I n Reply Refer To: MS 5231 June 13, 1991

Shell Offshore Tnc. Atcentlon: Mr . D. Megil gan Post Office Box 60159 New Orleans, Louisiana 70160-0159

Gentleaen: NOTED - KRAMER

Reference ia made to the fol lowing plan received May 30, 1991:

Type Plan - Supplemental Plan of Exploration Leaae(a) - OCS-G 7963 Block(s) • 807 Area - Mississippi Canyon Act iv i t ies Proposed - Wells I through L

I n accordance wi th 30 CFR 250.33, this plan i s hereby leeaed subaitted and is now being considered for approval.

Your control number i s S-2656 and should be referenced i n your communication and correspondence concerning th i s plan.

Sincerely,

(Orig. Sgd.) A. Donald Giroir

3« D. J. Bourgeois Regional Supervisor Field Operations

bcc: Leasa OCS-G 7963 POD File (MS 5032) 'MS 5034 w/public info, copy of tha plan and accoap. Info.

WWilliamson:cic:6/10/91:Completion Letter

Shell Offshore Inc. An 0tmmm at Sft— Ou C i <v**i

Ona Shall Square P O Box 60159 Naw Orttans. Louisiani 70160

Otepwater Division

MAT 30

Regional Supervisor O f f i c e o f Field Operations Minerals Management Service 1201 Elmwood Park Blvd. New Orleans, LA 70123-2394

Dear S i r :

SUBJECT: BOREHOLE PROJECT SUPPLEMENTAL PLAN Of EXPLORATION SOI OCS-6 7963, MISSISSIPPI CANYON BLOCK 807 OFFSHORE LOUISIANA

Shell Offshore Inc. (SOI) herewith submits * . your approval a Supplemental Plan of Exploration (POE) for vocations I through L in OCS-G 7963, Mississippi Canyon Block 807. The planned wells are being d r i l l e d to acquire information on shallow water sands In the area and no • prospect ive hydrocarbons w i l l be encountered. Your prompt review and approval of this Plan w i l l be great ly appreciated, as d r i l l i n g may commence by June 25, 1991.

This Plan 1s submitted in accordance with 30 CFR 250.30, ef fect ive May 3 1 , 1988, and consists of a series of attachments describing detai ls of our Intended operations. The attachments we desire to be exempted from disclosure under the Freedom of Information Act are marked "Conf iden t ia l " .

Lease Stipulations

The captioned lease is not part of any Biological Sensitive Area, Shipping Fairway, or M i l i t a ry Warning Area. A search for cul tural resources prior to d r i l l i n g 1s not required.

LH9113701 - 0001.0.0

2

Should you require addit ional information, please contact Al Pickett at (504 ) 588-0198 or 588-6312 in our Nev Orleans o f f i c e .

Yours very t ru ly ,

Div is ion Production Administrat ion Manager

ARP/ptc

Attachments

cc : Dis t r ic t Supervisor (w/attachments) New Orleans D is t r i c t Minerals Management Service 1201 Elmwood Park Blvd. New Orleans, LA 70123-2394

Mr. J . H. Pel let ler Shell Development Company P. 0. Box 481 Houston, TX 77001-0481

LH9113701 - 0002.0.0

INDEX OF ATTACHMENTS BOREHOLE" PROJECT

SUPPLEMENTAL PLAN 6F EXPLORATION SOI OCS-G 7963. MISSISSIPPI CANVON BLOCK 807

OrrSHORE LOUIsTATW

ATTACHMENT NO. OF NO. DESCRIPTION COPIES

1 Index of Attachments 9

2 Plat, Transportation Routes and Shore Base 9 Description

3 Description of Act ivi t ies and Hydrogen Sulfide 5* Determination

4 Dril 11ng/Logg1ng/Borehole Testing Procedures # ^

5 Plat, Surface Location of Hells 9

6 Plat, Proposed Bottom-Hole Locations and Depths 5*

7 Structure Map 5*

8 General Information (Schedule of Act iv i t ies, Safety 9 Features, Hydrogen Sulfide Precautions, Pollution -Prevention Features, Vessel Positioning

9-A Drilling Mud Information 9

9-B List Dri l l ing Mud Components and Additives 9

10 Comnients, Spi l l Prevention, Control and 9 Countermeasure Plan

11-A Comments, Air Emissions Data 9

11-B Diagram, Air Emissions Source and Elevation 9

12 Description, Onshore Support Facility and Support 9 Vessels, Description, Travel Frequency

13 Shallow Hazards Comments 5*

14 Chemosynthetic Organisms Comments 9

•Confidential

Attachment 1

LH9113701 - 0004.0.OK

" f j ? f £ 2 T * W-^TTATIO- ROUTO **mUMMTIL run OT ONUMTXON

•01 <>«-« 7K9 UK 007 UliSIMIWI CANTON BLOCK 007

LOUHIMU

NAUTICAL MILES

Y - 1 0 . 2 * 8 . 4 8 0 . 0 0

Y - 1 0 . 2 J 6 . 8 0 0 . 0 0

BEST AVAILABLE COP1'

SURFACE LOCATION

1 S4S7' FNL I 4SffS' FWL Of BLK. 807 J 4S3S' FNL ft 4247' FBL OF BLK. 807 K 5169" FNL 4 2871' FBL OF BLK. 807 L 7531' FNL fc 4838" ' t L OF BLK. 807

ATTACHMENT 5 SHELL OFFBHORE INC.

PROPOSEO SURFACE LOCATIONS fc BATHYMETRY SUPPLEMENTAL PLAN OF EXPLORATION

SOI OCS-6 TVBS BLK. 807 MISSISSIPPI CANYON

•LOCK 607

4000 '

BOREHOLE PROJECT GEHERAL INFORMATION

SUPPLEMENTAL PLAN OP EM7JRATI0N SOI OCS-G 7963. MISSISSIPPI CANVON bLC~CK 807

OfFSHORE LOUISIANA

SCHEDULE OF ACTIVITIES

Exploratory d r i l l i ng may commence as early as June 25, 1991, provided the r i g "Discoverer Seven Seas" is available. D r i l l i ng each location is expected to require about 11 days.

SAFETV FEATURES

The d r i l l s h i p "Discoverer Seven Seas" complies with a l l of the regulat ions of the American Bureau of Shipping (ABS), International Mari t ime Organization (IMO) and the United States Coast Guard (USCG).

HYDROGEN SULFIDE PRECAUTIONS

The geological formations that w i l l be encountered In the Plan wells are not expected to contain hydrogen sulf ide (H 2S). (See Attachment 3.)

POLLUTION-PREVENTION FEATURES

A l l sewage, waste, and chemicals are collected and transported to shore f o r disposal.

VESSEL POSITIONING

The d r i l l s h i p , "Discoverer Seven Seas", Is dynamically positioned and requires no anchoring.

LH9113701 - 0008.0.0

Attachment 8

BOREHOLE PROJECT SHALLOW CORING PROJECT

SUPPLEMENTAL PLAN OF ExTTORATION SOI OCS-fi 7963, MISSISSIPPI CANVON BLOCK 807

OFFSHORE LOUISIANA

DRILLING HUD INFORMATION

The d r i l l i n g f l u i d w i l l be a ge l , fresh water prehydrated and seawater f locculated mud to 1,500 feet below mud l i ne . Prior to entering the sand, the mud weight w i l l be Increased with bar i te and the f l u i d loss lowered with pac f l u i d loss material or starch. The mud weight w i l l range from 8.6 ppg to approximately 10.0 ppg, depending on the weight required to k i l l the water flow from the sands.

MUD AND CUTTINGS DISCHAR6E VOLUMES

DEPTH BML

(FT.)

HOLE SIZE VOLUME

(BBL.)

2,300 9 182

Total Hole Volume Total Cuttings Volume Total Mud Volume

182 bb l . 730 bb l .

2,000 bb l .

LH9U3701 - 0009.0.0

Attachment 9-A

BOREHOLE PROJECT DRILLING MUD COMPONENTS AND ADDITIVES

SUPPLEMENTAL PLAN OF EXPLORATION SOI OCS-G 7963, MISSISSIPPI CANYON BLOCK 807

OFFSHORE LOUISIANA

I . ITEMS USED OW A ROUTINE BASIS

IDF BARIOD M-I MILP ART DESCRIPTION

IDF BAR BARITE/BARIOD F.-I BAR BARITE/MILBAR BARITE (BARIUM SULFATE) IDF WYOMING BENTONITE AQUACSL M-I GEL MILGEL BENTONITE IUF LIGNITE CARBONOX TANNATHIN LIGCO LIGNITE IDF CLS Q-BROXIN R D - l l l UNI CAL BUNDED LI GNC SULFONATE CAiSTTC SODA CAUSTIC SODA CAUSTIC SODA CAUSTIC SODA SODIUM HYDROXIDE AWCNUH STEARATE ALUMINUM STEARATE ALUMINUM STEARATE ALUMINUM STEARATE ALUMINUM STEARATE LDC LIME LIME LIME CALCIUM HYDROXIDE IDF CAUSTICIZED CC-18 CAUSTILIG LIGCON BLENDED LIGNITE/CAUSTIC SOM ASH SODA ASH SODA ASH SODA ASH SODIUM CARBONATE SODIUN MCARBONATE BICARB BICARB BICARb BICARBONATE OF SODA IDF HX-.fiNP BARANEX RESINEX I I CHEMTROL-X/FILTREX SELECTED POLYMER BLEND IOF DRILLINC DETERGENT CON DET. DD M.D. DETERGENT XDP DEFOAM BARA-DEFOAM I DEFOAM-X W.O. DEFOAM/LD-8 DEFOAMER (USUALLY ALCOPJL BASED) IDF RTMUL AKTAFLOS DMS - NONIONIC MUD SURFACTANT IDF CMC CMC OR CELLEX CMC CMC SODIUM CARBOXY METHYL CELLULOSE SALT SALT SALT SALT SODIUM CHLORIDE IDF STARCH IMPERMEX MY-LO-JEL HILSTARCH PREGELATINIZED STARCH IDF AP-21 CYPAN, WL-100, POLYPAC SP-101 CYPAN OR WL-100 SODIUM POLYACRYLATE IDFLO DEXTRID POLY SAL PERM-LOSE ORGANIC POLYMER DRISPAC/IDF-FLR DRISPAC OR PAC POLY-PAC DRISPAC POLYANIONIC CELLULOSE GYPSUM GYP GYP GYP GYPSUM (PLASTER OF PARIS) IDTEX HME/SUPERDRILL HME/SUPERDRIL HME/SUPERDRIL GILSONITE (TREATED) - NATURAL IBFREE BLACK MAGIC SUPERMIX (SFT) PIPE-LAX W BLACK MAGIC SUPERMIX (SFT) MUD CONCENTRATE FOR SPOTTING FLUID IDLUDE ENVIRO-TORQ LUBE-106, LUBE-153 LUBRISAL ORGANIC LUBRICANT MICA MICA TEX MICA (C OR F) MIL-MTCA MICA-FLAKES IDF WALNUT HULLS WALL-NUT NUT PLUC (C, M, OR F) MIL PLUG GROUND WALNUT OR OTHER I JUT HULLS

ATTACHMENT 9-B

LH9LL3701 - 0010.0.0

IPP BARIOD M-I MILPARK

SODIUM CHROMATE SODIUM CHROMATE SODIUM CHROMATE SODIUM CHROMATE IRONITE SfLNCE IRONITE IRCNTTE IRONITE ZINC CARBONATE NO-SULF SULF-X MIL CARD

EJFLOC E-Z MUD POLY-PLUS SEPARAN HAP? SAPP SAPP SAPP

IOH KOH KOH KOH

tea KCL KCL KCL MF-1 MF-1, BORDFTOC MF-1 MF-1

• H I BEN-EX GELEX BEN-EX SOLTEX SOLTEX SOLTEX SOLTEX IDBOND EZ MUD PO'YFLUS NE*JDRILL-HP

IDFLO-LI MY-LO-CEL MILSTARCH

•BD THXXMAIHIN TACKLE 'JFWTHIN

URBJB-F - TACKLE-S MILTEMP VIS7LEX BHC MHH MHH FLOFLEX THEPMACHEK - -

XX. OIL BASE MUD ADDITIVES

INTERDRILL EMUL INVERMUL l^iAMBL CAR30-IEC L

ipnf"* FL E-Z MUL - CARBO-MLT TF—»WTTI DEFLOC DRILTREAI VERSATHIN -INTERDRILL BSE DURATONE VBRSATROL -INTERDRILL V I STONE CEL TONE VERSA GEL CARBO-GEL

IDF QUICK LIME LIME LIME/QUICKLIME LIME

VISTA ODC VISTA ODC VISTA ODC VSTA ODC

LH9113701 - 0011.0.0

IDF BARIOD M-I

I I I . NONROirriHE ADDITIVES

TRADE NAME SUPPLIER ' "SCKIPIICN

A-25 BIOSPOT XC POLYMER ACETIC ACID IDCIDE-P KD-MJ EMI-1267 HP-OO?

HF-iOO CESCO C.IEMICAL MILPARK KELCO MILPARK IDP

HYDRA FLUI'-i POLY«I/XHO L .VATE h • LUBRICANT SURFACTANT/WATER d_Jitt PO.'. S^KT. PIKE SURFACTANT/WATER K'.END FOR TTUC. PIPE XANTHAM CUM (POLYSACCHA.IDV) GLACIAL ACETIC ACID SO!P.^ PTOCIDE

PETROLITE CORROSION INHIBITOK SURFACTANT/WVTER BLEND Fu STUCK "IPE SUCA-7 ..t'ET PULP

f. T AQUALON

I V . METHOD OF DISPOSAL: A l 1 water base rwd and aud j dd ' t l ve s w i l l be uHsposeo ct ov— oarii in to the Guli c f Mexico Lrovided -he aa t e r i a l to d l a " -».d aeeta tb* t o x i c i t y l i m i t specified ln the USE?/ NPDES Or.eral " - - " i l t . GMC28XXX.V. Apv CiulJ conta l r ' r , ; free w i l l Ue rran-.p' • *1 tt- • 29 1 a l t e kot disposal. Diesel w i l l not be used In auds to be 1l.se rgrd, except f o r s p c t l n g to l i ve s'-uck pip* accm'l w.'r-i P j r t «.2'c> o f to* permit. A l l d r i l l cuttings, sand, an.l other wvjll aolids i ' f * J r i l l i n g with water-based nmds w i l l be dlschat«°d overboard. O i f u.»a fltxa ( f i l l i n g wi tb

o-ll-based acl and diesel p l l l r and buffers w i l l r-e r ,u J LO 29 B s i t e f o r disposal.

Revised 1/10/91 KDF

ATTAO.'^M 9-B (CONT'D.)

LH9113701 - 1.012.0.0

EOKLHOL. FPQJFCT OIL SPlTX'flfflTlNCS *Z7 "'LAN

SUPPLEMENTAL PLAN uT TATOOTTIOK s i «CT7»a. ^r^MssiPprgw^orBTjc,. *

SOI's "Oil Sp i l l Contingent PI?'" ms approved b> the MHS on Kc anter 4 , 1987. The la test revisions *:o th*. "0'. S p i l l Contingency Plan" wore subtnltted to the KHS for approval ori Culy 27, 1990. The d r i ' * j i g plans proposed herewith rely primarily on the s p i l l equi^sen*. 5tared at the Clean Gulf Associates base In Venice, Louisiana. Section I I I of the approved plan l i s t s available equipnent at t h i s base plus othor bases fron which addit ional equipment ran be drawn. Section I I l isvs the preventive measures to be taken to i-.ir.1mi.ie o i l ip iV.» and *HP reporting procedures to be followed in the event thet one occr-s. Section VI provides a detai led discussion of the clean-up ,,rocedi/;es to L* In i t i a ted , Including a l i s t i ng of ne personnel who ' -«e up the cusn-up organization.

OIL SPILL RESrDNSE TIMF

Act iv i ty

M?K« calls ( e .g . , agencies, CGA, response team, \essel, e tc . )

Puttc." f .ponse team at Venice

\%i<t\ luipment

Boat run (14 :iautica1 nr..es) \ i \ u /est Delta 30 to Venice (M/V "Mesco 8" wl h .-knot maximum sr,eed)

load oui of equipment

Channel run to open wate • iSW Pass)

Run time to s p i l l location at 12-knot maximum speed for 71 nautical .niles inc lud ing deploymer t )

RESPONSE TIME (Hours)

( )* denotes not In c r i t i c a l path and not included in Response Time.

Attachment 10

Time Requ i red

—rmk)— i

(2)*

3

2

3

6

15

LH9113701 • 0013.0.0

2

A f . v l t v of t*» MMS Sp i l l Trajectory Analysis for th„> subject lease b i j cks (lauricf. - i t e C -58) shows the following probab i l i t ies of a major s p i l l strlklr.3 the l i s t ed land segments within 10 davs of the s p i l l :

SOI would u t i l i ze the f u l l resources of Clean Gulf Associates, as well as the other resources Iden t i f ied In the SOI "Oil SpIV Ccr.tngenry Plan", to jspond st ould th is type of sp i l l occur. This luck-jes seeking appro al for v'o*ex1t 9527 dispersant application I f the resources threatened j u s t n y such a request. The dispersant use decision w i l l be gwl^ad by the MIRG model.

T.ie .urategles and response modes t p 'cfxct resources In the event of a s p l l i threat are stated in Volume I : t i e Clesn 6u. f Associates Operas<!"is Manual.

!*>"-—nee: (A) Draft EIS for Salts 123 anr. 125 published August 1989, •-..•is I.'-36 though 39 and (B) Clear oulf Associates Operations Manual. Volume t l .

L-'.rtu Z Probabi 1vy Vi)

i l . Lafourche, Louisiana 18. Jef ferson, Louisiana 19. Plaquemines, Louisiana

2 1

16

ALU iment 10 (Cont'd.)

I 19*13701 • GVi4.0.0

BORE 101E PRCvtCl KKOJETTtf AIR EMTj ICNS

su OMENTAL PLAN OF ETPTPRKHON SQ! 0Cv-T79o3. HISriSSlPlT^TOTBTfJCK. 807

OFFSHORE LOUISIANA"

DRILLING PHASE

A dynamically positioned d r i l l s h i p w i l l be used for th is exploratory d r i l l i n g . The sources of a i r emissions for a typical d r i l l sh i p are t i e main diesel set (17,000 hp) , an aux U a r y oie;el set of about 700 hp, and an emergency diesel set of about 120 hp. The w i n diesel set 1s assumed to have a 50 percent load f ac to r , and the auxi l iary and emergency sets • r t assumed to have a 1 percent load factor. This to ta ls a dal ly horsepower usage of 204. OCO Sp-hr. or a 30-day monthly to ta l horsepower ••' ge o f 6,120,00* hp-hr. Based on the emission rates for o i l - f i r e d

x ip rocat ing engines (Table 4.A of EPA . Report 450/3-77-026 ent i t led Atmospheric Emissions from Of f i nor ii Oil and Gas Development and

• i educt ion") , the following gaseous emissions would be generated for each wel l during th* 11 days/well r r l l h n g operation:

DISCHARGE (METRIC TONS) PTOILL ANNUAL RATE

N0¥ 3i.fa 1057.9

so2 .15 71.3

HC 1.06 35.3

CO 4.67 155."'

Particulates Unknown Unknown

WATrq TRANSPORTATION

The norsepower usage of the two vessels to be i»sed in connection with th is operat ion 1s s follows:

190 F t . Cargo Vessel

2400 hp x .80 (load factor) x ^fpTp' * ^montR5 x * 3 7 m o n t h s = 1U.347 hp-hr

80-100 Ft . Stano^y Ves el

161" hp x .80 (Irad tactor) x 2 j a ^ - x 11 days

10)0 hp x .80 (loaj factor) x

days

1 hr. day x 11 days

- 33,396 i>-hp.

s.800 np-hr

TOTAL * 161,543 hp-hr.

Attachment 11-A

LH9113701 - 0015 0. r,

2

Based on Table 4-4j the gaseous emissions generated by water crar.sc--cation are as fo l l ows :

DISCHARGE (METRIC TDVil Kb vl|LL AHNUA -. 'felT

2.» 77.C

so2 0.16 5.2

HC 0.08 2.o

CO 0.34 11.3

Particulates Unknown Unknown

TOTAL ANNUAL DISCHARGE (METRIC TONS)

CO

TSP, S0 2, NC., VOC 1 **.2

Emission Exemptions

The proposed location u . £3 statue miles from the nearest shoreline. Therefore, the emission exemption (E) f o r the various pollutants 1s as fol lows:

CO E • 3400 ( 5 3 ) 2 / 3 - 47,973 Tr.is/' \

TSP

so2

N0X E • 33.3 (63) = 1,765 Tons'Yr.

The t o t a l annu*1 d<scharc,e does not exceed the exemption totals above; consequently, r \ furthe a i r qua l i t y review 1s required for the emissions from the operation; in connection w i th th is plan.

EMISSIONS' LOCATION AND ELEVATION

The diesel exhau.t stacks are located fore of the helideck. The elevation at the out le t Is 80 ."eet above the keel (55.25 feet above the water level when the sh ip 1s fu l l y loaded).

Attachment 11-A (Cont'd.)

LH9113/01 - 0016.0.0

Attachaent 11-B

BOREHOLE PROJECT SUPPLEMENTAL PLAN OF EXPLORATION

SOI OCS-6 7M3. MISSISSIPPI CANVON BLOCIC 807 ONSHORE LOUISIANA

ONSHORE SUPPORT FACILITY

The onshore support bese for this activity will be SOI's existing Venice Terminal. This facility 1s located on the Mississippi River near Venice* Louisiana, approximately 35 miles upriver from the Gulf of Mexico. The physical plant covers 14 acres and Includes 1,000 linear feet of waterfront, 3,000 square feet of office space, 3,200 square feet of personnel quartering space and 7,200 square feat of covered warehouse area. One 45-ton crane and two fork trucks are used for materia7 handling operations. No expansion of the Venice Terminal will be required for this activity. In addition to the above, tubular goods will usually be shipped by land to Venice from one of the contract warehouses located In Morgan City, Louisiana, which will also require no expansion. Also, while personnel transported by helicopter will be picked up and returned to SOI's Venice Terminal, both Air Logistics and PHI operate bases at Venice for refueling and maintenance.

SUPPORT VESSELS

TRIPS ITEM SiZE OR MODEL USE PER WEEK

Boat 190'+ Cargo 3 or 4

Boat 190*1 Standby N.A.

Helicopter Bell 206B, 212. 214 or Crew Change and Misc. 18 to 22 412

Boelkow 105

Aerospatiale 330-J

Sikarsky 5-76

LH9113701 - 0017.0.0

Attachment 12

CHEMOSYNTHETIC ORGANISMS goi QCS-Q MISSISSIPPI CANY9W BLQCK M l

CFfSHQPP, LOUISIANA L o c a t i o n I t X - 923,413

Y - 10,227,153

Location J ! X- 922,987 Y - 10,228,105

Location K: X- 921,591 Y - 10,227,471

Location L: X- 923,558 Y- 10,225,558

Scientific investig-.tlona have discovered tha presence of benthic r-imunitiea thriving near active fluid axpulaion zonae on e seafloor in sone regions of the Gulf of Mexico. For this reason, SOI examined al l shallov hazards data cover­ing proposed locations I , J, K, and L. There ara no fluid explusion tones within 8000 feet of any of these proposed locations.

SOI believes that the planned exploratory drilling activity within the captioned Mississippi Canyon Area v i l l not distrub any chemosynthetic organisms.

With reference to NTL 83-3 of September 7, 1983, paragraph I I . 1.5, a copy of intermediate resolution data from the tvo linea closest to our proposed well location v i l l ba furnished i f request* "

2£4£z.

Division Geological Engineer Shallov Hazards Interpreter

Attachaent 14