**10615 Shadow Wood Drive Suite 200**  **Houston, Texas 77043 (713) 468-1410 (o)**  **(713) 468-1438 (f)** www.gemsinc.com

**Geoscience Earth & Marine Services, Inc. ®** // 1 FORUM ENERGY TECHNOLOGIES, INC. **July 10, 2012 Project No. 0412-2080** 

**C hevron U.S.A. Inc.**  **1500 Louisiana Room 5717F**  **Houston, Texas 77002**
**Attention: Mr. Philip Von Dullen III** 

### Site Clearance Letter Proposed Wellsite KC 692-B Block 692 (OCS G

**-** 25801) Keathley Canyon Area, Gulf of Mexico

**Chevron U.S.A. Inc., (Chevron) plans to drill an exploration well in Block 692 of the Keathley Canyon (KC) Area, Gulf of Mexico. This letter addresses specific seafloor and subsurface geologic conditions to a depth**  **of approximately 5,760 ft below the mudline (bml), at the Proposed Exploration Wellsite KC 692-B. The**  **f ollowing discussion is based on findings provided within the main body of the geohazards report for Blocks**  **KC 692, 693, 735, 736, and 780 and within the archaeological ROV assessment (GEMS Report Nos. 0109-1600 and 0112-2040; GEMS, 2009 and 2012 respectively).** 
**The surface location of the proposed KC 692-B wellsite lies in the southeastern portion of KC 692. Chevron provided the following coordinates:** 



### Proposed Exploration Wellsite KC 692-B

Spheroid & Datum: Clarke 1866, NAD27 Projection: UTM Zone 15 North, U.S. ft Line Reference Block Calls

KC 692
**X: 1,849,304 Latitude: 26o 17' 29.15597" N Inline: 14445 3,976 ft FEL Y: 9,540,505 Longitude: 92o 21' 44.07129" W Crossline: 5839 4,825 ft FSL** 

**Chevron plans to drill this well using a dynamically positioned drilling vessel. Our assessment addresses the seafloor conditions within a 2,000 ft radius around the proposed wellsite location.** 



### Attachments
**The page-size 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 No. KC692-B-1. Bathymetry Map**

• **Map No. KC692-B-2. Seafloor Rendering**

• **Map No. KC692-B-3. Seafloor Amplitude Rendering**

• **Map No. KC692-B-4. Geologic Features Map**

• **Figure KC692-B-1. Portions of Inline 14445 and Crossline 5839 Showing Conditions Beneath Proposed Wellsite KC 692-B** 

• **Figure KC692-B-2. Tophole Prognosis Chart, Proposed Wellsite KC 692-B, Keathley Canyon Area, Block 692** **Project No. 0412-2080**

**Chevron U.S.A. Inc. //**  **July 10, 2012**

**Geoscience Earth & Marine Services, Inc. ®** // 2 FORUM ENERGY TECHNOLOGIES, INC. 

### NTL Requirements
**The following report complies with the Bureau of Ocean Energy Management (BOEM, formerly MMS) Notice to Lessees (NTL’s) 2008-G05 and 2009-G40 (MMS, 2008a and 2010). The operator will be required** **to follow NTL’s 2008-G04 and -G06 with respect to an ROV monitoring survey as well as pre- and post spud ROV visual inspection surveys (MMS, 2008b and 2008c).** 
**The Federal lease Block KC 692 is not considered archaeologically significant (BOEM, 2011); however, pursuant to the “Pre-Seabed Disturbance Survey Mitigation” released by the BOEMRE in March 2011**  **(BOEMRE, 2011), an archaeological assessment of the well location will be required before any bottom disturbing activities. GEMS submitted an archaeological ROV assessment for Keathley Canyon Block 692**  **to Chevron in March 2012 (GEMS, 2012). This archaeological ROV assessment satisfies the BOEMRE requirement.** 
Power Spectrum. **According to NTL 2008-G05 (MMS, 2008a), 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 Chevron 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. 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, KC 692, Proposed Wellsite KC 692-B



### Man-Made Features
**The KC 736 #1 well was drilled by Chevron in 2010 in the southern portion of KC 736, approximately 3.9 miles southwest of the proposed well location. The KC 736 #1 well is permanently abandoned. There**  **are no existing pipelines, cables, or platforms within KC 692 or in the immediate surrounding blocks (BOEM, 2012).** 

**0 0.1**  **0.2 0.3**  **0.4 0.5**  **0.6 0.7**  **0.8 0.9**  **1**

**0 10 20 30 40 50 60 70 80 90 100**Power (Amp2)

Frequency (Hz) POWER SPECTRUM**Project No. 0412-2080**

**Chevron U.S.A. Inc. //**  **July 10, 2012**

**Geoscience Earth & Marine Services, Inc. ®** // 3 FORUM ENERGY TECHNOLOGIES, INC. 

### Wellsite Conditions
**The surface location is clear of any constraining geologic conditions within a 2,000-ft radius from the proposed wellsite.** 
Water Depth, Slope, and Seafloor Sediments. **Seafloor conditions are generally favorable for exploration drilling at the proposed wellsite location. The water depth at the proposed surface location is approximately**  **-7,125 ft (Map KC692-B-1). The seafloor at the proposed wells**  **ite is generally smooth, and dips to the east northeast at a fairly steep inclination of 9.9°. The ROV data confirms a relatively smooth mud bottom**  **across the proposed well location. The near-surface sediments are expected to be normally consolidated clays forming a drape over the area. The Proposed Wellsite KC 692-B is situated along the flank of a**  **broad intraslope basin named Chalmette Basin. An expansive shallow salt ridge lies approximately 2,000 ft west-southwest of the proposed well location. The seafloor along the salt ridge is irregular as a result of**  **numerous fault scarps, seafloor failures, and the deformation of the shallow overburden by the underlying salt (Map KC692-B-2).** 
**A shallow slope failure scarp lies approximately 100 ft to the west of the proposed location. Relief along the failure scar ranges from about 15 ft to 30 ft. Slopes across the scarp vary from approximately 7° to 25°.**  **Throughout the northern Gulf of Mexico continental slope region, many slope failures are covered with a surficial drape of Holocene-aged pelagic sediments (Doyle et al., 1992). This drape has accumulated since**  **the rise in sea level at the end of the Pleistocene (i.e., 12,000 yrs B.P.). The drape is ubiquitous on the continental slope. The presence of this drape over the failure scar and its debris field would indicate the**  **slump is an ancient feature thousands of years old. The lack of drape would indicate that the landslide is a relatively recent feature and slope stability is a concern for this area. The resolution of the 3-D data is not**  **adequate to define the presence or absence of the Holocene pelagic drape in this area. Therefore, the age of the seafloor failures cannot not be assessed with confidence.** 
Deepwater Benthic Communities. **There is no indication of fluids or gas venting from nearby faults at the seabed. Features or areas that could support high-density deepwater benthic communities are not located**  **within 2,000 ft of the proposed location; however, scattered deepwater corals were noted in the ROV data near the KC 692-B well location. These small branching corals exist on soft substrate and are not**  **considered to be high-density benthic communities that are generally associated with hardgrounds. The Seafloor Amplitude Rendering (Map KC692-B-3) shows normal or ambient amplitudes along the seabed at,**  **and near, the proposed wellsite.**
Stratigraphy. **Stratigraphic conditions are shown on Figures KC692-B-1 and KC692-B-2. The seafloor and near-surface sediments at the Proposed Wellsite KC 692-B are expected to be hemipelagic and** **pelagic clays and silty clays. In general, beneath the drape to 374 ft bml the sediments consist of clay prone run-out debris associated with the shallow slope failure approximately 100 ft to the west. The**  **sediments from 374 ft bml to the limit of investigation (5,760 ft bml) are generally composed of hemipelagic clays and clay-rich turbidite deposits interlayered in places with thin debris flow deposits. Thin sand layers**  **are possible within the stratified turbidites and mass-transport deposits.**

Faults. **No seafloor faults are expected to be penetrated by the Proposed Wellsite KC 692-B; however, there are several faults near the proposed surface location along the shallow salt ridge to the west (Figures**  **KC692-B-1 and KC692-B-2). The closest seafloor fault to the proposed wellsite is approximately 2,800 ft to the west. The fault trends northwest-southeast and is downthrown to the east-northeast.** 
**A buried fault lies approximately 340 ft west of the proposed well (Figure KC692-B-1). This fault trends northeast-southwest and is downthrown to the southeast. No other distinct faults were mapped at the**  **Proposed Wellsite KC 692-B; however, the stratigraphic units along the salt ridge to the west are likely to be highly fractured as a result of the past motion of the underlying shallow salt structure. Faults may exist**  **at the proposed location that are beyond the resolution of the data.**

Shallow Gas and Shallow Water Flow. **Significant shallow gas is not expected at this wellsite within the upper 5,760 ft of sediment (Figures KC692-B-1 and KC692-B-2). The potential for shallow water flow at**  **this well location is considered negligible to low (Figure KC692-B-2).**

Shallow Gas. **The potential for encountering shallow gas at the Proposed Wellsite KC 692-B ranges from negligible to low. The well path will not penetrate any high-amplitude events between the seafloor and**  **the limit of investigation (5,760 ft bml), Map KC692-B-4 and Figure KC692-B-2. Various amplitude events Project No. 0412-2080** 

**Chevron U.S.A. Inc. //**  **July 10, 2012**

**Geoscience Earth & Marine Services, Inc. ®** // 4 FORUM ENERGY TECHNOLOGIES, INC. **exist near the proposed well location within debris flow deposits between the seafloor and 374 ft bml (Map KC692-B-4). An increase in amplitude character within this unit likely represents a change in**  **lithology within the debris flow sediments. There is a low potential for encountering shallow gas within this interval. A low potential for encountering shallow gas exists from Horizon 30 (1,251 ft bml) to the limit of**  **investigation (5,760 ft bml). Low- to moderate-amplitude reflectors in places may indicate an increase in minor amounts of biogenic gas within possible thin sand seams within the turbidite and mass-transport**  **deposits.**

Shallow Water Flow **. There is a negligible to low potential for shallow water flow within the sedimentary section from the seafloor to the limit of investigation (5,760 ft bml), Figure KC692-B-2. A low**  **potential for encountering overpressured sands exists within the units from Horizon 10 (840 ft bml) to the limit of investigation (5,760 ft bml). Any sands encountered within the turbidite and mass-transport deposits**  **within these units are expected to be thin seams and not likely to produce sustained flows. No nearby wells reported any shallow water flow conditions and Block KC 692 lies a significant distance downslope**  **from any recognized regional sand-bearing units. Any thin sand seams or silty-sand layers encountered are not expected to be overpressured.**  

### Closing
**The Proposed Wellsite KC 692-B in Keathley Canyon Block 692 generally appears suitable for exploration drilling operations. Engineers should be aware of the 9.9° seafloor slope. We appreciate the opportunity to**  **be of service to Chevron on this project and look forward to working closely with you on other projects. Sincerely,** 

GEOSCIENCE EARTH & MARINE SERVICES, INC. ®

**Carla Cleveland Geoscientist** 

**Erin Williams Janes Daniel Lanier**  **Project Manager - Senior Geoscientist Vice President - Geoscience**

Attachments: **(4 Maps and 2 Figures) Distribution: Mr. Philip Von Dullen III, Chevron U.S.A. Inc., Houston, TX (5 Copies)** 

References:
**Bureau of Ocean Energy Management, 2011, Notice to lessees and operators of federal oil and gas leases and pipeline right-of-way holders on the outer continental shelf, 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 OCS Region, NTL 2011-JOINT-G01.** 
**Bureau of Ocean Energy Management, 2012, ASCII data files, published on the BOEM Gulf of Mexico Region homepage, <http://www.gomr.boem.gov/homepg/pubinfo/freeasci/freedesc.html>, accessed July, 2012.** 
**Bureau of Ocean Energy Management, Regulation, and Enforcement, 2011, Pre-seabed disturbance survey mitigation, released by BOEMRE in March 2011.** 
**Coffeen, J. A., 1978, Seismic Exploration Fundamentals: Tulsa, the Petroleum Publishing Co., p. 125.**
**Doyle, E. H., Kaluza, M. J., and H. H. Roberts, 1992, Use of manned submersibles to investigate slumps in deep water Gulf of Mexico: Proceeding of the 5**  **th International Conference of Civil Engineering in the Oceans, p. 770-782.** 
**GEMS, 2009, Geologic and stratigraphic assessment, blocks 692, 693, 735, 736, and 780, Keathley Canyon Area, Gulf of Mexico, Geoscience Earth & Marine Services, Inc.**  **® , Report No. 0109-1600.** 
**GEMS, 2012, Archaeological ROV assessment Moccasin area “B” Well, block 692, Keathley Canyon Protraction Area, U.S. Gulf of Mexico, February 2012, Geoscience Earth & Marine Services, Inc.**  **® , Report No. 0112-2040.** **Project No. 0412-2080**

**Chevron U.S.A. Inc. //**  **July 10, 2012**

**Geoscience Earth & Marine Services, Inc. ®** // 5 FORUM ENERGY TECHNOLOGIES, INC. **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, Shallow hazards requirements:**  **U. S. Department of the Interior, Minerals Management Service, Gulf of Mexico, NTL 2008-G05.**
**Minerals Management Service, 2008b, 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.** 
**Minerals Management Service, 2008c, 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 Mexico, NTL 2008-G06.**
**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. 10615 Shadow Wood Drive**  **Suite 200 Houston, Texas 77043**  **(713) 468-1410 (o) (713) 468-1438 (f)**  www.gemsinc.com

**Geoscience Earth & Marine Services, Inc. ®** // 1 FORUM ENERGY TECHNOLOGIES, INC. **July 10, 2012 Project No. 0412-2080** 

**C hevron U.S.A. Inc.**  **1500 Louisiana Room 5717F**  **Houston, Texas 77002**
**Attention: Mr. Philip Von Dullen III** 

### Site Clearance Letter Proposed Wellsite KC 692-C Block 692 (OCS G

**-** 25801) Keathley Canyon Area, Gulf of Mexico

**Chevron U.S.A. Inc., (Chevron) plans to drill an exploration well in Block 692 of the Keathley Canyon (KC) Area, Gulf of Mexico. This letter addresses specific seafloor and subsurface geologic conditions to a depth**  **of approximately 6,540 ft below the mudline (bml), at the Proposed Exploration Wellsite KC 692-C. The**  **f ollowing discussion is based on findings provided within the main body of the geohazards report for Blocks**  **KC 692, 693, 735, 736, and 780 and within the archaeological ROV assessment (GEMS Report Nos. 0109-1600 and 0112-2040; GEMS, 2009 and 2012 respectively).** 
**The surface location of the proposed KC 692-C wellsite lies in the central portion of KC 692. Chevron provided the following coordinates:** 



### Proposed Exploration Wellsite KC 692-C

Spheroid & Datum: Clarke 1866, NAD27 Projection: UTM Zone 15 North, U.S. ft Line Reference Block Calls

KC 692
**X: 1,845,947 Latitude: 26o 17' 40.72243" N Inline: 14530 7,333 ft FEL Y: 9,541,656 Longitude: 92o 22' 20.90569" W Crossline: 5757 5,976 ft FSL** 

**Chevron plans to drill this well using a dynamically positioned drilling vessel. Our assessment addresses the seafloor conditions within a 2,000 ft radius around the proposed wellsite location.** 



### Attachments
**The page-size 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 No. KC692-C-1. Bathymetry Map**

• **Map No. KC692-C-2. Seafloor Rendering**

• **Map No. KC692-C-3. Seafloor Amplitude Rendering**

• **Map No. KC692-C-4. Geologic Features Map**

• **Figure KC692-C-1. Portions of Inline 14530 and Crossline 5757 Showing Conditions Beneath Proposed Wellsite KC 692-C** 

• **Figure KC692-C-2. Tophole Prognosis Chart, Proposed Wellsite KC 692-C, Keathley Canyon Area, Block 692** **Project No. 0412-2080**

**Chevron U.S.A. Inc. //**  **July 10, 2012**

**Geoscience Earth & Marine Services, Inc. ®** // 2 FORUM ENERGY TECHNOLOGIES, INC. 

### NTL Requirements
**The following report complies with the Bureau of Ocean Energy Management (BOEM, formerly MMS) Notice to Lessees (NTL’s) 2008-G05 and 2009-G40 (MMS, 2008a and 2010). The operator will be required** **to follow NTL’s 2008-G04 and -G06 with respect to an ROV monitoring survey as well as pre- and post spud ROV visual inspection surveys (MMS, 2008b and 2008c).** 
**The Federal lease Block KC 692 is not considered archaeologically significant (BOEM, 2011); however, pursuant to the “Pre-Seabed Disturbance Survey Mitigation” released by the BOEMRE in March 2011**  **(BOEMRE, 2011), an archaeological assessment of the well location will be required before any bottom disturbing activities. GEMS submitted an archaeological ROV assessment for Keathley Canyon Block 692**  **to Chevron in March 2012 (GEMS, 2012). This archaeological ROV assessment satisfies the BOEMRE requirement.** 
Power Spectrum. **According to NTL 2008-G05 (MMS, 2008a), 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 Chevron 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. 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, KC 692, Proposed Wellsite KC 692-C



### Man-Made Features
**The KC 736 #1 well was drilled by Chevron in 2010 in the southern portion of KC 736, approximately 4.0 miles south-southwest of the proposed well location. The KC 736 #1 well is permanently abandoned.**  **There are no existing pipelines, cables, or platforms within KC 692 or in the immediate surrounding blocks (BOEM, 2012).**  **0 0.1**  **0.2 0.3**  **0.4 0.5**  **0.6 0.7**  **0.8 0.9**  **1**

**0 10 20 30 40 50 60 70 80 90 100**Power (Amp2)

Frequency (Hz) POWER SPECTRUM**Project No. 0412-2080**

**Chevron U.S.A. Inc. //**  **July 10, 2012**

**Geoscience Earth & Marine Services, Inc. ®** // 3 FORUM ENERGY TECHNOLOGIES, INC. 

### Wellsite Conditions
**The surface location is clear of any constraining geologic conditions within a 2,000-ft radius from the proposed wellsite.** 
Water Depth, Slope, and Seafloor Sediments. **Seafloor conditions are favorable for exploration drilling at the proposed wellsite location. The water depth at the proposed surface location is approximately -6,710 ft**  **(Map KC692-C-1). The seafloor at the proposed wells ite is slightly irregular, and dips to the east-northeast** **at about 3.5°. The ROV data shows little perceptible relief along the proposed well location. The near surface sediments are expected to be normally consolidated clays forming a drape over the area. The**  **Proposed Wellsite KC 692-C is situated along the flank of an expansive shallow salt ridge. The seafloor along the salt ridge is irregular as a result of numerous fault scarps, seafloor failures, and the deformation**  **of the shallow overburden by the underlying salt (Map KC692-C-2).**
Deepwater Benthic Communities. **There is no indication of fluids or gas venting from nearby faults at the seabed. Features or areas that could support high-density deepwater benthic communities are not located**  **within 2,000 ft of the proposed location; however, scattered deepwater corals were noted in the ROV data near the KC 692-C survey location. These small branching corals exist on soft substrate and are not**  **considered to be high-density benthic communities that are generally associated with hardgrounds. The Seafloor Amplitude Rendering (Map KC692-C-3) shows normal or ambient amplitudes along the seabed at,**  **and near, the proposed wellsite.**
Stratigraphy. **Stratigraphic conditions are shown on Figures KC692-C-1 and KC692-C-2. The seafloor at and near-surface sediments at the Proposed Wellsite KC 692-C are expected to be hemipelagic and**  **pelagic clays and silty clays. In general, the sediments between the seafloor and the limit of investigation (6,540 ft bml) consist of hemipelagic clays and clay-rich turbidite deposits interlayered in places with thin**  **debris flow deposits. Thin sand layers are possible within the stratified turbidites and mass-transport deposits.** 

Faults. **Several seafloor and buried faults exist near the proposed well location along the shallow salt ridge. A vertical borehole will intersect a seafloor fault at approximately 649 ft bml (Figures KC692-C-1 and**  **KC692-C-2). The fault is located about 600 ft to the southwest, trends northwest-southeast, and is downthrown to the northeast. The fault exhibits approximately 5 ft of relief. The offset of the seafloor**  **implies that motion along the fault is probably still occurring, but at rates analogous to soil creep.**
**A vertical borehole will intersect two buried faults at 357 ft and 1,042 ft bml (Figures KC692-C-1 and KC692-C-2). These faults trend northwest-southeast and are downthrown to the northeast. No other**  **distinct faults were mapped at the Proposed Wellsite KC 692-C; however, the stratigraphic units along the salt ridge are likely to be highly fractured as a result of the past motion of the underlying shallow salt**  **structure. Faults may exist at the proposed location that are beyond the resolution of the data.**

Shallow Gas and Shallow Water Flow. **Significant shallow gas is not expected at this wellsite within the upper 6,540 ft of sediment (Figures KC692-C-1 and KC692-C-2). The potential for shallow water flow at**  **this well location is considered negligible to low (Figure KC692-C-2).**

Shallow Gas. **The potential for encountering shallow gas at the Proposed Wellsite KC 692-C ranges**  **from negligible to low. The well path will not penetrate any high-amplitude events between the seafloor and the limit of investigation (6,540 ft bml), Map KC692-C-4 and Figure KC692-C-2. A low potential for**  **encountering shallow gas exists from 1,739 ft bml to the limit of investigation (6,540 ft bml). Low- to moderate-amplitude reflectors in places may indicate an increase in minor amounts of biogenic gas within**  **possible thin sand seams within the turbidite and mass-transport deposits. There is a negligible potential for encountering shallow gas between the seafloor and 1,739 ft bml.** 

Shallow Water Flow **. There is a negligible to low potential for shallow water flow within the sedimentary section from the seafloor to the limit of investigation (6,540 ft bml), Figure KC692-C-2. A low**  **potential for encountering overpressured sands exists within the units from 1,042 ft bml to the limit of investigation (6,540 ft bml). Any sands encountered within the turbidite and mass-transport deposits within**  **these units are expected to be thin seams and not likely to produce sustained flows. No nearby wells reported any shallow water flow conditions and Block KC 692 lies a significant distance downslope from**  **any recognized regional sand-bearing units. Any thin sand seams or silty-sand layers encountered are not expected to be overpressured.** **Project No. 0412-2080**

**Chevron U.S.A. Inc. //**  **July 10, 2012**

**Geoscience Earth & Marine Services, Inc. ®** // 4 FORUM ENERGY TECHNOLOGIES, INC. 

### Closing
**The Proposed Wellsite KC 692-C in Keathley Canyon Block 692 appears suitable for exploration drilling operations. We appreciate the opportunity to be of service to Chevron on this project and look forward to**  **working closely with you on other projects. Sincerely,** 

GEOSCIENCE EARTH & MARINE SERVICES, INC. ®

**Carla Cleveland Geoscientist** 

**Erin Williams Janes Daniel Lanier**  **Project Manager - Senior Geoscientist Vice President - Geoscience**

Attachments: **(4 Maps and 2 Figures) Distribution: Mr. Philip Von Dullen III, Chevron U.S.A. Inc., Houston, TX (5 Copies)** 



### References:

**Bureau of Ocean Energy Management, 2011, Notice to lessees and operators of federal oil and gas leases and pipeline right-of-way holders on the outer continental shelf, 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 OCS Region, NTL 2011-JOINT-G01.** 
**Bureau of Ocean Energy Management, 2012, ASCII data files, published on the BOEM Gulf of Mexico Region homepage, <http://www.gomr.boem.gov/homepg/pubinfo/freeasci/freedesc.html>, accessed July, 2012.** 
**Bureau of Ocean Energy Management, Regulation, and Enforcement, 2011, Pre-seabed disturbance survey mitigation, released by BOEMRE in March 2011.** 
**Coffeen, J. A., 1978, Seismic Exploration Fundamentals: Tulsa, the Petroleum Publishing Co., p. 125.**
**GEMS, 2009, Geologic and stratigraphic assessment, blocks 692, 693, 735, 736, and 780, Keathley Canyon Area, Gulf of Mexico, Geoscience Earth & Marine Services, Inc.**  **® , Report No. 0109-1600.** 
**GEMS, 2012, Archaeological ROV assessment Moccasin area “C” Well, block 692, Keathley Canyon Protraction Area, U.S. Gulf of Mexico, February 2012, Geoscience Earth & Marine Services, Inc.**  **® , Report No. 0112-2040.** 
**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, Shallow hazards requirements:**  **U. S. Department of the Interior, Minerals Management Service, Gulf of Mexico, NTL 2008-G05.**
**Minerals Management Service, 2008b, 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.** 
**Minerals Management Service, 2008c, 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 Mexico, NTL 2008-G06.**
**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. 10615 Shadow Wood Drive**  **Suite 200 Houston, Texas 77043**  **(713) 468-1410 (o) (713) 468-1438 (f)**  www.gemsinc.com

**Geoscience Earth & Marine Services, Inc. ®** // 1 FORUM ENERGY TECHNOLOGIES, INC. **July 10, 2012 Project No. 0412-2080** 

**C hevron U.S.A. Inc.**  **1500 Louisiana Room 5717F**  **Houston, Texas 77002**
**Attention: Mr. Philip Von Dullen III** 

### Site Clearance Letter Proposed Wellsite KC 692-D Block 692 (OCS G

**-** 25801) Keathley Canyon Area, Gulf of Mexico

**Chevron U.S.A. Inc., (Chevron) plans to drill an exploration well in Block 692 of the Keathley Canyon (KC) Area, Gulf of Mexico. This letter addresses specific seafloor and subsurface geologic conditions to a depth**  **of approximately 6,285 ft below the mudline (bml), at the Proposed Exploration Wellsite KC 692-D. The**  **f ollowing discussion is based on findings provided within the main body of the geohazards report for Blocks**  **KC 692, 693, 735, 736, and 780 and within the archaeological ROV assessment (GEMS Report Nos. 0109-1600 and 0112-2040; GEMS, 2009 and 2012 respectively).** 
**The surface location of the proposed KC 692-D wellsite lies in the southeastern portion of KC 692. Chevron provided the following coordinates:** 



### Proposed Exploration Wellsite KC 692-D

Spheroid & Datum: Clarke 1866, NAD27 Projection: UTM Zone 15 North, U.S. ft Line Reference Block Calls

KC 692
**X: 1,848,043 Latitude: 26o 17' 20.01312" N Inline: 14375 5,237 ft FEL Y: 9,539,576 Longitude: 92o 21' 57.98059" W Crossline: 5808 3,896 ft FSL** 

**Chevron plans to drill this well using a dynamically positioned drilling vessel. Our assessment addresses the seafloor conditions within a 2,000 ft radius around the proposed wellsite location.** 



### Attachments
**The page-size 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 No. KC692-D-1. Bathymetry Map**

• **Map No. KC692-D-2. Seafloor Rendering**

• **Map No. KC692-D-3. Seafloor Amplitude Rendering**

• **Map No. KC692-D-4. Geologic Features Map**

• **Figure KC692-D-1. Portions of Inline 14375 and Crossline 5808 Showing Conditions Beneath Proposed Wellsite KC 692-D** 

• **Figure KC692-D-2. Tophole Prognosis Chart, Proposed Wellsite KC 692-D, Keathley Canyon Area, Block 692** **Project No. 0412-2080**

**Chevron U.S.A. Inc. //**  **July 10, 2012**

**Geoscience Earth & Marine Services, Inc. ®** // 2 FORUM ENERGY TECHNOLOGIES, INC. 

### NTL Requirements
**The following report complies with the Bureau of Ocean Energy Management (BOEM, formerly MMS) Notice to Lessees (NTL’s) 2008-G05 and 2009-G40 (MMS, 2008a and 2010). The operator will be required** **to follow NTL’s 2008-G04 and -G06 with respect to an ROV monitoring survey as well as pre- and post spud ROV visual inspection surveys (MMS, 2008b and 2008c).** 
**The Federal lease Block KC 692 is not considered archaeologically significant (BOEM, 2011); however, pursuant to the “Pre-Seabed Disturbance Survey Mitigation” released by the BOEMRE in March 2011**  **(BOEMRE, 2011), an archaeological assessment of the well location will be required before any bottom disturbing activities. GEMS submitted an archaeological ROV assessment for Keathley Canyon Block 692**  **to Chevron in March 2012 (GEMS, 2012). This archaeological ROV assessment satisfies the BOEMRE requirement.** 
Power Spectrum. **According to NTL 2008-G05 (MMS, 2008a), 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 Chevron 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. 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, KC 692, Proposed Wellsite KC 692-D



### Man-Made Features
**The KC 736 #1 well was drilled by Chevron in 2010 in the southern portion of KC 736, approximately 3.7 miles southwest of the proposed well location. The KC 736 #1 well is permanently abandoned. There**  **are no existing pipelines, cables, or platforms within KC 692 or in the immediate surrounding blocks (BOEM, 2012).** 

**0 0.1**  **0.2 0.3**  **0.4 0.5**  **0.6 0.7**  **0.8 0.9**  **1**

**0 10 20 30 40 50 60 70 80 90 100**Power (Amp2)

Frequency (Hz) POWER SPECTRUM**Project No. 0412-2080**

**Chevron U.S.A. Inc. //**  **July 10, 2012**

**Geoscience Earth & Marine Services, Inc. ®** // 3 FORUM ENERGY TECHNOLOGIES, INC. 

### Wellsite Conditions
**The surface location is clear of any constraining geologic conditions within a 2,000-ft radius from the proposed wellsite.** 
Water Depth, Slope, and Seafloor Sediments. **Seafloor conditions are favorable for exploration drilling at the proposed wellsite location. The water depth at the proposed surface location is approximately -6,848 ft**  **(Map KC692-D-1). The seafloor at the proposed wells ite is generally smooth, and dips to the east**  **northeast at about 8.6°. The ROV data confirms a relatively smooth mud bottom across the proposed well location. The near-surface sediments are expected to be normally consolidated clays forming a drape over**  **the area. The Proposed Wellsite KC 692-D is situated along the flank of a broad intraslope basin named Chalmette Basin. An expansive shallow salt ridge lies approximately 500 ft west-southwest of the**  **proposed well location. The seafloor along the salt ridge is irregular as a result of numerous fault scarps, seafloor failures, and the deformation of the shallow overburden by the underlying salt (Map KC692-D-2).** 
Deepwater Benthic Communities. **There is no indication of fluids or gas venting from nearby faults at the seabed. Features or areas that could support high-density deepwater benthic communities are not located**  **within 2,000 ft of the proposed location; however, scattered deepwater corals were noted in the ROV data near the KC 692-D survey location. These small branching corals exist on soft substrate and are not**  **considered to be high-density benthic communities that are generally associated with hardgrounds. The Seafloor Amplitude Rendering (Map KC692-D-3) shows normal or ambient amplitudes along the seabed at,**  **and near, the proposed wellsite.**
Stratigraphy. **Stratigraphic conditions are shown on Figures KC692-D-1 and KC692-D-2. The seafloor at and near-surface sediments at the Proposed Wellsite KC 692-D are expected to be hemipelagic and**  **pelagic clays and silty clays. In general, the sediments between the seafloor and the limit of investigation (6,285 ft bml) consist of hemipelagic clays and clay-rich turbidite deposits interlayered in places with thin**  **debris flow deposits. Thin sand layers are possible within the stratified turbidites and mass-transport deposits.** 

Faults. **No seafloor faults are expected to be penetrated by the Proposed Wellsite KC 692-D; however, there are several faults near the proposed surface location along the shallow salt ridge to the west (Figures**  **KC692-D-1 and KC692-D-2). The closest seafloor fault to the proposed wellsite is approximately 1,475 ft to the northwest. The fault trends northwest-southeast and is downthrown to the east-northeast.** 
**A vertical borehole will intersect three buried faults at 571 ft, 1,062 ft, and 1,724 ft bml (Figures KC692-D-1 and KC692-D-2). These faults trend northwest-southeast and are downthrown to the northeast. No other**  **distinct faults were mapped at the Proposed Wellsite KC 692-D; however, the stratigraphic units along the salt ridge to the west are likely to be highly fractured as a result of the past motion of the underlying shallow**  **salt structure. Faults may exist at the proposed location that are beyond the resolution of the data.**

Shallow Gas and Shallow Water Flow. **Significant shallow gas is not expected at this wellsite within the upper 6,285 ft of sediment (Figures KC692-D-1 and KC692-D-2). The potential for shallow water flow at**  **this well location is considered negligible to low (Figure KC692-D-2).**

Shallow Gas. **The potential for encountering shallow gas at the Proposed Wellsite KC 692-D ranges from negligible to low. The well path will not penetrate any high-amplitude events between the seafloor and**  **the limit of investigation (6,285 ft bml), Map KC692-D-4 and Figure KC692-D-2. A low potential for encountering shallow gas exists from 2,089 ft bml to the limit of investigation (6,285 ft bml). Low- to**  **moderate-amplitude reflectors in places may indicate an increase in minor amounts of biogenic gas within possible thin sand seams within the turbidite and mass-transport deposits. There is a negligible potential**  **for encountering shallow gas between the seafloor and 2,089 ft bml.**

Shallow Water Flow **. There is a negligible to low potential for shallow water flow within the sedimentary section from the seafloor to the limit of investigation (6,285 ft bml), Figure KC692-D-2. A low**  **potential for encountering overpressured sands exists within the units from 1,062 ft bml to the limit of investigation (6,285 ft bml). Any sands encountered within the turbidite and mass-transport deposits within**  **these units are expected to be thin seams and not likely to produce sustained flows. No nearby wells reported any shallow water flow conditions and Block KC 692 lies a significant distance downslope from**  **any recognized regional sand-bearing units. Any thin sand seams or silty-sand layers encountered are not expected to be overpressured.** **Project No. 0412-2080**

**Chevron U.S.A. Inc. //**  **July 10, 2012**

**Geoscience Earth & Marine Services, Inc. ®** // 4 FORUM ENERGY TECHNOLOGIES, INC. 

### Closing
**The Proposed Wellsite KC 692-D in Keathley Canyon Block 692 appears suitable for exploration drilling operations. We appreciate the opportunity to be of service to Chevron on this project and look forward to**  **working closely with you on other projects. Sincerely,** 

GEOSCIENCE EARTH & MARINE SERVICES, INC. ®

**Carla Cleveland Geoscientist** 

**Erin Williams Janes Daniel Lanier**  **Project Manager - Senior Geoscientist Vice President - Geoscience**

Attachments: **(4 Maps and 2 Figures) Distribution: Mr. Philip Von Dullen III, Chevron U.S.A. Inc., Houston, TX (5 Copies)** 



### References:

**Bureau of Ocean Energy Management, 2011, Notice to lessees and operators of federal oil and gas leases and pipeline right-of-way holders on the outer continental shelf, 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 OCS Region, NTL 2011-JOINT-G01.** 
**Bureau of Ocean Energy Management, 2012, ASCII data files, published on the BOEM Gulf of Mexico Region homepage, <http://www.gomr.boem.gov/homepg/pubinfo/freeasci/freedesc.html>, accessed July, 2012.** 
**Bureau of Ocean Energy Management, Regulation, and Enforcement, 2011, Pre-seabed disturbance survey mitigation, released by BOEMRE in March 2011.** 
**Coffeen, J. A., 1978, Seismic Exploration Fundamentals: Tulsa, the Petroleum Publishing Co., p. 125.**
**GEMS, 2009, Geologic and stratigraphic assessment, blocks 692, 693, 735, 736, and 780, Keathley Canyon Area, Gulf of Mexico, Geoscience Earth & Marine Services, Inc.**  **® , Report No. 0109-1600.** 
**GEMS, 2012, Archaeological ROV assessment Moccasin area “D” Well, block 692, Keathley Canyon Protraction Area, U.S. Gulf of Mexico, February 2012, Geoscience Earth & Marine Services, Inc.**  **® , Report No. 0112-2040.** 
**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, Shallow hazards requirements:**  **U. S. Department of the Interior, Minerals Management Service, Gulf of Mexico, NTL 2008-G05.**
**Minerals Management Service, 2008b, 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.** 
**Minerals Management Service, 2008c, 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 Mexico, NTL 2008-G06.**
**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. 10615 Shadow Wood Drive**  **Suite 200 Houston, Texas 77043**  **(713) 468-1410 (o) (713) 468-1438 (f)**  www.gemsinc.com

**Geoscience Earth & Marine Services, Inc. ®** // 1 FORUM ENERGY TECHNOLOGIES, INC. **July 10, 2012 Project No. 0412-2080** 

**C hevron U.S.A. Inc.**  **1500 Louisiana Room 5717F**  **Houston, Texas 77002**
**Attention: Mr. Philip Von Dullen III** 

### Site Clearance Letter Proposed Wellsite KC 692-E Block 692 (OCS G

**-** 25801) Keathley Canyon Area, Gulf of Mexico

**Chevron U.S.A. Inc., (Chevron) plans to drill an exploration well in Block 692 of the Keathley Canyon (KC) Area, Gulf of Mexico. This letter addresses specific seafloor and subsurface geologic conditions to a depth**  **of approximately 5,528 ft below the mudline (bml), at the Proposed Exploration Wellsite KC 692-E. The**  **f ollowing discussion is based on findings provided within the main body of the geohazards report for Blocks**  **KC 692, 693, 735, 736, and 780 and within the archaeological ROV assessment (GEMS Report Nos. 0109-1600 and 0112-2040; GEMS, 2009 and 2012 respectively).** 
**The surface location of the proposed KC 692-E wellsite lies in the southeastern portion of KC 692. Chevron provided the following coordinates:** 



### Proposed Exploration Wellsite KC 692-E

Spheroid & Datum: Clarke 1866, NAD27 Projection: UTM Zone 15 North, U.S. ft Line Reference Block Calls

KC 692
**X: 1,850,412 Latitude: 26o 17' 15.72631" N Inline: 14340 2,868 ft FEL Y: 9,539,155 Longitude: 92o 21' 31.96715" W Crossline: 5866 3,475 ft FSL** 

**Chevron plans to drill this well using a dynamically positioned drilling vessel. Our assessment addresses the seafloor conditions within a 2,000 ft radius around the proposed wellsite location.** 



### Attachments
**The page-size 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 No. KC692-E-1. Bathymetry Map**

• **Map No. KC692-E-2. Seafloor Rendering**

• **Map No. KC692-E-3. Seafloor Amplitude Rendering**

• **Map No. KC692-E-4. Geologic Features Map**

• **Figure KC692-E-1. Portions of Inline 14340 and Crossline 5866 Showing Conditions Beneath Proposed Wellsite KC 692-E** 

• **Figure KC692-E-2. Tophole Prognosis Chart, Proposed Wellsite KC 692-E, Keathley Canyon Area, Block 692** **Project No. 0412-2080**

**Chevron U.S.A. Inc. //**  **July 10, 2012**

**Geoscience Earth & Marine Services, Inc. ®** // 2 FORUM ENERGY TECHNOLOGIES, INC. 

### NTL Requirements
**The following report complies with the Bureau of Ocean Energy Management (BOEM, formerly MMS) Notice to Lessees (NTL’s) 2008-G05 and 2009-G40 (MMS, 2008a and 2010). The operator will be required** **to follow NTL’s 2008-G04 and -G06 with respect to an ROV monitoring survey as well as pre- and post spud ROV visual inspection surveys (MMS, 2008b and 2008c).** 
**The Federal lease Block KC 692 is not considered archaeologically significant (BOEM, 2011); however, pursuant to the “Pre-Seabed Disturbance Survey Mitigation” released by the BOEMRE in March 2011**  **(BOEMRE, 2011), an archaeological assessment of the well location will be required before any bottom disturbing activities. GEMS submitted an archaeological ROV assessment for Keathley Canyon Block 692**  **to Chevron in March 2012 (GEMS, 2012). This archaeological ROV assessment satisfies the BOEMRE requirement.** 
Power Spectrum. **According to NTL 2008-G05 (MMS, 2008a), 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 Chevron 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. 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, KC 692, Proposed Wellsite KC 692-E



### Man-Made Features
**The KC 736 #1 well was drilled by Chevron in 2010 in the southern portion of KC 736, approximately 3.7 miles southwest of the proposed well location. The KC 736 #1 well is permanently abandoned. There**  **are no existing pipelines, cables, or platforms within KC 692 or in the immediate surrounding blocks (BOEM, 2012).** 

**0 0.1**  **0.2 0.3**  **0.4 0.5**  **0.6 0.7**  **0.8 0.9**  **1**

**0 10 20 30 40 50 60 70 80 90 100**Power (Amp2)

Frequency (Hz) POWER SPECTRUM**Project No. 0412-2080**

**Chevron U.S.A. Inc. //**  **July 10, 2012**

**Geoscience Earth & Marine Services, Inc. ®** // 3 FORUM ENERGY TECHNOLOGIES, INC. 

### Wellsite Conditions
**The surface location is clear of any constraining geologic conditions within a 2,000-ft radius from the proposed wellsite.** 
Water Depth, Slope, and Seafloor Sediments. **Seafloor conditions are generally favorable for exploration drilling at the proposed wellsite location. The water depth at the proposed surface location is approximately**  **-7,251 ft (Map KC692-E-1). The seafloor at the proposed wells**  **ite is generally smooth, and dips to the east northeast at a fairly steep inclination of 11.9°. The ROV data confirms a relatively smooth mud bottom**  **across the proposed well location. The near-surface sediments are expected to be normally consolidated clays forming a drape over the area. The Proposed Wellsite KC 692-E is situated along the flank of a**  **broad intraslope basin named Chalmette Basin. An expansive shallow salt ridge lies approximately 2,200 ft west-southwest of the proposed well location. The seafloor along the salt ridge is irregular as a result of**  **numerous fault scarps, seafloor failures, and the deformation of the shallow overburden by the underlying salt (Map KC692-E-2).** 
**A shallow slope failure scarp lies approximately 2,000 ft to the west of the proposed location. Relief along the failure scar ranges from about 15 ft to 30 ft. Slopes across the scarp vary from approximately 7° to 25°.**  **Throughout the northern Gulf of Mexico continental slope region, many slope failures are covered with a surficial drape of Holocene-aged pelagic sediments (Doyle et al., 1992). This drape has accumulated since**  **the rise in sea level at the end of the Pleistocene (i.e., 12,000 yrs B.P.). The drape is ubiquitous on the continental slope. The presence of this drape over the failure scar and its debris field would indicate the**  **slump is an ancient feature thousands of years old. The lack of drape would indicate that the landslide is a relatively recent feature and slope stability is a concern for this area. The resolution of the 3-D data is not**  **adequate to define the presence or absence of the Holocene pelagic drape in this area. Therefore, the age of the seafloor failures cannot not be assessed with confidence.** 
Deepwater Benthic Communities. **There is no indication of fluids or gas venting from nearby faults at the seabed. Features or areas that could support high-density deepwater benthic communities are not located**  **within 2,000 ft of the proposed location; however, scattered deepwater corals were noted in the ROV data near the KC 692-E survey location. These small branching corals exist on soft substrate and are not**  **considered to be high-density benthic communities that are generally associated with hardgrounds. The Seafloor Amplitude Rendering (Map KC692-E-3) shows normal or ambient amplitudes along the seabed at,**  **and near, the proposed wellsite.**
Stratigraphy. **Stratigraphic conditions are shown on Figures KC692-E-1 and KC692-E-2. The seafloor and near-surface sediments at the Proposed Wellsite KC 692-E are expected to be hemipelagic and** **pelagic clays and silty clays. In general, the sediments between the seafloor 271 ft bml consist of clay prone run-out debris associated with the shallow slope failure approximately 2,000 ft to the west. The**  **sediments from 271 ft bml to the limit of investigation (5,528 ft bml) is generally composed of hemipelagic clays and clay-rich turbidite deposits interlayered in places with thin debris flow deposits. Thin sand layers**  **are possible within the stratified turbidites and mass-transport deposits.**

Faults. **No seafloor faults are expected to be penetrated by the Proposed Wellsite KC 692-E; however, there are several faults near the proposed surface location along the shallow salt ridge (Figures KC692-E-1**  **and KC692-E-2). The closest seafloor fault to the proposed wellsite is approximately 3,000 ft to the west. The fault trends northwest-southeast and is downthrown to the east-northeast.** 
**No other distinct faults were mapped at the Proposed Wellsite KC 692-E; however, the stratigraphic units along the salt ridge to the west are likely to be highly fractured as a result of the past motion of the**  **underlying shallow salt structure. Faults may exist at the proposed location that are beyond the resolution of the data.** 

Shallow Gas and Shallow Water Flow. **Significant shallow gas is not expected at this wellsite within the upper 5,528 ft of sediment (Figures KC692-E-1 and KC692-E-2). The potential for shallow water flow at**  **this well location is considered negligible to low (Figure KC692-E-2).**

Shallow Gas. **The potential for encountering shallow gas at the Proposed Wellsite KC 692-E ranges from negligible to low. The well path will not penetrate any high-amplitude events between the seafloor and**  **the limit of investigation (5,528 ft bml), Map KC692-E-4 and Figure KC692-E-2. Various amplitude events exist near the proposed well location within debris flow deposits between the seafloor and 271 ft bml** **Project No. 0412-2080**

**Chevron U.S.A. Inc. //**  **July 10, 2012**

**Geoscience Earth & Marine Services, Inc. ®** // 4 FORUM ENERGY TECHNOLOGIES, INC. **(Map KC692-E-4). An increase in amplitude character within this unit likely represents a change in lithology within the debris flow sediments. There is a low potential for encountering shallow gas within this**  **interval. A low potential for encountering shallow gas exists from Horizon 30 (1,792 ft bml) to the limit of investigation (5,528 ft bml). Low- to moderate-amplitude reflectors in places may indicate an increase in**  **minor amounts of biogenic gas within possible thin sand seams within the turbidite and mass-transport deposits.** 

Shallow Water Flow **. There is a negligible to low potential for shallow water flow within the sedimentary section from the seafloor to the limit of investigation (5,528 ft bml), Figure KC692-E-2. A low**  **potential for encountering overpressured sands exists within the units from Horizon 10 (924 ft bml) to the limit of investigation (5,528 ft bml). Any sands encountered within the turbidite and mass-transport deposits**  **within these units are expected to be thin seams and not likely to produce sustained flows. No nearby wells reported any shallow water flow conditions and Block KC 692 lies a significant distance downslope**  **from any recognized regional sand-bearing units. Any thin sand seams or silty-sand layers encountered are not expected to be overpressured.**  

### Closing
**The Proposed Wellsite KC 692-E in Keathley Canyon Block 692 generally appears suitable for exploration drilling operations. Engineers should be aware of the 11.9° seafloor slope. We appreciate the opportunity**  **to be of service to Chevron on this project and look forward to working closely with you on other projects. Sincerely,** 

GEOSCIENCE EARTH & MARINE SERVICES, INC. ®

**Carla Cleveland Geoscientist** 

**Erin Williams Janes Daniel Lanier**  **Project Manager - Senior Geoscientist Vice President - Geoscience**

Attachments: **(4 Maps and 2 Figures) Distribution: Mr. Philip Von Dullen III, Chevron U.S.A. Inc., Houston, TX (5 Copies)** 



### References:

**Bureau of Ocean Energy Management, 2011, Notice to lessees and operators of federal oil and gas leases and pipeline right-of-way holders on the outer continental shelf, 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 OCS Region, NTL 2011-JOINT-G01.** 
**Bureau of Ocean Energy Management, 2012, ASCII data files, published on the BOEM Gulf of Mexico Region homepage, <http://www.gomr.boem.gov/homepg/pubinfo/freeasci/freedesc.html>, accessed July, 2012.** 
**Bureau of Ocean Energy Management, Regulation, and Enforcement, 2011, Pre-seabed disturbance survey mitigation, released by BOEMRE in March 2011.** 
**Coffeen, J. A., 1978, Seismic Exploration Fundamentals: Tulsa, the Petroleum Publishing Co., p. 125.**
**Doyle, E. H., Kaluza, M. J., and H. H. Roberts, 1992, Use of manned submersibles to investigate slumps in deep water Gulf of Mexico: Proceeding of the 5**  **th International Conference of Civil Engineering in the Oceans, p. 770-782.** 
**GEMS, 2009, Geologic and stratigraphic assessment, blocks 692, 693, 735, 736, and 780, Keathley Canyon Area, Gulf of Mexico, Geoscience Earth & Marine Services, Inc.**  **® , Report No. 0109-1600.** 
**GEMS, 2012, Archaeological ROV assessment Moccasin area “E” Well, block 692, Keathley Canyon Protraction Area, U.S. Gulf of Mexico, February 2012, Geoscience Earth & Marine Services, Inc.**  **® , Report No. 0112-2040.** **Project No. 0412-2080**

**Chevron U.S.A. Inc. //**  **July 10, 2012**

**Geoscience Earth & Marine Services, Inc. ®** // 5 FORUM ENERGY TECHNOLOGIES, INC. **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, Shallow hazards requirements:**  **U. S. Department of the Interior, Minerals Management Service, Gulf of Mexico, NTL 2008-G05.**
**Minerals Management Service, 2008b, 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.** 
**Minerals Management Service, 2008c, 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 Mexico, NTL 2008-G06.**
**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. 10615 Shadow Wood Drive**  **Suite 200 Houston, Texas 77043**  **(713) 468-1410 (o) (713) 468-1438 (f)**  www.gemsinc.com

**Geoscience Earth & Marine Services, Inc. ®** // 1 FORUM ENERGY TECHNOLOGIES, INC. **July 10, 2012 Project No. 0412-2080** 

**C hevron U.S.A. Inc.**  **1500 Louisiana Room 5717F**  **Houston, Texas 77002**
**Attention: Mr. Philip Von Dullen III** 

### Site Clearance Letter Proposed Wellsite KC 692-F Block 692 (OCS G

**-** 25801) Keathley Canyon Area, Gulf of Mexico

**Chevron U.S.A. Inc., (Chevron) plans to drill an exploration well in Block 692 of the Keathley Canyon (KC) Area, Gulf of Mexico. This letter addresses specific seafloor and subsurface geologic conditions to a depth**  **of approximately 5,299 ft below the mudline (bml), at the Proposed Exploration Wellsite KC 692-F. The**  **f ollowing discussion is based on findings provided within the main body of the geohazards report for Blocks**  **KC 692, 693, 735, 736, and 780 and within the archaeological ROV assessment (GEMS Report Nos. 0109-1600 and 0112-2040; GEMS, 2009 and 2012 respectively).** 
**The surface location of the proposed KC 692-F wellsite lies in the southeastern portion of KC 692. Chevron provided the following coordinates:** 



### Proposed Exploration Wellsite KC 692-F

Spheroid & Datum: Clarke 1866, NAD27 Projection: UTM Zone 15 North, U.S. ft Line Reference Block Calls

KC 692
**X: 1,851,302 Latitude: 26o 17' 05.03174" N Inline: 14260 1,978 ft FEL Y: 9,538,080 Longitude: 92o 21' 22.24456" W Crossline: 5887 2,400 ft FSL** 

**Chevron plans to drill this well using a dynamically positioned drilling vessel. Our assessment addresses the seafloor conditions within a 2,000 ft radius around the proposed wellsite location.** 



### Attachments
**The page-size 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 No. KC692-F-1. Bathymetry Map**

• **Map No. KC692-F-2. Seafloor Rendering**

• **Map No. KC692-F-3. Seafloor Amplitude Rendering**

• **Map No. KC692-F-4. Geologic Features Map**

• **Figure KC692-F-1. Portions of Inline 14260 and Crossline 5887 Showing Conditions Beneath Proposed Wellsite KC 692-F** 

• **Figure KC692-F-2. Tophole Prognosis Chart, Proposed Wellsite KC 692-F, Keathley Canyon Area, Block 692** **Project No. 0412-2080**

**Chevron U.S.A. Inc. //**  **July 10, 2012**

**Geoscience Earth & Marine Services, Inc. ®** // 2 FORUM ENERGY TECHNOLOGIES, INC. 

### NTL Requirements
**The following report complies with the Bureau of Ocean Energy Management (BOEM, formerly MMS) Notice to Lessees (NTL’s) 2008-G05 and 2009-G40 (MMS, 2008a and 2010). The operator will be required** **to follow NTL’s 2008-G04 and -G06 with respect to an ROV monitoring survey as well as pre- and post spud ROV visual inspection surveys (MMS, 2008b and 2008c).** 
**The Federal lease Block KC 692 is not considered archaeologically significant (BOEM, 2011); however, pursuant to the “Pre-Seabed Disturbance Survey Mitigation” released by the BOEMRE in March 2011**  **(BOEMRE, 2011), an archaeological assessment of the well location will be required before any bottom disturbing activities. GEMS submitted an archaeological ROV assessment for Keathley Canyon Block 692**  **to Chevron in March 2012 (GEMS, 2012). This archaeological ROV assessment satisfies the BOEMRE requirement.** 
Power Spectrum. **According to NTL 2008-G05 (MMS, 2008a), 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 Chevron 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. 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, KC 692, Proposed Wellsite KC 692-F



### Man-Made Features
**The KC 736 #1 well was drilled by Chevron in 2010 in the southern portion of KC 736, approximately 3.6 miles southwest of the proposed well location. The KC 736 #1 well is permanently abandoned. There**  **are no existing pipelines, cables, or platforms within KC 692 or in the immediate surrounding blocks (BOEM, 2012).** 

**0 0.1**  **0.2 0.3**  **0.4 0.5**  **0.6 0.7**  **0.8 0.9**  **1**

**0 10 20 30 40 50 60 70 80 90 100**Power (Amp2)

Frequency (Hz) POWER SPECTRUM**Project No. 0412-2080**

**Chevron U.S.A. Inc. //**  **July 10, 2012**

**Geoscience Earth & Marine Services, Inc. ®** // 3 FORUM ENERGY TECHNOLOGIES, INC. 

### Wellsite Conditions
**The surface location is clear of any constraining geologic conditions within a 2,000-ft radius from the proposed wellsite.** 
Water Depth, Slope, and Seafloor Sediments. **Seafloor conditions are generally favorable for exploration drilling at the proposed wellsite location. The water depth at the proposed surface location is approximately**  **-7,386 ft (Map KC692-F-1). The seafloor at the proposed wells**  **ite is generally smooth, and dips to the east northeast at a fairly steep inclination of 11.3°. The ROV data confirms a relatively smooth mud bottom**  **across the proposed well location. The near-surface sediments are expected to be normally consolidated clays forming a drape over the area. The Proposed Wellsite KC 692-F is situated along the flank of a**  **broad intraslope basin named Chalmette Basin. An expansive shallow salt ridge lies approximately 2,720 ft southwest of the proposed well location. The seafloor along the salt ridge is irregular as a result of**  **numerous fault scarps, seafloor failures, and the deformation of the shallow overburden by the underlying salt (Map KC692-F-2).** 
**A shallow slope failure scarp lies approximately 2,500 ft to the west of the proposed location. Relief along the failure scar ranges from about 15 ft to 30 ft. Slopes across the scarp vary from approximately 7° to 25°.**  **Throughout the northern Gulf of Mexico continental slope region, many slope failures are covered with a surficial drape of Holocene-aged pelagic sediments (Doyle et al., 1992). This drape has accumulated since**  **the rise in sea level at the end of the Pleistocene (i.e., 12,000 yrs B.P.). The drape is ubiquitous on the continental slope. The presence of this drape over the failure scar and its debris field would indicate the**  **slump is an ancient feature thousands of years old. The lack of drape would indicate that the landslide is a relatively recent feature and slope stability is a concern for this area. The resolution of the 3-D data is not**  **adequate to define the presence or absence of the Holocene pelagic drape in this area. Therefore, the age of the seafloor failures cannot not be assessed with confidence.** 
Deepwater Benthic Communities. **There is no indication of fluids or gas venting from nearby faults at the seabed. Features or areas that could support high-density deepwater benthic communities are not located**  **within 2,000 ft of the proposed location; however, scattered deepwater corals were noted in the ROV data near the KC 692-F survey location. These small branching corals exist on soft substrate and are not**  **considered to be high-density benthic communities that are generally associated with hardgrounds. The Seafloor Amplitude Rendering (Map KC692-F-3) shows normal or ambient amplitudes along the seabed at**  **the proposed wellsite. An elevated amplitude event occurs approximately 1,800 ft southeast of the proposed location. This event likely corresponds to a change in lithology within near-surface debris flow**  **deposits and does not represent fluid/gas expulsion or carbonate hardgrounds.**
Stratigraphy. **Stratigraphic conditions are shown on Figures KC692-F-1 and KC692-F-2. The seafloor at and near-surface sediments at the Proposed Wellsite KC 692-F are expected to be hemipelagic and** **pelagic clays and silty clays. In general, the sediments between the seafloor 334 ft bml consist of clay prone run-out debris associated with the shallow slope failure approximately 2,500 ft to the west. The**  **sediments from 334 ft bml to the limit of investigation (5,299 ft bml) generally consist of hemipelagic clays and clay-rich turbidite deposits interlayered in places with thin debris flow deposits. Thin sand layers are**  **possible within the stratified turbidites and mass-transport deposits.**

Faults. **No seafloor faults are expected to be penetrated by the Proposed Wellsite KC 692-F; however, there are several faults near the proposed surface location along the shallow salt ridge to the west (Figures**  **KC692-F-1 and KC692-F-2). The closest seafloor fault to the proposed wellsite is approximately 4,300 ft to the west. The fault trends northwest-southeast and is downthrown to the east-northeast.** 
**A buried fault lies approximately 2,215 ft west of the proposed well location (Figures KC692-F-1 and KC692-F-2). This fault trends northwest-southeast and is downthrown to the northeast. No other distinct**  **faults were mapped at the Proposed Wellsite KC 692-F; however, the stratigraphic units along the salt ridge to the west are likely to be highly fractured as a result of the past motion of the underlying shallow salt**  **structure. Faults may exist at the proposed location that are beyond the resolution of the data.**

Shallow Gas and Shallow Water Flow. **Significant shallow gas is not expected at this wellsite within the upper 5,299 ft of sediment (Figures KC692-F-1 and KC692-F-2). The potential for shallow water flow at**  **this well location is considered negligible to low (Figure KC692-F-2). Project No. 0412-2080** 

**Chevron U.S.A. Inc. //**  **July 10, 2012**

**Geoscience Earth & Marine Services, Inc. ®** // 4 FORUM ENERGY TECHNOLOGIES, INC. Shallow Gas. **The potential for encountering shallow gas at the Proposed Wellsite KC 692-F ranges from negligible to low. The well path will not penetrate any high-amplitude events between the seafloor and**  **the limit of investigation (5,299 ft bml), Map KC692-F-4 and Figure KC692-F-2. Various amplitude events exist near the proposed well location at the seafloor and between the seafloor and 334 ft bml within the**  **debris flow deposits (Map KC692-F-4). An increase in amplitude character within this unit likely represents a change in lithology within the debris flow sediments. There is a low potential for encountering shallow**  **gas within this interval. A low potential for encountering shallow gas exists from Horizon 30 (2,284 ft bml) to the limit of investigation (5,299 ft bml). Low- to moderate-amplitude reflectors in places may indicate an** **increase in minor amounts of biogenic gas within possible thin sand seams within the turbidite and mass transport deposits.** 

Shallow Water Flow **. There is a negligible to low potential for shallow water flow within the sedimentary section from the seafloor to the limit of investigation (5,299 ft bml), Figure KC692-F-2. A low**  **potential for encountering overpressured sands exists within the units from Horizon 10 (999 ft bml) to the limit of investigation (5,299 ft bml). Any sands encountered within the turbidite and mass-transport deposits**  **within these units are expected to be thin seams and not likely to produce sustained flows. No nearby wells reported any shallow water flow conditions and Block KC 692 lies a significant distance downslope**  **from any recognized regional sand-bearing units. Any thin sand seams or silty-sand layers encountered are not expected to be overpressured.**  

### Closing
**The Proposed Wellsite KC 692-F in Keathley Canyon Block 692 appears suitable for exploration drilling operations. Engineers should be aware of the approximate 11.3° seafloor slope. We appreciate the**  **opportunity to be of service to Chevron on this project and look forward to working closely with you on other projects.**  **Sincerely,**

GEOSCIENCE EARTH & MARINE SERVICES, INC. ®

**Carla Cleveland Geoscientist** 

**Erin Williams Janes Daniel Lanier**  **Project Manager - Senior Geoscientist Vice President - Geoscience**

Attachments: **(4 Maps and 2 Figures) Distribution: Mr. Philip Von Dullen III, Chevron U.S.A. Inc., Houston, TX (5 Copies)** 



### References:

**Bureau of Ocean Energy Management, 2011, Notice to lessees and operators of federal oil and gas leases and pipeline right-of-way holders on the outer continental shelf, 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 OCS Region, NTL 2011-JOINT-G01.** 
**Bureau of Ocean Energy Management, 2012, ASCII data files, published on the BOEM Gulf of Mexico Region homepage, <http://www.gomr.boem.gov/homepg/pubinfo/freeasci/freedesc.html>, accessed July, 2012.** 
**Bureau of Ocean Energy Management, Regulation, and Enforcement, 2011, Pre-seabed disturbance survey mitigation, released by BOEMRE in March 2011.** 
**Coffeen, J. A., 1978, Seismic Exploration Fundamentals: Tulsa, the Petroleum Publishing Co., p. 125. Project No. 0412-2080** 

**Chevron U.S.A. Inc. //**  **July 10, 2012**

**Geoscience Earth & Marine Services, Inc. ®** // 5 FORUM ENERGY TECHNOLOGIES, INC. **Doyle, E. H., Kaluza, M. J., and H. H. Roberts, 1992, Use of manned submersibles to investigate slumps in deep water Gulf of Mexico: Proceeding of the 5**  **th International Conference of Civil Engineering in the Oceans, p. 770-782.** 
**GEMS, 2009, Geologic and stratigraphic assessment, blocks 692, 693, 735, 736, and 780, Keathley Canyon Area, Gulf of Mexico, Geoscience Earth & Marine Services, Inc.**  **® , Report No. 0109-1600.** 
**GEMS, 2012, Archaeological ROV assessment Moccasin area “F” Well, block 692, Keathley Canyon Protraction Area, U.S. Gulf of Mexico, February 2012, Geoscience Earth & Marine Services, Inc.**  **® , Report No. 0112-2040.** 
**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, Shallow hazards requirements:**  **U. S. Department of the Interior, Minerals Management Service, Gulf of Mexico, NTL 2008-G05.**
**Minerals Management Service, 2008b, 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.** 
**Minerals Management Service, 2008c, 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 Mexico, NTL 2008-G06.**
**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.**

### Chevron U.S.A. Inc. Initial Exploration Plan Keathley Canyon Block 692 Public Information (g) HIGH RESOLUTION SEISMIC LINES The high resolution seismic lines are being replaced by 3

- D seismic survey data.

(h) STRATIGRAPHIC COLUMN Proprietary Information

(i) TIME vs. DEPTH TABLE Due to adequate well control in the area, Chevron feels that a time vs. depth table is not required.

ATTACHMENTS TO SECTION C ( Proprietary Information)

**•** C- 1 - Depth Structure Contour Map

**•** C- 2, 4, 6, 8, 10 – Schematic Cross Section

**•** C- 3, 5, 7, 9, 11 – Interpreted 3 - D Seismic Line

**•** C- 12 - Stratigraphic Column

PROPRIETARY ENCLOSURE TO PLAN

**•** “ Site Clearance Letters, Proposed Wellsites KC 692 -A (KC 736 A3) , B, C, D, E, and F

, Geoscience Earth & Marine Services, Inc. ®

, July 10

, 2012 (

Project No. 0412

- 2080 ) (T wo Hard Copies and T wo Digital Copies)

### Chevron U.S.A. Inc. Initial Exploration Plan Keathley Canyon Block 692 Public Information 

## SECTION D HYDROGEN SULFIDE (H 2 

## S) INFORMATION

(a) CONCENTRATION It is not expected that H 2 

### S will be encountered or handled while conducting the activities proposed in this plan.

(b) CLASSIFICATION Pursuant to 30 CFR 250.490(c), Chevron requests the Regional Supervisor to make a determination of the area’s classification of the probability of encountering H 2 

### S during operations. No Hydrogen Sulfide has been produced or encountered in the closest well s to the area. Based on this evidence, Chevron requests that the area be classified as a zone where the absence of H 2 

### S has been confirmed.

(c) H 2 

### S CONTINGENCY PLAN Should the Regional Supervisor not classify KC Block 692 as situated in an area designated as “H 2 

### S absent” - an H 2



### S contingency plan will be proposed and submitted for approval. This proposed contingency plan would accompany the Application for Permit to Drill (APD) for the respective proposed well(s).

(d) MODELING REPORT H 2



### S concentrations greater than 500 parts per million (ppm) have not been determined or estimated to be encountered or handled while conducting the activities proposed in this plan, therefore a modeling report is not required for this plan based on the guidelines provided in NTL No. 2008

- G04.