In Reply Refer To: MS 5231 January 14, 1991

Office of

Oryx Energy Company Attention: Mr. A. B. Norwood Poat Of f i ce Box 1501 Houston, Texas 77251-1501

Program Services

NOTEO - KRAMtrf JAN 1 a 1991

Information Services Section

Gentlemen:

Reference ls made to the follovlng plan received December 26, 1990:

Type Plan - Supplemer i l Pian of Exploration Leaae - OCS-C 5778 Block - 825 Area - Viosca Knoll A c t i v i t i e s Proposed - Wells D, E, and F

In accordance v i t h 30 CFR 250.33, this plan ls hereby deemed submitted and is nov being considered for approval.

Your control number is S-2578 and should be referenced in your communication and correspondence concerning this plan.

Sincerely,

(Orig. sgd.) A. Donald Giroir

^ J l l P D. J . Bourgeois Regional Supervisor F i e l d Operations

MTolbert: cck -.01/11/91: POECOM

D ORYX

January 3, 1991

Mr. Daniel Bourgeois Regional Supervisor, Field Operations Minerals Management Service Gulf of Mexico, OCS Region Off ice 1201 Elmwood Park Boulevard New Orleans, LA 70123-2394

Re: Amended Supplemental Plan of Explorati Viosca Knoll Block 825, OCS G 5778

Dear Mr. Bourgeois:

Oryx Energy Company hereby submits 7 copies (2 public and 5 conf ident ial) of an amended supplemental Plan of Exploration for the referenced lease for your review and approval. Please DELETE the "G" location as l i s ted below submitted with the supplemental Plan of Explorat ion.

LOCATION

SURFACE AND BOTTOM WATER LOCATION HOLE LOCATION DEPTH

VK 825 G Sur 5500' FEL and 5400' FSL 1705'

The "G" location was previously submitted as the revised "B" location in a revised Plan of Exploration dated January 2, 1991. Oryx intends to d r i l l the D-F locations contained in the supplemental Plan of Exploration pending the results of the "B" location.

Oryx Energy Company also submits 10 copies of the environmental report, discharge volumes for the new wells, air emissions data, and a CZM certificate for the state of Alabama.

Everything else in the POE remains the same.

Sincerely,

Alfred P. Norwood Conservation Manager

ABN:vak

Fryx Energy Company 14950 Heathrow F o r m Parkway

PO Box 1501 Houtlon TX 77251-1501 713 985 •-•OOH

Guir Coast Production Region

in

;'UdLiC INFORMATION POE/91006 - (2)

WASTES AND POLLUTANTS

Discharge Volumes (per well)

CSG SETTING HOLE EROSION CUTTINGS DRLG MUD SIZE DEPTH SIZE FACTOR VOLUME VOLUME (BBL) FT'

30"

20"

13 3/8"

9 5/8"

7 5/8"

5 1/2"

TOTALS

300'

1000'

3000'

8000'

10000'

13000'

Jetted

26"

17 1/2"

12 1/4"

8 1/2"

6 3/4"

0%

30%

30%

40%

40%

40%

900

3,353

4,340

5,314

1,024

988

15,919

Sea water

597

773

947

182

174

2,673

DISCHARGE

Drill mud

Drill cuttings

Sewage

Domestic waste

Water di s t i l l a t i o n uni ts

B.O.P. Solution

Cooling water

Ballast

Deck drainage

RATE/QUALITY COMPOSITION TREATMENT DISPOSAL

1000 bbl/hour Drill mud & fresh water

2,057 gpd

7,650 gpd

7,500 gpd

80,000 gpd

125 gpd

Subsurface sedlmpnt

Treatsd waste

Shower, wash & gal ley water

Salt water

Nonpolluting soluble solution

4,214,000 gpd Sea water

None

600 gpd

Sea Water

Fresh water

None

None

C/erboard

Overboard

Aerobic Overboard digestion

None Overboard

None

None

None

None

Overboard

Overboard

Overboard

Overboard

011/water Overboard sep.

POE/91003 - (1)

AIR EMISSION CALCULATIONS RIG: SONAT DISCOVERER 534 TYPE: DRILL SHIP

EQUIPMENT ENGINE FUEL USAGE FUEL USED

BALING (#/HPHR) HOURS RUN/DAY (GAL/DAY) DRILLING DAYS

PRIME MOVER EMD MD 20-E9 3600 0.396 24 4835.3 365 PRIME MOVER EMD MD 20-E9 3600 0.396 24 4835.3 365 PRIME MOVER EMD MD 20-E9 3600 0.396 24 4835.3 365 PRIME MOVER EMD MD 12-E8 1650 0. 42 24 2350.5 365 AUXILIARY CAT D398 825 0.385 1 44.9 365

TAV-12 CO 365 0.0 365 0.0 365 0.0 365

TRANSPORTATION 1250.0 365 0.0 365 0.0 365 0.0 365

TOTAL 18151.11

(Note: only three of six prime movers will be jsed unless dynamic positioning 1 s u

TSP (TONS) SOx (TONS) NOx (TONS) HC (TONS) CO (TON*

29.56 27 53 413.86 33.09 90.01 29.56 27 53 413.86 33.09 90.01 29.56 27 53 413.36 33.09 90.01 14.37 13 38 201.18 16.09 43.75 0.27 0 26 3.84 0.31 0.84 0.00 n 00 0.00 0.00 0.00 o.on o 00 0.00 0.00 0.00 0.00 0 00 0.00 0.00 0.00 0.00 0 00 0.00 0.00 0.00 7.64 7 12 106.99 8.55 23.27 0.00 0 00 0.00 0.00 0.00 0.00 0 00 0.00 0.00 0.00 0.00 0 00 0.00 0.00 0.00

110.98 103 36 1553.62 124.23 337.81

POE/91004 - (1)

• SUMMARY OF EXEMPTION

CALCULATION INFORMATION

D (MILES) (FROM NEAREST

POLLUTANT FORMULA LAND) _

TSP E = 33.3D 65 SOx E = 33.3D 65 NOx E = 33.3D 65 HC E = 33. 3D 65 CO E = 3400D2/3 65

PROJECTED "E"' EMISSIONS EMISSIONS

(T/yr) (T/yr) (-E)

2165 110.98 YES 2165 103.36 YES 2165 1553.62 YES 2165 124.23 YES 55,042 337.81 YES

AIR EMISSION FACTORS OBTAINED FROM EPA-AP-42 APPENDIX C SUPPLEMENT 9

POE/91004 - (2)

• ! • ^ S ^ ^ f r i . ^ b * , ^ . . . . , . . _ u . i » . . - M ^ ^ M ^ - ^ ^ ^ ^ ^ m 'Mmm l i f * . f t * * . - . n o n e t s • ^ : . i -

06/18/90

ENVIRONMENTAL REPORT

FOR

PLAN OF EXPLORATION

VIOSCA KNOLL

BLOCK 825

OCS-G 5778

DIRECT INQUIRIES TO:

Alfred B. Norwood Conservation Manager

ORYX ENERGY COMPANY P. 0. BOX 1501

HOUSTON, TX 77251-1501 (713) 985-2092

_. • - • ' . .. '-' - • I . DESCRIPTIOM OF PROPOSED ACTIONS

A . Oryx Energy Company proposes to continue exploratory d r i l l i n g operations

i n Viosca K n o l l , Block 825, OCS-C-5778 f o l l o w i n g the d r i l l i n g of the "3"

l o c a t i o n submitted i n the Plan of Exploration as revised. D r i l l i n g on

the »B" l o c a t i o n i s scheduled to begin i n February, 1991.

Transportation of material, supplies, and personnel between Viosca Knoll

Block 825 and Oryx Energy Company's onshore fac i l i t i es at Venice,

Louisiana, w i l l be by boat or helicopter. One craw boat and one supply

boat are prepared to service the rig dally. The frequency of helicopter

flights for transportation of d r i l l i ng personnel 1s estimated at one

round t r i p a day. The travel distance between Viosca Knoll, Block 82 5

and Venice, Louisiana Is about 170 miles round t r ip .

Louisiana Highway 23 1s the primary means of land transportation to

Venice, and provides an adequate access to the Gulf of Mexico. Community

growth and vehicular t ra f f ic 1s not expected to Increase during the

dr i l l ing operation; therefore, no additions! faci l i t ies are required to

conduct this operation,

B. This exploration endeavor wi l l require ap^/oxl mately 80 d r i l l i ng person­

nel. For each seven day working schedule, one Conpany supervisor and 40

contract workers wil l be required for the rig operation.

There wi l l also be two onshore base dispatchers each working 12 hour

tours per 24 hour day. One Company and four contract employees will be

•MM

responsible for loading and t ransferr ing supplies from the Venice

Shorebase to the work boats. Work boats, crew boats, and In certain

emergencies, helicopters w i l l be used as the transferr ing agent to the

r i g . The work boats w i l l require a crew of five people, changing out

every seven days.

C. There w i l l be no addit ional support f a c i l i t i e s needed. for the proposed

a c t i v i t y .

D. There 1- no requirement for the use of new or unusual technology 1n the

d r i l l i n g of the proposed wel ls .

E. See Exhibi t No. 1 for the map showing the location o f the proposed

a c t i v i t y In relat ion to the Louisiana and Alabama Coastal Zones.

F. No plans of development/production are in progress at th is time.

I I . DESCRIPTION OF THE AFFECTED ENYIROHHENT5 AND IHPACTS

A. Physical and Environmental

1. The proposed si te of d r i l l i n g 1s located approximately 85 miles cast

of Venice, Louisiana In 1600 feet of water. Viosca Knol l , Qlock

825, l ies beyond the outer l im i t s of the major f i n f i sh and

indust r ia l bottomflsh harvest area and Just outside the pr incipal

3

royal red shrimp harvest areas. This exploratory operation should

not have any s ign i f icant Impact on these resources,

Viosca Knoll Block 825 Is well beyond the closest shipping fairway.

Any supply vessels going through or near any fairways w i l l exercise

due caution. All required navigational aids w i l l be instal led on

the d r i l l i n g vessel and be kept In good working order.

Water depths at the d r i l l i n g locat ion average 1500 feet. Because

th is s i te is about 65 miles frcm shore, recreational boats are

un l i ke ly to be In the area. This d r i l l i n g operation should not

In ter fere with any recreational or commercial f ishing ac t i v i t i e s .

Seismic analysis has been conducted and nc shallow gas zones are

indicated at the selected well locations. Therefore, no

unmanageable cas Is expected, however, a d r i l l i n g engineer w i l l be

prepared to accommodate shallow gas, I f encountered.

There are no marine sanctuaries, w i l d l i f e refuges, or preserves In

the immediate srea of Viosca Knoll Block 825, and since the ent ire

coast l ino can be considered environmentally sensit ive In varying

degrees, there is no benefit to l i s t i n g the major bays and state and

federal w l l d i i f a refuges along the coast. Prudent operations and,

4

...... .. ——>ww i —ww—11 'JESSE

i f necessary, employment of ti.e "Oryx Energy Oil Sp i l l Contingency

Plan" should minimize Impact to the area.

To the best of our knowledge, hydrocarbons are the only mineral

resources to be developed in this area.

Avai lable Information indicates there has been no dumping of

mater ials on the lease In the past. The poss ib i l i t y exists that

mater ials l e f t by other operators in the area may 1n fact be present

on the ocean f luur. Upon completion of operations, Oryx Energy

w i l l conduct a side scan sonar survey to ver i fy that the d r i l l i n g

locat ion 1s l e f t free of any obstruct ions. Al l d r i l l cut t ings,

d r i l l i n g mud, sanitary wastewater and cooling water discharged

during th is operation w i l l be In compliance with U.S. Coast Guard,

EPA Permits and 30 CFR 250.40.

Five species of marine tu r t les occur In the Gulf of Mexico. These

are the Loggerhead, Green Sea Tur t le , Kemps Ridley, Hawksbill, and

the Leatherback. Al l f ive of these tu r t les are on the endangered or

threatened species l i s t . Some of the marine mammals that could be

present in the Gulf of Mexicc are the Sperm Whale, Black Right

Whale, Humpback Whale, Sei While,. F1n Whale; a l l of these are also

on the endangered species l i s t . The Brown Pelican, also Included on

the endangered species l i s t , is known to reside along tha Louisiana

Gulf Coast, Although the above mentioned species are not commonly

seen in the immediate area, they could be affected by an o i l s p i l l

I f one were to occur; however, they have not been documented as

haying been directly affected by spills 1n the past, The

probability of an oil sp i l l from this operation 1s very small and

would be covered by fast response under the "Oryx Energy Oil Spill

Contingency Plan."

9. The results of air quality analysis *s detailed In the Plan of

Exploration shew that projected gaseous emissions from the proposed

operations fall a great deal below the emission exempt'on levels as

derived from EPA Reports AP-42, June and August 1977 and will have

negligible impact due to dispersion by winds.

10. The water depth at the proposed locations is greater than AOO meters.

The maximum extent of reach of the anchors at the proposed locations

for a semisubmersible r i g i s approximately 5000 feet. A chemosynthetic

survey has bben run. The anchor patterns for each location w i l l be

submitted with each APD. To prevent the p o s s i b i l i t y of impact to

these potential chemosynthetic communities, the anchors and chain

w i l l be set to avoid these habitats.

Socio - Economic

The primary service f a c i l i t y for this operation will be at Venice,

Louisiana. Personnel and supplies to support the operation will be

transported from this f a c i l i t y ,

6

1. The d r i l l i n g r i g to be used Is a seml -su tmers lb le d r i l l i n g u n i t . I t

is expected to be on s i t e by mid

2. As a general r u l e , a l a rge d r i l l i n g r i g of the type to be used w i l l

r e q u i r e atout 80 persons o f f s h o r e w i t h onshore support o f

approx imate ly 20 persons. Since the f a c i l i t y is a l ready

e s t a b l i s h e d , and the d r i l l i n g r1g personnel do"not normal ly l i v e i n

the a f fec ted a rea , no adverse Impact cn the co; .nuni ty should

o c c u r . To the c o n t r a r y , the opera t ion should have a p o s i t i v e Impact

on s t a b i l i z i n g employment and s t i m u l a t i n g general bus iness .

3. The supp l ies o f d r i l l i n g equipment, energy, food , water and the l i k e

are adequate end I t is a n t i c i p a t e d t ha t t h i s proposed a c t i v i t y w i l l

have l i t t l e e f f e c t on cu r ren t l e v e l s o f consumption. Therefore, no

s i g n i f i c a n t economic or demographic adjustments are a n t i c i p a t e d .

I I I . UNAVOIDABLE ADYERSE IMPACTS

A. D r i l l i n g o f the proposed e x p l o r a t o r y we l l 1n Viosca Knol l Block 825w111

r e s u l t 1n the discharge o f d r i l l i n g mud and c u t t i n g s i n t o the waters o f

the Gul f o f Mexico. The discharge o f d r i l l t t l n g s w i l l bury s e s s i l e

benthic organisms in the l o c a l area ad jacent to the d r i l l i n g s t r u c t u r e .

The d isposa l o f mud may r e s u l t In a l o c a l minor decrease o f primary

p r o d u c t i v i t y due to the m o r t a l i t y or f unc t i ona l impairment o f

7

phytoplankton and algae In the area of high tu rb id i t y . A large o i l s p i l l

could resu l t In retarding product iv i ty of the phytoplankton cnmmunities,

therefore, a l ter ing the community structure for an unknown period of

time. Oryx Energy w i l l use the necessary monitoring and control methods

to prevent contamination of the sea in accordance with 30 CFR 250.40.

Air emissions from combustion of fuol in r ig engines, boat engines, and

helicopters can affect the a i r qua l i ty near the offshore d r i l l i n g un i t

and near the onshore travel routes. In most cases, these emissions w i l l

be minimal, local 1n nature and w i l l be quickly dissipated by c l imat ic

condit ions. All engines w i l l be kept 1n good working condition to

minimize emissions. Highly v o l a t i l e , low molecular weight hydrocarbons

would be released into the atmosphere from a blowout wi th the release 0*

natural gas and crude o i l . These hydrocarbons would cause some a i r

pol lut ion and degradation. I f a blowout resulted 1n a f i r e , large

amounts of part iculate carbon and oxides of carbon, along with smaller

but unknown amounts of sul fur oxides, v o l a t i l e h;1rccarbcns and p a r t i a l l y

oxidized compounds would enter the a i r . Local a i r vculd bs severely

degraded for the duration of the f i r e . The extent of degradation is

undeterminable but I t 1s unl ikely that 1t would be a s ign i f icant or long

term a f fec t on land resources.

The r isk and outcome of these impacts are Just i f ied In that presently the

only a l te rnat ive would be not to d r i l l at a l l . The need for new energy

reserves on a national level far outweighs the minimal and local

environmental impacts that could possibly occur.

8

D. The propoaed activity wi l l be carried out and completed with the

commitment t h n :

1. The best available and safest technologies wi l l be uti l ized

throughout the project. This includes meeting all applicable

requirements • for equipment types, general project layout, safety

systems, and equipment and monitoring systems.

2. All operations wi l l be covered by Oryx Energy Company's Oil

Spill Contingency Plan, which was approved by Minerals Management

Service in February 1933,

3. All applicable Federal, State and local requirements regarding air

emissions, water quality, and d r i l l i ng associated discharges for the

proposed activities as well as any other permit conditions, wil l be

complled with.

9

REFERENCES

I . U.S. Department o f I n t e r i o r , Minera ls Management Serv ice .

Fina 1 Environmental Impact St atement - Central and Western Planning.

Areas, Gul f o f Mexico. Washington, O . C , August 1988.

2. U.S. Department u f I n t e r i o r , Mineral Management Serv ice .

Final Regional Environmental Impact Statement - Gulf o f Mexico.

Washington, D . C , October. * 337.

3. U.S. Department o f I n t e r i o r , Minera ls Management Serv ice .

Final Regional Environmental Impact Statement - Gu l f o f Mexico.

Washington, D . C , January 1983.

4. U.S. Envi ronmental P ro tec t i on Agency, 1977. Compilat ion o f A i r P o l l u t i o n

Emission F a c t o r s , 3rd E d . , AP-42.

5. Zingula, R. P. 1975. "Ef fects of D r i l l i n c Operations on the Marine

Environment." Environmental Ascects of Cnemical Use in Well D r i l l i n g

Operations. EPA-56011-75-004,

IC

01/02'91 15:50 ORYX ENERGY - OFFSHORE HOUSTON 002

COASTAL ZONE MANAGEMENT PLAN

CONSISTENCY CERTIFICATION

Plan of Exploration

Viosca Knoll Block B25

OCS-G-5778

The proposed activities described 1n detail 1n the Plan comply with the State of Alabama's Coastal Zone Management Program and will be conducted in a manner consistent with such Program.

Manager, Offshore Operations Certifying Officer

ORYX ENERGY COMPANY

a ORYX

o n Oryx Energy Company I IttSO Heathrow Kotrsi Park* PO BOK 1501 Houi ion r x 772.M-I50I 713 9H5 2000

December 20, 1990

Gulf (oast

Production Region

Mr. Daniel Bourgeois Regional Supervisor, Field Operations Minerals Management Service Gulf of Mexico, OCS Region Office 1201 Elmwood Park Boulevard New Orleans, LA 70123-2394

Re: Supplemental Plan of Exploration Viosca Knoll Block 825, OCS G 5778

Dear Mr. Bourgeois:

Oryx Energy Company hereby submits ten copies (5 public and 5 confidential) of a supplemental Plan of Exploration for the referenced lease for your review and approval. Drilling operations are planned to begin as early as February 1, 1991; therefore, your expedited approval is requested.

Oryx has determined that more wells will be needed to identify possible hydrocarbon accumulations.

LOCATION

VK 825

LOCATION SURFACE AND BOTTOM HOLE LOCATION

WATER DEPTH

D Sur 600' FEL and 5200' FNL 1550'

E Sur 5925' FEL and 7300 FSL 1650'

F Sur 7000' FEL and 6700 FSL 1660'

G Sur 5500' FEL and 5400 FSL 1705'

A Bathymetry map, seismic lines, structure maps and shallow hazards statements are attached.

Oryx believes that the structure map and well plat submitted with this plan to be exempt from public disclosure. Oryx requests that the data and information enclosed herewith be dispersed for use only by the United States Government. Oryx intends to d r i l l the G location f i r s t and since the anchor locations for this well w i l l need to be cleared for chemosynthetic communities, the shallow

PUBUC INFORMATION 90549A - (1)

hazards report for the anchor locations is included. Oryx will submit the anchor patterns for the remaining wells with the APD.

Several wells have been drilled in this area with no indications of H2S Including several wells on Block 825; therefore, i t is recommended tl.at this area be classified as a "zone where the absence of HZS has been confirmed."

An oil spill trajectory analysis for tin's lease is attached.

Everything else in the POE remains the same.

Sincerely,

Al fred B. No-wood Conservation Manager

ABN:vak Enclosures

90649 - (2)

SHALLOW HAZARD EVALUATION VIOSCA KNOLL BLOCK 825 - PROPOSED LOCATION "D"

5200' FNL & 600' FEL (Surface Location) TOTAL DEPTH: 12,750' SUBSEA

The water depth at proposed location "D" is approximately 1550'. The seafloor in the vicinity of the proposed location is smooth and slopes at 2 degrees (or 184' per mile) to the south.

The shallow hazard survey 4.2 kilojoult Sparker and 7 kilohertz Subbottom Profiler records were examined for the presence of shallow amplitude anomalie and faulting in the vicinity of the "D" location. In addition, the 3-D seismic records were also checked. These inspections confirm the lack of any shallow faulting or amplitude anomalies which could cause drilling hazards. This is confirmed by the RACAL GEOPHYSICS high resolution geophysical report which accompanied the raw data.

The subbottom profiler records indicate the sediments immediately beneath the sea floor are soft with a high water content. This interpretation is based on the acoustically transparent nature of thi section. Underneath this zone are closely spaced parallel continuous reflectors most likely representing highly stratified sediments. There is no evidence of slope instability or slumping in the vicinity of the proposed "D" location.

ORYX ENERGY COMPANY

Manager of Geophysics Gulf of Mexico East District

1060/12-10 - (1)

SHALLOW HAZARD EVALUATION VIOSCA KNOLL BLOCK 825 - PROPOSED LOCATION "E"

7300' FSL & 5925' FEL (Surface Location) TOTAL DEPTH: 11,400' SUBSEA

The water depth at proposed location "E" is approximately 1650'. The seafloor in the vicinity of the proposed location is smooth and slopes at 2 degrees (or 184' per mile) to the south southeast.

The shallow hazard survey rt.2 kilojoule Sparker and 7 kilohertz Subbottom Profiler records were examined for the presence of shallow amplitude anomalie and faulting in the vicinity of the "E" location. In addition, the 3-D seismic records were also checked. These inspections confirm the lack of any shallow faulting or amplitude anomalies which could cause dr i l l i n g hazards. This is confirmed by the RACAL GEOPHYSICS high resolution geophysical repo.-t which accompanied the raw data. The proposed "E" wellbore will cross a major down to the north fault at 8550' subsea. This same fault has been cross previously and did not result in any problems. However, our engineer's have been informed of this and w i l l take the necessary precautions when this fault is crossed.

The subbottom profiler records indicate the sediments immediately beneath the sea floor are soft with a high water content. This interpretation is based on the acoustically transparent nature of the section. Underneath this zone are closely spaced parallel continuous reflectors most likely representing highly stratified sediments. There is no evidence of slope instability or slumping in the vicinity of the proposed "E" location.

ORYX ENERGY COMPANY

Manager of Geophysics Gulf of Mexico East District

1D60/12-10 - (2)

SHALLOW HAZARD EVALUATION VIOSCA KNOLL BLOCK 825 - PROPOSED LOCATIO* "F

6700' FSL & 7000' FEL (Surface Location) TOTAL DEPTH: 12,000' SUBSEA

The water depth at proposed location "F" is approximately 1660'. The seafloor in the v i c i n i t y of the proposed location is smooth and slopes at 2 degrees (or 184* per mile) to the south sou'.neast.

The shallow hazard survey 4.2 k i lo jou le Sn;; <er and 7 ki lohertz Subbottom Prof i le r records were examined for the presence of shallow amplitude anomalie and fau l t i ng in the v i c i n i t y of the "F" locat ion. In add i t ion , the 3-D seismic records were c^so checked. These inspections confirm the lack of any shallow faul t ing or amplitude anomalies which could cause d r i l l i n g hazards. This is confirmed by the RP 'AL GEOPHYSICS high resolut ion geophysical report which accompanied the raw data. The proposed "F" wellbore w i l l cross a major down to the north fau l t at 8050' subsea. This same f a u l t has been cross previously and did r.r.t resul t in any prcblems. However, our engineer's have been informeJ of th i and w i l l take the necessary precautions when this fau l t is crossed.

The subbottom pro f i le r records indicate the sediments immediately beneath the sea f loor are sof t with a high water content. This in terpre ta t ion is based on the acoustical ly transparent nature of the sect ion. Underneath th is zone are closely spaced paral le l continuous re f lec tors most l i ke ly representing high s u a t i f i e d sediments. There is no evidence of slope i n s t a b i l i t y or slumping in the v i c i n i t y of the proposed "F" location.

ORYX ENERGY COMPANY

J . h\ Wilborn Manager of Geophysics Gulf o f Mexico East D i s t r i c t

1D60/12-10 - (3)

SHALLOW HAZARD EVALUATION VIOSCA KNOLL BLOCK 825 - PROPOSED LOCATION "G"

5400' FSL & 5500' FEL (Surface Location) 5450' fSi * 3250' FEL (Bottom Hole Location)

TOTAL DEPTH 7700' SUBSEA

The water depth at proposed location "G" is approximately 1705'. The seafloor in the vicinity of the proposed location is smooth and slopes at 1.2 degrees (or 110' per mile) to the south southeast.

The shallow hazard survey 4.2 kilojoule Sparker and 7 kilohertz Subbottom Profiler records were examined for the presence of shallow amplitude anomalie or faulting in the vicinity of the "G" location. In addition, the 3-D seismic records were also checked. These inspections confirm the lack of any shallow amplitude anomalies which could cause dri l l i n g hazards. This is confirmed by the RACAL GEOPHYSICS high resolution geophysical report which accompanied the raw data. The proposed "F" wellbore w i l l cross as small shallow fault at 3383' subsea and a major down to the north fault at 5550' subsea. This major fault has beon cross previously and did not result in any problen:s. However, our engineer's have been informed of this and will take the necessary precautions when this fault is crossed.

The subbottom profiler records indicate the sediments immediately beneath the sea floor are soft with a high water content. This interpretation is based on the acoustically transparent nature of the section. Underneath this zone are closely spaced parallel continuous reflectors most likely representing high stratified sediments. There is no evidence of slope instability or slumping in the vicinity of the proposed "G" location.

ORYX ENERGY COMPANY

J. H. Wilborn Manager of Geophysics Gulf of Mexico East District

1D60/12-10 - (4)

CHEMOSYNT' ZTiC ANALYSIS VIOSCA KNOLL BLOCK 825 - PROPOSED LOCATION "G"

5500' FEL 4 5400' FSL (Surface Location)

The proposed anchor pattern w i l l effect the seafloor from a radius of 4000' out to 6000' from the proposed "G" surface location. The anchors will not effect the seafloor at a radius greater than 6000'.

The anchor pattern has been drawn on the "Oceaneering International Chemosynthetic Organism Survey" map. The bow heading of the rig is 14.5 degrees. Only anchors 2 & 3 wi l l be placed in the area covered by the survey. With this bow heading anchor 2 will be placed 1000' feet north of the nearest chemosynthotic organism community and anchor 3 will be placed 1000' southwest of its nearest chemosynthetic organism community. No others anchors will be placed within 3500' of the nearest chemosynthetic organism community.

Anchors 1, 5, 6, 7 & 8 will be set on undisturbed seafloor underlain by parallel reflectors. Anchor 4 will be placed on a slump feature dipping at 10 degrees to the south.

ORYX ENERGY COMPANY

J. H. Wilborn Manager of Geophysics

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OIL SPILL TRAJECTORY ANALYSIS

In the event a spill occurs from this area Oryx has projected the trajectory of a s p i l l utilizing information in the draft Environmental Impact Statement (EIS) for OCS Lease Sales 131/135/137.

The EIS contains oil spill trajectory simulations using seasonal surface currents coupled v/ith wind data, adjusted every 3 hours for 30 days or until a target 1s contacted.

Hypothetical spill trajectories were simulated for each of the potential launch sites across the entire Gulf. These simulations presume 500 spills occurring 1n each of the four seasons of the year. The results In the EIS wer*» presented as probabilities that an oil spill beginning from a particular la-.ich site would contact a certain land segment within 3, 10, or 30 days.

The trajectory analysis Indicates that there 1s a negligible chance that a spill originating from this lease w i l l contact land within ten days (see table IV-17 pp IV 85). An oil spill originating from this lease will be closely monitored as 1t approaches land and the most likely land segments to be affecied w i l l be determined utilizing the most recent trajectory analysis. Environmentally sensitive areas which could be affected w i l l be determined using the CGA maps contained 1n Section V, Volume I I of the CGA nanual. This manual also Includes containment/cleanup protection response modes for the sensitive areas.

Section VI, Volume I I of the CGA Operations Manual depicts the protection response modes that are applicable for oil spill cleam-p operations. Each response mode 1s schematically represented to show optimum deployment and operation of the equipment In areas of environmental concern. Implementation of the suggested procedures assures the most effective use of the equipment and will result 1n reduced adverse Impact of oil spMls on the environment. Supervisory personnel have the option to modify the deployment and operation of equipment to more effectively respond to site-spedf 1c circumstances.

In the event of an oil s p i l l , the f i r s t available vessel w i l l be dispatched to the Venice, La. Clean Gulf Associates (CGA) location. As soon as clean up contractor personnel arrive, the equipment w i l l be loaded out and the vessel will be on i t s way to the spill site. During normal business hours, 1t 1s anticipated that clean up personnel w i l l be able to reach Venice 1n approxi­mately 1 1/2 hours and 2 1/2 hours at other times. This time will be reduced to approximately 1 hour 1f helicopters are available at the time of the call out.

Assuming that a vessel 1s available 1n Venice at the time of the Incident, the time to respond will be:

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Venice to Block 825 (80 miles) Equipment Deployment Equipment Loadout Cleanup Personnel

8.0 hours .5 hours

2.0 hours 2.0 hours

12.5 hours

Assuming that the vessel is available in Fourchon at the time cf•the incident, the time to respond will be:

Fourchon to Venice (35 miles) Venice to 825 (80 miles) Equipment Deployment Equipment Loadout

3.5 hours 8.0 hours 0.5 hours 2.0 hours

14.0 hours

Deployment time for Cleanup Personnel 1s 2 hours which is less than the vessel travel time from Fouchon to Venice; therefore, no additional time was included.

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