UNITED STATES GOVERNMENT April 14, 2021 MEMORANDUM To: Public Information From: Plan Coordinator, OLP, Plans Section (GM 235D) Public Information copy of plan Subject: Control # - S-08035 Type - Supplemental Exploration Plan Lease(s) - OCS-G19409 Block - 815 Alaminos Canyon Area OCS-G31195 Block - 728 Alaminos Canyon Area OCS-G32988 Block - 771 Alaminos Canyon Area OCS-G35153 Block - 772 Alaminos Canyon Area Operator - Shell Offshore Inc. Description - Subsea Wells AA - UU DP Rig Type - Semisubmersible or Drillship Attached is a copy of the subject plan. It has been deemed submitted as of this date and is under review for approval. Ronald O'Connor Plan Coordinator Shell Offshore Inc. P. O. Box 61933 New Orleans, LA 70161-1933 United States of America Tel +1 504 425 4652 Email [email protected] Public Information Copy November 2, 2020 Ms. Michelle Picou, Section Chief Bureau of Ocean Energy Management 1201 Elmwood Park Boulevard New Orleans, LA 70123-2394 Attn: Plans Group GM 235D SUBJECT: Supplemental Exploration Plan OCS-G 31195, Alaminos Canyon (AC) Block 728 OCS-G 32988, Alaminos Canyon (AC) Block 771 OCS-G 35153, Alaminos Canyon (AC) Block 772 OCS-G 19409, Alaminos Canyon (AC) Block 815 AC 859 Unit No. 754307006 Offshore Texas Dear Mrs. Picou: In compliance with 30 CFR 550.211 and NTLs 2008-G04, 2009-G27, 2015-N01 and BOEM 2020-G01, giving Exploration Plan guidelines, Shell Offshore Inc. (Shell) requests your approval of this Supplemental Exploration Plan to drill twenty- one (21) wells at Alaminos Canyon (AC) area from five drill centers. The Geoscience Earth and Marine (GEMS 2019), Shallow Hazards and Archaeological Assessment, Blocks 727-31, 771- 775, 815-819 Alaminos Canyon Area, Gulf of Mexico, GEMS Project No. 1118-2814, July 22, 2019 was previously submitted to BOEM on September 9, 2020 and assigned Survey No. 24576. This plan consists of a series of attachments describing our intended operations. The attachments we desire to be exempted from disclosure under the Freedom of Information Act are marked “Proprietary” and excluded from the Public Information Copies of this submittal. The cost recovery fee is attached to the proprietary copy of the plan. Should you require additional information, please contact Tracy Albert at 504.425.4652 or [email protected]. Sincerely, Tracy Albert Sr. Regulatory Specialist Public Information Copy Page 1 SHELL OFFSHORE INC. SUPPLEMENTAL EXPLORATION PLAN for OCS-G 31195, Alaminos Canyon (AC) Block 728 OCS-G 32988, Alaminos Canyon (AC) Block 771 OCS-G 35153, Alaminos Canyon (AC) Block 772 OCS-G 19409, Alaminos Canyon (AC) Block 815 PUBLIC INFORMATION COPY NOVEMBER 2020 PREPARED BY: Tracy Albert Sr. Regulatory Specialist 504.425.4652 [email protected] Public Information Copy Page 2 REVISIONS TABLE: Date of Request Sections Affected Date Responded RFI No. 1 11/24/2020 Section 1 WCD lease, CC FF, GG & KK lease lines 11/30/2020 Section 2J – Table 3.1 and well number Section 6 – AC 728S name correction Section 11 – Lease stipulation correction RFI No. 2 12/16/2020 Section 2J – WCD (Proprietary data) 01/20/2021 Section 3 – G&G Maps (Proprietary data) Section 6 – ESR Maps (resolution) RFI No. 3 12/17/2020 Section 1 – API Gravity on Form 137 02/24/2021 Section 1 – BHL Well RR (Proprietary data) Section 8 – AQR spreadsheets verbally rescinded Provided full copy of plan 2/24/2021 RFI No. 4 Section 6 AA-DD 3/16/2021 Provided full copy of plan 3/16/2021 Public Information Copy Page 3 SUPPLEMENTAL EXPLORATION PLAN Offshore, Texas TABLE OF CONTENTS SECTION 1 PLAN CONTENTS SECTION 2 GENERAL INFORMATION SECTION 3 GEOLOGICAL AND GEOPHYSICAL INFORMATION SECTION 4 HYDROGEN SULFIDE - H2S INFORMATION SECTION 5 MINERAL RESOURCE CONSERVATION INFORMATION SECTION 6 BIOLOGICAL, PHYSICAL AND SOCIOECONOMIC INFORMATION SECTION 7 WASTE AND DISCHARGE INFORMATION SECTION 8 AIR EMISSIONS INFORMATION SECTION 9 OIL SPILLS INFORMATION SECTION 10 ENVIRONMENTAL MONITORING INFORMATION SECTION 11 LEASE STIPULATIONS INFORMATION SECTION 12 ENVIRONMENTAL MITIGATION MEASURES INFORMATION SECTION 13 RELATED FACILITIES AND OPERATIONS INFORMATION SECTION 14 SUPPORT VESSELS AND AIRCRAFT INFORMATION SECTION 15 ONSHORE SUPPORT FACILITIES INFORMATION SECTION 16 SULPHUR OPERATIONS INFORMATION SECTION 17 COASTAL ZONE MANAGEMENT ACT (CZMA) INFORMATION SECTION 18 ENVIRONMENTAL IMPACT ANALYSIS (EIA) SECTION 19 ADMINISTRATIVE INFORMATION Public Information Copy Page 4 SECTION 1: PLAN CONTENTS A. DESCRIPTION, OBJECTIVES & SCHEDULE Shell Offshore Inc. (Shell) is supplementing Exploration Plan N-9995, approved October 6, 2017, revision R-6650 approved November 27, 2107, Supplemental S-7893, approved June 15, 2018, and Supplemental S-7905 approved September 28, 2018. This Supplement is needed to add twenty-one new subsea wells to the following leases: OCS-G 31195, Alaminos Canyon (AC) Block 728 OCS-G 32988, Alaminos Canyon (AC) Block 771 OCS-G 35153, Alaminos Canyon (AC) Block 772 OCS-G 19409, Alaminos Canyon (AC) Block 815 The AC859 Unit Contract No. 754307006 expanded effective 10/1/2017. The unit now consists of G19409, G20871, G31194, G31195, G32988, and G35153. The Unit is a producing unit that holds these leases, although they are not all receiving an allocation at this time. The following wells have been drilled in the area to date: Lease Well Plan and Letter Spud date Status API No. No. OCS-G 31195 (AC 728) 1 N 9995 “A” 2017 PA’d 6080540080 OCS-G 31195 (AC 728) 2 R-6650 “B” 2017/2018 PA’d 6080540081 OCS-G 35153 (AC 772) 1 N-9889 “C” 2017 PA’d 6080540079 OCS-G 35153 (AC 772) 2 S-7905 “I” 2019 TA’d 6080540085 This supplemental EP will be for the drilling and completion of twenty-one new subsea wells: Wells, AA – UU. The timeframe to complete the initial drilling activities is an estimate based on the best available information regarding downhole conditions likely to be encountered while drilling each well and are not intended to be a limitation. The well(s) will be drilled/completed and will remain shut-in until they are developed under a future DOCD. If any wells are unsuccessful, they will be permanently plugged and abandoned in accordance with the Bureau of Safety and Environmental Enforcement (BSEE) regulations. The drilling will be between 2022-2030 and there may be some years that AC 772 will have two rigs on location simultaneously (see Section 8). The drilling order of the wells has not been determined at this time. The lease area is 150 statute miles from the nearest shoreline, 343 statute miles from the onshore support base at Port Fourchon, Louisiana and 214 statute miles from the helicopter base at Galveston, Texas. Water depths at the well sites range from ~7,092’ to ~8,779’ (Attachment 1A). The proposed rig will be either a dynamically positioned (DP) semi-submersible (Atwood Condor or similar) or a Drill Ship (DW Proteus or similar); both are self-contained drilling vessels with accommodations for a crew which include quarters, galley and sanitation facilities. The rigs will comply with the requirements in the Final Drilling Rules. The drilling activities will be supported by the support vessels and aircraft as well as onshore support facilities as listed in Sections 14 and 15 of the EP. Shell has employed or contracted with trained personnel to carry out its exploration activities. Shell is committed to local hire, local contracting and local purchasing to the maximum extent possible. Shell personnel and contractors are experienced at operating in the Gulf of Mexico and are well versed in all Federal and State laws regulating operations. Shell’s employees and contractors share Shell’s deep commitment to operating in a safe and environmentally responsible manner. Shell, through its parent and affiliate corporations, has extensive experience safely exploring for oil and gas in the Gulf of Mexico. Shell will draw upon this experience in organizing and carrying out its drilling program. Shell believes that the best way to manage blowouts is to prevent them from happening. Significant effort goes into the design and execution of wells and into building and maintaining staff competence. In the unlikely event of a spill, Shell’s Regional Oil Spill Response Plan (OSRP) is designed to contain and respond to a spill that meets or exceeds the worst-case discharge (WCD) as detailed in Section 9 of this EP. The WCD does not take into account potential flow mitigating factors such as well bridging, obstructions in wellbore, reservoir barriers, or early intervention. We continue to invest in research and development to improve safety and reliability of our well systems. All operations will be conducted in accordance with Public Information Copy Page 5 applicable federal and state laws, regulations and lease and permit requirements. Shell will have trained personnel and monitoring programs in place to ensure such compliance. B. LOCATION See attached location plat (Attachments 1A and 1B) and BOEM forms (Attachments 1C through 1X). C. RIG SAFETY AND POLLUTION FEATURES The rig to be used (Atwood Condor or similar DP semi-submersible or DW Proteus or similar Drill Ship) will comply with the regulations of the American Bureau of Shipping (ABS), International Maritime Organization (IMO) and the United States Coast Guard (USCG). All drilling operations will be conducted under the provisions of 30 CFR, Part 250, Subpart D and other applicable regulations and notices, including those regarding the avoidance of potential drilling hazards and safety and pollution prevention control. Such measures as inflow detection and well control, monitoring for loss of circulation and seepage loss and casing design will be our primary safety measures. Primary pollution prevention measures are contaminated and non-contaminated drain system, mud drain system and oily water processing. The following drain items are typical for rigs in Shell’s fleet. DRAIN SYSTEM POLLUTION FEATURES Drains are provided on the rig in all spaces and on all decks where water or oil can accumulate.