Noble Energy, Inc. Page B-1

Revised Exploration Plan 10/6/2011

Mississippi Canyon 948 & 949 (OCS-G 28030 & 32363)

Section B

General Information

A. Applications and Permits

No additional applications or permits are required to conduct the activities proposed herein.

B. Drilling Fluids

Type of Drilling Fluid Estimated Volume of Drilling

Fluid to be used per Well

Water-based 43,000 bbls

Synthetic-based 14,000 bbls

C. New or Unusual Technology

Noble 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 an area-wide

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

for General Lease Surety Bonds;" and National NTL No. 2003-N06, "Supplemental Bond Procedures".

E. Oil Spill Financial Responsibility (OSFR)

Noble Energy, Inc., BOEMRE company number 02237, has demonstrated oil spill financial

responsibility for the facilities proposed in this EP according to 30 CFR Part 253; and NTL No. 99-N01,

"Guidelines for Oil Spill Financial Responsibility for Covered Facilities".

F. Deepwater Well Control Statement

Noble Energy, Inc., BOEMRE company number 02237, has the financial capability to drill a relief well

and conduct other emergency well control operations.

G. Blowout Scenario

This information is addressed under separate cover in the NTL 2010-N06, worst case discharge package

submitted along with this revised exploration plan.
Noble Energy, Inc. Page C-1

Revised Exploration Plan 10/6/2011

Mississippi Canyon 948 & 949 (OCS-G 28030 & 32363)

Section C

Geological and Geophysical Information

A. Geological Description

Proprietary Data

B. Structure Contour Map

Proprietary Data

C. Interpreted 3-D Seismic Lines

Proprietary Data

D. Geological Structure Cross-Section Maps

Proprietary Data

E. Shallow Hazards Report

A shallow hazards survey was conducted over Mississippi Canyon 948. Locations F, G and H are within

50 feet of each other, therefore the site clearance letter is intended to cover all three locations.

F. Shallow Hazards Assessment

Utilizing the 3D seismic exploration data, a shallow hazards assessment was prepared for the proposed

surface locations, and is included as Attachment C-4. The shallow hazards assessments of the

proposed well locations are also included in the “Wellsite Discussion” section of the combined Shallow

Hazards Assessment, Benthic Communities Evaluation, and Archeological Resource Survey being

submitted with this EP. The initial plans for this project were to use a moored rig, therefore the

assessment mentions anchor considerations. The rig for this project has changed and will be a

dynamically positioned rig.

G. High-Resolution Seismic Lines

Proprietary Data

H. Stratigraphic Column

Proprietary Data

I. Time vs. Depth Table

Proprietary Data
10615 SHADOW WOOD DRIVE 

SUITE 200 

HOUSTON, TEXAS 77043 

 Phone: (713) 468-1410 

Fax: (713) 468-1438 

E-mail: gems@gemsinc.com

March 21, 2011 Project No. 0609-1659 

Noble Energy, Inc. 

100 Glenborough, Suite 100 

Houston, TX 77067 

Attention: Mr. Jonas E. Harrell 

Site Clearance Letter 

Proposed Wellsite F 

Block 948 (OCS G-28030) 

Mississippi Canyon Area 

Gulf of Mexico 

Geoscience Earth & Marine Services, Inc.®, (GEMS) was contracted by Noble Energy, Inc., (Noble) to 

prepare a Site Clearance Letter for the Proposed Wellsite F in Block 948 (OCS G-28030), Mississippi 

Canyon (MC) area. This letter addresses specific seafloor and subsurface conditions near the proposed

location to a depth of about 3,600 ft below the mudline (bml). Our assessment is based on findings 

provided within the main body of the geohazard report “Geologic and Stratigraphic Assessment, Block 948 

(OCS G-28030), Mississippi Canyon Area, Gulf of Mexico” (GEMS, 2007; Project No. 0407-1324). The 

text, maps, and figures included in the report provide detail to the regional geology of the Study Area. This 

letter supplements the report with details pertaining directly to the proposed wellsite. 

The following report complies with the Bureau of Ocean Energy Management, Regulation, and 

Enforcement (BOEMRE) Notice to Lessees (NTL’s) 2008-G04, 2008-G05, and 2009-G40, (MMS, 2008a,b

and 2010). Block 948, Mississippi Canyon Area, is located in grid 16 of the BOEMRE’s Grid Map for 

ROV Surveys (MMS, 2008c); therefore, activities at the proposed wellsite will not be required to follow 

NTL 2008-G06 with respect to pre- and post-spud ROV visual inspection surveys. 

The above-stated Federal lease block is located within a historically significant area (MMS, 2008d); 

therefore, requirements set forth in NTL 2005-G07 (MMS, 2005) are applicable. Fugro Geoservices, Inc., 

(2007) conducted an archaeological survey and compiled an assessment for Noble over the Study Area. 

Their results in regards to the proposed location are mentioned herein. 

The surface location for the proposed F wellsite lies in the southeastern quadrant of Block 948, 

Mississippi Canyon area, Gulf of Mexico. Noble provided the following coordinates for the proposed 

location: 

Proposed Wellsite F 

Spheroid & Datum: Clarke 1866, NAD27 

Projection: UTM Zone 16 North Line Reference Block Calls MC 948 

X: 1,076,544 ft Latitude: 28.024469612o N Inline 13143 576 ft FEL 

Y: 10,173,777 ft Longitude: -88.748218162o W Crossline 11880 4,497 ft FSL 
Project No. 0609-1659 

 2 Wellsite MC 948-F 

Attachments 

The page-size maps and figures accompanying this letter were extracted from the main report’s original

maps and 3-D data volume. The maps and figures (listed below) are centered on the proposed well 

location. 

Map F-1: Bathymetry Map 

Map F-2: Seafloor Rendering 

Map F-3: Seafloor Amplitude Rendering 

Map F-4: Geologic Features Map 

Figure F-1: Inline 13143 and Crossline 11880 Showing Conditions Beneath Proposed Wellsite F 

Figure F-2: Tophole Prognosis Chart, Proposed Wellsite F, Mississippi Canyon Block 948 

Figure F-3: Power Spectrum Chart Based on 3-D Data Volume Within 500-ft Radius of Proposed 

Wellsite F, Mississippi Canyon Block 948. 

Man-Made Features 

Two existing exploration wellsites occur in MC 948 (Maps F-1 through F-4). The MC 948-1 well was 

spudded on May 19, 2008, but was abandoned within a week because of shallow water flow problems. 

The wellsite was moved approximately 160 ft to the southwest and MC 948-2 was spudded on May 25, 

2008. The MC 948-1 is approximately 3,230 ft south-southwest of the proposed F location. MC 948-2 is

approximately 3,325 south-southwest of the proposed location.

The 2-inch, BP fiber-optic cable crosses the northwest corner of MC 948 (Map F-1). The cable runs 

northeast-southwest. The closest point to the proposed F location is approximately 13,675 ft. The 

Mariner 8-inch pipeline and 3-inch umbilical occur east of the location within MC 949 (Map F-1). The 

lines run approximately north-south through the block. The closest point to the proposed location is 

approximately 5,725 ft. 

An evaluation of high-resolution geophysical data collected within MC 948 and the surrounding blocks 

indicate that the area is clear of any unusual seafloor targets that could represent shipwreck remains or 

debris of archeological significance (Fugro Geoservices, Inc., 2007). 

Water Depth and Seafloor Conditions

The water depth at the proposed location is approximately -6,045 ft (Map F-1). The seafloor at the 

proposed site dips to the south at approximately 1.0° (1.7%). The proposed location occurs in a relatively 

flat area where the seafloor is smooth and featureless (Maps F-1 and F-2). The near-surface sediments

are expected to be normally consolidated, soft clays forming a drape over the area. 

Deepwater Benthic Communities

There is no evidence of hydrocarbon seepage within 2,000 ft of the proposed location. The potential for 

significant, densely-populated deepwater benthic communities within 2,000 ft of the proposed location is 

negligible. The Seafloor Amplitude Rendering (Map F-3) shows normal or ambient amplitudes along the 

seabed near the proposed wellsite. 

Stratigraphy

The stratigraphy at the proposed well location is illustrated on Figures F-1 and F-2. The Tophole 

Prognosis Chart (Figure F-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. In general, the sediments between the seafloor and the limit of investigation (about 3,624 ft bml) 

consist of hemipelagic clays and stratified turbidites, interbedded with mass-transport deposits. The

stratigraphic sequence above the Top of Salt is likely to consist predominantly of clays and silts. 

Potential sands may occur between 449 ft and 1,351 ft bml. Stratigraphic units within this section consist 

of turbidite and slope-fan deposits that have been modified by submarine slides and mass-wasting events. 
Project No. 0609-1659 

 3 Wellsite MC 948-F 

Most sand seams encountered within these units are likely to be discontinuous. An interval at the base of 

the section between 1,241 ft and 1,351 ft bml appears to be the fill at the base of a channel or failure zone. 

Coarse sands may be ponded within this erosional low. 

A unit of sand-prone slope-fan deposits may also exist below 2,083 ft bml. Flat-lying turbidites are 

interbedded with channelized intervals and mass-transport deposits. Immediately above the salt/sediment 

interface is a rubble-like zone consisting of chaotic, discontinuous to amorphous reflectors. The 

deformation of this zone is the result of salt movement. The sediments within the zone are probably 

turbidites and mass-transport deposits consisting of clays and silts, interspersed with thin, discontinuous 

sands. 

Faults

Two buried faults will be penetrated by the Proposed Wellsite F in the shallow section to the limit of

investigation (Figures F-1 and F-2). The faults will be encountered at approximately 1,241 ft and 2,083 ft 

bml. Neither fault extends to the seafloor; therefore, both have been inactive for thousands of years. The 

fault at 1,241 ft bml occurs at the top of the possibly sand-rich fill of an erosional feature. 

Shallow Water Flow

The potential for shallow water flow ranges from negligible to high within the stratigraphic sequences

between the seafloor and the limit of investigation (about 3,624 ft bml). A low to moderate potential for 

water flow is generally expected within the turbidite and slope-fan deposits between 449 ft and 1,351 ft 

bml. These turbidite and slope-fan deposits appear to be modified by mass-wasting events at the 

proposed location. Sands encountered in the upper part of this section (449 ft to 975 ft bml) are probably 

discontinuous and are not likely to produce sustained flow. Therefore, the potential for overpressured

sand is considered low. 

The sequence between Horizon 40 and Horizon 50 is the source for water flow in the MC 948-1 well to 

the south. Sand-layers may be thicker and more continuous in this sequence and therefore, a "moderate" 

potential is given the upper part of the unit. The base of the section between 1,241 ft to 1,351 ft is given a 

high potential for overpressured sand. This 110 ft interval appears to be the fill in an erosional cut and 

shows slightly elevated amplitude returns. Sand layers and pockets may have ponded in this location. 

In addition, a moderate potential for encountering overpressured sands occurs between 2,083 ft and 

3,624 ft bml. Potentially thick and continuous sand deposits may exist within these stratified slope-fan 

deposits. 

Shallow Gas 

The potential for encountering shallow gas at the Proposed Wellsite F is generally negligible to low. 

However, a moderate potential is assigned to the fill interval just above Horizon 50 at 1,241 ft bml 

(Figure F-1 and F-2). The top of this interval is a relatively flat-lying reflector that has some 

characteristics of a bottom simulating reflector (BSR). It is limited in areal extent and appears offset by 

small faults which are not characteristics of a BSR. The amplitude of this reflector is only slightly

elevated. If this is the base of hydrate stability then minor concentrations of free gas may occur beneath 

the interface within the possibly sand-rich fill. 

Elsewhere in the section, the well path will not penetrate any exceptionally high-amplitude events in the 

3,624 ft above the Top of Salt (Figure F-1). Several high-amplitude anomalies occur in the area of the 

proposed site below Horizon 60 to the Top of Salt (approximately 2,083 ft to 3,624 ft bml). In general, 

these amplitude anomalies appear as elevated sections within relatively stratified turbidite deposits. The 

nearest high-amplitude event is approximately 2,100 ft north-northwest of the proposed site at 

approximately 2,850 ft bml (Map F-4). The high-amplitude anomalies near the site suggest a potential 

increase in minor amounts of solution gas within sand-rich layers. 
Project No. 0609-1659 

 4 Wellsite MC 948-F 

Power Spectrum 

In accordance with NTL 2008-G04 and NTL 2008-G05 (MMS 2008a,b), we have extracted the power 

spectrum diagram (Figure F-3) from the 3-D seismic data cube. The extraction was generated within a 

500-ft radius of the intersection of the inlines and crosslines at the proposed wellsite. The amplitude vs. 

frequency spectrum, generated by the SMT software, was converted to power vs. frequency by squaring 

the amplitude values as described by J. A. Coffeen, 1978. 

Anchoring Considerations 

An anchored drilling vessel is likely to be employed for the proposed F location. Anchors may extend 

12,000 ft to 15,000 ft from the proposed site (Maps F-1 through F-4). The anchors will need to avoid the 

seafloor crater approximately 10,320 ft to the southwest. Elevated seabed amplitudes associated with this 

expulsion feature suggest active hydrocarbon seepage and therefore has the potential for chemosynthetic 

communities. Minor seabed amplitude events also occur along the relatively steep erosional escarpments 

to the northwest (Map F-3). 

A cable crosses the northwest corner of MC 948. The cable is within 13,675 ft of the location. In 

addition, a pipeline and umbilical crosses MC 949 to the east of the location. These lines are within

5,725 ft of the proposed location. A 500 ft avoidance zone has been placed around the cable, pipeline, 

and umbilical as well as around the two existing exploration wellsites (Maps F-1 through F-4). 

No targets of potentially cultural importance were identified in this area (Fugro Geoservices, 2007). 

Closing 

The Proposed Wellsite F in Mississippi Canyon, Block 948, generally appears suitable for exploration 

drilling operations. Engineers should be aware that the area has potential for overpressured sand layers. 

Anchors locations must avoid existing cables, pipelines, and areas of potential chemosynthetic 

communities. We appreciate the opportunity to be of service to Noble Energy, Inc., and look forward to 

working closely with you on other projects. 

Sincerely, 

GEOSCIENCE EARTH & MARINE 

SERVICES, INC. 

Thomas W. Neurauter, Ph.D. Daniel Lanier 

Senior Marine Geologist Vice President Geoscience 

Attachments (4 Maps and 3 Figures) 

Distribution: 

Mr. Jonas E. Harrell, Noble Energy, Inc., Houston, TX (5 copies) 
Project No. 0609-1659 

 5 Wellsite MC 948-F 

REFERENCES 

Bureau of Ocean Energy Management, Regulation, and Enforcement, 2011, Free ASCII Data Files, 

published on the BOEMRE Gulf of Mexico Region Homepage, 

http://www.gomr.boemre.gov/homepg/pubinfo/freeasci/freedesc.html, Accessed March, 2011. 

Coffeen, J. A., 1978, Seismic Exploration Fundamentals: PPC Books, a division of Petroleum Publishing 

Co., Tulsa, Ok. 277 p. 

Fugro Geoservices, Inc., 2007, Archaeological Assessment, Block 948, Mississippi Canyon Area, Gulf of 

Mexico: Fugro Report No. 2407-5001. 

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. Effective Date July 1, 2005. 

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, 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 program: U. S. Department of the Interior, Minerals Management Service, Gulf of 

Mexico, NTL 2008-G05. Effective Date May 1, 2008. 

Minerals Management Service, 2008c, 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, 

Remotely Operated Vehicle Surveys in Deepwater: U. S. Department of the Interior, Minerals 

Management Service, Gulf of Mexico, NTL 2008-G06. Effective Date May 26, 2008. 

Minerals Management Service, 2008d, 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 region, 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. Effective Date October 20, 

2008. 

Minerals Management Service, 2010, 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.