Project No. 1106-1257b SECTION 3

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Seafloor Furrows. Dense seafloor furrows are present in the southeastern portion of the Cascade area. The 

furrows are evident in the multi-beam data as linear features trending parallel to the Escarpment (see Map 

4a). In general individual furrows average about 100 ft wide and 30 ft deep and have relatively steeply 

dipping walls. The furrows are tightly spaced, averaging between 75 and 100 ft apart. 

10 ms

~25 ft

1,000 ft

Seafloor Furrows

Seafloor Flukes

TRIPLET

10 ms

~25 ft

1,000 ft

Seafloor Furrows

Seafloor Flukes

TRIPLET

Figure 15. Subbottom profiler line 138 shows the transition between “fluked” and “furrowed” seafloor. 

The right of the figure illustrates the subbottom profiler expression of the furrows while the left side of the 

figure illustrates the flukes. The furrows incise into the otherwise undisturbed stratigraphic section. They 

are amorphous on the profiler as they act as closely-nested point sources that attenuate the profiler signal 

creating beam spreading and focusing. This is further expressed by the interference evident in the 

otherwise parallel and continuous stratigraphy below the furrows. The side-scan data show a striped 

seafloor of alternating light and dark areas illustrating the shadowing effect produced by regularly spaced, 

parallel linear furrows (see Map 7A). The soil properties are presented in Figure 16 below. 

A number of box core and short piston core samples were recovered from this region. Typically the piston 

core samples were less than 20 ft in length. Table 1 lists the cores recovered from the furrowed region of 

the UCR province. Results of the standard geotechnical testing are shown in Figure 16 with a more 

detailed presentation of results in Appendix B. 

Piston Core Box Core 

CPC-1 and CPC-1R CBOX-1 

CPC-2 and CPC-2R CBOX-2 

CPC-3 CBOX-3 

CPC-4 CBOX-4 

CPC-10 CEXP1-BOX1 

CPC-14 CEXP1-BOX2 

CPC-15 CEXP1-BOX3 

CPC-16 CEXP2-BOX1 

CEXP1-PC1 CEXP2-BOX2 

CEXP1-PC2 CEXP2-BOX3 

CEXP2-PC-1 

CEXP2-PC-2 

Table 7. List of cores for the seafloor furrows of the UCR province. 

PROPRIETARY 
Project No. 1106-1257b SECTION 3

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0 6 12345

Sensitivity

0 500 100 200 300 400

MV Shear Strength (psf)

0 2.5 0.5 1 1.5 2

Liquidity Index (LI)

0 200 40 80 120 160

Moisture Content (%)

20

0

18

16

14

12

10

8

6

4

2

Penetration below Seafloor (ft)

Figure 16. Geotechnical test results for the seafloor furrows of the UCR province 

The near surface soils within this area are generally very soft, highly plastic, normally consolidated clays. 

The soils are fairly uniform over this region of the province as is expected from soils that have been 

differentially eroded and slightly scoured due to currents. There is excellent correlation between the 

geologic observations and the ground-truth soils data. 

As can be seen in Figure 16, the moisture content data follows a decreasing trend from generally over 

120% at the seafloor to about 80% at 18 ft. The LI also decreases with depth. Shear strength was 

measured with miniature vane testing and fall within a narrow range that increases with depth. The 

strength of the surficial sediments varies between 25 and 75 psf increasing to 150 to 200 psf at 18-ft 

penetration. Soil sensitivity generally ranges between 2 and 4. Figure 16 does show occasional sensitivity 

results below 2 indicating some sample disturbance at depth. In general, the sample quality was good. 

Future facilities planned for this region of the UCR include one FPSO mooring cluster and the potential 

Gas Export Option 2 pipeline. The final selection of the pipeline route has yet to be determined and may 

never occur. The conditions in Seafloor Furrows area of the UCR are favorable for FPSO clusters and 

pipeline installation and performance. Attention should be given to the placement of the individual 

moorings with respect to the crests and troughs of the furrows. 

Seafloor Flukes. An area of seafloor flukes is observed between the Escarpment and the furrowed region. 

Individual flukes are about 150 to 200 ft in length and can be up to 10 ft in height, but more typically 

average between 5 and 8 ft high. The flukes are randomly distributed but do tend to cluster in linear to sublinear grouping perpendicular to the Escarpment and the northeasterly to southeasterly direction of current 

flow. 

The current velocity is thought to be stronger in fluked regions relative to furrowed regions. This arises 

from observations of bedforms generated in marine clays in flume tests (Allen, 1950). The increase in 

current velocity in this area may arise from a jet effect as the currents compress around a bend in the 

Escarpment to the north. The subbottom profiler data in Figure 15 shows ~ 20ft of the shallow stratigraphic 

section has been removed from this region exposing older, presumably stiffer clays at the seafloor. The 

side-scan sonar data show a mottled appearance indicating a high variability in strength or composition of 

surficial sediments. Darker areas on the side-scan mosaic (Map 7A) indicate areas where erosion has 

exposed sediments down to the level of the Triplet. 

PROPRIETARY 
Project No. 1106-1257b SECTION 3

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Several box cores and short piston core samples were recovered from the seafloor flukes area of the UCR 

province (see Table ). Typically the piston core recovery was about 15 to 18 ft in length. Results of the 

standard geotechnical testing are shown in Figure 17 with a more detailed presentation in Appendix B. 

Piston Core Box Core 

CPC-5 and CPC-5R CBOX-5 

CPC-6 CBOX-6 

CPC-7 CBOX-7 

CPC-9 CEXP1-BOX4 

CPC-10 CEXP1-BOX5 

CPC-12 CEXP1-BOX6 

CPC-13 CEXP1-BOX7 

CEXP1-PC3 CEXP1-BOX11 

CEXP1-PC4 CEXP1-BOX13 

CEXP1-PC8 CEXP1-BOX14 

CEXP1-PC9 CEXP1-BOX15 

CEXP1-BOX16 

Table 8. List of cores for seafloor flukes of the UCR province. 

0 6 12345

Sensitivity

0 500 100 200 300 400

MV Shear Strength (psf)

0 2.5 0.5 1 1.5 2

Liquidity Index (LI)

0 200 40 80 120 160

Moisture Content (%)

20

0

18

16

14

12

10

8

6

4

2

Penetration below Seafloor (ft)

Figure 17. Geotechnical test results for seafloor flukes of the UCR province. 

The soils in this area are very soft to soft, highly plastic, normally consolidated clays. The soils are fairly 

uniform over the province as is expected from soils that have been differentially eroded due to currents. 

The geotechnical data correlates well with the geologic observations from the AUV and 3D-seismic data of 

erosion and exposure of older, stronger strata. 

The moisture content and LI results tend to decrease with depth corresponding to the increasing shear 

strength. The measured shear strengths for this sub-province are very similar, but slightly higher than the 

furrowed area of the UCR. The surficial strength of the fluked sediments ranges from 25 to 100 psf and 

increases to 150 to 300 psf at 18-ft depth. Soil sensitivity ranges from 2 to 5 indicating good sample 

quality with little sample disturbance. 

Future facilities planned for this region of the UCR include the FPSO, riser bases, two mooring clusters and 

the East Drill Centers and infield flowlines. The conditions in seafloor flukes area of the UCR are 

favorable for installation and performance of these facilities. Attention should be given to the locally 

PROPRIETARY 
Project No. 1106-1257b SECTION 3

- 25 -

increased gradients on the sides of the flukes and the periodically intense seafloor currents resulting in the 

erosion and formation of the flukes. 

Seafloor Flukes and Furrows. Seafloor flukes with furrows superimposed on them are evident at the base 

of the Escarpment. This “furrowed flukes” region is more extensive along the base of the Escarpment in 

the south of the Cascade area, extending out from the Escarpment about 3.5 miles, while, to the north the 

region thins, limited to the seafloor within about 2,000 ft of the Escarpment. The furrows in this region are 

similarly formed as the furrow in the southeastern “furrowed” region; however, their appearance is quite 

different. In the multibeam data, the furrows are observed as linear features trending sub-parallel with the 

Escarpment in the south and merging with the Escarpment in the north. A hypothesis is that this is a 

transitional current velocity zone with slightly lower current velocities in the shadow of the bend in the 

Escarpment to the north. 

A combination of thrust fault related uplift, local slump deposition derived from the Escarpment, and 

seafloor erosion result in a high degree of variability in seafloor soils and shallow stratigraphy. Dark, subcircular areas seen in the side-scan data indicate slump derived debris aprons extending up to 

approximately one mile out from the Escarpment (Map 7A). Linear, dark and light striping in the side-scan 

records can represent variable soils exposed along the walls and floors of furrows; however, it may also 

represent the shadowing effect of the furrows. Thrust faulting at the toe of the Escarpment has uplifted and 

exposed older strata which, further from the Escarpment’s base, become buried in areas by slide deposits 

derived from the Escarpment. 

The soils within the Seafloor Furrowed Flukes area of the UCR province was sampled with the box corer 

and short piston corer (see Table for listing). Typically the piston core samples were less than 20 ft in 

length. Results of the standard geotechnical testing are shown in Figure 18 with a more detailed 

presentation in Appendix B. 

Piston Core Box Core 

CPC-8 CBOX-8 

CPC-11 and CPC-11R CEXP2-BOX4 

C-ESC-PC-1 

C-ESC-PC-10 and C-ESC-PC-10R 

Table 9. List of cores for the seafloor furrowed flukes region of the UCR province. 

0 6 12345

Sensitivity

0 1000 200 400 600 800

MV Shear Strength (psf)

0 2.5 0.5 1 1.5 2

Liquidity Index (LI)

0 200 40 80 120 160

Moisture Content (%)

20

0

18

16

14

12

10

8

6

4

2

Penetration below Seafloor (ft)

Figure 18. Geotechnical test results for the seafloor furrowed flukes region of the UCR province. 

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Project No. 1106-1257b SECTION 3

- 26 -

The soils in this area are very soft to soft, highly plastic, normally to slightly overconsolidated clays. The 

soils within this area, as expected, are similar to those observed in the two other areas of the UCR province, 

except where encountering a local slide deposit or exposure of stronger stratigraphy above the thrust front. 

There is excellent correlation between the geologic observations and the ground-truth soils data. 

The moisture content and LI results, presented in Figure 18, show a general decreasing trend with depth. 

The strength of the surficial sediments varies between 75 and 150 psf and increases with depth to about 

300 psf at 17 ft. Two cores (C-ESC-PC1 and E-ESC-PC10R) have a shear strength peak at ~9 ft. This is 

likely to arise from either encountering a shallow-buried debris flow or stronger soils related to uplifted 

strata above the thrust front. Soil sensitivity results are generally between 2 and 4. Figure 18 does show 

occasional sensitivity results below 2 indicating some disturbance, due either to sampling or possibly slide 

deposits. 

The West Drill Center is the only future facility planned for this region of the UCR. The geologic and 

geotechnical conditions observed appear to be favorable for placement of this facility. 

Topographic Low. A ridge, with approximately 50 ft of seabed relief, is located along the southwestern 

edge of the Cascade area (Maps 2A and 4A). The ridge represents the northern limit of a topographic low 

which extends southward out of the survey area. The low is possibly the now-filled remnant of a paleochannel that focused mass transport events coming from above, or on, the Escarpment. The flukes and 

furrows are present within the low; however, their effect on the seafloor is less pronounced than it is in the 

“furrowed” and “fluked” regions to the north. 

The subbottom profiler data, shown in Figure 19 below, shows a series of shallow anticlines in the shallow 

subsurface. Mass-transport deposits underlie the drape within synclines between the anticlines and older 

strata, down to the Triplet in places, are exposed across the crests of the anticlines at the seafloor. These 

outcrops are evident as darker areas in the side-scan mosaic (Map 7A). The anticlines likely arise from 

dewatering of the larger, deeper slide deposits and differential compaction of the overlying stratigraphic 

section. 
Project No. 1106-1257b SECTION 3

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Figure 19. The subbottom profiler data within the topographic low show folded strata in the shallow subsurface. Darker regions 

on the side-scan mosaic (Maps 1C-4C) indicate areas where the “Triplet” outcrops. 

No shallow piston core or box core samples were specifically taken in the area. However, the soils are 

expected to be consistent with those observed for the Seafloor Furrowed Flukes area of the UCR province. 

A composite of soil properties for the UCR province is presented in Figure 20 to provide a general range of 

expected properties for the Topographic Low sub-province. 

0 6 12345

Sensitivity

0 500 100 200 300 400

MV Shear Strength (psf)

0 2.5 0.5 1 1.5 2

Liquidity Index (LI)

0 200 40 80 120 160

Moisture Content (%)

20

0

18

16

14

12

10

8

6

4

2

Penetration below Seafloor (ft)

Figure 20. Composite soil information to estimate conditions for the Topographic Low region of the UCR province. 

As mentioned above mass-transport sediments underlie the drape within the synclines and the older strata 

in this area. A Jumbo Piston Coring program was recently completed that sampled this area. The JPC core 

10 ms

~25 ft

1,000 ft

TRIPLET

ANTICLINES

OUTCROPS OF THE “TRIPLET” COORESPOND TO DARKER

10 ms AREAS ON THE SIDE -SCAN MOSAIC (MAP X)

~25 ft

1,000 ft

TRIPLET

ANTICLINES

OUTCROPS OF THE “TRIPLET” COORESPOND TO DARKER

AREAS ON THE SIDE -SCAN MOSAIC (MAP 7A)

PROPRIETARY 

PROPRIETARY 
Project No. 1106-1257b SECTION 3

- 28 -

is undergoing laboratory testing. In addition to the JPC program, a soil boring and PCPT program have 

recently been completed for this area. 

Future facilities planned for this region include an FPSO mooring cluster. We believe the conditions will 

prove to be favorable for placement of the mooring. Consideration should be given to the potential for soil 

variability until the results from the additional geotechnical programs mentioned above are available. 

These additional data will subsequently be integrated to further assist in facilities layout and foundation 

engineering. 

Chemosynthetic Communities 

LCS Province. Several mound features, possible gas expulsion mounds, are identified in WR 160 as 

shown on Map 8A and in Figure 21. 

10 ms

~25 ft

1,000 ft

Expulsion Mounds

TRIPLET

Blanking

10 ms

~25 ft

1,000 ft

Expulsion Mounds

TRIPLET

Blanking

Figure 21. Subbottom profiler line 117 showing mounds in the LCS province. 

The mounds are potentially favorable locations for chemosynthetic communities to exist. The planned 

Cascade field development will not impact this area as the entire development is below the Escarpment on 

the Upper Continental Rise. Darker regions of the side-scan sonar mosaic (Map 7A) correspond with 

outcrops of the Triplet. There does not appear to be any other locations, away from the mounds, in this 

province which could support significant, high density chemosynthetic communities. The potential Gas 

Export Option 2 route is over a mile to the south-southwest from this area. 

SE Province. The Escarpment is heavily faulted and most of the faults are salt rooted. The possibility for 

migration of fluids along these faults to the seafloor exists. It is difficult to distinguish, in the side-scan 

mosaic (Map 7A) areas of potential chemosynthetic communities from outcrops of older, firmer strata as 

both will display a darker texture in the mosaic. Previous ROV studies have observed very local, small, 

dense chemosynthetic communities on the steep slopes of the Escarpment. The Cascade infield facilities 

layout does not get near the Escarpment. However, the potential Gas Export Option 2 route crosses the 

Escarpment and potential future MODU anchors are laid out to fall on the Escarpment. When necessary, to 

place subsea architecture on the Escarpment, operators in the past have selected to perform site specific 

ROV investigations to confirm the sites are clear. 

UCR Province. There does not appear to be any areas of significant, high density chemosynthetic 

communities in this province, nor areas that have conditions conducive to supporting those communities. 

Seafloor currents have, and continue to, erode and redeposit the seabed sediments throughout this province. 

PROPRIETARY 
Project No. 1106-1257b SECTION 3

- 29 -

Therefore, it is unlikely that organisms would find suitable locations with the necessary firm substrate to 

anchor themselves to the seabed. Additionally, there does not appear, in the geophysical or geotechnical 

data, to be shallow gas or active venting of fluids to the seafloor in this province. The darker regions of the 

side-scan mosaic (Map 7A) correspond to areas where the Triplet outcrops. The proposed Cascade field 

layout is entirely on the UCR and should not encounter or be constrained by chemosynthetic organisms. 
Project No. 1106-1257b SECTION 4

- 30 -

SECTION 4: SHALLOW GEOLOGIC CONDITIONS IN THE 

CHINOOK DEVELOPMENT AREA 

 Petrobras America Inc. (PAI) is evaluating development of the Chinook area in Walker Ridge Area 

(WR) in the Gulf of Mexico. PAI has proposed placing a subsea drill center in Block 425 and tie-back 

flowlines extending from the drill center to the Cascade FPSO (Section 3). The area surveyed for the 

Chinook Development area includes WR Blocks 425, 426, 469, and 470 (Map 1B). 

Bathymetry and Seafloor Gradient 

 Water depths in the Chinook Development area range from 8,607 ft in the northwestern corner of 

WR 425 to 9,260 ft in the southeastern corner of WR 470 (Map 2B). Water depths increase relatively 

uniformly across the area from northwest to southeast. An exception to this is in central WR 426 and 

northeastern WR 470 where water depths increase into a topographic low (Map 2B). 

Seafloor gradients range from nearly 0o over much of the southwestern two-thirds of the area to locally 50° 

along the walls of furrows in the northeastern third of the area (Map 3B). Seafloor gradients up to about 6° 

are common in the southeastern third of the area associated with seafloor anti-dunes. A discussion of these 

features is presented later in this section. 

Physiographic Province, Seafloor Morphology, and Stratigraphy 

 The Chinook Development area is located on the Upper Continental Rise (UCR) approximately 12 

miles south-southeast of the Sigsbee Escarpment (see Figure 3). The area exists entirely within the UCR 

province as defined in Section 3 of this report. The following three sub-provinces, as shown in Figure 22 

have been identified within the Chinook area based on the occurrence of seafloor features: (UCR) Seafloor 

Furrows; (UCR) Seafloor Anti-Dunes; and (UCR) Topographic Low. 

WR

425

WR

426

WR

469 WR

470

SEAFLOOR FURROWS

SEAFLOOR ANTI SEAFLOOR ANTI-DUNES

TOPOGRAPHIC LOW

TOPOGRAPHIC LOW

WR

425

WR

426

WR

469 WR

470

SEAFLOOR FURROWS

SEAFLOOR ANTI SEAFLOOR ANTI-DUNES

TOPOGRAPHIC LOW

TOPOGRAPHIC LOW

CHINOOK

DRILL

CENTER

CHINOOK

TiE-BACK

ROUTES

Figure 22. Physiographic sub-provinces within the Chinook Development area. 
Project No. 1106-1257b SECTION 4

- 31 -

(UCR) Seafloor Furrows. Seafloor furrows are present in the northern portion of the area (WR 425 and 

426) as shown in Figure 23 below and on Map 4B. 

10 ms

~25 ft

1,000 ft

Seafloor Furrows

TRIPLET

Figure 23. Subbottom profiler line 641 showing seafloor furrows in the Chinook area. 

The seismic stratigraphy is composed primarily of parallel and continuous reflectors. The image above 

illustrates the incisive nature of the furrows into existing parallel stratigraphy. As observed at Cascade, 

there is some attenuation and focusing of the profiler energy in the tightly spaced, very steep furrows. The 

“Triplet” is mapped in the Chinook area, Map 5B shows depths bml to the base of the transitional late 

Pleistocene (low-stand) and current Holocene (high-stand) sediments. 

The furrows are evident in the multi-beam data as linear features trending northeast to southwest (Map 4B). 

In general, individual furrows average about 100 ft wide and 30 ft deep and have relatively steeply dipping 

walls. In the northwestern corner of WR 425 the furrows are more tightly spaced, often with less than 25 ft 

between them. Further to the southeast (in the central portion of WR 425) the furrows become more spread 

out, up to 200 ft apart. These furrows also appear to branch and merge with each other. The exact nature 

of the seafloor current responsible for the varying appearance of the furrows in this area is not well 

understood at this time; however, it is possible that the dominant direction and/or intensity of the currents 

may vary over time (Maps 2B and 4B). 

The side-scan data show a striped seafloor of alternating light and dark areas (Map 6B). Soils will be 

similar to those observed in the furrowed sub-province at Cascade, varying from normally consolidated 

clays in the areas between the furrows to stiffer, slightly over-consolidated clays, silts, and possible 

foraminiferal sands along the furrow floors. 

The Chinook Tie-Back routes will cross the furrowed area as they traverse north-northeast to the Cascade 

FPSO (see Figure 22). The routes appear feasible given the observed geologic and geotechnical conditions. 

The topography of the furrows, and seafloor currents that cause them, should be considered with respect to 

the route engineering. 

(UCR) Seafloor Anti-Dunes. The remaining portions of the Chinook area, which are free of furrows, 

contain seafloor anti-dunes (Figures 24 and 25 and Map 4B). Anti-dunes are defined as low, undulating 

bedforms whose crests are in phase with the seafloor currents; therefore, they migrate by accretion in the 

upstream direction. The anti-dunes in the Chinook area are typically 2 to 5 ft in height and spaced about 

500 to 700 ft apart. They are randomly distributed, but do seem to become less prominent on the seafloor 

in the southwestern portion of the area. The side-scan data in this region displays a mottled appearance 

(Map 4B), with lighter areas indicating where anti-dunes are located. 

PROPRIETARY 
Project No. 1106-1257b SECTION 4

- 32 -

The subbottom data show parallel and continuous reflectors in the shallow stratigraphy beneath this region 

as shown in Figure 24 below. 

10 ms

~25 ft

1,000 ft

TRIPLET

Seafloor Anti-Dunes

Offset 160 ft NW

JPC-9

54.33 ft

Offset 45 ft NW

CPC-4

16.17 ft

10 ms

~25 ft

1,000 ft

TRIPLET

Seafloor Anti-Dunes

Offset 160 ft NW

JPC-9

54.33 ft

Offset 45 ft NW

CPC-4

16.17 ft

Figure 24. Subbottom profiler line 641 showing seafloor anti-dunes in the Chinook Development Area. 

A series of low anticlines exist in the southern portions of the WR 469 and 470 shown below in Figure 25. 

Figure 25. Subbottom profiler line 725 showing anticlines in WR 469 and 470. 

The folds are approximately 30 ft in height and roughly 5,000 ft between crests. These folds affect the 

seafloor and shallow stratigraphy evenly to the limit of the subbottom data. The cause of this deformation 

is not evident in the data. It is possible these features are related to compaction of large, regional masstransport deposits deeper in the stratigraphic section. 

The Chinook Drill center and southern end of the Chinook Tie-Back routes will be in this sub-province (see 

Figure 22). The geologic and geotechnical conditions are favorable for these facilities. The currents 

should be considered with respect to the development engineering. 

(UCR) Topographic Low. A topographic low with a maximum of 140 ft of seabed relief is located in the 

central portion of WR 426 (Maps 2B and 4B). This low is a continuation of the topographic low discussed 

in Section 3 of this report. Figure 26 on the next page is an annotated subbottom profiler of this subprovince. 

10 ms

~25 ft 1,000 ft

TRIPLET

10 ms

~25 ft 1,000 ft

TRIPLET

Seafloor Anti-Dune

PROPRIETARY 
Project No. 1106-1257b SECTION 4

- 33 -

10 ms

~25 ft

1,000 ft Seafloor Furrows

Seafloor Anti-Dune

within the Topographic Low

TRIPLET

10 ms

~25 ft

1,000 ft Seafloor Furrows

Seafloor Anti-Dune

within the Topographic Low

TRIPLET

Figure 26. Subbottom profiler line 720 showing the topographic low in the Chinook area. 

The figure shows a series of low folds or anticlines in the shallow subsurface. As with Cascade, the feature 

may be the shallow expression of a deeper paleo-channel that focused both regional mass-transport deposits 

and landslides emanating from the Escarpment to the north and east of the Chinook area. 

The near-surface sedimentary section (above the triplet, Map 5B) thickens, by approximately 10 to 15 ft 

within the low, possibly as a result of erosion of stratigraphy on the higher, more exposed portions of the 

stratigraphic section. The side-scan data show little variation of surficial sediments, apart from the striping 

due to furrows in the north, within this feature. Furrows are present in the northwestern portion of the low; 

however, they terminate abruptly at the edge of the low to the southwest. This suggests that the current 

regime responsible for the furrow formation may not extend down to the seafloor within this portion of the 

topographic low. Anti-dunes are present within the low; however, their effect on the seafloor is less 

pronounced than it is to the south. 

A short portion of the Chinook Tie-Back routes will cross the furrowed topographic low (see Figure 22). 

Engineering of the routes appear feasible in this area with respect to the observed geologic and 

geotechnical conditions. The seafloor currents should be considered with respect to the routes. 

Geotechnical Data 

 The Chinook area consists of a drill center that will tie-back to the Cascade FPSO via flowlines and 

umbilicals. The tie-back line traverses through the furrowed region. Three box cores were recovered from 

this area (Appendix B). The soil properties in the furrowed region are similar to those found in the 

furrowed region of the Cascade area (Section 3, Figure 13). 

Two short cores, one jumbo piston core, and one box core were recovered from the future Chinook drill 

center location (Appendix B). All the geotechnical lab data is not available at this time. Based on the 

limited box core data, the moisture contents near surface seem to follow similar profile with depth as 

observed in the Cascade area, i.e., closer to 150% at surface and reducing to 65%-100% at 12-ft depth. The 

liquidity index also follows similar trends indicating gain in strength with depth. The Chinook site consists 

of normally consolidated clays similar to those observed in the Cascade “Fluked” region (Section 3, page 

22). 

PROPRIETARY 
Project No. 1106-1257b SECTION 4

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The soil sensitivity along the tie-back route based on the limited data appears to be low. However, the 

sensitivity of soils at the drill site based on one data point appears to be low to medium. The strengths with 

depth based on all the data to date in this region are provided in the Figure 27 below. 

Piston Core Box Core 

CHPC-1 CHBOX-1 

CHPC-2 CHBOX-2 

CHPC-3 CHBOX-3 

CHPC-4 CHBOX-4 

CHBOX-5 

CHBOX-6 

CHBOX-7 

CHBOX-8 

Table 10. List of cores for the Chinook area, UCR province.

0 12 2 4 6 8 10

Sensitivity

0 500 100 200 300 400

MV Shear Strength (psf)

0 2.5 0.5 1 1.5 2

Liquidity Index (LI)

0 200 40 80 120 160

Moisture Content (%)

20

0

18

16

14

12

10

8

6

4

2

Penetration below Seafloor (ft)

Figure 27. Geotechnical test results for the Chinook area, UCR province. 

The strength of surficial material in certain areas can be expected to be as high as 200 psf. This results 

from the amount of erosion and reworking of the soils taking place within this area. The fluked region of 

the topographic low in the Cascade area shows significant erosion, down to the “Triplet” (as defined 

earlier) in many places exposing older sediments with higher strengths at the seafloor. Whereas, the 

topographic low in Chinook as mentioned earlier shows a slight thickening of surficial sediments resulting 

in slightly lower strengths in this area. 

Chemosynthetic Communities 

 Chemosynthetic Communities are not expected within the Chinook Development area. There is no 

evidence of hydrocarbon seepage to the seafloor in the geophysical data. The multibeam data reveal an 

eroded seafloor exhibiting furrows and anti-dunes. The side-scan data does not indicate areas of hard 

seabed or expulsion features. The subbottom profiler data show generally parallel and continuous 

stratigraphy.

PROPRIETARY 
Project No. 1106-1257b SECTION 5

- 35 -

SECTION 5: SEAFLOOR AND SHALLOW GEOLOGIC CONDITIONS 

 OF THE CHINOOK TIE-BACK PIPELINE CORRIDOR 

 Petrobras America Inc. (PAI) is evaluating development of the Chinook area in Walker Ridge Area 

(WR) in the Gulf of Mexico. PAI has proposed placing a drill center in Block 425 and tie-back flowlines 

extending from the drill center to the Cascade FPSO (Section 3). The area surveyed for the tie-back 

corridor includes WR Blocks 249, 293, 337, 381 and 425 (Map 1C). 

The planned pipeline corridor generally trends south to north from the Chinook drill center located in 

south-central WR 425 to the Cascade FPSO location in southeastern WR 249. Two pipelines are planned 

in the corridor. The proposed pipelines are planned as straight line runs departing the Chinook drill center 

on a north-northeast bearing and crossing WR blocks 381, 337, 293, and ending at the Cascade FPSO riser 

base PLETS located in WR 249. 

Water Depths and Gradient 

 Water Depth in the route corridor ranges from about -8,170 ft near the Cascade FPSO location in 

WR 249 to about -8,820 ft south of the Chinook drill center in WR 425 (Maps 2C and 3C). Water depths 

increase relatively uniformly southward from the Cascade FPSO location to the Chinook drill center, 

shallowing slightly in northern WR 425. 

Seabed gradients range from nearly flat to about 32° with an average along the west and east routes of 9° 

and 10°, respectively. The furrowed region of the corridor contains irregular topography with the furrows 

exhibiting high slope angles along their walls. Seabed dip angle and orientation will vary rapidly over 

short distances. The following table lists the range in water depth and average seabed gradient for the two 

routes: 

West Route 

Minimum Water Depth -8,185 ft Sta. 690+66.71 

Maximum Water Depth -8,794 ft Sta. 480+00 to 540+00

Average Seafloor Gradient 9o (15.7%) South

East Route 

Minimum Water Depth -8,190 ft Sta. 690+66.71 

Maximum Water Depth -8,794 ft Sta. 480+00 to 540+00

Average Seafloor Gradient 10o (17.5%) South

Table 11. Water depth and gradient along the Tie-Back routes.

Seafloor Currents 

 Seabed anti-dunes and furrows are present within the pipeline corridor and cannot be avoided. The 

erosional nature of these features indicates the presence of potentially strong bottom currents (possibly 

exceeding 2 knots) within the tie-back corridor. These currents may, at least in part, originate from strong 

eddies that spin off the Loop Current and “feel” bottom along the Escarpment. 

Seafloor Morphology and Soils 

 The route corridor has been divided into three soil provinces based on seafloor morphology and 

core data. The provinces are designated as Seafloor Anti-dunes, Seafloor Furrows, and Seafloor Flukes. 

Soils data from each province are provided by cores collected along the routes length. 

Seafloor Anti-dunes. Anti-dunes are defined as low, undulating bedforms whose crests are in phase with 

the seafloor currents; therefore, they migrate by accretion in the upstream direction. The anti-dunes in the 

within the corridor are typically 2 to 5 ft in height and spaced about 500 to 700 ft apart (Maps 2C and 3C). 

The side-scan sonar data in this portion of the corridor show generally light reflectivity from the Chinook 
Project No. 1106-1257b SECTION 5

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drill center to the start of the furrow field (Map 2C and 3C). This correlates with the core data (i.e., 

CHBOX-5, CHPC-1, and CHPC-4) which collected primarily very soft clay from the seabed to 17 ft bml. 

Although, CHPC-1 did collect 0.42 inches of sand at the seabed demonstrating that some variability of soils 

can be expected. 

Seafloor Furrows. Seafloor furrows are present along much of the route corridor and cannot be avoided. 

The furrows are evident in the multi-beam data as linear features trending northeast to southwest. In 

general, individual furrows average about 100 ft wide and 30 ft deep and have relatively steeply dipping 

walls. The side-scan data show a striped seafloor of alternating light and dark areas (Maps 2C and 3C). 

Soils will vary from normally consolidated clays in the areas between the furrows to stiffer, slightly overconsolidated clays, sand, and shell fragments along the furrow floors. The seafloor currents and resulting 

furrows should be considered with respect to pipeline engineering. 

Sediments 

 The surficial sediments along the proposed route will vary from silty and clayey sand to very soft 

clays, occasionally with shell fragments. Primarily soft clays are expected from the start of the routes to 

the furrows in the Chinook area. Silty sands, clayey sands, sandy clays, and clays mixed with shell 

fragments are expected along the route where furrows are present. North of the furrowed area to the end of 

the route in WR 293, the surficial sediments are composed of very soft clays over sandy clay grading to 

very soft clay westward. 

Two short cores, one jumbo piston core, and one box core were recovered from the future Chinook drill 

center location (Appendix B). All the geotechnical lab data is not available at this time. Based on the 

limited box core data, the moisture contents near surface seem to follow similar profile with depth as 

observed in the Cascade area, i.e. closer to 150% at surface and reducing to 65%-100% at 12 ft depth. The 

liquidity index also follows similar trends indicating gain in strength with depth (Section 4, Figure 27). 

The strength of surficial material in certain areas can be expected to be as high as 200 psf. This results 

from the amount of erosion and reworking of the soils taking place within this area. 

The near surface soils within this area are mainly very soft to soft high plastic clays becoming firm to stiff 

with depth (Appendix B). The strengths near surface are in the range of 15-50 PSF with maximum at some 

locations reaching up to 100 psf, a few inches below the surface (Section 3, Figure 16). Interestingly, the 

CBOX-2 indicates strengths greater than 150 psf. It is believed that this sample is possibly sandy. A thin 

drape of foraminiferal clayey-sand is commonly observed in furrowed areas. Ripple marks, indicative of a 

sandy seabed, have been observed in other furrowed regions below the Escarpment. The moisture content 

varies between 150% near surface decreasing to 100% around 5-ft depth. The liquidity index near surface 

is in excess of two and drops to one at depth. The sensitivity data indicates low sensitivity over the entire 

site. The soils appear favorable for installation and operation of the flowlines. 

Man-made Features and Conditions 

 There are no man-made features or conditions that are considered to be a constraint to pipeline 

installation and operation. The proposed routes will not cross any shipping safety fairways, ordnance or 

waste disposal sites, or military areas. No shipwrecks are reported within the survey corridor or along the 

proposed route. No other man-made features or conditions occur along the proposed route that would 

hinder or constrain pipe-lay activities or operation. 

GEOLOGIC CONDITIONS ALONG THE PROPOSED WEST FLOWLINE ROUTE 

 The proposed West Gas Flowline begins at a PLET (pipeline end termination) structure north of the 

Chinook drill center (start-of-line, Sta.00+00) and continues in a straight line segment to a PLET near the 

south riser base at the Cascade FPSO location (end-of-line, Sta. 611+81.01), Map 2C. From Sta. 00+00 to 

Sta. 37+45 the route traverses seafloor anti-dunes in the Chinook development area. Seafloor furrows are 
Project No. 1106-1257b SECTION 5

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present from Sta. 37+45.96 to Sta. 538+29.16. North of Sta. 538+29.16 to the end of the route the seafloor 

contains flukes. 

The following tables outline the coordinates for the beginning, termination point, and block crossings as 

well as water depth and seafloor gradient along the West Flowline route. 

Proposed 9 5/8-Inch Gas Pipeline West Route Description 

Designation 

Points 

X Coordinate 

(ft) 

Y Coordinate 

(ft) 

Latitude 

(degrees North) 

Longitude 

(degrees West) 

Station 

Number 

Start of Pipeline 2,446,912.87’ 9,633,069.91’ 26° 31’ 34.55” 90° 31’ 59.20” 00+00.00 

Block Crossing 

WR 425/381 2,448,319.95’ 9,646,560.00’ 26° 33’ 47.81” 90° 31’ 40.86” 135+63.28 

Block Crossing 

WR 381/337 2,449,972.15’ 9,662,400.00’ 26° 36’ 24.29” 90° 31’ 19.29” 294+89.21 

Block Crossing 

WR 337/293 2,451,624.34’ 9,678,240.00’ 26° 39’ 00.77” 90° 30’ 57.71” 454+15.14 

End of Pipeline 2,453,259.93’ 9,693,920.80’ 26° 41’ 35.67” 90° 30’ 36.32” 611+81.01 

Table 12. West Tie-Back block crossings.

Minimum Water 

Depth 

Maximum Water 

Depth 

Average Water 

Depth 

Maximum 

Seafloor 

Gradient 

Average Seafloor 

Gradient 

-8,185 ft -8,794 ft 32.7o / 57.1% 

STA. 690+66.71 Sta. 480+00 to 

540+00 

-8,530 ft 

STA. 184+35 

9o / 15.7% 

Table 13. Water depth and gradient along the west Tie-Back route.

Man-made Features and Conditions 

 The proposed West Flowline will not cross any existing pipelines or wellsites. The locations of 

side-scan sonar targets relative to the proposed route are show on Maps 1C. The sonar targets are small 

contacts with little or no relief and are believed to be unknown man-made debris. The nearest sonar target 

is Target No. 24, located 316 ft east of the flowline route at Sta. 385+36.86 (Map 2C, Sheet 2). The preinstallation ROV survey should be able to identify this potential debris and ascertain whether removal is 

required. 

Chemosynthetic Communities 

 Chemosynthetic communities are not expected along the West Flowline route. There is no 

evidence of hydrocarbon seepage to the seafloor in the geophysical data. The occurrence of periodic strong 

bottom currents in this area have scoured and eroded the seafloor. The multibeam data reveal an eroded 

seafloor exhibiting furrows, anti-dunes, and flukes. The side-scan data does not indicate areas of hard 

seabed or expulsion features. 

GEOLOGIC CONDITIONS ALONG THE PROPOSED EAST FLOWLINE ROUTE 

 The proposed East Gas Flowline begins at a PLET (pipeline end termination) structure north of the 

Chinook drill center (start-of-line, Sta.00+00) and continues in a straight line segment to a PLET near the 

south riser base at the Cascade FPSO location (end-of-line, Sta. 610+61.81). From Sta. 00+00 to Sta. 

38+88.70 the route traverses seafloor anti-dunes in the Chinook development area. Seafloor furrows are 

present from Sta. 38+88.70 to Sta. to Sta. 544+88.34. North of Sta. 544+88.34 to the end of the route the 

seafloor contains flukes. 
Project No. 1106-1257b SECTION 5

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The following tables outlines the coordinates for the beginning, termination point, and block crossings as 

well as water depth and seafloor gradient along the East Flowline route. 

Proposed 9 5/8-Inch Gas Pipeline East Route Description 

Designation 

Points 

X Coordinate 

(ft) 

Y Coordinate 

(ft) 

Latitude 

(degrees North) 

Longitude 

(degrees West) 

Station 

Number 

Start of Flowline 2,447,145.93’ 9,633,044.60’ 26° 31’ 34.25” 90° 31’ 56.64” 00+00.00 

Block Crossing 

WR 425/381 2,448,586.97’ 9,646,560.00’ 26° 33’ 47.76” 90° 31’ 37.92” 135+92.01 

Block Crossing 

WR 381/337 2,450,275.86’ 9,662,400.00’ 26° 36’ 24.23” 90° 31’ 15.95” 295+21.79 

Block Crossing 

WR 337/293 2,451,964.76’ 9,678,240.00’ 26° 39’ 00.70” 90° 30’ 53.96” 454+51.57 

End of Pipeline 2,453,619.77’ 9,693,762.26’ 26° 41’ 34.03” 90° 30’ 32.39” 610+61.81 

Table 14. West Tie-Back block crossings.

Minimum Water 

Depth 

Maximum Water 

Depth 

Average Water 

Depth 

Maximum 

Seafloor 

Gradient 

Average Slope 

-8,190 ft -8,794 ft 32.0o / 55.9% 

STA. 690+66.71 Sta. 480+00 to 

540+00 

-8,531 ft 

STA. 510+00 

9o / 15.7% 

Table 15. Water depth and gradient along the east Tie-Back route.

Man-made Features and Conditions

 The proposed East Flowline will not cross any existing pipelines or wellsites. The locations of 

side-scan sonar targets relative to the proposed route are show on Maps 1C. The sonar targets are small 

contacts with little or no relief. The nearest sonar target is Target No. 24, located 6.8 ft west of the flowline 

route at Sta. 385+37.94 (Map 3C, Sheet 2). The pre-installation ROV survey should be able to identify this 

potential debris and ascertain whether removal is required. 

Chemosynthetic Communities 

 Chemosynthetic communities are not expected along the East Flowline route. There is no evidence 

of hydrocarbon seepage to the seafloor in the geophysical data. The occurrence of periodic strong bottom 

currents in this area have scoured and eroded the seafloor. The multibeam data reveal an eroded seafloor 

exhibiting furrows, anti-dunes, and flukes. The side-scan data does not indicate areas of hard seabed or 

expulsion features. 
Project No. 1106-1257b SECTION 6

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SECTION 6: FINDINGS AND RECOMMENDATIONS 

The Cascade and Chinook development has a planned FPSO facility to be emplaced in the southeast corner 

of WR 249, drill centers in WR 205, 249, and 425, a tie-back pipeline between the drill center in WR 425 

and the FPSO, and various infield flowlines and umbilicals. The proposed Cascade, Chinook, and Chinook 

Tie-Back flowlines appear feasible for development. 

GEMS conducted an integrated geologic and geotechnical study for the Cascade and Chinook Prospects. 

GEMS coordinated a geophysical survey conducted by C&C Technologies, Inc., using their AUV system 

to acquire multibeam swath bathymetry, sidescan sonar, and subbottom profiler data. An extensive 

geotechnical program has also been conducted. All data were used to assess the site conditions for the 

planned drilling and production activities. 

Cascade Development Area 

The Cascade area displays a variety of seafloor and geologic features resulting from past salt-related 

structural deformation as well as past and present seafloor erosion. The most prominent feature is the 

Sigsbee Escarpment, which crosses the northwestern part of the area. The Escarpment itself has variable 

gradients and thickness of sedimentary cover overlying older, very stiff to hard soils. Faulting in many 

places along the Escarpment results in a rough topography, has uplifted and exposed older strata, and 

contributed to numerous past failures. 

In the area of the development itself, below the Escarpment on the Upper Continental Rise, seafloor 

currents have significantly eroded the seabed below the Escarpment resulting in extensive furrows and 

flukes on the seafloor. The furrows average about 100 ft wide and 30 ft deep and have relatively steeply 

dipping walls and are tightly spaced, averaging between 75 and 100 ft apart. The flukes are about 150 to 

200 ft in length and can be up to 10 ft in height, but more typically average between 5 and 8 ft high. 

The following findings are made based on examination of available data for the Cascade area: 

1. The water depth in the Cascade area varies from 5,637 ft to 8,510 ft and seafloor gradients range 

from nearly 0o to approximately 70° along the steeper portions of the Sigsbee Escarpment. 

2. The area consists of three geomorphologic provinces, the Lower Continental Slope, the Sigsbee 

Escarpment, and the Upper Continental Rise with the Escarpment crossing the northwestern 

portion of the area. 

3. The Escarpment displays high slope angles and rugged topography. 

4. Seafloor furrows and flukes are present over most of the proposed Cascade, Chinook, and Chinook 

Tie-Back proposed facilities areas. 

5. Periodic strong seabed currents are responsible for the formation of the furrows and flukes. 

6. Several gas expulsion mounds are observed on the Lower Continental Slope in the northeast 

portion of WR 160, but these are over a mile from any possible future architecture (Export Option 

2) and far from the main development below the Escarpment. 

7. The shallow stratigraphy over the area consists generally of parallel-bedded, differentially eroded 

hemipelagic clays resulting in varying soil properties at the seabed. Sands and coarse lag deposits 

may exist in the bottom of the furrows and be distributed throughout the area. 

8. Slump deposits from the Escarpment form debris aprons that extend ~1.0 mile from the base of the 

Escarpment. The nearest proposed facility is 0.5 mile from the most distal apron. 

9. There are no geologic constraints such as active faulting, gas venting, or hard bottom conditions 

that would impact field development. The potential for encountering chemosynthetic communities 

is remote. 
Project No. 1106-1257b SECTION 6

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10. .With the exception of the existing exploration wellsites, there are no other man-made structures 

reported in the Cascade area. 

Chinook Development Area 

The Chinook Development appears feasible based on the observed geologic and geotechnical data. The 

following findings are made based on examination of available data for the Chinook area: 

1. Water depths in the Chinook Development area range from 8,607 ft 9,260 ft and seafloor gradients 

range from nearly 0o to about 50° along the walls of furrows. 

2. The shallow stratigraphy over the area consists generally of parallel-bedded, differentially eroded 

hemipelagic clays. Sands are present along the floors of the furrows. 

3. The Chinook area displays active erosional seafloor features consisting of furrows and anti-dunes. 

4. Periodic strong seabed currents are responsible for the formation of the furrows and anti-dunes. 

5. The furrows are located in the northern portion of the area and the anti-dunes are present in the 

south and west. 

6. The furrows are similar in size and spacing as those identified in the Cascade area. 

7. The anti-dunes are typically 2 to 5 ft in height and spaced about 500 to 700 ft apart. 

8. The proposed Drill Center lies in the anti-dune area. 

9. The proposed Chinook Tie-Back routes begin at the Drill Center in the anti-dune area and will 

encounter the furrows as they traverse north-northeast to the Cascade FPSO. 

10. There are no geologic constraints such as active faulting, gas venting, or hard bottom conditions 

that would impact field development. The potential for encountering chemosynthetic communities 

is remote. 

11. With the exception of the existing exploration wellsites, there are no other man-made structures 

reported in the Cascade area. 

Chinook Tie-Back Corridor 

The Tie-Back corridor traverses the seafloor between the Chinook Drill Center and the proposed Cascade 

FPSO location. The seafloor within the corridor is furrowed over much of its length. Seafloor flukes exist 

at the northern end of the corridor, near the FPSO location, and anti-dunes are present at the Chinook Drill 

Center in the south. 

The following findings are made based on examination of available data for the Chinook area: 

1. There are two proposed gas tie-back pipelines and one production umbilical in the corridor. 

2. Water depths in the corridor range from -8,820 ft to -8,170 ft and seabed gradients in the corridor range 

from nearly 0o to locally approaching 32°, with an average along the west and east routes of 9° and 10°, 

respectively. 

3. The shallow stratigraphy beneath the corridor consists generally of parallel-bedded, differentially 

eroded hemipelagic clays. Sands are present along the floors of the furrows. 

4. Periodic strong seabed currents are responsible for the formation of the furrows and anti-dunes. 

5. Irregular seafloor consisting of anti-dunes, furrows, and flukes are present at various locations along 

the entire length of the corridor. 

6. Sonar Contact No. 24 lies 6.8 feet from the proposed East Gas Pipeline Route at about Sta. 385+37.94. 

This target, which has no measurable height, is 4-ft wide, and 10-ft long, and may be modern debris. 

No other sonar contacts lie directly along the proposed pipeline or umbilical routes. 
Project No. 1106-1257b SECTION 6

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7. There are no geologic constraints such as active faulting, gas venting, or hard bottom conditions that 

would impact pipeline lay operations. The potential for encountering chemosynthetic communities is 

remote. 

Summary of Geologic and Geotechnical Findings With Respect to Proposed Field 

Architecture 

The table beginning on the next page provides a summary of the geologic processes and geotechnical 

conditions for each of the physiographic provinces defined in sections 3, 4, and 5 of this report and 

describes which proposed facilities will fall into these conditions. 
Project No. 1106-1257b 

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Table 16. SUMMARY TABLE: 

Physiographic 

Region Geologic Conditions Geotechnical Properties Comments Planned Infrastructure 

LOWER CONTINENTAL SLOPE

1) The shallow stratigraphy, to 

approximately 260 ft below the mud-line consists of well layered to amorphous reflectors. 

2) The base of this surficial unit 

is identified as the “Triplet”. 

3) Carbon-14 dating of the three 

distinct silt-rich layers indicate that the layers were deposited between ~18.9 – 20.2 ka (1ka=1000 yrs) slightly before the end of the last low stand, i.e., Pleistocene/Holocene boundary. 

1) Soils in these areas are 

generally high plastic, clays with a low sensitivity. 

2) The soils are fairly 

uniform over the areal extent and are normally to slightly overconsolidated. 

3) The moisture content 

near surface is in excess of 100% and it reduces to approximately 70% at 20 ft depth. 

4) Shear strength increases 

linearly with depth. The strength of the surficial sediments varies between 40 psf and 70 psf. At some locations strengths in surficial sediments have been measured up to 150 psf.

1) The Triplet is an important 

marker horizon in the area because it both marks the base of the transitional late Pleistocene (low-stand) and current Holocene (high-stand) sediments. Both of these are present above and below the Sigsbee Escarpment. 

2) Faults are present, caused by 

the underlying salt movement, and have resulted in the uplift and erosion of the sediments above the triplet in various portions of the area. Below the Triplet the stratigraphy can be characterized by parallel continuous layers. 

3) Occasionally, strengths in 

surficial sediments can be expected to be as high as 150 psf. 

The potential Gas Export Optiroute is the only planned infrastructure in this region. Tgeologic and geotechnical conditions are favorable for piinstallation and operation. 

SIGSBEE ECARPMENT 

Upper Scarp 

1) The upper scarp is rugged, 

faulted, and steeply dipping. 

2) Faults are salt rooted, trend 

parallel to the Escarpment face, and are typically downthrown to the southwest. Throw across the faults is highly variable, but is as much as 20 ft. 

3) Thin to absent drape, or 

outcropping strata characterize the upper and lower scarps. 

1) The moisture content of 

near surface sediments is in excess of 100% but drops rapidly 50% within few inches. 

2) The shear strengths vary 

based on sampling of the normally consolidated drape or the much stiffer, overconsolidated underlying strata. 

1) The currents are exposing the 

stiffer layers due to erosion. 

The potential Gas Export Optioroute will traverse the Upper ScSpans and flowline stability shobe considered with respect to engineering. Future additionalspecific studies may be pertinewith respect to topography, soistability, and chemosynthetic communities. 
Project No. 1106-1257b 

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Physiographic 

Region Geologic Conditions Geotechnical Properties Comments Planned Infrastructure 

Bench 

1) The bench is widest and 

smoothest in WR 205 and thins and becomes more rugged to the north and south. 

2) A possible drop in current 

velocity allows for the deposition and ponding and preservation of sediments, of varying thicknesses, over the bench. 

1) The strength of these 

sediments is lower than the ones observed in both the Upper and Lower scarps. This material is underlain by stiffer material, probably the continuation of the sequences observed in the Upper and Lower Scarps. 

2) The shear strengths vary 

based on sampling of the normally consolidated drape or the much stiffer, overconsolidated underlying strata. 

1) The Bench is the transition 

between the Upper Scarp and Lower Scarp. 

The potential Gas Export Optioroute will traverse the Bench. and flowline stability should be considered with respect to engineering. Future additionalspecific studies may be pertinewith respect to topography, soistability, and chemosynthetic communities. 

Lower Scarp 

1) Numerous slumps and gullies 

incise the lower scarp with debris aprons extending up to approximately 1 mile out onto the Upper Continental Rise. 

1) The liquidity index of 

surficial layer is slightly less than 0.5 

2) The shear strengths vary 

based on sampling of the normally consolidated drape or the much stiffer, overconsolidated underlying strata. The strength of this underlying strata is observed to be stronger than that of the Upper Scarp and Bench. 

1) Furrows are present on the 

Escarpment and indicate seabed currents are actively eroding and re-depositing the surficial sediments. 

2) Seafloor expression of a 

thrust wedge is evident at the base of the Lower Scarp. 

The potential Gas Export Optiroute will traverse the Lower SSpans and flowline stability shbe considered with respect to engineering. Future additionaspecific studies may be pertinewith respect to topography, sostability, and chemosynthetic communities. 
Project No. 1106-1257b 

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Physiographic 

Region Geologic Conditions Geotechnical Properties Comments Planned Infrastructure 

Furrows & Flukes 

1) This region is more extensive 

in the south, extending out from the Escarpment about 3.5 miles, while to the north the region thins, limited to the seafloor within about 2,000 ft of the Escarpment. 

2) A combination of thrust fault 

related uplift, slump deposition derived from the Escarpment and current erosion result in a high degree of variability in shallow seafloor soils. 

1) The near surface 

moisture content in this region is approximately 100% reducing to 60% at depth. 

2) The soils are normally 

to slightly over consolidated. 

3) The liquidity index has 

a value of 1.5 near surface and drops below one at twelve feet depth. 

1) The area is between the 

Escarpment and “Fluke” region to the south. This forms the part of the “Upper Continental Rise”. 

2) The soils within this entire 

region are generally uniform with subtle differences in their geotechnical properties. 

The SW Cascade drill center ainfield flowlines and umbilicalassociated with the SW drill ceare located in this province. 

The geologic and geotechnical conditions are favorable for shafoundations. 

The seafloor currents should bconsidered in this area. The topography of the furrows flukes should be considered wrespect to placement of the individual field architecture. 

UPPER CONTINENTAL RISE 

Flukes 

1) Flukes are about 150 to 200 ft 

in length and can be up to 10 ft in height, but more typically average between 5 and 8 ft high. 

2) Seafloor currents are thought 

to be stronger in fluked regions. 

1) High plastic normally to 

slightly overconsolidated clays at depth. 

2) Moisture content in 

excess 0f 100% near surface decreasing close to 30% at 500 ft depth. 

3) Soils near surface 

slightly stiffer than “Furrowed” area. 

1) The side-scan sonar data show 

a mottled appearance indicating a high variability in surficial sediments. 

2) Seafloor currents have eroded 

surficial layer and exposed stiffer material near surface in some areas. Strengths closer to 400 psf can be expected in those areas. 

3) Based on the current data, the 

strength estimates determined using overall strength relationship with the exception of lower bound strength, are expected to be within + 25% of the location 

specific data. 

Infrastructure located within thprovince include: the riser basthe FPSO, the north and southwFPSO mooring clusters, infield flowlines and umbilicals, and tChinook tie-back pipeline. 

The geologic and geotechnical conditions are favorable for shafoundations. 

The seafloor currents should bconsidered in this area. The topography of the flukes sbe considered with respect to placement of the individual fiearchitecture.. 
Project No. 1106-1257b 

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Physiographic 

Region Geologic Conditions Geotechnical Properties Comments Planned Infrastructure 

Furrows 

1) In general individual furrows 

average about 100 ft wide and 30 ft deep and have relatively steeply dipping walls. 

2) The furrows are tightly 

spaced, averaging between 75 and 100 ft apart. 

1) The soils are normally 

to slightly overconsolidated 

2) The moisture content of 

150% near surface decreasing to 100% around 5ft depth. 

3) L.I. >2 near surface and 

decreasing to one at depth. 

4) The sensitivity data 

indicates low sensitivity. 

1) Along the furrow floors 

strengths near surface can be expected to be in excess of 100 psf. 

2) Foraminifera sand may cover 

the furrow floors as well as be randomly distributed over the area. This sand is mobile, being eroded and reworked by periodic active seafloor currents.

The FPSO southeast mooring cis located within this province. The geologic and geotechnical conditions are favorable for shafoundations. The topography of the furrows should be considered with respplacement of the individual moorings. 

The seafloor currents should bconsidered in this area. 

Topographic Low 

1) The low is possibly the 

remnant of a filled channel or results from landslides emanating from the Escarpment to the south and east of the Cascade area. 

2) The flukes and furrows 

continue into the low; however, their effect on the seafloor is less pronounced. 

 1) The soils are normally 

to slightly overconsolidated. 

1) Soils in this area are generally 

stronger than the soils observed in “Flukes” area. 

2) The strength estimates 

determined using overall strength relationship with the exception of lower bound strength, are expected to be 20-30% lower than those determined using location specific data. 

The southwest FPSO mooring cluster and the Chinook tie-bacpipeline are located within the topographic low. The results of this study should integrated with the in-process dgeotechnical investigation resuaddress foundation design for tFPSO moorings at Cascade. The topography of the furrows this area at Chinook should be considered in the pipeline desigThe seafloor currents should be considered in this area. 

UPPER CONTINENTAL RISE

Seafloor Anti-Dunes 

1)The anti-dunes are typically 2 

to 5 ft in height and spaced about 500 to 700 ft apart. 

2)The anti-dunes are randomly 

distributed, but become less prominent to the southwest. 

1) Normally consolidated 

clays similar to the “fluked” province. 

2) The moisture content of 

150% near surface decreasing to 65%-100% at 12ft depth. 

3) The sensitivity data 

indicates low sensitivity. 

The Chinook drill center and thback pipeline are located in thiprovince. The geologic and geotechnical conditions are favorable for shafoundations. 

The seafloor currents should bconsidered in this area. 
Project No. 1106-1257b SECTION 6

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Recommendations 

The observations of the geologic and geotechnical conditions in the Cascade, Chinook, and Chinook TieBack Corridor appear feasible for development. We provide the following recommendations based on the 

observed conditions and our previous experience on deepwater projects below the Sigsbee Escarpment: 

1. Consider the local seabed topography in the furrows, flukes, and furrow/flukes soil provinces at 

Cascade with respect to the placement of individual pieces of seafloor and shallow-founded field 

architecture such as FPSO moorings, PLETS, PLEMS, manifolds, pumps, and riser bases. 

2. Consider the topography in the furrows, flukes, and furrow/flukes soil provinces at Cascade with 

respect to the design of infield, tie-back, and gas export flowlines. 

3. Consider the periodically strong currents that have caused the erosion over this broad region with 

respect to scour and overall facilities engineering. 

4. Conduct current monitoring studies to fully establish the range of velocities of these currents near 

the seabed. 

5. If Export Option 2 is selected, consider more site-specific, detailed studies with respect to the local 

topography, soil conditions, slope stability, and potential presence of chemosynthetic communities 

on the Sigsbee Escarpment crossing. 

6. Conduct a future slope stability assessment for the Sigsbee Escarpment to assess the slope 

conditions with respect to the location of the proposed facilities at Cascade. 

7. Consider the topography through the furrowed regions with respect to detailed design of the 

Chinook Tie-Back flowlines upon completion of the planned higher-resolution bathymetric survey 

along the Chinook Tie-Back corridor. 

8. Integrate the results of the Jumbo Piston Core and Rotary Soil Borings and PCPT geotechnical 

investigations with the existing geophysical and shallow geotechnical data to assist in engineering 

design of the various seabed and shallow foundations. 

If the facilities layouts for the various developments are modified, this report can be used as a basis to 

assess the geologic and very shallow geotechnical site conditions with respect to the new layout(s). 

Petrobras America, Inc. 

Development Operations Coordination Document 

Cascade / Chinook Development Project 

APPENDIX 3 

Air Emissions Worksheets 
This page left blank intentionally. 
DOCD AIR QUALITY SCREENING CHECKLIST 

OMB Appro

COMPANY Petrobras America, Inc.AREA Walker RidgeBLOCK 206 *LEASE OCS-G 16965 *PLATFORM FPSOWELL Cascade Wells No. 6 and 7COMPANY CONTACT Gregory D. RolandTELEPHONE NO. (713) 808-2495REMARKSLEASE TERM PIPELINE CONSTRUCTION INFORMATION:

YEAR NUMBER OF TOTAL NUMBER OF CONSTRUCTION DAYS

PIPELINES

2012 02013 02014 02015 02016 0

* Workbook details construction and production for the following areas : Walker Ridge Block 206, Lease OCS-G 16965 Walker Ridge Block 249, Lease OCS-G 16969 --> Location of FPSO (used for distance in exemption calc Walker Ridge Block 425, Lease OCS-G 16987

Form MMS-139 (August 2003)Page 1 of 8
AIR EMISSION CUMPUTATION FACTORS

Fuel Usage Conversion Factors Natural Gas Turbines Natural Gas Engines Diesel Recip. Engine REF. DA

SCF/hp-hr 9.524 SCF/hp-hr 7.143 GAL/hp-hr 0.0483 AP42 3.2-1 4/76 

Drillship GAL/hp-hr 0.0061 Actual fuel burn - Email - Petrobras -USA 2/2Workboat (12,400 Hp) GAL/hp-hr 0.0100 Actual fuel burn - Email - Petrobras -USA 2/2Crewboat GAL/hp-hr 0.0125 Actual fuel burn - Email - Petrobras -USA 2/2Sea-going Tug GAL/hp-hr 0.0145 Actual fuel burn - Email - Petrobras -USA 2/2Diesel Generator - Essential & EG GAL/hp-hr 0.0478 Actual fuel burn - Email - Petrobras -USA 2/2Main Engine (Sulzer) GAL/hp-hr 0.0366 Actual fuel burn - Email - Petrobras -USA 2/2Diesel fire water pump (Fischcon) GAL/hp-hr 0.0511 Actual fuel burn - Email - Petrobras -USA 2/2Turbine Solar Titan 130 SCF/hp-hr 9.339 Actual fuel burn - Email - Petrobras -USA 2/2Equipment/Emission Factors units PM SOx NOx VOC CO REF. DANG Turbines gms/hp-hr 0.00247 1.3 0.01 0.83 AP42 3.2-1& 3.1-1 10NG 2-cycle lean gms/hp-hr 0.00185 10.9 0.43 1.5 AP42 3.2-1 10NG 4-cycle lean gms/hp-hr 0.00185 11.8 0.72 1.6 AP42 3.2-1 10NG 4-cycle rich gms/hp-hr 0.00185 10 0.14 8.6 AP42 3.2-1 10Diesel Recip. < 600 hp. gms/hp-hr 1 1.468 14 1.12 3.03 AP42 3.3-1 10Diesel Recip. > 600 hp. gms/hp-hr 0.32 1.468 11 0.33 2.4 AP42 3.4-1 10Diesel Recip. > 600 hp. gms/hp-hr 8.1 MARPOL 73/78* 3/Crude Fired Recip. < 600 hp. gms/hp-hr 1 9.909 14 1.12 3.03 AP42 3.3-1 10Crude Fired Recip. > 600 hp. gms/hp-hr 0.32 9.909 11 0.33 2.4 AP42 3.4-1 10Diesel Boiler lbs/bbl 0.084 2.42 0.84 0.008 0.21 AP42 1.3-12,14 9/HFO Boiler lbs/bbl 0.42 16.335 2.31 0.012 0.21 AP42 1.3-12,14 9/NG Heaters/Boilers/Burners lbs/mmscf 7.6 0.593 100 5.5 84 AP42 1.4-1, 14-2, & 14-3 7/NG Flares lbs/mmscf 0.593 71.4 60.3 388.5 AP42 11.5-1 9Liquid Flaring lbs/bbl 0.42 6.83 2 0.01 0.21 AP42 1.3-1 & 1.3-3 9/Tank Vapors lbs/bbl 0.06 AP42 5.2 7/Fugitives lbs/hr/comp. 0.0005 API Study 12Glycol Dehydrator Vent lbs/mmscf 6.6 La. DEQ 19Gas Venting lbs/scf 0.0034Helicopter - Sikorsky H-60 Class lbs/hr 3.13 0.30 5.28 0.41 3.10 AESO Memo 6/Agusta Westland AW-139 lbs/hr 0.22 0.30 7.80 3.02 3.68 FOCA 3/2

Sulfur Content Source Value Units

Fuel Gas 3.33 ppm

Diesel Fuel 0.4 % weight

HFO / Crude Oil 2.7 % weight

Produced Gas( Flares) 3.33 ppm

Produced Oil (Liquid Flaring) 1 % weight

1.) "Deep Ocean Mendocino" MODU emissions based on manufacturer's guarantee meeting regulation 13 of ANNEX VI of MARPOL 73/78 - 45 x (engine rpm

2.) "Dragon Quest" MODU emissions based on manufacturer's guarantee meeting regulation 13 of ANNEX VI of MARPOL 73/78 - 45 x (engine rpm)-0.2 g/kW4.) AW-139 Emissions: Swiss Confederation, Guidance on the Determination of Helicopter Emissions, Federal Department of the Environment, Transport, EnerFederal Office of Civil Aviation FOCA Division Aviation Policy and Strategy Edition 1 - March 2009. No SO2 emisisons are provide. Therefore, the emissions for 

3.) FPSO and Shuttle tank emissions are calculated using the vapor pressure curves(vapor pressure vs temperature) for each type of crude (AP42, Chptr 5). In available for a given crude, the vapor curve for Arabian Light is used by Petrobras for international operations (anything produced outside of Brazil). The US EPassociated with Crude RVP5. Therefore, the emissions listed under Crude (RVP 5) should be considered as most representative of the FPSO operations. 

Form MMS-139 (August 2003)Page 2 of 8
AIR EMISSIONS CALCULATIONS - 2012

COMPANY AREA BLOCK LEASE PLATFORM WELL CONTACT PHONE REMARKS

Petrobras America, Inc. Walker Ridge 206 OCS-G 16965 FPSO Cascade Wells No. 6 and 7 Gregory D. Roland (713) 808-2495 0

OPERATIONS EQUIPMENT RATING MAX. FUEL ACT. FUEL RUN TIME MAXIMUM POUNDS PER HOUR 

Diesel Engines HP GAL/HR GAL/D

Nat. Gas Engines HP SCF/HR SCF/D

Burners MMBTU/HR SCF/HR SCF/D HR/D DAYS PM SOx NOx VOC CO PM 

PRODUCTION FPSO - RECIP.> 600hp (1 Solar Titan 130 Total hp) standby 0 0 0 0 0 0 0 0 0 0 

FPSO - TURBINES Natural Gas (2 Solar Titan 130 Total hp - 57%) 22,167 207,020 4,968,487 24 365 0.12 63.47 0.49 40.53 

FPSO - RECIP.>600hp diesel Main (Sulzer) 100% 11,828 433.2 10397.59 24 13.1 8.34 38.24 286.58 8.60 62.53 1.3FPSO - RECIP.>600hp diesel (2 Cummins QSK60-D(M) 1 100% /1 backup) Gen 2548 121.8 2922.65 24 12.5 1.80 8.24 61.73 1.85 13.47 0.26FPSO - RECIP.>600hp diesel (Cummins QSK60-D(M)) EG 1274 60.9 1461.33 1 26 0.90 4.12 30.87 0.93 6.73 0.0

FPSO - BURNER diesel (2 Dual Fuel Pyro Steam Boilers 1 standby - 60%)) 21.5 24 365 0.38 14.62 2.07 0.01 0.19 1.6FPSO - RECIP.>600hp diesel (Fischcon Fire Pump - 50%) 701 35.8 859.31 1 26 1.54 2.27 21.61 1.73 4.68 0.0FPSO - IGG System burner (A & B) 32 24 52 0.57 22.05 3.12 0.02 0.28 0.3Shuttle Vessel - RECIP.>600hp diesel (Loading from FPSO) 3264 157.7 3783.6 24 52 2.30 10.55 79.08 2.37 17.25 1.4Shuttle Vessel - RECIP.>600hp diesel (Transit within 25 miles) 11424 551.8 13242.7 24 20 8.05 36.94 276.79 8.30 60.39 1.9

Shuttle Vessel - RECIP.>600hp diesel (Loading from FPSO) 3264 157.7 3783.6 24 52 2.30 10.55 79.08 2.37 17.25 1.4Shuttle Vessel - RECIP.>600hp diesel (Transit within 25 miles) 11424 551.8 13242.7 24 20 8.05 36.94 276.79 8.30 60.39 1.9VESSELS >600hp Diesel (PSV Workboat 12400 hp, used at 60%) 12400 124.2 2980 20 108 8.74 40.10 300.44 9.01 65.55 9.4

VESSELS >600hp Diesel (PSV Workboat 12400 hp, used at 60%) 12400 124.2 2980 20 108 8.74 40.10 300.44 9.01 65.55 9.4

VESSELS >600hp Diesel (PSV Workboat 12400 hp, used at 60%) 12400 124.2 2980 20 108 8.74 40.10 300.44 9.01 65.55 9.4

VESSELS >600hp diesel (FSV Crew Boat) 4120 51.67 1240 11 156 2.90 13.32 99.82 2.99 21.78 2 VESSELS >600hp diesel (FSV Crew Boat) 4120 51.67 1240 11 156 2.90 13.32 99.82 2.99 21.78 2 VESSELS >600hp diesel (Sea-going Tug) 5784 84.00 2016 24 365 4.08 18.70 140.14 4.20 30.58 18 

DRILLING PRIME MOVER>600hp diesel (Drill Rig - 20%) Deep Ocean Mendocino 12840 394.0 9456 24 365 9.05 41.52 229.08 9.33 67.88 39.6

PRIME MOVER>600hp diesel (Drill Rig - 20%) Dragon Quest 12840 394.0 9456 24 365 9.05 41.52 229.08 9.33 67.88 39.6MISC. BPD SCF/HR COUNTFPSO - TANK (Vapors @ Production Rate) 72,000 24 365 178.93 Shuttle tanker Loading - 50% IG 330,000 24 52 410.06 

FLARE- (upset considered insignificant) 0 0 0 0.00 0.00 0.00 0.00 

PROCESS VENT 0 0 0 0.00 FUGITIVES- 11420.0 365 5.71 

GLYCOL STILL VENT- 0.1471 24 365 9.71E-07 

AW-139 Helicopter (Production Operations) 3060 139 3336.0 3 365 0.22 0.60 15.61 6.04 7.36 0.1

DRILLING OIL BURN 0 0 0 0.00 0.00 0.00 0.00 0.00 0 WELL TEST GAS FLARE 0 0 0 0.00 0.00 0.00 0.00 

2012 YEAR TOTAL 88.65 433.91 2896.08 691.61 697.60 140.

EXEMPTION 

CALCULATION DISTANCE FROM LAND IN MILES 5494

165.0

Notes:1.) The air emissions worksheet only captures Shuttle Vessel air emissions while the Shuttle Vessel is within 25 miles of the FPSO. 2.) Offloading from FPSO (20%), transit within 25 miles of FPSO (80%). Based on 1 Shuttle Vessel offloading every week.
AIR EMISSIONS CALCULATIONS - 2013

COMPANY AREA BLOCK LEASE PLATFORM WELL CONTACT PHONE REMARKS

Petrobras America, Inc. Walker Ridge 206 OCS-G 16965 FPSO Cascade Wells No. 6 and 7 Gregory D. Roland (713) 808-2495 0

OPERATIONS EQUIPMENT RATING MAX. FUEL ACT. FUEL RUN TIME MAXIMUM POUNDS PER HOUR 

Diesel Engines HP GAL/HR GAL/D

Nat. Gas Engines HP SCF/HR SCF/D

Burners MMBTU/HR SCF/HR SCF/D HR/D DAYS PM SOx NOx VOC CO PM 

PRODUCTION FPSO - RECIP.> 600hp (1 Solar Titan 130 Total hp) standby 0 0 0 0 0 0 0 0 0 0 

FPSO - TURBINES Natural Gas (2 Solar Titan 130 Total hp - 57%) 22,167 207,020 4,968,487 24 365 0.12 63.47 0.49 40.53 

FPSO - RECIP.>600hp diesel Main (Sulzer) 100% 11,828 433.2 10397.59 24 13.1 8.34 38.24 286.58 8.60 62.53 1.31

FPSO - RECIP.>600hp diesel (2 Cummins QSK60-D(M) 1 100% /1 backup) Gen 2548 121.8 2922.65 24 12.5 1.80 8.24 61.73 1.85 13.47 0.26

FPSO - RECIP.>600hp diesel (Cummins QSK60-D(M)) EG 1274 60.9 1461.33 1 26 0.90 4.12 30.87 0.93 6.73 0.01

FPSO - BURNER diesel (2 Dual Fuel Pyro Steam Boilers 1 standby - 60%)) 21.5 24 365 0.38 14.62 2.07 0.01 0.19 1.65 

FPSO - RECIP.>600hp diesel (Fischcon Fire Pump - 50%) 701 35.8 859.31 1 26 1.54 2.27 21.61 1.73 4.68 0.02 

FPSO - IGG System burner (A & B) 32 24 52 0.57 22.05 3.12 0.02 0.28 0.35 

Shuttle Vessel - RECIP.>600hp diesel (Loading from FPSO) 3264 157.7 3783.6 24 52 2.30 10.55 79.08 2.37 17.25 1.44 

Shuttle Vessel - RECIP.>600hp diesel (Transit within 25 miles) 11424 551.8 13242.7 24 20 8.05 36.94 276.79 8.30 60.39 1.93 Shuttle Vessel - RECIP.>600hp diesel (Loading from FPSO) 3264 157.7 3783.6 24 52 2.30 10.55 79.08 2.37 17.25 1.44 Shuttle Vessel - RECIP.>600hp diesel (Transit within 25 miles) 11424 551.8 13242.7 24 20 8.05 36.94 276.79 8.30 60.39 1.93 VESSELS >600hp Diesel (PSV Workboat 12400 hp, used at 60%) 12400 124.2 2980 20 108 8.74 40.10 300.44 9.01 65.55 9.44 VESSELS >600hp Diesel (PSV Workboat 12400 hp, used at 60%) 12400 124.2 2980 20 108 8.74 40.10 300.44 9.01 65.55 9.44 VESSELS >600hp Diesel (PSV Workboat 12400 hp, used at 60%) 12400 124.2 2980 20 108 8.74 40.10 300.44 9.01 65.55 9.44 VESSELS >600hp diesel (FSV Crew Boat) 4120 51.67 1240 11 156 2.90 13.32 99.82 2.99 21.78 2 VESSELS >600hp diesel (FSV Crew Boat) 4120 51.67 1240 11 156 2.90 13.32 99.82 2.99 21.78 2 VESSELS >600hp diesel (Sea-going Tug) 5784 84.00 2016 24 365 4.08 18.70 140.14 4.20 30.58 18 

DRILLING PRIME MOVER>600hp diesel (Drill Rig - 20%) Deep Ocean Mendocino 12840 394.0 9456 24 365 9.05 41.52 229.08 9.33 67.88 39.6

PRIME MOVER>600hp diesel (Drill Rig - 20%) Dragon Quest 12840 394.0 9456 24 365 9.05 41.52 229.08 9.33 67.88 39.6

MISC. BPD SCF/HR COUNTFPSO - TANK (Vapors @ Production Rate) 80,000 24 365 198.82 Shuttle tanker Loading - 50% IG 330,000 24 52 410.06 FLARE- (upset considered insignificant) 0 0 0 0.00 0.00 0.00 0.00 PROCESS VENT 0 0 0 0.00 FUGITIVES- 11420.0 365 5.71 

GLYCOL STILL VENT- 0.1471 24 365 9.71E-07 AW-139 Helicopter (Production Operations) 3060 139 3336.0 3 365 0.22 0.60 15.61 6.04 7.36 0.12 

DRILLING OIL BURN 0 0 0 0.00 0.00 0.00 0.00 0.00 0 WELL TEST GAS FLARE 0 0 0 0.00 0.00 0.00 0.00 

2013 YEAR TOTAL 88.65 433.91 2896.08 711.50 697.60 140.9

EXEMPTION 

CALCULATION DISTANCE FROM LAND IN MILES 5494

165.0

Notes:1.) The air emissions worksheet only captures Shuttle Vessel air emissions while the Shuttle Vessel is within 25 miles of the FPSO. 2.) Offloading from FPSO (20%), transit within 25 miles of FPSO (80%). Based on 1 Shuttle Vessel offloading every week.
AIR EMISSIONS CALCULATIONS - 2014

COMPANY AREA BLOCK LEASE PLATFORM WELL CONTACT PHONE REMARKS

Petrobras America, Inc. Walker Ridge 206 OCS-G 16965 FPSO Cascade Wells No. 6 and 7 Gregory D. Roland (713) 808-2495 0

OPERATIONS EQUIPMENT RATING MAX. FUEL ACT. FUEL RUN TIME MAXIMUM POUNDS PER HOUR 

Diesel Engines HP GAL/HR GAL/D

Nat. Gas Engines HP SCF/HR SCF/D

Burners MMBTU/HR SCF/HR SCF/D HR/D DAYS PM SOx NOx VOC CO PM 

PRODUCTION FPSO - RECIP.> 600hp (1 Solar Titan 130 Total hp) standby 0 0 0 0 0 0 0 0 0 0 

FPSO - TURBINES Natural Gas (2 Solar Titan 130 Total hp - 57%) 22,167 207,020 4,968,487 24 365 0.12 63.47 0.49 40.53 

FPSO - RECIP.>600hp diesel Main (Sulzer) 100% 11,828 433.2 10397.59 24 13.1 8.34 38.24 286.58 8.60 62.53 1.31

FPSO - RECIP.>600hp diesel (2 Cummins QSK60-D(M) 1 100% /1 backup) Gen 2548 121.8 2922.65 24 12.5 1.80 8.24 61.73 1.85 13.47 0.26

FPSO - RECIP.>600hp diesel (Cummins QSK60-D(M)) EG 1274 60.9 1461.33 1 26 0.90 4.12 30.87 0.93 6.73 0.01

FPSO - BURNER diesel (2 Dual Fuel Pyro Steam Boilers 1 standby - 60%)) 21.5 24 365 0.38 14.62 2.07 0.01 0.19 1.65 

FPSO - RECIP.>600hp diesel (Fischcon Fire Pump - 50%) 701 35.8 859.31 1 26 1.54 2.27 21.61 1.73 4.68 0.02 

FPSO - IGG System burner (A & B) 32 24 52 0.57 22.05 3.12 0.02 0.28 0.35 

Shuttle Vessel - RECIP.>600hp diesel (Loading from FPSO) 3264 157.7 3783.6 24 52 2.30 10.55 79.08 2.37 17.25 1.44 

Shuttle Vessel - RECIP.>600hp diesel (Transit within 25 miles) 11424 551.8 13242.7 24 20 8.05 36.94 276.79 8.30 60.39 1.93 

Shuttle Vessel - RECIP.>600hp diesel (Loading from FPSO) 3264 157.7 3783.6 24 52 2.30 10.55 79.08 2.37 17.25 1.44 Shuttle Vessel - RECIP.>600hp diesel (Transit within 25 miles) 11424 551.8 13242.7 24 20 8.05 36.94 276.79 8.30 60.39 1.93 

VESSELS >600hp Diesel (PSV Workboat 12400 hp, used at 60%) 12400 124.2 2980 20 108 8.74 40.10 300.44 9.01 65.55 9.44 VESSELS >600hp Diesel (PSV Workboat 12400 hp, used at 60%) 12400 124.2 2980 20 108 8.74 40.10 300.44 9.01 65.55 9.44 VESSELS >600hp Diesel (PSV Workboat 12400 hp, used at 60%) 12400 124.2 2980 20 108 8.74 40.10 300.44 9.01 65.55 9.44 VESSELS >600hp diesel (FSV Crew Boat) 4120 51.67 1240 11 156 2.90 13.32 99.82 2.99 21.78 2 VESSELS >600hp diesel (FSV Crew Boat) 4120 51.67 1240 11 156 2.90 13.32 99.82 2.99 21.78 2 

DRILLING PRIME MOVER>600hp diesel (Drill Rig - 20%) Deep Ocean Mendocino 12840 394.0 9456 24 365 9.05 41.52 229.08 9.33 67.88 39.6

PRIME MOVER>600hp diesel (Drill Rig - 20%) Dragon Quest 12840 394.0 9456 24 365 9.05 41.52 229.08 9.33 67.88 39.6

VESSELS >600hp diesel (Sea-going Tug) 5784 84.00 2016 24 365 4.08 18.70 140.14 4.20 30.58 18 

MISC. BPD SCF/HR COUNTFPSO - TANK (Vapors @ Production Rate) 80,000 24 365 198.82 

Shuttle tanker Loading - 50% IG 330,000 24 52 410.06 

FLARE- (upset considered insignificant) 0 0 0 0.00 0.00 0.00 0.00 PROCESS VENT 0 0 0 0.00 FUGITIVES- 11420.0 365 5.71 GLYCOL STILL VENT- 0.1471 24 365 9.71E-07 AW-139 Helicopter (Production Operations) 3060 139 3336.0 3 365 0.22 0.60 15.61 6.04 7.36 0.12 

DRILLING OIL BURN 0 0 0 0.00 0.00 0.00 0.00 0.00 0 WELL TEST GAS FLARE 0 0 0 0.00 0.00 0.00 0.00 

2014 YEAR TOTAL 88.65 433.91 2896.08 711.50 697.60 140.9

EXEMPTION 

CALCULATION DISTANCE FROM LAND IN MILES 5494

165.0

Notes:1.) The air emissions worksheet only captures Shuttle Vessel air emissions while the Shuttle Vessel is within 25 miles of the FPSO. 2.) Offloading from FPSO (20%), transit within 25 miles of FPSO (70%). Based on 1 Shuttle Vessel offloading every week.
AIR EMISSIONS CALCULATIONS - 2015

COMPANY AREA BLOCK LEASE PLATFORM WELL CONTACT PHONE REMARKS

Petrobras America, Inc. Walker Ridge 206 OCS-G 16965 FPSO Cascade Wells No. 6 and 7 Gregory D. Roland (713) 808-2495 0

OPERATIONS EQUIPMENT RATING MAX. FUEL ACT. FUEL RUN TIME MAXIMUM POUNDS PER HOUR 

Diesel Engines HP GAL/HR GAL/D

Nat. Gas Engines HP SCF/HR SCF/D

Burners MMBTU/HR SCF/HR SCF/D HR/D DAYS PM SOx NOx VOC CO P

PRODUCTION FPSO - RECIP.> 600hp (1 Solar Titan 130 Total hp) standby 0 0 0 0 0 0 0 0 0 0 

FPSO - TURBINES Natural Gas (2 Solar Titan 130 Total hp - 57%) 22,167 207,020 4,968,487 24 365 0.12 63.47 0.49 40.53 

FPSO - RECIP.>600hp diesel Main (Sulzer) 100% 11,828 433.2 10397.59 24 13.1 8.34 38.24 286.58 8.60 62.53 1.3

FPSO - RECIP.>600hp diesel (2 Cummins QSK60-D(M) 1 100% /1 backup) Gen 2548 121.8 2922.65 24 12.5 1.80 8.24 61.73 1.85 13.47 0.2FPSO - RECIP.>600hp diesel (Cummins QSK60-D(M)) EG 1274 60.9 1461.33 1 26 0.90 4.12 30.87 0.93 6.73 0.0FPSO - BURNER diesel (2 Dual Fuel Pyro Steam Boilers 1 standby - 60%)) 21.5 24 365 0.38 14.62 2.07 0.01 0.19 1.6FPSO - RECIP.>600hp diesel (Fischcon Fire Pump - 50%) 701 35.8 859.31 1 26 1.54 2.27 21.61 1.73 4.68 0.0FPSO - IGG System burner (A & B) 32 24 52 0.57 22.05 3.12 0.02 0.28 0.3Shuttle Vessel - RECIP.>600hp diesel (Loading from FPSO) 3264 157.7 3783.6 24 52 2.30 10.55 79.08 2.37 17.25 1.4Shuttle Vessel - RECIP.>600hp diesel (Transit within 25 miles) 11424 551.8 13242.7 24 20 8.05 36.94 276.79 8.30 60.39 1.9

Shuttle Vessel - RECIP.>600hp diesel (Loading from FPSO) 3264 157.7 3783.6 24 52 2.30 10.55 79.08 2.37 17.25 1.4

Shuttle Vessel - RECIP.>600hp diesel (Transit within 25 miles) 11424 551.8 13242.7 24 20 8.05 36.94 276.79 8.30 60.39 1.9

VESSELS >600hp Diesel (PSV Workboat 12400 hp, used at 60%) 12400 124.2 2980 20 108 8.74 40.10 300.44 9.01 65.55 9.4VESSELS >600hp Diesel (PSV Workboat 12400 hp, used at 60%) 12400 124.2 2980 20 108 8.74 40.10 300.44 9.01 65.55 9.4VESSELS >600hp Diesel (PSV Workboat 12400 hp, used at 60%) 12400 124.2 2980 20 108 8.74 40.10 300.44 9.01 65.55 9.4VESSELS >600hp diesel (FSV Crew Boat) 4120 51.67 1240 11 156 2.90 13.32 99.82 2.99 21.78 2 VESSELS >600hp diesel (FSV Crew Boat) 4120 51.67 1240 11 156 2.90 13.32 99.82 2.99 21.78 2 VESSELS >600hp diesel (Sea-going Tug) 5784 84.00 2016 24 365 4.08 18.70 140.14 4.20 30.58 1

DRILLING PRIME MOVER>600hp diesel (Drill Rig - 20%) Deep Ocean Mendocino 12840 394.0 9456 24 365 9.05 41.52 229.08 9.33 67.88 39.

PRIME MOVER>600hp diesel (Drill Rig - 20%) Dragon Quest 12840 394.0 9456 24 365 9.05 41.52 229.08 9.33 67.88 39.MISC. BPD SCF/HR COUNTFPSO - TANK (Vapors @ Production Rate) 80,000 24 365 198.82 

Shuttle tanker Loading - 50% IG 330,000 24 52 410.06 

FLARE- (upset considered insignificant) 0 0 0 0.00 0.00 0.00 0.00 PROCESS VENT 0 0 0 0.00 FUGITIVES- 11420.0 365 5.71 GLYCOL STILL VENT- 0.1471 24 365 9.71E-07 

AW-139 Helicopter (Production Operations) 3060 139 3336.0 3 365 0.22 0.60 15.61 6.04 7.36 0.

DRILLING OIL BURN 0 0 0 0.00 0.00 0.00 0.00 0.00 0 WELL TEST GAS FLARE 0 0 0 0.00 0.00 0.00 0.00 

2015 YEAR TOTAL 88.65 433.91 2896.08 711.50 697.60 140

EXEMPTION 

CALCULATION DISTANCE FROM LAND IN MILES 5494

165.0

Notes:1.) The air emissions worksheet only captures Shuttle Vessel air emissions while the Shuttle Vessel is within 25 miles of the FPSO. 2.) Offloading from FPSO (20%), transit within 25 miles of FPSO (70%). Based on 1 Shuttle Vessel offloading every week.
AIR EMISSIONS CALCULATIONS - 2016

COMPANY AREA BLOCK LEASE PLATFORM WELL CONTACT PHONE REMARKS

Petrobras America, Inc.Walker Ridge 206 OCS-G 16965 FPSO Cascade Wells No. 6 and 7 Gregory D. Roland (713) 808-2495 0

OPERATIONS EQUIPMENT RATING MAX. FUEL ACT. FUEL RUN TIME MAXIMUM POUNDS PER HOUR 

Diesel Engines HP GAL/HR GAL/D

Nat. Gas Engines HP SCF/HR SCF/D

Burners MMBTU/HR SCF/HR SCF/D HR/D DAYS PM SOx NOx VOC CO PM 

PRODUCTION FPSO - RECIP.> 600hp (1 Solar Titan 130 Total hp) standby 0 0 0 0 0 0 0 0 0 

FPSO - TURBINES Natural Gas (2 Solar Titan 130 Total hp - 57%) 22,167 207,017 4,968,405 24 365 0.12 63.47 0.49 40.53 

FPSO - RECIP.>600hp diesel Main (Sulzer) 100% 11,828 433.2 10397.59 24 13.1 8.34 38.24 286.58 8.60 62.53 1.311 FPSO - RECIP.>600hp diesel (2 Cummins QSK60-D(M) 1 100% /1 backup) Gen 2548 121.8 2922.65 24 12.5 1.80 8.24 61.73 1.85 13.47 0.269 FPSO - RECIP.>600hp diesel (Cummins QSK60-D(M)) EG 1274 60.9 1461.33 1 26 0.90 4.12 30.87 0.93 6.73 0.012 FPSO - BURNER diesel (2 Dual Fuel Pyro Steam Boilers 1 standby - 60%)) 21.5 24 365 0.38 14.62 2.07 0.01 0.19 1.65 FPSO - RECIP.>600hp diesel (Fischcon Fire Pump - 50%) 701 35.8 859.31 1 26 0.49 2.27 16.98 0.51 3.70 0.01 FPSO - IGG System burner (A & B) 32 24 52 0.57 22.05 3.12 0.02 0.28 0.35 Shuttle Vessel - RECIP.>600hp diesel (Loading from FPSO) 3264 157.7 3783.6 24 52 2.30 10.55 79.08 2.37 17.25 1.44 

Shuttle Vessel - RECIP.>600hp diesel (Transit within 25 miles) 11424 551.8 13242.7 24 20 8.05 36.94 276.79 8.30 60.39 1.93 Shuttle Vessel - RECIP.>600hp diesel (Loading from FPSO) 3264 157.7 3783.6 24 52 2.30 10.55 79.08 2.37 17.25 1.44 Shuttle Vessel - RECIP.>600hp diesel (Transit within 25 miles) 11424 551.8 13242.7 24 20 8.05 36.94 276.79 8.30 60.39 1.93 VESSELS >600hp Diesel (PSV Workboat 12400 hp, used at 60%) 12400 124.2 2980 20 108 8.74 40.10 300.44 9.01 65.55 9.44 

VESSELS >600hp Diesel (PSV Workboat 12400 hp, used at 60%) 12400 124.2 2980 20 108 8.74 40.10 300.44 9.01 65.55 9.44 VESSELS >600hp Diesel (PSV Workboat 12400 hp, used at 60%) 12400 124.2 2980 20 108 8.74 40.10 300.44 9.01 65.55 9.44 VESSELS >600hp diesel (FSV Crew Boat) 4120 51.67 1240 11 156 2.90 13.32 99.82 2.99 21.78 2 VESSELS >600hp diesel (FSV Crew Boat) 4120 51.67 1240 11 156 2.90 13.32 99.82 2.99 21.78 2 VESSELS >600hp diesel (Sea-going Tug) 5784 84.00 2016 24 365 4.08 18.70 140.14 4.20 30.58 18 

DRILLING PRIME MOVER>600hp diesel (Drill Rig - 20%) Deep Ocean Mendocino 12840 394.0 9456 24 365 9.05 41.52 229.08 9.33 67.88 39.64 

PRIME MOVER>600hp diesel (Drill Rig - 20%) Dragon Quest 12840 394.0 9456 24 365 9.05 41.52 229.08 9.33 67.88 39.64 MISC. BPD SCF/HR COUNTFPSO - TANK (Vapors @ Production Rate) 48,000 24 365 119.29 

Shuttle tanker Loading - 50% IG 330,000 24 52 410.06 

FLARE- (upset considered insignificant) 0 0 0 0.00 0.00 0.00 0.00 

PROCESS VENT 0 0 0 0.00 

FUGITIVES- 11420.0 365 5.71 

GLYCOL STILL VENT- 0.1471 24 365 9.71E-07 AW-139 Helicopter (Production Operations) 3060 139 3336.0 3 365 0.22 0.60 15.61 6.04 7.36 0.12 

DRILLING OIL BURN 0 0 0 0.00 0.00 0.00 0.00 0.00 0 

WELL TEST GAS FLARE 0 0 0 0.00 0.00 0.00 0.00 

2016 YEAR TOTAL 87.60 433.91 2891.45 630.75 696.63 140.8

EXEMPTION 

CALCULATION DISTANCE FROM LAND IN MILES 5494.5

165.0

Notes:1.) The air emissions worksheet only captures Shuttle Vessel air emissions while the Shuttle Vessel is within 25 miles of the FPSO. 

2.) Offloading from FPSO (20%), transit within 25 miles of FPSO (80%). Based on 1 Shuttle Vessel offloading every week.
AIR EMISSION CALCULATIONS OM

OMB Approval E

COMPANY AREA BLOCK LEASE PLATFORM WELLPetrobras America, Inc. Walker Ridge 206 OCS-G 16965 FPSO Cascade Wells N

Emitted Substance

Year

 PM SOx NOx VOC C

2012 140.91 715.26 4349.43 499.44 1222013 140.91 715.26 4349.43 521.34 1222014 140.91 715.26 4349.43 521.34 1222015 140.91 715.26 4349.43 521.34 1222016 140.89 715.26 4349.36 433.72 122

Allowable 5494.50 5494.50 5494.50 5494.50 1022

* Workbook details construction and production for the following areas : Walker Ridge Block 206, Lease OCS-G 16965 Walker Ridge Block 249, Lease OCS-G 16969 --> Location of FPSO (used for distance in exemption ca Walker Ridge Block 425, Lease OCS-G 16987
Petrobras America, Inc. 

Development Operations Coordination Document 

Cascade / Chinook Development Project 

APPENDIX 4

 Oil Spill Response Equipment

 Response Times 
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WCD Scenario– BASED ON WELL BLOWOUT DURING DRILLING OPERATIONS (165 miles from s

18,135 bbls of crude oil API Gravity 23° 

APPENDIX 4 – Equipment Response Time to WR 206 

Dispersants/Surveillance 

Dispersant/Surveillance Dispersant Capacity (gal) Storage Capacity Persons Req. From Hrs to Procure Hrs to Loadout Travel to sit

CGA

Basler 67T 2000 NA 2 Houma 1 1 1.0 

ASI 

DC 3 1200 NA 2 Houma 1 1 1.3 DC 3 1200 NA 2 Houma 1 1 1.3 Aero Commander NA NA 2 Houma 1 1 1.0 

Offshore Response 

Offshore Equipment No 

Staging EDRC Storage Capacity VOO Persons Required From Hrs to Procure Hrs to Loadout Hrs to GOM 

CGA

HOSS Barge 43000 4000 3 Tugs 8 Harvey 7 0 5 

Recovered Oil Storage No 

Staging EDRC Storage Capacity VOO Persons Required From Hrs to Procure Hrs to Loadout Hrs to GOM 

Enterprise Marine Services LLC (available through contract with CGA) 

CTCo 2605 NA 20000 1 Tug 6 Amelia 4 12 4 CTCo 5001 NA 47000 1 Tug 6 Amelia 4 12 4 
Staging Area: Venice 

Offshore Equipment With 

Staging EDRC Storage Capacity VOO Persons Req. From Hrs to Procure Hrs to Loadout Travel to Staging 

CGA

FRU (1) + 100 bbl Tank (2) 3770 200 1 Utility 6 Belle Chasse 1 2 2 FRU (3) + 100 bbl Tank (5) 11310 500 1 Utility 6 Houma 1 2 3 FRU (1) + 100 bbl Tank (2) 3770 200 1 Utility 6 Lake Charles 1 2 5.5 FRU (2) + 100 bbl Tank (4) 7540 400 1 Utility 6 Venice 1 2 0 42” Auto Boom (5000’) NA NA 10 Crew 20 Belle Chasse 1 2 2 42” Auto Boom (5000’) NA NA 10 Crew 20 Galveston 1 2 8 42” Auto Boom (5000’) NA NA 10 Crew 20 Houma 1 2 3 42” Auto Boom (2500’) NA NA 6 Crew 12 Ingleside 1 2 11 42” Auto Boom (5000’) NA NA 10 Crew 20 Lake Charles 1 2 5.5 42” Auto Boom (2500’) NA NA 6 Crew 12 Pascagoula 1 2 4 1000’ Hydro-Fire Boom NA NA 8 Utility 40 Harvey 1 4 2 
Nearshore Response 

Nearshore Equipment 

No Staging EDRC Storage Capacity VOO Persons Required From Hrs to Procure Hrs to Loadout Hrs to GOM Trav

Spill 

CGA 

46’ FRV 5000 65 NA 4 Venice 1 0 1 2.

Enterprise Marine Services LLC (available through CGA contract) 

CTCo 2606 NA 20000 1 Tug 6 Amelia 4 12 4 1

Staging Area: Venice 

Nearshore and Inland 

Skimmers With Staging EDRC Storage Capacity VOO Persons Req. From Hrs to Procure Hrs to Loadout Travel to Staging Tr

Dep

CGA

SWS Egmopol 3000 100 NA 3 Galveston 1 2 8 SWS Egmopol 3000 100 NA 3 Houma 1 2 3 SWS Marco 3588 34 NA 3 Houma 1 2 3 SWS Marco 3588 20 NA 3 Lake Charles 1 2 5.5 Rope Mop 77 2 0 3 Belle Chasse 1 2 2 RO Storage Barge NA 249 Towed 0 Galveston 1 2 8 RO Storage Barge NA 249 Towed 0 Houma 1 2 3 RO Storage Barge NA 249 Towed 0 Lake Charles 1 2 5.5 RO Storage Barge NA 249 Towed 0 Venice 1 2 0 
Shoreline Protection 

18” Shoreline Protection 

Boom VOO Persons Req. Storage/Warehouse Location Hrs to Procure Hrs to Loadout Travel to Staging Travel to Deployment Site 

Staging Area: Cameron

USES (available through Letter of Intent) 

6000’ 18” Boom 5 Crew 14 Meraux, LA .5 .5 4.75 2 5000’ 18” Boom 3 Crew 8 Mobile, AL .5 .5 6 2 1000’ 18” Boom 1 Crew 3 Geismar, LA .5 .5 3.5 2 4500’ 18” Boom 3 Crew 8 Houston, TX .5 .5 2.5 2 4000’ 18” Boom 2 Crew 6 Venice, LA .5 .5 6.25 2 2000’ 18” Boom 1 Crew 3 Jackson, MS .5 .5 5.75 2 2000’ 18” Boom 1 Crew 3 Southaven, MS .5 .5 8.75 2 1000’ 18” Boom 1 Crew 3 Nashville, TN .5 .5 12.25 2 1500’ 18” Boom 1 Crew 3 Birmingham, AL .5 .5 9.25 2 1000’ 18” Boom 1 Crew 3 Biloxi, MS .5 .5 5.5 2 

Staging Area: Galveston

Miller (available through Letter of Intent) 

14,000’ 18” Boom 6 Crew 12 Sulphur, LA .5 1 2.75 2 14,000’ 18” Boom 6 Crew 12 Beaumont, TX .5 1 2 2 60,000’ 18” Boom 10 Crew 20 Corpus Christi, TX .5 2 4.25 2 

Staging Area: Venice

AMPOL (available through Letter of Intent) 

42,000’ 18” Boom 16 Crew 40 New Iberia, LA 2 2 4 2 20,000’ 18” Boom 8 Crew 20 New Orleans, LA 2 2 2 2 

Oil Mop (available through Letter of Intent) 

10,000’ 18” Boom 4 Crew 10 New Iberia, LA 1 1 4 2 10,000’ 18” Boom 4 Crew 10 Houston, TX 1 1 7.5 2 10,000’ 18” Boom 4 Crew 10 Port Arthur, TX 1 1 6.25 2 20,000’ 18” Boom 8 Crew 20 Belle Chasse, LA 1 1 1.75 2 10,000’ 18” Boom 4 Crew 10 Port Allen, LA 1 1 3.5 2 10,000’ 18” Boom 4 Crew 10 Houma, LA 1 1 3.5 2 15,000’ 18” Boom 6 Crew 14 Gretna, LA (Warehouse) 2 2 2 2 
Staging Area: Venice 

Beach Boom EDRC Storage Capacity VOO Persons Req. From Hrs to Procure Hrs to Loadout Travel to Staging Tr

Dep

CGA

Beach Boom (2000’) NA NA NA 6 Galveston 1 2 8 Beach Boom (1000’) NA NA NA 4 Ingleside 1 2 11 Beach Boom (2000’) NA NA NA 6 Pascagoula 1 2 4 

Wildlife Response EDRC Storage Capacity VOO Persons Req. From Hrs to Procure Hrs to Loadout Travel to Staging Tr

Dep

CGA 

Wildlife Support Trailer NA NA NA 2 Houma 1 2 3 Bird Scare Guns (24) NA NA NA 2 Belle Chasse 1 2 2 Bird Scare Guns (12) NA NA NA 2 Galveston 1 2 8 Bird Scare Guns (24) NA NA NA 2 Houma 1 2 3 Bird Scare Guns (12) NA NA NA 2 Ingleside 1 2 11 Bird Scare Guns (24) NA NA NA 2 Lake Charles 1 2 5.5 Bird Scare Guns (24) NA NA NA 2 Pascagoula 1 2 4 

Response Asset Total 

Offshore EDRC 69,390 Offshore Recovered Oil Storage 72,300 Nearshore / Shallow Water EDRC 18,253 Nearshore / Shallow Water Recovered Oil Storage 21,317 
Petrobras America, Inc. 

Development Operations Coordination Document 

Cascade / Chinook Development Project 

APPENDIX 5 

Oil Spill Risk Analysis (OSRA) Report 
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Petrobras America, Inc. 

Development Operations Coordination Document 

Cascade / Chinook Development Project 

APPENDIX 6 

Worst-Case Discharge Evaluation
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