METHOD STATEMENT Installation of Subsea Pipeline Tie-in at Existing Offshore Platform Project: Mumbai High Offshore Field – ONGC Contractor: Marine EPC Solutions Document Type: Method Statement 1.0 Purpose 1.1 This Method Statement defines the engineering methodology, offshore construction sequence, quality assurance measures, HSE requirements, marine operations, and commissioning philosophy for the installation and subsea tie-in of the proposed pipeline to the existing offshore platform in Mumbai High at an approximate water depth of 60 metres. 1.2 Marine EPC Solutions shall execute all offshore activities in accordance with the Contract Specifications, approved construction procedures, statutory regulations, and applicable international offshore engineering standards while ensuring safe integration with existing production facilities and uninterrupted operational coordination with ONGC. 2.0 Applicable Codes, Standards and Specifications 2.1 All offshore pipeline construction activities shall comply with the latest applicable editions of: API RP 1111 – Design, Construction, Operation and Maintenance of Offshore Hydrocarbon Pipelines API 1104 – Welding of Pipelines and Related Facilities ASME B31.8 (where applicable for gas service) and relevant offshore pipeline specifications DNV-ST-F101 – Submarine Pipeline Systems DNV-ST-N001 – Marine Operations and Marine Warranty NACE MR0175 / ISO 15156 – Materials for H₂S (Sour Service) Environments where applicable NACE SP0169 – Cathodic Protection of Submerged Metallic Pipelines IEC 61892 – Mobile and Fixed Offshore Electrical Installations IMCA Guidelines for Offshore Diving Operations IMO SOLAS Requirements International Regulations for Preventing Collisions at Sea (COLREG) ONGC Offshore Safety Regulations and Permit-to-Work Procedures 3.0 Engineering Preparation 3.1 Detailed engineering shall include verification of existing platform tie-in arrangements, subsea survey data, bathymetry, metocean conditions, and pipeline alignment. 3.2 Engineering analyses shall include: Installation analysis Pipeline stability assessment Free-span assessment Hydrodynamic loading analysis Tie-in spool design Installation stress analysis Lifting analysis Seafastening verification Temporary works design 3.3 Installation drawings, lifting procedures, dive plans, marine spread documentation, and contingency procedures shall be submitted for Client approval before mobilisation. 4.0 Marine Mobilisation 4.1 Marine spread mobilisation shall include installation barges, anchor handling tugs, diving support vessel, ROV support vessel, cargo barges, and utility vessels as required. 4.2 All marine equipment shall possess valid certification and inspection records. 4.3 Vessel positioning systems shall be calibrated before offshore operations. 4.4 Marine exclusion zones shall be established around the work location. 5.0 Offshore Construction Methodology 5.1 Pre-Lay Activities Marine route verification Pre-lay ROV inspection Seabed clearance Position confirmation Existing asset identification Crossing verification Installation readiness review 5.2 Pipeline Installation Pipeline installation shall be performed using the approved lay methodology while maintaining allowable installation stresses within DNV-ST-F101 limits. Continuous monitoring shall be carried out for: Lay tension Overbend Sagbend Vessel position Weather conditions Dynamic loading 5.3 Subsea Tie-in The subsea tie-in shall be executed using qualified offshore diving personnel and/or ROV intervention depending upon operational requirements. Activities shall include: End preparation Alignment verification Dimensional survey Tie-in spool installation Mechanical connection Welding where applicable NDT examination Field joint coating Cathodic protection continuity verification 5.4 Hyperbaric Diving Operations All diving activities shall be executed by DNV-certified diving personnel in accordance with IMCA guidance. A complete Diving Project Plan shall include: Emergency evacuation procedures Saturation diving procedures Decompression schedules Hyperbaric chamber arrangements Medical support Diving communication protocols 6.0 Marine Warranty Survey 6.1 A Marine Warranty Surveyor (MWS) shall review and approve all critical marine operations, including heavy lifts, pipeline installation, subsea tie-ins, transportation, and installation procedures prior to execution. 6.2 Hold points requiring MWS acceptance shall be observed before commencement of critical offshore activities. 7.0 Helideck and Offshore Logistics 7.1 Personnel transfer to the offshore installation shall be coordinated through the platform helideck in accordance with applicable aviation procedures and Client logistics requirements. 7.2 Helideck operations shall comply with CAP 437 and applicable offshore aviation safety requirements. 7.3 Emergency response arrangements shall include helicopter evacuation planning and offshore medical support. 8.0 Quality Assurance and Quality Control 8.1 Marine EPC Solutions shall implement an approved Inspection and Test Plan (ITP). 8.2 Quality activities shall include: Material verification Mill certificate review Welding qualification verification Welder qualification Dimensional inspection NDT examination Holiday testing Coating inspection Cathodic protection testing Final as-built survey 9.0 Health, Safety and Environment (HSE) 9.1 All offshore work shall be performed under an approved Permit-to-Work system. 9.2 A comprehensive Job Safety Analysis (JSA) and Task Risk Assessment (TRA) shall be completed before each critical activity. 9.3 Emergency preparedness shall include: Man overboard procedures Medical evacuation Oil spill response Fire response Diving emergency procedures Cyclone and adverse weather contingency plans 9.4 Environmental protection measures shall ensure prevention of marine pollution and compliance with applicable offshore environmental regulations. 10.0 Testing and Pre-Commissioning 10.1 Following completion of the tie-in, the pipeline shall undergo: Geometry verification Hydrostatic testing Leak testing Cleaning Gauging Dewatering where applicable Drying (if specified) Final integrity verification Client acceptance inspection 11.0 Documentation Marine EPC Solutions shall submit: Daily offshore progress reports Dive reports ROV survey reports NDT records Welding records Pressure test certificates Marine logs As-built drawings Final completion dossier Mechanical Completion Certificate 12.0 Local Content 12.1 Marine EPC Solutions shall maximise the utilisation of qualified Indian manpower, locally sourced materials, approved fabrication facilities, and domestic offshore support services in accordance with ONGC contractual requirements and applicable Government of India local content policies. 13.0 Scope Exclusions Unless specifically included within the Contract, the following activities are excluded: 1. Modification of existing offshore platform process facilities beyond the designated tie-in point. 2. Permanent production shutdown planning by the Operator. 3. Replacement of existing subsea pipelines outside the defined work scope. 4. Supply of Owner-Furnished Equipment (OFE). 6. Long-term operation and maintenance following project handover. 7. Third-party utility relocations not identified in the Contract. 8. Reservoir, production, or process performance studies. 9. Scope gaps commonly missed in offshore O&G tenders 10. Marine Warranty Survey approval hold points. 11. SIMOPS (Simultaneous Operations) management with live platform activities. 12. Weather downtime and metocean criteria. 13. Emergency vessel and standby rescue arrangements. 14. ROV contingency plan in case diving operations are suspended. Compliance checklist (5 offshore-specific clauses) ✓ Compliance with DNV-ST-F101 for submarine pipeline installation. ✓ API 1104 welding qualifications and NDT acceptance criteria. ✓ Marine Warranty Survey approval for critical offshore operations. ✓ IEC 61892 compliance for offshore electrical installations where applicable. ✓ NACE MR0175 / ISO 15156 compliance for any sour-service materials, if required by the process fluid. Winning edge tip for offshore tenders Include a detailed SIMOPS management plan, vessel utilisation schedule, weather-risk mitigation strategy, and proven offshore HSE performance (such as TRIR/LTIF statistics). Demonstrating robust interface management with ongoing platform operations and strong marine logistics planning often improves technical evaluation scores in offshore EPC bids. Follow-up email template Subject Submission of Method Statement – Offshore Subsea Pipeline Tie-in Project Dear Sir/Madam, Please find enclosed our Method Statement for the Installation of the Subsea Pipeline Tie-in at the Existing Offshore Platform in the Mumbai High Field. The document outlines our proposed engineering methodology, offshore construction sequence, marine operations, diving procedures, quality assurance measures, HSE management system, and applicable international codes and standards, including API, DNV, ASME, NACE, IEC, and IMCA requirements. Marine EPC Solutions confirms that all activities will be executed in full compliance with the Contract Specifications, ONGC offshore safety requirements, and approved project procedures. We remain committed to delivering the work safely, efficiently, and within the project schedule while maintaining the highest standards of quality and operational integrity. Should any clarification or additional technical information be required, we shall be pleased to provide the same promptly. Yours faithfully, For Marine EPC Solutions Authorised Signatory