UNITED STATES GOVERNMENT November 23, 2020 MEMORANDUM To: Public Information From: Plan Coordinator, FO, Plans Section Public Information copy of plan Subject: Control # - S-08033 Type - Supplemental Development Operations Coordinations Document Lease(s) - OCS-G17001 Block - 508 Walker Ridge Area OCS-G32690 Block - 464 Walker Ridge Area Operator - Shell Offshore Inc. Description - Subsea wells EE, FF, GG, and HH Rig Type - DP Semi or Drill Ship Attached is a copy of the subject plan. It has been deemed submitted as of this date and is under review for approval. Laura Christensen Plan Coordinator Site Type/Name Botm Lse/Area/Blk Surface Location Surf Lse/Area/Blk WELL/001 G32690/WR/464 6552 FSL, 6412 FEL G17001/WR/508 WELL/BB G17001/WR/508 4483 FSL, 5472 FWL G17001/WR/508 WELL/CC G17001/WR/508 4320 FSL, 5327 FWL G17001/WR/508 WELL/DD G17001/WR/508 4515 FSL, 5435 FWL G17001/WR/508 WELL/EE G17001/WR/508 6491 FSL, 6391 FEL G17001/WR/508 WELL/FF G17001/WR/508 6630 FSL, 6199 FEL G17001/WR/508 WELL/GG G17001/WR/508 6540 FSL, 6192 FEL G17001/WR/508 WELL/HH G17001/WR/508 6515 FSL, 6291 FEL G17001/WR/508 WELL/SN105 G17001/WR/508 4549 FSL, 5398 FWL G17001/WR/508 WELL/SN109 G17001/WR/508 4365 FSL, 5296 FWL G17001/WR/508 WELL/SN110 G17001/WR/508 4368 FSL, 5368 FWL G17001/WR/508 WELL/SN115 G17001/WR/508 4467 FSL, 5436 FWL G17001/WR/508 WELL/SN207 G17001/WR/508 6537 FSL, 6358 FEL G17001/WR/508 WELL/SN208 G17001/WR/508 6618 FSL, 6283 FEL G17001/WR/508 Shell Offshore Inc. P. O. Box 61933 New Orleans, LA 70161-1933 United States of America Tel +1 504 425 4652 Fax +1 504 425 8076 Email: [email protected] Public Information Copy October 20, 2020 Mrs. 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 Development Operations Coordination Document (DOCD/SDOCD) OCS-G 32690, Walker Ridge Block 464 OCS-G 17001, Walker Ridge Block 508 Walker Ridge 508 Unit No. 754306006 Offshore Louisiana Dear Mrs. Picou: In compliance with 30 CFR 550.241 and NTLs 2008-G04, 2009-G27, 2015-N01 and BOEM 2020-G01, giving Development Plan guidelines, Shell Offshore Inc. (Shell) requests your approval of this Supplemental DOCD for commencement of production for four (4) subsea wells (EE, FF, GG and HH) that were covered in SEP S-8014 and the seafloor accessories needed to produce these wells. We are also covering wells for future well work. 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 me at 504.425.4652 or [email protected]. Sincerely, Tracy W. Albert Sr. Regulatory Specialist Public Information Copy Page 1 SHELL OFFSHORE INC. SUPPLEMENTAL DOCD For OCS-G 32690, Walker Ridge Block 464 OCS-G 17001, Walker Ridge Block 508 Walker Ridge 508 Unit No. 754306006 PUBLIC INFORMATION COPY OCTOBER 2020 PREPARED BY: Tracy W. Albert Sr. Regulatory Specialist 504.425.4652 [email protected] Public Information Copy Page 2 REVISIONS TABLE: Date of Request Plan Section What was Corrected Date Resubmitted Public Information Copy Page 3 SUPPLEMENTAL DOCD OFFSHORE LOUISIANA 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 submitting this Supplemental DOCD (SDOCD/plan) for Walker Ridge (WR) Block 508, OCS-G 17001 and Walker Ridge (WR) 464, OCS-G 32690. This plan is requesting to commence production for four subsea wells: EE, FF, GG and HH and for the installation of subsea hardware needed to produce these wells. History: The Stones Phase 1 project consisted initially of a subsea development tied back to a Floating Production Storage and Offloading vessel (FPSO). The drilling and completion of these wells were covered in Shell’s Exploration Plan S-7599. The initial DOCD N-9718 covered the installation of the manifold (Drill Center 1), the FPSO and commencing production of these wells. Plan R-6455 was a revision to exploration plan S-7599 to add a drill ship only. Due to drilling issues observed at Drill Center 1, Shell filed Exploration Plan N-9875 for the drilling and completion of eight additional wells and associated drill center (Drill Center 2) in March 2015. These wells and manifold were covered in SDOCD S-7790. Shell filed SEP S-7948 in March 2019 to drill/complete wells, AA-DD, at Drill Center 1. We then followed up with SDOCD S-7969 in December 2019 for Wells AA-DD to commence production and install seafloor accessories. Shell filed RDOCD R-6967 in April 2020 to update AQR to allow for 2 drillships on location. That plan is pending approval. Shell filed SEP S-8014 in July 2020 to drill and complete 4 subsea wells, EE-HH, at Drill Center 2. This SEP was approved Augest 28, 2020. This DOCD will allow those wells to commence production and install seafloor accessories. The wells that have been drilled to date and are being included for future well work are as follows: Well Name Plan EP Name API Number WR 508 005 (SN105) S-7599 J 6081240095 WR 508 007 (SN109) S-7599 L 6081240099 WR 508 011 (SN110) R-6455 M 6081240110 WR 508 013 (SN207) N-9875 R 6081240117 WR 508 010 (SN208) N-9875 U 6081240104 WR 464 001 N-9875 W 6081240112 WR 508 015 (SN115) S-7948 AA 6081240129 WR 508 014 (SN 213) R-6637 P 6081240123 The following are wells we are carrying forward for future well work (in addition to the wells in this SDOCD): Well Name EP DOCD BB S-7948 S-7969 CC S-7948 S-7969 DD S-7948 S-7969 The Stones Unit area covers Walker Ridge Blocks 464, 507, 508, 509, 551, 552, 553, 596, and 597. The development area is 178 miles from the nearest shoreline, 193 miles from the onshore support base at Port Fourchon, Louisiana, and 221 miles from the helicopter base at Houma, Louisiana. The water depths at the well site ranges from ~9,550’ to ~9,600’. B. LOCATION See attached location plat (Attachments 1A and 1B) and BOEM forms (Attachments 1D through 1P). Public Information Copy Page 5 C. RIG SAFETY AND POLLUTION FEATURES As covered in previous EP/DOCD’s for this project, the rig to be used for future well work with either be a DP Drillship (DW Proteus or similar), or a DP semi-submersible (Atwood Condor or similar), or two drillships (one at each drill center). The rigs, once selected, 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. The drains are divided into two categories, non-contaminated and contaminated. All deck drains are fitted with a removable strainer plate to prevent debris from entering the system. Deck drainage from rainfall, rig washing, deck washing and runoff from curbs and gutters, including drip pans and work areas, are discharged depending on if it comes in contact with the contaminated or non-contaminated areas of the Rig. 1) Non-contaminated Drains Non-contaminated drains are designated as drains that under normal circumstances do not contain hydrocarbons and are mostly located around the main deck and outboard in places where it is unlikely that hydrocarbons will be found. Non- Contaminated drains can be directed overboard or to Non-Hazardous storage tanks. Drains are normally directed to storage tanks and only sent overboard if static sheen test is completed. All drains that have the ability to go overboard are plugged and labeled and are lined up to normally go into Hazardous and Non-Hazardous storage tanks. Any deviation from this requires a Request for Approval Drain Plug Removal Form to be filled out prior to any plug being pulled. The rig’s drain plug program consists of a daily check of all deck drains leading to the sea to verify that their status is as designated.