters of the United States. U.S. Environmental Protection Agency, Office of Water. Work Plan, 

June 24, 1997. 

Hansen, D.J. 198l. The relative sensitivity of seabird populations in Alaska to oil pollution. U.S. Dept. 

of the Interior, Bureau of Land Management, Alaska OCS Region, Anchorage. BLM-YK-ES-81-

006-1792. 
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Initial Exploration Plan December, 2011 

Walker Ridge Block 365 (OCS-G 33967)

Laist, D.W. 1997. Impacts of marine debris: entanglement of marine life in marine debris including a 

comprehensive list of species with entanglement and ingestion records. In: Coe, J.M. and D.B. 

Rogers, eds. Marine debris: sources, impacts, and solutions. New York, NY: Springer-Verlag. Pp. 

99-139. 

Majors, A.P. and A.C. Myrick, Jr. 1990. Effects of noise on animals: implications for dolphins exposed 

to seal bombs in the eastern tropical Pacific purse-seine fishery–an annotated bibliography. NOAA 

Administrative Report LJ-90-06. 

Marine Mammal Commission. 1999. Annual report to Congress – 1998. 

Piatt, J.F., C.J. Lensink, W. Butler, M. Kendziorek, and D.R. Nysewander. 1990. Immediate impact 

of the Exxon Valdez oil spill on marine birds. The Auk. 107 (2): 387-397. 

Vauk , G., E. Hartwig, B. Reineking, and E. Vauk-Hentzelt. 1989. Losses of seabirds by oil pollution 

at the German North Sea coast. Topics in Marine Biology. Ros, J.D, ed. Scient. Mar. 53 (2-3): 749-

754. 

Vermeer, K. and R. Vermeer, 1975 Oil threat to birds on the Canadian west coast. The Canadian 

Field-Naturalist. 89:278-298. 

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

Hazard Surveys 

BOEM EIS’s: 

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

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

Statement. BOEM 96-0058. 
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APPENDIX P 

ADMINISTRATIVE INFORMATION 

(A) EXEMPTED INFORMATION DESCRIPTION 

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

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

data, and any interpreted geology. 

(B) BIBLIOGRAPHY 

Not applicable.