UNITED STATES GOVERNMENT MEMORANDUM

To: Public Information (MS 5030)

Plans Section, Office of Field 

Operations (MS 5231)

Public Information copy of DOCD

Control # - S-07679

Type - Supplemental Development Operations Coordinations Document

Lease(s) - OCS-G08010 Block - 298 Green Canyon Area

Operator - Eni US Operating Co. Inc.

Drill & Complete Well No. SS007

Drillship, 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.

Tonya Jez

Plan Coordinator

G08010/GC/298

G08010/GC/298

1776 FSL, 2469 FWL

1776 FSL, 2469 FWL

G08010/GC/298

G08010/GC/298

WELL/007

WELL/SS007

Site Type/Name Botm Lse/Area/Blk Surface Location Surf Lse/Area/Blk

Description -

Rig Type -

Subject:

From:

January 8, 2015


SUPPLEMENTAL 

 DEVELOPMENT OPERATIONS 

COORDINATION DOCUMENT 

GREEN CANYON BLOCK 298 

LEASE OCS-G 08010 

PUBLIC INFORMATION COPY

Submitted by: 

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

SUPPLEMENTAL 

DEVELOPMENT OPERATIONS COORDINATON DOCUMENT 

LEASE OCS-G 08010 

GREEN CANYON BLOCK 298 

SECTION A Plan Contents 

SECTION B General Information 

SECTION C Geological, Geophysical Information 

SECTION D H2S Information 

 

SECTION E Mineral Resources Conservation Information 

SECTION F Biological, Physical and Socioeconomic Information 

SECTION G Wastes and Discharge Information 

SECTION H Air Emissions Information 

SECTION I Oil Spill Information 

SECTION J Environmental Monitoring Information 

SECTION K Lease Stipulations Information 

SECTION L Environmental Mitigation Measures Information 

SECTION M Related Facilities and Operations Information 

SECTION N Support Vessels and Aircraft Information 

SECTION O Onshore Support Facilities Information 

SECTION P Coastal Zone Management Act (CZMA) Information 

SECTION Q Environmental Impact Analysis 

SECTION R Administrative Information 
Eni US Operating Co. Inc. Page 1 

Supplemental DOCD May 19, 2014 

Green Canyon Block 298 (OCS-G 08010) Public Information

SECTION A 

PLAN CONTENTS 

(a) Plan Information Form 

This Supplemental Development Operations Coordination Document (S-DOCD) provides for the drilling, 

completion, installation of lease term pipelines, jumpers, associated umbilical’s, and commencement of 

production from Lease OCS-G 08010, Well No. 007 (to be renamed SS007). 

Eni is planning to further develop the Allegheny Field located in the Green Canyon Block 254 by adding 

production from an additional well (Well No. 007 {to be renamed SS007}) in Green Canyon Block 

298.Well No. 007, to be renamed SS007, is expected to spud on or about November 15,2014. 

Eni recently drilled, completed and is currently producing Lease OCS-G 08010, Green Canyon Block 

298, SS006 (ST01BP01) as of September 16, 2012. Other wells located in the vicinity and are currently 

producing consist of Lease OCS-G 08010, Well No.’s 001 (ST03BP01), SS005 (ST00BP05), 004 

(ST04BP01). 

See attached OCS Plan Information Form – Form BOEM-137, included under this section showing the 

activity schedule. 

(b) Location 

A Well Location Map showing the proposed surface and bottom-hole location of the proposed well is 

included in this plan along with a Bathymetry Map showing the water depths across the lease block. 

The pipeline, jumpers and associated umbilical will be installed using a dynamically positioned 

installation vessel; therefore no anchors will be associated with these development activities.

(c) Safety and Pollution Prevention Features

Eni will use a dynamically positioned rig or similar with subsea BOP’s, and will comply with all of the 

regulations of the ABS, IMO and USCG. All drilling operations will be conducted under the provisions of 

30 CFR, Part 250, Subpart D, and other applicable regulations and notice to lessees, including those 

regarding the avoidance of potential drilling hazards and safety and pollution prevention control. Such 

measures as inflow detection and well control, monitoring for loss of circulation and seepage loss, and 

casing design will be our primary safety measures. 

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

areas to collect all contaminants and debris. All discharges will be in accordance with applicable EPA 

NPDES permits. 

(d) Storage Tanks and/or Production Vessels 

Type of 

Storage Tank 

Type of 

Facility 

Tank Capacity 

(bbls) 

Number 

of Tanks 

Total 

Capacity 

(bbls) 

Fluid Gravity 

(API) 

Fuel Oil (Marine 

Diesel) DP Drillship 901 4 3604 0.35 

Fuel Oil (Marine 

Diesel) DP Drillship 19,386.8 2 38,773.6 0.35 

Fuel Oil (Marine 

Diesel) DP Drillship 988 2 1976 0.35 
Eni US Operating Co. Inc. Page 2 

Supplemental DOCD May 19, 2014 

Green Canyon Block 298 (OCS-G 08010) Public Information

Type of 

Storage Tank 

Type of 

Facility 

Tank Capacity 

(bbls) 

Number 

of Tanks

Total 

Capacity 

(bbls) 

Fluid 

Gravity 

(API)

Fuel Oil (Marine 

Diesel) DP Drillship 4,400 1 4,400 0.35 

Fuel Oil (Marine 

Diesel) DP Drillship 1.26 4 5.04 0.35 

Fuel Oil (Marine 

Diesel) DP Drillship 1.58 1 1.58 0.35 

Fuel Oil (Marine 

Diesel) DP Drillship 4.76 1 4.76 0.35 

Fuel Oil (Marine 

Diesel) DP Drillship 225 2 450 0.35 

Liquid Mud DP Drillship 51.3 1 51.3 -- 

Drill Water DP Drillship 559 1 559 -- 

Potable Water DP Drillship 199.6 1 199.6 -- 

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 16,700 1 16,700 36° 

Active Mud Pits DP Semi 4,500 1 4,500 NA 

Reserve Liquid Mud 

Storage DP Semi 11,750 1 11,750 NA 

Drill Water DP Semi 14,000 1 14,000 NA 

Potable Water DP Semi 1,570 1 1,570 NA 

(e) Processing Fee 

A Pay.gov receipt is being included in this plan in the amount of $4,238.00 to cover the cost and 

processing fee for the proposed operations being conducted under this plan 

(f) Pollution Prevention Measures 

Pursuant to NTL 2008-G04 the proposed operations covered by this DOCD do not require Eni to 

specifically address the discharges of oils and greases from the rig during rainfall or routine operations. 

Nevertheless, Eni has provided this information as part of its response to (c) above. 

(g) Additional Measures 

Health, safety, and environment are the primary topics in pre-tour and pre-job safety meetings. The 

discussion around no harm to people or environment is a key mindset. All personnel are reminded daily to 

inspect work areas for safety issues as well as potential pollution issues.

 
U.S. Department of the Interior OMB Control Number: 1010-0151 

Bureau of Ocean Energy Management OMB Approval Expires: 12/31/2014 

 

OCS PLAN INFORMATION FORM 

Form BOEM- 0137 (December 2011-Supersedes all previous editions of this form which may not be used) 

2

7

GENERAL INFORMATION 

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

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

Address: 1200 Smith Street, Suite 1700 Contact Person: Brenda Montalvo 

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

If a service fee is required under 30 CFR 550.125(a) provide the Amount paid $4,238.00 Receipt No. 24FQ46KL 

Project and Worst Case Discharge (WCD) Information

Lease: G08010 Area: GC Block: 298 Project Name (If Applicable): Allegheny South 

Objective(s): Oil Gas Sulphur Salt Onshore Support Base(s): Fourchon, LA 

Platform/Well Name: 007 (SS007) Total Volume of WCD: 147,099 BOPD API Gravity: 43° 

Distance to Closest Land (Miles): 94 Volume from uncontrolled blowout: 14.7 BOPD 

Have you previously provided information to verify the calculations and assumptions for your WCD? Yes X No 

If so, provide the Control number of the EP or DOCD with which this information was provided 

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

Do you propose to use a vessel with anchors to install or modify a structure? Yes X No 

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

Description of Proposed Activities Scheduled (Mark all that apply) 

Proposed Activity Start Date End Date No. of Days 

Development drilling 02/01/2015 03/02/2015 30 

Well completion 03/03/2015 04/01/2015 30 

Installation of subsea wellheads and/or manifolds 04/02/2015 04/03/2015 2 

Installation of lease term pipeline and umbilical 04/04/2015 04/05/2015 9 

Commence production 04/10/2015 

 

Description of Drilling Rig Description of Structure 

Jackup X Drillship Caisson X Tension leg platform 

Gorilla Jackup Platform rig Fixed platform Compliant tower 

Semisubmersible Submersible Spar Guyed Tower 

X DP Semisubmersible Other (Attach Description) Floating Production 

System Other (Attach Description) 

Drilling Rig Name (If Known): 

Description of Lease Term Pipelines 

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

Well No. 007 GC298 Existing South REM GC298 (lease pipeline) 6 12330 

Platform A (Allegheny) GC254 Well No. 007, GC298 (umbilical) 4 17154 

 
U.S. Department of the Interior OMB Control Number: 1010-0151 

Bureau of Ocean Energy Management OMB Approval Expires: 12/31/2014 

 

OCS PLAN INFORMATION FORM 

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

Form BOEM- 0137 (December 2011-Supersedes all previous editions of this form which may not be used) 

2

7

Proposed Well/Structure Location 

Well or Structure Name/Number (If renaming well or 

structure, reference previous name): Well No. 007 to be 

renamed SS007 

Previously reviewed under an 

approved EP or DOCD? 

 YES X NO 

Is this an existing well 

or structure? 

 

YES X NO 

If this is an existing well or 

structure, list the Complex ID or 

API No. 

Do you plan to use a subsea BOP or surface BOP on a floating facility to conduct your 

proposed activities? X YES NO 

WCD info 

For wells, volume of uncontrolled 

blowout (Bbls/day): 14.7 BOPD

For structures, volume of all 

storage and pipelines (Bbls): 

API Gravity of fluid: 43 

Surface Location Bottom-Hole Location (For 

Wells) 

Completion (For multiple completions, enter 

separate lines) 

Lease No. OCS-G 08010 

Area Name Green Canyon 

Block No. 298 

Blockline 

Departures 

(in feet) 

1,776’ FSL 

2,469’ FWL 

Lambert X-Y 

Coordinates 

X: 2,521,029’ 

Y: 10,044,336’ 

Latitude/ 

Longitude 

Latitude 27 ̊ 39’ 09.71” N 

Longitude 90 ̊ 16’ 45.87” W 

Water Depth (Feet): 3,400’

Anchor Radius (if applicable) in feet: 

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 or Seafloor 

 

 

 


Eni US Operating Co. Inc. Page 3

Supplemental DOCD May 19, 2014 

Green Canyon Block 298 (OCS-G 08010) Public Information

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 BSEE District. 

(b) Drilling Fluids 

Drilling fluids to be used for this well are described in Table 1 under Section F of this plan. 

(c) Production 

Proprietary Information 

(d) Oil Characteristics 

Proprietary Information 

(e) New or Unusual Technology 

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

activities. 

(f) Bonding Statement 

The bond requirements for the activities and facilities proposed in this DOCD 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 

In accordance with 30 CFR 253; and NTL 2008-N05, “Guidelines for Oil Spill Financial Responsibility 

for Covered Facilities”, Eni US Operating Co. Inc., BOEM company number 02782, maintains coverage

for the activities proposed under this DOCD. 

(h) Deepwater Well Control Statement 

Eni US Operating Co. Inc., BOEM company number 02782, has the financial capability to drill a relief 

well and conduct other emergency well control operations 

(i) Suspensions of Production 

Lease OCS-G 08010 is held by Unit Agreement No. 754395015 approved, effective 6/1/95. The unit 

agreement consists of OCS-G07049, G08010 and G08876. 

(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 the 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. Remote Operated Vehicle (ROV) activation is 

also built into the BOPs. In addition, a “deadman” switch exists in case of a rig “drift off” or loss of rig 

positioning. This system will activate the BOP and release the LMRP allowing the rig to float free to 

protect the well and well control systems 
Eni US Operating Co. Inc. Page 4

Supplemental DOCD May 19, 2014 

Green Canyon Block 298 (OCS-G 08010) Public Information

If the 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. 

If the ROV intervention is successful, Eni would return the rig, if undamaged, to the location and begin 

re-attachment and procedures to control the well once the BOPs are opened. 

The present calculated release from the wellbore is 147,099 Bbls of oil per day and 1137 MM cubic feet 

of gas per day. If a relief well to kill the original well was required; it would be expected to take 100 days 

to complete kill of the original well. 

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

Time of obtain rig, rig to temporarily abandon well they are presently on, and move to location of blowout: 10 days 

Drill to depth 60 days 

Drill to intersect point 20 days 

Drill Intersection 7 days 

Kill with downhole kill procedure 3 days 

Flow Rate per Day Duration of Blowout Total Volumes 

Oil – 147,099 BOPD 100 Days 14,709,900 BBL 

Gas – 1137 MMCF per day 100 Days 113,700 MMCF 

Therefore a total release if the well did not bridge over would be 14.7 million barrels of oil and 113.7 Bcf 

of gas. The closest structure to the location is the Eni US Operating Co. Inc. Allegheny MTLP 

approximately 5 miles from well center. Use of the MTLP to drill a relief well would not be feasible due 

to distance from the well to the TLP. 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 BSEE 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 in drilling operations. The Company Representatives constantly communicate with the OIM 

on the rig to ensure the safety of all personnel and equipment. All Company representatives are trained in 

well control and maintain Well Control Certificates. 

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 for relief well operations to prevent usage of mooring systems therefore 

saving time to bring the well under control. If the original well bore is considered un-usable; Eni would 

drill from some distance to prevent either oil or gas from the damaged well from affecting 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 US Operating Co. Inc. Page 5

Supplemental DOCD May 19, 2014 

Green Canyon Block 298 (OCS-G 08010) Public Information

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 6 

Supplemental DOCD May 19, 2014 

Green Canyon Block 298 (OCS-G 08010) Public Information

SECTION C 

GEOLOGICAL AND GEOPHYSICAL INFORMATION 

(e) Shallow Hazards Report 

A survey was conducted over Green Canyon Block 298. Copies of the report are being submitted with 

this plan under separate cover. 

(f) Shallow Hazards Assessment

A shallow hazards assessment has been prepared for the proposed surface location, evaluating seafloor 

and subsurface geological and manmade features and conditions that may adversely affect drilling 

operations, and is included as with this plan. 

Attachments 

1) Site Clearance Letter 



Eni US Operating Co. Inc. Page 7

Supplemental DOCD May 19, 2014 

Green Canyon Block 298 (OCS-G 08010) Public Information

SECTION D 

HYDROGEN SULFIDE INFORMATION 

(a) Concentration 

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

(b) Classification 

In accordance with Title 30 CFR 250.490(c), Eni requests that Green Canyon Block 298 be classified by 

BOEM as H2S absent. 

(c) H2S Contingency Plan

Eni does not anticipate encountering H2S while conducting the proposed development activities; however 

in the event it is encountered, Eni will submit to the appropriate BSEE district office an H2S Contingency 

Plan prepared according to 30 CFR 250.490(f) before conducting the proposed exploration activities. 

(d) Modeling Report 

Not applicable 
Eni US Operating Co. Inc. Page 8

Supplemental DOCD May 19, 2014

Green Canyon Block 298 (OCS-G 08010) Public Information

SECTION E 

MINERAL RESOURCE CONSERVATION INFORMATION 

(a) Technology & Reservoir Engineering Practices and Procedures

The reservoir will be initially produced by natural energy (aquifer and rock compaction). We may 

consider gas lift in the late life if we need more energy to enhance recovery. 

(b) Technology and Recovery Practices and Procedures 

Detail Petrel and Eclipse model has been completed and these tools will be used to ensure maximum 

recovery from the reservoir. 

(c) Reservoir Development 

Proprietary Information 
Eni US Operating Co. Inc. Page 9

Supplemental DOCD May 19, 2014 

Green Canyon Block 298 (OCS-G 08010) Public Information

SECTION F 

BIOLOGICAL, PHYSICAL AND SOCIOECONOMIC INFORMATION 

(a) High-Density Deepwater Benthic Communities Information 

Activities proposed in this plan will disturb seafloor areas in water depths greater the 300 meters (984 

feet), therefore, a report as described in Attachment A of NTL No. 2009-G40 "Deepwater Benthic 

Communities" has been conducted 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 assessment enclosed in Section C of this DOCD address a radius of 2,000 ft around the proposed 

surface location. Eni proposed to drill the well with a dynamically positioned rig, therefore no anchors 

will be deployed, and surface impacts will be restricted to the seafloor in the immediate vicinity of the 

borehole. 

(b) Topographic Features Map 

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

zone”. 

(c) Topographic Features Statement 

All activities proposed under this DOCD 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 

Green Canyon Block 298 is not located within 61 meters (200 feet) of any live-bottom (pinnacle trend) 

features. 

(e) Live Bottoms (Low Relief) Map 

Green Canyon Block 298 is not located within 100 feet of any live-bottom (low-relief) features.

(f) Potentially Sensitive Biological Features 

Green Canyon Block 298 is not located within 30 meters (100 feet) of potentially sensitive biological 

features. 

(g) Remotely Operated Vehicle (ROV) Surveys 

Eni is familiar with the ROV Survey and reporting provisions of NTL 2008-G06. Green Canyon Block 

298 is located in Grid 13 in the Grid EA and ROV Status Report. The report indicates that Grid 13 has 

Adequate ROV survey coverage, therefore Eni is not required to submit a plan for an ROV monitoring 

survey per NTL 2008-G04. 

 

(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 the 30 CFR 550, Subpart B, and further outlined in Notice to Lessees (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. 
Eni US Operating Co. Inc. Page 10

Supplemental DOCD May 19, 2014 

Green Canyon Block 298 (OCS-G 08010) Public Information

NOAA Fisheries currently lists the Sperm Whale, Leatherback Turtle, Green Turtle, Hawksbill Turtle, 

and the Kemp’s Ridley Turtle as endangered and the Loggerhead Turtle and Gulf Sturgeon as 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 of 

our operations. 

(i) Archaeological Report 

The proposed drilling location lies within an area designated as archaeologically sensitive by BOEM as 

set forth in Notice to Lessees 2005-G07 and 2008-G05 (BOEM, 2005 and 2008). Tesla Offshore, LLC 

surveyed all of Block 298, with extended survey coverage into Blocks 253, 254, 297, 341, and 342, Green 

Canyon Area. The survey was conducted between August and October, 2005 along a 300 meter grid. The 

resulting archaeological assessment report was submitted to Eni under Tesla Job No. 05-353-11; this 

original assessment was prepared prior to the requirement for archaeological assessments in deepwater, 

therefore NTL-compliant, revised report was prepared and submitted to Eni under Tesla Job No. 14-021-

11. Eni contacted Tesla Offshore, LLC to provide this archaeological analysis (NTL No. 2005-G07) in 

accordance with the Bureau of Ocean Energy Management (BOEM) Gulf Of Mexico OCS Region. 

(j) Air and Water Quality Information 

Pursuant to NTL 2008-G04 the proposed operations covered by this DOCD do not require Eni to provide 

additional information relating to air and water quality information.

(k) Socioeconomic Information 

Pursuant to NTL 2008-G04 the proposed operations covered by this DOCD do not require Eni to provide 

additional information relating to socioeconomic. 
Eni US Operating Co. Inc. Page 11

Supplemental DOCD May 19, 2014 

Green Canyon Block 298 (OCS-G 08010) Public Information

SECTION G 

WASTES AND DISCHARGES INFORMATION 

Projected Generated Wastes and Projected Ocean 

TABLE 1. 

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

GOM 

(c) Modeling Report 

Not required by EPA under the OCS General Permit.
Eni US Operating Co. Inc. Page 12

Supplemental DOCD May 19, 2014 

Green Canyon Block 298 (OCS-G 08010) Public Information
Eni US Operating Co. Inc. Page 13

Supplemental DOCD May 19, 2014 

Green Canyon Block 298 (OCS-G 08010) Public Information

SECTION H 

AIR EMISSIONS INFORMATION 

(a) Emissions Worksheets and Screening Questions 

(2) Screening Questions 

Screen Procedures for DOCD’s Yes No 

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

proposed development 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 

Does or will the facility complex associated with your proposed development and 

production activities process production from eight or more wells? 

 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 in excess or criteria set for the under 

250.1105(a)(2) and (3)? 

 X 

Do you propose to burn produced hydrocarbon liquids? X 

Are your proposed development and production activities located within 25 miles (40 

kilometers) from shore? 

 X 

Are your proposed development and production activities located within 124 miles (200 

kilometers) of the Breton Wilderness Area? 

 X 

This information was calculated by: Brenda Montalvo 

 (713) 393-6259 

 brenda.montalvo@enipetroleum.com 
DOCD AIR QUALITY SCREENING CHECKLIST 

OMB Approval Expires: 12/31

COMPANY Eni US Operating Co. Inc.AREA Green CanyonBLOCK 298LEASE G08010PLATFORMWELL 007 (to be renamed SS007)COMPANY CONTACT Brenda MontalvoTELEPHONE NO. (713) 393-6259REMARKS

Drill, complete, and install lease term pipeline, jumpers, associated umbiliand commencement of production from Lease G 08010, Well No. 007 (to renamed SS007) using a DP Semi

LEASE TERM PIPELINE CONSTRUCTION INFORMATION:

YEAR NUMBER OF TOTAL NUMBER OF CONSTRUCTION DAYS

PIPELINES

20142015 2 920162017201820192020202120222023

FORM BOEM-0139 (October 2011- Supersedes all previous versions of form BOEM-0139 which may not be used). 
AIR EMISSIONS CUMPUTATION FACTORS

Fuel Usage Conversion Factors Natural Gas Turbines Natural Gas Engines Diesel Recip. Engine RE

SCF/hp-hr 9.524 SCF/hp-hr 7.143 GAL/hp-hr 0.0483 AP42 3

Equipment/Emission Factors units PM SOx NOx VOC CO RENG Turbines gms/hp-hr 0.00247 1.3 0.01 0.83 AP42 3.2-NG 2-cycle lean gms/hp-hr 0.00185 10.9 0.43 1.5 AP42 3NG 4-cycle lean gms/hp-hr 0.00185 11.8 0.72 1.6 AP42 3NG 4-cycle rich gms/hp-hr 0.00185 10 0.14 8.6 AP42 3

Diesel Recip. < 600 hp. gms/hp-hr 1 1.468 14 1.12 3.03 AP42 3

Diesel Recip. > 600 hp. gms/hp-hr 0.32 1.468 11 0.33 2.4 AP42 3Diesel Boiler lbs/bbl 0.084 2.42 0.84 0.008 0.21 AP42 1.3NG Heaters/Boilers/Burners lbs/mmscf 7.6 0.593 100 5.5 84 AP42 1.4-1, 1NG Flares lbs/mmscf 0.593 71.4 60.3 388.5 AP42 1Liquid Flaring lbs/bbl 0.42 6.83 2 0.01 0.21 AP42 1.3-Tank Vapors lbs/bbl 0.03 E&P FFugitives lbs/hr/comp. 0.0005 API SGlycol Dehydrator Vent lbs/mmscf 6.6 La. DGas Venting lbs/scf 0.0034

Sulphur Content Source Value Units

Fuel Gas 3.33 ppm

Diesel Fuel 0.4 % weight

Produced Gas( Flares) 3.33 ppm

Produced Oil (Liquid Flaring) 1 % weight

FORM BOEM-0139 (October 2011 - Supersedes all previous versions of form BOEM-0139 which may not be used). Page 2 
AIR EMISSIONS CALCULATIONS - FIRST YEAR

COMPANY AREA BLOCK LEASE PLATFORM WELL CONTACT PHONE REMARKS

Eni US Operating Co. Inc. Green Canyon 298 G08010 007 (to be renamed SS007) Brenda Montalvo (713) 393-6259

OPERATIONS EQUIPMENT RATING MAX. FUEL ACT. FUEL RUN TIME MAXIMUM POUNDS PER HOUR 

Diesel Engines HP GAL/HR GAL/D

Nat. Gas Engines HP SCF/HR SCF/D

Burners MMBTU/HR SCF/HR SCF/D HR/D DAYS PM SOx NOx VOC CO PM 

DRILLING PRIME MOVER>600hp diesel 37478 1810.1874 43444.50 24 60 26.42 121.18 908.06 27.24 198.12 19.02 DP Semi PRIME MOVER>600hp diesel 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

BURNER diesel 0 0 0 0.00 0.00 0.00 0.00 0.00 0.00 VESSELS>600hp diesel(crew) 2065 99.7395 2393.75 10 8 1.46 6.68 50.03 1.50 10.92 0.06 VESSELS>600hp diesel(supply) 2065 99.7395 2393.75 12 17 1.46 6.68 50.03 1.50 10.92 0.15 VESSELS>600hp diesel(tugs) 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

PIPELINE PIPELINE LAY BARGE diesel 8800 425.04 10200.96 24 9 6.20 28.45 213.22 6.40 46.52 0.67 

INSTALLATION SUPPORT VESSEL diesel 2065 99.7395 2393.75 24 9 1.46 6.68 50.03 1.50 10.92 0.16 

PIPELINE BURY BARGE diesel 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

SUPPORT VESSEL diesel 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

FACILITY DERRICK BARGE diesel 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 INSTALLATION MATERIAL TUG diesel 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

VESSELS>600hp diesel(crew) 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

VESSELS>600hp diesel(supply) 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

PRODUCTION RECIP.<600hp diesel - North Crane (1) 174 8.4042 201.70 24 365 0.38 0.56 5.37 0.43 1.16 1.68 

RECIP.<600hp diesel - South Crane (1) 174 8.4042 201.70 24 365 0.38 0.56 5.37 0.43 1.16 1.68 

RECIP.<600hp diesel - Firewater Pump #1 375 18.1125 434.70 24 365 0.83 1.21 11.56 0.93 2.50 3.62 

RECIP.<600hp diesel - Firewater Pump #2 (1) 375 18.1125 434.70 24 365 0.83 1.21 11.56 0.93 2.50 3.62 RECIP.<600hp diesel - Auxiliary Generator (1) 536 25.8888 621.33 24 365 1.18 1.73 16.53 1.32 3.58 5.17 RECIP.<600hp diesel - Emergency Generator (1) 280 13.524 324.58 24 365 0.62 0.91 8.63 0.69 1.87 2.70 RECIP.<600hp diesel - Escape Capsule #1 (1) 36 1.7388 41.73 24 365 0.08 0.12 1.11 0.09 0.24 0.35 RECIP.<600hp diesel - Escape Capsule #2 (1) 36 1.7388 41.73 24 365 0.08 0.12 1.11 0.09 0.24 0.35 RECIP.<600hp diesel - Escape Capsule #3 (1) 36 1.7388 41.73 24 365 0.08 0.12 1.11 0.09 0.24 0.35 RECIP.<600hp diesel - Auxiliary Air Compressor (1) 75 3.6225 86.94 24 365 0.17 0.24 2.31 0.19 0.50 0.72 RECIP.>600hp diesel - Turbine Diesel Generator #1 (1) 6130 296.079 7105.90 24 365 4.32 19.82 148.52 4.46 32.41 18.92 RECIP.>600hp diesel - Turbine Diesel Generator #2 (1) 6130 296.079 7105.90 24 365 4.32 19.82 148.52 4.46 32.41 18.92 SUPPORT VESSEL diesel (1) 2400 115.92 2782.08 24 365 1.69 7.76 58.15 1.74 12.69 7.41 TURBINE nat gas - HPC Turbine Compressor (1) 10310 98192.44 2356618.56 24 365 7.27 0.06 29.52 0.23 18.85 31.83 TURBINE nat gas - Turbine Natural Gas Generator #1 (1) 6130 58382.12 1401170.88 24 365 4.32 0.03 17.55 0.14 11.21 18.92 TURBINE nat gas - Turbine Natural Gas Generator #2 (1) 6130 58382.12 1401170.88 24 365 4.32 0.03 17.55 0.14 11.21 18.92 

RECIP.4 cycle lean nat gas 0 0 0.00 0 0 0.00 0.00 0.00 0.00 

RECIP.4 cycle rich nat gas 0 0 0.00 0 0 0.00 0.00 0.00 0.00 

BURNER nat gas 0 0.00 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 MISC. BPD SCF/HR COUNTTANK- Dry Oil Storage Tank 10000 24 365 12.50 

TANK- Wet Oil Storage Tank 10000 24 365 0.00 0.00 12.50 0.00 

FLARE- 0 0 0 0.00 

PROCESS VENT- 0 0.00 FUGITIVES- 11500.0 365 5.75 

GLYCOL STILL VENT- 0 0 0 0.00 

DRILLING OIL BURN 0 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

WELL TEST GAS FLARE 0 0 0 0.00 0.00 0.00 0.00 

2015 YEAR TOTAL 67.85 223.98 1755.86 85.22 410.15 155.2

EXEMPTION 

CALCULATION DISTANCE FROM LAND IN MILES 3130.2

94.0

Drill, complete, and install leproduction from Lease G 08

FORM BOEM-0139 (October 2011- Supersedes all previous versions of form BOEM-0139 which may not be used). Page 3 
AIR EMISSIONS CALCULATIONS - SECOND YEAR

COMPANY AREA BLOCK LEASE PLATFORM WELL CONTACT PHONE REMARKS

Eni US Operating Co. Inc.Green Canyon 298 G08010 007 (to be renamed SS007) Brenda Montalvo (713) 393-6259

OPERATIONS EQUIPMENT RATING MAX. FUEL ACT. FUEL RUN TIME MAXIMUM POUNDS PER HOUR 

Diesel Engines HP GAL/HR GAL/D

Nat. Gas Engines HP SCF/HR SCF/D

Burners MMBTU/HR SCF/HR SCF/D HR/D DAYS PM SOx NOx VOC CO PM 

DRILLING PRIME MOVER>600hp diesel 0 0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

PRIME MOVER>600hp diesel 0 0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

PIPELINE PIPELINE LAY BARGE diesel 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

INSTALLATION SUPPORT VESSEL diesel 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

PIPELINE BURY BARGE diesel 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

FACILITY DERRICK BARGE diesel 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

INSTALLATION MATERIAL TUG diesel 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

VESSELS>600hp diesel(crew) 0 0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

VESSELS>600hp diesel(supply) 0 0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

PRODUCTION RECIP.<600hp diesel - North Crane (1) 174 8.4042 201.70 24 365 0.38 0.56 5.37 0.43 1.16 1.68 

RECIP.<600hp diesel - South Crane (1) 174 8.4042 201.70 24 365 0.38 0.56 5.37 0.43 1.16 1.68 

RECIP.<600hp diesel - Firewater Pump #1 375 18.1125 434.70 24 365 0.83 1.21 11.56 0.93 2.50 3.62 

RECIP.<600hp diesel - Firewater Pump #2 (1) 375 18.1125 434.70 24 365 0.83 1.21 11.56 0.93 2.50 3.62 RECIP.<600hp diesel - Auxiliary Generator (1) 536 25.8888 621.33 24 365 1.18 1.73 16.53 1.32 3.58 5.17 

RECIP.<600hp diesel - Emergency Generator (1) 280 13.524 324.58 24 365 0.62 0.91 8.63 0.69 1.87 2.70 

RECIP.<600hp diesel - Escape Capsule #1 (1) 36 1.7388 41.73 24 365 0.08 0.12 1.11 0.09 0.24 0.35 RECIP.<600hp diesel - Escape Capsule #2 (1) 36 1.7388 41.73 24 365 0.08 0.12 1.11 0.09 0.24 0.35 RECIP.<600hp diesel - Escape Capsule #3 (1) 36 1.7388 41.73 24 365 0.08 0.12 1.11 0.09 0.24 0.35 RECIP.<600hp diesel - Auxiliary Air Compressor (1) 75 3.6225 86.94 24 365 0.17 0.24 2.31 0.19 0.50 0.72 RECIP.>600hp diesel - Turbine Diesel Generator #1 (1) 6130 296.079 7105.90 24 365 4.32 19.82 148.52 4.46 32.41 18.92 RECIP.>600hp diesel - Turbine Diesel Generator #2 (1) 6130 296.079 7105.90 24 365 4.32 19.82 148.52 4.46 32.41 18.92 SUPPORT VESSEL diesel (1) 2400 115.92 2782.08 24 365 1.69 7.76 58.15 1.74 12.69 7.41 TURBINE nat gas - HPC Turbine Compressor (1) 10310 98192.44 2356618.56 24 365 7.27 0.06 29.52 0.23 18.85 31.83 TURBINE nat gas - Turbine Natural Gas Generator #1 (1) 6130 58382.12 1401170.88 24 365 4.32 0.03 17.55 0.14 11.21 18.92 TURBINE nat gas - Turbine Natural Gas Generator #2 (1) 6130 58382.12 1401170.88 24 365 4.32 0.03 17.55 0.14 11.21 18.92 

RECIP.4 cycle lean nat gas 0 0 0.00 0 0 0.00 0.00 0.00 0.00 

RECIP.4 cycle rich nat gas 0 0 0.00 0 0 0.00 0.00 0.00 0.00 

BURNER nat gas 0 0.00 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

MISC. BPD SCF/HR COUNTTANK- Dry Oil Storage Tank 10000 24 365 12.50 TANK- Wet Oil Storage Tank 10000 24 365 0.00 0.00 12.50 0.00 

FLARE- 0 0 0 0.00 

PROCESS VENT- 0 0 0

FUGITIVES- 11500.0 365 5.75 

GLYCOL STILL VENT- 0 0 0 0.00 

DRILLING OIL BURN 0 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

WELL TEST GAS FLARE 0 0 0 0.00 0.00 0.00 0.00 

2016 YEAR TOTAL 30.86 54.31 484.49 47.08 132.76 135.17 

EXEMPTION 

CALCULATION DISTANCE FROM LAND IN MILES 3130.20 

94.0

Drill, complete, and install leasof production from Lease G 08

FORM BOEM-0139 October 2011 - Supersedes all previous versions of form BOEM-0139 which may not be used). Page 4
AIR EMISSIONS CALCULATIONS

COMPANY AREA BLOCK LEASE PLATFORM WELL

Eni US Operating Co. Inc. Green Canyon 298 G08010 007 (t

Emitted Substance

Year

PM SOx NOx VOC 

2015 155.22 329.86 2811.41 201.69 

2016 135.17 237.86 2122.07 206.19 

Allowable 0.00 3130.20 3130.20 3130.20 

FORM BOEM-0139 (October 2011 - Supersedes all previous versions of form BOEM-0139 which may not be used). Page 
DOCD AIR QUALITY SCREENING CHECKLIST 

OMB Approval Expires: 12/31

COMPANY Eni US Operating Co. Inc.AREA Green CanyonBLOCK 298LEASE G08010PLATFORMWELL 007 (to be renamed SS007)COMPANY CONTACT Brenda MontalvoTELEPHONE NO. (713) 393-6259REMARKS

Drill, complete, and install lease term pipeline, jumpers, associated umbiliand commencement of production from Lease G 08010, Well No. 007 (to renamed SS007) using a Drillship

LEASE TERM PIPELINE CONSTRUCTION INFORMATION:

YEAR NUMBER OF TOTAL NUMBER OF CONSTRUCTION DAYS

PIPELINES

20142015 2 920162017201820192020202120222023

FORM BOEM-0139 (October 2011- Supersedes all previous versions of form BOEM-0139 which may not be used). 
AIR EMISSIONS CUMPUTATION FACTORS

Fuel Usage Conversion Factors Natural Gas Turbines Natural Gas Engines Diesel Recip. Engine RE

SCF/hp-hr 9.524 SCF/hp-hr 7.143 GAL/hp-hr 0.0483 AP42 3

Equipment/Emission Factors units PM SOx NOx VOC CO RENG Turbines gms/hp-hr 0.00247 1.3 0.01 0.83 AP42 3.2-NG 2-cycle lean gms/hp-hr 0.00185 10.9 0.43 1.5 AP42 3NG 4-cycle lean gms/hp-hr 0.00185 11.8 0.72 1.6 AP42 3NG 4-cycle rich gms/hp-hr 0.00185 10 0.14 8.6 AP42 3

Diesel Recip. < 600 hp. gms/hp-hr 1 1.468 14 1.12 3.03 AP42 3

Diesel Recip. > 600 hp. gms/hp-hr 0.32 1.468 11 0.33 2.4 AP42 3Diesel Boiler lbs/bbl 0.084 2.42 0.84 0.008 0.21 AP42 1.3NG Heaters/Boilers/Burners lbs/mmscf 7.6 0.593 100 5.5 84 AP42 1.4-1, 1NG Flares lbs/mmscf 0.593 71.4 60.3 388.5 AP42 1Liquid Flaring lbs/bbl 0.42 6.83 2 0.01 0.21 AP42 1.3-Tank Vapors lbs/bbl 0.03 E&P FFugitives lbs/hr/comp. 0.0005 API SGlycol Dehydrator Vent lbs/mmscf 6.6 La. DGas Venting lbs/scf 0.0034

Sulphur Content Source Value Units

Fuel Gas 3.33 ppm

Diesel Fuel 0.4 % weight

Produced Gas( Flares) 3.33 ppm

Produced Oil (Liquid Flaring) 1 % weight

FORM BOEM-0139 (October 2011 - Supersedes all previous versions of form BOEM-0139 which may not be used). Page 2 
AIR EMISSIONS CALCULATIONS - FIRST YEAR

COMPANY AREA BLOCK LEASE PLATFORM WELL CONTACT PHONE REMARKS

Eni US Operating Co. Inc. Green Canyon 298 G08010 007 (to be renamed SS007) Brenda Montalvo (713) 393-6259

OPERATIONS EQUIPMENT RATING MAX. FUEL ACT. FUEL RUN TIME MAXIMUM POUNDS PER HOUR 

Diesel Engines HP GAL/HR GAL/D

Nat. Gas Engines HP SCF/HR SCF/D

Burners MMBTU/HR SCF/HR SCF/D HR/D DAYS PM SOx NOx VOC CO PM 

DRILLING PRIME MOVER>600hp diesel 29556 1427.5548 34261.32 24 60 20.83 95.57 716.11 21.48 156.24 15.00 

Drillship PRIME MOVER>600hp diesel 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

BURNER diesel 0 0 0 0.00 0.00 0.00 0.00 0.00 0.00 VESSELS>600hp diesel(crew) 2065 99.7395 2393.75 10 7 1.46 6.68 50.03 1.50 10.92 0.05 VESSELS>600hp diesel(supply) 2065 99.7395 2393.75 12 13 1.46 6.68 50.03 1.50 10.92 0.11 VESSELS>600hp diesel(tugs) 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

PIPELINE PIPELINE LAY BARGE diesel 8800 425.04 10200.96 24 9 6.20 28.45 213.22 6.40 46.52 0.67 

INSTALLATION SUPPORT VESSEL diesel 2065 99.7395 2393.75 24 9 1.46 6.68 50.03 1.50 10.92 0.16 

PIPELINE BURY BARGE diesel 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

SUPPORT VESSEL diesel 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

FACILITY DERRICK BARGE diesel 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 INSTALLATION MATERIAL TUG diesel 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

VESSELS>600hp diesel(crew) 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

VESSELS>600hp diesel(supply) 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

PRODUCTION RECIP.<600hp diesel - North Crane (1) 174 8.4042 201.70 24 365 0.38 0.56 5.37 0.43 1.16 1.68 

RECIP.<600hp diesel - South Crane (1) 174 8.4042 201.70 24 365 0.38 0.56 5.37 0.43 1.16 1.68 

RECIP.<600hp diesel - Firewater Pump #1 375 18.1125 434.70 24 365 0.83 1.21 11.56 0.93 2.50 3.62 

RECIP.<600hp diesel - Firewater Pump #2 (1) 375 18.1125 434.70 24 365 0.83 1.21 11.56 0.93 2.50 3.62 RECIP.<600hp diesel - Auxiliary Generator (1) 536 25.8888 621.33 24 365 1.18 1.73 16.53 1.32 3.58 5.17 RECIP.<600hp diesel - Emergency Generator (1) 280 13.524 324.58 24 365 0.62 0.91 8.63 0.69 1.87 2.70 RECIP.<600hp diesel - Escape Capsule #1 (1) 36 1.7388 41.73 24 365 0.08 0.12 1.11 0.09 0.24 0.35 RECIP.<600hp diesel - Escape Capsule #2 (1) 36 1.7388 41.73 24 365 0.08 0.12 1.11 0.09 0.24 0.35 RECIP.<600hp diesel - Escape Capsule #3 (1) 36 1.7388 41.73 24 365 0.08 0.12 1.11 0.09 0.24 0.35 RECIP.<600hp diesel - Auxiliary Air Compressor (1) 75 3.6225 86.94 24 365 0.17 0.24 2.31 0.19 0.50 0.72 RECIP.>600hp diesel - Turbine Diesel Generator #1 (1) 6130 296.079 7105.90 24 365 4.32 19.82 148.52 4.46 32.41 18.92 RECIP.>600hp diesel - Turbine Diesel Generator #2 (1) 6130 296.079 7105.90 24 365 4.32 19.82 148.52 4.46 32.41 18.92 SUPPORT VESSEL diesel (1) 2400 115.92 2782.08 24 365 1.69 7.76 58.15 1.74 12.69 7.41 

ROV/Intervention Vessel diesel (1) 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

TURBINE nat gas - HPC Turbine Compressor (1) 10310 98192.44 2356618.56 24 365 7.27 0.06 29.52 0.23 18.85 31.83 TURBINE nat gas - Turbine Natural Gas Generator #1 (1) 6130 58382.12 1401170.88 24 365 4.32 0.03 17.55 0.14 11.21 18.92 TURBINE nat gas - Turbine Natural Gas Generator #2 (1) 6130 58382.12 1401170.88 24 365 4.32 0.03 17.55 0.14 11.21 18.92 

RECIP.4 cycle lean nat gas 0 0 0.00 0 0 0.00 0.00 0.00 0.00 

RECIP.4 cycle rich nat gas 0 0 0.00 0 0 0.00 0.00 0.00 0.00 

BURNER nat gas 0 0.00 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 MISC. BPD SCF/HR COUNTTANK- Dry Oil Storage Tank 10000 24 365 12.50 

TANK- Wet Oil Storage Tank 10000 24 365 0.00 0.00 12.50 0.00 

FLARE- 0 0 0 0.00 

PROCESS VENT- 0 0.00 FUGITIVES- 11500.0 365 5.75 

GLYCOL STILL VENT- 0 0 0 0.00 

DRILLING OIL BURN 0 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

WELL TEST GAS FLARE 0 0 0 0.00 0.00 0.00 0.00 

2015 YEAR TOTAL 62.26 198.36 1563.92 79.46 368.27 151.1

EXEMPTION 

CALCULATION DISTANCE FROM LAND IN MILES 3130.2

94.0

Drill, complete, and install leproduction from Lease G 08

FORM BOEM-0139 (October 2011- Supersedes all previous versions of form BOEM-0139 which may not be used). Page 3 
AIR EMISSIONS CALCULATIONS - SECOND YEAR

COMPANY AREA BLOCK LEASE PLATFORM WELL CONTACT PHONE REMARKS

Eni US Operating Co. Inc.Green Canyon 298 G08010 007 (to be renamed SS007) Brenda Montalvo (713) 393-6259

OPERATIONS EQUIPMENT RATING MAX. FUEL ACT. FUEL RUN TIME MAXIMUM POUNDS PER HOUR 

Diesel Engines HP GAL/HR GAL/D

Nat. Gas Engines HP SCF/HR SCF/D

Burners MMBTU/HR SCF/HR SCF/D HR/D DAYS PM SOx NOx VOC CO PM 

DRILLING PRIME MOVER>600hp diesel 0 0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

PRIME MOVER>600hp diesel 0 0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

PIPELINE PIPELINE LAY BARGE diesel 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

INSTALLATION SUPPORT VESSEL diesel 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

PIPELINE BURY BARGE diesel 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

FACILITY DERRICK BARGE diesel 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

INSTALLATION MATERIAL TUG diesel 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

VESSELS>600hp diesel(crew) 0 0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

VESSELS>600hp diesel(supply) 0 0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

PRODUCTION RECIP.<600hp diesel - North Crane (1) 174 8.4042 201.70 24 365 0.38 0.56 5.37 0.43 1.16 1.68 

RECIP.<600hp diesel - South Crane (1) 174 8.4042 201.70 24 365 0.38 0.56 5.37 0.43 1.16 1.68 

RECIP.<600hp diesel - Firewater Pump #1 375 18.1125 434.70 24 365 0.83 1.21 11.56 0.93 2.50 3.62 

RECIP.<600hp diesel - Firewater Pump #2 (1) 375 18.1125 434.70 24 365 0.83 1.21 11.56 0.93 2.50 3.62 RECIP.<600hp diesel - Auxiliary Generator (1) 536 25.8888 621.33 24 365 1.18 1.73 16.53 1.32 3.58 5.17 

RECIP.<600hp diesel - Emergency Generator (1) 280 13.524 324.58 24 365 0.62 0.91 8.63 0.69 1.87 2.70 

RECIP.<600hp diesel - Escape Capsule #1 (1) 36 1.7388 41.73 24 365 0.08 0.12 1.11 0.09 0.24 0.35 RECIP.<600hp diesel - Escape Capsule #2 (1) 36 1.7388 41.73 24 365 0.08 0.12 1.11 0.09 0.24 0.35 RECIP.<600hp diesel - Escape Capsule #3 (1) 36 1.7388 41.73 24 365 0.08 0.12 1.11 0.09 0.24 0.35 RECIP.<600hp diesel - Auxiliary Air Compressor (1) 75 3.6225 86.94 24 365 0.17 0.24 2.31 0.19 0.50 0.72 RECIP.>600hp diesel - Turbine Diesel Generator #1 (1) 6130 296.079 7105.90 24 365 4.32 19.82 148.52 4.46 32.41 18.92 RECIP.>600hp diesel - Turbine Diesel Generator #2 (1) 6130 296.079 7105.90 24 365 4.32 19.82 148.52 4.46 32.41 18.92 SUPPORT VESSEL diesel (1) 2400 115.92 2782.08 24 365 1.69 7.76 58.15 1.74 12.69 7.41 TURBINE nat gas - HPC Turbine Compressor (1) 10310 98192.44 2356618.56 24 365 7.27 0.06 29.52 0.23 18.85 31.83 TURBINE nat gas - Turbine Natural Gas Generator #1 (1) 6130 58382.12 1401170.88 24 365 4.32 0.03 17.55 0.14 11.21 18.92 TURBINE nat gas - Turbine Natural Gas Generator #2 (1) 6130 58382.12 1401170.88 24 365 4.32 0.03 17.55 0.14 11.21 18.92 

RECIP.4 cycle lean nat gas 0 0 0.00 0 0 0.00 0.00 0.00 0.00 

RECIP.4 cycle rich nat gas 0 0 0.00 0 0 0.00 0.00 0.00 0.00 

BURNER nat gas 0 0.00 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

MISC. BPD SCF/HR COUNTTANK- Dry Oil Storage Tank 10000 24 365 12.50 TANK- Wet Oil Storage Tank 10000 24 365 0.00 0.00 12.50 0.00 

FLARE- 0 0 0 0.00 

PROCESS VENT- 0 0 0

FUGITIVES- 11500.0 365 5.75 

GLYCOL STILL VENT- 0 0 0 0.00 

DRILLING OIL BURN 0 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

WELL TEST GAS FLARE 0 0 0 0.00 0.00 0.00 0.00 

2016 YEAR TOTAL 30.86 54.31 484.49 47.08 132.76 135.17 

EXEMPTION 

CALCULATION DISTANCE FROM LAND IN MILES 3130.20 

94.0

Drill, complete, and install leasof production from Lease G 08

FORM BOEM-0139 October 2011 - Supersedes all previous versions of form BOEM-0139 which may not be used). Page 4
AIR EMISSIONS CALCULATIONS

COMPANY AREA BLOCK LEASE PLATFORM WELL

Eni US Operating Co. Inc. Green Canyon 298 G08010 007 (t

Emitted Substance

Year

PM SOx NOx VOC 

2015 151.16 311.22 2671.76 197.50 

2016 135.17 237.86 2122.07 206.19 

Allowable 0.00 3130.20 3130.20 3130.20 

FORM BOEM-0139 (October 2011 - Supersedes all previous versions of form BOEM-0139 which may not be used). Page 
Eni US Operating Co. Inc. Page 14

Supplemental DOCD May 19, 2014 

Green Canyon Block 298 (OCS-G 08010) Public Information

SECTION I 

OIL SPILLS INFORMATION 

(a) Oil Spill Response Planning 

(2)(i) All proposed activities in this DOCD will be covered under Eni’s Regional OSRP filed by Eni US 

Operating Co. Inc., BOEM/BSEE Operator Number 02782, in accordance with 30 CFR 254, approved on 

January 21, 2014. 

(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 

Clean Gulf Associates (CGA) is the primary equipment provider and National Response Corporation 

(NRC) is a secondary equipment provider for Eni in the Gulf of Mexico Region. CGA maintains a 

dedicated fleet of vessels and other equipment permanently located at designated ports. CGA and NRC 

has the capability to plan the mobilization and rapid deployment of spill response resources on a 24 hour, 

7 days a week basis. The Incident Commander (IC) may use other service companies if additional 

equipment, materials, and personnel are needed. Refer to Appendix F of our OSRP for a listing of 

potential support services. 

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

Category Regional OSRP 

WCD DOCD WCD Regional OSRP 

WCD 

DOCD 

WCD 

Type of Activity Drilling Drilling Production >10 

Miles 

Production >10 

Miles 

Facility Location 

(Area/Block) MC 215 GC 298 MC546 GC298 

Facility Designation Well Location A Well No. 007 003 Well No. SS007 

Distance to Nearest 

Shoreline (miles) 64.5 94 38 94 

Volume 

 Storage tanks (total) 

 Uncontrolled blowout 

 Pipelines 

Total Volume 

309,470 147,099 156,816 

 1,445 

158,261 

147,099 

 1,445 

148,544 

Type of Oil(s) 

(crude, condensate, 

diesel) 

Oil Oil Oil Oil 

API Gravity 34° 43° 41° 43° 

Eni has determined that the worst-case scenario from the activities proposed in this DOCD do not 

supersede the worst-case scenario from our approved Regional OSRP.
Eni US Operating Co. Inc. Page 15

Supplemental DOCD May 19, 2014 

Green Canyon Block 298 (OCS-G 08010) Public Information

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

approved on January 21, 2014, therefore the worst-case scenario determined for our DOCD 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 DOCD. 

Note: Attachments associated with the calculation of the worst case discharge under this plan are under 

Section A of this plan. 

Regional OSRP 

Please view Plan Control No. N-9735

(b) Spill Response Discussion for NEPA Analysis 

Please see attached Spill Response Discussion prepared for this development plan. 

(c) Modeling Report 

Not required for the location of the activities proposed in this plan. 
GC 298

May 15, 2014

Worst Case Discharge scenario for GC 298

1) Worst Case Summary

Given the anticipated reservoir thickness and historical productivity index ENI Petroleum has 

estimated that the worst case discharge from activities at GC 298 is estimated to be 148,544 

barrels of oil per day for production and 147,099 barrels of oil per day for drilling. Calculations 

are based on formulas defined by BSEE regulations. 

This individual summary includes the following maps and information:

1. Overview Map

2. Offset Operators Map

3. Land Impact Probability Map

4. Aerial Surveillance Response Equipment Status Boards

5. Equipment Location Map

6. In-Situ Burn Equipment Status Boards

7. Dispersant Application Map

8. Dispersant Application Status Boards

9. Slick Containment Equipment Status Boards

10. Offshore On-Water Recovery & Storage Equipment Status Boards

11. Nearshore On-Water Recovery Equipment Status Boards

12. Shoreline Protection & Wildlife Support Status Boards

2) Facility Information

 Type of Operation: Prodcution & Drilling

 Area and Block: Green Canyon 298

 Latitude: 27 39’ 9.71” N

 Longitude: 90 16’ 45.86” W

 Distance to Shore: 94 Miles

 Water Depth: 3,400’

 API Gravity: 43° 
GC 298

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3) Worst Case Discharge Volume

a) Drilling Volume

An ADIOS 2 model was run on a similar product based on the oil that would reach the surface. 

The results indicate 28% of the product would be evaporated / naturally dispersed into the 

water column within 24 hours. Below is a table outlining the estimated applicable subsea and 

surface evaporation and dispersion quantities.

Criteria Barrels

Highest capacity well uncontrolled blowout volume 

associated with facility 147,099

Highest capacity storage tank volume associated with 

facility 0 

TOTAL WORST CASE DISCHARGE 147,099

Surface Natural Evaporation and Dispersion - 28% 

(ADIOS2) 41,188

TOTAL SPILL VOLUME REMAINING AFTER 

NATURAL SURFACE EVAPORATION & DISPERSON 105,911

b) Production Volume

An ADIOS 2 model was run on a similar product based on the oil that would reach the surface. 

The results indicate 27% of the product would be evaporated / naturally dispersed into the 

water column within 24 hours. Below is a table outlining the estimated applicable subsea and 

surface evaporation and dispersion quantities.

Criteria Barrels

Highest capacity well uncontrolled blowout volume 

associated with facility 147,099

Total storage tank volume associated with facility 0 

Total capacity of pipelines associated with facility 1,445

TOTAL WORST CASE DISCHARGE 148,544

Surface Natural Evaporation and Dispersion - 27% 

(ADIOS2) 40,107

TOTAL SPILL VOLUME REMAINING AFTER 

NATURAL SURFACE EVAPORATION & DISPERSON 108,437
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4) Land Segment Identification

Land areas that could be potentially impacted by an oil spill from GC 298 were determined 

using the BOEM Oil Spill Risk Analysis Model (OSRAM) available on the BOEM website. The 

OSRAM estimates the probability that an oil spill occurring in a particular launch area will 

contact a certain county or parish within 3, 10, and 30 days. The land segment that has the 

highest probability of being impacted by the GC 298 well is Cameron, Louisiana, at 5 percent. 

Land segments identified by the model are listed in the table below. 

OCS Launch Area 44 for the Gulf of Mexico Area was utilized as the point of origin. Land 

segments identified by the model are listed below (referenced from “Oil-Spill Risk Analysis: 

Contingency Planning Statistics for Gulf of Mexico OCS Activities” – OCS Report MMS 2004-

026): 

Area and Spill Site Land Segment Contact Percent Impact Chance

(Days)

Green Canyon

298

Launch Block 

#44

Land Segment No. &

County/ Parish & State 3 10 30

Matagorda, TX -- -- 1

Galveston, TX -- -- 2

Jefferson, TX -- -- 1

Cameron, LA -- -- 5

Vermilion, LA -- -- 2

Terrebonne, LA -- 1 2

Lafourche, LA -- -- 1

Jefferson, LA -- -- 1

Plaquemines, LA -- -- 4

Note: “--“denotes a value of less than 0.5%.
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5) Resource Identification

A sample Environmental Sensitivity Index map based on the current ACP is located below. 

Land Segment Contact Areas are identified on a map in Section 11, Resource Identification
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6) Response

Eni has contracted with Clean Gulf Associates (CGA) and National Response 

Corporation (NRC) as the primary Oil Spill Removal Organizations. Contact 

information and procedures for requesting OSRO’s resources can be found in Section 

7.

Upon notification of the spill, procedures in Section 6 will be followed with the partial 

or full mobilization of the resources identified in Appendix E, depending on the 

incident complexity. The status boards, located in this Appendix, outline equipment as 

well as temporary storage equipment to be considered in order to cope with an initial 

spill. The status boards outline on-water containment, on-water recovery, temporary 

storage, aerial and vessel dispersant application, in-situ burning and shoreline 

protection equipment identified as most relevant in addressing any oil that remains 

present on the surface of the water. These status boards estimate times needed for 

procurement, load out, travel to the site and deployment. . In addition, either a fixed 

wing aircraft or helicopter would be dispatched for aerial surveillance at the spill 

location. The dispatch of aerial support will be dependent on available daylight hours, 

weather conditions, and other safety considerations. Aerial support may also be used 

to coordinate and survey response efforts (such as in-situ burning, dispersant 

application and mechanical recovery). The effectiveness of these response efforts 

can be enhanced will the use of air-based spotters, who can guide these systems to 

the different oil concentrations and assist will the coordination of simultaneous 

operations. Air-based spotters may be equipped with air to marine/ground 

communication equipment.

The Qualified Individual, Person in Charge, Incident Commander or designee may 

contact other service companies if the Unified Command deems such services 

necessary to the response effort

Simultaneous operations (SIMOPS) may involve different companies working in close 

proximity on identical and/or different tactical objectives. SIMOPS can be either 

subsea operations, surface operations or a combination of both. These operations 

must be well planned and coordinated. SIMOPS will be evaluated daily and 

coordinated based on the response efforts needs, as well as, additional criteria’s (e.g. 

meteorological conditions, sea state, etc.). Regular communications will be 

established and maintained during all SIMOPS activities. 

SIMOPS activities may include but are not limited to the 

following:

• Dispersant Application (Aerial, Vessel, and Subsea)

• In-situ Burning

• Mechanical Recovery

• Nearshore / Shoreline Response

• Source Control
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6) Response (Cont’d)

Vessel locations may also be monitored with real-time vessel tracking technologies, 

such as Automated Identification Systems (AIS), GPS tracking, cell phone data, etc. 

These technologies may be used to direct vessels to the appropriate areas of oil 

concentration to enhance encounter rates.

The company will maintain an effective and well-coordinated response effort for the 

duration of the response effort to control the source of the spill and to the point when 

the Federal On-Scene Coordinator deems the response effort complete.

Response Technologies Discussion

This section discusses various response technologies (in no prioritized order) that 

might be employed during a response to a discharge of oil. The particular response 

technologies applied during a spill event will be coordinated based on the most 

accurate and up-to-date knowledge of the situation, which will determine the types of 

technology to be used, the locations at which particular technologies are applied, and 

the implementation of simultaneous operations (SIMOPS).

Eni will work with their OSRO(s) to establish a remote sensing program during an 

incident. The goal of the remote sensing program is to integrate a common operating 

picture for the entire response. Remote sensing capabilities will be used on aircraft, 

vessels, and other platforms as appropriate. The following table outlines some of the 

goals of a remote sensing program.

• Determine the location of an oil slick

• Determine oil thickness

• Operate day and night, if safe to do so

• Operate under adverse weather conditions, if safe to do so

• Have the ability to work long distance offshore

• Ability to update and provide information in pre-determined 

timeframe

• Acceptance of upgrades in capacities
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May 15, 2014

6) Response (Cont’d)

Extended Response Operations

For an extended response to an uncontrolled well blowout of up to 120 days, 

additional provisions for sustained operations and source control will be implemented 

by the Unified Command as necessary. These options may include but are not limited 

to the following:

Extended Response Options

 Command Post Coordination

 Expanded Community Relations and Public Awareness

 Expanded GIS and Satellite Imagery Coordination

 Expanded Safety and Monitoring Programs

 Expanding Staging Areas and Decontamination Sites

 Extended Logistics and Procurement

 Extended Wildlife Response and Care

 Personnel Staffing and Resource

 Relief Well Drilling

 Subsea Containment

 Vessel of Opportunity Program

 Volunteer Programs

 Well Control Technologies

a) Offshore Response

Offshore response strategies may include skimming with Oil Spill Response Vessels 

(OSRVs), Oil Spill Response Barges (OSRBs), and Quick Strike OSRVs. 

An initial response will likely consist of an Oil Spill Response Vessel (OSRV) due to 

quick mobilization and response time of these dedicated vessels. All estimated 

response times are captured in the status boards above. Additional response 

equipment and resources will begin cascading to the site or staging area(s). An 

offshore response will consist of simultaneous operations of containment booming 

and skimming operations. Dispersant application and in-situ burn operations will be 

evaluated by the Unified Command, and if approved, these techniques will be used in 

the simultaneous operations. The following equipment categories maybe used in the 

following offshore response strategies:
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Offshore Response Strategies

•

Mechanical recovery efforts using vessels, barges, ocean boom, 

skimming equipment, and spotter aircraft. These resources will be 

deployed close to the source in order to contain and collect the 

maximum amount of oil and enhancing encounter rates. This may 

include mechanical recovery vessels and barges equipped with ocean 

boom systems and/or mechanical recovery vessels and barges that 

will deploy skimming systems on vessels of opportunity to contain and 

recover oil that strays from the source area.

•

Spotter aircraft may be utilized to assist and direct skimming vessels 

and barges to areas of concentrated oil to ensure maximum encounter 

rates. Aerial and vessel communications will be established using the 

appropriately chosen communications system coordinated through the 

OSRO(s) and the FOSC.

•

Deployment of offshore resources with night sensing capabilities to 

enhance slick tracking during night time operations. The use of night 

sensing capabilities (e.g. x-band radar systems, infrared cameras, 

etc.) will assist deployment of assets to areas consisting of the 

thickest oil to enhance the encounter and recovery rates. These night 

operations will only commence if it is deemed safe to do so.

•

Upon approval, In-situ burn assets will be deployed outside of the 

source area in a U configuration to collect and burn oil in heavy 

concentrated areas.

•

Upon approval, dispersant application to disperse oil. Approved 

dispersant operations may consist of subsea and/or surface 

dispersant applications. Dispersant application requires the 

appropriate Regional Response Team (RRT) approval and will be in 

compliance with the RRT IV & VI guidelines.

For additional information regarding offshore response strategies, refer to the 

MSRC/CGA dual edition Gulf of Mexico Deep Blue Response Tactics Guidebook and 

the National Response Corporation’s Spill Response Guidebook.
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Surveillance

Upon notification of a release and mobilization of the response, either a fixed-wing 

aircraft or helicopter would be dispatched as promptly as possible (considering 

available daylight hours, weather conditions and other safety factors) to conduct 

visual surveillance at the spill source. If necessary and safe, this surveillance could be 

supplemented through use of vessels as well. The effectiveness of many response 

technologies (such as in-situ burning, dispersant application and mechanical 

recovery) can be enhanced through collaboration with air-based spotters, who can 

guide these systems to the greatest oil concentrations and coordinate simultaneous 

operations (SIMOPS). Air-based spotters shall be equipped with air to marine/ground 

communication equipment to facilitate communications with marine - and landbased 

response assets. Vessel locations may also be monitored in real-time using vesseltracking technologies (such as Automated Identification Systems (AIS) data, GPSbased tracking, cell phone data, etc.), which can facilitate vessels being deployed for 

optimal recovery. Additional information regarding methods of identifying and tracking 

a spill on water are discussed in Section 10.
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Mechanical Cleanup Methods

Mechanical oil spill response uses physical barriers (boom) and mechanical devices 

(skimmers) to redirect and remove oil from the surface of the water.

Mechanical Cleanup Methods

•

Skimming systems will deploy boom in several different 

configurations. Generally, boom will be deployed in a Jconfiguration for a high EDRC rated single skimming unit. This 

usually requires only one support vessel to attend the boom. 

Single skimming units will be located in the heavy concentrated oil 

and can be assisted by a spotter plane and remote sensing 

technologies to enhance encounter rates and effective recovery. 

The system transfers recovered oil to onboard tanks for primary 

storage. The system boom may also be deployed in a Uconfiguration with an open apex to funnel oil to a single skimming 

unit. This requires the skimming vessels(s) to be positioned 

closely behind the open apex for collection and recovery.

•

For identified areas of heavy oil that cannot be addressed 

immediately by skimming vessels, containment boom will be 

deployed to contain the oil until skimming operations can 

commence in these areas. Once skimmers are on-site the oil will 

be directed to the skimming units. The oil may be dumped into 

the path of the skimming unit or boom may be configured into a Uconfiguration with an open apex to funnel oil to the awaiting 

skimming vessels.

•

Deployment of offshore resources with night sensing capabilities 

to enhance mechanical skimming activities and slick tracking 

during night time operations. The use of night sensing capabilities 

(e.g. x-band radar systems, infrared cameras, etc.) will assist 

skimming vessels to deploy assets to areas consisting of the 

thickest oil to enhance the encounter and recovery rates.

•

Vessels of opportunity (VOO) equipped with skimming systems 

will be deployed to identified locations with recoverable oil. If any 

locations are identified to contain light oil, vessels will be equipped 

with sorbent materials to pick up the lighter oil.
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Mechanical Cleanup Methods (Cont’d)

Current proven and available sensing technology for tracking oil at night includes 

hand held, boat mounted and aircraft mounted infrared sensing. Multiple new oil 

sensing technologies (radar, satellite imagery, fluorometry, etc.) which can aid in a 

response are being reviewed and developed by industry. These and any other new 

oil sensing technologies that become available will be deployed with the purpose of 

improving the ability of keeping deployed oil skimming platforms in the most highly 

concentrated areas of spilled oil and may be used to potentially improve the 

capabilities to skim beyond traditional daylight hours. However the latter capability 

can only be implemented taking all aspects of safe operations in account and 

ensuring that there is no additional risk to human life.

Mechanical oil spill response uses physical barriers (boom) and mechanical devices 

(skimmers) to redirect and remove oil from the surface of the water. 

 

Dispersant Application

Applying dispersant from aerial, vessel, and subsea applications may be a viable 

response option and will require the appropriate approvals as outlined in Section 18, 

Dispersant Use Plan. All dispersant application methods must be approved by the 

appropriate RRT and will be in compliance with RRT IV and VI guidelines.

A listing of the Aerial Dispersant Equipment is located on the status boards within this 

Section. 

Aerial Dispersant Application

Dispersants from aerial applications may be viable response options and will require 

the appropriate approvals as outlined in Section 18, Dispersant Use Plan. 

If deemed appropriate and with approval, aerial dispersant application can be utilized 

with dispersant equipment listed above. Assuming a 1:20 application rate, 90% 

effectiveness, and 4-5 sorties per day.

Vessel Based Dispersant Application

Vessel-based dispersant application is another available response option. In previous 

responses, boat-spray systems were used for both dispersing oil and suppressing 

vapors near the spill source on the water surface. Vessel-based dispersants are also 

applied under the direction and approval of a designated Federal On-Scene 

Coordinator (FOSC), and in a manner consistent with the National Contingency Plan 

and the applicable Regional Response Plan(s) and/or Area Contingency Plans 

(ACPs). 

If appropriate, vessel spray systems can be installed on offshore vessels of 

opportunity to apply dispersants at the source or at other areas where there are 

significant concentrations of oil. Using inductor nozzles installed on fire-water 

monitors, skid mounted systems, or purpose-built boom-arm spray systems, vessels 

can initially apply dispersant within the first 12 to 24 hours of the response, and 

thereafter as needed. 
GC 298

May 15, 2014

Vessel Based Dispersant Application (Cont’d)

Priorities for dispersant use and rationing of existing supplies will be determined on an 

incident specific basis to allow for maximum effectiveness of dispersants. Dispersant 

use will be dictated by approval, safety, weather, and sea states before application 

and coordinated with Unified Command. In addition, after assessing the situation and 

notifications will be made within 48 hours of the initial spill to begin ramping up 

dispersant production through Nalco, as discussed in Section 18, Dispersant Use 

Plan. 

All dispersant application will be in compliance with RRT IV and VI guidelines.

For additional information regarding dispersant response strategies, refer to the 

MSRC/CGA dual edition Gulf of Mexico Deep Blue Response Tactics Guidebook and 

the National Response Corporation’s Spill Response Guidebook.

In-situ Burning

Open-water in-situ burning (ISB) also may be used as a response strategy,

depending on the circumstances of the release. ISB services may be provided by the 

primary OSRO contractors. If appropriate conditions exist and approvals are granted, 

one or multiple ISB task forces could be deployed offshore. 

Task forces typically consist of two to four fire teams, each with two vessels capable 

of towing fire boom, guide boom or tow line with either a handheld or aeriallydeployed oil ignition system. At least one support/safety boat would be present 

during active burning operations to provide logistics, safety and monitoring support. 

Depending upon a number of factors, up to 4 burns per 12-hour day could be 

completed per ISB fire team. Most fire boom systems can be used for approximately 

8-12 burns before being replaced. Fire intensity and weather will be the main 

determining factors for actual burns per system. Although the actual amount of oil 

that will be removed per burn is dependent on many factors, recent data suggests 

that a typical burn might eliminate approximately 750 barrels. For planning purposes 

and based on the above assumptions, a single task force of four fire teams with the 

appropriate weather and safety conditions could complete four burns per day and 

remove up to ~12,000 bbls/day. 

After assessing the situation and notification should be made within the 48 hours of 

the initial spill to begin ramping up fire boom production through contracted OSRO(s) 

as discussed in Section 19, In-situ Burn Plan. 

Considerations and limitations to ISB include atmospheric and sea conditions, oil 

weathering, air quality impacts, safety of response workers, and risk of secondary 

fires. All safety considerations will be evaluated. Additional information on ISB is 

presented in Section 19, In-situ Burn Plan. 

For additional information regarding in-situ burning response strategies, refer to the 

MSRC/CGA dual edition Gulf of Mexico Deep Blue Response Tactics Guidebook.
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Well Containment

The initial response to a well blowout would be an attempt to activate the blowout 

preventers and close the well. The Source Control team will be stood up immediately 

with notifications to the primary well control provider, Helix Well Containment Group

(HWCG) in the event of a blowout. The first step will be determining the method for 

source control (ie. capped and killed or captured and flow). These options will be 

determined prior to drilling using the Well Containment Screening Tool.

Subsea containment resources would be mobilized in the event of an uncontrolled 

well blowout. Subsea containment incorporates simultaneous operations to cap or 

contain the flow of oil within the well, contain the oil outside of the well and collect at 

surface facilities or vessels and chemically disperse the oil at the well head. HWCG

has been contracted to supply the subsea dispersant applications.

Subsea containment activities, including Source Control are addressed in Appendix I.

Source Control Activities

 Notifications to regulatory authorities, HWCG, and 

support contractors regarding well control incident

 Site assessment, initial response, and well monitoring



Notification and activation of any equipment and 

contract services outside of HWCG will be initiated by 

Eni (e.g. shuttle tankers, helicopters, etc.)



Notification, as needed, to members of HWCG to assist 

Eni’s Source Control Group during source control 

operations

 Debris Removal and Lower Marine Riser Package 

(LMRP) Recovery Considerations, if applicable



Coordination of ROVs, support vessels, intervention 

vessels, subsea dispersant equipment, subsea 

dispersant application, debris removal tools, umbilical, 

chemical delivery, pumping services, and other 

equipment for WCD scenarios

 Run Intervention Riser System

 Well Capping and Shut-in Operation Activities

For additional detailed information on these systems, their components, and 

deployment times, refer to the current Marine Well Containment Company Interim 

Containment Response System Functional Specifications USWC-ED-BPFEP-000001 

provided to BSEE by HWCG. Information on how these systems will be deployed to 

respond to a specific well, can be found in the NTL 2010-N10 information submitted 

as a supplement to the individual “Application for Permit to Drill.”
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b) Nearshore and Shoreline Protection

If a nearshore spill were to occur, shoreline impact would depend upon existing 

environmental conditions. Nearshore response may include the deployment of 

shoreline boom on beach areas, or protection and sorbent boom on vegetated areas, 

as well as shallow water response strategies. Sorbent boom is a readily available 

resource and can be acquired as needed. OSRO’s have resources which can be 

deployed for a shoreline cleanup effort (equipment locations are depicted on the 

Equipment Location map), as well as the contractor Shoreline Protection & Wildlife 

Support Status Board in this section. CGA maintains the PRO’s program. This is a 

list of subcontractors that may be called upon for assistance for the 

nearshore/shoreline response.

Strategies would be based upon surveillance and real time trajectories provided by 

The Response Group that depict areas of potential impact given actual sea and 

weather conditions. Strategies from the Area Contingency Plan, The Response Group 

and Unified Command would be consulted to ensure that environmental and special 

economic resources would be correctly identified and prioritized to ensure optimal 

protection. The deployment of nearshore resources with night sensing capabilities to 

enhance slick tracking may be used during night time operations. The use of night 

sensing capabilities (e.g. x-band radar systems, infrared cameras, etc.) will assist 

deployment of assets to areas consisting of the thickest oil to enhance the encounter 

and recovery rates.

For additional information regarding Nearshore and Shoreline response strategies, 

refer to the MSRC/CGA dual edition Gulf of Mexico Deep Blue Response Tactics 

Guidebook, the National Response Corporation’s Spill Response Guidebook, the 

Area Contingency Plans, and the appropriate Shoreline Response Strategy 

Guidebook developed by The Response Group.

Surveillance

Either a fixed-wing aircraft or helicopter will conduct visual surveillance to assess the 

situation and assist in coordinating Nearshore and Shoreline response activities. If 

necessary and safe, this surveillance could be supplemented through use of vessels 

as well. The effectiveness of many response technologies (such as in-situ burning, 

dispersant application and mechanical recovery) can be enhanced through 

collaboration with air-based spotters, who can guide these systems to the oil 

concentrations and coordinate simultaneous operations (SIMOPS). Air-based spotters 

may be equipped with air to marine/ground communication equipment to facilitate

communications with marine- and land-based response assets. Vessel locations may 

also be monitored in real-time using vessel-tracking technologies (such as Automated 

Identification Systems (AIS) data, GPS-based tracking, cell phone data, etc.), which 

can facilitate vessels being deployed for optimal recovery. Additional information 

regarding methods of identifying and tracking a spill on water are discussed in Section 

10.
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Mechanical Cleanup Methods

In order to minimize shoreline impact, mechanical recovery resources will be deployed to 

contain and collect oil. In shallow water areas, it may be possible to collect and corral oil with 

ocean boom and move it to deeper water or low-current areas that allow for better skimmer 

access and higher encounter and recovery rates. Skimmers will also be deployed in natural 

collection points along the shoreline.

This table outlines some of the water-borne tactics that may be used in 

a shallow water environment

• Shallow Water Barge Skimming (SBS)

• Combination FRV/SBS

• Shallow Water Skimmers

• Shallow Water Recovery Barge (Skimming System/Shuttle Barge)

This table outlines an example of land-based tactics that may be used 

in shallow water environments

• Vacuum Trucks

• Shore-side Skimmers

• Sorbent Materials

For additional information regarding mechanical response strategies, refer to the MSRC/CGA 

dual edition Gulf of Mexico Deep Blue Response Tactics Guidebook and the National Response 

Corporation’s Spill Response Guidebook.
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Dispersant Applications

Dispersant use within 10 miles of shore will be considered on a case-by-case basis. 

Consideration will be given according to the location of the spill material, distance from shore, 

water depth, trajectory modeling, and environmental impacts of a non-dispersed spill. The Near 

Shore Environmental Dispersant Expedited Approval Process (NSE EAP) Initial Call and 

Minimum Criteria Checklists are located in Figure 18-11 and Figure 18-12. If deemed 

appropriate and with approval, aerial dispersant application can be utilized aerial dispersants 

denoted in the Status Boards above. It is assumed there will be a 1:20 application rate, 90% 

effectiveness with the ability to conduct 4-5 sorties per day. 

Vessel dispersant application may be another available response option. If appropriate, vessel 

spray systems can be installed on offshore vessels of opportunity using inductor nozzles 

(installed on fire-water monitors), skid mounted systems, or purpose-built boom arm spray 

systems. Vessels can apply dispersant within the first 12-24 hours of the response and 

continually as directed. 

All dispersant applications will be in compliance with the RRT IV and VI guidelines.

For additional information regarding dispersant response strategies, refer to the MSRC/CGA 

dual edition Gulf of Mexico Deep Blue Response Tactics Guidebook and the National 

Response Corporation’s Spill Response Guidebook.

In-situ Burning

In-situ burning nearshore and along shorelines may be a possible option based on several 

conditions and with appropriate approvals from the RRT, as outlined in Section 19, In-situ Burn 

Plan. In-situ burning along certain types of shorelines may be used to minimize physical 

damage where access is limited or if it is determined that mechanical/manual removal may 

cause a substantial negative impact on the environment. All safety considerations will be 

evaluated. 

Additional information on ISB is presented in Section 19, the In-Situ Burn Plan. In addition, 

after assessing the situation and notifications will be made within 48 hours of the initial spill to 

begin ramping up fire boom production through contracted OSRO(s) as discussed in Section 

19, the In-situ Burn Plan.

For additional information regarding in-situ burning response strategies, refer to the 

MSRC/CGA dual edition Gulf of Mexico Deep Blue Response Tactics Guidebook and the 

National Response Corporation’s Spill Response Guidebook.
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Shoreline Protection

The Response Group’s Shoreline Response Guides 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. The following 

are various types of boom that may be deployed to protect the shoreline.

Shoreline Boom Options

Near Shore Booming

When oil impact threatens shoreline or marshes. 

Medium size boom (~18”) to deflect or contain oil 

or use to prevent impact to sensitive areas.

Bottom-Seal Boom

Typically used in shallow water with highercurrents. The shallow skirt minimizes the drag in 

the current and allows it to conform to the 

substrate so that it can continue to act as a barrier 

to oil during changing tides or lower water levels. 

Bottom seal boom uses ballast tubes that are filled 

with water and lies on the bottom to provide a seal 

against oil passage.

Inland Boom

Inland boom is the smallest conventional boom 

and is designed for deployment in very shallow 

water; as the draft is only 6-12 inches. It is 

normally deployed in more protected waters where 

there is little or no wave action.

Sorbent Boom

Deployed to absorb oil and act as a protective 

measure against thin oil sheens under very quiet 

water conditions. Snare boom may be used for 

more viscous oils under higher wave and current 

conditions. Sorbent booms effectiveness is limited 

to only the thinnest sheens.

For more information on resource identification and protection methods, see Section 11, 

Resource Identification. A time frame for the mobilization of equipment is outlined in Section 

14, Mobilization & Deployment Methods, based on equipment locations. See Section 15, Oil & 

Debris Removal for additional shoreline cleanup and protection methods.

For additional information regarding shoreline response strategies, refer to the MSRC/CGA 

dual edition Gulf of Mexico Deep Blue Response Tactics Guidebook, the National Response 

Corporation’s Spill Response Guidebook, the Area Contingency Plans, and the appropriate 

Shoreline Response Strategy Guidebook developed by The Response Group.

Wildlife Support

If wildlife is threatened due to a spill, the OSRO’s have resources available that can be utilized 

to protect and rehabilitate wildlife. See Appendix E, Response Equipment, for details on the 

available resources, and Section 17, Wildlife Rehabilitation Procedures, for further details on 

the protection and rehabilitation of affected wildlife and contacts for available wildlife protection 

and rehabilitation providers.
Eni US Operating Co. Inc. Page 16

Supplemental DOCD May 19, 2014

Green Canyon Block 298 (OCS-G 08010) Public Information

SECTION J 

ENVIRONMENTAL MONITORING INFORMATION 

(a) Monitoring Systems 

There are no environmental monitoring systems currently in place or planned for the proposed activities.

(b) Incidental Takes 

No incidental takes are anticipated. Eni implements the mitigation measures and monitors for incidental 

takes of protected species according to the following notices to lessees and operators from BOEM/BSEE: 

• NTL 2012-G01 “Marine Trash and Debris Awareness and Elimination” 

• NTL 2012-Joint-G01 “Vessel Strike Avoidance and Injured/Dead Protected Species Reporting” 

• NTL 2012-Joint G02 “Implementation of Seismic Survey Mitigation Measure & Protect Species 

Observer Program” 

SECTION K 

LEASE STIPULATIONS INFORMATION 

Marine Protected Species 

Eni will operate in accordance with NTL 2012-Joint-G01 “Vessel Strike Avoidance and Injured/Dead 

Protected Species Reporting” and NTL 2012-Joint G02 “Implementation of Seismic Survey Mitigation 

Measure & Protect Species Observer Program”, 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.

SECTION L 

ENVIRONMENTAL MITIGATION MEASURES INFORMATION 

(a) Measures Taken to Avoid, Minimize, and Mitigate Impacts 

The proposed action will implement mitigation measures required by laws and regulations, including all 

applicable Federal & State requirements concerning air emissions, discharges to water, and solid waste 

disposal, as well as any additional permit requirements and Eni policies. Project activities will be 

conducted in accordance with the Regional OSRP. 

(b) Incidental Takes

Eni US Operating Co. Inc. does not anticipate any incidental takes related to the proposed operations. Eni 

implements the mitigation measures and monitors for incidental takes of protected species according to 

the following notices to lessees and operators from BOEM/BSEE: 

• NTL 2012-G01 “Marine Trash and Debris Awareness and Elimination” 

• NTL 2012-Joint-G01 “Vessel Strike Avoidance and Injured/Dead Protected Species Reporting” 

• NTL 2012-Joint G02 “Implementation of Seismic Survey Mitigation Measure & Protect Species 

Observer Program” 
Eni US Operating Co. Inc. Page 17

Supplemental DOCD May 19, 2014 

Green Canyon Block 298 (OCS-G 08010) Public Information

SECTION M 

RELATED FACILITIES AND OPERATIONS INFORMATION 

(a) Related OCS Facilities and Operations 

The subject well will have a 10K horizontal tree mounted on the top of the wellhead in approximately 

3200’(feet) water depth. Subsea wells on the continent shelf in the GoM in such deep water usually do 

not have any protective structures since they are far away from the coastal and shallow water areas (state 

water) where fishing and navigation activities are frequent. 

A 6-inch insulated lease-term oil pipeline approximately 2.3 miles in length will be installed to transport 

produced hydrocarbons from Green Canyon Block 298, Well No. 007 to the South Riser Manifold (REM) 

at Green Canyon Block 298, associated with a 4-inch jumper to the Allegheny A Platform TLP in Green 

Canyon Block 254 (Complex ID 251) through one of the existing 4.5-inch steel catenary risers (SCRs). 

The maximum flow rate is estimated to be 9,000 barrels of crude oil per day. The pipeline boarding 

shutdown valve (BSDV) at the Allegheny TLP meets the 45 second shut-in requirement as set forth in 

the NTL No. 2009-G36.

Eni anticipates installing minimal processing equipment on this structure. All hydrocarbon handling 

equipment installed for testing and production operations will be designed, installed and operated to 

prevent pollution. 

(b) Transportation System

As stated in (a) above, a pipeline will be installed to transport produced hydrocarbons from the proposed 

well site to the existing structure in Green Canyon Block 254-A. No new nearshore or onshore pipelines 

or facilities will be constructed. 

(c) Produced Liquid Hydrocarbons Transportation Vessels 

There will not be any transfers of liquid hydrocarbons other than via pipeline.

Eni US Operating Co. Inc. Page 18

Supplemental DOCD May 19, 2014 

Green Canyon Block 298 (OCS-G 08010) Public Information

SECTION N 

SUPPORT VESSELS AND AIRCRAFT INFORMATION 

(a) General 

Type Maximum Fuel Tank 

Capacity 

Maximum 

Number in Area 

at Any Time

Trip Frequency or 

Duration 

Crew Boat 1500 bbls 1 1 per week 

Supply Boat 2500 bbls 2 2 per vessel per week 

Helicopter 286 gallons 1 1 per day 

ROV Installation Vessel 10,000 bbls 1 9 days 

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

utilized. 

(b) Diesel Oil Supply Vessels 

A ROV vessel will be used to install jumpers. Eni will not use a diesel oil supply vessel for this 

operation. 

Size of Fuel Supply 

Vessel 

Capacity of Fuel 

Supply Vessel 

Frequency of Fuel 

Transfers 

Route Fuel Supply 

Vessel Will Take 

240 Foot 2500 Barrels 3 per month Port Fourchon to 

GREEN CANYON 

BLOCK 298

 

(c) Drilling Fluid Transportation 

This table is required for operations in the State of Florida and is not required in this plan. 

(d) Solid and Liquid Waste Transportation 

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

(e) Vicinity Map 

Enclosed 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. 
Eni US Operating Co. Inc. Page 19

Supplemental DOCD May 19, 2014 

Green Canyon Block 298 (OCS-G 08010) Public Information
Eni US Operating Co. Inc. Page 20

Supplemental DOCD May 19, 2014 

Green Canyon Block 298 (OCS-G 08010) Public Information
Eni US Operating Co. Inc. Page 21

Supplemental DOCD May 19, 2014 

Green Canyon Block 298 (OCS-G 08010) Public Information

SECTION O 

ONSHORE SUPPORT FACILITIES INFORMATION 

(a) General 

The table below is the onshore facilities that will be used to provide supply and service support for the 

proposed activities under this plan:

Name of Shorebase Location Existing/New/Modified 

Fourchon, LA – Gulf Offshore 

Logistics 

300 AT Gisclair Road 

Fourchon, LA 70357 

Existing 

PHI Heliport Houma, 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 plan. 

(c) Support Base Construction or Expansion Timetable 

Eni will not expand the existing shorebase as a result of the operations proposed in this DOCD. 

(d) Waste Disposal 

TABLE 2: 

WASTES YOU WILL TRANSPORT AND /OR DISPOSE OF ONSHORE 
Eni US Operating Co. Inc. Page 22

Supplemental DOCD May 19, 2014 

Green Canyon Block 298 (OCS-G 08010) Public Information
Eni US Operating Co. Inc. Page 23

Supplemental DOCD May 19, 2014 

Green Canyon Block 298 (OCS-G 08010) Public Information

SECTION P 

COASTAL ZONE MANAGEMENT (CZMA) INFORMATION 

A certificate of Coastal Zone Management Consistency for the state(s) is not required under NTL 2008-G04 

for Supplemental Development Operations Coordination Document. 
Eni US Operating Co. Inc. Page 24

Supplemental DOCD May 19, 2014 

Green Canyon Block 298 (OCS-G 08010) Public Information

SECTION Q 

ENVIRONMENTAL IMPACT ANALYSIS (EIA) 

In accordance with the requirements of 30 CFR 550.261 an Environmental Impact Analysis (EIA) is attached. 

Attachments: 

Environmental Report 
EIA – GC298 

MAY 2014 

APPENDIX 19 

Environmental Impact Analysis 

(A) Impact Producing Factors 

Environmental Impact Analysis Worksheet 

Environmental 

Resources 

Impact Producing Factors (IPFs) 

Categories and Examples 

Refer to a recent Gulf of Mexico Outer Continental Shelf Lease 

Sale EIS for a more complete list of IPFs 

Emissions 

(air, noise, 

light, etc.) 

Effluents 

(muds, 

cuttings, 

other 

discharges 

to the water 

column or 

seafloor) 

Physical 

disturbances 

to the seafloor 

(drilling rig or 

anchor 

emplacements, 

etc.) 

Wastes 

sent to 

shore for 

treatment 

or disposal 

Accidents 

(e.g., oil 

spills, 

chemical 

spills, H2S 

releases) 

Discarded 

Trash and 

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) 

Chemosynthetic 

communities (4) 

Water quality X X X X 

Fisheries X X X 

Marine mammals X(8) X X(8) X 

Sea turtles X(8) X X(8) X 

Air quality X(9) X 

Shipwreck sites (known 

or potential (7) 

Prehistoric 

archaeological sites X(7) 

Vicinity of Offshore 

Location 

Essential fish habitat X X X(6) 

Marine and pelagic 

birds X X X 

Public health and safety (5) 

Coastal and Onshore 

Beaches X(6) X 

Wetlands X(6) 

Shore birds and coastal 

nesting birds X(6) X 

Coastal wildlife refuges X 

Wilderness areas X 

Other Resources you 

identify 
EIA – GC298 

MAY 2014 

Footnotes for Environmental Impact Analysis Matrix 

1. Activities that may affect a marine sanctuary or topographic feature. Specifically, if the well 

or platform site or any anchors will be installed on the seafloor within the: 

(a) The 4-mile zone of the Flower Garden Banks or the 3-mile zone of Stetson 

Bank; 

(b) The 1000-m, 1-mile, or 3 mile zone of any topographic feature (submarine 

bank) protected by the Topographic Features Stipulation attached to an Outer 

Continental Shelf (OCS) lease; 

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

(d) Proximity of any submarine bank (500 ft buffer zone) with relief greater than 2 

meters that is not protected by the Topographic Features Stipulation attached 

to an OCS lease. 

2. Activities with any bottom disturbance within an OCS lease block protected through the Live 

Bottom (Pinnacle Trend) Stipulation attached to an OCS lease. 

3. Activities within any Eastern Gulf OCS block where seafloor habitats are protected by the 

Live Bottom (Low-Relief) Stipulation attached to an OCS lease. 

4. Activities on blocks designated by the Bureau of Ocean Energy Management (BOEM) as 

being in water depths 300 meters or greater. 

5. Exploration or production activities where Hydrogen Sulfide (H2S) concentrations greater 

than 500 part per million (ppm) may occur. 

6. All activities potentially resulting in an accidental spill of produced liquid polycyclic aromatic 

hydrocarbons or diesel fuel that may potentially impact these environmental resources. The EIA 

may denote if the proposed action is located a sufficient distance from a resource, thus resulting 

in no impact. 

7. All activities involving seafloor disturbances (e.g. anchor placements) in any OCS block with 

a high-probability of shipwrecks or prehistoric sites occurrence (as designated by the BOEM), 

including such blocks that will be affected that are adjacent to the lease block in which the 

planned activity will occur. The EIA may denote if the proposed activities are located a sufficient 

distance from a shipwreck or prehistoric site, thus resulting in no impact. 

8. All activities that might have an adverse effect on endangered or threatened marine 

mammals or sea turtles or their critical habitats. 

9. Production activities that involve transportation of produced fluids to shore using shuttle 

tankers or barges. 
EIA – GC298 

MAY 2014 

(B) ANALYSIS 

Site-Specific at Green Canyon Area, Block 298, Well No. 7 

1. Designated Topographic Features 

Potential Impact Producing Factors (IPFs) on topographic features include physical 

disturbances to the seafloor, effluents, and accidents. 

Physical disturbances to the seafloor: Green Canyon Area, Block 298, Well No. 7 is 

located approximately 39 miles southeast of Diaphus Bank (South Timbalier Area, South 

Addition, Block 317), the nearest known topographic feature, no adverse impacts are 

expected. 

Effluents: Green Canyon Area, Block 298, Well No. 7 is located approximately 39 miles 

southeast of Diaphus Bank (South Timbalier Area, South Addition, Block 317), the nearest 

known topographic feature, no adverse impacts are expected. 

Accidents: The following discussion of topographic features is summarized from the Final 

Environmental Impact Statement (EIS; USDOI, MMS, 2002). The Topographic Features 

Stipulation (TFS) has been used on offshore energy leases located in close proximity to 

biotic communities since 1973. The TFS provides protection of biota in these areas from 

damage occurring as a result of routine oil and gas activities (Schmahl et al. 2012). In the 

unlikely event of an accidental surface or subsurface oil spill, concentrated oil is not 

expected to impact sessile biota on designated topographic features within regional 

proximity. In the northern Gulf of Mexico, a majority of topographic features occur within 150 

to 200 feet of the water’s surface (http:oceanexplorer.noaa.gov, last accessed April 2013); 

therefore, concentrated oil from a surface spill is not likely to reach sessile biota. While 

unlikely, subsurface spills may result in formation and settling of oil-saturated material with 

particles potentially reaching organisms and resulting in adverse impacts; however a 

subsurface spill is expected to disperse and stay suspended or slowly rise to the surface 

(NOAA 2010). The Eni US Operating Co. Inc. Oil Spill Response Plan will cover activities 

proposed in this DOCD. 

There are no other IPFs (including emissions, wastes sent to shore for disposal, and 

discarded trash and debris) from the proposed activities potentially impacting topographic 

features. 

2. Pinnacle Trend Area Live Bottoms

Potential IPFs on pinnacle trend area live bottoms include physical disturbances to the 

seafloor, effluents, and accidents. 

Physical disturbances to the seafloor: Green Canyon Area, Block 298, Well No. 7 is 

located approximately 154 miles southwest of Main Pass, Block 290, the nearest block 

protected by the pinnacle trend live bottom stipulation; therefore, no adverse impacts are 

expected. The following discussion of pinnacle trend areas of live bottoms is summarized 

from the Final EIS (USDOI, MMS 2002). Upon identification of pinnacles present at the 

activity site, the lessee will be advised to avoid placement of the drilling rig and anchors on 
EIA – GC298 

MAY 2014 

the identified area. Therefore, mechanical damage to the pinnacles is avoided by following 

restrictions listed in the Final EIS for pinnacle trend area live bottoms. 

Effluents: Green Canyon Area, Block 298, Well No. 7 is located approximately 154 miles 

southwest of Main Pass, Block 290, the nearest block protected by the pinnacle trend live 

bottom stipulation; therefore, no adverse impacts are expected. The stipulation does not 

address the discharge of effluents near the pinnacles because the pinnacle trend is subject 

to heavy natural sedimentation and is at considerable depths. The quick dilution of drill 

cuttings and muds will minimize the potential of significant concentration of effluents on the 

pinnacles (perf.org, last accessed April 2013). 

Accidents: In the unlikely event of an accidental surface or subsurface oil spill, 

concentrated oil is not expected to impact biota of the pinnacle trend. Any surface oil spill 

resulting from a proposed action would likely have no impact on the biota of the pinnacle 

trend because the crests of these features occur at a depth greater than 20 meters. All 

evidence to date indicates that accidental oil discharge occurring at the seafloor from 

pipelines or blowouts will rise in the water column—surfacing almost directly over the source 

location—without impacting pinnacles. In the unlikely event of an accident, adverse impacts 

to pinnacle trend area live bottoms are possible. The Eni US Operating Co. Inc. Oil Spill 

Response Plan will cover activities proposed in this DOCD. 

There are no other IPFs (including emissions, wastes sent to shore for disposal, and 

discarded trash and debris) from the proposed activities, which could impact pinnacle trend 

area live bottoms. 

3. Eastern Gulf Live Bottoms Low Relief Area

Potential IPFs on Eastern Gulf live bottoms low relief area include physical disturbances to 

the seafloor, effluents, and accidents. 

Physical disturbances to the seafloor: Green Canyon Area, Block 298, Well No. 7 is 

located approximately 194 miles southwest of the nearest block (Destin Dome 573) 

protected by the gulf live bottom stipulation, therefore, no adverse impacts are expected. 

The following discussion of eastern gulf live bottom is summarized from the Final EIS 

(USDOI, MMS 2002). Through detection and avoidance, the Eastern Gulf live bottom lease 

stipulation minimizes the likelihood of mechanical damage to the sessile and pelagic 

communities associated with the crest and flanks of such features as a result of OCS 

activities associated with drilling rig and anchor placement. 

Effluents: Green Canyon Area, Block 298, Well No. 7 is located approximately 194 miles 

southwest of the nearest block (Destin Dome 573) protected by the gulf live bottom 

stipulation, therefore, no adverse impacts are expected. Since this area is subject to heavy 

natural sedimentation, this stipulation does not include any specific measures to protect the 

pinnacles from the discharge of effluents. 

 
EIA – GC298 

MAY 2014 

Accidents: In the unlikely event of an accidental surface or subsurface oil spill, 

concentrated oil is not expected to impact Eastern Gulf live bottoms because of the features 

and dilution of spills by currents and/or quickly rising oil. However, in the unlikely event of 

an accident, adverse impacts to Eastern Gulf live bottoms are possible. Eni US Operating 

Co. Inc.’s Spill Response Plan will cover activities proposed in this DOCD. 

There are no other IPFs (including emissions, wastes delivered to shore for disposal, and 

discarded trash and debris) from the proposed activities, which could impact eastern Gulf 

live bottoms. 

4. High-Density Deepwater Benthic Communities

After careful review of the impact-producing factors (including effluents, physical 

disturbances to the seafloor, and accidents) that could result from the activities proposed 

under this DOCD; Green Canyon Area, Block 298, Well No. 7 is located approximately 6 

miles south of the nearest block (Green Canyon 210) with known chemosynthetic 

communities, it has been determined that there will be no adverse impacts to 

chemosynthetic communities. Bottom-disturbing activities proposed in this DOCD will not 

impact any deepwater benthic chemosynthetic communities, as evidenced by Fugro 

GeoConsulting, Inc., “Shallow Hazard Assessment, Allegheny Prospect, Block 298, Green 

Canyon Area, Gulf of Mexico”, Report No. 27.2014-2706 and Fugro GeoConsulting, Inc., 

“Wellsite Clearance Letter, Proposed Wellsite GC 298, Well No. 007, Block 298, Green 

Canyon Area”, Report No. 27.2014-2706-GC298-7. The water depth at the surface location 

of the proposed Green Canyon Area, Block 298, Well No. 7 is 3,206 feet. The proposed 

activities are not located within the vicinity of any known chemosynthetic communities which 

typically occur in water depths from 300 meters down to the abyssal oceanic zone (NTL 

2009-G40; www.bsee.gov). 

The water depth at the surface location of the proposed Green Canyon Area, Block 298, 

Well No. 7 is 3,206 feet. Discharge of water-based drilling fluids and cuttings at the surface 

in such water depths will be spread across broad areas of the seafloor in thin accumulations 

with very low impact expected. 

A Shallow Hazards Assessment, Report No. 27.2014-2706 dated March 24, 2014, of the 

seafloor covering the wellsite was prepared by Fugro GeoConsulting, Inc. The results of the 

seafloor assessment concluded that there were no high density deepwater benthic 

communities located within the proposed location. 

An accidental oil spill or chemical spill could have a detrimental impact on chemosynthetic 

communities; however, it is highly unlikely that this would occur. If it does occur, Eni US 

Operating Co. Inc. has an approved Oil Spill Response Plan in place which would be 

immediately put into action. There are no other IPFs (including emissions and discarded 

trash and debris) from the proposed activities which could cause impacts to chemosynthetic 

communities. 

 
EIA – GC298 

MAY 2014 

5. Water Quality

Potential IPFs resulting in water quality degradation from the proposed activities of this 

DOCD include physical disturbances to the seafloor, effluents, wastes sent to shore for 

treatment or disposal, and accidents. 

Physical disturbances to the seafloor: Bottom area disturbances resulting from the 

placement of drill rigs, the drilling of wells and the installation of platforms and pipelines will 

temporarily increase water-column turbidity and re-suspension of any accumulated 

pollutants (e.g. trace metals and excess nutrients). Increased turbidity and potential resuspension of pollutants will cause ephemeral impacts on water quality conditions in the 

immediate vicinity of the emplacement operations. 

Effluents: The discharge generated as a result of drilling and completion activities 

associated with this DOCD will be discharged upon successful bioassay tests, per NPDES 

discharge guidelines. All applicable Federal, State and Local guidelines regarding water 

quality and discharge for the proposed activities, as well as any other permit conditions, will 

be followed. 

Wastes sent to shore for treatment or disposal: Solid wastes—typically paper, plastic, 

cloth, and metal—will be collected and transported to shore for disposal at an approved 

facility. Solid wastes generated from the transportation vessels will be collected and 

returned to shore for disposal concurrent with the drilling rig refuse. Scrap metal and other 

metal wastes will be recycled or sold. Sanitary waste will be treated in approved marine 

sanitation devices as required by the Clean Water Act. All biodegradable wastes, such as 

kitchen food scraps, will be comminuted or ground and discharged in accordance with 

Annex V of MARPOL 73/78 (International Convention for the Prevention of Pollution from 

Ships, 1973 as modified by the Protocol of 1978). Hazardous waste from the drilling rig, 

such as paint and/or paint thinner, will be collected in sealed metal containers and 

transported to an approved disposal site in accordance with Resource Conservation and 

Recovery Act guidelines. 

Accidents: The following discussion of potential impacts to water quality is summarized 

from the Final Environmental Impact Statement (USDOI, MMS 2002). In the unlikely event 

of a surface or subsurface oil spill, a variety of physical, chemical, and biological processes 

are enacted to disperse the oil such as the evaporation of the more volatile constituents, 

dissolution into the water column, emulsification of small droplets, agglomeration sinking, 

microbial modification, photochemical modification, biological ingestion and excretion, and 

more. The dissolved components and small oil droplets that do not rise to the surface or are 

mixed down by surface turbulence might temporarily affect the water quality. Dispersion by 

currents and microbial degradation may remove the oil from the water column or dilute the 

constituents to background levels. Therefore, adverse impacts to water quality are possible, 

but are unlikely. Eni US Operating Co. Inc.’s Spill Response Plan will cover activities 

proposed in this DOCD. 

There are no other IPFs (including emissions and discarded trash and debris) from the 

proposed activities which could cause impacts to water quality. 

 
EIA – GC298 

MAY 2014 

6. Fisheries

Potential IPFs resulting in impacts to fisheries from the DOCD proposed activities include 

physical disturbances to the seafloor, effluents, and accidents. 

Physical disturbances to the seafloor: Since the activities proposed in this DOCD are 

located in water depths of approximately 3,206 feet, the emplacement and removal of 

facilities are not expected to cause significant adverse impacts to fisheries. 

Effluents: Effluents such as drilling fluids and cuttings discharges contain some 

components and properties that 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 3000 m of the discharge point, and are expected to have negligible effect on fisheries. 

Accidents: The following discussion of potential impacts to water quality is summarized 

from the Final Environmental Impact Statement (USDOI, MMS 2002) and the National 

Oceanic and Atmospheric Administration (NOAA). The Gulf Sturgeon (Ancipenser Oxyrincus 

desotoi) and Smalltooth Sawfish (Pristis pectinata) are the only listed threatened or 

endangered fish species in the Gulf of Mexico (www.noaa.gov, last accessed November 

2012). The current distribution of the Smalltooth Sawfish is limited to peninsular Florida. 

The activities proposed in this plan are not expected to cause adverse effects to the 

Smalltooth Sawfish. The Gulf Sturgeon may potentially be impacted by a spill, if one were to 

occur. While unlikely, contact with spilled oil may cause sublethal to lethal effects in fishes, 

depending on the amount of exposure. The likelihood of spill occurrence and contact to the 

Gulf Sturgeon and other Gulf of Mexico fish is very low. 

Should a spill occur in the area of adult finfish or shellfish, the effects will likely be sublethal 

and the extent of the damage would be dependent on the ability of the adult fishes and 

shellfishes to avoid a spill, to metabolize polycyclic aromatic hydrocarbons, and to excrete 

both metabolites and parent compounds. In the unlikely event of an accident, adverse 

impacts to fisheries are possible. Eni US Operating Co. Inc.’s Spill Response Plan will cover 

activities proposed in this DOCD. 

There are no other IPFs (including emissions, wastes sent to shore for disposal, and 

discarded trash and debris) from the proposed activities that could cause impacts to 

fisheries. 

7. Marine Mammals 

Potential IPFs potentially impacting marine mammals from the DOCD proposed activities 

include emissions, effluents, discarded trash and debris, and accidents. 

Endangered or threatened marine mammal species occurring in the Gulf of Mexico are West 

Indian Manatee (Trichechus manatus), Fin Whale (Balaenoptera physalus), Humpback 

Whale (Megaptera novaeangliae), Sei Whale (Balaenoptera borealis), Sperm Whale 

(Physeter macrocephalus), and Blue Whale (Balaenoptera musculus) (www.noaa.gov, last 

accessed September 2012). Several species of non-endangered and non-threatened 

mammal species of whales and dolphins also occur in the Gulf of Mexico. 
EIA – GC298 

MAY 2014 

Emissions: Disturbances (e.g. noise) may stress marine mammals and weaken their 

immune systems making them more vulnerable to parasites, diseases, environmental 

contaminants, and predation; however, the effect of these stressors on marine mammals is 

dependent upon the intensity and amount of exposure (Wright and Weilgart 2011). There 

are multiple studies debating whether anthropogenic noise and other disturbances cause 

long-term displacement of or population reductions in marine mammal populations. 

Effluents: Contaminants in waste discharge and drilling muds might indirectly affect marine 

mammals through food-chain bioaccumulations. Although the scope of effects and their 

magnitude are not known, direct or indirect effects are not expected to be lethal. 

Discarded Trash and Debris: Both entanglement in and ingestion of debris have caused 

death or serious injury in marine mammals (Williams et al. 2011). The marine debris, if any, 

resulting from the proposed activities is not expected to significantly affect marine mammals. 

Eni US Operating Co. Inc. will adhere to the information and guidelines set forth by the 

Marine Trash and Debris Awareness and Elimination Notice to Lessees and Operators 

(BSEE; NTL 2012-BSEE-G01). 

Accidents: Small numbers of marine mammals may experience mortality or injury by 

chance collision with service vessels. Sperm whales are one of the 11 whale species that 

are hit commonly by ships (Wilson et al. 2007). Collisions between OCS vessels and 

cetaceans within the project area are unlikely. In the case of a vessel-marine mammal 

collision, chronic and or acute sublethal effects may occur and stress or weaken individuals 

making them more susceptible to infection. Few lethal effects are expected from collisions 

with service vessels. Eni US Operating Co. Inc. will adhere to the information and 

guidelines set forth by Vessel Strike Avoidance and Injured/Dead Protected Species 

Reporting Notices to Lessees and Operators (BSEE; NTL 2012-JOINT-G01). 

Oil spills may affect cetaceans. Oil spills may potentially cause sublethal effects and death 

to marine mammals. Additionally, oil spill response activities may increase vessel traffic in 

the area, adding to changes in marine mammal behavior and distribution. The effect of oil 

dispersants on marine mammals is highly debated, causing results to be inconclusive. 

While an oil spill is improbable, adverse impacts to marine mammals are possible. Oil spill 

response planning and the habitat protection requirements of the Oil Pollution Act of 1990 

(Environmental Protection Agency [EPA]) should mitigate these threats. Eni US Operating 

Co. Inc.’s Spill Response Plan will cover activities proposed in this DOCD. 

The net result of any disturbance depends on the numbers of cetaceans affected, the 

ecological importance of the disturbed area(s), environmental and biological parameters 

influencing an animal’s sensitivity to disturbance and stress, and various other factors 

(Geraci and St. Aubin 1980). 

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

shore for treatment or disposal) from the proposed activities that could impact marine 

mammals. 

 
EIA – GC298 

MAY 2014 

8. Sea Turtles

Potential IPFs that could cause impacts to sea turtles from the proposed activities of this 

DOCD include emissions, effluents, discarded trash and debris, and accidents. 

Endangered or threatened sea turtle species that occur in the Gulf of Mexico are Kemp’s 

Ridley Turtle (Lepidochelys kempii), Green Turtle (Chelonia mydas), Hawksbill Turtle 

(Eretmochelys imbricate), Leatherback Turtle (Demochelys coriacea), and Loggerhead 

Turtle (Caretta caretta) (www.fws.gov, last accessed April 2013). 

Emissions: Brightly lit platforms and noise from drilling activities may affect sea turtle 

behavior temporarily and without lethal effects. 

Effluents: Contaminants in waste discharge and drilling muds might indirectly affect sea 

turtles via food-chain bioaccumulation, but there is uncertainty concerning the possible 

direct and indirect effects. Chronic sublethal stressors (e.g. stress) resulting in persistent 

physiological or behavioral changes and/or avoidance of impacted areas may cause 

declines in fecundity and survival of progeny resulting in population declines; however, such 

effects on sea turtles are not expected. 

Discarded Trash and Debris: Both entanglement in and digestion of debris have caused 

the death or serious injury of sea turtles (Schuyler et al. 2012). The limited amount of 

marine debris, if any, resulting from the proposed activities is not expected to substantially 

harm sea turtles. Eni US Operating Co. Inc. will adhere to the information and guidelines 

set forth by the Marine Trash and Debris Awareness and Elimination Notice to Lessees and 

Operators (NTL 2012-BSEE-G01). 

Accidents: Collisions between OCS vessels and sea turtles within the project area are 

unlikely. In the case of a vessel-sea turtle collision, chronic and or acute sublethal effects 

may occur and stress or weaken individuals making them more susceptible to infection. 

Few lethal effects are expected from collisions with service vessels. Eni US Operating Co. 

Inc. will adhere to the information and guidelines set forth by Vessel Strike Avoidance and 

Injured/Dead Protected Species Reporting Notices to Lessees and Operators (BSEE; NTL 

2012-JOINT-G01). 

In the unlikely event of an accidental surface or subsurface oil spill, sea turtles could be 

adversely impacted. Oil spills and oil spill response activities are potential threats that could 

have lethal effects on turtles. Contact with oil, consumption of oil particles, and oilcontaminated prey could seriously affect individual sea turtles. Oil spill response planning 

and the habitat protection requirements of the Oil Pollution Act of 1990 (EPA) should 

mitigate these threats. However, in the unlikely event of an accident, adverse impacts to 

sea turtles are possible. Eni US Operating Co. Inc.’s Spill Response Plan will cover 

activities proposed in this DOCD. 

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

delivered to shore for treatment or disposal) from the proposed activities that could impact 

sea turtles. 
EIA – GC298 

MAY 2014 

9. Air Quality

Air emissions—particulates, sulfur oxides, nitrogen oxides, volatile organic compounds and 

carbon monoxide, and other compounds have been estimated for the proposed activities 

and were determined to be below the BOEM exemption levels (www.boem.gov, last 

accessed April 2013). Accidents and blowouts may release polycyclic aromatic 

hydrocarbons and other chemicals, potentially causing the discharge of air pollutants. There 

would be a limited degree of air quality degradation in the immediate vicinity of the proposed 

activities; however, the emissions associated with the proposed activities are not projected 

to have significant effects on onshore air quality. Atmospheric conditions, emission height, 

emission rates, and the distance to shore are expected to contribute to dilution and 

dispersion of pollutants near the emission source, if pollutants are released. 

There are no other IPFs (including effluents, physical disturbance of the seafloor, wastes 

carried to shore for treatment or disposal, and discarded trash and debris) from the 

proposed activities that may impact air quality. 

10. Shipwreck Sites

After review of IPFs (including physical disturbances to the seafloor) resulting from activities 

proposed in this DOCD, there will be no adverse impacts to known or potential shipwreck 

sites. 

There are no shipwrecks within the Area of Potential Effect (APE). The “Deep Tow Survey, 

Allegheny Prospect, Blocks 297 & 298, Green Canyon Area”, Job No. 14-021-11,(Tesla 

Offshore, LLC), reported a total of 24 sonar targets throughout the surveyed area. Most of 

the targets are interpreted as isolated instances of modern debris. The single shipwreck, 

located in the adjacent Block 297 has been recommended for avoidance by a distance of 

500 feet. Provided that the avoidance zones surrounding these targets are adhered to, 

construction activities should not impact this site. 

There are no other IPFs (including emissions, effluents, wastes sent to shore for treatment 

or disposal, accidents, and discarded trash and debris) from the proposed activities that may 

impact shipwreck sites. 

11. Pre-historic Archaeological Sites

Green Canyon Area, Block 298, Well No. 7 is located in an area of high-probability for 

prehistoric and archaeological sites as identified in the BSEE NTL Archaeological Survey 

and Report Requirements (BSEE; NTL 2011-Joint-G01; Coastal Environments Inc. [CEI], 

1977). After review of impact-producing factors (including physical disturbances to the 

seafloor) resulting from activities proposed in this DOCD, there will be no adverse impacts to 

known or potential shipwreck sites. 

 
EIA – GC298 

MAY 2014 

Please refer to the “Deep Tow Survey, Blocks 297 & 298, Green Canyon Area, Gulf of 

Mexico. Job No. 14-021-11, April 2014 (Tesla Offshore, LLC). Water depths in the survey 

area exceed depths in which preserved prehistoric landforms are likely to occur; therefore, 

the assessment only addresses historic shipwrecks. If Eni US Operating Co. Inc. observes 

man-made debris indicating a shipwreck or archaeological site during lease development 

activities, Eni US Operating Co. Inc. will cease operations and immediately contact the 

BOEM Regional Supervisor of Leasing and Environment. 

Vicinity of Offshore Location 

1. Essential Fish Habitat

Potential IPFs affecting essential fish habitat from the proposed activities of this DOCD 

include physical disturbances to the seafloor, effluents, and accidents. 

Physical disturbance to the seafloor: The live bottom low relief stipulation, the live 

bottom pinnacle trend stipulation, and the Eastern Gulf live bottoms stipulation (BOEM, NTL 

2009-G39) prevents most of the potential impacts on live-bottom communities and essential 

fish habitat from bottom disturbing activities (anchoring, structure emplacement, and 

removal). 

Effluents: The live bottom low relief stipulation, the live bottom pinnacle trend stipulation, 

and the Eastern Gulf live bottoms stipulation prevents most of the potential impacts on livebottom communities and essential fish habitat 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 National Pollutant 

Discharge Elimination System (NPDES; EPA 1972) permit, minimizing significant biological 

or ecological effects. Operational discharges are not expected to cause significant adverse 

impacts to essential fish habitat. 

Accidents: In the unlikely event of an accidental surface or subsurface oil spill, the 

potential exists for detrimental effects to essential fish habitat. The following discussion of 

potential impacts to marine mammals is summarized from the Final Environmental Impact 

Statement (USDOI, MMS, 2002). Should a spill occur in the area of adult finfish or shellfish, 

the effects will likely be sublethal and the extent of the damage would be dependent on the 

ability of the adult fishes and shellfishes to avoid a spill, to metabolize polycyclic aromatic 

hydrocarbons, and to excrete both metabolites and parent compounds. In the unlikely event 

of an accident, adverse impacts to essential fish habitats are possible. Eni US Operating 

Co. Inc.’s Spill Response Plan will cover activities proposed in this DOCD. 

There are no other IPFs (including emissions, wastes sent to shore for treatment or 

disposal, and discarded trash and debris) from the proposed activities that will impact 

essential fish habitat. 

 
EIA – GC298 

MAY 2014 

2. Marine & Pelagic Birds 

Potential IPFs that may impact marine and pelagic birds from the proposed activities of this 

DOCD include emissions, accidents, and discarded trash and debris. 

Emissions: Emissions of pollutants into the atmosphere from the proposed activities are 

below concentrations estimated to cause harm to marine and pelagic birds (www.boem.gov, 

last accessed April 2013). 

Accidents: Oil spills pose the greatest potential impacts to marine birds. Heavy oiling of 

birds generally results in mortality. If physical oiling of birds occurs, some degree of both 

acute and chronic physiological stress associated with direct and secondary uptake of oil is 

expected. Lightly oiled birds can sustain tissues and organ damage from oil ingested or 

inhaled. Stress and shock enhance the effects of exposure and poisoning. Low levels of oil 

may stress birds by interfering with food detection, feeding impulses, predator avoidance, 

territory definition, homing of migratory species, susceptibility to physiological disorders, 

disease resistance, growth rates, reproduction, and respiration. Reproductive success is 

potentially affected with oil exposure. Indirect effects occur by disrupting nesting habitat and 

displacement of individuals, breeding pairs, or populations to less favorable habitats. 

Dispersant used in spill cleanup activity may have toxic effects similar to oil. 

Green Canyon Area, Block 298, Well No. 7 is located approximately 96 miles from the coast 

of Terrebonne Parish, Louisiana. Because of the distance from shore and the available oil 

spill response capabilities, no adverse impacts to the marine and pelagic bird population are 

anticipated as a result of the proposed activities. In the unlikely event of an accident, 

adverse impacts to marine and pelagic birds are possible. Eni US Operating Co. Inc.’s Spill 

Response Plan will cover activities proposed in this DOCD. 

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. The limited amount of marine debris, if any, resulting from the 

proposed activities is not expected to substantially harm marine and pelagic birds. Eni US 

Operating Co. Inc. will adhere to the information and guidelines set forth by the Marine 

Trash and Debris Awareness and Elimination Notice to Lessees and Operators (NTL 2012-

BSEE-G01). 

The majority of effects on endangered/threatened and non-endangered/non-threatened 

marine birds are expected to be sublethal: behavioral effects, sublethal exposure to or 

intake of OCS-related contaminants or discharge debris, temporary disturbance, and 

displacement of localized groups from impacted habitats. Chronic sublethal stress, 

however, is often undetectable in birds. As a result of stress, individuals may become weak, 

facilitating infection and disease; then migratory species may not have the strength to reach 

their destination. No significant habitat impacts are expected to occur directly from routine 

activities resulting from proposed actions under this DOCD. 

There are no other IPFs (including physical disturbance to the seafloor, effluents, and 

wastes sent to shore for treatment or disposal) from the proposed activities that could impact 

marine and pelagic birds. 
EIA – GC298 

MAY 2014 

3. Public Health & Safety 

After review of impact-producing factors (including an accidental H2S release) resulting from 

activities proposed in this DOCD, there is no potential for accidental release of a dangerous 

substance such as H2S gases. As stated in the H2S Information Section of the Plan, there is 

sufficient evidence from the drilling/production of previous wells to deem the proposed 

activity area as an area that is “H2S absent.” 

Coastal and Onshore 

1. Beaches

Potential IPFs that could cause impacts to beaches from the proposed activities of this 

DOCD include accidents and discarded trash and debris. 

Accidents: Green Canyon Area, Block 298, Well No. 7 is located approximately 96 miles 

from the coast of Terrebonne Parish, Louisiana. An accidental oil spill from the proposed 

activities would have a -/1/2 percent chance (based on 3, 10, or 30 days from the date of the 

spill) of causing impacts to the beaches at the coast line of Terrebonne Parish, Louisiana; a 

-/ -/ 1 percent (based on 3, 10, or 30 days from the date of the spill) of causing impacts to 

the beaches at the coast line of Lafourche Parish, Louisiana; and a -/ 1/ 4 chance (based on 

3, 10, or 30 days from the date of the spill) of causing impacts to the beaches at the coast 

line of Plaquemines Parish, Louisiana. Because of the distance from shore of the proposed 

activities and the available oil spill response capabilities, no adverse impacts to beaches are 

anticipated. In the unlikely event of an accident, adverse impacts to beaches are possible. 

Eni US Operating Co. Inc.’s Spill Response Plan will cover activities proposed in this DOCD. 

Discarded trash and debris: Trash on the beach is recognized as a major threat to the 

enjoyment and use of beaches. The limited amount of marine debris, if any, resulting from 

the proposed activities is not expected to significantly affect beaches. Eni US Operating Co. 

Inc. will adhere to the information and guidelines set forth by the Marine Trash and Debris 

Awareness and Elimination Notice to Lessees and Operators (BSEE; NTL 2012-BSEEG01). 

There are no other IPFs (including physical disturbance to the seafloor, effluents, emissions, 

and wastes sent to shore for treatment or disposal) from the proposed activities that could 

impact beaches. 

2. Wetlands

Potential IPFs that could cause deleterious effects to wetlands from the proposed activities 

of this DOCD include accidents. 

Accidents: : Green Canyon Area, Block 298, Well No. 7 is located approximately 96 miles 

from the coast of Terrebonne Parish, Louisiana. An accidental oil spill from the proposed 

activities would have a -/1/2 percent chance (based on 3, 10, or 30 days from the date of the 

spill) of causing impacts to the wetlands at the coast line of Terrebonne Parish, Louisiana; a 

-/ -/ 1 percent (based on 3, 10, or 30 days from the date of the spill) of affecting wetlands at 

the coast line of Lafourche Parish, Louisiana; and a -/ 1/ 4 chance (based on 3, 10, or 30 

days from the date of the spill) affecting wetlands at the coast line of Plaquemines Parish, 
EIA – GC298 

MAY 2014 

Louisiana. Because of the distance from shore of the proposed activities and the available 

oil spill response capabilities, no adverse impacts to the wetlands are anticipated. However, 

in the unlikely event of an accident, adverse effects to wetlands are possible. Eni US 

Operating Co. Inc.’s Spill Response Plan will cover activities proposed in this DOCD. 

There are no other IPFs (including physical disturbance to the seafloor, effluents, emissions, 

wastes sent to shore for treatment or disposal, and discarded trash and debris) from the 

proposed activities that could impact wetlands. 

3. Shore & Coastal Nesting Birds

Potential IPFs that could affect shore and coastal nesting bird species from the proposed 

activities of this DOCD include accidents and discarded trash and debris. 

Accidents: Oil spills pose the greatest potential impacts to shore birds and coastal nesting 

birds. Heavy oiling of birds generally results in mortality. If physical oiling of birds occurs, 

some degree of both acute and chronic physiological stress associated with direct and 

secondary uptake of oil is expected. Lightly oiled birds can sustain tissues and organ 

damage from oil ingested or inhaled. Stress and shock enhance the effects of exposure and 

poisoning. Low levels of oil may stress birds by interfering with food detection, feeding 

impulses, predator avoidance, territory definition, homing of migratory species, susceptibility 

to physiological disorders, disease resistance, growth rates, reproduction, and respiration. 

Reproductive success is potentially affected with oil exposure. Indirect effects occur by 

disrupting nesting habitat and displacement of individuals, breeding pairs, or populations to 

less favorable habitats. Dispersant used in spill cleanup activity may have toxic effects 

similar to oil. No significant habitat impacts are expected to occur directly from routine 

activities resulting from a proposed action. Secondary impacts to coastal habitats will occur 

over the long-term and may ultimately displace species from traditional sites to alternative 

sites. In the unlikely event of an accident, adverse impacts to marine and pelagic birds are 

possible. Eni US Operating Co. Inc.’s Spill Response Plan will cover activities proposed in 

DOCD. 

Green Canyon Area, Block 298, Well No. 7 is located approximately 96 miles from the coast 

of Terrebonne Parish, Louisiana. An accidental oil spill from the proposed activities would 

have a -/1/2 percent chance (based on 3, 10, or 30 days from the date of the spill) of 

causing impacts to the shore birds and coastal nesting birds that occur onshore in 

Terrebonne Parish, Louisiana; a -/ -/ 1 percent chance (based on 3, 10, or 30 days from the 

date of the spill) of causing impacts to the shore birds and coastal nesting birds that occur 

onshore in Lafourche Parish, Louisiana; and a -/ 1/ 4 chance (based on 3, 10, or 30 days 

from the date of the spill) of causing impacts to shore birds and coastal nesting birds that 

occur onshore in Plaquemines Parish, Louisiana. Because of the distance from shore of the 

proposed activities and the available oil spill response capabilities, no adverse impacts to 

the shore birds and coastal nesting birds are anticipated. In the unlikely event of an 

accident, adverse impacts to shore and coastal nesting birds are possible. Eni US 

Operating Co. Inc.’s Spill Response Plan will cover activities proposed in this DOCD. 

Discarded trash and debris: If present, shore birds and coastal nesting birds may become 

entangled and snared in discarded trash and debris or ingest small plastic debris causing 

permanent injuries and death. The limited amount of marine debris, if any, resulting from the 
EIA – GC298 

MAY 2014 

proposed activities is not expected to cause significant harm marine and pelagic birds Eni 

US Operating Co. Inc. will adhere to the information and guidelines set forth by the Marine 

Trash and Debris Awareness and Elimination Notice to Lessees and Operators (NTL 2012-

BSEE-G01). 

There are no other IPFs (including physical disturbance to the seafloor, effluents, emissions, 

and wastes sent to shore for treatment or disposal) from the proposed activities that could 

impact shore and coastal nesting birds. 

4. Coastal Wildlife Refuges

Potential IPFs that could cause impacts to coastal wildlife refuges from the proposed 

activities of this DOCD include accidents. 

Accidents: Green Canyon Area, Block 298, Well No. 7 is located 96 miles from the coast of 

Terrebonne Parish, Louisiana. An accidental oil spill from the proposed activities would 

have a -/1/2 percent chance (based on 3, 10, or 30 days from the date of the spill) of 

causing impacts to the coastal wildlife refuges that occur onshore in Terrebonne Parish, 

Louisiana; a -/-/1 percent chance (based on 3, 10, or 30 days from the date of the spill) of 

causing impacts to the coastal wildlife refuges that occur onshore in Lafourche Parish, 

Louisiana; and a -/1/4 percent chance (based on 3, 10, or 30 days from the date of the spill) 

of causing impacts to the coastal wildlife refuges that occur onshore in Plaquemines Parish, 

Louisiana. Because of the distance from this refuge of the proposed activities and the 

available oil spill response capabilities, no adverse impacts to coastal wildlife refuges are 

anticipated. In the unlikely event of an accident, adverse impacts to coastal wildlife refuges 

are possible. Eni US Operating Co. Inc.’s Spill Response Plan will cover activities proposed 

in this DOCD. 

 

There are no other IPFs (including physical disturbance to the seafloor, effluents, emissions, 

wastes sent to shore for treatment or disposal, and discarded trash and debris) from the 

proposed activities that could impact coastal wildlife refuges. 

In regards to Louisiana resources, an accidental oil spill from the proposed activities would 

have the following probabilities (based on 3, 10, or 30 days from the date of the spill) of 

causing impacts to coastal wildlife refuges: 

 State of Louisiana WMA and Game Preserve in Vermilion Parish ( -/ -/ 2) 

 Paul J. Rainey Wildlife Sanctuary in Vermilion Parish ( -/ -/ 2) 

 Rockefeller State Wildlife Refuge in Vermilion Parish ( -/ -/ 2) Cameron Parish (-/ -/ 5) 

 Atchafalaya WMA in Terrebonne Parish ( -/ 1/2) 

 Breton National Wildlife Refuge in Terrebonne Parish ( -/1/2) 

 Pass a Loutre WMA in Terrebonne Parish ( -/1/2) 

 Delta National Wildlife Refuge in Terrebonne Parish (-/1/2) 

 Wisner WMA in Lafourche Parish ( -/ -/ 1) 

5. Wilderness Areas

Potential IPF’s that could cause impacts to wilderness areas from the proposed activities of 

this DOCD include accidents. 
EIA – GC298 

MAY 2014 

Accidents: Green Canyon Area, Block 298, Well No. 7 is located approximately 96 miles 

from the coast of Terrebonne Parish, Louisiana. Due to the distance from shore and the 

available oil spill response capabilities, no adverse impacts to wilderness areas are 

anticipated as a result of the proposed activities. However, in the unlikely event of an 

accident, adverse impacts to wilderness areas are possible. Eni US Operating Co. Inc.’s 

Spill Response Plan will cover activities proposed in this DOCD. 

Texas has five areas designated by Congress as Wilderness Areas, namely the Big Slough 

Wilderness Area, Indian Mounds Wilderness Area, Little Lake Creek Wilderness Area, 

Turkey Hill Wilderness Area, and the Upland Island Wilderness Area, none of which are 

located along the coastal region of Texas; and the only wilderness area located along the 

coastal region of Louisiana is the Breton Wilderness Area, located on the eastern side of the 

Mississippi River, approximately 140 miles from Green Canyon Area, Block 298. Due to the 

distance from shore and the available oil spill response capabilities, no adverse impacts to 

wilderness areas are anticipated as a result of the proposed activities. 

There are no other IPF’s (including physical disturbance to the seafloor, effluents, 

emissions, wastes sent to shore for treatment or disposal, and discarded trash and debris) 

from the proposed activities that could impact wilderness areas. 

(C) IMPACTS ON PROPOSED ACTIVITIES 

A Wellsite Clearance Letter was prepared for the proposed surface location. The surface 

location was evaluated for any seafloor and subsurface geological and manmade features 

and conditions that may adversely affect operations. Referencing Fugro GeoConsulting, 

Inc., Wellsite Clearance Letter, Report No. 27.2014-2706-GC298-7, dated April 27, 2014; 

infrastructure is located within 2,000 ft of the proposed wellsite. Eni pipeline segments 

#13413, #16150, and #16149 are located 1,275 ft west-northwest, 1,300 ft east, and 1,360 ft 

west-southwest, respectively, from the proposed wellsite. 

While no impacts are expected from the proposed activities on site-specific environmental 

conditions it is recommended that an ROV be used to inspect the seafloor at the proposed 

wellsite immediately before spud-in to confirm that no seafloor obstructions have appeared 

since the archaeological survey data was acquired. 

 

(D) ENVIRONMENTAL HAZARDS 

During the hurricane season—June through November of each year—the Gulf of Mexico is 

potentially impacted by an average of ten tropical storms (39-73 mph winds), of which six 

may become hurricanes (>74 mph winds). Because of the proposed location in the Gulf of 

Mexico, Green Canyon Area, Block 298, Well No. 7 may experience hurricane and tropical 

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 material (including polycyclic aromatic hydrocarbons). Additionally, the 
EIA – GC298 

MAY 2014 

displacement of equipment may disrupt the local benthic habitat and pose a threat to local 

species. 

The following preventative measures included in this plan may be implemented to mitigate 

these impacts: 

 

Drilling and Completion 

 Secure well 

 Secure drilling rig/platform 

 Evacuate personnel 

Alternatives

No alternatives to the proposed activities were considered to reduce environmental 

impacts. 

1. Mitigation Measures

No mitigation measures other than those required by regulation will be employed to 

avoid, diminish, or eliminated potential impacts on environmental resources. 

2. 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. 

3. Preparer 

Wendy Fiaschetti 

Regulatory Specialist 

wfiaschetti@fugro.com 

337-268-3152 

John Chance Land Surveys, Inc. 

200 Dulles Drive 

Lafayette, Louisiana 70506 

4. References

NOAA. National Oceanic and Atmospheric Association. 2010. Deep sea subsurface oil 

assessment. NOAA, National Incident Command, Unity of Effort. www.noaa.gov, last 

accessed 19 September 2012. 

Schmahl GP, Hickerson EL, Nuttall MF. 2012. Science-based design of coral protected 

areas in the Gulf of Mexico. Proceedings of the 12th Internation Coral Reef 

Symposium. 9-12 July 2012. Cairns, Australia. 

Schuyler Q, Hardesty BD, Wilcox C, Townsend K. 2012. To eat or not to eat? Debris 

selectivity by marine turtles. PLoS ONE 7:1-9. 

USDOI. U.S. Department of the Interior, Fish and Wildlife Service Endangered and 

threatened species of the southeastern United States. Region IV, Atlanta, Georgia. 

USDOI, MMS. U.S. Department of the Interior, Minerals Management Service. 2002. 

Gulf of Mexico OCS oil and gas lease sales: 2003-2007; Central Planning Area 

Sales 185, 190, 194, and 201; Western Planning Area Sales 187, 192, 196, and 

200—final environmental impact statement; Volumes I and II. U.S. Dept. of the 

Interior, Mineral Management Service, Gulf of Mexico OCS Region, New Orleans, 
EIA – GC298 

MAY 2014 

LA. OCS EIS/EA MMS 2002-052. 

Williams R, Ashe E, O’Hara PD. 2011. Marine mammals and debris in coastal waters of 

British Columbia, Canada. Marine Pollution Bulletin 62:1303-1316. 

Wilson B, Batty RS, Daunt F, Carter C. 2007. Collision risks between marine renewable 

energy devices and mammals, fish and diving birds. Report to the Scottish 

Executive. Scottish Association for Marine Science, Oban, Scotland, PA37 1QA. 

Wright AJ and Weilgart L. 2011. Assessing cumulative impacts of underwater noise with 

other stressors on marine mammals. Acoustical Society of America 129:2394-2394. 

Fugro GeoConsulting, Inc. Wellsite Clearance Letter, Proposed Wellsite GC 298, Well 

No. 007, Green Canyon Area, Block 298, Gulf of Mexico. Report No. 27-2014-2706-

GC298-7, Apirl 27, 2014. 

Fugro GeoConsulting, Inc., Shallow Hazard Assessment, Allegheny Prospect, Block 298 

(OCS-G-08010), Green Canyon Area, Gulf of Mexico. Report No. 27.2014-2706, 

March 24, 2014. 

Tesla Offshore, LLC, Deep Tow Survey, Allegheny Prospect, Blocks 297 & 298, Green 

Canyon Area (OCS-G-08876 & 08010), Gulf of Mexico. Job No. 14-021-11, April 

2014. 
Eni US Operating Co. Inc. Page 25

Supplemental DOCD May 19, 2014 

Green Canyon Block 298 (OCS-G 08010) Public Information

SECTION R 

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 DOCD as well as any discussions of the target objectives, geologic or geophysical data, and any interpreted 

geology. 

(b) Bibliography 

Not applicable.