In Reply Refer To: MS 5231 December 4, 1992

ARCO Oil and Gas Company Attention: Ms. Brenda Y. Munoz Post Office Box 134C Houston, Texas 77251

Gentlemen:

Reference Is made to the following plan received November 20, 1992:

lype Plan - I n i t i a l Plan of Exploration Lease - OCS-G 9611 Block - 78 Area - Ship Shoal Activities Proposed - Wells A through D

In accordance with 30 CFR 250.33, this plan 1s hereby deemed submitted and is now being considered for approval.

Your control number 1s N-4396 and should be referenced In your communication and correspondence concerning this plan.

Sincerely,

3" (Oris- Sed.) A Onnnld Oiroir

0. J. Bourgeois Regional Supervisor Field Operations

bcc: f Lease OCS-G 9611 POD File (MS 5032) MS 5034 w/public info, copy of the plan

DTrocquet:c1c:11/27/92:POECOM

1

ARCO Oil and Ga* Company O

\ , i s ! ' i n O u t f i t !

.'}«jy«jiaiory Compliance and C »• .'•". *>T-.?T'!ai Department

November 19, 1992

Mr Dan B Bourgeois Regional Supervisor - Field Operations GULF OF MEXICO OCS REGION Minerals Management Service U S Department ofthe Intenor 1201 Elmwood Park Boulevard New Orleans, LA 70123-2394

RE PLAN OF EXPLORATION Slup Shoal Block 78 OCS-G 9611

Dear Mr Bourgeois

ARCC' Oil and Gas Company, a Division of Atlantic Richfield Company, hereby submits five copi- - I'an initial Plan of Exploration and tour public infonnation copies describing the proposed drilling of four exploratory wells on Ship Shoal Block 78 The first well is to be spud on or about i-inuary 1, 1993, with a rig such as the Teledyne 20

If need any further information, please call me at (713) 584-6837

Brenda Y Munoz Regulatory Compliance Coordinatoi

N F Usher HMB 1222 (w/o attachments) M Sinitiere BBS (w/o attachments) SS7IOen l se WF -BYM

Sincerely.

ARCt) Oil and < ia Company A Division ot Atlantic Richfield Company PUBLIC MFOMMMIN

PLAN OF EXPLORATION

For

Slnp Shoal Block 78

OCS-G % l I

This Plan of Exploration for Ship Shoal Block 78. OCS-G 961 I . was prepared in accordance with 30 CFR § 250.33. Notice to Lessees 83-3. Letters lo Lessees dated October 12. 1988 and September 5. 1989. and Department of Intenor Secretarial Order 2974. revised January 19. 1977

Ship Shoal Block 78 was leased dj ARCO Oil and Gas Company in thc March 30. 1987 Central Gulf of Mexico Oil and Gas Lease Sale 113 The proposed exploratory activities include thc dnlhng of four wells in Ship Shoal Block 78. Dnlhng of the first exploratory well is scheduled to begin about January I . 1993. subject to approval of the Plan and subsequent Permit to Dnll Thc proposed well locations and spud dates arc as follows The schedule is tentative in thc meaning of 30 CFR § 250 33-1 (a)

Well Depth Water Drilling Anticipated

t̂ cat»vn Loiiiss PTVD Depth Bra sPud Date

A SHL 900' FSL A 2500'FWL 21' 60 January1. 1993

B SHL 1400' FSL & 45O0TWI 21' 60 March I . 1993

C SHL 2000' FSL A 8000 FWL 21' 60 May I . 1993

D SHL 7900'FSL A 17(MITEL IK' 60 July I . 1993

Additional exploratory drilling must bc predicated upon thc nerd to define reservoir limits and/or structures The installation of platforms, producing facilities, and pipelines arc contingent upon thc success of thc proposed wells. Other exploratory activities which may bc conducted under this plan are a wellbore velocity survey and soil boring.

Ship Shoal Block 78 Exploratory Wells A through D will bc dnlled using a ng such as Moviblc Offshore. Inc dnlhng unit (MODU). Teledyne 20 This is a nut supported jackup type dnlhng rig capable of drilling to 25.000 foot depths in 17 to 250 feel of water Schematics of the Iclcdvnc 20 is attached with a description of thc safety and pollution-prevention cquipiiK I s\sicm ARCO Oil and Gas Company supervisory dnlhng personnel arc trained in blowout prevention and control procedures

Plan of Exploration Sh?- Shoal Block 78 Page 2

ftJ8UC INFORMATION

SUPPORTING INFORMATION FOR PLAN OF EXPLORATION FOR SHIP SHOAL BLOCK 78

1. A structure map showing thc proposed well locations, a cross-section and lop of abnormal pressure plat arc attached 2. Thc water depth across Ship Shoal Block 78 vanes from 15 feet to 24 feet A map snowing the proposed well

locations and bathymetry is attached

3. A shallow hazards geophysical survey was conducted on board thc H O S. LONE WOLF from September 18 through September 23. 1989 by Marine Technical Services. Inc. A Shallow Hazards Report and maps were prepared by Dale L Harbcr. Independent Geophysicist and arr attached

A site-specific review of thc shallow hazards dala for thc immediate vicinity of thc proposed vn Ils indicates that there is no hazard to drilling at thc proposed surface locations. All surface locations are at least 500 feet from any possible shallow pressured gas or possible hard bottom areas on the seafloor Also, all locations arc at least 1500 feet from two pipelines that traverse the block

Ac ual lines of data may bc obtained from Mr Nat Usher. ARCO geophy sicist in Houston. Texas Mr Usher can be reached at (713) 584-3214

4 ARCO has an Oil Spill Contingency Plan which was approved by the MMS on August 11, 1988 SpiU reporting procedures and a list of company personnel rcspons J:-. for pollutant spill cleanup are contained in the Oil Spill Contingency Plan. ARCO's onshore base in Bayou Boeuf will bc used for support during thc proposed drilling operations and in the event of an oil spill. Clean Gulf Associates (CGA) has oil spill cleanup equipment available for use by ARCO. as a member company Thc equipment is stored at Grand Isle Venice. Cameron. Houma. Theodore and Intracoastal City. Louisiana and at Galveston. Texas City. Port Aransas, and Fulton. Texas.

(1) Oil and gas production arc expected to bc tound on this lease Should a spill occur a Fast Response Unit would bc obtained from the Clean Gulf Associates inventory io remove oil from thc ocean in order to prevent or minimize any potential shoreline impacts As indicated in ARCO's Oil Spill Contingency Plan additional cr uipmcnl for thc removal of oil at sea and for shoreline cleanup would bc obtained from CGA as needed for thc particular situation Thc nearest location for a FRU is in Houma with alternate locations in cither Intracoas'al Ciry or Grand Isle.

(2) Response lime to Ship Shoal Block 78 is estimated at 11 hours Response tunc is estimated as follows All boat travel times arc based on a traveling speed of 9 knots in open waters with approximately 3 hours additional travel time to reach the Gulf from the Bay ou Boeuf Shorebase A boat is usually kept at thc ARCO shorebase

A Locate and move boat Truck FRU from Houma to Base

Ohr l o h r

B C

Contract labor to base CGA Supervision lo base

3 5 hr 2 0 hr

Total Procurement time' Equipment Loadout Transport to spill '25 mi from open waters) Equipmc i Deploy ment

J 5hr I ohr 3.5 hf I Q hr

TOTAL RESPONSE TIME II hrs

Total procurement lime is thc maximum of categories A. B. and C

Plan of Exploration Ship Shoal Block 7K Page 3

(3) Site-specific review of the planned activilies have been conducted using thc methodology employed in thc Final Environmental Impact Statement for Gulf of Mexico Sales 131. 133. and 137. According to Figure IV-2 the proposed dniling location is in launch site 36 and probability for landfall of spilled oil within 10 days is: 3% to New Iberia Parish. La. 11% to St Mary Pansh. La. and 27% to Terrebonne Pansh. La

A review of Biological Map No. 6 included in thc CGA Manual Volume II indicate thc New Iberia. St. Mary' and Terrebonne Parishes coastal areas lo bc mostly marshland The area consists of recreational beaches, barrier islands, mangroves, oyster beds, live rangia clam beds and bird rookeries Please notc thai thc Cypremon Point Sute Park, thc Shell Keys National Wildlife Refuge, the Marsh Island State Wildlife Refuge, and the Atchafalaya Delta Wildlife Management Area are all within this three parish area Endangered species that inhabit thc area are thc bald eagle

Response modes for onshore protection and cleanup arc referenced in the CGA Manual Volume I I . on thc pages immediately following thc abovementioncd maps of biological sensitivity Priority for a shoreline cleanup would bc given to environmental ly sensitive areas w h u i would be cleaned using these recommended methods as outlined in UV CGA Manual Volume II

5 No new or unusual technology is to bc utilized for Ihe proposed exploratory drill ing on Ship Shoal Block 78

6 Thc lease stipulations for archeological cultural resources include Ship Shoal Block 78 A Cultural Resources Report is required and was prepared by Northland Research. Inc Thc Cultural Resources Report is attached lo the Geophy sical Survey Report

7 Effluent waters, deck drainage, formation waters, and dnlhng fluids wi l l bc disposed of according to the stipulations of the U S Environmental Protection Agency's National Pollutant Discharge Elimination System (NPDES) General Permil GMG 285716 Water based dnlhng fluid and cuttings which meet the NPDES General Permil toxicity limitation ofa % hr LC50 of greater lhan 30,000 ppm will bc discharged overboard Other water based muds and oi l based muds will cither bc transported back to shore for reclamation or disposal at zn approved commercial facility or will bc disposed by annular injection in an offshore well on thc lease No waste products which contain oi l wi l l bc disposed of into the Gul l of Mexico

Dunng the proposed dnlhng on this lease wastes likely to bc generated include 1450 bbls dnlhng fluid and 3800 bbls cuttings estimated based on dri l l ing a 26" hole to I0001, 17-1/2" hole to 4500'. 12-1/4" hole lo 9000* and 8-1/2" hole lo TD If watcrbascd fluid is used thc mud and cuttings wil l bc discharged overboard at rates of less than 1000 BPD A list of typical mud sy stem additives H attached

Also generated will be an estimated 12 bbls/day sanitary waste. 160 bbls/month deck drainage from rainfall and equipment and dnlhng deck washings Sanitary wastes wil l bc treated onboard with U S Coast Guard approved sanitation treatment facilities Deck drainage will bc routed through a skimming sy stem to remove any free oil No waste wil l be discharged that contains free oil

Domestic wastes and any chemicals generated will bc brought to shore for disposal at a commercial lacility

8 ARCO Oil and Gas Company, a Division of Atlantic Richfield Company, hereby requests that in accordance with 30 CFR § 25067(c) thc above area bc classified as "Zones where thc absence of IhS has been confirmed " Seoul tickets from thc four wells which have been drilled on SS 78 Oxy #2. Odeco 91, Aminoil *2, and Walter 03 have been reviewed Thc infonnation confirms that I^S is not present in thc area

9. A Certificate for Coastal Zone Consistency is attached

Plan of Explorac-rt Ship Shoal Block <J Page •»

10. Air Emissions

Source of Emissions

MODU TELEDYNE MOVTBLE 20 3 - EMD SR12EW1W 1620 hp diesel engines on main generators 2 - GMC 8V-71N diesel engines drive cement unit I - GMC 4-7IT diesel engine powers electric logging umt

A ng schematic showing point sources of air emissions is attached

As per the guidelines contained in 30 CFR § 250.43(d). Exemption Formulas, the activiues described in this Plan JC below the exemption levels. Thc emission exemptions are calculated as follows based on the distance to nearest shoreline of 19.26 miles from Ship Shoal Block 78 to U S.C.G.S. benchmark 'OYSTER 2'

NO,, SO,, VOC, TSP = 33.3 (19 26 miles) TPY - 641 TPY

CO • 3400 (19 26 miles)2 3 TPY - 24430 TPY

Calculation of Projected Emissions

Emission Factors' -

1 - Table 3.4-1 F ™Ttf l« FlflfTT f n r 8MtiBMP ' — B f f l n , w l timM F T " ~ EPA Report AP-42

Assumptions

q-mptions

Nitrogen Oxides (NO x) Sulfur Oxides (SO.) Volatile Organic Compound (VOC) Particulates (TSP) Carbon Monoxide (CO)

24 01b/ 1000 hp-hr 2.8 Ib / 1000 hp-hr 0.63 Ib / 1000 hp-hr 2.41b/1000 hp-hr 6 4 Ib / 1000 hp-hr

Drilling time per well 60 days

Percent of time with 3 generators at 75% power Total power usage at 75% Percent of time with 3 generators at 25% power Total power isag? at 25%

75%

25% 3937 M BHP HRS

438 M B HP-HRS

Cement pump operating time at 195 BHP or less (2 hr/week testing BOP. 5 hr/casing string)

40 hrs

Cement pump power usage 8 M B HP-HRS Logging unit operating time

GIH-idling (§90 BHP POH - variable % 120 BHP

40 hrs 40 hrs

Logging mul pgTTT gsjsj| 9 tM B HP-HRS

SUBTOTAL HP-HRS for diesel powered engines

TOTAL HP-hrs for diesei powered engines for four wells

4392 M BHP-HRS

17568 M HP-HRS

Plan of Exploration Ship Shoal Block 78 Page 5

Nitrogen OxiacsuNtV 5 5 l 2 D S

2 4 w M H p _ h r % ( 7 5 6 g M ^ ^ x Q ^ 5 l Q n / l b

-2108 TNOx

Sulfur Oxides (SOx) 2 8 lb/ M HP-hr x 17568 M HP-hr x 0 0005 ton/lb - 24 6 T SOx

Carbon Monoxides (CO) 6.4 lb/ M HP-hr x 17568 M HP-hr x 0 0005 ton/lb = 56 2 T CO

Volatile Organic Compounds (VOC) 0 lb/M HP-hr x 17568 M HP-hr x 0 0005 ton/lb - 5< TVOC

Particulates (TSP) 2 4 lb/ M HP-hr x 17568 M HP-hr x 0 0005 ton/lb -21 I TTSP

Total Emissions for Wells No A through D lb/day ton/yr Eiemption

ton/vr Nitrogen Oxides ( N 0 X ) 1155 2108 641 Sulfur Oxides (S0 X ) 135 24 6 641 Carbon Monoxides (CO) 308 562 24430 Volatile Organic Compounds (VOC) 30 55 641 Particulates (TSP) 116 21 1 641

11 The Environmental Report for Ship Shoal Block 78 is attached

12. Ship Short Block 78 is located approximately . v 26 miles from U S C G S benchmark "OYSTER 2V DriUing operations will be supported from ARCO 0-1 and Gas Company's Bayou Boeuf Shorebase in Amelia, Louisiana. No new facilities are expected to be required to support the proposed operations The frequency of helicopter flights for transportation of dnlhng and contract personnel to the Teledyne 20 dunng dniling operations 15 estimated to be 10 round tnps per week. During drilling activities one workboat will ave raft about 15 round tnps per week. Workboats are typically 160* to 200' in length and travel up to 9 knots in open waters A utility boat may also be used to supplement tbe workboat as needed Utility boats arc somewhat smaller lhan workboats, generally only 100' to 110' in length. A crewboat will also be utilized for the weekly crew change dunng times when helicopter travel is restricted due to weatner. Crew boats are generally 110' to 120' in length with and aluminum hull and travel at about 20 knots A Vicinity Plat is attached for reference which shows the likely route for travel between the shorebase and Ship Shoal Block 78.

13. Water depths in Ship Shoal Block 78 are less lhan 400 meters, therefore, no effect on chemosynthetic communities is likely

14 Common Depth Point seismic lines will be submitted upon request

15 Thc authorized representative of Atlantic Richfield Company to whom questions regarding this Plan may be addressed is

Brenda Y Munoz Regulatory Compliance Coordinator

PO Box 1346 Houston. TX 77251

(713) 584-6837

SS 78 OCS-G 9611

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fl 9 0 0 ' PSL 4 2S00- P N L 9 i«CO- PSL 4 4 5 0 0 ' PWL C 2 0 0 0 PSL 4 8 0 0 0 1 PWL 0 790C c S L 4 ! 7 0 0 ' PEL

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N ARCO O I L AND GAS COMPANY

LOCATION PLAT BLOCK 78

S H I P SHOAL AREA SCALE:1"=2000 ' NOVEMBER 1392