f n Rtrptf * \ f i r T t : AUG I 51985

' j immi*ti Sftvraeft fcjq>li r#r. i >n Cowpany lit.CC'fftKW! Hr, 4 >:. f*'|V--y 3040 »o*t t#K BW**va tM, Sui te 221*0

f t \ 1 I «****!

*v*errnc> siedi / «ur I n i t i a l Plan • * Eaplvratt txf l a«wt f'nvf rt-f»vn«-«l Report r*C*|»«d August 6 , 1 % * ! , L « * « OC^-r, C3r»t>, Block 177, &ai*« A r M . T h U plan Includes rlw • C t t v t t t e * prn.pt-.«;»<• !'«r J M H A '.ftrru-jlt t ,

i i t accordance tfffiH 3f CF* 230.34, r*¥l««td Pec«lrt»*r 1 1 , I t / 9 , .mt oyr l - t w r t u t t i t January ?9, 19>9, r h l p l a n bw f l d » i t m i i w j l tc 6* c v o p l l U a i r.f IMiSMtt I H , aixt I f now feting c«n^<fcred f r *nun>*a l .

Yr«r p U n Control maab'r I j n-224" *n<l t fenriu r, « f o r e f C « d I n y«m" cuNMfUce* i t r n and cor r t f ^cwdtuce ca fKv f i i t oy i M n p 1 * * .

hcc: L « H * OCS-C 635b (0PS-3-2i ( f l u : W # t f ^ w/rut>Mc In« •. Cony t>f t»w p lan and E» trWSLTC UCORDS «00M)

W - 3 — —

hUTo1)Mrt : f lC*t3/U/&§ uMIr IC

» . « . N«,Wa«

?tl l*5 and »t>MMfCt l e *

rw • A !

: o »> m$

PLAN r EXPLORATION

jARDEN BANKS AREA

BLOCK IT>

OCS-G-6 355

)FFSHORE, LOUISIANA

J u l y 29, 1985

1' U B L I C I S F R *» A T I O N

OktmtMW fkVWMk IflplMNWI 0WHP*>V * SubtxMry o« 0 «nv>"d S»#w» ' Sw'» 2200 3040 POM Oa* Br.u"#»»'<l Houston T«-MS "f)MS PNMM "3 980'36'

6b Exploration Compan;

TABLE OF CONTENTS

Description of and Schedule for Exploration A c t i v i t i e s

Description of Rig and Safety Equipment

Geophyaical Equipment

Location of Proposed Wells

Current I n t e r p r e t a t i o n

/ther Information

Appendix

DESCRIPTION OF PROPOSED ACTIVITY

The Exploration Plan for Garden Banks 177, OCS-G-6 355,

c a l l s f o r the possible d r i l l i n q and comoletion of Five

(5) exploratory wells. The f i r s t well i s scheduled to

spud on August 31, 1985 and should be completed by

October 4, 1985. The second well w i l l spud on October 5,

1985, and remaining wells d r i l l e d according to the dates

shown below. Depending on the results of the f i r s t two

wells and duration of the planned a c t i v i t i e s , the proposed

schedule i s as follows:

DESCRIPTION OF ACTIVITY PROPOSED DATE DURATION

Move in GB 177; D r i l l 6

Complete Well No. Aj Move Out Auqust 31, 1985 20 daya

Move in GB 177; D r i l l 6

Complete Well No. B; Move Out October 5, 1985 20 daia

Move in GB 177; D r i l l fc

Complete Well No. Cl Move Out November 10, 1985 30 days

Move i n GB 177; D r i l l fc Complete Well No. D; Move Out December 26, 1985 28 days Move in GB 177; D r i l l fc Complete Well No. E; Move Out February 7, 1986 28 days

DESCRIPTION OK RIG AND SAFETY EQUIPMENT

The proposed locations w i l l be d r i l l e d with a semisubmersible

r i q s i m ilar to the Zapata Neptune. Included in the Appendix

are pages 1 through 5 which qive specifications f o r the

Zapata NeDtune. The specifications for the actual d r i l l i n g

vessel and safety equipment to be used w i l l be submitted

along with the application for permit to d r i l l . The d r i l l i n g

r i g used to d r i l l the exploratory wells under the subject

plan w i l l contain and maintain various safety equipment i n

accordance with OCS Order No. 2; such as diverter system,

blowout preventers, a u x i l i a r y equipment, and mud tes t i n g and

monitorinc equipment.

- 1 -

Drilling operations w i l l ba conducted in a manner so as

to maximize pollution prevention in accorance with OCS

Order No. 7. A l l other safety and control equipment w i l l

be utilized in accordance with other applicable OCS orders.

Should the well(s) indicate the presence of commercial

reserves, mudline abandonment equipment wi l l be utilizod

to f a c i l i t a t e completion of the well at a later date.

GEOPHYSICAL EQUIPMENT

All geophysical work preparatory to the commencement of

exploratory d r i l l i n g operations has been completed. No

other geophysical work i s presently planned for this

lease. I f i t is subsequently determined that additional

work i s required, conventional CDP reflection methods

w i l l be used.

LOCATION Of PROPOSED WELLS

Attached is a Vicinity Map (Figure 1) which shows the

location of Garden Banks Block 177 relative to the shore­

line. The location Plat (Figure 2) provides the surface

and target locations for each well.

CURRENT INTERPRETATION

Attached i s the subsurface structure map (Figure 3) which

reflects the current geological data in the area. These

data are considered confidential by Diamond Shamrock

Exploration Company and should be exempt fron disclosure

under the Freedom of Information Act (U.S.C. 552). These

data are intended for use by the Minerals Management Service

personnel only.

OTHER INFORMATION

In accordance with OCS Order No. 7, Diamond Shamrock

Exploration Company has on f i l e an Oil S p i l l Contingency

Plan approved by the Minerals Management Service.

-2

Diamond Shamrock Exploration Company is a member of the

Clean Gulf Associates (CGA) and, as such, has access to

the stock Dile of o i l s p i l l containment and clean-up

materials for use in offshore estuarine areas. Attached

are Figure 4 and Tables 1 through 4 which provide the

location of the CGA f a c i l i t i e s , and a description of the

personnel, equipment, and material used to control and

clean up o i l s p i l l s . Based on the distance from the CGA

i n s t a l l a t i o n s to Garden Banks Block 177, we estimate a

travel and deployment time of approximate'y 24 hours.

Intersea Research has conducted a hazards and archeological

survey for Diamond Shamrock Exploration Company covering

the area of the proposed locations. Three copies of a

report of t h i s information have been previously submitted

to the Minerals Management Service. The locations proposed

in t h i s plan are free of any bottom or sub-bottom features

which might pose a hazard to future d r i l l i n g operations,

nor are they located near to any magnetic anomalies.

The onshore support base for the proposed a c t i v i t i e s is

the Cameron Offshore Service Dock at Cameron, Louisiana.

This f a c i l i t y normally handles personnel and supplies

transported by boat or barae. This f a c i l i t y w i l l also

handle tubular goods, heavy suopl ies and bulk materials.

Personnel transported by helicopter may be picked up and

returned to t h i s f a c i l i t y or to A i r Logistics' base i n

Intercoastal C i t y , Louisiana. Helicopters w i l l make t^ree

(3) round t r i p s to the w e l l s i t e per week. Each crewboat

and work boat w i l l make one round t r i p per day to the w e l l -

s i t e with 2 ho s and 4 hours standby time respectively.

Table 5 of the Appendix is a l i s t i n g of d r i l l i n g mud

components and mud additives which are normally used during

-3-

An Environmental Report and Air Quality Review Report

concerning the subject work has been prepared by

John E. Chance and Associates and accompanies t h i s plan.

Table 6 of the Appendix shows t o t a l quantity discharged,

rates of discharge, method of discharge, and the basis

for determining each of the above values for a l l s o l i d

( i e . d r i l l cuttings) and l i q u i d wastes ( i e . b a l l a s t

water). An NDPES disposal permit has been f i l e d with

the Environmental Protection Agency (EPA). We understand

that there may be a question as to whether the e x i s t i n g

Gulf of Mexico General NDPES Permit No. TX 0085642 would

cover d r i l l i n g operations conducted subsequent to the

expiration of the e x i s t i n g general permit. Diamond Shamrock

believes that exploratory d r i l l i n g operations may be con­

ducted under TX 0085642, in view of the fact that the permit

has been automatically continued as to a l l terms by the

Administrative Procedure Act [5 U.S.C. i 553 ( c ) ] . Current

d u l l i n g vessel commitr.;ents and other v i t a l business con­

siderations mandate that Diamond Shamrock proceed with

d r i l l i n g operations on t h i s lease t r a c t s .

-4-

D i a m o n d S h a m r o c k Exploration Company

July 30, 1985

United States Department of Interior Minerals Management Service Gulf of Mexico Region P. O. Box 7944

Metairie, Louisiana 70010-7944

Attent ion: Mr. I). W. Solanas

Reference: Ran of Exploration

Gentlemen:

A high resolution geophysical survey was conducted to evaluate the potential shallow hazards in Garden Banks Block 177 and o clear the proposed locations as stated in the Plan of Exploration for the above nentinned block.

The interpretations were made from the following data:

1. Echo-Sounder records - Bathymetry 2. Sub-bottom Profiler - 75 to 100 m. penetration 3. Mini-sleeve exploder - 100 to 750 m. penetration 4. Side-scan Sonar - sea floor features 5. Magnetometer

The surface locations as proposed in the Plan of Exploration are free and clear of shallow, gas-bearing zones and shallow faults or sea floor depressions. All due caution wil l be exercised in dri l l ing any location.

Very truly yours,

ONHNWW Shameck Eipfcxatxxi Company •'.

Garden Banks Block 177 OCS-G-8355

Mark S. Bauer Distr ict C jophysicist - Offshore

MSB/mjr

•• (to .• :

*

APPENDIX

Specifications for "Zapata Neptune1

V i c i n i t y Map

Location Plat

Subsurface Structure Maps

Location of CGA F a c i l i t i e s

Summary of CGA Personnel

CGA Equipment anu Materials

D r i l l i n g Mad Components

Estimated Discharge Rates

Pages 1-5

Fiqure 1

Figure 2

Figure 3

Figure 4

Table 1

Tables 2-4

Table 5

Table 6

-slele

ZAPATA NEPTUNE Nominal water depth rating 1,500'

MuM Maaaaalaaa Driwiwa Bajataaaaal Semisubmersible with eight stabiliz­ing columns and two additional att buoyancy modules

Regis tered Panama Built 1977. Norway Drawworks National 1625 powered by 3 water Length Lower cooled eiectnc motors Total 3.000

H u l l s 355 HP intermittent 2.400 HP continuous Overal l W i d t h 221 Ma in Power He igh t of Plant 4 each Hedemore Diesels engines

s tab i l i z ing rated at 2200 BHP at 1200 rpm c o l u m n s 120 4 each AC generators Nebb model.

Main deck 1810 KVA total output 7240 KW. 8 length 227 unit SCR system

Main deck Pumps 2 National 12 -160 Triple* 1600 H P w i d t h 220 continuous. 2000 HP mtermittant

Dr i l l ing Rotary National C 495 with 49 v» table Draft 70 opening

Cranes 2 pedestal 'ow pressure hydraulic Riser Pipe cranes, type Hydraulic Bratt Vaag Equipment 1500 M Cameron 2 0 1 * " * v. m Load capacity 50 tons wan. 55 ft stroke slip |0<nt. Riser

Anchor ing tensioning syst«ffl by Rucker System 8 each Danforth type LWT anchors BOP Equipment Cameron 18,<' single stack system

30 000 lb Vic may 8 each 3 m with 2 10 00'J PSI WP Cameron type chain 5.100 ti long 4 each double U double ram preventers, and two A uca- windlasses 'ated pun Hydnl type GL 5000 PSl WP an 500 000 lbs ruaiar preventers

Propu ls ion Propulsion assistance 6.800 hp Substructure Goiar Nor with 1.456 000 lb Ma* a ts res je rotary capacity Dr i l l ing Derrick 160 Goia- Nor 1 000 000 'b Hook

Water 14 400 bbis •oad capacity under dynamic Potable conditions

Water 3 420 bbis Pipe Racking

Puai Oi l 16.960 ocis System Maritime Hydraulic semi-automatic

L iqu id M u d i .890 bbis 'acking ana iron roughneck model Total Bulk •MH976

M u d and Dril l Str ing Cement 18.000 cu ft Compensator Rucke' Model 18/400 18 ft siroke

Sack Storage 5 000 sacks Cement ing Unit BJ Hughes Sewage Treat ing Dri l l Cellar and

System Neptumatic Mode 90/90 70 MKU Dril l Pipe 9 ' / , CD • 3 " I D s 30 collars type. USCG approved 8 OD x 2 ID * 30 collars

Desa l in iza t ion 6 ' / } OD * 2V| 10 N 30 collars Unit i opetatmg i standby Atlas model 5 Heviwate Drill Pipe

Af G #5. Ma i cap 6 300 gai day 5 0 0 19 5 lb Grade E range 2 Hel ipor t Designed lo accommodate Sikorsky 5 0 0 19 5 lb Grade G. range 2

F61 N 5 0 0 19 5 lb Grade G. range 2

Quarters •ariers lor 86 men Personnel

Survival Four each 50 man Ha'dmg covered motor lite boats 7 esch Davit launched inflatable me boats

1

ZAPATA O F F - S H O R E CO

Z • I HAS

IMGINCCRIMO Or*«KTMCNT

M « M | « O C C

CMCCKIO

EH >=*Jtr

J V « 4 f

r ^

> 4

CAMCRON W I TVPt r SCK-tW MOM tm rr OD «Mto% m i MM © It C CiK I K 2%*

TOTAL HFJOKT OF K F 40 TOTAL WCOHT OF I O 340000 lot KTJOMCV MVCMAULC CONTROL SYSTEM M0»€*W£LLr\fu,VCON ACLiSTC BACK UF CONTROL SWIM

10P EQUIPMENT •LOWOUT PKEVEKTEK ITACK

I 3

• 3

• 3

8 3

• 3

6 )

8 3

8 3

4" fame rem .ollet Connector - 10,000 ps l . VP

4H Doubl* Cameron Type "U" blowout preventor 10,000 pal. VP - Lover Pipe Heat

4" Double CaaMroa Type "U" blowout preventer 10,000 pal. VP - Middle Pipe Haas

4" Double Cameron Type "U" blowout preventer 10,000 psl . VP - Upper Pipe lass

4" Double Type "U" blowout preventer 10,000 psl . VP -Shear

4" Hydril Type CL Annular Preventer, 5000 pel. VP

4" Cameron Collet Connector - 10,000 ps i . VP

4" Bydrll Type CL Annular Preventer, 5000 pal. VP

ALL FAIL SAFE VALVES are Cameron 3 1/16" 10,000 ps l . VP

5

GARDEN BANKS

GAROEN BANKS A-401

JLLgH ISLAND

0> A MC N D 'HAMMOCK

O C S - 6 - CSSS

A I R * A Y

/no ore**T,ON5 " I L L m COMOUCTiO /* TM

IS A*t*>

UTM ZONK IS 221

FIGURE 2

PUBLIC INFORMATION PREPARED • * JOHN E CHANCE A ASSOCIATES,INC

DIAMOND SHAMROCK

PLAN OF EXPLORATION PROPOSED LOCATIONS

GARDEN BANKS AREA

SCALE I "« 2000' T / 2 S / S S

Net-J

Tra in ing

A. Fast Response Open Sea and Say

B. High Volume Open Sea Skimmer (Launch and Retr ieve) Skimming

C. Shallow Water Skimmers

D. A u x i l i a r y Shal.ov Later Skimmers (per two u n i t s )

D. A u x i l i a r y Shallow Water Boom

F. He l i cop te r Spr.iy Svstems

F. B i r d Scarers

G. Communications System

i i c

Do Not Need Tra in ing

fl -JL 3-.

i H

5

3 Le (9)

•

Supervieory

d - Sometimes i t w i l l be desir . -^ le to have an ex t ra man on l o c a t i o n . Where t h i s symbol appears p rov i s ion can be made to handle t h l a a d d i t i o n a l man.

TABLE 2

EQUIPMENT AND MATERIAL

ITEM LOCATION

1. Barge-mounted, High-Volurn?, Open Sea Skiaaeer System (HOSS)

2. Fast Response, Skid-Mounted, Skiaaeer System

3. Shallow Water Skiaaeer, CGA-50

4. Shallow Water Skiaaeer, CCA-51

5. *hal low Water Skiaaeer, CCA-52

6. 50 bbl. O i l Storage Barge

7. 36" Bennett or Uniroyal Boom per 100' w/Baaker & Anchor Systt

8. Mioi Fast Response, Skid-Mounted, Skimmer System (for ftandby on platforms and d r i l l i n g vessels) (whether akiaaaicg or not) SEE NOTE

9. Classroom Training Building

10. Saucer Type Skiaaeer

11. 200 GPM C e n t r i f u g a l , Portable Oieael Pump, 3"

12. 100 GPM Air Diaphragm Pump, 2'

13. Hel icopter Sprayer System

14. Bird Scarers - Set of 24

Grand Iale

Venice, Caneron, Intracoaatal City, Rockport, Houma Gelveaton

Venice

Grand Iale

Houaa

Venice, Grand I s l e , Intracoastal City

Venice, Grand Iale, Intracoaatal City, Galveatcn, Rockport

Venice, Grand Isle Intracoaatal City, Caseron

Grand Iale

Venice, Grand Isl e , Intracoaatal City

Venice, Grand Isl e , Intracoaatal City

Venice, Grand Iale, Intracoaatal City

Grand Isle, Intracoastal City, Rockport, Galveaton

Venice, Grand Iale, Intracoastal City

15. Bird Scarera - Set of 12 Rockport, Galveaton

Table 3

16. Waterfowl Rehabilitation Station Grand Isle w/20kw Generator & 1500 gal tank

17. 20kw Generator Skid

18. Sorbent Recovery System, Wringer w/Coapresaor Skida

19. Drua Tranaport Skid, Helicopter L i f t

20. Sorbent Disposal System Incinerator, w/Co-npressor, Compactor, and Generator

21. 175 CFM Air Compressor

22. 40 CFM Air Compressor

23. Hand Skimmers, two sets of 5, w,Manifold and Hoses

24. Boat Sprayer System

25. Sorbent Pads (7 or 10 bales per location)

26. Radio System (does not include Communication Servicea installation charges)

27. 72" Bennett Boom - 1000 f t . (on pallets)

28. Hoses, Asaorted

29. Chemical - Collectant

30. Chemical - Dispersant

31. Dipsersant, 500 gal Tank, two per set

32. Fast Response System, Auxiliary Tank only, 4" connections

Grand Isle

Intracoastal City, Venice, Grand Isle

Venice, Grand Isle, Intracoastal City

Grand Isle

Grand Isle

Venice, Grand Isle, Intracoastal City

Intracoastal City Venice, Grand Isle, Rockport, Galveston

Rockport and Galveston

Grand Isle, Venice, Intracoastal Ci*,, Rockport, Galveston

New Orleans (Gretna)

In t r a o a t a l City

Grand Isle, Veni.e, Intracoastal City, Cameron, Houma

Grand Isle, Venice, Intracoastal City, Rockport, Galveston

Galveston, Rockport

Galvestou, Rockport

Venice, Grand Isle, Intracoastal City, Cameron, Houma, Rockport, Galvestou

Table 4

DRILLING MUD COMPONENTS

Common Chemical or Chemical Trade Name

Aluminum Stearate " A X T A F L O - S " Ba r i t e Calcium Carbonate Calcium Chlor ide Calcium Oxide Calcium Sulfate Carbcxymethy l Cellulose Caust ic Potash Caust ic Soda Chrome Ligni te Chrome Lignosul fonate D r i l l i n g Detergent " E - P a l " Ferrochrome Lignosul fonate Gel

Gypsum L ign i te L ignosul fonate "Muo Sweep" "MOR-REX" " S h a l e - T r o l " Sapp Soda Aah Sodium Bicarbonate Sodium Carboxymethy l Cellulose Sodium Chlor ide Sodium Chromate S ta rch "TX -9010 " " T O R Q - T r i m " "B lack Magic" "B lack Magic Supermix" Diesel " Je l f l eke " MICA "P ipe -Lax " "Wa l l -Nu t " Wood Fibers

Descr ipt ion of Material

Aluminum Stearate Non ion iw Sur factant Barium Sulfate (BaSo4) Aragoni te (CaCo3) Hydroph i l i te (CaCi2) Lime (Qu i ck ) A n h y d r i t e (CaS04) Carboxymethy l Cellulose Potassium Hydrate Sodium Hydrox ide (NaOH) Chrome L ign i te Chrome Lignosulfonate Soap Non- tox ic , biodegradable defoamer Der ived f rom wood pulp Sodium montmori l loni te, benton i te , a t tapu lg i te CaSO4.2H20 Ligni te Lignosul fonate Cement Pre- f lush Hydro lyzed Cereal solid Organo-aluminum complex Sodium Acid Pyrophosphate Sodium Carbonate NaHC03 Sodium Carboxymethy l Cellulose NaCI NaCr04. 10H20 Corn Starch Biodegradable d r i l l i ng lubr icant Biodegradable d r i l l i ng lubr icant Oil base mud cone. Sacked concentrated oil base mud Used to mix cer ta in loss-c i rculat ion p i l ls Plastic f o i l , shredded cellophane Loss-c i rcu lat ion material Sur factant mixed wi th diesel Ground walnut shells Loss-c i rcu la t ion material

Table 5

ZAPATA NEPTUNE MG 39

Typical Well - Garden tanka Block 177

OVERBOARD DISCHARGE

I . CONTINUOUS

A. Salt water cooling - 2 pumps X 570 GPM 1,140 GPM

B. Shale Shaker Ditch / S l ip Joint (aalt water) 310 GPM

C. A.C. Cooling (aa l t water) 130 CPM

TOTAL CONTINUOUS 1.580 CPM

I I . INTERMITTENT

A. Sal t water cooling, 3r1 pump i s run an average of 3 houra a day at 570 GPM

B. Bal las t water ( sa l t water)

1. Dally ba l las t ing avg. 4 co 6 hours at 1760 GPM

2. De-ballast ing 4 bal last ing up ( r ig move) 4 hours each way with 4 pumps at 1760 or 7040 CPM

3. Anchor wench cooling (while running and pull ing anchou approx 14 hours) 2 pumps at 1,760 CPM or 3,520 BPM

C. Treated Waste

1. Waste that has been chlorinated and incinerated. Average waste discharge i s 1 gallon/man/day. Manpower on r ig averagea from 100 to 120.

I I I . MAXIMUM DAILY DISCHARGE

A. During r i g move

1. Salt water Tooling 3 X 570 GPM 1,710 GPM

2. A .C. Cooling 130 GPM

3. Bal las t water

De-Ballast / Bal las t up 4 hours at 7040 GPM Anchor wench cooling 14 hours at 3,520 GPM

4. Treated Waste - 120 gallons par day

Table 6

B. Du-in", normal opera; leaf***-" ^

1. Salt watar cooling 3 X 570 CPM

2. Shale shaker ditch / slip joint

!. A.C. Cooling

4. Ba l l a s t waters 12 hours at 1760 CPM

5. Treated Waste - 120 ga l lons per day

1,710 GPM

310 GPM

130 CPM

DRILLING SOLIDS DISCHARGE

(Based on Diamond Shamrock D r i l l i n g Prognosis f o r Garden Banks Block 177, OCS-G-6355 <U)

30 Inch ( j e t t e d re turns to s« a f l o o r ) Mudline to 250 BML

26 inch ( re turned to sea f l o o r )

221 BBLS 1.241 CU FT

250' BW to 1,000' BML 492 BBLS 2,765 CU FT

17'j Inch 1,000' BML to 2,800' BML 535 BBLS 3,007 CU FT

Inch 2,800 ' BML to 5,900' BML 452 BBLS 2,537 CU FT

th Inch 5,900' BML to 7,200' BML 92 BBLS 513 CU FT

inch 7,z00' BML Co 8,500' BML 54 BBLS 300 CU FT

TOTAL 1 ,84b BBLS 10,363 CU FT

Table 6

ENVIRONMENTAL 7EPOKT

"OP COASTAL MANAGEMENT CONSISTENCY DETERMINATION

PLAN OF EXPLORATION ANO

AIR QUALITY REVIE ' REPORT

GULF OF MEXICO

FOR

GARDEN BANKS AREA BLOCK 177 (OCS-G-6355)

SUBMiTTEO TO: RODNEY S7SFS, JR.

DIVISION DRILLING COORDINATOR DIAMONO SHAMROCK EXPLORATION COMPANY

5333 WESTHEIMFR, SUITE 200 HOUSTON. TEXAS 77056

(713/960-1351)

AUGUST 1985

Pre J red by: JOHN E. CHANCE i ASSOCIATES. INC.

Regulatory 8 Environmental Division Project #85-8208

John C Chance A Assoc., inc.

Table of Contents

ENVIRONMENTAL REPORT

Page

I . m i t Page

Table of Contents 1

List of Figures

List of Tablet

I I . Description of the Proposed Action

A. Travel Modes, Routes, and Frequencies

B. Support Base and New Personnel

C. New Support Fac i l i t i es

D. New or Uftutu2l Tecnnology

E.

I I I . Desc

A.

oc ation of the Proposed Act iv i t ies

Ipt lon of th t Affected Environment and Impacts

Physical and Environmental

Commercial Fishing

Shipping

Recreation

Cultural Resources

Ecologically Sensitive Features

Existing Pipelines and Cables

Other Mineral Uses

John £. Chanco af Assoc.. mo. i i

8 . Ocean Damping 15

9. Endangered or Threatened Species 16

B. Socio-Economic Impacts 17

IV. Unavoidable Adverse Iapacts 18

V. Literature Cited 22

Appendix l—Coastal Zone Management Consistency

Cert i f icat ion 24

AIR QUALITY REVIEW

t . Ti t le Page 26

I . General Information 27

I I . Findings of A1r Quality Review 27

I I I . Total Emissions at Rig/Platform 27

IV. Total Supply 8 Craw Boat Emissions 27

V. Total Helicopter Emissions 28

VI . Transportation Services Oata 28

V I I . Factors Used 1n Calculations 29

VIII. Methodology 29

IX. References 29

John E. Chance at Assoc., inc. H i

LIST OF FIGURES

FIGURE Page

1—V lolty Nap of Gardtn Banks Area Block 177 2

Iv

LIST Of TABLES

TABLE ?«9t

1— COMtrclally Important Shellfish of tne

Gulf of *tx1co 3

2— -Chock List of CQflMfCfai * &or\ nsnts

of Tht Horthtrn Gulf cf Hexlco 11

v

I I . Description of osed Action

This report addresses the act iv i ty proposed by Diamond Shamrock

Exploration Company for Garden Banks Are- 31ock 177 (OCS-G-6355). Tht

approximate location of t<ie ac t iv i ty is presented 1n Figure 1 , a general

v ic in i t y map of the Outc- Continental She! f (OCS) lease areas o f f the c c s t

i f Louisiana.

I t 1s anticipated that ->em1-suDmersible r ig w i l l be moved on location

and f ive exploratory wells w i l l be d r i l l e d . The su-face locations for the

proposed wells and addit ional Information regarding the specific ac t i v i t i es

proposed by Diamond ShamrocK Exploration Comptny for this olock are includec

1n the attached P?an of Exploration.

The proposed ac t i v i t i e s w i l l be carr ied out by diamond Shamrock

Exploration Company with a guarantee cf the fol lowing:

1. The best avai lable and safest technologies w i l l be u t i l i zed

throughout the project . This Includes meeting a l l applicable

requirements for equipment types, general project layout, safety

systems, equipment and monitoring systems.

2. All operations w i l l be covered by M.M.S. approved Oil Spi l l

Contingency Plan.

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

air emissions, water qual i ty, and discharge for the proposed

a c t i v i t i e s , as well as any other permit conditions, w i l l bt

John £ Chanco at Assoc., Inc. l

compl ied wi th .

A. Travel Modes, Routes, and Frequencies

Diamond Shamrock Exploration Conpany w i l l operate out of thei r service

base f a c i l i t i e s established in Cameron, Louisiana. Diamond Shamrock

Exploration Company anticipates using one hel icopter, one work boat and one

crew boat to support the i r Garden Banks Area Block 177 exploration a c t i v i t y .

The helicopter w i l l travel to the location a total of two times per week.

The crew boat ana work boat w i l l t r^vci ta tne location a total of seven

times per week eacn.

I t '% anticipated that the transportation vessels w i l l u t i l i z e the most

d i rec t route from the Cameron, Louisiana service base. Because • vessel

supporting the Garden Banks Area Block 177 exploration ac t i v i t i es ma> be

scheduled for other stop in the area, the exact route for each vessel on

each part icular t r i p cannot be predetermined.

B. Support Base and New Personnel

Diamond Shamrock Exploration Company w i l l u t i l i z e support base

f a c i l i t i e s establi ?d In Cameron, Louisiana. Cameron, Lou**1ana 1s located

approximately one hundred for ty- four miles from the ac t i v i t y s i t e .

Because helicopter and marine f a c i l i t i e s are currently available at the

service base and are presently and continuously manned, no additional

John £ Chance 4% Ammoo* mo. 3

onshore employment Is expected to be generated as a result of these

a c t i v i t i e s .

The i n i t i a l OCS Soclo-Economic Oata Base Report for the service base

f a c i l i t i e s u t i l i zed by Diamond Shamrock Exploration Company w i l l be prepared

for submission pursuant to the specific parameters to be established by tne

DOI/MMS and scheduled to be Issued at a later date.

C. New Support Fac i l i t i es

The proposed exploration ac t i v i t ies for Garoen Banxs Area Block 177

w i l l not require the development of any new support f a c i l i t i e s .

0. New or Unus»al Technology

The exploration a c t i v i t i e s for Garden Banks Area Block 177 w i l l net

warrant u t i l i z i ng any new or unusual technology that may affect coastal

waters.

E. Location of the Proposed Act iv i t ies

Garden Bank Area Block 177 Is located approximately one hundred

fo r t y - fou r miles from the Cameron, Louisiana support base and one hundred

forty-two miles from the Louisiana coast of Cameron Parish. Figure 1

presents the location of the block in relat ion to the Louisiana coast, as

well as the geographic relat ionship between Garden Banks Area Block 177 and

the other OCS lease areas.

John C Chance at Assoc., inc. 4

I I I . DESCRIPTION OF THE AFFECTED ENVIRONMENT ANO IMPACTS

A. Physical and Environmental

1. Commercial Fishing

Commercial f ishing has t rad i t iona l ly provided an important economic

base for a majority of the coastal communities along ths Gulf of Mexico. In

1982, the Gulf coastal states landed 2.3 b i l l i o n pounds of f ish products

representing a th i rd of the nation's t o t a l , valued at over 600 mi l l ion

do l la rs . The f ive commercial f isheries of the greatest economic Importance

are the shrimp, mennaden, oyster, industr ial bottom f i sh , and crab

f isher ies .

In 1982, Gulf fishermen landed cve» 209.9 mil 1 ion pounds of shrimp

representing 75 percent of the nation's total and valued at over 425 mi l l ion

do l la rs . The northern Gulf shrimp fishery 1s comprised mainly of three

species; the brown shrimp (Penaeus aztecus). the white shrimp (P. set i ferus)

and the pink shrimp (p. duorarum). The smaller brown shrimp represent

approximately 60 percent of the shrimp taken, the pink shrimp 10 percent,

and the white shrimp account for a majority of the remainder. Three other

species, the rock shrimp, royal reds, and the seabobs, are also taken

commercially In the northern Gulf but together comprise less than 4 percent

of the total shrimp landings.

V John E. Chance at Ammoo* Inc. 5

Preliminary stat ist ics compiled by the National Marine Fisheries

Service Indicate that 76,953,758 pounds of shrimp (heads on) valued at over

130 million dollars were landed at Louisiana ports In 1983. It should be

noted that catch stat ist ics are recorded by the area landed and do not

necessarily Indicate that the species were actually caugnt In waters

adjacent to the ports where they were landt**

Most shrimp ars taken by trawl and are estuarine dependent In that they

require estuaries during some stage of their Hfe cycles. Mature shrimp

leave the estuary for tne open Gulf where they spawn (release eggs). The

eggs and subsequent larval stages circulate freely 1n the currents of the

OCS and can be found 1n virtually al l OCS waters. Young Juvenilis then

enter the estuary to feed, mature, and repeat the cycle.

The proposed petroleum activit ies in Garden Banks Area Block 177 are

expected to have no impact on the harvest of brown or white shrimp since

Garden Banks Area Block 177 Is beyond the outer limits of the harvest area

for these species. (U.S.D.I. FREIS, Gulf of Mexico 1983 Visual No. 4-1.)

The Gulf oyster fishery provided over 40 percent of the oysters landed

nationally In 1982 totaling 24.2 million pounds of meat worth over 33

million dollars. Most Gulf oysters are taken by oyster dredging in

estuarine and coastal waters within 5 miles of shore. According to National

Marine Fisheries Service stat is t ics over 13 million pounds of oysters valued

at over 17 million dollars were landed at Louisiana ports In 1983. Tht

r

proposed ac t iv i t ies in Garden Banks j r e * 91ock 177 are not expected to have

any Impact on tht oyster fishery in Louisiana.

In 1981 the Gulf States also 1anded 37.4 n m i o n pounds of blue crabs

(Calllnectes sapidjsi valued at over 8 n i l l i o n dol lars, '•ost vere -.aot-red

in "pots" (baited tr»os) in snailow estuarine or tear :nore waters. 31ue

crabs are also cauqnt using " t ro t l ines" snal lo*. imiltlbel ted l ines) and

bottoa trawls. *hese :-aos are estuarine ieoe"de*t - i t * pia"»t3«i: - v ; ;s and

larval stages. Blue crao landings at .ouisiana sorts totaled over ' i

m i l l ion pounds valued at over 16 mil Hon dollars in 1983, according to

National Marine Fisheries Service Sta t is t ics . Ttoe ' i s * e - / for 11 j i : ra js

w i l l not be affected by e*oloration and production ac t i v i t ies In tnt te

Dlocks as i t is offshore of tne coastal a«d est^a»-«ne eaten aftlCh t a l l

f ishery operates.

Table 1 presents a 11st of commercially important sne l l f i s * found in

the northern Gulf of Mexico.

The menhaden or "Pogy" fishery 1s the nation's second most valuaDle

f ishery accounting for 1.2 b i l l i o n pounds valued at 47 mi l l ion dollars or

roughly half of the tota l 1981 f ish poundage landed in the u. S. Spurred by

a 55 percent Increase In aenhaden landings from the Gulf coast states, the

U. S. had a record sett ing aenhaden catch in 1982. Gulf landings were 1.9

b i l l i o n pounds worth over 72 mi l l ion do l la rs . Four species are said to

comprise the aenhaden fishery but the Gulf menhaden (Brevoortia patronus)

accounts for aost of the e t c h . Menhaden are processed Into f i sh aeal , f i sh

7

'ABLE I COMMERCIAL IMPORTANT SHElLflSH

ME jJL? Of MEXICO

COMMON NAME

SHRIMP:

Brown Shrimp

White Shrimo

P1nk Snrlmp

SeaboD

Royal Red Snrimp

Rock Shrimp

SCIENTIFIC NAME

2?j?ieus ijttecut

P_. l e t i Penis

<1;ioo*njeus <rayerl

ij iv»no_3«jiaeus r-jpus'.j'.

S<:yon1a brevirostrJs

-ARVEST "ETH00

IT

•* BT

Blue Crab Cail ir.ectes sapidus :T.BT. '

Oysters Crassostrea sp. OO.O'

BT Bottom Trawl

CT Baited Crab Trap

00 Oyster Dredge

OT Oyster Tongs

TL "Trot l ine"

John C Chmnco at Anmoa* mo. 8

o i l , and f ish solubles for Industr ial use. Menhaden are estuarine dependent

with planktonic eggs. Garden Bancs Area 81oc« 177 Hes beyond the

"Principal Menhaden Harvest Area" (U.S.D.I . , rREIS, Gulf of Mexico 1383,

Visual Mo. * - I ) . therefore negative imoacrs on •nennaden f ishing are

unl ikely.

Industrial oottomf 1 sn«s Td*e ip J * arge r^ne*-/ t*e ,. *. «itn:n

th is group are fishes taken on or vary nea^ tne ootto* ay : u rc ia l

trawlers. The following fishes general 1* account *or >5 *o )G .^e^cent of

the Industrial oottoufisn trawl f ishery: .^axe ' - . :oot. sand seatrout,

s i lver seatrout, c a t f i s h , and iong.so<ne oorgy ( . .S .D. I . . 19831.

Many of the species ta<en in tne industrial Boctomflsn citegory spawn

in offshore waters, and i t is possible, tnat tne eggs might Oe adversely

affected oy contact witn d r i l l Cuttings ana/or d r i l l i ng mud i f tney mere

present near the r ig during such releases. These discharges may also cause

temporary relocation of adults due to Inundation of feeding ground at the

d r i l l s i te . Fishing ac t i v i t y w i l l be temporarily interrupted by the

placement of the d r i l l i n g r ig but no long-term effects are anticipated as a

resul t of this proposal. IndustMal bottomfish are usually sold as

Industr ial fishmeal and f i sh solubles, but th is group also produces some

foodf lsh, pet food, and FPC ( f ish protein concentrate).

Other spedes for which s igni f icant commerc al f isheries exist Include

str iped mullet, groupers, snappers, and flounders. Mullet are taken near

shore and 1n estuarine waters in seine nets, g i l l net'., »nd cast nets.

%9ahn E. Chanco at Ammoc, mo. 9

r Snappers and growpars art taken by hook and 1Ine throughout the OCS wherever

naturally occurring or man-made benthic features provide sufficient habitat.

Flounders are also caught commercially by hook and line and are taken

seasonally tn very shallow estuarine water by gig [fcrrMets spear).

Weakfishes, croakers, and drums are also taken commercially by nook and line

as foodflshes. Table 2 presents a l i s t of commercially important industrial

bottoaflshes and sport fishes found in tne Gulf of Mexico.

Overall, commercial fishermen nave oenefitea *rom the growth jf tne

petroleum Industry in the OCS water af the Gulf of Menico Sthile

technological Improvements have enabled commercial fishermen to increase tne

volume of landings, development of the petroleum <*dustry has also had a

positive Impact on fishing. Because OCS petroleum development is dependent

on extensive marine vessel uti l ization, harbors and ports have been

Improved, port access waterways have o?en expanded and improved, and the

availability and quality of marine vessel maintenance and repair fac i l i t ies

have Increased significantly. These Improvements have definitely had a

positive effect on fishermen ( lasslter , i960).

2. Shipping

A designated shipping fairway Is located In the southern portion of

Garden tanks Area Block 177. Diamond Shamrock's proposed exploratory

act iv i t ies will not be loceted within this shipping fairway. It 1s unlikely

that the shipping fairway located In the southern portion of the hlock will

be used to gain access tc the support base, therefore, i t 1s unlikely thet

10

TABLE 2

A CHECK LIST OF COMMERCIAL i SPORT FISHES

OF THC NORTHERN GULF OF MEXICO1

COMMON NAME SCIENTIFIC NAME"

Gulf Menhaden 2revcortii Mtronus

Hardhead Catflsn Arlus f t l i s

Gafftopsail Catfish 3agre .aarinus

Warsaw Grouper Eoinep! lus nigritus

Jewfish Epineoneljs Itajara

Red Grouper Epinephelus aorio

Rock Hind Epinephelus adscenslonis

Florida Poapano Trachino*.us carollnus

Red Snapper LutJanus caapechanus

Sheepshead Archosargus probetocephalus

Northern Klngflsh Mentlc rhus saxatlHs

Black Drua Pogonias croais

Atlantic Croaker Mlcropogonlas undulatus

Spotted Seatrout Cynoscion nebulosus

Sand Seatrout Cynoscion arenerius

Red Drua Sciaenops ocellatus

Spot Lelostoaus xan thurus

Striped Mullet Mugil cephalus

King Mackerel Scoaberoaorus cavalla

TABLE 2 (cont'd)

A CHECK LIST OF COMMERCIAL * SPORT FISHES

OF THE NORTHERN GULF OF MEXICO

Spanish Mackerel Scoubcrc-norus maculatus

Unclassified Flounders Paralichthys spp.

1. Based on landing s ta t i s t i c s compiled by the National Marine

Fisheries Service, New Orleans, Louisiana.

2. Scient i f ic nomenclature Vom American Fisheries Society (1980)

John E. Chance at Aaaoo* mo.

12

the leerlne vessels n i l ! have en s igni f icant e f fec t on falrwey t r e f f l c . The

d r i l l i n g r ig and eech of the merl.ie vessels w i l l be equipped with a l l U. S.

Coast Guard required navigational saftty a i d ' .

3. Recreation

The open Gulf encompasses a broad expanse of saltwater which Is

u t i l i z e d by numerous sports flsnenten and a smell but rapidly Increasing

number of SCUBA 11 vers. Many fishermen i ter ter boats to deep-sea f ish and

sport dive 1n the northern Gulf. The states j f Alabama, Mississippi, and

Louisiana support approximately 120 charter boats which conduct a majority

of the i r fishing a c t i v i t i e s in the waters of the OCS (U.S.D.I . . 1983).

Petroleum platforms In the northern Gulf provide recreation for fishermen

and scube divers because they act as a r t i f i c i a l reefs attract ing and

establishing aquatic communities including highly sought af ter food and

sport f ishes. The reef e f fec t created by petroleum platforms Is well known

and 1s evidenced by the numerous private boat owners who regularly v i s i t

offshore f a c i l i t i e s to harvest food and sport f ishes.

Frequently, offshore r igs and platforms serve es navigation points for

smell commercial and recreational marine c r a f t . Manned d r i l l i n g r igs end

platforms can also provide a haven for small c r a f t operators forced to

abandon their vessels during storms or following boat accidents. The

Ins ta l la t ion and use of navigational alus, l l fesevlng equipment, and other

sefety requirements pursuant to Coast Guard regulations are standard

procedure for d r i l l i n g r igs and marine vessels u t i l i zed by Diamond Shamrock

John E. Chance at Ammoo* mo. 13

Exp lo ra t i on Company.

4. Cultural Resources

Visual lo . i l from tne Regional Environmental Impact Statement

(U.S.D.I , 1983) Indicates that Garden Banks Area Block 177 fa l l s beyond the

zones designated as areas with high probabi l i t ies of h is tor ical or

pre-h1stor1cal cultural resources, therefore there w i l l be no s igni f icant

Impact on any cu l tura l ly s ign i f icant feature.

5. Ecologically Sensitive Features

The northern portion of 31ocx 177 f a l l s within tht designated zone of

the West Flowtr Gardtns. Diamond Shamrock Exploration Company's planned

ac t i v i t i es do nc: f a l l wi th in th is designated area. There are several

ecologically sensitive artas ntar Garden Banks Area Block 177, however,

Diamond Shamorck's planned act t ics w i l l not neve any s ign i f icant Impacts

upon any ecologically s ign i f icant features.

Cameron, Louisiana w i l l be u t i l i zed as the operations base for ilurdtn

Banks Area Block 177. Cameron, Louisiana 1s located approximetely four

miles from the Rutherford State Refuge (U.S.D.I. Wi ld l i fe Refuge, FREIS.

Gulf of Mexico, 1983, Visual No. 3) .

in general I f a l l a c t i v i t i e s a-e executed as planned, encountering no

unusual circumstances, the envIre"Mentally sensitive areas w i l l not be

John E. Chanco at AKBOO* Inc. 14

af fected.

6. Exit Ing Pipelines and Cables

The snallow hazards survey performed for Diamond Shamrock Exploration

Company and Included as an attachment to the Plan of Exploration Indicates

two large seafloor depressions are present within the block, Numerous

smaller seafloor depressions or pockmarks are scattered throughout the

t r a c t . These features are common 1n the Gulf of Mexico and are usually

caused by sponuneous venting of biogenic gas and/or i n t e r s t i t i a l water

during normal compaction. Several water column anomalies wero also noted in

the data and are probably caused by dense concentrations of nektonlc

organisms. No magnetic anomalies were detected. Diamond Shamrock

Exploration Company is aware of the potential hazards and has taken the

necessary precautionary measures.

There are nc known n.an-ir.ade features 1n the lease area.

7. Mineral Resources

There are no other known mineral resources located In or near Garden

Banks Area Block 177.

8. Ocean Dumping

The major sources of ocean dumping related to OCS petroleum exploration

John E. Chanco at Assoc., Inc. 15

ac t i v i t y are d r i l l i n g f l u i d s , or "muds," and d r i l l cut t lnys. After the

exploratory d r i l l i n g 1n Garden Banks Area 31ock 177 1s complete. Diamond

Shamrock Exploration Company does anticipate dumping thei r excess

water-based d r i l l i n g f lu ids (approximately 1400 bbls) . I f any oil-based mud

1s used during the d r i l l i n g operations, 1t w i l l be returned to the /endor

for proper disposal at an approvea s i te .

D r i l l cuttings are brought up by the d r i l l i n g mud and range 1n size

from grains of sand to pebbles. These cutt ings are separated and s i f ted and

then disposed overooard. Treated domestic wastes and d r i l l waters w i l l also

be disposed at the proposed d r i l l i n g s i te . There w i l l be no Intentional

discharge of any o i ly or hazardous materials In v io lat ion of DOI or EPA

regulat ions.

Garden Banks Area Block 177 1s not located within an approved mi l i ta ry

ordinance area or an approved dumping s i te .

9. Endangered or Threatened Species

Endangered or threatened species which might occur In the Garden Banks

Area are blue whale (Balaenoptera musculus), finback whale (Balaenoptera

physalus), humpback whale (Megaptera novaeangliae), se1 whale (9alaenoptera

boreal I s ) , sperm whale (Physeter catodon), Kemp's r idley t u r t l e

(Lepidochelys kempi 1 ) , green t u r t l e (Chelonia mydas). hawksbill t u r t l e

(Eretmochelys Imbricata). leatherback tu r t l e (Dermochelys coriacea) and

loggerhead t u r t l e (Caretta caretta) (U.S.D.I . , Region IV Endangered Species

J o h n MZ. C h a n c o I J S O C . I n c . 16

Notebook).

Endangered and threatened species expected to occur in the v ic in i t y of

the onshore bese are bald eagle (Hallaeetus leucocephalus), the brown

pelican (Pel ec anus occldenta l is) , and American a l l igator (Al l igator

m1ss1ss1pp1ens1s) (U.S.D. I . , Region !V Endangered Specie Notaoook). Tne

brown pelican was a common resident of Louisiana but th is species became

v i r t u a l l y ext inct in tne la te 1950 s i F r l t t s et a l . , 1983). By I960, the

estimated Louisiana population of brown pelicans was four olrds (NFWL,

1980). Re-estaol ithment of 3 breeding population 1n Louisiana has met with

varying succ:ss (F r i t t s et a l . , 1983). The ac t i v i t ies proposed by Diamond

Shamrock Exploration Compeny are expected to nave no Impacts on the orown

pel ican. The American a l l i ga to r Is c lass i f ied as threatened bio logical ly 1n

Louisiana and a regulated harvest 1s permitted under State law ( J .S .D . I . ,

Region IV Endangered Species Notebook). No impacts on American a l l igators

er" expected. The presence of marine mammals 1n coastal Louisiana Is

considered sporadic and probably no resident populations ex is t . I t Is

unl ikely that onshore or exploration ac t i v i t i es related to Garden Banks Area

w i l l have any ef fect on thc previously named species.

B. Socio-Economic Impacts

In accordence with DOI/MMS guidelines (OS-7-91), dated November 20,

1980, the I n i t i a l OCS Oata Base Report w i l l be developed for submission on

or before the prescribed due date. Subsequent Environmental Reports

provided by Diamond Shamrock Exploration Compeny w i l l address th is data and

related ac t i v i t y impacts as required.

John E. Chanco 4fc Ammoo., Ino. 17

IV. UNAVOIDABLE ADVERSE IMPACTS

The greatest threat to the natural environment 1s caused by Inadequate

operational safeguards that may cause or contH. :ta to an o i l sp i l l or well

blowout. These accidents can be greatly reduced 1n number b> u t i l i z i ng

t ra i red operational - -sonnel and employing a l l availaole safety and

pol lut ion control systems. These measures are standard operating procedure

for Diamond Shamrock Exploration Company. Oianond Snamrocx Exploration

Company nas an approved 011 Spil l Contingency Plan.

I t should be noted that nost large crude o i l and refined products

s p i l l s have occurred during transportation and not during d r i l l i n g or

production operations. Furthermore, the probabi l i ty of an o i l sp i l l

occurring during exploratory d r i l l i n g operations is low (Danenberger, 1976).

Transportation and r iver runoff contribute an estimated 34.9 percent and

26.2 percent, respectively, to the hydrocarbon contamination of the world's

oceans while offshore production ac t i v i t i es account for only 1.3 percent

(National Academy of Sciences, 1975). Natural seeps of petroleum and

natural gas, which occur throughout the northern Gulf of Mexico (Zo Be l l ,

1954; Geyer, 1979), contr ibute an estimated 9.8 percent to the contamination

of the world's oceans (National Academy of Sciences, 1975). Addit ional ly,

1t was noted In the executive summary of a recent study of petroleum

production platforms In the central Gulf or Mexico (^d inger , 1981), that

natural disturbances ( I . e . r iver flooding and storms) can more greatly

a f fect nornol biological communities than the current Industrial development

>f the Louisiana OCS. The preceding discussion 1s not intended to minimize

John E. Chance at Assoc., inc.

13

the significance of major o i l sp i l l s result ing from petroleum exploration

and production ac t i v i t i e s but is provided to estaolish a perspecti"-

relat ive to their probable occurrence.

Thirteen of the fo r ty -s ix blow-outs on the OCS between 1971 and 1978

were associated witn exploratory d r i l l i n g a c t i v i t i e s , none of which released

any oi l to the marine environment (Danenoerger, 1980). The IXTOC I sp i l l of

1979, however, demonstrates that advanced d r i l l i n g technology and availaole

safety and pol lut ion control systems are not i n f a l l i b l e . Most sp i l l s are

subjected to immediate containment and cleanup e f fo r t s . The ultimate fate

of o i l spi l led in the marine environment is generally considered to be one

or a comoination of tne fol lowing: evaporation and decomposition in the

atmospnere, dispersal 1n the water column, incorporation into sediments, and

oxidation by chemical or biological means (National Academy of Sciences,

1975).

The unavoidable adverse impacts that w i l l occur as a resul t of the

exploratory d r i l l i n g and discharging of d r i l l i n g f lu ids <ind treated sewage

w i l l be few 1n number and temporary In nature. The primary adverse Impacts

include a localized degradation of water and air quality In the v i c in i t y of

the d r i l l i ng s i t e , the potential obstruction to commercial and recreational

f1»h<ng vessels, and the disruption and/or k i l l i n g of benthic and/or pelagic

organisms during location of the d r i l l i n g r ig and during disposal of muds,

cu t t ings , and domestic wastes and sewage.

John .C Chance 4% Assoc* Inc. 19

Discharging from the d r i l l s i te 1s inevitable during OCS operations,

par t icu lar ly during explorat ion. Any materials that may contain o i l or

other hazardous materials, and therefore would have a much greater adverse

Impact on the environment, w i l l not be discharged 'n tont ional ly . Any

discharging w i l l be done pursuant to a l l DOI and E?A regulations. Thr

discharges to be disposed overboard as a result of the exploration ac t i v i t y

w i l l Include domestic waste and sewage tnat 1s treated on the r ig before

discharging and d r i l l cutt ings and mud.

The environmental f a t . and effects of d r i l l i ng muds and cutt ings has

been extensively addressed in a recent symposium (Se? V « r s et a l . , 1980 for

detai led discussions). The discharging r f d r i l l cuttlnos and water-based

raud w i l l result 1n an increase in water t u r c i d l t y , burial of benthic

organisms, and possible toxic effects on marine organisms in the immediate

v i c i n i t y of the d r i l l i n g r i g . A reduction 1n photosyntnetlc ac t iv i ty and

plankton populations can also be expected as a result of discharging. I t 1s

expected, however, that oelaglc and benthic organisms w i l l repopulate the

area rapidly after discharging 1f the effects are minimal and Intermit tent

as expected.

Offshore ac t i v i t i es generate a small but s igni f icant amount of a i r

pol lutants; therefore, the deterioration of a i r quality 1s unavoidable 1n an

OCS operation area. In most Instances, these emissions affect only the

Immediate exploration ac t i v i t y s i te and are rapidly dissipated by the

atmosphere depending upon cl imatic condit ions. An Air Quality Review Report

has been performed for Gar'et; ^-ea Block 177 and is included as an

— John £. Chance at Assoc.. Inc. 20

attachment to the Environmental Report.

Commercial end recreational fishing would oe affected by OCS

development, but primarily 1n terms of Inconvenience and Interference.

Although the unavoidable adverse Impects could include some smothering of

shel l f ish, snagging of trawl nets, reduction of area presently used for

unrestricted fisning, and minimal finfish k i l l ing , commercial fishing

activit ies would not be significantly effected, except In ;ne unlikely event

of an oil s p i l l . An oil spi l l could result in serious economic losses due

to the contamination of commercial fish species.

There is a remote possibility that offshore areas of historical ,

cult- a l , or biological significance could be damaged or destroyed by OCS

e ation operations. Visual No. 11 from the Regional Environmental

ict Statement (U.S.D.I . . 1983) Indicates thet no archeological, cultural ,

i historic arees ere In tht vicinity of Garden Banks Arte.

Diamond Shamrock Exploration Compeny will make every effort to avoid

disturbing any historical ly, culturally, or biologically significant

fee ture.

»*cjmVt E. CHmnom et Anwoo., mo. 2\

LITERATURE CITED

American Fisheries Society 1980 A List of Common and Scienti f ic Names of Fishes from the United

States and Canada (Fourth Edi t ion). Special Publication No. 12. Bethesda, Maryland. 174 pp.

Ayers, R. C . N. L. Mcherds and J . S. Gould 1980 Proceedings of a symposium. Research on environmental fate

and effects of d r i l l i n g f lu ids and cut t ings. Wasnlngton, D.C. 1,122 pp.

Bedlnger, C. A., Jr . 1981 Ecological ,nvestigat1ons of petroleum production platforms 1n

the centr-1 Gulf or" Mexico. Volume I I I : Executive Summery. Submitted tQ the Bureau of Lano Management, New Orleans, Louisiana. Contract No. AA551-CT9-17. 29 pp.

Danenberger, E. P. 1976 011 s p i l l s . 1971 - 1975, Gulf of Mexico Outer Continental Shelf.

Geological Survey Circular 74'. 47 pp.

Danenoerger, E. P. 1980 Outer Continental Shelf Oil and Gas Blowouts. U.S.U.S. Open-File

Report. 80-101. 15pp.

F r i t t s , T. H., A. B. I rv ine, R. 0. Jennings, L. A. Collura, W. Hoffman, and M. A. McGehee

1983 Turtles, b i rds, and mammals 1n the northern G*.lf of Mexico and nearby Atlantic waters. U. S. Fish and Wi ld l i fe Ser/1c«», Division of Biological Services, Washington, D. C. FWS/0BS-8 765. 455 pp.

Gal laway, B. J . 1981 An ecosystem analysis of o i l and gas development on the Texas-

Louisiana cor.tlnental shelf. U. S. Fish and Wi ld l i fe Service, Office of Biological Services, Washington, D. C. FWS/0BS-81/27. 89 pp.

Gallaway, B. J . and G. S. Lewbel 1982 The ecology of petroleum platforms 1n the northwestern Gu f o; Mexico:

a community p ro f i l e . U. S. Fish and Wi ld l i fe Service, Office of biological Services, Washington, 0. C. FWS/0BS-82/27. Bureau of Land Management, Gulf of Mexico OCS Regional Of f ice, Open-File Report 82-03. XIV +92 pp.

Gallaway, B. J . , L. R. Mart in, R. L. Howard, G. S. Boland, and G. D. Dennis 1981 Effects on a r t i f i c i a l reef and demersal f i sh and macrocrustacean

communities. Pages 237-293 In B. S. Middleditch, ed. Environmental effects of offshore o i l production. The Buccaneer Gas and 011 Field Study. Marine Science, Vol. 14. Plenum Press, New York, New York.

John E. Chance & Assoc.. Inc. 22

Geyer, R. A. 1979 naturally occurring hydrocarbon seeps In che Gulf of Mexico and

Caribbean Sea. College Station, Texas: Texas A a N University Press.

National Academy of Sciences 1975 Petroleum In the marine environment. Washington, D.C 107 pp.

National F1sh and Wi ld l i fe Laboratory (NFWL) 1980 Selected vertebrate endangered spedes of the seacoast of the

United States: 3-own Pelican, eastern and California subspecies. U. S. F1sh and Wi ld l i fe Service, 31o1og1cal Services Program FWS/OBS- 80/01.40. 16 p j .

National Marine Fisheries Service 1984 Louisiana 1 inding s ta t is t ics from je--*onal communication with Lee

USIA. NMFS. New Orleans. La.

U. S. Department of the In te r io r . Flsn i Wi ld l i fe Service 1976 Endangered and threatened spec, s of the southeastern united States.

Region IV, At lanta, Georgia (periodical ly updated).

U. S. Department of the In te r io r , Minerals Management Service 1983 Final Regional Environmental Impact Statement, Gulf of Mexico.

Vol. 1 Prepared by Minerals Management Service, Gulf of Mexico OCS Region, Metair ie. Louisiana. 527 pp.

Zo Se l l , C. E. 1954 Marine bacteria and fungi , Fisheries Bullet in 55 (89): 217 . 222.

John £. Chance al Assoc., inc. 23

APPENDIX 1

COASTAL ZONE MANAGEMENT

CONSISTENCY CERTIFICATE

John E. Chanco 4% Aamoo* Inc. 24

COASTAL ZONE MANAGEMENT

CONSISTENCY CERTIFICATION

EXPLORATION

Type of Plan

GARDEN BANKS ARrA BLOCK 177 (OCS-G-6355)

Area ana Block

The proposed ac t i v i t i e s described 1n detai l in the attached Plan of Exploration comply with Louisiana's approved Coastal Management program and w i l l be conducted 1n a manner consistent with such Program.

Arrangements have been made with the State Times in Baton Rouge, Louisiana to publish a Public Notice of the Proposed ac t iv i ty no la ter than

DIAMOND SHAMROCK EXPLORATION COMPANY

Lessee or Operator

..J/h.bJtt Cert i fy ing Of f ic ia l

Date

John E. Chanco at Assoc., kw. 25

AIR QUALITY REVIEW For

Garden Banks Area Block 177 OCS-G-7719

Diamond Shamrock Exploration Company 5323 Westheimer, Suite 200

Houston, Texas 77056

* * *

Submitted To Rodney Dykes, J r .

Division Dr i l l i ng Coordinator

August 6, 1985

* * *

Prepared by: JOHN E. CHANCE 8 ASSOCIATES, INC.

Regulatory and Environmental Division Lafayette, Louisiana Project No. 85-8208

John £ Chance at Assoc., Inc. 26

PROJECTED AIR EMISSION SCHEDULE FOR EXPLORATION PROJECT

I . General Information

Location of Fac i l i ty - Garden Banks Area Block 177 Name of 71g/P1 atform - Seffi-Submersible Owner/Operator - Diamond Shamrock Exploration Company Address - 3333 Westheimer, Suite 200

Houston, Texas 77056 Contact Person - Rodney Dykes, J r .

Division Dr i l l i ng Coordinjtor Project Start Oate - August 31, 1985 Project End Data - December 31, 19e5 Total Well Footage to be Dr i l led - 42,500 Distance Offshore - 142.0 miles

I I . Findings of Air Quality Review

As per OOI-KMS regulations th is f a c i l i t y is exempt from further a i r quality review as i t has been determined that I t s operation w i l l not have a signi f icant adverse ewlronmental impact on a i r qual i ty .

I I I . Total Emissions at Rig/Platform

Allowable Projected Emission Emitted Emissions Emissions Status Substance tons/yr) (tons/yr) (OK/NG)

CO 92541.7 21.3 OK S02 4728.6 .8 OK NOX 4728.6 147.5 OK VOC 4728.6 7.7 OK TSP 4728.6 .009 OK

IV. Total Supply 4 Crew Boat Emissions at Cameron, Louisiana

Eal t ted Pr o j ec ted Sta tus Substance (s) Emissions (OK/NG)

(tons/yr)

CO 19.3 OK S02 * * NOX 135.6 OX VOC 7.3 OX TSP

• J o h n E . C h a n c o at 4 s s o c , Ano. 27

V. Total Helicopter Emissions at Cameron, Louisiana

Emitted Projected Status Substance (s) Eais. ons (OK/NG)

(tons/yr)

CO .2 OX S02 .006 OX NOX .02 OK VOC .02 OK TSP .009 OK

VI . Transportation Services Data

Supply Boats (3000 hoj

Port - Cameron, Louisiana Welting Time - 24 hrs. :jy Trips Per Week - 7

Crew Boats (2500 hp)

Port - Cameron, Louisiana Welting Time - 1 hrs. Trips Per Week - 7

Helicopters

Bese - Cameron, Louisiana Trips Per Week - 2

Other (Explain) - N/A

*The EPA does not provide S02 and TSP emission factors for boats nor does I t provide TSP factors for d r i l l i n g .

John E. Ghcnom at Ammoo* mo. 23

VI I . Factors Used In Calculations

Emission Factors for Power Generation

Emitted Substance(s)

Onl l ing (Ib/hp-hr)

CO S02 NOX VOC TSP

.0042

.001°

.028

.00095

Emisson Factors for Helicopters and Boats

Emi t ted Substance(s)

Hel 1coot?^s ( l b / e n . .rf-LTO)

Boats I lb /ga l )

CO S02 NOX VOC TSP

5.7 .10 .57 .52 .25

.0598

.1196

.0226

Other Factors P~!l11ng Power Generation - 60 hp-hr / f t Fuel Consumption by Boats - .0959 gal/KW-hr

VI JI . Meu.dology

R1g/Platform - horsepower-hour method Boats - horsepower-hour method Helicopters - landing/takeoff (LTO) cycle method

IX. References

D r i l l i ng -EPA-450/3-7/-026 (June 1977) - "Atmospheric Emissions F'om Offshore 011 Development and Production", pp. 81-92.

Boats and Helicopters - EPA Report AP-42 - "Compilation of Air Pollutant Emission Factors", 3rd ed i t ion, (August 1*77), pp. 116, 125, 127.

* The EPA does not provide S02 and TSP emission factors for boats nor does i t provide TSP emission factors for d r i l l i n g .

— John EL Chant » at Assoc., Inc. 29