UNITED STATES GOVERNMENT MEMORANDUM

To: Public Information (MS 5030)

Plans Section, Office of Field 

Operations (MS 5231)

Public Information copy of Exploration Plan

Control # - R-05906

Type - Revised Exploration Plan

Lease(s) - OCS-G31613 Block - 213 Garden Banks Area

OCS- Block - 169 Garden Banks Area

Operator - Apache Deepwater LLC

Subsea Wells A, B, and C

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:

September 5, 2013
PUBLIC COPY 

RECORD OF CHANGES

Operator: Apache Deepwater LLC 

Lease: OCS-G 31613 

Area/Block: Garden Banks Block 213 

Plan Type: Revised Initial Exploration Plan 

Plan Control No.: R-5906 

Complete Plan Submitted: August 21, 2013 

BOEM Coordinator: Michelle Griffitt 

Date Appendix Page Revision 

7/1/13 H 1 Add statement regarding 

submittal/verification of the WCS for the 

Regional OSRP to the Proprietary and Public 

Copies 

7/17/13 H Provide Apache’s Merlin/Avalon Software 

version 

E 1 Revised statement due to anchor radius is 

around numerous potentially sensitive 

biological features 

8/13/13 H WCD revision submitted also with revised 

.nod/.mer files 
REVISED INITIAL EXPLORATION PLAN 

PUBLIC COPY 

August 21, 2013 

Area/Block: Garden Banks Block 213 

Lease Number(s): OCS-G 31613 

Prospect Name: Bimini 

Offshore: Louisiana 

Prepared By: 

Ms. Terri Young 

Apache Deepwater LLC 

2000 W. Sam Houston Pkwy. S., Suite 1600 

Houston, Texas 77042 

(713) 296-7456 

Terri.young@apachecorp.com

Plan No.: R-5906 

Assigned to: Michelle Griffitt 

Date of Submittal: August 21, 2013 

Estimated Start-up Date: January 3, 2014 
REVISED INITIAL EXPLORATION PLAN 

LEASE OCS-G 31613 

GARDEN BANKS BLOCK 213 

TABLE OF CONTENTS 

SECTION A Plan Contents

SECTION B General Information

SECTION C Geological, Geophysical Information

SECTION D H2S Information

SECTION E Biological, Physical and Socioeconomic Information

SECTION F Wastes and Discharge Information

SECTION G Air Emissions Information

SECTION H Oil Spills Information

SECTION I Environmental Monitoring Information

SECTION J Lease Stipulations Information

SECTION K Environmental Mitigation Measures Information

SECTION L Support Vessels and Aircraft Information

SECTION M Onshore Support Facilities Information

SECTION N Coastal Zone Management Act (CZMA) Information

SECTION O Environmental Impact Analysis

SECTION 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 (Not Required) 

C-4 Shallow Hazard Assessment 

F-1 Projected Generated Wastes 

G-1 AQR Worksheets 

H-2 Spill Response Discussion for NEPA Analysis 

L-1 Solid and Liquid Waste Transportation 

L-2 Vicinity Map 

N-1 Coastal Zone Management Consistency Certification 

O-1 Environmental Impact Analysis 
Apache Deepwater LLC	 	 Page A‐1

Revised Initial Exploration Plan	 	 August 20, 2013

Garden Banks Block 213 (OCS‐G 31613)	 	

SECTION A 

PLAN CONTENTS 

(30 CFR 550.211 and 550.241) 

A. PLAN INFORMATION FORM

Apache Deepwater LLC submits this Revised Initial Exploration Plan to propose the drill and 

completion of three (3) well locations, Garden Banks Block 213. The revisions include adding 

the rig type, DP Semi-Submersible along with the Semi-Submersible. These revisions will 

comply with the NTL 2010-N06 and the December 13, 2010 Guidance. The Initial EP, Plan No. 

9283 was approved January 5, 2009. Tentative schedules from start to finish of the drilling and 

completion activities and information regarding the proposed locations are included on the OCS 

Plan Information Form BOEM-0137, included as Attachment A-1.

Apache Deepwater is submitting Right-of-Use and Easement for the three (3) surface locations 

in Garden Banks Block 169 (expired November 30, 2007 via OWL Database). The RUE will be 

filed in conjunction with this Revised Initial Exploration Plan. 

B. LOCATION 

A Well Location Map depicting the proposed surface locations for the proposed wells is included 

as Attachment A-2. A Bathymetry Map showing the water depths across the lease block is 

included as Attachment A-3. These attachments are in accordance with the Notice to Lessees 

(NTL) 2010-N06, Information Requirements for Exploration Plans, Development and 

Production Plans and Development Operations Coordination Documents on the OCS. 

C. SAFETY AND POLLUTION PREVENTION FEATURES 

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

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

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

prevention equipment as described in Title 30 CFR Part 550, Subparts C, D, E and F; and as 

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

Environmental Protection Agency and the U.S. Coast Guard. 

Appropriate life rafts, life jackets, ring buoys, etc., will be maintained on the facility at all times 

as mandated by the U.S. Coast Guard regulations contained in Title 33 CFR. 

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

Revised Initial Exploration Plan	 	 August 20, 2013

Garden Banks Block 213 (OCS‐G 31613)	 	

D. STORAGE TANKS AND/OR PRODUCTION VESSELS 

The Garden Banks Block 213 wells will be drilled with a Semisubmersible or DP 

Semisubmersible unit. All facility tanks of 25 barrels or more. 

Type of 

Storage Tank 

Type of 

Facility (Rig) 

Tank 

Capacity 

(bbls) 

Number 

of 

Tanks 

Total 

Capacity 

(bbls) 

Fluid 

Gravity 

(APIDegree) 

Fuel Oil (Marine Diesel) Semisubmersible 105 1 105 35° 

Fuel Oil Day Semisubmersible 98 1 98 35° 

Emergency Generator Semisubmersible 5.5 1 5.5 35° 

Forward Hull – Fuel Oil Semisubmersible 3,416 1 3,416 35° 

Lower AFT Hull – Fuel Oil Semisubmersible 3,416 1 3,416 35° 

Lube Oil Services Semisubmersible 61 7 427 26° 

Dirty Lube Oil Semisubmersible 30 1 30 26° 

Dirty Bilge Semisubmersible N/A N/A N/A N/A 

Fuel Oil (Marine Diesel) DP Semisubmersible 164 1 164 35° 

Fuel Oil Day DP Semisubmersible 262 1 262 35° 

Emergency Generator DP Semisubmersible 31 1 31 35° 

Forward Hull – Fuel Oil DP Semisubmersible 4,541 2 9,082 35° 

Lower AFT Hull – Fuel Oil DP Semisubmersible 6,790 2 13,580 35° 

Lube Oil Services DP Semisubmersible 115 1 115 26° 

Dirty Lube Oil DP Semisubmersible 33 2 66 26° 

Dirty Bilge DP Semisubmersible N/A N/A N/A N/A 

E. ADDITIONAL MEASURES 

Apache Deepwater does not propose additional safety, pollution prevention or early spill 

detection measures beyond those required by 30 CFR 550. 

F. COST RECOVERY FEE 

No cost recover fees are associated with this revised initial exploration plan. 
U.S. Department of the Interior OMB Control Number: 1010-0151

Bureau of Ocean Energy Management OMB Approval Expires: 12/31/14

OCS PLAN INFORMATION FORM 

General Information 

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Project and Worst Case Discharge (WCD) Information

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Description of Proposed Activities and Tentative Schedule (Mark all that apply) 

Proposed Activity Start Date End Date No. of Days 

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Description of Drilling Rig Description of Structure 

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Description of Lease Term Pipelines 

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

Form BOEM- 0137 (December 2011- Supersedes all previous editions of this form which may not be used.) Page 1 of 4

ATTACHMENT A-1

GB 213 A

GB 213 B

GB 213 C

X Revised

Apache Deepwater LLC 03165

Terri Young

2000 W. Sam Houston Pkwy, South, Ste. 1600 713-296-7456

Houston, TX 77042 terri.young@apachecorp.com

NA NA

OCS-G 31613 GB 213 Bimini

X Port Fourchon

395,611 36

113 395,611

X

N-09283 Approved 1/5/2009

X

X

X

1/3/2014 4/9/2014 96

1/3/2015 4/9/2015 96

1/3/2016 4/9/2016 96

X

X
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): 

Previously reviewed under an approved EP or 

DOCD? 

Yes No 

Is this an existing well 

or structure? 

Yes No If this is an existing well or structure, list the 

Complex ID or API No. 

Do you plan to use a subsea BOP or a surface BOP on a floating facility to conduct your proposed activities? Yes No 

WCD info For wells, volume of uncontrolled 

blowout (Bbls/day): 

For structures, volume of all storage and 

pipelines (Bbls):

API Gravity of 

fluid

Surface Location Bottom-Hole Location (For Wells) Completion (For multiple completions, 

enter separate lines) 

Lease No. OCS OCS OCS

OCS

Area Name 

Block No. 

Blockline

Departures 

(in feet)

N/S Departure: F____ L N/S Departure: F____ L N/S Departure: F____ L

N/S Departure: F____ L 

N/S Departure: F____ L 

E/W Departure: F____ L E/W Departure: F____ L E/W Departure: F____ L 

E/W Departure: F____ L 

E/W Departure: F____ L 

Lambert XY

coordinates 

X: X: X: 

X:

X:

Y: Y: Y:

Y:

Y:

Latitude/

Longitude

Latitude Latitude Latitude 

Latitude

Latitude

Longitude Longitude Longitude 

Longitude

Longitude

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

Anchor Radius (if applicable) in feet: 

MD (Feet): 

MD (Feet): 

MD (Feet): 

TVD (Feet): 

TVD (Feet): 

TVD (Feet): 

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

Anchor Name 

 or No. 

Area Block X Coordinate Y Coordinate Length of Anchor Chain on Seafloor 

X = Y = 

X = Y = 

X = Y = 

X = Y = 

X = Y = 

X = Y = 

X = Y = 

X = Y = 

Form BOEM- 0137 (December 2011- Supersedes all previous editions of this form which may not be used.) Page 2 of 4

A X

X

X

Expired - RUE Submittal

Garden Banks

169

S

3,155' W

655'

1,917,295'

10,093,235'

27.8113111

-92.1431972

919'

5,946'
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): 

Previously reviewed under an approved EP or 

DOCD? 

Yes No 

Is this an existing well 

or structure? 

Yes No If this is an existing well or structure, list the 

Complex ID or API No. 

Do you plan to use a subsea BOP or a surface BOP on a floating facility to conduct your proposed activities? Yes No 

WCD info For wells, volume of uncontrolled 

blowout (Bbls/day): 

For structures, volume of all storage and 

pipelines (Bbls):

API Gravity of 

fluid

Surface Location Bottom-Hole Location (For Wells) Completion (For multiple completions, 

enter separate lines) 

Lease No. OCS OCS OCS

OCS

Area Name 

Block No. 

Blockline

Departures 

(in feet)

N/S Departure: F____ L N/S Departure: F____ L N/S Departure: F____ L

N/S Departure: F____ L 

N/S Departure: F____ L 

E/W Departure: F____ L E/W Departure: F____ L E/W Departure: F____ L 

E/W Departure: F____ L 

E/W Departure: F____ L 

Lambert XY

coordinates 

X: X: X: 

X:

X:

Y: Y: Y:

Y:

Y:

Latitude/

Longitude

Latitude Latitude Latitude 

Latitude

Latitude

Longitude Longitude Longitude 

Longitude

Longitude

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

Anchor Radius (if applicable) in feet: 

MD (Feet): 

MD (Feet): 

MD (Feet): 

TVD (Feet): 

TVD (Feet): 

TVD (Feet): 

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

Anchor Name 

 or No. 

Area Block X Coordinate Y Coordinate Length of Anchor Chain on Seafloor 

X = Y = 

X = Y = 

X = Y = 

X = Y = 

X = Y = 

X = Y = 

X = Y = 

X = Y = 

Form BOEM- 0137 (December 2011- Supersedes all previous editions of this form which may not be used.) Page 2 of 4

B X

X

X

Expired - RUE Submittal

Garden Banks

169

S

3,520' W

1,797'

1,918,437'

10,093,600'

27.8122934

-92.1396557

923'

5,966'
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): 

Previously reviewed under an approved EP or 

DOCD? 

Yes No 

Is this an existing well 

or structure? 

Yes No If this is an existing well or structure, list the 

Complex ID or API No. 

Do you plan to use a subsea BOP or a surface BOP on a floating facility to conduct your proposed activities? Yes No 

WCD info For wells, volume of uncontrolled 

blowout (Bbls/day): 

For structures, volume of all storage and 

pipelines (Bbls):

API Gravity of 

fluid

Surface Location Bottom-Hole Location (For Wells) Completion (For multiple completions, 

enter separate lines) 

Lease No. OCS OCS OCS

OCS

Area Name 

Block No. 

Blockline

Departures 

(in feet)

N/S Departure: F____ L N/S Departure: F____ L N/S Departure: F____ L

N/S Departure: F____ L 

N/S Departure: F____ L 

E/W Departure: F____ L E/W Departure: F____ L E/W Departure: F____ L 

E/W Departure: F____ L 

E/W Departure: F____ L 

Lambert XY

coordinates 

X: X: X: 

X:

X:

Y: Y: Y:

Y:

Y:

Latitude/

Longitude

Latitude Latitude Latitude 

Latitude

Latitude

Longitude Longitude Longitude 

Longitude

Longitude

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

Anchor Radius (if applicable) in feet: 

MD (Feet): 

MD (Feet): 

MD (Feet): 

TVD (Feet): 

TVD (Feet): 

TVD (Feet): 

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

Anchor Name 

 or No. 

Area Block X Coordinate Y Coordinate Length of Anchor Chain on Seafloor 

X = Y = 

X = Y = 

X = Y = 

X = Y = 

X = Y = 

X = Y = 

X = Y = 

X = Y = 

Form BOEM- 0137 (December 2011- Supersedes all previous editions of this form which may not be used.) Page 2 of 4

C X

X

X

36

Expired - RUE Submittal

Garden Banks

169

S

1,650' W

3,500'

1,920,140'

10,091,730'

27.8071153

-92.1344270

821'

4,867'

423,942
Y = 10,090,080'

Y = 10,074,240'

Y = 10,058,400'

X = 1,916,640'

X = 1,932,480'

212 213 214

168

256

169 170

257 258

British-Borneo

1

APA

Loc.

“A”

APA

Loc.

“B”

APA

Loc.

“C”

SL

SL

SL

Loc. A (SL)

3,155' FSL

655' FWL

Loc C (SL)

1,650' FSL

3,500' FWL

Loc. B (SL)

3,520' FSL

1,797' FWL

Surface Location Map

1" = 4000'

APACHE DEEPWATER, LLC

Garden Banks 213

OCS-G 31613 

Apache Loc. GB 213 A

Surface Location

Apache Loc. GB 213 B

Surface Location

Apache Loc. GB 213 C

Surface Location

3,155' FSL & 655' FWL of GB 169

X = 1,917,295'

Y = 10,093,235'

Lat. = 27.8113111

 27 48' 40.720"

Long. = -92.1431972

 -92 08' 35.510"

3,520' FSL & 1,797' FWL of GB 169

X = 1,918,437'

Y = 10,093,600'

Lat. = 27.8122934

 27 48' 44.256"

Long. = -92.1396557

 -92 08' 22.761"

1,650' FSL & 3,500' FWL of GB 169

X = 1,920,140'

Y = 10,091,730'

Lat. = 27.8071153

 27 48' 25.615"

Long. = -92.1344270

 -92 08' 03.937"

5/28/13
Y = 10,090,080'

Y = 10,074,240'

Y = 10,058,400'

X = 1,916,640'

X = 1,932,480'

213 214

168

256

212

169 170

257 258

APA

Loc.

“A”

APA

Loc.

“B”

APA

Loc.

“C”

SL

SL

SL

STRUCTURE MAP

Bathymetry Map 1" = 4000'

APACHE DEEPWATER, LLC

Garden Banks 213

OCS-G 31613 

C.I. = 20'

-900'

-1000'

-1100'

-800'

5/28/13
Apache Deepwater LLC	 	 Page B‐1

Revised Initial Exploration Plan	 	 June 18, 2013

Garden Banks Block 213 (OCS‐G 31613)	 	

 SECTION B 

GENERAL INFORMATION 

(30 CFR 550.213 and 550.243) 

A. APPLICATIONS AND PERMITS

The table below lists the additional permits/applications to be filed before operations can 

commence under this EP: 

Application/Permit Issuing Agency Status 

Application for Permit to Drill (APD) BSEE To be submitted 

 

B. DRILLING FLUIDS 

Type of Drilling Fluid Estimated Volume of Drilling Fluid to be 

Used per Well 

Water-based (seawater, freshwater, barite) 30,000 bbl / well total 

Oil-based (diesel, minerals, oil) 0 bbl / well total 

Synthetic-based (internal olefin, ester) 13,948 bbls / well total 

Product Name Amount to be Used 

M-I Bar 5,800,200 lbs / well total 

Synthetic B 582,112 gal / well total 

Suremul 12,192 gal / well total 

Surewet 6,336 gal / well total 

Rheflat 1,848 gal / well total 

Rhethik 891 gal / well total 

Lime 61,680 lbs / well total 

Calcium Chloride 201,840 lbs / well total 

C. NEW OR UNUSUAL TECHNOLOGY 

Apache Deepwater does not propose to use any new or unusual technology to carry out the 

proposed exploration activities. 

D. BONDING STATEMENT 

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

$3,000,000.00 area wide development bond, furnished and maintained according to 30 CFR 256 

subpart I; NTL No. 2000-G16 - “Guidelines for General Lease Surety Bonds”; and additional 

security under 30 CFR 256.53(d) and National NTL No. 2008-N07 - “Supplemental Bond 

Procedures”. 

E. OIL SPILL FINANCE RESPONSIBILITY (OSFR) 

Apache Deepwater LLC, (company number 03165) has demonstrated oil spill financial 

responsibility for this EP according to 30 CFR Part 253 and NTL No. 2008-N05 - “Guidelines 

for Oil Spill Financial Responsibility for Covered Facilities”. 
Apache Deepwater LLC	 	 Page B‐2

Revised Initial Exploration Plan	 	 June 18, 2013

Garden Banks Block 213 (OCS‐G 31613)	 	

F. DEEPWATER WELL CONTROL STATEMENT 

Apache Deepwater LLC, (company number 03165) has the financial capability to drill a relief 

well and conduct other emergency well control operations. 

G. BLOWOUT SCENARIO 

Estimated maximum flow rate 

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 Discharge (WCD) modeled for this scenario is 

395,611 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, drilling a relief well to kill the 

blowout. The expected maximum time frames for uncontrolled flow in each of the different 

operational outcomes would be as follows: 

 Bridging Over in 2 Days, 

 Surface Intervention in 15 Days, 

 A Relief Well in 96 Days. 

Maximum discharge volume 

The following table is a linear estimate of the 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 395,611 2 791,222 

Surface 

Intervention 

395,611 15 5,934,165

Relief Well 395,611 96 37,978,656 

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 open 

hole section. A Merlin reservoir simulation model was used to investigate the well conditions 

during the WCD blowout scenario. The estimated reservoir pressure is 17,437 psi. The reservoir 

model estimates bottom hole flowing pressures, based upon reservoir properties and flow rates. 

The calculated drawdown is modeled to be 4,619 psi. 
Apache Deepwater LLC	 	 Page B‐3

Revised Initial Exploration Plan	 	 June 18, 2013

Garden Banks Block 213 (OCS‐G 31613)	 	

In our experience in the deepwater GOM, we strive to limit the estimated total drawdown on a 

producing interval to reduce the risk of wellbore collapse and sand/fines migration into a well. 

We limit the drawdown to less than 1,000 psi by reducing the rates that 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 4.6 times or greater than our operating practices, 

 The blowout occurs in a long 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 the conditions cited are estimated not to 

exceed 2 days. 

Surface intervention to stop the blowout 

In the event of a blowout and assuming 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) containment system to achieve successful containment of 

the well. The system will be employed, while simultaneously initiating relief well planning and 

operations. Specifics will be submitted within the Well Containment Plan. 

Typically blowouts can be controlled with surface intervention, with a good likelihood of success 

and in a relatively short time frame, as long as, the subsea casing, wellhead 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 more complex solutions, but the solution will depend on wellbore conditions. 

Surface intervention time estimate 

The assumption is that the well has an uncontrolled blowout and the MODU has sunk with 

displacement from the wellhead. Additionally, it assumes 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 the 

aforementioned containment system’s capping BOP. 

The table on the next page describes the estimated time required to shut in and secure the well 

using the containment system or capping stack. Note that these operations all basically start at 

the same point in time and are performed in parallel. The entire operation is estimated to take 15 

days from start of site assessment until the capping stack has been deployed and the well shut in. 
Apache Deepwater LLC	 	 Page B‐4

Revised Initial Exploration Plan	 	 June 18, 2013

Garden Banks Block 213 (OCS‐G 31613)	 	

Duration of a well capping operation 

Operation Incremental 

Duration 

(days) 

Cumulative Time Since 

Event Start 

(days) 

Assess wellbore conditions for surface 

intervention requirements. Conduct 

notifications to the regulatory agencies 

and primary contractors. 

2 2 

Site Preparation which includes 

mobilizing and deployment of the 

IWOCS system and Dispersant 

system. 

5 5 

Debris removal including mobilization 

of ROV boat and construction support 

vessel and execution of debris removal 

plan. 

7 7 

Well capping and/or cap and flow 

operations which include mobilization, 

deployment, and installation of the 

well containment system. 

15 15 

Relief Well 

It is preferred to drill relief wells from an open water location, rather than 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 any platforms in the vicinity; therefore, it is not 

feasible to consider a platform as a relief well location. 

Relief well location and drilling strategy 

Proprietary Information 
Apache Deepwater LLC	 	 Page B‐5

Revised Initial Exploration Plan	 	 June 18, 2013

Garden Banks Block 213 (OCS‐G 31613)	 	

Relief well rig availability 

The rigs listed below could be available for relief well operations: 

Rig Name Contractor 

Rated 

Water 

Depth 

MODU Type Rig Status 

Ocean Victory Diamond 5,500 Moored Semi Contracted GOM 

Amos Runner Noble 8,000 Moored Semi Contracted GOM 

Jim Thompson Noble 6,000 Moored Semi Contracted GOM 

Driller Noble 5,000 Moored Semi Contracted GOM 

Deepwater Nautilus Transocean 8,000 Moored Semi Contracted GOM 

Relief well package constraints 

The proposed rigs for relief well operations have suitable drilling packages with sufficient 

capabilities to work in the subject water depths and drill to the required relief well depth. The 

BOP systems have met the BSEE certification 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 

A suitable rig could be selected and a contract finalized in 48 hours after undertaking the 

decision to begin relief well operations. Backup tubular goods and wellhead systems are 

maintained in stock for each well. Mobilization of equipment and services to the rig for the 

relief well could be completed while operations required to suspend the rig’s current activity 

were taking place. The time required to contract, mobilize, drill a relief well and kill the blowout 

well is estimated at 96 days and is summarized below. The relief well with surface location of 

GB 213 Location B was used for this example. 
Apache Deepwater LLC	 	 Page B‐6

Revised Initial Exploration Plan	 	 June 18, 2013

Garden Banks Block 213 (OCS‐G 31613)	 	

Duration of relief well 

Description Days Cumulative Days 

Well Control Assessment. Identify suitable 

MODU for relief well operations 2 2 

MODU suspends operations from current well. 

Contract to be executed and Well Spud 

Equipment is mobilized 

14 16 

Mobilize Rig and install 36” Structural Casing 10 26 

Spud and drill to the top of the zone of interest 

and set casing. 60 86 

Mag-Range relief well into intersecting position. 5 91 

R/U pumping equipment and kill well. 5 96 

R/D Pumping Equipment, PA Wellbore, Pull 

Riser, and Demobilize 15 111 

Blowout Prevention and Intervention 

Summary of prevention measures 

Apache Deepwater LLC 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 required BSEE testing 

requirements, 

 Current Well Control Certification for all Drilling and Completion Rig Site 

Supervisors, 

 Taking Slow Pump Rate measurements during all open hole 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 displacements 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. 
Apache Deepwater LLC	 	 Page B‐7

Revised Initial Exploration Plan	 	 June 18, 2013

Garden Banks Block 213 (OCS‐G 31613)	 	

The utilization of Pre-Job Safety meetings will continue to be implemented prior to each 

operation with all of the rig crews. 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 contractor’s crew, empowering every crew member to 

question the safety of each operation. 

Early well control intervention 

In the event of a blowout situation, due to failed BOP equipment and uncontrolled flow at the 

seafloor or at surface, assuming all other surface controlled actuation measures have failed or are 

inaccessible, a ROV will fly into position at the BOP subsea actuation panel and actuate the 

shear ram or pipe rams to establish containment. 

If the riser system and rig have been compromised, 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, well kill operations can be initiated through 

the existing wellbore. 

Well control engineering services 

Apache will have service agreements in place with Wild Well Control and Boots and Coots 

International Well Control prior to commencement of well operations. In the event of a blowout 

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 isolation techniques, all cementing operations will be 

modeled and designed under the guidelines set forth in API Recommended Practice 65 Part 1 & 

2. Operations will be dictated by the rules and requirements set forth in Federal Regulations, 

under the wellbore cementing requirements. 

API Standard 53 for Blowout Prevention Equipment Systems for Drilling Wells and 

Recommended Practice 16Q for Marine Drilling Risers will be used as the guidelines for 

installation, testing and maintenance of the surface and subsea Marine 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 prevention 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, and integrity of the drilling equipment and preservation of the 

environment for floating marine drilling operations. These recommended practices help to 

facilitate the broad availability of proven, sound engineering and operating practices. 

These practices are considered acceptable for accomplishing BOP and Marine Riser associated 

operations. However, equivalent alternative installations and practices may be utilized to 

accomplish the same objectives. When using these recommended practices or other alternatives, 

Apache will insure that operations comply with requirements of Federal Regulations. 
Apache Deepwater LLC	 	 Page C‐1

Revised Initial Exploration Plan	 	 August 20, 2013

Garden Banks Block 213 (OCS‐G 31613)	 	

SECTION C 

GEOLOGICAL AND GEOPHYSICAL INFORMATION 

(30 CFR 550.214 and 550.244) 

A. GEOLOGICAL DESCRIPTION 

Proprietary Information 

B. STRUCTURE CONTOUR MAPS 

Proprietary Information 

C. INTERPRETED 3-D SEISMIC LINE 

Proprietary Information 

D. GEOLOGICAL STRUCTURE CROSS SECTIONS 

Proprietary Information 

E. SHALLOW HAZARDS 

A Shallow Hazard Survey was conducted over Garden Banks Block 213 by Geoscience Earth & 

Marine Services, Inc. (GEMS). One (1) copy of the Shallow Hazard Report is being submitted 

to the BOEM in conjunction with this plan. 

F. SITE-SPECIFIC SHALLOW HAZARDS ASSESSMENT 

A Shallow Hazards Assessment was prepared for the proposed surface locations utilizing the 3-D 

seismic exploration data 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 Information 
10615 Shadow Wood Drive, Suite 200 

 Houston, Texas 77043

 713.468.1410[o] 713.468.1438 [f] 

www.gemsinc.com 

May 14, 2013 Project No. 0712-2118b 

Apache Deepwater LLC 

2000 W. Sam Houston Parkway South 

Suite 1600 

Houston, TX 77042 

Attention: Mr. John Worthen 

Site Clearance Letter 

Proposed Wellsite GB213-A 

Block 213 (OCS G-31613) 

Garden Banks Area 

Gulf of Mexico 

Apache Deepwater LLC (Apache) contracted Geoscience Earth & Marine Services, Inc.®, (GEMS) to 

prepare a Site Clearance Letter for the proposed bottom hole location in Block 213 (OCS G-31613), 

Garden Banks (GB) Area. The surface location for GB213-A is in Garden Banks Block 169. This letter 

addresses specific seafloor and subsurface geologic conditions around the proposed location to the limit 

of investigation, 4,282 ft below the mudline (bml). Apache will drill the proposed GB213-A with an 

anchored semi-submersible drilling rig. The seabed conditions within a 5,946 ft mooring radius plus an 

additional 1,000 ft buffer zone are discussed to satisfy seabed disturbance guidelines. 

Surface conditions are clear at the proposed wellsite; however, moorings or other seabed disturbance 

activities need to avoid unidentified sonar contacts and potential sites for benthic communities. 

Overconsolidated soils will exist beneath a thin drape of soft clays. A sandy interval with some potential 

for shallow gas occurs at 594 ft bml to 1,475 ft bml. 

This letter provides the following details specific to the well location: available data, attachments 

(accompanying the letter), Notice to Lessees (NTL) requirements, man-made features and archaeological 

assessment, wellsite conditions, anchoring considerations, and the conclusions and recommendations. 

Proposed Well Location and Available Data 

The proposed GB213-A surface location lies in the southwestern corner of GB 169 (Figure GB213-A-1). 

Apache provided the following coordinates: 

Proposed Wellsite GB213-A (Surface Location GB 169) 

Spheroid & Datum: Clarke 1866, NAD27 

Projection: UTM Zone 15 North Line Reference Block Calls 

GB 169 

X: 1,917,295 ft Latitude: 27o 48’ 40.72” N Inline 4899 655 ft FWL 

Y: 10,093,235 ft Longitude: 92o 08’ 35.51” W Crossline 5212 3,155 ft FSL 

The details provided in this letter are based on the findings from a geohazard assessment performed by 

GEMS (GEMS, 2013a). The report, which was submitted to Apache in January 2013 described the 

geologic and archaeological conditions within the Bimini Prospect (GB 168 and GB 213 and surrounding 

area). Apache provided two sets of geophysical data for this assessment: a conventional, 

3-D exploration seismic volume and high-resolution Autonomous Underwater Vehicle (AUV) data. 

The detailed data specifications are provided in the main report (GEMS, 2013a). Integrating these data 

allowed a thorough analysis of potential drilling hazards within the suprasalt stratigraphy at the proposed 

wellsite. In addition, a seafloor survey was conducted in February, 2013 using a Remotely Operated 
Proposed Wellsite GB 213-A Clearance Letter 

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FORUM ENERGY TECHNOLOGIES, INC. 

Vehicle (ROV). The survey documented seabed sediment distribution, assessed types and diversity of 

benthic communities, and investigated several unidentified sonar contacts delineated in the geohazard 

survey (GEMS, 2013b). 

Attachments 

The maps and accompanying illustrations were extracted from the available data provided by Apache. A 

moored semi-submersible drilling platform is planned for this location; therefore, a maximum anchor 

radius of 5,946 ft and an additional 1,000 ft buffer zone are included on the maps. The figures embedded 

within the body text are also provided below. 

Map No. GB213-A-1: Bathymetry Map 

 Map No. GB213-A-2: Seafloor Features Map 

Map No. GB213-A-3: Side-Scan Sonar Mosaic 

Map No. GB213-A-4: Geologic Features Map 

Illustration GB213-A-1: Portions of Inline 4899 and Crossline 5212 Showing Conditions Beneath 

Proposed Wellsite GB213-A 

Illustration GB213-A-2: Tophole Prognosis Chart, Proposed Wellsite GB213-A, Garden Banks, 

Block 213 

Figure GB213-A-1: Regional Rendering of the Garden Banks Area, Gulf of Mexico 

Figure GB213-A-2: Power Spectrum Analysis Curve, Proposed Wellsite GB213-A 

Figure GB213-A-3: Seafloor Conditions at the Proposed Wellsite 

Figure GB213-A-1. Regional Rendering of the Garden Banks Area, Gulf of Mexico 

 
Proposed Wellsite GB 213-A Clearance Letter 

Apache Deepwater LLC // May 14, 2013

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FORUM ENERGY TECHNOLOGIES, INC. 

NTL Requirements

The following letter complies with the Bureau of Ocean Energy Management (BOEM) Notice to Lessees 

(NTL’s) 2008-G04, 2008-G05, 2009-G39, and 2009-G40, (MMS, 2008a,b and 2010a,b). The 

requirements set forth in NTL 2005-G07 are applicable because the Federal lease block GB 213 is 

considered to be a high probability archaeological block (MMS, 2005 and BOEM, 2011). In compliance 

with NTL 2005-G07, the required archaeological assessment was performed by GEMS and included as 

an appendix in the main report (GEMS, 2013a). 

Garden Banks Blocks 168, 169, and 213 are located in Military Warning Area W-147 AB. Drilling 

operations, therefore, must be coordinated with the appropriate military command as per NTL 2009-G06 

(MMS, 2009). 

According to NTL 2008-G05 (MMS, 2008b), 3-D seismic reflection data may be used for shallow hazard 

assessments with approval from the BOEM, Gulf of Mexico Region. A power spectrum analysis was 

conducted from the 3-D seismic data cube provided by Apache to illustrate the data parameters 

(Figure GB213-A-2). The power spectrum curve was generated within a 500 ft radius of the intersection 

of the inline and crossline at the proposed wellsite. 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. 

Figure GB213-A-2. Power Spectrum Analysis Curve, Proposed Wellsite GB213-A 

Man-Made Features and Archaeological Assessment

The surface location is clear of any wells, pipelines, or platforms within a 2,000 ft radius from the 

proposed wellsite. The closest existing well (McMoran GB 168-001) is located approximately 3 miles 

west-northwest of the proposed wellsite location in GB 169 (Map GB 213-A-1). The well was an 

exploratory well and has been plugged and abandoned. No pipelines or umbilicals occur within 3 miles of 

the proposed location. 

GEMS delineated nine unidentified side-scan sonar contacts within 6,946 ft (5,946 ft maximum anchor 

radius plus 1,000 ft buffer) of the proposed GB213-A wellsite (Maps GB213-A-2 and 213-A-3). None of 

the nine contacts appear to represent cultural resources and no target has been recommended for 

archaeological avoidance or investigation. In addition, these contacts were investigated during an ROV 
Proposed Wellsite GB 213-A Clearance Letter 

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FORUM ENERGY TECHNOLOGIES, INC. 

survey in February 2013 (GEMS, 2013b). Contacts Nos. 32 through 43 were man-made debris which 

included piles of modern cable or rope, a steel beam, and a 55-gallon drum. These objects do not appear 

to be of archaeological significance. No archaeological or hazard avoidance is recommended for these 

objects. Contacts Nos. 45 through 51 were small patches of carbonate rubble and rock with anemones 

and a few other benthic organisms. Only Contact No. 51 showed any appreciable relief. A 100 ft 

avoidance is required by NTL 2009-G39 for the outcrop represented by Contact No. 51. 

Sonar Contacts Located Within 6,946 ft of GB213-A 

No. Area Block Length 

(ft) 

Width 

(ft) 

Height 

(ft) Shape 

X 

NAD27 

(ft) 

Y 

NAD27 

(ft) 

ROV Identification 

of Contact 

Avoidance 

Radius (ft) 

32* GB 168 27.21 5.12 0.00 Linear 1915172.17 10096921.19 Pile of cable 0 

38* GB 168 42.69 2.07 0.00 Linear 1915827.66 10094509.00 Steel beam 0 

39* GB 169 16.46 3.21 0.00 Irregular 1921872.49 10094142.83 Pile of cable 0 

42* GB 169 12.55 3.01 0.00 Linear 1920493.75 10093433.92 55-gallon drum 0 

43* GB 168 12.06 2.51 0.00 Linear 1912268.41 10092780.58 Rock outcrop 0 

45* GB 168 33.11 5.12 0.00 Linear 1912569.00 10091898.82 Rock outcrop 0 

46* GB 168 18.58 9.03 0.00 Irregular 1912591.60 10091862.18 Rock outcrop 0 

47* GB 168 14.76 6.04 0.00 Irregular 1912890.96 10092189.33 Rock outcrop 0 

51* GB 212 18.56 8.03 20.36 Irregular 1915932.82 10087450.33 Rock outcrop 100 

*Sites investigated during ROV survey in Feb. 2013 (GEMS, 2013b). 

Wellsite Conditions

The proposed surface location is clear of any constraining seafloor geologic conditions as defined by the 

available geophysical data. GB 213-A is not expected to intersect faults (seabed or buried) and the 

potential for encountering significant amounts of shallow gas is generally low. 

Water Depth and Seafloor Conditions

The water depth at the proposed surface location is approximately -919 ft and the seafloor slopes northnorthwest at 2.7° (Map GB213-A-1). The seabed is relatively featureless within 2,000 ft of the proposed 

wellsite (Map GB213-A-2). 

Side-scan sonar data show that the seabed in the vicinity of the proposed wellsite is characterized by 

uniform, low-reflectivity sediments (Map GB213-A-3). The low reflectivity is caused by a drape of soft clays. 

Subbottom profiler data indicate a 10 ft thick acoustically transparent layer at the seabed (Figure GB213-A3). The drape overlies intervals of parallel bedded and acoustically amorphous sediments. The drape thins 

to the south and southeast along the flank of Muskogee Mound. 
Proposed Wellsite GB 213-A Clearance Letter 

Apache Deepwater LLC // May 14, 2013

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FORUM ENERGY TECHNOLOGIES, INC. 

Figure GB213-A-3. Seafloor Conditions at the Proposed Wellsite 

Biologically Sensitive Features and Deepwater Benthic Communities 

The water depth at GB213-A is less than 300 m (984 ft); therefore, guidelines set forth in NTL 2009-G39 

(MMS, 2010a) are in effect. There are no apparent geophysical indicators at the seafloor or at depth that 

would suggest conditions capable of supporting biologically sensitive benthic communities in the 

immediate vicinity of the proposed location (Maps GB213-A-2 and GB213-A-3). 

The 300-m contour, defining deepwater areas, occurs about 1,200 ft to the north of the GB213-A 

proposed location. The deepwater portion of the 2,000 ft radius shows no features or conditions 

indicative of hydrocarbon seepage or hardgrounds; therefore, there is a negligible potential for deepwater 

benthic communities within 2,000 ft of the proposed location. 

Stratigraphy 

Stratigraphic conditions are shown on Illustrations GB213-A-1 and GB213-A-2. The sediments below the 

seafloor to the limit of investigation (4,282 ft bml or -5,201 ft bsl) consist primarily of hemipelagic clays, 

muddy- to sand-prone turbidites, and mass-transport deposits. 

The shallow stratigraphy (Seafloor to Horizon 10) is interpreted to be hemipelagic, clay-rich sediments 

down to approximately 96 ft bml. The surficial 10 ft thick drape will consist of soft, normally consolidated 

sediments. Beds beneath the drape thin and pinch-out to the south along the flank of Muskogee Mound. 

Bed truncations indicate unconformities in the shallow section. Soils will likely increase in shear strength 

and become overconsolidated above Horizon 10. Stiffer than normal sediments should be expected 

when installing the surface conductor. 

The sequence from Horizon 10 to Horizon 40 consists of bedded hemipelagic sediments and mud-rich 

turbidites (Illustrations GB213-A-1 and GB213-A-2). Horizons 20 and 30 appear to onlap Horizon 40 to 

the north of the proposed location. The interval from Horizon 10 to Horizon 40 is about 498 ft thick. 

Beneath Horizon 40 (594 ft bml) the sequence shows discontinuous to bedded reflectors of low to 

moderate amplitudes. The interval likely represents turbidites that have been disrupted by faulting 

caused by uplift of the diapir beneath Muskogee Mound. Scattered small amplitude events within this 

interval suggest sand-rich layers and seams. The turbidite interval extends from 594 ft to 1,475 ft bml. 
Proposed Wellsite GB 213-A Clearance Letter 

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The section from 1,475 ft to 3,506 ft bml consists of layers of chaotic mass-transport sediments. The lowamplitude character of these intervals suggests mud-rich sediments. 

The section from 3,506 ft to the limit of the investigation (4,282 ft bml) consists of steeply dipping beds 

along the flank of the salt diapir. Turbidites consisting of alternating layers of clay, silt, and sand comprise 

this interval. 

Faults 

A vertical wellbore at the proposed location will not penetrate seafloor or buried faults between the 

seafloor and the limit of investigation (Illustrations GB213-A-1 and GB213-A-2). However, the top of a 

buried fault occurs a few hundred feet southeast of the proposed wellsite GB213-A. The fault is 

downthrown southeast away the wellbore and is buried by at least 550 ft of sediment. 

Shallow Gas and Shallow Water Flow 

Shallow Gas. No high-amplitude events will be intersected by the wellbore beneath GB213-A; however, 

a few small events occur along the fault plane to the southeast of the location. The moderate amplitude 

of the interval beneath Horizon 40 (594 ft to 1475 ft bml) has some potential for shallow gas. Pressures 

significantly greater than hydrostatic are not anticipated but drillers may notice an increase in the amount 

of solution gas when penetrating this interval. 

Shallow Water Flow. There is a negligible to low potential for overpressured sands in this area. The 

deformation of the section by faulting, folding, and erosion has likely allowed any overpressured sands to 

dewater through time. In addition, most of the sequences appear to be mud-rich units. 

Anchoring Considerations

The 5,946 ft radius outlined on the accompanying maps represents the area of potential effect for 

anchoring. An additional 1,000 ft buffer zone is also included although, technically, this buffer is only 

required in deepwater areas (i.e. >300 m or 984 ft) as specified in NTL 2009-G40. The following 

discussions address the seafloor conditions related to anchoring considerations within the total 6,946 ft 

radius. 

Water Depth and Seafloor Conditions

Water depths within the potential mooring area range from about -610 ft to -1,260 ft (Map GB213-A-1). 

The seafloor generally slopes to the north away from an east-west trending topographic high that crosses 

the southern one-third of the mooring radius. The shallowest water depths within the anchor radius are 

associated with this high. The elongated topographic high approximates the crest of Muskogee Mound. 

The seafloor slopes to the south into deeper water on the southern margin of the high. 

Seafloor gradients within the northern two-thirds of the mooring radius range from 2° to 4°. The seabed in 

this area consists of soft, clay-rich sediments. The normally consolidated clay sediments thicken to the 

north away from the topographic high in the southeast. The normally consolidated silty clays will range 

from 10 ft at the proposed wellsite to over 200 ft along the northern boundary. The normally consolidated 

drape will pinch-out a few hundred feet south of the proposed wellsite. Relatively stiff, overconsolidated 

sediments will occur throughout most of the southern half of the mooring pattern. 

The irregular seabed in the southern one-third of the mooring pattern occurs along the flanks of the 

topographic high. Slopes ranging from 6° to 12° are common (GEMS, 2013a). Local gradients of 25° are 

associated with some high-relief carbonate outcrops. Areas of nearly flat seafloor occur along the crest of 

the topographic high in the southeast quadrant of the mooring pattern. 

The irregular seafloor morphology is associated with carbonate hardgrounds probably representing relict 

reef formations. The hardgrounds include large boulders, pinnacles, and slabs (Map GB213-A-2). The 

area around the hardgrounds and across the relatively flat-topped crest of Muskogee Mound consists of 

muds with varying amounts of sand to cobble-sized carbonate rubble. The high-relief outcrops exhibit a 

rough and rocky character on side-scan sonar records (Map GB213-A-3). The flat-lying areas consisting 
Proposed Wellsite GB 213-A Clearance Letter 

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of muds with varying amounts of sand to cobble-sized carbonate rubble show a uniformly high reflectivity 

seabed but lack the “rocky” texture. 

Portions of Muskogee Mound are affected by seafloor faults. Low-relief, northwest-southeast trending 

fault escarpments occur along the southwestern edge of the anchor radius (Map GB213-A-2). East-west 

trending escarpments occur within the southern and southeastern portion of the mooring pattern. The 

faults will not be a constraint to anchoring. 

A few scattered seafloor depressions or “pockmarks” occur in the western half and near the northern 

border of the mooring pattern (Map GB213-A-2). The pockmarks are not associated with gas-charged 

sediments at the seafloor. In addition, there are no indications on the seabed of hydrocarbon seepage or 

the presence of hardgrounds within the pockmarks (Map GB213-A-3). 

Biologically Sensitive Communities and Deepwater Benthic Communities 

Most of the mooring pattern will occur in water depths less than 300 m (984 ft); therefore, NTL 2009-G39 

guidelines regarding biologically sensitive communities will apply to rig and anchor placement (MMS, 

2010a). Lithified hardgrounds of moderate to high relief (i.e., 8 ft or greater) occur along the flanks of 

Muskogee Mound in the southern half of the mooring pattern (Map GB213-A-2). The hardgrounds 

support sessile invertebrates and attract large numbers of fish. The hardgrounds will need to be avoided 

by 30 m (~100 ft) by rig placement, construction barges, and supporting anchors, chains, cables and wire 

ropes. 

The mooring pattern north and west of the proposed wellsite will extend into water depths greater than 

300 m (Map GB213-A-2). No features occur within the deepwater portion of the mooring pattern that are 

likely to be sites of deepwater benthic communities. A few subtle depressions occur to the north and 

west of the proposed wellsite; however, the AUV data over these depressions show no indications of gascharged sediments or hardground formation at the seabed (Map GB213-A-3). 

Conclusions and Recommendations

We appreciate the opportunity to be of service to Apache and look forward to working with Apache on 

future projects. The conclusions and recommendations from this assessment are as follows: 

Wellsite Conditions 

No major seafloor hazards or constraints are defined by the available data within a 2,000 ft radius of the 

proposed location. Shallow soils are likely to be stiffer and more consolidated than typical slope soil 

profiles. Caution is recommended when drilling through the turbidite interval between 594 ft and 1,475 ft 

because of the presence of amplitude events along a nearby fault plane. 

Anchor Maximum Radius Conditions 

The potential seafloor constraints within the mooring radius include possible hard grounds that could 

support biologically sensitive communities. A minimum avoidance of 30 m (~100 ft) is recommended 

around the moderate to high relief hardgrounds. In addition, a 100 ft shallow hazard avoidance is 

recommended for side-scan sonar contact No 51 which is a rock outcrop >8 ft high within the mooring 

pattern. If any potentially historic materials such as textiles, wood, ceramics, or other items be uncovered 

during operations in the area all operations must cease and BOEM notified within 48 hours. 

The proposed wellsite and its mooring pattern occur within the Military Warning area W-147-AB. Drilling 

operations will need to be coordinated with the appropriate military command prior to commencement. 

 
Proposed Wellsite GB 213-A Clearance Letter 

Apache Deepwater LLC // May 14, 2013

Geoscience Earth & Marine Services, Inc. ® // 8 

FORUM ENERGY TECHNOLOGIES, INC. 

 Sincerely, 

 GEOSCIENCE EARTH & MARINE 

 SERVICES, INC.®

Thomas Neurauter Ph.D. Daniel Lanier 

Senior Marine Geologist Vice President-Geosciences 

Attachments (4 Maps and 2 Illustrations) 

Distribution: 

Mr. John Worthen, Apache Deepwater LLC (3 copies) 

REFERENCES 

Bureau of Ocean Energy Management, 2013a, ASCII Data Files, published on the BOEM Gulf of Mexico Region 

Homepage, <http://www.gomr.boem.gov/homepg/pubinfo/freeasci/freedesc.html>, accessed January, 2013. 

Bureau of Ocean Energy Management, 2013b, Seismic Water Bottom Anomalies Map Gallery, published on the 

BOEM Homepage, <http://www.boem.gov/Oil-and-Gas-Energy-Program/Mapping-and-Data/Map-Gallery/SeismicWater-Bottom-Anomalies-Map-Gallery.aspx>, accessed April, 2013. 

Bureau of Ocean Energy Management, 2011, 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), Revisions to the list of OCS lease 

blocks requiring archaeological resource surveys and reports: U. S. Department of the Interior, Bureau of Ocean 

Energy Management, Bureau of Safety and Environmental Enforcement Gulf of Mexico Region (GOMR), NTL 2011-

JOINT-G01. Effective Date December 29, 2011. 

Coffeen, J. A., 1978, Seismic Exploration Fundamentals: Tulsa, the Petroleum Publishing Co., p. 125. 

Geoscience Earth & Marine Services, Inc.® (GEMS), 2013a, Geohazard assessment, Bimini Prospect, Blocks 168 

and 213, (OCS-G-34516 and OCS-G-31613) Garden Bank Area, Gulf of Mexico, Project No. 0712-2118b. 

Geoscience Earth & Marine Services, Inc.®

 (GEMS), 2013b, Seafloor verification study using ROV data, Bimini 

Prospect, Blocks 168 and 213, (OCS-G-34516 and OCS-G-31613) Garden Bank Area, Gulf of Mexico, Project No. 

0712-2118b. 

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 Management Service, 2008a, 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, 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. 

Minerals Management Service, 2008b, 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, 2009, 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, Military Warning and Water 

Test Areas: U. S. Department of the Interior, Minerals Management Service, Gulf of Mexico, NTL 2009-G06. 

Minerals Management Service, 2010a, Notice to lessees and operators of federal oil and gas leases in the outer 

continental shelf, Gulf of Mexico OCS region, Biologically-Sensitive Underwater Features and Areas: U. S. 
Proposed Wellsite GB 213-A Clearance Letter 

Apache Deepwater LLC // May 14, 2013

Geoscience Earth & Marine Services, Inc. ® // 9 

FORUM ENERGY TECHNOLOGIES, INC. 

Department of the Interior, Minerals Management Service, Gulf of Mexico, NTL 2009-G40. Effective Date January 27, 

2010. 

Minerals Management Service, 2010b, 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 2009-G40. Effective Date January 27, 2010.