UNITED STATES GOVERNMENT MEMORANDUM

To: Public Information (MS 5030) Plans Section, Office of Field Operations (MS 5231)
Public Information copy of Exploration Plan Control # - N-09583 Type - Initial Exploration Plan Lease(s) - OCS-G33854 Block - 823 Green Canyon Area OCS-G33858 Block - 867 Green Canyon Area Operator - Apache Deepwater LLC GC 823 Wells A, B and C, GC 867 Wells A through D 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.

Chiquita Hill Plan Coordinator Description - Rig Type - Subject: From: October 6, 2011

## PUBLIC INFORMATION June, 2011 Amended August 18, 2011 

## JOINT INITIAL EXPLORATION PLAN

Lease Number(s): OCS-G 33854 & OCS-G 33858 Area/Block: Green Canyon Blocks 823 and 867 Prospect Name: Parmer Offshore: Louisiana

Submitted by: Apache Deepwater LLC 2000 W. Sam Houston Pkwy S Suite 1600 Houston, TX 77042 Terri Young (713) 296-7456 Terri.young@apachecorp.com
Estimated start-up: October 15, 2011

Authorized Representative: Copies Being Submitted: Cindy Bailey Proprietary: 1 Copy & CD J. Connor Consulting, Inc. Public Info: 1 Copy & CD 16225 Park Ten Place, Suite 700 Houston, Texas 77084 For BOEMRE: (281) 578-3388 Plan No. Cindy.bailey@jccteam.com Assigned to:

### Green Canyon Blocks 823 and 867 (Control Number N-9583) Record of Changes Date Section Page Page Revision
07/21/11 Appendix H Addition Wellbore schematic Appendix H Addition Directional Survey Appendix H Exhibit B Confirmed Location G is equivalent to WCD Well GC 867 D Appendix H CDs Submitted .mer and .nod CDs in digital format 08/01/11 Appendix F Attachment F-1 Genera ted Wastes Discharges Table Appendix L Attachment L-1 Trans ported Wastes to Shore Table
08/18/11 Appendix H All Add Mariner Energy’s Comp any Number, Amend WCD Barrels per BOEMRE request, and Revise Spill Response Discussion

### Apache Deepwater LLC
JOINT INITIAL EXPLORATION PLAN
LEASES OCS-G 33854 and OCS-G 33858

APPENDIX A Plan Contents
APPENDIX B General Information
APPENDIX C Geological, Geophysical Information
APPENDIX D H2S Information
APPENDIX E Biological, Physical and Socioeconomic Information
APPENDIX F Wastes and Discharge Information
APPENDIX G Air Emissions Information
APPENDIX H Oil Spills Information
APPENDIX I Environmental Monitoring Information
APPENDIX J Lease Stipulations Information
APPENDIX K Environmental Mitigation Measures Information
APPENDIX L Support Vessels and Aircraft Information
APPENDIX M Onshore Support Facilities Information
APPENDIX N Coastal Zone Management Act (CZMA) Information
APPENDIX O Environmental Impact Analysis
APPENDIX P Administrative Information

### LIST OF ATTACHMENTS
A-1 OCS Plan Information Form A-2 Well Location Plat A-3 Bathymetry Map A-4 Pay.Gov Receipt C-1 Structure Contour Maps C-2 3-D Seismic Lines C-3 Geological Structure Cross Sections C-4 Shallow Hazard Assessment C-5 Stratigraphic Column E-1 Bathymetry and Seafloor Features Map F-1 Projected Generated Wastes H-1 OSRP Certification Letter H-2 Nodal Analysis Data L-1 Solid and Liquid Waste Transportation L-2 Vicinity Map N-1 Coastal Zone Management Consistency Certification

### Apache Deepwater LLC Page A-1 Joint Initial Exploration Plan June, 2011 Green Canyon Blocks 823 and 867 (OCS-G 33854 & OCS-G 33858) 

## APPENDIX A PLAN CONTENTS (A) PLAN INFORMATION FORM Under this Exploration Plan, Apache Deepwater LLC (Apache Deepwater) proposes to drill and complete seven wells. The wells will be drilled with a semisubmersible MODU. Water depth in these blocks ranges between 3,646 f eet to 6,397 feet. See attached OCS Plan Information Form – Form BOEMRE-137, included as Attachment A-1

. (B) LOCATION: Included as Attachment A-2 is a Well Location Map depicting the proposed surface and bottom location for each well.
Also included as Attachment A-3 is a Bathymetry Map showi ng the water depths across the lease block. The maximum radius of anchor spread of the associat ed drilling unit at each proposed well locati on is included as Attachment E-1. (C) SAFETY AND POLLUTION PREVENTION FEATURES A description of the drilling unit is includ ed on the OCS Plan Information Form. Rig specifications will be made part of each Application for Permit to Drill. Apache Deepwater will drill these wells with a semisubmersible dril ling rig, which is equipped with a subsea BOP. Once a rig is contracte d, BOP information and schematics will be included as a part of the Application for Permit to Drill. Safety features on the drilling unit will includ e well control, pollution prevention, and blowout prevention equipment as described in Title 30 CFR Part 250, Subparts C, D, E, and F; and as further clarified by BOEMRE Notices to Less ees, and current policy making invoked by the BOEMRE, Environmental Protection Agency and the U.S. Coast Guard. A ppropriate life rafts, life jackets, ring buoys, etc., will be maintained on the facility at all times. Pollution prevention measures include installation of curbs, gutters, drip pans, and drains on drilling deck areas to collect all contaminants and debris.

### Apache Deepwater LLC Page A-2 Joint Initial Exploration Plan June, 2011 Green Canyon Blocks 823 and 867 (OCS-G 33854 & OCS-G 33858) (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

(SG) Fuel Oil (Marine Diesel) Semisubmersible 3331 2 6662 .848 Fuel Oil Day Semisubmersible 214.8 1 214.8 .848 Emergency Generator Semisubmersible 23.8 1 23.8 .848
Lube Oil Services Semisubmersible 1026.7 1 1026.7 .93 Dirty Lube Oil Semisubmersible 33.4 1 33.4 .93 Dirty Bilge Semisubmersible 45.9 1 45.9 .848 

### (E) ADDITIONAL MEASURES Apache Deepwater does not propose additional safety, pollution prevention, or early spill detection measures beyond t hose required by 30 CFR 250. (F) Cost Recovery Fee Included as Attachment A-4 is a pay.gov receipt in the amoun t of $24,094 to cover operations proposed in this plan.U.S. Department of the Interior OMB Control Number: 1010-0151 Minerals Management Service OMB Approval Expires: July 31, 2008 

## OCS PLAN INFO RMATION FORM

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

### ATTACHMENT A-1 GENERAL INFORMATION Type of OCS Plan: X Exploration Plan (EP) Deve lopment Operations Coordination Document (DOCD) Company Name: Apache Deepwater LLC BOEMRE Operator Number:03165 Address: 2000 West Sam Houston Pkwy South Contact Person: Cindy Bailey Suite 2000 Phone Number: (281) 578-3388 Houston, Texas 77042 Email Address: cindy.bailey@jccteam.com Lease(s):G33854, G33858 Area: Green Canyon Block(s): 823 & 867 Project Name (If Applicable): Parmer Objective(s): Oil Gas Sulphur Salt Onshore Base: Fourchon Distance to Closest Land (Miles): 130 Description of Proposed Activities (Mark all that apply) Exploration drilling Development drilling Well completion Installation of production platform Well test flaring (for more than 48 hours) Installation of production facilities Installation of caisson or platform as well protection structure Installation of satellite structure Installation of subsea wellheads and/or manifolds Commence production Installation of lease term pipelines Other (Specify and describe) Have you submitted or do you plan to submit a Conservation Information Document to accompany this plan? Yes x No Do you propose to use new or unusual technology to conduct your activities? Yes x No Do you propose any facility that will serve as a host facility for deepwater subsea development? Yes x No Do you propose any activities that may disturb an BOEMRE-designated high-probability archaeological area? Yes x No Have all of the surface locations of your proposed activitie s been previously reviewed and approved by BOEMRE? Yes x No Tentative Schedule of Proposed Activities Proposed Activity Start Date End Date No. of Days Drill, complete and TA GC 823 Well A 10-15-11 12-7-11 53 Drill, complete and TA GC 823 Well B 12-08-11 01-30-12 53 Drill, complete and TA GC 823 Well C 11-01-12 12-24-12 53 Drill, complete and TA GC 867 Well A 12-25-12 02-16-13 53 Drill, complete and TA GC 867 Well B 02-17-13 04-11-13 53 Drill, complete and TA GC 867 Well C 11-01-13 12-24-13 53 Drill, complete and TA GC 867 Well D 12-25-13 02-16-14 53 Description of Drilling Rig Description of Production Platform Jackup Drillship Caisson Tension leg platform Gorilla Jackup Platform rig Well protector Compliant tower Semisubmersible Submersible Fixed platform Guyed tower DP Semisubmersible Other (Attach Description) Subsea manifold Floating production system Drilling Rig Name (If Known): Spar Other (Attach description) Description of Lease Term Pipelines From (Facility/Area/Block) To (Facility/Area /Block) Diameter (inches) Length (Feet)

### OCS PLAN INFORMATION FORM (CONTINUED) 

### Include one copy of this page for each proposed well/structure Proposed Well/Structure Location Well or Structure Name/Number (If renaming well or structure, reference previous name): A Subsea Completion Anchor Radius (if applicable) in feet: 10,000 Yes No Surface Location Bottom-Hole Location (For Wells) Lease No. OCS G33854 Area Name Green Canyon Block No. 823 Blockline Departures (in feet) N/S Departure: 960’ FSL E/W Departure: 7,160’ FWL
Lambert X-Y coordinates X: 2,478, 200 Y: 9,853,440
Latitude/ Longitude Latitude: 27.1304443 Longitude: -90.4238109 TVD (Feet): MD (Feet): Water Depth (Feet):4,129’ Anchor Locations for Drilling Rig or Construction Barg e (If anchor radius supp lied above, not necessary) Anchor Name or No. Area Block X Coordinate Y Coordinate Length of Anchor Chain on Seafloor X = Y =
X = Y =
X = Y =
X = Y =
X = Y =
X = Y =
X = Y =
X = Y = Paperwork Reduction Act of 1995 Statement: The Paperwork Reduction Act of 1995 (44 U.S.C. Chapter 35) requires us to inform you that BOEMRE collects this information as pa rt of an Apache Deepwater LLC’s Exploration Plan or Development Operations Coordination Document submitted for BOEMRE approval. We use the information to facilitate our review and data entry for OCS plans. We will protect propr ietary data according to the Fr eedom of Information Act and 30 CFR 250.196. An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid Office of Mana gement and Budget Control Number. The use of this form is voluntary. The public reporting burden for this form is in cluded in the burden for preparing Exploration Plans and Development Operations Coordination Documents. We estimat e that burden to average 580 hours per response, including the time for reviewing instructions, gathering and mainta ining data, and completing and reviewing the form. Direct comments regarding the burden estimate or any other aspect of this form to the Information Collection Clearance Officer, Mail Stop 4230, Minerals Management Service, 1849 C Street, N.W., Washington, DC 20240

.

### OCS PLAN INFORMATION FORM (CONTINUED) 

### Include one copy of this page for each proposed well/structure Proposed Well/Structure Location Well or Structure Name/Number (If renaming well or structure, reference previous name): B Subsea Completion Anchor Radius (if applicable) in feet: 10,000 Yes No Surface Location Bottom-Hole Location (For Wells) Lease No. OCS G33854 Area Name Green Canyon Block No. 823 Blockline Departures (in feet) N/S Departure: 1,884’ FSL E/W Departure: 6,538’ FWL
Lambert X-Y coordinates X: 2,477,578 Y: 9,854,364
Latitude/ Longitude Latitude: 27.1330196 Longitude: -90.4256638 TVD (Feet): MD (Feet): Water Depth (Feet): 4,072’ Anchor Locations for Drilling Rig or Construction Barg e (If anchor radius supp lied above, not necessary) Anchor Name or No. Area Block X Coordinate Y Coordinate Length of Anchor Chain on Seafloor X = Y =
X = Y =
X = Y =
X = Y =
X = Y =
X = Y =
X = Y =
X = Y = Paperwork Reduction Act of 1995 Statement: The Paperwork Reduction Act of 1995 (44 U.S.C. Chapter 35) requires us to inform you that BOEMRE collects this information as pa rt of an Apache Deepwater LLC’s Exploration Plan or Development Operations Coordination Document submitted for BOEMRE approval. We use the information to facilitate our review and data entry for OCS plans. We will protect propr ietary data according to the Fr eedom of Information Act and 30 CFR 250.196. An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid Office of Mana gement and Budget Control Number. The use of this form is voluntary. The public reporting burden for this form is in cluded in the burden for preparing Exploration Plans and Development Operations Coordination Documents. We estimat e that burden to average 580 hours per response, including the time for reviewing instructions, gathering and mainta ining data, and completing and reviewing the form. Direct comments regarding the burden estimate or any other aspect of this form to the Information Collection Clearance Officer, Mail Stop 4230, Minerals Management Service, 1849 C Street, N.W., Washington, DC 20240.

### OCS PLAN INFORMATION FORM (CONTINUED) 

### Include one copy of this page for each proposed well/structure Proposed Well/Structure Location Well or Structure Name/Number (If renaming well or structure, reference previous name): C Subsea Completion Anchor Radius (if applicable) in feet: 10,000 Yes No Surface Location Bottom-Hole Location (For Wells) Lease No. OCS G 33858 Area Name Green Canyon Block No. 867 Blockline Departures (in feet) N/S Departure: 2,990’ FNL E/W Departure: 5,933’ FWL
Lambert X-Y coordinates X: 2,476,973 Y: 9,849,490
Latitude/ Longitude Latitude:27.1196541 Longitude: -90.4278294 TVD (Feet): MD (Feet): Water Depth (Feet):4,158’ Anchor Locations for Drilling Rig or Construction Barg e (If anchor radius supp lied above, not necessary) Anchor Name or No. Area Block X Coordinate Y Coordinate Length of Anchor Chain on Seafloor X = Y =
X = Y =
X = Y =
X = Y =
X = Y =
X = Y =
X = Y =
X = Y = Paperwork Reduction Act of 1995 Statement: The Paperwork Reduction Act of 1995 (44 U.S.C. Chapter 35) requires us to inform you that BOEMRE collects this information as pa rt of an Apache Deepwater LLC’s Exploration Plan or Development Operations Coordination Document submitted for BOEMRE approval. We use the information to facilitate our review and data entry for OCS plans. We will protect propr ietary data according to the Fr eedom of Information Act and 30 CFR 250.196. An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid Office of Mana gement and Budget Control Number. The use of this form is voluntary. The public reporting burden for this form is in cluded in the burden for preparing Exploration Plans and Development Operations Coordination Documents. We estimat e that burden to average 580 hours per response, including the time for reviewing instructions, gathering and mainta ining data, and completing and reviewing the form. Direct comments regarding the burden estimate or any other aspect of this form to the Information Collection Clearance Officer, Mail Stop 4230, Minerals Management Service, 1849 C Street, N.W., Washington, DC 20240.

### OCS PLAN INFORMATION FORM (CONTINUED) 

### Include one copy of this page for each proposed well/structure Proposed Well/Structure Location Well or Structure Name/Number (If renaming well or structure, reference previous name): A Subsea Completion Anchor Radius (if applicable) in feet: 10,000 Yes No Surface Location Bottom-Hole Location (For Wells) Lease No. OCS G 33858 Area Name Green Canyon Block No. 867 Blockline Departures (in feet) N/S Departure: 27’ FNL E/W Departure: 5,888’ FWL
Lambert X-Y coordinates X: 2,476,928 Y: 9,852,453
Latitude/ Longitude Latitude: 27.1278025 Longitude: -90.4277813 TVD (Feet): MD (Feet): Water Depth (Feet): 4,106’ Anchor Locations for Drilling Rig or Construction Barg e (If anchor radius supp lied above, not necessary) Anchor Name or No. Area Block X Coordinate Y Coordinate Length of Anchor Chain on Seafloor X = Y =
X = Y =
X = Y =
X = Y =
X = Y =
X = Y =
X = Y =
X = Y = Paperwork Reduction Act of 1995 Statement: The Paperwork Reduction Act of 1995 (44 U.S.C. Chapter 35) requires us to inform you that BOEMRE collects this information as pa rt of an Apache Deepwater LLC’s Exploration Plan or Development Operations Coordination Document submitted for BOEMRE approval. We use the information to facilitate our review and data entry for OCS plans. We will protect propr ietary data according to the Fr eedom of Information Act and 30 CFR 250.196. An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid Office of Mana gement and Budget Control Number. The use of this form is voluntary. The public reporting burden for this form is in cluded in the burden for preparing Exploration Plans and Development Operations Coordination Documents. We estimat e that burden to average 580 hours per response, including the time for reviewing instructions, gathering and mainta ining data, and completing and reviewing the form. Direct comments regarding the burden estimate or any other aspect of this form to the Information Collection Clearance Officer, Mail Stop 4230, Minerals Management Service, 1849 C Street, N.W., Washington, DC 20240.

### OCS PLAN INFORMATION FORM (CONTINUED) 

### Include one copy of this page for each proposed well/structure Proposed Well/Structure Location Well or Structure Name/Number (If renaming well or structure, reference previous name): B Subsea Completion Anchor Radius (if applicable) in feet: 10,000 Yes No Surface Location Bottom-Hole Location (For Wells) Lease No. OCS G 33858 Area Name Green Canyon Block No. 867 Blockline Departures (in feet) N/S Departure: 1,480’ FNL E/W Departure: 2,110’ FWL
Lambert X-Y coordinates X: 2,473,150 Y: 9,851,000
Latitude/ Longitude Latitude: 27.1240202 Longitude: -90.4394800 TVD (Feet) MD (Feet): Water Depth (Feet): 4,267’ Anchor Locations for Drilling Rig or Construction Barg e (If anchor radius supp lied above, not necessary) Anchor Name or No. Area Block X Coordinate Y Coordinate Length of Anchor Chain on Seafloor X = Y =
X = Y =
X = Y =
X = Y =
X = Y =
X = Y =
X = Y =
X = Y = Paperwork Reduction Act of 1995 Statement: The Paperwork Reduction Act of 1995 (44 U.S.C. Chapter 35) requires us to inform you that BOEMRE collects this information as pa rt of an Apache Deepwater LLC’s Exploration Plan or Development Operations Coordination Document submitted for BOEMRE approval. We use the information to facilitate our review and data entry for OCS plans. We will protect propr ietary data according to the Fr eedom of Information Act and 30 CFR 250.196. An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid Office of Mana gement and Budget Control Number. The use of this form is voluntary. The public reporting burden for this form is in cluded in the burden for preparing Exploration Plans and Development Operations Coordination Documents. We estimat e that burden to average 580 hours per response, including the time for reviewing instructions, gathering and mainta ining data, and completing and reviewing the form. Direct comments regarding the burden estimate or any other aspect of this form to the Information Collection Clearance Officer, Mail Stop 4230, Minerals Management Service, 1849 C Street, N.W., Washington, DC 20240.

### OCS PLAN INFORMATION FORM (CONTINUED) 

### Include one copy of this page for each proposed well/structure Proposed Well/Structure Location Well or Structure Name/Number (If renaming well or structure, reference previous name): C Subsea Completion Anchor Radius (if applicable) in feet: 10,000 Yes No Surface Location Bottom-Hole Location (For Wells) Lease No. OCS G 33858 Area Name Green Canyon Block No. 867 Blockline Departures (in feet) N/S Departure: 2,530’ FNL E/W Departure: 3,420’ FWL
Lambert X-Y coordinates X: 2,474,460 Y: 9,849,950
Latitude/ Longitude Latitude: 27.1210600 Longitude: -90.4355211 TVD (Feet): MD (Feet): Water Depth (Feet): 4,250’ Anchor Locations for Drilling Rig or Construction Barg e (If anchor radius supp lied above, not necessary) Anchor Name or No. Area Block X Coordinate Y Coordinate Length of Anchor Chain on Seafloor X = Y =
X = Y =
X = Y =
X = Y =
X = Y =
X = Y =
X = Y =
X = Y = Paperwork Reduction Act of 1995 Statement: The Paperwork Reduction Act of 1995 (44 U.S.C. Chapter 35) requires us to inform you that BOEMRE collects this information as pa rt of an Apache Deepwater LLC’s Exploration Plan or Development Operations Coordination Document submitted for BOEMRE approval. We use the information to facilitate our review and data entry for OCS plans. We will protect propr ietary data according to the Fr eedom of Information Act and 30 CFR 250.196. An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid Office of Mana gement and Budget Control Number. The use of this form is voluntary. The public reporting burden for this form is in cluded in the burden for preparing Exploration Plans and Development Operations Coordination Documents. We estimat e that burden to average 580 hours per response, including the time for reviewing instructions, gathering and mainta ining data, and completing and reviewing the form. Direct comments regarding the burden estimate or any other aspect of this form to the Information Collection Clearance Officer, Mail Stop 4230, Minerals Management Service, 1849 C Street, N.W., Washington, DC 20240.

### OCS PLAN INFORMATION FORM (CONTINUED) 

### Include one copy of this page for each proposed well/structure
Proposed Well/Structure Location Well or Structure Name/Number (If renaming well or structure, reference previous name): D Subsea Completion Anchor Radius (if applicable) in feet: 10,000 Yes No Surface Location Bottom-Hole Location (For Wells) Lease No. OCS G 33854 Area Name Green Canyon Block No. 823 Blockline Departures (in feet) N/S Departure: 3,752 FSL E/W Departure: 2,110’ FWL
Lambert X-Y coordinates X: 2,473,150 Y: 9,856,232
Latitude/ Longitude Latitude: 27.1384041 Longitude: -90.4391521 TVD (Feet): MD (Feet): Water Depth (Feet): 3,944’ Anchor Locations for Drilling Rig or Construction Barg e (If anchor radius supp lied above, not necessary) Anchor Name or No. Area Block X Coordinate Y Coordinate Length of Anchor Chain on Seafloor X = Y =
X = Y =
X = Y =
X = Y =
X = Y =
X = Y =
X = Y =
X = Y = Paperwork Reduction Act of 1995 Statement: The Paperwork Reduction Act of 1995 (44 U.S.C. Chapter 35) requires us to inform you that BOEMRE collects this information as pa rt of an Apache Deepwater LLC’s Exploration Plan or Development Operations Coordination Document submitted for BOEMRE approval. We use the information to facilitate our review and data entry for OCS plans. We will protect propr ietary data according to the Fr eedom of Information Act and 30 CFR 250.196. An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid Office of Mana gement and Budget Control Number. The use of this form is voluntary. The public reporting burden for this form is in cluded in the burden for preparing Exploration Plans and Development Operations Coordination Documents. We estimat e that burden to average 580 hours per response, including the time for reviewing instructions, gathering and mainta ining data, and completing and reviewing the form. Direct comments regarding the burden estimate or any other aspect of this form to the Information Collection Clearance Officer, Mail Stop 4230, Minerals Management Service, 1849 C Street, N.W., Washington, DC 20240.X = 2,471,040’X = 2,471,040’ Y = 9,868,320’

Y

= 9,852,480’

Y = 9,836,640’X = 2,486,880’X = 2,486,880’



# 867 866 823 822

BP 2

“Parmer” Prospect (Green Canyon 823/867) OCS-G 33854/33858 Surface Location Map
0 2,000’ 1” = 2,000’ 05/20/1 1 Apache Loc. GC 823 A Surface Location

Apache Loc. GC 867 C Surface Location Apache Loc. GC 823 B Surface Location

Apache Loc. GC 867 D Surface Location Apache Loc. GC 867 A Surface Location Apache Loc. GC 823 C Surface Location

Apache Loc. GC 867 B Surface Location 960’ FSL & 7,160’ FWL

of GC 823 X = 2,478,200’ Y = 9,853,440’ Lat. = 27.1304443 Long. = -90.4238109

2,530’ FNL & 3,420’ FWL

of GC 867 X = 2,474,460’ Y = 9,849,950’ Lat. = 27.1210600 Long. = -90.435521 1 1,884’ FSL

& 6,538’ FWL

of GC 823 X = 2,477,578’ Y = 9,854,364’ Lat. = 27.1330196 Long. = -90.4256638

3,752’ FSL & 2,1 10’ FWL

of GC 823 X = 2,473,150’ Y = 9,856,232’ Lat. = 27.1384041 Long. = -90.4391521 27’ FNL & 5,888’ FWL

of GC 867 X = 2,476,928’ Y = 9,852,453’ Lat. = 27.1278025 Long. = -90.4277813

27’ FNL & 5,888’

FWL of GC 867 2,990’ FNL & 5,933’ FWL

of GC 867 X = 2,476,973’ Y = 9,849,490’ Lat. = 27.1 196541 Long. = -90.4278294

1,480’ FNL

& 2,1 10’ FWL

of GC 867 X = 2,473,150’ Y = 9,851,000’ Lat. = 27.1240202 Long. = -90.4394800

AP A GC 823 A AP A GC 823 B AP A GC 867 D

AP A GC 867 A

AP A GC 867 B

AP A GC 867 C AP A GC 823 C

SL SL

SL

SL

SL
SL SL

2,1 10’ FWL

3,420’ FWL 5,933’ FWL1,480’FNL2,530’FNL 2,1 10’ FWL

6,538’ FWL

7,160’ FWL960’FSL BP 12,990’FNL3,752’FSL1,884’FSLX = 2,471,040’X = 2,471,040’ Y = 9,868,320’

Y = 9,852,480’

Y = 9,836,640’X = 2,486,880’X = 2,486,880’



# 867 866 823 822

BP 2
BP 1 AP A GC 867 D

AP A GC 867 B

AP A GC 867 C SL

SL

SL



## -4,300’
-4,300’ -4,200’ -4,200’ -4,100’ -4,000’ -4,200’


### -3,800’

-3,700’ -4,300’ -4,100’ -4,000’ -3,900’ -3,900’ -3,800’ -3,800’ 

## -4,400’ -4,400’ -4,400’

-4,400’ 

### -4,500’



### -5,000’ -4,900’ -4,800’ 

## -4,700’ -4,600’

-5,500’

-5,600’ -5,700’ -5,800’ -5,900’ -5,400’ -5,300’ 

### -5,200’ -5,100’ “Parmer” Prospect (Green Canyon 823/867) OCS-G 33854/33858 Bathymetry Map 0 2,000’ 1” = 2,000’
05/20/1 1 C.I. = 100’ AP A GC 823 A AP A GC 823 B

AP A GC 823 C SL SL

SL
AP A GC 867 A SLOnline Payment 

### Step 3: Confirm Payment 1 | 2 | 3 Thank you. Y our transaction has been successfully completed. Pay.gov Tracking Information Application Name: MMS Exploration Plan - BF Pay.gov Tracking ID: 253N2PBC Agency Tracking ID: 74213057901 Transaction Date and Time: 06/23/2011 17:38 EDT Payment Summary Address Information Account Holder Name: Mariner Energy, Inc. Billing Address: 2000 W. Sam Houston Pkwy, S., Suite 2000 Billing Address 2: City: Houston State / Province: TX Zip / Postal Code: 77042 Country: USA Account Information Card Type: American Express Card Number: ***********3000 Region: Gulf of Mexico
Contact: Terri Young 7132967456 Company Name/No: Apache Deepwater LLC, 03165 Lease Number(s): 33854, 33858, , ,

Area-Block: Green Canyon GC, 823: Green Canyon GC, 867: , : , : , Surface Locations: 7 Payment Information Payment Amount: $24,094.00 Transaction Date and Time: 06/23/2011 17:38 EDT 

### Pa g e 1 of 1 Pa y
. g ov - Online Pa y ment

6/23/2011 htt p s://www. p a y
. g ov/ p a yg ov/ p a y ments/authorizePlasticCardPa y ment.html

### Apache Deepwater LLC Page B-1 Joint Initial Exploration Plan June, 2011 Green Canyon Blocks 823 and 867 (OCS-G 33854 and OCS-G 33858) 

## APPENDIX B GENERAL INFORMATION (A) APPLICATIONS AND PERMITS Listed in the table below are additional permits/a pplications to be file d before operations can commence under this EP: Application/Permit Issuing Agency Status Application(s) for Permit to Drill BOEMRE To be submitted

(B) DRILLING FLUIDS Type of Drilling Fluid Estimated Volume of Drilling Fluid to be Used per Well Water-based – Barite, Sodium Chloride Brine, Salt, Xantham Gum, Poly Plus, Lime, Poly Pac UL, Caustic Soda, Defoam X, Greencide 25g 37,763 bbls.

Oil-based (diesel, mi nerals, oil) 0 bbls Synthetic-based (inter nal olefin, ester) Barite, Suremul, Surewet, Rheflat, Rhethik, Ecotrol RD, Rheduce, Rhebuild, Lime, Calcium Chloride, Vg Plus, Vg Supreme, Calcium Carbonate, G-Seal, Nut Plug, Vinseal 6,026 bbls

(C) NEW OR UNUSUAL TECHNOLOGY Apache Deepwater does not propose to use any new or unusual technology to carry out the proposed explorati on activities. (D) BONDING STATEMENT The bond requirements for the activities and facili ties proposed in this EP are satisfied by a $3,000,000.00 areawide development bond, furnished and maintained according to 30 CFR 256, subpart I; NTL No. 2000-G16, "Guidelines for Ge neral Lease Surety Bonds;" and additional security under 30 CFR 256.53(d) and Natio nal NTL No. 2008-N07, “Supplemental Bond Procedures.”

### Apache Deepwater LLC Page B-2 Joint Initial Exploration Plan June, 2011 Green Canyon Blocks 823 and 867 (OCS-G 33854 and OCS-G 33858) (E) OIL SPILL FINANCIAL RESPONSIBILITY (OSFR) Apache Deepwater LLC, BOEMRE company number 03165, will demonstrate oil spill financial responsibility for the facilities 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". (F) DEEPWATER WELL CONTROL STATEMENT Apache Deepwater LLC, BOEMRE company number 03165, has the financial capability to drill a relief well and conduct other em ergency well control operations. (G) BLOWOUT SCENARIO Estimated maximum flow rate, Green Canyon Block 867 Well Location D: The estimated maximum flow rate would occur in the objective section, if a kick were taken and the well blew out. The maximum Worst Case Disc harge (WCD) modeled for this scenario is 146,302 BOPD. Maximum duration of blowout (days) The duration of the blowout will be a function of the well bridging over, the ability of surface intervention to shut or contain the well or, as a last resort, dr illing a relief well to kill the blowout. The expected maximum time frames fo r uncontrolled flow in each of the different operational outcomes would be as follows:

• Bridging Over In 2 Days,

• Surface Intervention 15 Days

• A Relief Well 41 Days. Maximum discharge volume The following table is a linear estimate of th e maximum discharge volume for each of the aforementioned operational outcomes. Operational

Outcome Maximum Discharge Rate (bbl/day) Discharge Duration

(days) Maximum Discharge Volume (bbl) Bridging Over 146,302 2 292,604 Surface Intervention 146,302 15 2,194,530
Relief Well 146,302 41 5,998,382
Potential of wellbore to bridge over during a blowout There is significant potential for the wellbore to bridge over during the WCD blowout. Bridging is likely to occur due to the extreme drawdown calculated between the formation and the openhole sections. A Merlin reservoir simulati on model was used to investigate the well conditions during the WCD blowout scenario. The estimated reservoir pressure is 8,284 psi. The

### Apache Deepwater LLC Page B-3 Joint Initial Exploration Plan June, 2011 Green Canyon Blocks 823 and 867 (OCS-G 33854 and OCS-G 33858) reservoir model estimated bottomhole flowing pr essures, based upon reservoir properties and flow rates. The calculated drawdown is modeled to be between 574 – 1,275 psi. In our experience in the deepwater GOM, we stri ve to limit the estimated total drawdown on a producing interval to reduce the ri sk of wellbore collapse and sand/ fines migration into a well. We limit the drawdown to less than 1,000 psi by reducing the ra tes the wells produce and by completing each well with a cased hole, frac-pack completion. There is a strong likelihood of wellbore bridging over:

• Drawdown is estimated to be greater than 1,000 psi,

• Blowout occurs in an open hole section of the well, with no benefit of casing or a frac-pack completion,

• If any water zones are exposed this will accelerate wellbore collapse and bridging.

• Wellbore collapse and bridge over under th e conditions cited is estimated not to exceed 2 days. Surface intervention to stop blowout In the event of a blowout and the blowout prevention equipment is still intact, the subsea BOP will be used for successful shut-in of the well. The well would then be killed and re-entered to either abandon or return to normal operations. Surface intervention would be the first line of defense after a blowout occurs. The specific intervention technique chosen will depend on actual conditions and ability to access the existing well. In the event that the subsea BOP is inoperable, the surface intervention would employ the Marine Well Containment Company (MWCC) and/or the Helix Well Contai nment Group (HWCG) containment systems to achieve successful containment of the well. The system will be employed, while simultaneously initiating relief well planning and operations. Specifics will be submitted with the Well Containment Plan. Typically blowouts can be controlled with surf ace intervention, with a good likelihood of success and in a relatively short time frame, as long as , the subsea casing, well head and BOP’s are not damaged beyond use. The intervention technique chosen will depend on actual conditions and ability to access the existing well. There can be simple solutions such as rig up and bullhead kill mud or to more complex solutions, but th e solution will depend on wellbore conditions. Surface intervention time estimate The assumption is that the well has an uncont rolled blowout and the MODU has sunk with displacement from the wellhead. Additionally, it assume s that debris removal will be required to gain access to the subsea BOP system. The ROV has been deployed and was unsuccessful in shutting in the well, using the existing subsea BOP control panel. The scenario employs one of the aforementioned containment system’s ca pping BOP. The following table describes the estimated time required in order to shut in a nd secure the well using the containment system.

### Apache Deepwater LLC Page B-4 Joint Initial Exploration Plan June, 2011 Green Canyon Blocks 823 and 867 (OCS-G 33854 and OCS-G 33858) Operation Duration (hours) Cumulative Time Since Event (days) Assess wellbore conditions for surface intervention requirements. Conduct notifications to the regulatory agencies and primary contractors. 48 2
Site Preparation which includes mobilizing and deployment of the IWOCS system and Dispersant system. 120 5
Debris removal including mobilization of ROV boat and construction support vessel and execution of debris removal plan. 168 7
Well capping operations which include mobilization, deployment, installation and shut-in of the well with the well containment capping stack. 360 15

Note: These operations are occurring c oncurrently during operational phase.

Relief Well It is preferred to drill relief wells from an ope n water location, rather th an a platform location. Open water locations provide the best option on designing a simpler intercept well and allow a greater choice on rig availability. There are not a ny platforms in the vicinity, therefore it is not feasible to consider as a relief well location. Relief well location and drilling strategy The surface location for the reli ef wells would be a function of current, wind direction and wellbore vertical access. The Location D relie f well surface location would be approximately 2,500’ southwest of the well at Location D. The well will be drilled as Build Turn and Ho ld trajectory design to a Target : 45.87° Inc, 15095.42ft MD, 13961.23ft TVD, 2800.13ft VS to set the well up 100’ away from the blowout well and 1000’ above the 13-5/8” casing shoe. The well will then be drilled to intersect the well. Once intersected the well kill pumping operations will be initiated to kill the blowout. The typical relief well Trajectory Design for each location will be very similar to the Location D relief well as follows.

### Apache Deepwater LLC Page B-5 Joint Initial Exploration Plan June, 2011 Green Canyon Blocks 823 and 867 (OCS-G 33854 and OCS-G 33858) Location D Relief Well Trajectory Design Relief well rig availability There are currently eighteen floating rigs in th e US GoM suitable for drilling relief wells at Green Canyon 823/867. The five rigs listed below curren tly have certified BOP systems and are not engaged in well operations.
Rig Name Contractor Rated Water Depth MODU Type Rig Status Ensco 8501 Ensco 8,500 Semisubmersible Standby Ocean Monarch Diamond Offshore 10,000 Semisubmersible Standby
West Sirius Seadrill 10,000 Semisubmersible Standby

### Apache Deepwater LLC Page B-6 Joint Initial Exploration Plan June, 2011 Green Canyon Blocks 823 and 867 (OCS-G 33854 and OCS-G 33858) Maersk Developer Maersk 10,000 Semisubmersible Standby

Danny Adkins Noble 12,000 Semisubmersible Standby

Relief Rig package constraints The proposed rigs for relief well operations have suitable drilling packages with sufficient capabilities to work in the subject water depths of 3,944’ and drill to the required depth of 20000’ TVD or greater. The BOP systems have me t the BOEMRE certifica tion requirements and will be re-inspected in transit, prior to drilling a relief well to the required true vertical depth. Relief well rig contract and mobilization timing Given the current availability of suitable rigs in the GoM, a contract could be finalized in 24-48 hours, after undertaking the d ecision to begin relief well operations. Backup tubulars and wellhead systems are maintained in stock for each well. Mobilization of equipment and services to the rig could be completed in 72 hours, conc urrent with contract execution. The estimated time to move the rig from the current locat ion to the relief we ll location is 32 hours (approximately 106 miles). Duration of relief well Description Hours Cumulative Days Well Control Assessment 48 2.0 Contract & Mobilize Rig & Spud Equipment through 16” Surface Liner. 104 6.3 Set anchors and pin 36” Structural Casing 72 9.3 Spud and drill to the top of the zone of interest and set casing. 521 31 Mag-Range relief well into intersecting position. 120 36 R/U pumping equipment and kill well. 48 41 R/D Pumping Equipment, PA Wellbore, Pull Riser, Pull anchors and Demobilize 251 51

The above time demonstrates the worst case ti ming for all well locations . Specific timing for each well is within 1.5 day of each other.

### Apache Deepwater LLC Page B-7 Joint Initial Exploration Plan June, 2011 Green Canyon Blocks 823 and 867 (OCS-G 33854 and OCS-G 33858) Blowout Prevention and Intervention Summary of prevention measures Apache has maintained a safe track record of prudent operations in the GoM deepwater environment. It will continue to implement its safe operating practices to enhance its operating risk reduction program. In addition to the safe operating practices, the following measures will be implemented into well design, drilling and completion operations.

• BOP Certification, BOP Drills, Pit Drill’s and all other requi red BOEMRE testing requirements,

• Current Well Control Certification for all Drilling and Completion Rig Site Supervisors,

• Taking Slow Pump Rate measurements dur ing all openhole operations and critical cased hole operations,

• Updating Kill Sheets during each tour and posting the same on the rig floor,

• Maintain a current BOP to RKB spaceout Chart,

• Monitoring wellbore fill-ups and displ acements during trips, by the Well Site Supervisor,

• Maintain the necessary circulating swages, TIW Valves and IBOP on the rig floor at all times during operations and function test these valves during each tour. The utilization of Pre-Job Safety meetings will continue to be implemented prior to each operation with all of the rig crew s. These are intended to create a behavior based safety program and promote an atmosphere within the Apache and rig crew interface, such that a “Stop the Job” mentality is promoted across the rig contractors crew, empowering every crew member to question the safety of each operation. Early well control intervention In the event of a blowout situat ion, due to failed BOP equipm ent and uncontrolled flow at the seafloor or at surface, assuming all other surface controlled actuation measures have failed or are inaccessible, an ROV will fly into position at the BOP subsea actuation panel and actuate the shear ram or other appropriate valves, pipe rams and/or annular elements to establish containment. If the riser system and rig have been compromise d, then debris removal will be initiated to obtain clear access to the BOP. A Capping Stack will be employed to achieve successful containment of the well. Once containment is established and wellbore pressure testing and assessment is completed by Apache and Well Control Specialist, we ll kill operations can be initiated through the existing wellbore.
Well control engineering services Apache will have service agreements in pla ce with Wild Well Control and Boots and Coots International Well Control prior to commencement of well operations. In the event of a blowout

### Apache Deepwater LLC Page B-8 Joint Initial Exploration Plan June, 2011 Green Canyon Blocks 823 and 867 (OCS-G 33854 and OCS-G 33858) situation, these companies will be contacted to assist in the detailed design and implementation of well control and/or relief well operations. Additional prevention & mitigation techniques Pursuant to wellbore cementing and zonal isolat ion techniques, all cemen ting operations will be modeled and designed under the gu idelines set forth in API R ecommended Practice 65 Part 1 & 2. Operations will be dictated by the rules and requirements set forth in Federal Regulations, under the wellbore cementing requirements. RP 53 Recommended Practices for Blowout Prev ention Equipment Systems for Drilling Wells and Recommended Practice 16Q for Marine Drilli ng Risers will be used as the guidelines for installation, testing and maintena nce of the surface and subsea Mari ne Risers and BOP systems. The purpose of these recommended practices is to provide information that can serve as a guide for installation and testing of blowout preven tion systems Apache has contracted for floating marine drilling rigs. The goal of using these recommended practices is to assist Apache operations in promoting personnel safety, public safety, integrity of the drilling equi pment and preservation of the environment for floating marine drilling opera tions. These recommended practices help to facilitate the broad availability of prove n, sound engineering and operating practices. These practices are considered acceptable for accomplishing BOP and Marine Riser associated operations. However, equivalent alternative inst allations and practices may be utilized to accomplish the same objectives. Apache when us ing these recommended practices or other alternatives will insure that operations comp ly with requirements of Federal Regulations.

### Apache Deepwater LLC Page C-1 Joint Initial Exploration Plan June, 2011 Green Canyon Blocks 823 and 867 (OCS-G 33854 and OCS-G 33858) 

## APPENDIX C GEOLOGICAL AND GEOPHYSICAL INFORMATION (A) GEOLOGICAL DESCRIPTION Proprietary Information

(B) STRUCTURE CONTOUR MAPS Proprietary Information (C) INTERPRETED 3-D SEISMIC LINES Proprietary Information (D) GEOLOGICAL STRUCTURE CROSS-SECTIONS Proprietary Information (E) SHALLOW HAZARDS REPORT A shallow hazards survey was conducted over Green Canyon Blocks 823 and 867 by Geoscience Earth & Marine Services, Inc. Three copies of the shallow hazard report are being submitted to the BOEMRE under separate cover. (F) SHALLOW HAZARDS ASSESSMENT Utilizing the 3D seismic exploration data, a sh allow hazards assessment was prepared for the proposed surface locations, and is included as Attachment C-4. (G) HIGH-RESOLUTION SEISMIC LINES Proprietary Information (H) STRATIGRAPHIC COLUMN Proprietary Information (I) TIME VS DEPTH TABLES Proprietary Information10615 SHADOW WOOD DRIVE SUITE 200 HOUSTON, TEXAS 77043 Phone: (713) 468

- 1410

Fax: (713) 468

- 1438 E

- mail: gems@gemsinc.com

- 1

- Proposed Well GC 823

- A May 20 , 2011 Project No. 0411

- 1 92 4 Apache Deepwater, LLC 2000 W. Sam Houston Pkwy. South , Suite 1600 Houston , Texas 77042

- 3622
Attention: Mr. John A. Worthen 

### Site Clearance Letter Proposed Wellsite GC 823
- A

Block 823 (OCS
- G
- 33854 ) G re en Canyon Area Gulf of Mexico Apache Deepwater, LLC ( Apache ) plans to drill an exploration well in Block 823 , of the Green Canyon Area ( GC ), Gulf of Mexico. This letter addresses specific seafloor and subsurface geologic conditions to a depth of approximately 1,916 ft below the mudline ( bml ) at the p roposed Wellsite GC 823

- A . The following discussion is based on findings provided within the main body of the geohazard report for Blocks 823 and 867 (GEMS Report No. 0411

- 1924). The surface location for proposed Wellsite GC 823

- A is in the south western quadrant of GC 823. Apache provided the following coordinates: Proposed Wellsite G C 823
- A Spheroid & Datum: Clarke 1866, NAD27 Projection: UTM Zone 1 5 North Line Reference Block Calls X : 2 , 478 , 2 00 ft Latitude: 2 7

. 1304443128059 o N Inline 6781 960 ft F S L Y: 9 , 853 , 44 0 ft Longitude: 9 0

. 4238109104625 ° W Crossline 34082 7,160 ft F W L Apache will drill this well using a moored vessel. An exact anchor pattern for the proposed well location is undetermined at this time. Maps GC 823 A

- 1 through GC 823 A

- 4 show an anchor radius representing a typical maximum length of chain and anchor on bottom is displayed at 10,000 ft from the proposed wellsite. A 1,000 ft buffer zoned beyond the limits of the anchor radius is also included, NTL 2009

- G40 (MMS, 20 09 a ). 

### Attachm ents The maps and figures accompanying this letter have been extracted from the main report’s original maps and 3

- D data volume and centered on the proposed well location. Map GC 823 A

- 1: Bathymetry Map Map GC 823 A

- 2: Seafloor Rendering Map GC 823 A

- 3: Sea floor Amplitude Rendering Map GC 823 A

- 4: Geologic Features Map Figure GC 823 A

- 1: Inline 6781 and Crossline 34082 Showing Condit ions Beneath Proposed Wellsite GC 823

- A Figure GC 823 A

- 2: Tophole Prognosis Chart, Proposed Wellsite GC 823

- A, G reen Canyo n Block 823Project No. 0411

- 1924

- 2

- Proposed Well GC 823

- A 

### NTL Requirements The following report complies with the Bureau of Ocean Energy Management, Regulation, and Enforcement (BOEMRE; formerly the MMS) Notice to Lessees (NTLs) 2008

- G04, 2008

- G05 and 2009

- G40 (MMS, 200 8a, 2008b, and 200 9 a ). The proposed wellsite will be required to follow NTL 2008

- G06 with respect to pre

- and post

- spud ROV visual inspection surveys (MMS, 2008 c ). Pursuant to the recently released Pre

- Seabed Disturbance Survey Mitigation issued by BOEMRE, the 2005

- G07 NT L (MMS, 2005) does not apply to GC 823/867 in terms of high

- probability (MMS, 2008d) , but an archaeological assessment of the data must be performed prior to any bottom disturbing activities (BOEMRE, 2011b)

. According to NTL 2008

- G05 (MMS, 2008b), 3

- D se ismic reflection data may be used for shallow hazard assessments. A power spectrum analysis was conducted from the 3

- D seismic data cube provided by Apache to illustrate the data parameters. The power spectrum curve (below) was generated within a 500

- ft radius of the intersection of the inline and crossline at the proposed wellsite location, over a time interval from the seafloor to ~0.669 second below mudline, i.e., the salt/sediment interface. We converted the amplitude vs. frequency spectrum, generate d by the SMT software, to power vs. frequency by squaring the amplitude values as described by J. A. Coffeen, 1978.

Power Spectrum Analysis Curve, Proposed Wellsite GC 823
- A 

### Man
- Made Features There are existing wells in G C 823 and in surrounding blocks. The closest well to Proposed Wellsite GC 823

- A is the BP Exploration Inc. , GC 823

- 001 well approximately 775 ft to the north

- northeast (Maps GC 823

- A

- 1 through GC 823

- A

- 4). The closest touchdown point for an anchor chain will likely be 2,000 ft from th e proposed wellsite; therefore, the existing site should not be impacted by the proposed mooring pattern. 0 0.2 0.4 0.6 0.8

1 1.2

0 10 20 30 40 50 60 70 80 90 100Power (amp2)

Frequency (hrz) POWER SPECTRUM

GC 823

- AProject No. 0411

- 1924

- 3

- Proposed Well GC 823

- A Other wells near the Proposed Wellsite GC 823

- A are the BP Exploration Inc. , GC 823

- 002 well and GC 866

- 001 wells. These wells are approximately 7,9 00 ft east

- northeast and 10,925 ft west

- southwest, respectively, of the proposed site and lie within the proposed mooring pattern. P roposed Wellsite GC 823

- A and its anchor s lie within the “Military Warning Zone W

- 92 ” . Military warning zones typically d o not have any impact on exploration drilling operations or other oilfield activities. However, notifications to appropriate military commands need to be addressed by Apache (MMS, 2009b) . Restrictions would only be enforced during military operations in the area or during an emergency. 

### Water Depth and Seafloor Conditions T he water depth at the proposed location is

- 4,129 ft (Map GC 823

- A

- 1). The seafloor at the proposed location is slightly irregular and dips to the east

- northeast at about 4.5  ̊. The proposed wellsite is located within a valley between two ridges. The valley occurs along the eastern margin of an extensive topographic high. The topographic high is the seafloor expression of a shallow salt diapir. Water depths within the potential anchor mooring area range from about

- 3,660 ft along a ridge line to the north to approximately

- 4,700 ft on the upper part of the Sigsbee Escarpment to the south (Map GC 823

- A

1). The seafloor within the potential anchoring area varies from smooth and featureless to very irregular. The seafloor irregularities include narrow ridges and gullies, faults, and mounds. Seafloor gradient within the mooring pattern will average from 1° to 5°. The highest seafloor gradients in the area are associated with fault escarpments. G radients of over 20  ̊ are associated with fault scarps that occur primarily north and southwest of the proposed location

. The upper part of the Sigsbee Escarpment to the south will be marked by an increase in slope to 10° to 20°. Near

- surface soils along the Sigsbee Escarpment are likely to be highly overconsolidated and much stronger than typical slope soils. 

### Deepwater Benthic Communities The Seafloor Amplitude Rendering based on the 3

- D data volume (Map GC 823

- A

- 3) shows normal or ambient amplitude along the seabed , with no indication of any hard

- bottom or fluid expulsion events within 2,000 ft of the proposed GC 823

- A location. Based on the renderings and seismic profiles d eepwater benthic communities a re not expected within 2 , 000 ft of the proposed GC 823

- A wellsite. Patches of high

- amplitude seafloor returns occur approximately 8,000 ft to the southwest of the location. The patches are associated with seafloor faults. In addition, the base of a mud mound exists approximately 9,900 ft to the northwest (Maps GC 823

- A

- 1 through GC 823

- A

- 4). These features have a high

- potential for deepwater benthic communities. Therefore, anchors must avoid these features by at least 250 ft (MMS, 2009a). A number of s eafloor faults occur within the proposed mooring pattern. The closest s eafloor faults occur approximately 420 ft to the north

. Except for the faults 8,000 ft to the southwest, n o high

- amplitude returns occur along the seabed escarpments; therefore, proli fic hydrocarbon seepage or carbonate hardgrounds are unlikely

. 

### Stratigraphy Inline 6781 and Crossline 34082 are the closest 3

- D lines to proposed Wellsite GC 823

- A (Figure GC 823

- A

- 1 ). The Tophole Prognosis Chart ( Figure GC 823

- A

- 2 ) shows the inline annotated with calculated depths to the various horizons and predicted lithology of the sequences, along with their potential for shallow water flow and shallow gas. The 3

- D data volume was used to define the sedimentary section to a depth of approximat ely 1 , 916 ft (Figures GC 823

- A

- 1 and GC 823

- A

- 2). The section was divided into four units or sequences (FigureProject No. 0411

- 1924

- 4

- Proposed Well GC 823

- A GC 823

- A

- 1 ). The sequences represent variations in depositional environments and possible changes in soil strength and composition. The surfic ial unit, Unit 1 (Seafloor to Horizon 20 ), to approximately 134 ft bml, consists of a very soft pelagic drape underlain with hemipelagic silty clays and thin, mass

- transport deposits

. Very soft clays with high water content will exist at the seabed. The soils will gradually increase in strength and decrease in water content with depth. Unit 2 (Horizon 20 to Horizon 35) consists of bedded hemipelagic clays and turbidites inter layered with thin chaotic mass

- transport deposits. The sediments will be mud

- ric h; however, some thin sand seams and pockets are possible

. The combined thickness of Units 1 and 2 is approximately 397 ft (Figure GC 823

- A

2 ). Unit 3 (Horizon 35 to Horizon 40) consists of bedded mud

- rich turbidites. The top of Unit 3 , Horizon 35, is at about 397 ft bml. The unit is approximately 394 ft thick beneath GC 823

- A. Unit 4 is a sequence bounded by Horizon 40 and the top of salt ( Figures GC 823

- A

- 1 and GC 823

- A

- 2). The upper portion of the sequence consists of bedded turbidites and thin mass

- transport deposits . The sediments will be alternating clay and silt layers with thin sand or silty sand layers. The unit thins along the flank of the salt structure and reflection continuity is lost. The lower portion of Unit 4 (1,510 ft to 1,916 ft, bm l) is a chaotic interval affected by shallow salt emplacement and will likely consist of a mixture of silts , clays , and sand . Unit 4 occurs between 791 ft and 1,916 ft bml, and is 1,125 ft thick. The top of salt is predicted to be 1,916 ft bml (~6,045 f t bsl). The salt surface dips to the northeast at approximately 40°. 

### Faults Three faults will be intersected by the well bore beneath the proposed Wellsite GC 823

- A (Figure GC 823

- A

- 1). The borehole will intersect the shallowest fault near the base of Unit 2, at approximately 385 ft bml. The remaining deeper faults will be intersected between Horizon 40 and Top of Salt (Unit 4), at depths of about 974 ft and 1,689 ft bml. 

### Shallow Water Flow Unit 2 between Horizons 20 and 3 5 is possibly the regional “ Red Unit ” slope

- fan sequence. However, t he top of the unit is only 134 ft bml at proposed Wellsite GC 823

- A (Figure GC 823

- A

- 2). The entire unit is 263 ft thick. At this location, Unit 2 is an unlikely zone for overpressured sand layers. The existing GC 823

- 001 well is approximately 775 ft to the northeast of the proposed GC 823

- A wellsite. A “low” severity shallow water flow occurred in the GC 823

- 001 well at 1,715 ft bml (

- 5,840 ft bs l). Based on the reported depth the flow occurred in the lower portion of Unit 4 within a generally low

amplitude interval of discontinuous to chaotic reflections (Figure GC 823

- A

- 2). In addition, the interval is bounded by faults that extend from salt t o the seafloor. The shallow water flow may have originated from an isolated sand pocket or layer within the chaotic interval . An alternative explanation is the flow originated in the shallower interval at the top of the unit consisting of bedded, moderat e
- amplitude turbidites

. The flow may not have been observed until drilling was at the 1,715 ft level. Because of the proximity of the GC 823

- 001 well, the lower portion of Unit 4 has been given a high potential for shallow water flow (Figure GC 823

- A

- 2). The upper portion of the unit is given a moderate potential for water flow considering the source of the flow in GC 823

- 001 may have originated higher than when observed during drilling. Sands within the unit are likely to be isolated and faulted. Like GC 823

- 001 any flow will be short

- lived and of low severity. 

### Shallow Gas The well path will not penetrate any high

- amplitude events between the seafloor and the top of salt (Figure GC 823

- A

- 2 ). There is a negligible to low potential for shallow ga s in this section.Project No. 0411

- 1924

- 5

- Proposed Well GC 823

- A 

### Closing The seafloor and near

- surface conditions at Proposed Wellsite GC 823

- A, Green Canyon Block 823 (OCS

G

- 33854 ), appear suitable for exploration drilling operations. The existing wellsites and the potential areas of deepwater benthic communities will need to be avoided by anchors supporting a drilling vessel at the proposed location. Overpressured sand layers are possible within Unit 4

. Sincerely,

GEOSCIENCE EARTH & MARINE SERVICES, INC. ®

Thomas W. Neurauter Ph. D. Daniel Lanier Senior Marine Geologist Vice

- President/Marine Geologist
Attachments ( 4 Maps, 2 Figures) Distribution: M r
. John Worthen , Apache , Houston, TX. ( 6 )

References: Bureau of Ocean Energy Management and Enforcement, 2011a , ASCII Data Files, published on the BOEMRE Gulf of Mexico Region Homepage, <http://www.gomr.mms.gov/homepg/pubinfo/freeasci/freedesc.html>, accessed May , 20 11

. Bureau of Ocean Energy Management, Regulation, and Enforcement , 20 11b, Pre

- Seabed Disturbance S urvey Mitigation < http://www.gomr.boemre.gov/homepg/regulate/environ/archaeological/Conditional

- Archaeological

Mitigation.pdf >. Coffeen, J. A., 1978, Seismic exploration fundamentals: Tulsa, the Petroleum Publishing Co., p. 125. Minerals Management Service , 2005, Notice to lessees and operators of federal oil, gas, and sulphur leases and pipeline right

- of

- way holders in the outer continental shelf, Gulf of Mexico OCS region, Archaeological resource surveys and reports: U. S. Department of the Interior, Min erals Management Service, Gulf of Mexico, NTL 2005

- G07. Minerals Management Service, 2008a, Notice to lessees and operators of federal oil, gas, and sulphur leases in the outer continental shelf, Gulf of Mexico OCS region, information requirements for exploration plans and development operations coordination documents: U. S. Department of the Interior, Minerals Management Service, Gulf of Mexico, NTL 2008

- G04 . Effective Date May 1, 2008. Minerals Management Service, 2008 b , Notice to lessees and operators of federal oil, gas, and sulphur leases and pipeline right

- of

- way holders in the outer continental shelf, Gulf of Mexico OCS region, Shallow hazards requirem ents: U. S. Department of the Interior, Minerals Management Service, Gulf of Mexico, NTL 2008

- G05.Project No. 0411

- 1924

- 6

- Proposed Well GC 823

- A Minerals Management Service, 2008 c , Notice to lessees and operators of federal oil, gas, and sulphur leases in the outer continental shelf, Gulf of Mexico OC S region; remotely operated vehicle surveys in deepwater, U. S. Department of the Interior, Minerals Management Service, Gulf of Mexico, NTL 2008

- G06. Minerals Management Service, 2008 d , Notice to lessees and operators (NTL) of federal oil and gas leases a nd pipeline right

- of

- way (ROW) holders on the outer continental shelf (OCS), Gulf of Mexico OCS region (GOMR), Revisions to the list of OCS lease blocks requiring archaeological resource surveys and reports: U. S. Department of the Interior, Minerals Mana gement Service, Gulf of Mexico, NTL 2008

- G20. Minerals Management Service, 20 09a , Notice to lessees and operators of federal oil and gas leases in the outer continental shelf, Gulf of Mexico OCS region, Deepwater benthic communities: U. S. Department of th e Interior, Minerals Management Service, Gulf of Mexico, NTL 200 9

- G 4 0. Minerals Management Service, 2009b, Notice to lessees and operators of federal oil and gas leases and pipeline right

of

- way holders on the outer continental shelf, Gulf of Mexico OCS re gion, Military Warning and Water Test Areas: U. S. Department of the Interior, Minerals Management Service, Gulf of Mexico, NTL 2009

- G06. Effective Date April 22, 2009.6781.0 33800.0 6781.0 34000.0 6781.0 34200.0 6781.0 34400.0 Line: T race: 15000 20000 25000 30000 35000 40000 1.400

1.500

1.600

1.700

1.800

1.900

2.000

2.100

2.200

2.300

2.400

2.500

2.600

2.700

2.800 Horizontal Distance (ft):

6600.0 34082.0 6800.0 34082.0 7000.0 34082.0 Line: T race: 15000 20000 25000 30000 35000 40000

1.600

1.700

1.800

1.900

2.000

2.100

2.200

2.300

2.400

2.500

2.600

2.700

2.800

2.900 Horizontal Distance (ft): Project No. 041 1-1924 Filename: 1 1 1924_fig_GC823-A-1.cdr



### Figure GC 823-A-1. Inline 6781 and Crossline 34082 Showing Conditions Beneath Proposed W ellsite GC 823-A 15034.839 14132.748 13230.658 12328.568 1 1426.478 10524.387 9622.297 8720.207 7818.1 16 6916.026 6013.936 51 1 1.845 4209.755 3307.665 2405.574 1503.484 601.394 -300.697 -1202.787 -2104.877 -3006.968 -3909.058 -481 1.148 -5713.239 -6615.329 -7517.419 -8419.510 -9321.600 -10223.690 -1 1 125.781 -12027.871 -12929.961 -13832.052 -15034.839RELATIVEAMPLITUDETWO-WAYTIMETRAVEL(SEC)TWO-WAYTIMETRAVEL(SEC) GC 823 GC 867 Northwest Southeast

Inline 6781 SAL T

SAL T GC 823 GC 867 Southwest Northeast

SEAFLOOR HORIZON 20 HORIZON 35 HORIZON 40 T

OP OF SAL T UNIT 1

UNIT 2

UNIT 3 UNIT 4

SEAFLOOR HORIZON 20 HORIZON 35 HORIZON 40

T OP OF SAL T UNIT 1

UNIT 2

UNIT 3

UNIT 4

Crossline 34082 Proposed W ellsite GC 823-A Proposed W ellsite GC 823-A

GC 866 GC 8246781.0 34000.0 6781.0 34200.0 25000 30000 Line: T race:

1.400

1.500

1.600

1.700

1.800

1.900

2.000

2.100

2.200

2.300

2.400

2.500 Horizontal Distance (ft): Shallow W ater Flow and Gas Potential HIGH 0 1 2 3 0 = NEGLIGIBLE 1 = LOW 2 = MODERA

TE 3 = HIGH NEGLIGIBLE



### Figure GC 823-A-2. T

ophole Prognosis Chart, Proposed W ellsite A, Green Canyon Block 823 Filename: 1 1 1924_fig_GC823-A-2.cdr Project No. 041 1-1924
3-D Seismic Section Through Proposed W ellsite A X = 2,478,200 FT; Y

= 9,853,440 FT Crossline 34082 at Inline 6781 NW SE

Inline 6781 GC 823 PROPOSED WELLSITE ATWO-WAYTRAVELTIME (SEC) GC 867

SEAFLOOR W ater Flow GasUnit 1 HORIZON 20

HORIZON 40

F AUL T

T OP OF SAL TUnit 2Unit 4 1.685

1.736

INTERF ACE 1.975

2.280

2.353 -4,129

-4,263

-4,920

-5,818

-6,045 134

791

1,689

1,916 134

394

1,125 Seafloor Slopes at 4.5° East-Northeast

Lithology/Stratigraphy W A TER FLOW AND GAS POTENTIAL Horizon Horizon TWT (sec, bsl) Depth

(ft, bsl) Depth (ft, bml)Units Unit

(Interval) Thickness (ft)Unit 3 Potential Drilling Constraints

F AUL T 2.039 -5,103 974 F AUL T 1.829 -4,515 385 HORIZON 35 1.833 -4,527 397 263

2.221 -5,639 1,510 V ery soft, pelagic drape at seafloor . Hemipelagic silty clays and thin mass-transport deposits. Alternating layers of hemipelagic silty clays with chaotic mass-transport deposits. Fault at very base of unit.

Mud-rich turbidites.

T urbidites. Alternating layers of clay and silt with thin sands. Fault near top of unit.

Chaotic sequence created by salt movement. Fault near base of unit. Negligible potential for overpressured sands. Negligible potential for shallow gas.
Negligible potential for overpressured sands. Negligible potential for shallow gas.

Low potential for overpressured sands. Low potential for shallow gas.

W ater Flow reported in Unit 4 at GC 823-001 well, 775 ft to Northeast. Moderate potential for overpressured sands. Low potential for shallow gas.

T op of salt slopes 40 ° to Northeast. .

High potential for overpressured sands. Low potential for shallow gas. Faults are possible zones of loss circulation.

SAL T

TROUGH PEAK RELA TIVE AMPLITUDE10615 SHADOW WOOD DRIVE SUITE 200 HOUSTON, TEXAS 77043 Phone: (713) 468

- 1410

Fax: (713) 468

- 1438 E

- mail: gems@gemsinc.com

- 1

- Proposed Well GC 823

- B May 20 , 2011 Project No. 0411

- 1 92 4 Apache Deepwater, LLC 2000 W. Sam Houston Pkwy. South , Suite 1600 Houston , Texas 77042

- 3622
Attention: Mr. John A. Worthen 

### Site Clearance Letter Proposed Wellsite GC 823
- B

Block 823 (OCS
- G
- 33854 ) Green Canyon Area Gulf of Mexico Apache Deepwater, LLC ( Apache ) plans to drill an exploration well in Block 823 , of the G re en Canyon Area ( G C ), Gulf of Mexico. This letter addresses specific seafloor and subsurface geologic conditions to a depth of approximately 2 , 010 ft below the mudline ( bml ) at the Proposed Exploration Wellsite GC 823

- B

. The following discussion is based on findings provided within the main body of the geohazard report for Block 823 ( GEMS Report No. 0411

- 1 92 4) . The surface location for Proposed Wellsite GC 823

- B is in the south western quadrant of G C 823

. Apache provided the following coordinates: Proposed Wellsite G C 823
- B Spheroid & Datum: Clarke 1866, NAD27 Projection: UTM Zone 15 North Line Reference Block Calls X : 2 , 477 , 578 ft Latitude: 27. 1330196394346 o N Inline 6784 1 ,8 84 ft F S L Y: 9 , 85 4, 364 ft Longitude: 9 0

. 4256637928309 ° W Crossline 34109 6,538 ft F W L Apache will drill this well using a moored vessel. An exact anchor pattern for the proposed well location is undetermined at this time. Maps GC 823

- B

- 1 through GC 823

- B

- 4 show an anchor radius representing a typical maximum length of chain and anchor on bottom is displayed at 10,000 ft from the proposed wellsite. A 1,000 ft buffer zoned beyond the limits of the anchor radius is also included, NTL 200 9

- G40 (MMS, 2009 a ). 

### Attachments The maps and figures accompanying this letter have been extracted from the main report’s original maps and 3

- D data volume and centered on the proposed well location. Map GC 823

- B

- 1: Bathymetry Map Map GC 823

- B

- 2: Seafloo r Rendering Map GC 823

- B

- 3: Seafloor Amplitude Rendering Map GC 823

- B

- 4: Geologic Features Map Figure GC 823

- B

- 1: Inline 6784 and Crossline 34109 Showing Condit ions Beneath Proposed Wellsite GC 823

- B Figure GC 823

- B

- 2: Tophole Prognosis Chart, Proposed Wellsite GC 823

- B , G re en Canyon 823Project No. 0411

- 1924

- 2

- Proposed Well GC 823

- B 

### NTL Requirements The following report complies with the Bureau of Ocean Energy Management, Regulation, and Enforcement (BOEMRE; formerly the MMS) Notice to Lessees (NTLs) 2008

- G04, 2008

- G05 and 2009

- G40 (MMS, 200 8a, 2008b, and 200 9 a ). The proposed wellsite will be required to follow NTL 2008

- G06 with respect to pre
- and post

- spud ROV visual inspection surveys (MMS, 2008 c ). Pursuant to the recentl y released Pre

Seabed Disturbance Survey Mitigation issued by BOEMRE, the 2005

- G07 NTL (MMS, 2005) does not apply to GC 823 in terms of high

- probability (MMS, 2008d) , but an archaeological assessment of the data must be performed prior to any bottom distur bing activities (BOEMRE, 2011b)

. According to NTL 2008

- G05 (MMS, 2008b), 3

- D seismic reflection data may be used for shallow hazard assessments. A power spectrum analysis was conducted from the 3

- D seismic data cube provided by Apache to illustrate the data parameters. The power spectrum curve (below) was generated within a 500

- ft radius of the intersection of the inline and crossline at the proposed wellsite location, over a time interval from the seafloor to ~0.699 second below mudline, i.e., the salt /sediment interface. We converted the amplitude vs. frequency spectrum, generated by the SMT software, to power vs. frequency by squaring the amplitude values as described by J. A. Coffeen, 1978.

Power Spectrum Analysis Curve, Proposed Wellsite G C 82 3
- B 

### Man
- Made Features There are existing wells in G C 823 and in surrounding blocks. The closest well to Proposed Wellsite GC 823

- B is the BP Exploration Inc. , GC 823

- 001 well approximately 820 ft to the east

- southeast (Maps GC 823

- B

- 1 through GC 823

- B

- 4). The closest touchdown point for an anchor chain will probably be 2,000 ft from the proposed wellsite; therefore, the existing site should not be impacted by the proposed mooring pattern. 0 0.2 0.4 0.6 0.8

1 1.2

0 10 20 30 40 50 60 70 80 90 100Power (amp2)

Frequency (hrz) POWER SPECTRUM

GC 823

- BProject No. 0411

- 1924

- 3

- Proposed Well GC 823

- B Other wells near the Proposed Wellsite GC 823

- B are the BP Ex ploration Inc. , GC 823

- 002 and GC 866

- 001 wells. These wells are approximately 8,400 ft east and 10,700 ft southwest, respectively, of the proposed site and lie within the proposed mooring pattern. Proposed Wellsite GC 823

- B and its anchors lie within the “Military Warning Zone W

- 92 ”. Military warning zones typically do not have any impact on exploration drilling operations or other oilfield activities. However, some permitting issues and/or notifications to appropriate military commands need to be addre ssed by Apache (MMS, 2009b). Restrictions would only be enforced during military operations in the area or during an emergency. 

### Water Depth and Seafloor Conditions T he water depth at the proposed location is

- 4,072 ft (Map GC 823

- B

- 1). The seafloor at the proposed location is slightly irregular and dips to the east at about 2.8  ̊. The proposed wellsite occurs in a valley between two ridges (Map GC 823

- B

- 2). This area is along the eastern margin of a large topographic high created by a salt diapir. Water depths within the potential anchor mooring area range from about

- 3,660 ft along a ridge line to the north to approximately

- 4, 5 00 ft on the upper part of the Sigsbee Escarpment to the south (Map GC 823

- B

1). The seafloor within the potential anchoring area varies from smooth and featureless to very irregular. The seafloor irregularities include narrow ridges and gullies, faults, and mounds. Seafloor gradient within the mooring pattern will average from 1° to 5°. The highest seafl oor gradients in the area are associated with fault escarpments. Gradients of over 20  ̊ are associated with fault scarps that occur primarily north and southwest of the proposed location . The upper part of the Sigsbee Escarpment to the south will be marke d by an increase in slope from 10° to 20°. Near

- surface soils along the Sigsbee Escarpment are likely to be highly overconsolidated and much stronger than typical slope soils. 

### Deepwater Benthic Communities The Seafloor Amplitude Rendering based on the 3

- D data volume (Map GC 823

- B

- 3) shows normal or ambient amplitude along the seabed, with no indication of any hard

- bottom or fluid expulsion events within 2,000 ft of the proposed GC 823

- B location. Based on the renderings and seismic profiles d eepwater ben thic communities are not expected within 2,000 ft of the proposed GC 823

- B wellsite. Patches of high

- amplitude seafloor returns occur approximately 9,300 ft to the southwest of the location. The patches are associated with seafloor faults. In addition, the base of a mud mound exists approximately 9,400 ft to the northwest (Maps GC 823

- B

- 1 through GC 823

- B

- 4). These features have a high

- potential for deepwater benthic communities. Therefore, anchors must avoid these features by at least 250 ft (MMS, 200 9a). A number of seafloor faults occur within the proposed mooring pattern. The closest seafloor fault occur s approximately 275 ft to the south

- southwest . Except for the faults 9,300 ft to the southwest, no high

amplitude returns occur along the seabed escarpments; therefore, prolific hydrocarbon seepage or carbonate hardgrounds are unlikely. 

### Stratigraphy Inline 6784 and Crossline 34109 are the closest 3

- D lines to proposed Wellsite GC 823

- B (Figure GC 823

- B

1 ). The Tophole Prognosis Chart (Figure GC 823

- B

- 2 ) shows the crossline annotated with calculated depths to the various horizons and predicted lithology of the sequences, along with their potential for shallow water flow and shallow gas. The 3

- D data volume was used to define the sedimentary section to a depth of approximately 2,010 ft (Figure GC 823

- B

- 2). The section was divided into four units or sequences (Figure GC 823

- B

- 1 ). The sequences re present variations in depositional environments and possible changes in soil strength and composition.Project No. 0411

- 1924

- 4

- Proposed Well GC 823

- B The surficial unit, Unit 1 (Seafloor to Horizon 20 ), to approximately 135 ft bml, consists of a very soft pelagic drape underlain with hemipelagic silty clays and thin, mass

- transport deposits

. Very soft clays with high water content will exist at the seabed. The soils will gradually increase in strength and decrease in water content with depth. Unit 2 (Horizon 20 to Horizon 35) consists of bedded hemip elagic clays and turbidites interlayered with thin chaotic mass

- transport deposits. The sediments will be mud

- rich; however, some thin sand seams and pockets are possible. The combined thickness of Units 1 and 2 is approximately 518 ft (Figure GC 823

- B

- 2). Unit 3 (Horizon 35 to Horizon 40) consists of mud

- rich turbidites. The top of Unit 3, Horizon 35, is at about 518 ft bml. The sequence is approximately 3 12 ft thick at proposed location GC 823

- B. Unit 4 is a sequence bounded by Horizon 40 and the t op of salt (Figures GC 823

- B

- 1 and GC 823

- B

- 2). The upper portion of the sequence consists of bedded turbidites and thin mass

- transport deposits. The sediments will be alternating clay and silt layers with thin sand or silty sand layers. The unit thins along the flank of the salt structure and reflection continuity is lost. The lower portion of Unit 4 (1,367 ft to 2,010 ft, bml) is a chaotic interval affected by shallow salt emplacement and will likely consist of a mixture of silt, clay, and sand. Unit 4 occurs between 830 ft and 2,010 ft bml, and is 1,180 ft thick. The top of salt is predicted to be 2,010 ft bml (~6,082 ft bsl). The salt surface dips to the east

- northeast at approximately 41°. 

### Faults Two faults will be intersected by the well bore beneath proposed Wellsite GC 823

- B (Figure s GC 823

- B

- 1 and GC 823

- B

- 2 ). The borehole will intersect the shallowest fault at approximately 466 ft bml, near the base of Unit 2. The remaining fault will be intersected between Horizon 40 and Top of Salt (Uni t 4), at a depth of about 1,160 ft bml. 

### Shallow Water Flow Unit 2 between Horizons 20 and 35 is possibly the regional “Red Unit” slope

- fan sequence. However, the top of the unit is only 135 ft bml at proposed Wellsite GC 823

- B (Figure GC 823

- B

- 2). The entire unit is 383 ft thick. At this location, Unit 2 is an unlikely zone for overpressured sand layers. The existing GC 823

- 001 well is approximately 820 ft to the east

- southeast of the proposed GC 823

- B wellsite. A “low” severity shallow water flow occurred in the GC 823

- 001 well at 1,715 ft bml (

- 5,840 ft bsl). Based on the reported depth the flow occurred in the lower portion of Unit 4 within a generally low

amplitude interval of discontinuous to cha otic reflections (Figure GC 823

- B

- 2). In addition, the interval is bounded by faults that extend from salt to the seafloor. The shallow water flow may have originated from an isolated sand pocket or layer within the chaotic interval. An alternative expl anation is the flow originated in the shallower interval at the top of the unit consisting of bedded, moderate

- amplitude turbidites. The flow may not have been observed until drilling was at the 1,715 ft level. Because of the proximity of the GC 823

- 001 well, the lower portion of Unit 4 has been given a high potential for shallow water flow (Figure GC 823

- B

- 2). The upper portion of the unit is given a moderate potential for water flow considering the source of t he flow in GC 823

- 001 may have originated higher than when observed during drilling. Sands within the unit are likely to be isolated and faulted. Like GC 823

- 001 any flow will be short

- lived and of low severity. 

### Shallow Gas The well path will not penetr ate any high

- amplitude events between the seafloor and the top of salt (Figure GC 823

- B

- 2). There is a negligible to low potential for shallow gas in this section. 

### Closing The seafloor and near

- surface conditions at p roposed Wellsite GC 823

- B , Green Canyo n Block 823 (OCS

G

- 33854 ), appear suitable for exploration drilling operations. The existing wellsites and the areas ofProject No. 0411

- 1924

- 5

- Proposed Well GC 823

- B potential deepwater benthic communities will need to be avoided by anchors supporting a drilling vessel at the proposed location. Over pressured sand layers are possible within Unit 4. Sincerely,

GEOSCIENCE EARTH & MARINE SERVICES, INC. ®

Thomas W. Neurauter Ph. D. Daniel Lanier Senior Marine Geologist Vice

- President/Marine Geologist

Attachments ( 4 Maps, 2 Figures) Distribution: Mr

. John Worthen , Apache Deepwater, LLC , Houston, TX. ( 6 ) References: Bureau of Ocean Energy Management and Enforcement, 2011a , ASCII Data Files, published on the BOEMRE Gulf of Mexico Region Homepage, <http://www.gomr.mms.gov/homepg/pubinfo/ freeasci/freedesc.html>, accessed May , 20 11

. Bureau of Ocean Energy Management, Regulation, and Enforcement , 20 11b, Pre

- Seabed Disturbance Survey Mitigation < http://www.gomr.boemre.gov/homepg/regulate/environ/archaeological/Conditional

- Archaeological

Mitig ation.pdf >. Coffeen, J. A., 1978, Seismic exploration fundamentals: Tulsa, the Petroleum Publishing Co., p. 125. Minerals Management Service, 2005, Notice to lessees and operators of federal oil, gas, and sulphur leases and pipeline right

- of

- way holders in the outer continental shelf, Gulf of Mexico OCS region, Archaeological resource surveys and reports: U. S. Department of the Interior, Minerals Management Service, Gulf of Mexico, NTL 2005

- G07. Minerals Managem ent Service, 2008a, Notice to lessees and operators of federal oil, gas, and sulphur leases in the outer continental shelf, Gulf of Mexico OCS region, information requirements for exploration plans and development operations coordination documents: U. S. D epartment of the Interior, Minerals Management Service, Gulf of Mexico, NTL 2008

- G04. Effective Date May 1, 2008. Minerals Management Service, 2008 b , Notice to lessees and operators of federal oil, gas, and sulphur leases and pipeline right

- of

- way holders in the outer continental shelf, Gulf of Mexico OCS region, Shallow hazards requirements: U. S. Department of the Interior, Minerals Management Service, Gulf of Mexico, NTL 2008

- G05. Minerals Management Service, 2008 c , Notice to lessees and operators of federal oil, gas, and sulphur leases in the outer continental shelf, Gulf of Mexico OCS region; remotely operated vehicle surveys in deepwater, U. S. Department of the Interior, Minerals Management Service, Gulf of Mexi co, NTL 2008

- G06. Minerals Management Service, 2008 d , Notice to lessees and operators (NTL) of federal oil and gas leases and pipeline right

- of

- way (ROW) holders on the outer continental shelf (OCS), Gulf of Mexico OCS region (GOMR), Revisions to the list of OCS lease blocks requiring archaeological resource surveys and reports: U. S. Department of the Interior, Minerals Management Service, Gulf of Mexico, NTL 2008

- G20. Minerals Management Service, 20 09a , Notice to lessees and operators of federal oil and gas leases in the outer continental shelf, Gulf of Mexico OCS region, Deepwater benthic communities: U. S. Department of the Interior, Minerals Management Service, Gulf of Mexico, NTL 200 9

- G 4 0.Project No. 0411

- 1924

- 6

- Proposed Well GC 823

- B Minerals Management Service, 2009b, Notice to lessees and oper ators of federal oil and gas leases and pipeline right

- of

way holders on the outer continental shelf, Gulf of Mexico OCS region, Military Warning and Water Test Areas: U. S. Department of the Interior, Minerals Management Service, Gulf of Mexico, NTL 2009

- G06. Effective Date April 22, 2009.