UNITED STATES GOVERNMENT MEMORANDUM

To: Public Information (MS 5030)

Plans Section, Office of Field 

Operations (MS 5231)

Public Information copy of Exploration Plan

Control # - R-05089

Type - Revised Exploration Plan

Lease(s) - OCS-G32700 Block - 675 Walker Ridge Area

OCS-G32704 Block - 719 Walker Ridge Area

Operator - Eni US Operating Co. Inc.

Subsea Wells A, B, C, D, E, & G (WR 719) and F (WR 675)

Not Found

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

should be addressed in an Environmental Assessment.

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

Karen Dunlap

Plan Coordinator

Description -

Rig Type -

Subject:

From:

June 7, 2011

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REVISED 

 EXPLORATION PLAN 

(Control No. R-5089) 

WALKER RIDGE BLOCKS 675 AND 719 

LEASES OCS-G 32700 & 32704 

PUBLIC INFORMATION COPY 

Submitted by: 

eni us operating co. inc. 
ENI US OPERATING CO. INC. 

REVISED EXPLORATION PLAN 

LEASES OCS-G 32700 & 32704 

 WALKER RIDGE 675 & 719 

SECTION A.............................................Plan Contents..................................Page 1 

SECTION B.....................................General Information...............................Pages 2-3

SECTION C................Geological, Geophysical Information....................................Page 4

SECTION D..........................................H2S Information..................................Page 5 

SECTION E.............Biological, Physical and Socioeconomic Information.....................Page 6

SECTION F.....................Wastes and Discharge Information.................................Page 7

SECTION G..............................Air Emissions Information...................................Page 8

SECTION H....................................Oil Spills Information............................Page 9 - 21

SECTION I.................Environmental Monitoring Information................................Page 22 

SECTION J...........................Lease Stipulations Information...............................Page 23 

SECTION K...............Environmental Mitigation Measures Information....................Page 24 

SECTION L...............Support Vessels and Aircraft Information................................Page 25 

SECTION M...............Onshore Support Facilities Information...............................Page 26 

SECTION N...........Coastal Zone Management Act (CZMA) Information...................Page 27 

SECTION O...........................Environmental Impact Analysis.............................Page 28

SECTION P................................Administrative Information.............................Page 29 
Eni US Operating Co. Inc. Page 1 

Revised Exploration Plan (Control No. R-5089) DECEMBER 1, 2010 

Walker Ridge 675 & 719 (OCS-G 32700 & 32704)

SECTION A 

PLAN CONTENTS 

(a) Plan Information Form

No wells have been drilled at this time, a previously approved Exploration Plan, Control No. N-9509 covered the 

drilling and completion of Well Locations “A” to “G”, no additional changes to this section. 

(b) Location

Previously provided and approved under Plan Control No. N-9509, under “Contents of Plan” item (B). 

(c) Safety and Pollution Prevention Features

All reference to this section was previously provided and approved under Plan Control No. N-9509, under “Contents 

of Plan” item (C) only addition is Eni will be utilizing a subsurface BOP stack to conduct the drilling operations 

under this plan. 

(d) Storage Tanks and/or Production Vessels 

Previously provided and approved under Plan Control No. N-9509, under “Contents of Plan” item (D) and will 

remain the same.

(e) Pollution Prevention Measures

Pollution prevention measures include installation of curbs, gutters, drip pans, and drains on drilling deck areas to 

collect all contaminants and debris. 

(f) Additional Measures

Eni does not propose additional safety, pollution prevention, or early spill detection measures beyond those required 

by 30 CFR 250. 
U.S. Department of the Interior OMB Control Number: 1010-0151 

Minerals Management Service OMB Approval Expires: 12/31/2011

OCS PLAN INFORMATION FORM 

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

ATTACHMENT A-1

GENERAL INFORMATION 

Type of OCS Plan: X Revised Exploration Plan 

(EP) – R-5089 

 Development Operations Coordination Document (DOCD) 

Company Name: Eni US Operating Co., Inc. BOEMRE Operator Number: 02782 

Address: 1201 Louisiana, Suite 3500 Contact Person: Brenda Montalvo 

Houston, Texas 77002 Phone Number: (713) 393-6259 

Email Address: 

Lease(s):G32700/32704 Area: WR Block(s): 675/719 Project Name (If Applicable): PHINISI 

Objective(s): Oil Gas Sulphur Salt Onshore Base: Fourchon, LA Distance to Closest Land (Miles): 193 

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 a BOEMRE-designated high-probability archaeological area? Yes X No 

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

Tentative Schedule of Proposed Activities 

Proposed Activity Start 

Date 

End 

Date 

No. of Days 

Drill Location A 01/01/11 05/01/11 120 days 

Drill Location B 11/01/11 02/29/12 120 days 

Drill Location C 11/01/12 03/01/13 120 days 

Drill Location D 11/01/13 03/01/14 120 days 

Complete Locations A,B,C & D 05/01/14 12/31/14 240 days 

Drill Locations E, F, & G contingent on Locations A, B, C, & D 11/01/15 10/26/16 360 days 

Complete Locations E, F, & G Contingent on Locations A, B, C & D 01/01/17 06/30/17 180 days 

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 

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

Proposed Well/Structure Location 

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

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

Surface Location Bottom-Hole Location (For Wells) 

Lease No. OCS-G 32704 

Area Name Walker Ridge 

Block No. 719 

Blockline N/S Departure: 6634’ FNL 

Departures 

(in feet) E/W Departure: 7410’ FWL 

Lambert X-Y X: 2,225,010’ 

coordinates 

Y: 9529046’ 

Latitude/ Latitude: 26° 15’ 00.824” 

Longitude 

Longitude: -91° 12’ 57.423” 

 TVD (Feet): MD (Feet): Water Depth (Feet): 6838’

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 = 

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

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

Coordination Document submitted for BOEMRE approval. We use the information to facilitate our review and data entry 

for OCS plans. We will protect proprietary data according to the Freedom of Information Act and 30 CFR 250.196. An 

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

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

reporting burden for this form is included in the burden for preparing Exploration Plans and Development Operations 

Coordination Documents. We estimate that burden to average 580 hours per response, including the time for reviewing 

instructions, gathering and maintaining data, and completing and reviewing the form. Direct comments regarding the burden 

estimate or any other aspect of this form to the Information Collection Clearance Officer, Mail Stop 4230, Bureau of Ocean 

Energy Management Regulation & Enforcement, 1849 C Street, N.W., Washington, DC 20240. 
OCS PLAN INFORMATION FORM (CONTINUED) 

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

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

Proposed Well/Structure Location 

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

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

Surface Location Bottom-Hole Location (For Wells) 

Lease No. OCS-G 32704 

Area Name Walker Ridge 

Block No. 719 

Blockline N/S Departure: 4462’ FNL 

Departures 

(in feet) E/W Departure: 5921’ FWL 

Lambert X-Y X: 2,223,521’ 

coordinates 

Y: 9,531,218’ 

Latitude/ Latitude: 26° 15’ 22.538” 

Longitude 

Longitude: -91° 13’ 13.448” 

 TVD (Feet): MD (Feet): Water Depth (Feet): 6,829’ 

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 = 

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

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

Coordination Document submitted for BOEMRE approval. We use the information to facilitate our review and data entry 

for OCS plans. We will protect proprietary data according to the Freedom of Information Act and 30 CFR 250.196. An 

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

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

reporting burden for this form is included in the burden for preparing Exploration Plans and Development Operations 

Coordination Documents. We estimate that burden to average 580 hours per response, including the time for reviewing 

instructions, gathering and maintaining data, and completing and reviewing the form. Direct comments regarding the burden 

estimate or any other aspect of this form to the Information Collection Clearance Officer, Mail Stop 4230, Bureau of Ocean 

Energy Management Regulation & Enforcement, 1849 C Street, N.W., Washington, DC 20240. 
OCS PLAN INFORMATION FORM (CONTINUED) 

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

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

Proposed Well/Structure Location 

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

Anchor Radius (if applicable) in feet: Yes No 

Surface Location Bottom-Hole Location (For Wells) 

Lease No. OCS-G 32704 

Area Name Walker Ridge 

Block No. 719 

Blockline N/S Departure: 494’ FNL 

Departures 

(in feet) E/W Departure: 832’ FWL 

Lambert X-Y X: 2218432’ 

coordinates 

Y: 9535186’ 

Latitude/ Latitude: 26° 16’ 02.525” 

Longitude 

Longitude: -91° 14’ 08.745” 

 TVD (Feet): MD (Feet): Water Depth (Feet): 6,907’ 

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 = 

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

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

Coordination Document submitted for BOEMRE approval. We use the information to facilitate our review and data entry 

for OCS plans. We will protect proprietary data according to the Freedom of Information Act and 30 CFR 250.196. An 

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

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

reporting burden for this form is included in the burden for preparing Exploration Plans and Development Operations 

Coordination Documents. We estimate that burden to average 580 hours per response, including the time for reviewing 

instructions, gathering and maintaining data, and completing and reviewing the form. Direct comments regarding the burden 

estimate or any other aspect of this form to the Information Collection Clearance Officer, Mail Stop 4230, Bureau of Ocean 

Energy Management Regulation & Enforcement, 1849 C Street, N.W., Washington, DC 20240. 
OCS PLAN INFORMATION FORM (CONTINUED) 

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

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

Proposed Well/Structure Location 

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

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

Surface Location Bottom-Hole Location (For Wells) 

Lease No. OCS-G 32704 

Area Name Walker Ridge 

Block No. 719 

Blockline N/S Departure: 6,468’ FNL 

Departures 

(in feet) E/W Departure: 2,978’ FWL 

Lambert X-Y X: 2,220,578’ 

coordinates 

Y: 9,529,212’ 

Latitude/ Latitude: 26°15’ 03.071” 

Longitude 

Longitude: -91° 13’ 46.072” 

 TVD (Feet): MD (Feet): Water Depth (Feet): 6,923’ 

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 = 

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

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

Coordination Document submitted for BOEMRE approval. We use the information to facilitate our review and data entry 

for OCS plans. We will protect proprietary data according to the Freedom of Information Act and 30 CFR 250.196. An 

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

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

reporting burden for this form is included in the burden for preparing Exploration Plans and Development Operations 

Coordination Documents. We estimate that burden to average 580 hours per response, including the time for reviewing 

instructions, gathering and maintaining data, and completing and reviewing the form. Direct comments regarding the burden 

estimate or any other aspect of this form to the Information Collection Clearance Officer, Mail Stop 4230, Bureau of Ocean 

Energy Management Regulation & Enforcement, 1849 C Street, N.W., Washington, DC 20240. 
OCS PLAN INFORMATION FORM (CONTINUED) 

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

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

Proposed Well/Structure Location 

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

Anchor Radius (if applicable) in feet: Yes No 

Surface Location Bottom-Hole Location (For Wells) 

Lease No. OCS-G 32704 

Area Name Walker Ridge 

Block No. 719 

Blockline N/S Departure: 4,606’ FNL 

Departures 

(in feet) E/W Departure: 858’ FWL 

Lambert X-Y X: 2,218,458’ 

coordinates 

Y: 9,531,074’ 

Latitude/ Latitude: 26° 15’ 21.798” 

Longitude 

Longitude: -91° 14’ 09.075” 

 TVD (Feet): MD (Feet): Water Depth (Feet): 6,919’ 

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 = 

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

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

Coordination Document submitted for BOEMRE approval. We use the information to facilitate our review and data entry 

for OCS plans. We will protect proprietary data according to the Freedom of Information Act and 30 CFR 250.196. An 

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

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

reporting burden for this form is included in the burden for preparing Exploration Plans and Development Operations 

Coordination Documents. We estimate that burden to average 580 hours per response, including the time for reviewing 

instructions, gathering and maintaining data, and completing and reviewing the form. Direct comments regarding the burden 

estimate or any other aspect of this form to the Information Collection Clearance Officer, Mail Stop 4230, Bureau of Ocean 

Energy Management Regulation & Enforcement, 1849 C Street, N.W., Washington, DC 20240. 
OCS PLAN INFORMATION FORM (CONTINUED) 

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

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

Proposed Well/Structure Location 

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

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

Surface Location Bottom-Hole Location (For Wells) 

Lease No. OCS-G 32700 

Area Name Walker Ridge 

Block No. 675 

Blockline N/S Departure: 2,933’ FSL 

Departures 

(in feet) E/W Departure: 6,515’FEL 

Lambert X-Y X: 2,226,926’ 

coordinates 

Y: 9,538,613’ 

Latitude/ Latitude: 26° 16’ 35.309” 

Longitude 

Longitude: -91° 12’ 34.929” 

 TVD (Feet): MD (Feet): Water Depth (Feet): 7,031’ 

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 = 

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

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

Coordination Document submitted for BOEMRE approval. We use the information to facilitate our review and data entry 

for OCS plans. We will protect proprietary data according to the Freedom of Information Act and 30 CFR 250.196. An 

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

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

reporting burden for this form is included in the burden for preparing Exploration Plans and Development Operations 

Coordination Documents. We estimate that burden to average 580 hours per response, including the time for reviewing 

instructions, gathering and maintaining data, and completing and reviewing the form. Direct comments regarding the burden 

estimate or any other aspect of this form to the Information Collection Clearance Officer, Mail Stop 4230, Bureau of Ocean 

Energy Management Regulation & Enforcement, 1849 C Street, N.W., Washington, DC 20240. 
OCS PLAN INFORMATION FORM (CONTINUED) 

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

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

Proposed Well/Structure Location 

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

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

Surface Location Bottom-Hole Location (For Wells) 

Lease No. OCS-G 32704 

Area Name Walker Ridge 

Block No. 719 

Blockline N/S Departure: 3,726’ FNL 

Departures 

(in feet) E/W Departure: 1,933’ FEL 

Lambert X-Y X: 2,234,507’ 

coordinates 

Y: 9,531,954’ 

Latitude/ Latitude: 26° 15’ 28.732” 

Longitude 

Longitude: -91° 11’ 45.628” 

 TVD (Feet): MD (Feet): Water Depth (Feet): 7,031’

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 = 

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

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

Coordination Document submitted for BOEMRE approval. We use the information to facilitate our review and data entry 

for OCS plans. We will protect proprietary data according to the Freedom of Information Act and 30 CFR 250.196. An 

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

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

reporting burden for this form is included in the burden for preparing Exploration Plans and Development Operations 

Coordination Documents. We estimate that burden to average 580 hours per response, including the time for reviewing 

instructions, gathering and maintaining data, and completing and reviewing the form. Direct comments regarding the burden 

estimate or any other aspect of this form to the Information Collection Clearance Officer, Mail Stop 4230, Bureau of Ocean 

Energy Management Regulation & Enforcement, 1849 C Street, N.W., Washington, DC 20240. 
Eni US Operating Co. Inc. Page 2

Revised Exploration Plan (Control No. R-5089) DECEMBER 1, 2010 

Walker Ridge 675 & 719 (OCS-G 32700 & 32704)

SECTION B 

GENERAL INFORMATION 

(a) Applications and Permits

No additional applications or permits from other agencies are required at this time to be submitted and approved 

other than an Application for Permit to Drill (APD) to the appropriate BOEMRE District. 

(b) Drilling Fluids 

Type of Drilling Fluid Estimated Volume of Drilling Fluid to be Used per 

Well 

Water-based (seawater, freshwater, barite) 25000 

Oil-based (diesel, minerals, oil) 0 

Synthetic-based (internal olefin, ester) 8000 

 (e) New or Unusual Technology

Eni does not propose to use any new or unusual technology to carry out the proposed exploration activities. 

(f) Bonding Statement

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

bond, furnished and maintained according to 30 CFR 256, subpart I; NTL No. 2000-G16, "Guidelines for General 

Lease Surety Bonds;" and additional security under 30 CFR 256.53(d) and National NTL No. 2008-N07, 

“Supplemental Bond Procedures.” 

(g) Oil Spill Financial Responsibility

Oil Spill Financial Responsibility coverage will be obtained under Eni US Operating Co. Inc., BOEMRE company 

number 02782 for the activities proposed under this Exploration Plan according to 30 CFR Part 253; and NTL No. 

2008-N05, "Guidelines for Oil Spill Financial Responsibility for Covered Facilities". 

(h) Deepwater Well Control Statement

Eni Us Operating Co. Inc., BOEMRE company number 02782, has the financial capability to drill a relief well and 

conduct other emergency well control operations. 

(j) Blowout Scenario

Should a blow-out occur, the formation types in this area do not tend to bridge over of their own accord. Eni will use 

sub-surface BOPs with accumulator bottles attached to the BOP skid package. Sufficient accumulator bottles to 

activate the BOPs are located on the BOP skid package. The control lines are fed from rig to the sub-surface control 

system which activates the BOP. Two activation systems exist to allow rig floor activation or remote activation of 

the BOPs. 

If the subsea BOP and wellhead remain intact but do not close upon activation from the rig, ROVs located either on 

the rig or a stand-by boat shall be launched to attempt to close the BOPs by pumping into the secondary intervention 

devices located on the BOP within twelve (12) hours, unless the area is deemed unsafe. Once the area is deemed 

safe to enter, ships will launch ROVs to perform the intervention actions. 

The present calculated release from the wellbore is 5,194 Bbls of oil per day and 1.2 MM cubic feet of gas per day. 

If a relief well to kill the original well was required; it would be expected to take 80 days. 

An approximate breakdown of this time with only DP rigs would include: 

Time of obtain rig, rig to temporarily abandon well they are presently on, and move to location of blow-out: 10 

days 

Drill to depth 50 days 

Drill to intersect point 10 days 
Eni US Operating Co. Inc. Page 3

Revised Exploration Plan (Control No. R-5089) DECEMBER 1, 2010 

Walker Ridge 675 & 719 (OCS-G 32700 & 32704)

Drill Intersection 7 days 

Kill with downhole kill procedure 3 days 

Therefore a total release if the well did not bridge over would be 415,520 barrels of oil and 96 MM cubic feet of gas. 

There are no structures in the area near this location. Therefore, no platform could be used of relief well operations. 

Eni would use only Dynamically Positioned (DP) rigs for the relief well operations. Eni would use two (2) to 

possibly three (3) rigs to ensure the blow-out well could be brought under control even if one relief well encountered 

problems while drilling. 

Eni follows the BOEMRE schedule for BOP tests and expects and demands that BOPs are kept functional by the 

contractors. Eni will shut down operations for any repairs needed on well control devices anytime they are not 

considered functional and safe. Eni uses Company representatives with many years of experience for drilling 

operations and they constantly communicate with the OIM on the rig to ensure the safety of all personnel and 

equipment. All Company representatives maintain Well Control Certificates and are trained in well control. 

Eni uses multiple liners to cover potential production zones to reduce the risk of loss of well integrity. 

Eni foresees no restrictions for DP rigs to work in the area to perform well intervention and control. Eni would 

review and hire DP rigs to prevent usage of mooring systems therefore saving time to bring the well under control. 

Since the original well bore would be considered un-usable; Eni would drill from some distance to prevent either oil 

or gas from the damaged well, from affected the intervention activities. Flammable meters on the intervention rigs 

would be supplemented with additional detectors on the rig to ensure protection of personnel and equipment. If 

detectors registered high levels of LELs, the rigs would be shut down during that time to protect personnel and the 

equipment. 

Eni maintains additional materials on board the rig in order to “weight-up” the mud system to control any upsets or 

well control issues. Mud pits are monitored constantly by personnel when operations are ongoing. In addition, 

automatic alarms are located in the pits and will sound if pits receive abnormal amounts of return fluids to alert of 

possible flow control problems. Personnel on the rig floor are trained to monitor the systems and respond 

immediately if a problem is noted or if alarms sound and will take all necessary steps including operating the BOPs 

to maintain control of the well. 
Eni US Operating Co. Inc. Page 4

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SECTION C 

GEOLOGICAL AND GEOPHYSICAL INFORMATION 

The information for this section has not changed and was discussed under an approved Initial Exploration Plan, 

Control No. N-9509, pages 4 and 5 under Geological and Geophysical Information. 
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SECTION D 

HYDROGEN SULFIDE INFORMATION 

The information for this section has not changed and was discussed under an approved Initial Exploration Plan, 

Control No. N-9509, page 6, Hydrogen Sulfide Information. 
Eni US Operating Co. Inc. Page 6 

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SECTION E 

BIOLOGICAL, PHYSICAL AND SOCIOECONOMIC INFORMATION

The information for this section has not changed and was discussed under an approved Initial Exploration Plan, 

Control No. N-9509, pages 8 and 9, Biological, Physical and Socioeconomic Information. 
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SECTION F 

WASTES AND DISCHARGES INFORMATION 

Projected Generated Wastes and Projected Ocean Discharges

TABLE 1. 

WASTES YOU WILL GENERATE, TREAT AND DOWNHOLE DISPOSE OR DISCHARGE TO 

THE GOM 

All discharges associated with operations proposed in this Exploration Plan will be in accordance with

regulations implemented by the Bureau of Ocean Energy Management, Regulation & Enforcement 

(BOEMRE), U. S. Coast Guard (USCG) and the U.S. Environmental Protection Agency (EPA). 
please specify if the amount reported is a total or per well amount

Projected generated waste Projected ocean discharges 

Type of Waste Composition Projected Amount Discharge rate Discharge Meth

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

EXAMPLE: Cuttings wetted with synthetic based fluid 

Cuttings generated while using synthetic based drilling X bbl/well X bbl/day/well discharge overb

Water-based drilling fluid barite, additives 45,000 1,000 discharge over

Cuttings wetted with water-based fluid Cuttings generated while using water based drilling fluid. 5,000 500 discharge overbCuttings wetted with synthetic-based fluid 

cuttings generated whle using synthetic based drilling fluid 7,000 200 discharge overb

Brine brine 21,000 <1,000 discharge overb

Will humans be there? If yes, expect conventional waste

EXAMPLE: Sanitary waste water

Sanitary waste from living quarters X bbl/well X bbl/hr/well

chlorinate and doverboard 

Domestic waste soap, rinse water 2,000,000 gallons 3,500 gal/day discharged over

Sanitary waste Sanitary waste from living quarters 1.4 million gallons < 2,500 gal/day discharged over

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

Deck Drainage rainwater. Washdown water 30,000 barrels 100 bbl/hr overboard disch

Will you conduct well treatment, completion, or workover? 

Well treatment fluids N/A

Well completion fluids 8000 bbl < 100 bbl/hour Treat and dischaWorkover fluids N/A

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

Desalinization unit discharge Seawater 200 bbl/day 200 bbl/day discharged to se

Blowout prevent fluid Environmental safe fluid 10 bbl 10 bbl/well discharged to seBallast water Seawater 3,000 bbl 3,000 bbl discharged to seBilge water N/AExcess cement at seafloor Cement, additives 800 barrels 800 barrels/well discharged at seFire water Seawater 20,000 bbl/well <100 bbl/hr discharged at seCooling water Seawater - non-contact

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

Produced water N/A

Will you be covered by an individual or general NPDES permit ? GENERALNOTE: If you will not have a type of waste, enter NA in the row. 

TABLE 1. WASTES YOU WILL GENERATE, TREAT AND DOWNHOLE DISPOSE OR DISCHTO THE GOM
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SECTION G 

AIR EMISSIONS INFORMATION 

The Air Quality Report was revised for the year 2011 since the exploration activities were moved for Well Location 

“A”, please see attached sheets. 

All other information on the Air Quality Report will remain the same as approved under Control No. N-9509, page 

11, Air Quality Report and no other impacts or changes will be made for Locations “B” to “G”; the emissions for 

these locations will remain the same as previously approved. 
Eni US Operating Co. Inc. Page 9 

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SECTION H 

OIL SPILLS INFORMATION 

(a) Oil Spill Response Planning 

(2)(i) All the proposed activities and facilities in this Exploration Plan will be covered by Eni’s Oil Spill

Response Plan filed by Eni US Operating Co. Inc. – Operator number 02782 in accordance with 30 CFR 

254 and approved on March 17, 2009 and most recently modified on October 25, 2010.

(a)(2)(ii) SPILL RESPONSE SITES

Primary Response Equipment Location Preplanned Staging Location(s) 

Clean Gulf Associates - Venice, Louisiana Clean Gulf Associates – Galveston, Ingleside, and 

Houston, Texas, Intracoastal City, Venice, Lake 

Charles, Leeville, Houma, and Fort Jackson, 

Louisiana 

(a)(2)(iii) OSRO INFORMATION

Eni’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. 

(a)(2)(iv) WORST-CASE SCENARIO COMPARISON 

Category Regional OSRP 

WCD 

EP 

WCD 

Type of Activity Exploratory Exploratory 

Facility Location (Area/Block) MC 546 Walker Ridge 675 & 719 

Facility Designation Semi-Submersible Locations A to G 

Distance to Nearest Shoreline 

(miles) 38 193 

Volume 

 Storage tanks (total) 

 Uncontrolled blowout 

Total Volume 

156,816 5,194 

Type of Oil(s) 

(crude, condensate, diesel) Oil Oil 

API Gravity 41.3 ° 32° 

Eni has determined that the worst-case scenario from the activities proposed in this EP do not supersede the worstcase scenario from our approved Regional OSRP.

Since Eni has the capability to respond to the worst-case spill scenario included in our Regional OSRP approved on 

March 17, 2009, and most recently modified on October 25, 2010, since the worst-case scenario determined for our 

EP does not replace the worst-case scenario in our Regional OSRP, I hereby certify that Eni 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. Eni’s Regional OSRP Certification was accepted 

December 29, 2010. 
Eni US Operating Co. Inc. Page 10 

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(b) Spill Response Discussion for NEPA Analysis

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 

5,194 barrels of crude oil with an API gravity of 32°. 

Land Segment and Resource Identification 

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

information in the BOEM Oil Spill Risk Analysis Model (OSRAM) for the Central and Western Gulf of 

Mexico available on the BOEM website. 

The results are shown in Figure 1. The BOEM OSRAM identifies a 2% probability of impact to the 

shorelines of Matagorda County, Texas and/or Cameron Parish, Louisiana within 30 days. Matagorda 

County stretches from Matagorda Bay, across the Colorado River and up to the border of San Bernard 

Wildlife Refuge (immediately west of the San Bernard River). The county includes Matagorda Peninsula 

on the Gulf coast and Matagorda Bay. This area is primarily open beach. However, marshland exists 

along the east side of Matagorda Bay. Several bird rookeries are present around the peninsula. Seagrass is 

present off of Matagorda Peninsula on the bay side. Cameron Parish includes the east side of Sabine 

Lake, Sabine National Wildlife Refuge, Calcasieu Lake, Lacassine National Wildlife Refuge (inland) and

Grand Lake. Cameron Parish also includes the area along the coastline from Sabine Pass to Big 

Constance Lake in Rockefeller Wildlife Refuge. This region is composed of open public beaches, 

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

several rare, threatened and endangered species. 

Response 

Eni US Operating Co. Inc. will make every effort to respond to the Worst Case Discharge as effectively

as practicable. A description of the response equipment available to contain and recover the Worst Case 

Discharge is shown in Figure 2. Using the estimated chemical and physical characteristics of crude oil, an 

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

36% or 1,869 barrels of crude oil would be evaporated/dispersed within 24 hours, with 3,325 barrels 

remaining. 

Spill Response WR 719 Barrels of Oil

WCD Volume 5,194

Less 36% natural evaporation/dispersion 1,869

Remaining volume 3,325

Oil addressed by aerial dispersants 7,540

Oil addressed by in-situ burning 166

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

equipment available to respond to a spill of 5,194 barrels. The list estimates individual times needed for 

procurement, load out, travel time to the site and deployment. Figure 2 also indicates how operations will 

be supported.
Eni US Operating Co. Inc. Page 11 

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If aerial dispersants are utilized, 8 sorties (9,600 gallons) from two of the DC-3 aircrafts and 4 sorties 

(8,000 gallons) from the Basler aircraft should disperse approximately 7,540 barrels of product. If the 

conditions are favorable for in-situ burning, the proper approvals have been obtained and the proper 

planning is in place, in-situ burning of oil may be attempted. Using estimates based on the Deepwater 

Horizon spill of 2010, up to 5% or 166 barrels of the total daily Worst Case Discharge volume could be

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

Offshore response strategies may include attempting to skim utilizing the HOSS Barge and three Fast 

Response Units (FRUs), with a total derated skimming capacity of 54,310 barrels. Temporary storage 

associated with skimming equipment equals 4,500 barrels. If additional storage is needed, a 47,000 barrel 

storage barge 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 Matagorda County, Texas and/or 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 over 30,000 feet of 18” 

shoreline protection boom. Figure 2 (below) 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. The One-Gulf Plan (Area Contingency Plan) and Unified Command would be consulted 

to ensure that environmental and special economic resources would be correctly identified and prioritized 

to ensure optimal protection. Shoreline protection strategies depict the protection response modes 

applicable for oil spill clean-up operations. Each response mode is schematically represented to show 

optimum deployment and operation of the equipment in areas of environmental concern. 

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

more effective response to site-specific circumstances. Eni US Operating Co. Inc.’s contract Spill 

Management Team holds a copy of the One-Gulf Plan and the State of Louisiana Initial Oil Spill 

Response Plan. 
Eni US Operating Co. Inc. Page 12 

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Initial Response Considerations 

Actual actions taken during an oil spill response will be based on many factors to include but not 

be limited to: 

• Weather 

• Equipment and materials availability 

• Ocean currents and tides 

• Location of the spill 

• Product spilled 

• Amount spilled 

• Environmental risk assessments 

• Trajectory and product analysis 

• Well status, i.e., shut in or continual release 

Eni US Operating Co. Inc. will take action to provide a safe, aggressive response to contain and recover 

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

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

possible as far from environmentally sensitive areas as possible. Safety will take precedence over all other 

considerations during these operations. 

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

• Information will be confirmed 

• An assessment will be made and initial objectives set 

• OSROs and appropriate agencies will be notified 

• ICS 201, Initial Report Form completed 

• Initial Safety plan will be written and published

• Unified Command will be established 

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

objectives 

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

o On-site command and control established 

Offshore Response Actions

Equipment Deployment 

Surveillance 

• Surveillance Aircraft: within two hours of QI notification, or at first light 

• Provide trained observer to provide on site status reports 

• Provide command and control platform at the site if needed 

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

confirmation 

• Continual monitoring of vessel assets using vessel monitoring systems 

Dispersant application assets 

• Put ASI on standby 

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

• Gain FOSC approval for use of dispersants on the surface 

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

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

• Confirm dispersant availability for current and long range operations 

• Start ordering dispersant stocks required for expected operations 
Eni US Operating Co. Inc. Page 13 

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Containment boom 

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

• Ensure boom handling and mooring equipment is deployed with boom 

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

most effective containment 

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

Dedicated off-shore skimming systems 

General 

• Deployed to the highest concentration of oil 

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

CGA HOSS Barge 

• Use in areas with heaviest oil concentrations 

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

CGA FRUs 

• To the area of the thickest oil 

• Use as far off-shore as allowed 

Storage Vessels 

• Establish availability of CGA contracted assets 

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

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

systems 

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

Vessels of Opportunity (VOO) 

• Use Eni US Operating Co. Inc.’s contracted resources as applicable 

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

(VOSS) 

• Acquire additional resources as needed 

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

• Expect mission specific and safety training to be required 

• Plan with the US Coast Guard for vessel inspections 

In-situ Burn assets 

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

SOSC 

• Determine availability of fire boom and selected ignition systems 

• Start ordering fire boom stocks required for expected operations 

• Contact boom manufacturer to provide training if required 

• Determine assets to perform on water operation 

• Build operations into safety plan 

• Conduct operations in accordance with an approved plan 

Near Shore Response Actions 

Timing 

• Put near shore assets on standby and deployment in accordance with planning based on the actual 

situation, actual trajectories and oil budgets 

• VOO identification and training in advance of spill nearing shoreline if possible 
Eni US Operating Co. Inc. Page 14 

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• Outfitting of VOOs for specific missions 

• Deployment of assets based on actual movement of oil

Considerations 

• Water depth, vessel draft 

• Shoreline gradient 

• State of the oil 

• Use of VOOs 

• Distance of surf zone from shoreline 

Equipment Deployment 

Surveillance 

• Provide trained observer to direct skimming operations 

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

confirmation 

• Continual monitoring of vessel assets 

Dispersant Use 

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

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

Vessel Deployment 

Dedicated Near Shore skimming systems 

• FRVs 

• Egmopol and Marco SWS 

• Operate with aerial spotter directing systems to observed oil slicks 

VOO 

• Use Eni US Operating Co. Inc.’s contracted resources as applicable 

• Industry vessel are usually best for deployment of Vessel of Opportunity Skimming Systems 

(VOSS) 

• Acquire additional resources as needed 

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

• Expect mission specific and safety training to be required 

• Plan with the US Coast Guard for vessel inspections 

• Operate with aerial spotter directing systems to oil patches 

Shoreline Protection Operations 

Response Planning Considerations 

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

• Time to acquire personnel and equipment and their availability 

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

currently (Feb 2011) for Louisiana, The State of Louisiana Initial Oil Spill Response Plan, 

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

Actions 

Placement of boom 

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

ACP 
Eni US Operating Co. Inc. Page 15 

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

Consider: 

o Trajectories 

o Weather forecast 

o Oil Impact forecast 

o Verified spill movement 

o Boom, manpower and vessel (shallow draft) availability 

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

Beach Preparation 

Considerations and Actions 

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

• Shoreline Cleanup and Assessment Team Reports and recommendations 

• Determination of Archeological sites and gaining authority to enter 

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

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

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

maximize on-site work time 

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

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

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

• Passive clean up of marshes should considered and appropriate stocks of sorbent boom and/or 

sweep obtained 

• Earthen berms and shoreline protection boom may be considered to protect sensitive inland areas 

Decanting Strategy 

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

state. When separation occurs, the relatively clean water phase can be siphoned or decanted back to the 

recovery point with minimal, if any, impact. Decanting therefore increases the effective on-site oil storage 

capacity and equipment operating time. FOSC/SOSC approval will be requested prior to decanting 

operations. This practice is routinely used for oil spill recovery. 

CGA Equipment Limitations 

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

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

placed on. Most importantly, however, the decision to operate will be based on the judgment of the 

Unified Command and/or the Captain of the vessel, who will ultimately have the final say in terminating 

operations. Skimming equipment listed below may have operational limits which exceed those safety 

thresholds. As was seen in the Deepwater Horizon (DWH) oil spill response, vessel skimming operations 

ceased when seas reached 5-6 feet and vessels were often recalled to port when those conditions were 

exceeded. Systems below are some of the most up-to-date systems available and were employed during 

the DWH spill. 
Eni US Operating Co. Inc. Page 16 

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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 OSRV 4 foot seas 

Environmental Conditions in the GOM 

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

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

currents, and waves refracting shoreward produce the prevailing westerly longshore currents. Tides are

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

duration of the wind has a considerable effect on the tides and currents. Fifteen foot tides may be 

expected during severe hurricanes and very low tides may accompany strong northerlies of long duration. 

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

late summer. During the winter the average is slightly less than 60° F and the range is between 35 and 80° 

F. 

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

winds during the winter and easterly winds in the summer. Average wind speed is generally 14-15 mph 

along the coast. Wave heights average 4 and 5 feet. However, during hurricane season, Louisiana has 

recorded wave heights ranging from 40 to 50 feet high and winds reaching speeds of 100 mph. Because 

much of southern Louisiana lies below sea level, flooding is prominent. Surface water temperature ranges 

between 70 and 80°F during the summer months. During the winter, the average temperature will range 

from 50 and 60°F. 

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

tropical activity occurs within this window. The Atlantic basin shows a very peaked season from August

through October, with 78% of the tropical storm days, 87% of the minor (Saffir-Simpson Scale categories 

1 and 2) hurricane days, and 96% of the major (Saffir-Simpson categories 3, 4 and 5) hurricane days 

occurring then. Maximum activity is in early to mid September. Once in a few years there may be a 

hurricane occurring "out of season" - primarily in May or December. Globally, September is the most 

active month and May is the least active month. 
Eni US Operating Co. Inc. Page 17 

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SECTION I 

ENVIRONMENTAL MONITORING INFORMATION 

The information for this section was discussed under an approved Initial Exploration Plan, Control No. N-9509, 

page 14, Environmental Monitoring Information and will remain the same, no changes or impacts. 
Eni US Operating Co. Inc. Page 23

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SECTION J 

LEASE STIPULATIONS INFORMATION 

The information for this section was discussed under an approved Initial Exploration Plan, Control No. N-9509, 

page 15, Lease Stipulation Information and will remain the same, no changes. 
Eni US Operating Co. Inc. Page 24

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SECTION K 

ENVIRONMENTAL MITIGATION MEASURES INFORMATION 

 (a) Mitigation Measures Taken to Minimize Impact to Marine and Coastal Environment

Eni does not propose to use any measures beyond those required by the regulations in this part to 

minimize or mitigate environmental impacts from our proposed activities. 

(b) Incidental Takes

Eni US Operating Co. Inc. 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” 
Eni US Operating Co. Inc. Page 25 

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APPENDIX L 

SUPPORT VESSELS AND AIRCRAFT INFORMATION 

General 

The information for this section was discussed under an approved Initial Exploration Plan, Control No. N-9509, page 

18 and will remain the same, no changes. 

Diesel Oil Supply Vessels 

Size of Fuel Supply 

Vessel 

Capacity of Fuel 

Supply Vessel 

Frequency of Fuel 

Transfers 

Route Fuel Supply 

Vessel Will Take 

210 feet 202,280 gals Weekly From the Shorebase in 

Fourchon, LA, to the rig at 

WR619/675 

Drilling Fluid/ Solid and Liquid Waste Transportation

TABLE 2: 

WASTES YOU WILL TRANSPORT AND /OR DISPOSE OF ONSHORE

Vicinity Map

A vicinity map was submitted and approved under an Initial Exploration Plan, Control No. N-9509, page 18; no 

changes. 
please specify whether the amount reported is a total or per well

Projected 

generated waste

Solid and Liquid Wastes 

transportation 

Type of Waste Composition Transport Method

Name/Location of Facility Amount 

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

EXAMPLE: Synthetic-based drilling fluid or mud internal olefin, ester

Below deck storage tanks on offshore support vessels

Newport Environmental Services Inc., Ingleside, TX X bbl/we

Oil-based drilling fluid or mud N/A

Synthetic-based drilling fluid or mud olefin, ester Below deck storage tanks on offshore support vessel Newpark Environmental, Fourcho

s 10,000 b

Cuttings wetted with Water-based fluid N/ACuttings wetted with Synthetic-based fluid N/ACuttings wetted with oil-based fluids N/A

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

Produced sand N/A

EXAMPLE: trash and debris (recylables) Plastic, paper, aluminum barged in a storage bin ARC, New Iberia, LA X lb/welTrash and debris (recyclable materials) Plastic, paper, aluminum

Placed in green bags, taken to shore 

and placed in 30 yd roll-off contaners for recyling ARC, New Iberia, LA 20 cubic 

Used oil Oil, Engine components Tote tanks L&L 6,000 gaWash water Oil contaminated Tote tanks L&L 500 gall

Chemical product wastes solvents, cleaning fluids, wax Tote tanks L&L 3,000 ga

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

Waste D

TABLE 2. WASTES YOU WILL TRANSPORT AND /OR DISPOSE OF ONSHORE 

Will you have additional wastes that are not permitted for discharge? If yes, fill in the appropriate rows. 
Eni US Operating Co. Inc. Page 26

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SECTION M 

ONSHORE SUPPORT FACILITIES INFORMATION 

The information for this section was discussed under an approved Initial Exploration Plan, Control No. N-9509, 

page 19 under Onshore Support Facilities Information and will remain the same, no changes. 
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Walker Ridge 675 & 719 (OCS-G 32700 & 32704)

SECTION 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. 

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Revised Exploration Plan (Control No. R-5089) DECEMBER 1, 2010 

Walker Ridge 675 & 719 (OCS-G 32700 & 32704)

SECTION O 

ENVIRONMENTAL IMPACT ANALYSIS (EIA) 

In accordance with the requirements of 30 CFR 250.227 and 250.261 an Environmental Impact Analysis (EIA) was 

submitted and approved under an Initial Exploration Plan, Control No. N-9509. No additional changes to this 

section. 
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SECTION P 

ADMINISTRATIVE INFORMATION 

(a) Exempted Information Description

The proposed bottom-hole locations of the planned well 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

Initial Exploration Plan, Control No. N-9509, Approved May 2010.