UNITED STATES GOVERNMENT MEMORANDUM

To: Public Information (MS 5030)

Plans Section, Office of Field Operations (MS 5231)

Public Information copy of Exploration Plan
Control # - S-07587
Type - Supplemental Exploration Plan
Lease(s) - OCS-G31938 Block - 51 Walker Ridge Area
Operator - Anadarko Petroleum Corporation
Wells CC and DD

Not Found

Attached is a copy of the subject plan for public comments on issues that should be addressed in an Environmental Assessment.

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

Michelle Griffitt Plan Coordinator Description -
Rig Type - Subject: From: November 20, 2012

### SUPPLEMENTAL EXPLORATION PLAN (S-7587)

ANADARKO PETROLEUM CORPORATION

WALKER RIDGE BLOCK 51 OCS-G 31938

PUBLIC COPY

RECORD OF CHANGE LOG

Submission Type Date Sent to BOEM Summary of Submission Page Numbers Initial 09/18/2012 Supplemental EP submission. All Amendment 10/05/2012 Provided wellbore schematic for proposed Location CC. (Proprietary data not included within Public Copy.) N/A

Final Copy of Plan 11/06/2012 Complete EP submittal. All

Add Record of Change Log 11/06/2012 Add record of change log. 1

# PUBLIC

SUPPLEMENTAL EXPLORATION PLAN

WALKER RIDGE BLOCK 51 OCS-G 31938

OFFSHORE, LOUISIANA

Anadarko Petroleum Corporation 1201 Lake Robbins Drive The Woodlands, Texas 77380 Contact: Bridget O’Farrell Bridget.OFarrell-Villarreal@anadarko.com (832) 636-1694

1 – Hard Copy Confidential 1 – CD Confidential 1 – Hard Copy Public Information 1 – CDs Public Information



### September 2012

## SUPPLEMENTAL EXPLORATION PLAN LEASE OCS-G 31938 Walker Ridge Block 51

A. Plan Contents

B. General Information

C. Geological, Geophysical

D. Hydrogen Sulfide Information

E. Biological, Physical and Socioeconomic Information

F. Wastes and Discharge Information

G. Air Emissions Information

H. Oil Spill Information

I. Environmental Monitoring Information

J. Lease Stipulations

K. Support Vessels and Aircraft Information

L. Onshore Support Facilities Information

M. Coastal Zone Management Act Information

N. Environmental Impact Analysis

O. Administrative Information

## A PLAN CONTENTS

(a) Plan Information Form

Under this Supplemental Exploration Plan (EP) , Anadarko Petroleum Corporation (Anadarko) proposes to drill and complete two wells in Walker Ridge Bloc k 51, Locations “CC” and “DD”. Both wells will have their surface and bottom- hole locations in Walker Ridge Block 51. The wells will be drilled using a drillship, dynamica lly positioned (DP) semi-submersible drilling rig, or a semi-submersible drilling rig. It is anticipate d that anchors will not be utilized at this time, however, an anchor radius has be en provided for reference if the decision is made to utilize a semi-submersible drilling unit in the future. Drilling and completion operations for all well locations will utilize a Subsea BOP stack. OCS Plan Informati on Form BOEM-137 is enclosed

as Attachment A-1.

(b) Location

Enclosed as Attachment A-2 is a well location plat at a scale of 1 inch = 2000 feet that depicts the surface location and water depth of the proposed well.
(c) Safety and Pollution Prevention Features

Safety features on the drilling unit will include well control, pollution prevention, safe welding procedures, and blowout prevention equipment as described in Title 30 CFR Part 250, Subparts C, D, E, G and O; and as fu rther clarified by BOEM/BSEE Notices to Lessees, and applicable regulations of the Environmenta l Protection Agency and the U.S. Coast Guard. The appropriate life rafts, life jackets, ring buoys, etc., as prescr ibed by the U.S. Coast Guard, will be maintained on the facility at all times.

### (d) Storage Tanks and Production Vessels The Walker Ridge Block 51 well locations will be dr illed with a drillship, DP semi-submersible drilling rig, or a semi-s ubmersible drilling rig.

Type of Facility Type of Storage Tank Tank Capacity Number of Tanks Total Capacity Fluid Gravity

(API) Total Capacity of all Tanks for

Rig Type Drillship Fuel Oil Storage Tank 16,564 bbls 1 16,564 bbls No. 2 Diesel 6 tanks total= 36,595.9 bbls

Fuel Oil Storage Tank 16,685.5 bbls 1 16,685.5 bbls No. 2 Diesel

Fuel Oil Settling Tanks 836.6 bbls 2 1,673.2 bbls No. 2 Diesel

Fuel Oil Day Tanks 836.6 bbls 2 1,673.2 bbls No. 2 Diesel

DP Semi-submersible Fuel Oil Hull Tanks 4,541 bbls 2 9,082 bbls No. 2 Diesel 7 tanks total= 16,689 bbls

Fuel Oil Hull Tanks 3,392 bbls 2 6,784 bbls No. 2 Diesel

Fuel Oil Deck Day Tank 629 bbls 1 629 bbls No. 2 Diesel

Fuel Oil Deck Settling Tank 164 bbls 1 164 bbls No. 2 Diesel

Fuel Oil Emergency Generator 30 bbls 1 30 bbls No. 2 Diesel

Semi-submersible Fuel Oil Storage Tanks 3,331.5 bbls 2 6,663 bbls No. 2 Diesel 4 tanks total= 6,900.7 bbls

Fuel Oil Day Tank 214.8 bbls 1 214.8 bbls No. 2 Diesel

Fuel Oil Overflow Tank 22.9 bbls 1 22.9 bbls No. 2 Diesel

### (e) Pollution Prevention Measures

The drilling rig utilized for these operations will comply with all applicable regulations regarding pollution prevention and control. The rig has a Shipboard Oil Pollution Emergency Plan (SOPEP), which is reviewed and approved annually by the American Bureau of Shipping (ABS). The SOPEP is provided to assist employees in d ealing with an unexpected discharge of oil. Its primary purpose is to set in motion the necessary actions to stop or minimi ze the discharge of oil and to mitigate its effects. Effective planning en sures that the necessary actions are taken in a structured, logical, and timely manner.

Pollution prevention measures includ e installation of curbs, gutters, drip pans, and drains on deck areas to collect all contaminants and debris. Most deck drains and some of the joints at the edge of the rig floor go overboard or into the moon pool, respectively. To prevent ocean discharge from the drains there is a dedicated drip pan un der the rotary table. The pipe racks, mud pump room, sack store, and drill floor drains go to a holding tank, which is se rved by a dedicated oily water separator. The well test area, engine room , and other major machinery spaces drains all go to slops tanks, which are served by a large general-serv ice, oily water separa tor. The containment devices are temporary. They are not meant for perm anent storage of waste. On the rare occasion that they contain wastes, they are pumped, moppe d, or cleaned within a short period of time. The chances of damage to a containment structur e during such time as it contains wastes are exceedingly small.

(f) Additional Pollution Prevention Measures

No additional measures are proposed under this plan. The activities proposed in this plan are not located offshore Florida.

### (g) Description of Previously Approved Lease Activities

Anadarko was granted approval to drill and comple te the following locations in Walker Ridge Block 51. The Initial EP was filed and a pproved under Anadarko E&P Company LP for Locations “A” and “B” under Plan Control No: N-9291. Anadarko Pe troleum Corporation filed a Supplemental Exploration Plan for additional we ll locations in Walker Ridge Block 51 for Well Locations “C” and “D” which were approved in Plan Control No: S-7513.

The proposed locations “CC” & “DD” are repla cement locations for the approved EP locations “C” & “D” from Plan Control No: S-7513. In ear ly September 2012, the Walker Ridge Block 51 #001 wellbore , OCS-G31938, which was drilled at the approved “C” location, was junked and abandoned before reaching objective section, due to a mechanical failure. A replacement well was spud at the approved “D” location (back -up location), which is approximately 1,000 ' due west of “C”. Both the “CC” and “DD” locations are positioned 100 ' due west of the “C” and “D” locations, respectively, with the primary goal of having additional back-up locations in the event of further mechanical failure.

Control # Plan Type/Approval WR 51 Well Location Status of Well Location

N-9291 Initial EP Approved 3/30/2009 A B Open location for future drill site N/A

S-7513 Supplemental EP Approved 3/7/2012 C D Drilled as Well #001 Drilling as Well #002 P&A’d, 9/2012 Currently drillingMMS FORM MMS-137 (December 2008 - Supersedes all previous edi tions of form MMS-137 which may not be used.) Page 1 of 3 U.S. Department of the Interior Minerals Management Service 

### OCS PLAN INFORMATION FORM OMB Control Number: 1010-0051 OMB Approval Expires: 12/31/2011

General Information Type of OCS Plan: x Exploration Plan (EP) Development Operations Coordination Document (DOCD)
Company Name: Anadarko Petroleum Corporation MMS Operator Number: 00981

Address: 1201 Lake Robbins Drive C ontact Person: Bridget O’Farrell
The Woodlands, TX 77380 Phone Number: (832) 636-1694

E-Mail Address: Bridget.OF arrell-Villarreal@anadarko.com
Lease(s): OCS-G 31938 Area: WR Block(s): 51 Project Name (If Applicable): Shenandoah
Objective(s): x Oil x Gas Sulphur Salt Onshore Base: Fourchon, LA Distance to Closest Land (Miles): 153 Description of Proposed Activi ties (Mark all that apply)

x Exploration drilling Development drilling

x Well completion Installation of production platform
Well test flaring (for more than 48 hours) Installation of production facilities
Installation of caisson or platform as well protecti on structure Installation of satellite structure

x Installation of subsea wellheads and/or manifolds Commence production
Installation of lease term pipelines Ot her (Specify and describe)
Have you submitted or do you plan to submit a Conser vation Information Document to accompany this plan? Yes x No
Do you propose to use new or unusual technology to conduct your activities Yes x No
Do you propose any facility that will serve as a host facility for deepwater subsea development? Yes x No
Do you propose any activities that may disturb an MMS-designated hi gh-probability archaeological area? Yes x No

Have all of the surface locations of your proposed activities been previ ously reviewed and approved by MMS? Yes x No Tentative Schedule of Proposed Activities
Proposed Activity Start Date End Date No. of Days
Drill and complete Location CC 2/12/2013 7/ 12/2013 150
Drill and complete Location DD 1/1/2014 5/ 31/2014 150

Description of Drilling Rig Description of Production Platform
Jackup x Drillship Caisson Tension leg platform
Gorilla Jackup Platform rig Well protector Compliant tower

x Semisubmersible Submersible Fixed platform Guyed tower

x DP Semisubmersible Other (Attach Description) Subsea manifold Floating production system
Drilling Rig Name (If Known): Spar Other (Attach Description) Description of Lease Term Pipelines
From (Facility/Area/Block) To (Facility/Area /Block) Diameter (Inches) Length (Feet)MMS FORM MMS-137 (December 2008 - Supersedes all previous edi tions of form MMS-137 which may not be used.) Page 2 of 3 OCS PLAN INFORMATION FORM (CONTINUED) Include one copy of this page for each proposed well/structure Proposed Well/Str ucture Location Well or Structure Name/Number (If renaming well or structure, reference previous name): CC Subsea Completion

Anchor Radius (if applicable) in feet: 12,000' (with 1,000' buffer)* Only if a semi-submersible rig is utilized x Yes No

Surface Location Bottom-Hole Location (For Wells)

Lease No. OCS-G 31938

Area Name Walker Ridge

Block No. 51

Blockline Departures (in feet) N/S Departure: 6,174' FNL N/S Departure: F L

E/W Departure: 2,616' FEL E/W Departure: F L

Lambert X-Y coordinates X: 2,104,104 X:

Y: 9,767,106' Y:

Latitude/ Longitude Latitude: 26.9093243 Latitude:

Longitude: 91.5767518 Longitude:

TVD (Feet): MD (Feet): Water Depth (Feet): 5,838'
Anchor Locations for Drilling Rig or Construction Barge (If anchor radius supplied above, not necessary)

Anchor Name or No. Area Block X Coordinate Y Coordinate Length of Anchor Chain on Seafloor

X = Y =

X = Y =

X = Y =

X = Y =

X = Y =

X = Y =

X = Y =

X = Y = Paperwork Reduction Act of 1995 Statement: The Paperwork Reduction Act of 1995 (44 U.S.C. Chapter 35) requires us to inform you that MMS collects this info rmation as part of an applicant’s Exploration Plan or Development Operations Coordination Document submitted for MMS approval. We use th e information to facilitate our review and data entry for OCS plans. We will protect proprietar y data according to the Freedom of Info rmation Act and 30 CFR 250.197. An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid Office of Management and Budget Control Number. The use of this form is voluntary. The public reporting burden for this form is included in the burden for preparing Exploration Plans and Development Operations Coordination Documents. We estimate that burden to average 600 hours per res ponse, or 640 with an accompanying EP (1,000 hours in AKOCSR), or 690 (1,700 in AKOCSR) with an accompanying DPP or DOCD, including the time for reviewing instructions, gathering and maintaining data, and comp leting and reviewing the forms associated with subpart B. Direct comments regarding the burden estimate or any other as pect of this form to the In formation Collection Clearance Officer, Mail Stop 5438, Minerals Management Service, 1849 C Street, NW., Washington, DC 20240.MMS FORM MMS-137 (December 2008 - Supersedes all previous edi tions of form MMS-137 which may not be used.) Page 3 of 3 OCS PLAN INFORMATION FORM (CONTINUED) Include one copy of this page for each proposed well/structure Proposed Well/Str ucture Location Well or Structure Name/Number (If renaming well or structure, reference previous name): DD Subsea Completion

Anchor Radius (if applicable) in feet: 12,000' (with 1,000' buffer)* Only if a semi-submersible rig is utilized x Yes No

Surface Location Bottom-Hole Location (For Wells)

Lease No. OCS-G 31938

Area Name Walker Ridge

Block No. 51

Blockline Departures (in feet) N/S Departure: 6,239' FNL N/S Departure: F L

E/W Departure: 3,641' FEL E/W Departure: F L

Lambert X-Y coordinates X: 2,103,279' X:

Y: 9,767,041' Y:

Latitude/ Longitude Latitude: 26.9091710 Latitude:

Longitude: 91.5792857 Longitude:

TVD (Feet): MD (Feet): Water Depth (Feet): 5,837'
Anchor Locations for Drilling Rig or Construction Barge (If anchor radius supplied above, not necessary)

Anchor Name or No. Area Block X Coordinate Y Coordinate Length of Anchor Chain on Seafloor

X = Y =

X = Y =

X = Y =

X = Y =

X = Y =

X = Y =

X = Y =

X = Y = Paperwork Reduction Act of 1995 Statement: The Paperwork Reduction Act of 1995 (44 U.S.C. Chapter 35) requires us to inform you that MMS collects this info rmation as part of an applicant’s Exploration Plan or Development Operations Coordination Document submitted for MMS approval. We use th e information to facilitate our review and data entry for OCS plans. We will protect proprietar y data according to the Freedom of Info rmation Act and 30 CFR 250.197. An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid Office of Management and Budget Control Number. The use of this form is voluntary. The public reporting burden for this form is included in the burden for preparing Exploration Plans and Development Operations Coordination Documents. We estimate that burden to average 600 hours per res ponse, or 640 with an accompanying EP (1,000 hours in AKOCSR), or 690 (1,700 in AKOCSR) with an accompanying DPP or DOCD, including the time for reviewing instructions, gathering and maintaining data, and comp leting and reviewing the forms associated with subpart B. Direct comments regarding the burden estimate or any other as pect of this form to the In formation Collection Clearance Officer, Mail Stop 5438, Minerals Management Service, 1849 C Street, NW., Washington, DC 20240.

## Walker Ridge Block 51 Anadarko SL WR 51 “CC” 2,616’ FEL 6,174’ FNL X = 2,104,104’ Y = 9,767,106’ LAT = 26.9093243 N LONG = 91.5767518 W

Anadarko SL WR 51 “DD” 3,641’ FEL 6,239’ FNL X = 2,103,279’ Y = 9,767,041’ LAT = 26.9091710 N LONG = 91.5792857 W 

## Walker Ridge Block 7

Walker Ridge Block 95 0 2,000

FEET



# Walker Ridge Block 51

OCS

‐ G

‐ 31938 

# Well Locations

### B GENERAL INFORMATION

(a) Applications and Permits

Prior to beginning exploration operations the following application(s) will be submitted for approval:

Application/Permit Issuing Agency Status Permit to Drill BSEE To be submitted

(b) Drilling Fluids

Type of Drilling Fluid Estimated Volume Per Well Water-based (16.0 ppg SSRiser Vis) for Pump and Dump 25,000 bbls per well

Synthetic-based (internal olef in, ester) 15,000 bbls per well Oil-based N/A

(c) Oils Characteristics

Oil will not be produced under this Supplementa l Exploration Plan. Therefore the oil(s) characteristics information is not required per NTL 2008-G04 2(d).

(d) New or Unusual Technology

Anadarko does not propose to use any new or u nusual technology to drill the wells proposed in this plan.

(e) Bonding Statement

The bond requirements for the activities and facili ties proposed in this EP are satisfied by an area-wide bond furnished and maintained accor ding to 30 CFR part 256, subpart I; NTL No. 2000-G16, “Guidelines for General Lease Surety Bonds,” and National NTL No. 2008-N07, “Supplemental Bond Procedures”.

(f) Oil Spill Financial Responsibility (OSFR)

Anadarko Petroleum Corporation (Company Number 00981) has demonstrated oil spill financial responsibility for the f acilities proposed in this EP according to 30 CFR Part 253, and NTL No. 2008-N05, “Guidelines for Oil Sp ill Financial Responsibility for Covered Facilities”.

### (g) Deepwater Well Control Statement

Anadarko Petroleum Corporation (Company Number 00981) has the financia l capability to drill a relief well and conduct other emergenc y well control operations if required.

(h) Blowout Scenario

Anadarko prepared this blowout scenario pursu ant to guidance provided in NTL No. 2010-N06. The previously approved Walker Ridge Block 51 #1 (Location “C”) well is addressed in this blowout scenario since it is the location with the highest potential worst case discharge (WCD) rate for Walker Ridge Block 51. A similar appro ach would be taken in the event of a blowout for the wells covered under th is plan. Based on NTL No. 2010-N06 guidance, the maximum hydrocarbon discharge for Walker Ridge Block 51 is calculated to be 80,000 bopd (approved under Plan Control No: S-7513).

Purpose This information provides a generic blowout scenario, additional information regarding any potential oil spill, the measures Anadarko Petr oleum will take to prevent a blowout, and if necessary, promptly respond to manage a blow out scenario if one occurs. The following information is pursuant with 30 CF R 250.213(g), 250.219, 250.250 and NTL No. 2010-N06.

Background This overview has been developed to document th e additional information requirements for EPs as requested by NTL No. 2010-N06.

Information Requirements:

Blowout Scenario

The Walker Ridge Block 51 #1 (Location “C”) e xploration well was to be drilled utilizing a MODU rig with a marine riser and sub-sea BOP. A typical casing program will be used including a wellhead system, conductor casing, su rface casing, intermediate casing, as well as two drilling liners to reach the planned total depth.

The blowout scenario assumes that a hydrocarbon influx occurs followed by a well control event from the objective sands. The sub-sea BOP an d marine riser subsequently fail followed by a blow out to the seabed. The worst cas e discharge (WCD) scenario assumes 8-1/2" open hole with a 9-3/8" drilling liner, an 11-7/8" drilling liner, and 14" x 13-5/8" intermediate casing string set as shown in the wellbore schematic.

### Estimated flow rate of the potential blow out:

Category Supplemental EP Type of Activity Exploration Drilling Facility Location (area/block) WR 51 Facility Designation Location “C” Distance to Nearest Shoreline (miles) 153 Uncontrolled blowout (volume per day) 80,000 bopd Type of Fluid(s) Crude oil API Gravity 26 °

a) Potential for the well to bridge over:

Discussions regarding geologic information ar e considered proprietary and have been omitted from this public copy of the EP.

b) Measures to enhance ability to conduct effect ive and early intervention in the event of a blowout:

The likelihood of surface intervention to prev ent, or stop, a blowout is high and is based on the following equipment specific to a capable MODU that will be contracted to do this drilling program:

 ROV Secondary BOP Control System: The BOP will be confirmed to have an ROV Intervention Panel and circuits that have the following attributes:

 Hot stab capable of closing one set of:

 Blind-Shear Rams

 Pipe Rams

 Unlatch the Lower Marine Riser Package

 Hot stab has been function tested in conjunction with the Stump Test and was tested at the same rate and pressure as the pump installed on the ROV used by the rig.

The panel can also be operated by an ROV from an independent supply boat in the event of a loss of rig scenario.

 Deadman / Autoshear function: Th e rig will be equipped with an automated sequence that closes the blind shear rams in the event of any of the following scenarios:

 Inadvertent disconnect of the LMRP

 Loss of both hydraulic pressure an d electrical supply from the surface BOP control system

No human interface is to be required once these systems are armed.

### c) Availability of a rig to drill a relief well:

As per the preliminary Mutual Aid agreements that are being worked between E&P Operators in the Gulf of Mexico, Anadarko will select from the best rig option available in the Gulf of Mexico fleet if and when it is required for relief well work.

As of September 18, 2012 there were 19 additi onal rigs in the Gulf of Mexico which would be capable of operating under the conditions associated with drilling a relief well for this prospect. A rig which could be used to drill a relief well is the Discoverer Inspiration which is a dynamically positioned drills hip capable of operating in the water depths, and drilling to th e total well depths, associated with a relief well for this prospect. The rig is currently under contract to Chev ron and is on location in Walker Ridge Block 677.

There are no nearby platforms from which to drill a relief well.

It is not feasible to dr ill a relief well from land.

d) Rig constraints:

A rig with a 15,000 psi BOP Stack and capable of drilling in 5,838' of water is required for any relief well operations.

e) Time taken to mobilize a rig and drill a relief well:

An estimated 7-21 days is required to suspend operations on a deepwater GOM well, mobilize to a relief well loca tion, and begin relief well drill ing operations. This estimate includes 0-14 days to suspend current opera tions on an existing well and acquire a contracted rig, and 7 days to mobilize to locat ion and be ready to spud a relief well. The estimated time to drill the relief well and perform kill operations is 150 days for an estimated total of 157-171 days from time of blowout to finish ing the relief well.

The time estimate provided for the plan well is inclusive of 'both' drilling 'and' completion operations. As a completion is no t typically part of relief well operations no time has been included for completion operations in the relief well es timate. In addition, information and learning from the drilling of the original well ma y provide opportunities to optimize drilling performance for relief we ll operations and thus reduce the required drilling time.

### f) Assumptions and calculations used in a pproved or proposed Oil Spill Response Plan:

Garden Banks Block 346, Regional Oil Spill Response Plan

 Petroleum Expert’s Prosper software was used for the nodal analysis. The WCD for the Garden Banks Block 346 #002 (Location A) is 321,108.

 The maximum total volume during a bl owout could potentially be 37,890,744 bbls assuming 118 days for the maximum duration of a blowout.

 The volume denoted in the Regional OSRP is higher than the NTL No. 2010-N06 (256,700 bopd) and BOEM (321,108 bopd) calcul ations approved under the Initial EP (Plan Control No.: N-9579). Anadarko elected to denote a higher volume (350,000 bbls) in the Regional OSRP for planning purposes to de monstrate equipment response capabilities per prev ious discussions w ith Rusty Wright.

Walker Ridge Block 51–Supplemen tal EP, Plan Control No: S-7513

 Nodal analysis was performed to calculate worst case discharge volumes. Input data and assumptions utilized for the analysis of the Walker Ridge 51 #1 (Location “C”) well, along with the respective outputs, we re included in Plan Control No: S-7513. The result being that at the seafloor, the estimated worst case discharge for the well is 80,000 bopd.

 The maximum total volume during a bl owout could potentially be 13,680,000 bopd assuming 171 days for the maximum durati on of a blowout, multiplied by the worst case daily uncontrolled bl owout volume of 80,000 bopd.

g) Measures taken to enhance the ability to prevent or reduce the likelihood of a blow-out

 Well design : Anadarko utilizes a systematic we ll design process for the planning and construction of a well operation. This pr ocess utilizes the depth of experience Anadarko possesses in the deepwater aren a and involves a multi-disciplinary team peer review of the well design, shallow h azards, and formation pressure hazards expected during the drilling pha se of the well. This process minimizes the potential for an unplanned well control event that coul d lead to a blowout. This process will also include Professional Engineer review and certification of the final casing design and cementing program.

A detailed pre-drill assessment of form ation pressure provided by Anadarko’s Geologic/Geophysical team, along with th ird party consultants, allows for development of a mud program that provi des an overbalanced mud weight for the safe drilling of the well. For an expl oration well this may also include taking formation pressures to confirm the act ual formation pressure during the well construction process and minimize the risk of an unplanned well control event.

### The well construction process also require s a systematic review and management acceptance of the start-up preparation work for the rig and crews along with the third party technical audit work on the rig and the rig’s well control equipment. This review and audit process measures the ri g’s ability to handle an unplanned well control event and provides assurance that the rig can successfully mitigate a loss of well control event and prevent it fr om becoming a blowout scenario.

 Barrier Philosophy: For all well designs, Anadar ko requires and uses a redundant barrier philosophy, that being two independent barriers for both internal and external flow paths in the final wellbore. It is also standard practi ce to conduct pressure testing, in accordance with the applicable regulations, to evaluate integrity on all relevant barriers. In addition, all intermed iate and production casings returned to the wellhead will be locked down before subse quent wellbore constr uction proceeds.

 BOP and well control equipment: The rig will have an 18-3/4" 15,000 psi BOP with primary and secondary BOP control systems. The BOP will have been completely recertified compliant to OEM sp ecifications and all applicable federal regulations by a qualified third party. Prio r to commencement of operations at the Walker Ridge Block 51 #1 (Location “C”) well an independent third party verification was obtained to verify that th e subsea BOP was designed for the specific equipment on the rig and this specific well design.

 BOP and well control equipment testing : To ensure effectiveness of the BOP and well control equipment, a testing program was conducted prior to running the BOP and then during the well operations at th e Walker Ridge Block 51 #1 (Location “C”) well. This testing program will be in compliance with applicable federal regulations for pressure and function te sting and will also provide periodic assessment on the performance of both primary and secondary BOP control systems including actual interface operations with the ROV and the ROV panel.

 Well control training and drills: Anadarko requires that key nominated onshore and offshore positions including rig contract or personnel to hold a WellCAP, or equivalent, well control traini ng certificate, renewable ever y two years for the type of floating drilling operation being conducted. Anadarko also monitors compliance of its personnel with the applicable federal regulations, including those found in 30 CFR Part 250 Sub-Part O.

A comprehensive program of well control drills will be conducted offshore to ensure readiness to identify and then manage a well control situation and thereby minimize the potential for a well control event to lead to a blowout scenario.

### h) Arrangements for drilling a relief well

 Anadarko maintains a master agreement with Wild Well Control for advice, management, engineering, well kick pre and post modeling, and resource support for an unplanned loss of well control event. In the event of any well control event, Wild Well Control would be cont acted and mobilized if re quired to support Anadarko’s operational team both in the onshore and offshore locations. This agreement and expertise, along with additional equipmen t access, enhances th e ability to conduct effective and early interventi on in the event of a blowout.

 The conceptual relief well design will be similar to the design of the Walker Ridge Block 51 #1 (Location “C”) in that casing weights, gr ades and setting points are anticipated to be identical or very simila r. A finalized relief well design can be prepared within two days of initialization.

 A block wide shallow hazard assessment was previously submitted for Walker Ridge Block 51 under Plan Control No: N-9174. The potential for high density chemosynthetic communities in the study area were negligible. Depending on the nature of the blowout scenario, well geometry, and total depth required to intersect the blowout, the most suitable surface location will be chosen and submitted for approval as the location for the relief well.

 Anadarko’s philosophy is to carry an adequate inventory of well construction equipment to drill a complete well from surface to total depth. Back-up long lead equipment equivalent to the original well design will be carried in stock to allow a rapid response. This includes a spare deepwater sub-sea wellhead system and the large OD casing (36", 22", 18", 16", and 13-5/ 8") and connectors re quired for the first part of the well. Smaller OD casing is considered readily available on the ground in the GoM and would be resourced out of ex isting inventory or from suppliers as required.

 Existing service agreements will be in pl ace for support services including drilling fluids, casing running, cementing, ROV’s, so lids control, mud logging, directional drilling, LWD/MWD, logging, boats and helicopters.

 Specialist services for range finding to dri ll the relief well in close proximity to the original wellbore at the re servoir depth may potentially be provided through Vector Magnetics LLC. During drilling operations Anadarko maintains in-house directional drilling services personnel, (e.g. Schlumberger and/or Halliburton), to support and supplement Vector Magnetics under our ex isting directional dr illing agreements.

### C GEOLOGICAL AND GEOPHYSICAL INFORMATION

(a) Geological Description

Discussions regarding geologic information are considered proprietary and have been omitted from this public copy of the EP, along with so me of the associated geologic attachments.

(b) Structure Contour Maps

Current structure maps drawn to the top of each productive hydrocarbon sand showing the entire lease block, the surface locations of each well and locations of geological cross-sections, are enclosed as Attachment C-1.

(c) Interpreted 2-D and/or 3-D Seismic Lines

Interpreted seismic lines are enclosed as Attachment C-2.

(d) Geological Structure Cross-Sections

Interpreted geological structure cross-sections showing the locat ion and depth of each proposed well are enclosed as Attachment C-3.

(e) Shallow Hazards Report

A Shallow Hazards Report prepar ed by AOA Geophysics, Inc. was previously submitted with the Initial Exploration Plan (Plan Control No: N-9174) that covered Walk er Ridge Blocks 8, 51 and 52.

(f) Shallow Hazards Assessment

The proposed well locations in Walker Ridge Bl ock 51 will utilize the S ite Clearance Letters from the previously approved Walker Ridge Block 51 #1 and #2 (Location “C” and “D”). A copy of the Walker Ridge Bloc k 51 “C” and “D” site clearanc e letters are enclosed as Attachment C-4 since the proposed “CC” and “DD” loca tions are within 100' of the approved locations.

(g) High-resolution Seismic Lines

High resolution seismic lines are enclosed as Attachment C-5.

(h) Stratigraphic Column

A generalized stratigraphic column depicting the wells from the seafloor to total depth is included as Attachment C-6.

### (i) Time Vs. Depth Tables

The proposed activities under this EP are not cons idered to be in areas where there is no well control. Therefore, a seismic travel time versus depth table is not required per NTL No. 2008- G04.WR51 Proposed Location C 1 AOA Geophysics Inc. Marine Geoscience Division 2500 Tanglewilde, Suite 120 Houston, TX 77063 713

- 532

- 2624

Letter Report No. 40 64

- ANA

- GOM

- WR 51C 08 March 2011
Anadarko Petroleum Corporation 1201 Lake Robbins The Woodlands, Texas 77380

Attention: M r. Rick Kincaid

Site Clearance Letter Location C Block 51 , Walker Ridge Protraction Area

UTM Zone 15, NAD 1927 X = 2,104,204 ft Y = 9,767,106 ft Longitude: 91.576445 ° W Latitude: 26.909323 ° N Nearest I nline 31700 Nearest Crossline 3174 2,516 ft FE L 6,174 ft F N L

Introduction. AOA Geophysics Inc. (AOA) was contracted by Anadarko Petroleum Corporation to prepare a site clearance letter for Location C in Block 51
, Walker Ridge Protract ion Area. This letter report describes well site specific conditions but often refers to conditions and findings described in the main block

- wide shallow hazards report s for Walker Ridge blocks Southern WR7, Southern WR8, North

central WR51, and North

- cent ral WR52 in the Walker Ridge Protraction Area
, Gulf of Mexico, report number 4026

- ANA

- GOM dated 28 March 2008

, prepared for Anadarko Petroleum Corporation by AOA Geophysics Inc . The principal scope of this site clearance letter is to assess seafloor disturbance from drilling with respect to possible deepwater benthic communities and to identify and assess potential drilling hazards in the tophole section to a limit of about 1.5 seconds below mudline ( BML ) or top of salt, whichever is shallower

. If the well is drilled from a moored drilling rig, the anchor zone must be assessed in addition to the well site. We have specifically assessed conditions between 5,000 ft and 13,000 ft of the wellbore, as the grounded anchor chains should fall between those distances, with an assessment within an additional buffer zone of 1,000 ft beyond the maximum potential anchor spread

. This site clearance letter is based on the interpretation of reprocessed 3- D exploration seismic data integrated with offset well data. Annotated data examples of the nearest in line and crossline from the 3- D survey are attached. A 1:12,000 water depth and seafloor features map shows the proposed location relative to seafloor features (Anchor Chart C)

. The proposed location with a 2,000 ft radius circle and a 1,000

- foot buffer area beyond the approximate maximum anchor radius are shown as per Bureau of Ocean Energy Management, Regulation and Enforcement (BOEMRE) Notice to Lessee's (NTL) No. 2009

- G40

. The attached chart conforms to the digital structure requirements for drawings as per NTL No. 2008

- G05

. The proposed wellsite is not in an area that requires an archeological assessment (NTLs 2008

- G20, 2006

- G07, and 2005

- G07)

. Data Set and Offset Well Information. The 3

- D data were reprocessed by AOA Ge ophysics Inc to enhance resolution in the tophole section. The data show significant energy above 50 Hz with good signal to noise ratio and are consistent with the guidelines for the use of 3

- D seismic data for shallow hazards analysis. The 3

- D data are centered on WR51 and WR52 and cover twelve blocks. FrequencyWR51 Proposed Location C 2 and power spectra show significant content at 50 Hz and higher in the tophole section at the well site. At 50 Hz and assuming the average velocity of the tophole sediments to be approximately 5,500 ft/sec, the limit of separability ( λ /4) is about 27.5 ft. Data were provided at a 4 ms vertica l sampling rate
, were loaded to 4 seconds two

- way traveltime ( TWT ), and interpreted to approximately 3 seconds TWT (0.5 seconds BML because of shallow salt)

. Inl ines are spaced 41.01 04 ft (12.5 m) and crosslines are spaced 65.616 6 ft (20 m) apart

. Inline increment is 5 and crossline increment is 1

. These data meet or exceed the current NTL requirements including the requirements for the frequency and power conte nt ( Figure Amplitude and Power Spectrum ). Tophole logs and drilling reports from WR08#1 ( 5,819 to 7,736 ft) were reviewed in the assessment of geological conditions and constraints for this proposed location.
Depth Conversion. The water depth at the well site was calculated using the velocity function published by Advocate and Hood (1993). This function is based on velocimeter profiles from the northern Gulf of Mexico and is expected to be accurate to about ±1 6.8 ft (~0. 3 % of water depth) at this location

. The water depth was further calibrated by additional wide azimuth seismic data that ties the location WR08#1 well (water depth 5819 ft BSS , which was within 4 ft of the uncalibrated water depth calculation ). Subsurface depths at the well site are based on depths derived from well WR 0 8#1 (API: 608124003400 )

. The following function was used for subsurface depth conversions in this report.

**D = 3780.2 (T)** 
where D is depth (ft BML) and T is two

- way
- travel time (second s BML ).

Water Depth and Seafloor Slope

. The water depth at proposed Location C is predicted to be 5, 838 ft below sea surface (BSS) . The local slope (gradient) of seafloor at the proposed well site is less than 1o dipping to the southwest

. Seafloor F eatures. In general, WR51 is located within an area of irregular seafloor controlled by the interaction and migration of shallow salt. Although there are possible localized low

- angle surficial mass movement deposits to the east and northeast, especially in WR52, and there is a steep scarp to the west in WR50, in general the block WR51 has no obvious evidence of seafloor instability. Furthermore the immediate region around the proposed well location C has no evidence for seafloor instability within 2,000 ft of the well site. The nearest seafloor fault is northeast

- southwest trending, dipping southeast , and is about 300 ft east of the proposed wellsite

.
The re is no evidence for high

- density benthic communities in the vicinity of the well location C. With in 2,000 ft of the proposed location, there are no interpreted seeps that would support a high

- density chemosynthetic community, and there are no interpreted seafloor hardgrounds or stable bathymetric highs that might support a slow

- growing filter

- feeding coldwater coral community

. The nearest reported deepwater benthic community is located in WR269 ( 26°41.07'
, 91°40.28' ) about 16.5 miles SW from proposed well WR51C.

Man

- Made Obstructions

. The nearest existing well location is WR8#1, more than 5,64 2 ft NE from the proposed well site. No other man

- made features or other potentially hazardous seafloor conditions are identified in the vicinity of the proposed well site

. However, there may be uncharted obstructions present that are not detectable within the resolution of the reprocessed 3- D data set, so it is recommended that an ROV be used to inspect the seafloor at the proposed well site immediately before spud

- in to confirm that there are no seafloor obstructions.

Assessment of Touchdown Area for Notional A nchor Pattern. The BOEMRE NTL 200 9-G4 0 mandates that proposed seafloor disturbances (including those caused by anchors, anchor chains, wire ropes, seafloor template installation, and pipeline construction) be more than 500 ft from areas that could support high

- density deepwater benthic communities. If design requires seafloor disturbances between 250 ft and 500 ft of potential deepwater benthic communities a state

- of

- the

- art positioning system (e.g., differential global positioning system) on anchor

- handli ng vessel(s) must be used, and the BOEMRE must receive plats that depict the “as

- placed” location of all anchors, anchor chains, and wire ropes within 60WR51 Proposed Location C 3 days after completion of operations to demonstrate that the features or areas were not physically impa cted by the anchoring activities.
The notional anchor touchdown area is between 5,000 and 13,000 ft from the proposed well site. An additional 1,000

- foot buff er area beyond the approximate maximum anchor radius is between 13,000 ft and 14,000 ft from the proposed well site. The area s contain ridges and scarps associated with salt tectonics

.
There are numerous faults within the anchor touchdown area, predo minantly to the northeast and south (see Anchor Chart C ). The immediate vicinity of the fault scarps should be avoided if possible but otherwise the faults should not significantly constrain the anchor placement. In the vicinity of the faults, there may be locally variable soil properties and steep slopes. The steep slopes associated with mini

basin formation and salt tectonics are located west and southwest of the well location at slightly greater than 14,000 ft. Some small channels and gullies are present in the touchdown area.

There are five sites, two in the notional touchdown area and three in the additional 1,000

- foot buffer area, that are interpreted to have potential seepage of hydrocarbons and/or brines ( Anchor Chart C ). These sites may ho st high

- density chemosynthetic communities. None of the bathymetric highs or steep margins, where nutrient

- rich bottom water is necessary to support a high

- density epi

- benthic community of filter feeders, was interpreted to be stable over the length of time necessary to establish a slow

- growing coldwater coral community (typically around 1 meter of growth per 100 years). The three regions likely to have the required exposure to nutrient

- rich bottom waters that were examined most closely in the data were: the scalloped head scarp in the northeast of WR8, the steep scarp running north

- south through WR6, WR50, WR94; and the irregular seafloor resulting from mass movement predominantly in WR52, WR96, and WR53 . There were no obvious seafloor hardgrounds interpret ed from the seafloor amplitude data that may form a suitable substrate for a high

- density coldwater coral community in the provided data and especially in these regions. Because the exposure to nutrient

- rich bottom water, a hard substrate on which to ancho r, and greater than centuries

- scale stability in the geomorphology are all required for high

- density epi

- benthic coldwater coral communities, the only sites interpreted to have potential for high

- density biomass are the five seep locations with potential f or chemosynthetic activity ( Anchor Chart C ). These five sites, which are possible high

- density deepwater benthic communities, should be avoided by more than 500 ft during anchor placement as per NTL requirements.
Tophole Stratigraphy. The seafloor and two subsurface horizons
, H1 and Top of Salt, were mapped. Depths below sea surface and below mudline to each of these intervals are included on the attached Tophole Prognosis Chart.

Unit 1 is about 284 ft thick and is composed of flat

- lying and laterally continuous reflectors possibly representing recent mud -r ich sediments.

Unit 2 is about 468 ft thick

. The reflectors show chaotic feature s in the unit due to the vertical and lateral movement of the salt . The unit is subdivided into an upper and lower section. The upper section is interpreted to be composed of mostly clay

- prone sediment interbedded with thin mass transport complexes (120 ft thick). The lower section is interpreted to be composed of mostly clay

- prone sediment with possible sands (348 ft thick)

. Salt stringers may be present near base of the unit. The base of this unit is the T op of S alt

. Unit 3 composed of salt. The top of salt is at 752 ft BML. The slope at the top of salt is 5.3o to the south. Possible inclusions and rafted sediments in the uppermost salt.

Fault Penetrations. Although the area is faulted to the east and northeast of the wellsite, no obvio us fault planes are interpreted to crosscut the wellbore path at proposed well location C. The closest prominent seafloor fault is located 300 ft to the east of the well location

.WR51 Proposed Location C 4 Gas Hazards. No amplitude anomalies suggestive of gassy sediments are penetrated at the proposed well site. There is a negligible risk for gas hazards at the proposed well location C

. The nearest interpreted gassy sediments are about 563 ft NE in Unit 2

. Shallow

- Water

- Flow (SW F). A negligible risk for severe SWF is assessed. There is a possible contribution of salt movement to overpressure pore fluids. However, it is not a strong driver of overpressure in thin shallow sediments that overlie the salt.
Suitability for Temporary Occupation for Drilling. Proposed WR51 Location C is suitable for temporary occupation for drilling provided that the conditions and constraints that have been identified are considered and planned for in the final well design.WR51 Proposed Location C 5 We appreciate the opportunity to work with you on this project and look forward to continuing as your geohazards and marine geoscience consultants. Please call us at 713

- 532

- 2624 if you have any questions or if we can offer further assistance.

Sincerely,

AOA GEOPHYSICS INC.

Brenda I. Monsalve Geophysicist - Ma rine Geohazards Specialist

Dan McConnell, P.G. Manager - Marine Geohazards

Attachments:

• Description of 3

- D Seismic Data including Amplitude and Power Spectrum Figure and Wavelet Figure

• Figure Appendix C

- 51C

- 1: Tophole Prognosis Ch art Location C , Block 5 1 , Walker Ridge Area

• Figure Appendix C - 5 1C

- 2: 3- D Seismic Record, Line 31700 , Location C

, Block 5 1 , Walker Ridge Area

• Figure Appendix C - 51C

- 3: 3

- D Seismic Record, Crossline 3174 , Location C , Block 51 , Walker Rid ge Area

• Water Depth & Seafloor Features Showing Potential Anchor Touchdown for Proposed Well C

, Walker Ridge ( WR ) 51
, and Vicinity, Gulf of Mexico, Anchor Chart C (1:12,000)WR51 Proposed Location C Description of 3

- D Seismic Data Description of 3

- D Seismic Data Sets:
The 3

- D seismic surveys that have been provided to AOA Geophysics Inc., by Anadarko

, are of good quality to interpret the shallow section. The 3

- D seismic data volume called VTS Walker Ridge I ( wr ph1_3d ) are interpreted around the proposed well sites and are used for most of the surface and all of the subsurface interpretation. These data are thirty

- two

- bit format. The 3

- D seismic data parameters for VTS Walker Ridge I are described in the table below:

3

- D Sei smic Data **VTS Walker Ridge I (wrph1_3d) Spacing, Increment, and**  **Orientation** Spacing Increment Orientation Inlines 41.0143 ft (12.5 m) 5 EW Traces 65.6161 ft (20 m) 1 N S **Frequency Content in Tophole Section**  Spectral analysis shows significant (0.45 to 0.65 on a normalized scale of 0 to 1) 50 Hz frequency content in the data at each of the proposed well locations. **Reprocessed for Shallow Section?**  Yes, spectral whitening

**Processed sample interval** Acquired at 2 ms - Processed at 4 ms **Acquisition Par ameters**  • Acquisition Contractor CGG Veritas

• Vessel Polar Princess/Polar Search

• Date Available 1998

• Source Airgun

• Streamer length 7,200 meters

• Shotpoint Interval 37. 5 meters

• CMP Xline 40 m

• Record Length 12.5 seconds

• Nominal Fold 48 **Processing Parameters** • Reformat

• Anti- alias filter (Minimum Phase, Out – 90 Hz)

• Resample to 4 ms

• Adjustment for differences in recording systems

• Trace edits

• Merge navigation with seismic

• Spherica l divergence correction (V2T)

• Mute - First break suppression

• Gap deconvolution based on waterbottom

- Operator Length: 240 ms

- Predictive Gap: 24 ms

- 15 trace average

• Mutiple attenuation, Radon transform algorithm

• DMO velocity analysis (2 km grid)

• B in offset regularization (Utilizing 2 km grid)

• 3D dip moveout correction on common offsets, (V(Z))

• Bin fold normalization

• Interpolation to 12.5 x 20 m bins on each common offset

• One pass phase shift migration of each offset (V(Z))

• Migration velocity analysis (Moves Velocity Analysis) 0.5 km grid

• 3D normal moveout correction (Moves Velocity Field)

• Offset weighting - based on waterbottom

• Mute - based on waterbottom

• Common mid

- point stack 12.5 x 20 m bins

• Inverse migration of MOVES stack, (V(Z))

• One pass migration with velocity model generated from inversion of moves velocities (GLINVEL)

• Datum correction to sea level +10 ms **Quality of Primary 3**

**- D Data with**  **respect to NTL Guidelines and Comments**  • The 32 bit data were loaded as 16 bit format for interpretation and these data show good quality.WR51 Proposed Location C Description of 3

- D Seismic Data • The data show significant energy in the 50 Hz range.

• Assuming a shallow section velocity of ~5500 ft/sec at 50 Hz the limit of separability between reflectors is approximately 27.5 ft.

• There are no indications of over migration artifacts in the shallow section.

• The seabed reflector is continuous at faults and is characterized by a wavelet of stable form.

• The data are good at imaging gas.

• Faults are well imaged in the data.0

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 A

m p l i t

u d

e

Frequency (Hz) 

### Reprocessed Amplitude Spectrum Well WR51_C

WR51_C

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 P

o

w
e
r

Frequency (Hz) 

### Reprocessed Power Spectrum Well WR51_C

WR51_C

WR52C Amp and Power Spectra Report No. 4064-ANA-GOMWaveletReport No. 4064-ANA-GOM

- 0.6 - 0.4 - 0.2 0 0.2 0.4 0.6 0.8 1



### - 0.05

- 0.04

- 0.03

- 0.02

- 0.01 0 0.01 0.02 0.03 0.04 0.05 Original: 33 ft
Reprocessed:27.5ft



### 0.024 sec

0.021 sec Wavelet

N

o

r

m

a l i

z

e d

A

m p l i
t

u d

e



### Time (sec)3100.0 3200.0

Trace: WR51_C WR51_D 1027 ft

2.400

2.500

2.600

2.700

2.800 WR51_A WR51_A Inferred Lithology and Comments

E W Event and Unit Designations Depths

BML (ft) BSS

(ft)

TOPHOLE PROGNOSIS CHART

LOCATION C BLOCK 51, WALKER RIDGE AREA Thickness (ft) TWT BSS (s)

thole51C.cdr Hazardous Shallow Gas Risk Shallow

Water Flow Risk

TWT: Two-Way Travel Time BML: Below Mudline BSS: Below Sea Surface 3-D Seismic Record at Proposed Location C Walker Ridge Block 51 X = 2,104,204 FT, Y = 9,767,106 FT ~1000 ft LINE 31700

0 5838 2.402

284 6122 2.477

404 6242 2.509

752 6590 2.601

2261 8099 3.000 SEAFLOOR

1 284 NEGLIGIBLE NEGLIGIBLE

HOR. 1

2 120 NEGLIGIBLE NEGLIGIBLE

Topsalt

3 348 NEGLIGIBLE NEGLIGIBLE

salt

1509 NEGLIGIBLE NEGLIGIBLE 468 Seafloor slopes less that 1 degree to southwest
Marine clays with mass transport deposits

Mostly clay-prone sediments with possible mass transport deposits

Most clay-prone deposits with possible sand

WR 08#1 is located 5,642 ft NE from proposed well WR51C. Reflectors show a chaotic feature in the unit due to the vertical and lateral salt movement. Faults may cross the wellbore in the unit, but do not have clear seismic expression.Report No. 4064-ANA-GOM-WR51CFigure Appendix C-51C-1 Slope at top of salt is 5.3o to the south

All depths and thicknesses are approximate and are based on drilling report of WR08#1 provided by Anadarko A possible salt stringer was found 140 ft above top of salt in WR08#1 well.

Possible inclusions and rafted sedimentsPos 31700.0 2800.0 31700.0 2900.0 31700.0 3000.0 31700.0 3100.0 31700.0 3200.0 31700.0 3300.0 31700.0 3400.0 31700.0 3500.0 31700.0 3600.0 Line: Trace:
15000 20000 25000 30000 35000 40000 45000 Offset: WR51_C WR51_D

2.400

2.500

2.600

2.700

2.800

2.900

3.000Report No. 4064-ANA-GOM-WR51CFigure Appendix C-51C-2

3-D Seismic Record, Line 31700, Location C, Block 51, Walker Ridge AreaTwo-Way Travel Time (s) Unit 1

Unit 2 H1

Topsalt 5000 ft WR51 WR52

R
e l
a t i

v e

A
m p l i t
u d
e

Neg W E

Salt Salt Possible gassy sediments Possible gassy sediments30800.0 3174.0 31300.0 3174.0 31800.0 3174.0 32300.0 3174.0 32800.0 3174.0 33300.0 3174.0 Line: Trace:
15000 20000 25000 30000 35000 40000 45000 Offset: WR51_C

2.300

2.400

2.500

2.600

2.700

2.800

2.900Report No. 4064-ANA-GOM-WR51CFigure Appendix C-51C-3

3-D Seismic Record, Crossline 3174, Location C, Block 51, Walker Ridge Area Unit 1

Unit 2 Seafloor

H1

Topsalt WR51 WR07 S NTwo-Way Travel Time (s) 5000 ft

Salt Salt Pos

R
e l
a t i

v e

A
m p l i t
u d
e

Neg