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t?;a act *.v i t *«»••> proposed f&r - v i i ' .

tv no* being cnnviUftrOd for c ; r v v * ' .

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SOHIO] SOHIO PETROLEUM COMPANY

CONTINENTAL & O F F S H O B E DIVISION

Hr. D. J . Bourgeois Minerals Management Service 1201 Elrvood Park Blvd. New Or ^ns. LA 70123-2394

February 22, 1988

940' SOUTHWEST FHEEWAV SUITE «12O0

HOUSTON -EXAS 77074 -M3-M--11SO

PUBUC IKFC.wV.AflOII—

Re: Supnlemental Plan of Exploration Ship Shoal Bloclc 368 OCS-G-5590, Well "G" Offshore Louisiana

Dear Mr. Bourgeois:

Enclosed are five (5) Confidential and six (6) Public Information copies of the Supplemental Plan of Exploration (POE) for the above referenced project. Accom­panying this POE are one (1) set of processed seismic line data offsetting this location. Two (2) copies of the Hazard Study for Ship Shoal Block 368 were pre­viously submitted with the i n i t i a l POE on May 22. 1986.

I * you have questions or require additional information, please call Cynthia Arnold at 713/778-6417. —

Sincerely,

Cary w/ Kerlin Offshore Business Unit Regulatory Supervisor

CLA/brg Attachments

SUPPLEMENTAL PLAN OF EXPLORATION

OCS-G-5590

SHIP SHOAL BLOCK 368

OFFSHORE LOUISIANA

February 22. 1988

LIST Of ATTACHMENTS

A. Letter from Sohio Regional Geophysicist

B. Vicinitv & Well Location Plats

C. Structure Map & Geologic Cross Section

0. Orilling Mud Components

E. Air Quality Review

SUPPLEMENTAL PLAN OF EXPLORATION SHIP SHOAL BLOCK 368

OC5-G-5590 OFFSHORE LOUISIANA

Pursuant to the requirements of 30 CFR 250.23.1, Sohio Petroleum Company

submits the following Supplemental Plan of Exploration (POE) for Ship Shoal

Bloclc 368.

(i ) EXPLORATION ACTIVITY

The proposed exploration activity for the subject tract consists of d r i l l ­

ing Well "G", in addition to the six (6) wells covered in the in i t i a l POE.

The r6" location w i l l be drilled as a straight hole. The estimated time to

dr i l l this one (I) exploratory well is about forty-five (45) days, with a June

I , 1988 anticipated spudding date for this location.

( i i ) PROPOSED ORILLING RIG

Sohio presently has under contract the SEOCO 706 semi-submersible drilling

rig, which w i l l be used for this project. This rig is capable of drilling to

25,000' in water depths of 2.000'. Specifications and drawing of this rig's

diverter and BOP system have been sent to your office on May 22. 1986 with the

initial POE.

( i i i ) GEOPHYSICAL WORK

All of the geophysical work preparatory to initiation of exploratory opera­

tions has been completed. A velocity survey may be run on these wells when

total depth has been reached. No other geophysical work is planned unless

data obtained from drilling operations necessitates additional definition

detail from conventional reflection ssismic methods.

Supplemental Plan of Exploration Ship Shoal Block 368 Page 2

A shallow hazard report entitled "Hazard Study Blocks 360 and 368, Ship

Shoal Area" was prepared by John Chance & Associates, Inc. and two (2) copies

were previously submitted with the i n i t i a l POE on May 22, 1986.

The Ship Shoal Hazard Study has been reviewed by Mr. Jack Golden, Sohio's

Regional Geophysicist. Attachment A is a letter from Mr. Golden in which he

agrees with John Chance's conclusions and addresses shallow hazards at the "G"

well site in Ship Shoal Block 368.

(Iv) VICINITY AND LOCATION MAPS

Attachment 8 is a vicinity map depicting the subject tract's position rela­

tive to the Louisiana shoreline. No new onshore facilities will be required

for d r i l l i n g the proposed exploratory well. Existing service company f a c i l i ­

ties in the Fourchon Area have sufficient capacity to accommodate this project

without modification or expansion.

Attachment B-2 shows the proposed surface location for Well "G" which will

be drilled as a straight hole. The water depth and surface loca­

tion for this well 1s as follows:

Well "G"

Water Depth: 468' Surface Location: 6,500' FNL

550' FEL

(v) STRUCTURE MAPS AND CROSS SECTIONS

Structure maps and cross-sections are included in the five (5) confidential

copies of this Plan as Attachment C. Oepths shown on cross-sections and

structure maps are sub-sea measurements.

Supplemental Plan of Exploration Ship Shoal Block 368 Page 3

(vi) OTHER RELEVANT DATA

(A) 0J_J.Spi 11 Contingency Plan

Sohio Petroleum Company is a member of Clean Gulf Associates (CGA) and

would utilize that organization's equipment to clean up an oil s p i l l .

The closest CGA bases are at Fourchon, Grand Isle and Houma, Louisi­

ana, respectively. Response times for CGA Fast Response Units from

these locations, would be 12, 13 and 13 hours respectively. Manpower

to operate the r >'•» equipment would be provided by Peterson Maritime,

Services. Inc., <jse personnel are trained for oil spill clean up

operations. Sohio's supervisory personnel would direct the clean up

operations until successfully completed. Additional details can be

found in Sohio's 1987 011 Spill Contingency Plan which has been

approved by the Minerals Management Service.

(B) List of Mud Components

Attachment D is a list of the proposed dr i l l i n g mud components and

additives, including the common and chemical trade name ot each addi­

tive.

(C) Gaseous Emissions

Exploratory drilling operations will be conducted from the surface

sites described in Section (iv) using the mobile dr i l l i n g unit des­

cribed in Section ( i i ) . Operations will be of a maximum duration of

forty-five (45) days.

Supplemental Plan of Explorat ion Ship Shoal Block 368 Page 4

At the d r i l l s i t e , gaseous emissions w i l l be generated by the r i g en­

g i n e s , the attendant work boa t , stand-by boat , crew boat , and h e l i c o p ­

t e r , and the product ion t e s t i n g of possib le p rospect ive r e s e r v o i r s .

Gaseous emissions at the dock s i t e in Fourchon, Lou is iana, w i l l be

generated by the work boat , crew boat and h e l i c o p t e r . Onshore sLaging

f o r t h i s operat ion w i l l be from e x i s t i n g f a c i l i t i e s , so there w i l l be no

s i g n i f i c a n t Increase in emissions fo r t h i s a c t i v i t y . Projected emis­

sions f rom th i s a c t i v i t y have been ca lcu la ted and are presented i n

Attachment E e n t i t l e d "A1r Ou ! i t y Review".

(D) Coasta J Zone Hanagemen t_ (C ZM)_ Con s is tency C e r t i f i c a t i on

An Environmental Report and Consistency C e r t i f i c a t i o n was included in

the i n i t i a l POE. Proposed a c t i v i t i e s described in t h i s Supplemental POE

w i l l a l so be conducted in a manner cons is tent w i t h Lou is iana 's approved

CZM programs.

STANDARD OIL PRODUCTION COMPANY

Sice Clearance Le t te r Ship Shoal 368 (OCS-G-5590) DATE: January 15, 1988

Offshore Business Development Un i t Geophvsicists conclude that no s i g n i f i c a n t shallow d r i l l i n g hazards e x i s t w i t h i n 500' of the Ship Shoal 368 supplemented "G" we l l l o c a t i o n (6500' FNL, 550' FEL; W.D. = 4 6 8 ' ) .

The o r i g i n a l records and summary repor t of a shallow hazard survey conducted by John E. Chance and Associates f o r Standard O i l Production Company over Ship Shoal 368 have been reviewed. We are i n agreement w i t h t he i r f i n d i n g s and conclude t h a t :

1) No obs t ruc t ions are observed on the sea f l o o r w i t h i n 500 f ee t of the proposed l o c a t i o n . The sea f l o o r dips south at a ra te of 25 f e e t per mi le .

2) Seismic data at the proposed l o c a t i o n Ind ica t e a t h i c k sequence of s u b - p a r a l l e l bedded sediments (over 1,500 f e e t ) tha t d ip to the southeast. The ra te o f d ip on the hazard s t r uc tu r e map i s 265 f e e t per mi le .

3) No gas accumulations or f a u l t s are observed at the proposed w e l l l o c a t i o n w i t h i n the upper 1,000 f ee t below mudline (1,468 f e e t below sea l e v e l ) .

Attachments include annotated copies of the p inger , d i g i t a l minisleeve exploder, s ide scan sonar and magnetometer records f o r l i n e s 13, 34 and 35.

Approved b y : '- ' •'<• A < I t*. • / G. M. Nichols

Concurred: M. F. Smith

Prepared by: ^ : A ?_ k \ { L ^ t V u [ Q C 7 / Oldroyd/W. Keach

ATTACHMENT A

368 O C S - G - 5 5 9 0

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a,9oo' 5 . 2 5 0 -

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I S O

5 5 0*

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!F» SL 1 J ? 0 0 '

ATTACHMENT B S C * t C l.OOO"

B L O C K 3 6 8 S N I P S M O A L A « C *

* R O F O S £ 0 WCI.L LOCATIONS

c « y. S C A B S

7!—

S./.KS 'L PRODUCTION COMPANY

ORILLIWG MUD COMPONENTS

Products of Oresser-Magcobar O r i l l i n g F lu ids S t r v l c t s a r t l i s t e d 1n tn1s program f« i l l u s t r a t i o n purposes. Equiva lent or comparable products are a v a i l a b l e from oth« s e r v i c e companies sucn as IMCO Serv ices. M l l p a r k . and N . L . Baro id .

Trade Name

Magcogel

Caust ic

Lime

Rapid Mud

"*gCGnOl

Magcobar

K-17

Spersene

Orispac

Bicarb

KXP-20

KOH

ES-B28-M

XC-Polymer

Composition Purpose

Wyoming Bentonlte; A naturally Provide good filter cake occurring element containing plates quality, filtrate control. of Silica and Alumina (Inert).

Sodium Hydroxide

Calcium Hydroxide

High Molecular We1g< . Anionic Liquid Polymer

2-ethy1hexano1, 2-etby1hexy1 alcohol

Barite: BaSO*

Potassium Lignite

Chrome-L1gnosu1fonate

Polyanionic Cellulose

Sodium Bicarbonate (Na HC03)

Potassium Chrome Lignite

Potassium Hydroxide

Proprietary Guar Gum based polymer

Xanthan gum

& viscosifier for water base drilling fluid.

Alkalinity Control

Alkalinity Control

Viscosifier. imparts shale stabilization

Oefoamor

Weighting Agent

Thinner, fluid loss : 1t1vo, potassium source

01soer;ant, fluid loss contral

Fluid loss control and viscosifier

Treating out cement

Thinner. Inhibitor, fluid loss additive, and potassii source

Alkalinity source and potassium source

Shale encapsulator

Viscosifier and fluid loss additive.

ATTACHMENT D

Air Quality F.evi >-For

Ship Shoal Arec 8'ocr 3& 0CS-6-f.o9C

Cohlo Petroeum Company 9401 Southwest Freeway

Hcusto... l : a', 77074

Submitted to Cary W. Ker l l r

Regulatory Supervisor

Feb jr*- }.% i :-St>

Prepared by John E. Chanc? 4 Associates, Inc.

Regulatory A Environmental r v ls lcn Project No. 88-8023

John £'. (Jhs ice A Assoc.. Inc. -ATTACHMENT E

Projected Emissions Srheduie for Project

t . General Infor at'en

Lecatlon of FACT!I ty - Shfp Shoal rea Block 368 of Rig/Platform - Semi-subrw.-rsinle

t»*ner/Operator - So'ilo Petroleum Cc c-ny C401 Southwes'.. rreeway Suite 1200 Houston, Texas ~70 4

Contac' 'v 'zzn - Cary H. Kerl ln Regulatory Superviser

Troje A H a r t Dtts - June '., 1988 Projei t End Date - July 15, I53f»

7,800 Feet to Ke Dr i l led 73 Mles Ott-hore

I I . Total Emissions for f i r m i n g

Tola! Time for D r i l l i ng 1 we l l : 2 months

Projected Emissions (Tons/honth of Dr i l l i ng )

Emitted Suhsur.ce CO S02 N0X VOC TSP

D r i l l i n g Operations 4.36 0 22.66 1.43 0.32

A. Transportation Emissions, 0 i ' i l ing

Projecte- isslons (Tons/Month ot Dr i l l i ng)

Emitted Subi'.ance CO SO, N0V VOC TSP

Crewboat 1.30 * 9.10 0.49

Supply Boat 0.03 0.03 0.17 0.02 *

Helicopter C.25 0.01 0.03 0.02 0.01

John E. Chance A Assoc., Inc.

8. Miscellaneous, D r i l l i ng

Projected Emissions (Total Tons)

Emitted Substance CO S0? NO. A

VOC TSP

Tow Tugboat(s) 4.?? * 19.98 1.60 *

Cementing Skid •J.OS 0.01 0.15 0.01 0.1)1

Crewboat horsepower of 2,500 Fourchon, Louisiana Waiting Time 4 hour(s) per t r i p

14 t r lo (s ) per week

Suppiy boat w i l l 200 kw generator Fourchon, Louisiana Waiting Time 10 he-jrs(s) per t r i p

4 tr1p(s) per week

Helicopter Fourchon, Louisiana

10 t r ip (s ) per week

Towing Tugboat horsepower of 4,500 Working for 6 day(s)

Cementing Skff "orsepower of 400 Working for Jay's) per well

Project Summary, Total Emissions

Emitted Substanca CO S0? N0X VOC T>*>

Allowable (tons/yr) 59387 2431 2431 2*31 243.

Projected Emissions (Tons/Year)

Year 1 8.72 0.81 45.32 2,86 0.6k

Total Emissions are comprised cf all Const-...::fon, Dri 11 Ini, 5nd Production Emissions.

John E. Chanco A Assoc., Inc.

I I I . Project Summaryt Total Emissions (cont 'd.)

This my Include the followlnq which are not "?edf1ed 1n each section:

- Weld*ng machines end cranes u t i l i zed Airing construction and d r i l l i n g oparations.

- Crane(sj, Ge/!era».or(s), ; i t j t e r Treater, and Compressor u t i l i zed during production.

IV. Findings of Air Quality Review

As per DOI-MMS regulations, th is f a c i l i t y Is exempt vrom further a i r quality review as i t has been determined that i t * i te ra t ion «*111 not have a s igni f icant adverse environmental impaci cr a i r qual i ty . Calculated emissions are for a worst case condit ion, ftctual emissions from this project w ^ l probably be lower.

V. Methodology

Dr i l l i ng - horsepower-hour/ft d r i l l ed method Boats - horsepower-hour method Hel icopter - landing/takeoff (LTO) cycle methoo A l l Other- - horsepower-hour method

V I . References

ATMOSPHERIC EMISSIONS FROM OFFSHORE OIL DEVELOPMENT AND PRODUCTION, EPA 450/3-77-026 (June, 1977).

COMPILATION OF AIR POILUTANT EMISSIONS FACTORS, EPA Report AP-42 (September, 1985), 4tT Edit ion.

* The EPA does not provide- and T*r emission factors for boats.

John E. Chance 6 Assoc., inc-