DECOMMISSIONING PLANNING V-COMM PACKAGES

Vertech’s V-COMM Decommissioning Package was formed to support the full decommissioning cycle. Providing a collection of specialist services, systems, processes, and products, Vertech's experts will work alongside each client to achieve environmental & safety excellence, reduce cost through efficiency, and exceed all regulatory requirements.

The Australian offshore petroleum industry has been in operation since the early 1960s. As the sector continues to mature, an increasing number of offshore petroleum projects across the APAC region are reaching the end of their productive lives. It is anticipated that a substantial number of the approximately 136 fixed facilities (including pipelines) are likely to commence decommissioning activities in the coming decade.

Each piece of infrastructure can present its own unique decommissioning challenges due to the combination of infrastructure type and its location in the surrounding environment. Major offshore infrastructure that requires decommissioning at the end of a project include:

  • Surface infrastructure – concrete and steel platforms including topsides and jackets
  • Pipelines – trunk lines, rigid flow lines, flexible flowlines, umbilicals
  • Risers and turret moorings
  • Floating installations – floating production facilities (FPSOs)
  • Subsea systems – wellheads, production modules, anchors, CGSs, mattresses

Decommissioning Planning

The foundations of a successful decommissioning project are built through detailed planning and early engagement with both regulatory bodies and specialist contractors relevant to each phase of the decommissioning cycle. This early engagement ensures a comprehensive and shared understanding of the specifics of the Well Management Plan (WMP), Field Management Plan (FMP), Environmental Plan (EP), Safety Case (SC) and how this framework combined with the specific state regulatory requirements/bodies will impact each phase of the decommissioning cycle.

From environmental, topside and subsea engineering through to implementation management, Vertech Group has a wealth of experience and skills that can provide critical services throughout the comparative risk, cost, environmental and regulatory approval phases. Our team also have the understanding to most effectively utilise the tacit knowledge gained in these early stages, using it to improve the support, selection and implementation of the final decommissioning methodology.

  • Environmental engineering
  • Project engineering
  • Technical services
  • Integrated activity planning
  • Site survey & assessment
  • Rigging and lift planning

Topside or Disconnect Preperation

Before the full decommissioning process can be undertaken the platform, FPSO or asset, must be prepared. This is a crucial preparatory phase in the decommissioning cycle, and it is at this phase that Vertech Group's multi-disciplined, high-mobility, inspection and maintenance teams can provide maximum value. For offshore platforms, the infrastructure's integrity needs to be carefully surveyed and understood in anticipation of major lifting operations. Simultaneously, the assessment, planning, and execution of major plant and machinery removal is required to ensure environmental protections are in place. When it comes to floating assets, major module lifts are unlikely, so the campaign's principal focus shifts to hull structural integrity for towing operations, removing machinery, and disconnecting critical systems (electrical, hydraulic, etc.).

Examples of Vertech Groups topside or disconnect specialisations include:

  • Premobilisation training and mock-ups
  • Inspecting and surveying primary, secondary or marine structures
  • Inspection of process and plant equipment’s structural integrity
  • Inspecting, NDT, proof load testing, and installing lifting points
  • Access management & planning
  • Preparing detailed rigging and lift plans
  • Building detailed safe work method statements
  • Rigging, lifting and removal of anything not part of the primary structure
  • Cutting and mechanical services to remove piping and tertiary steelwork
  • Removal and cutting of cables between deck modules
  • Subsea inspection of marine growth, hull, and jacket structures
  • Subsea infrastructure surveying – Mini-ROV and Autonomous Underwater Vehicle survey
  • Subsea marine environmental baseline inspections

Topside & Jacket or Disconnect Support

The topside and jacket removal is the largest cost and risk to the decommissioning cycle. Dependent on the selected decommissioning methodology, almost two-thirds of the total decommissioning costs can come from the removal, making it imperative to have the right tooling and specialists to minimise delays and provide dynamic support.

FPSO disconnects are significantly quicker with a lower risk and cost profile in comparison to platforms. The disconnect phase involves disconnecting the production risers, umbilicals, and mooring chains from the FPSO for its sail away, followed by the careful removal and disposal of the turret mooring system and subsea infrastructure.

  • Access management & planning
  • Preparing detailed rigging and lift plans
  • Building detailed safe work method statements
  • Major lift rigging and lifting implementation
  • Cutting and mechanical services
  • Subsea / topside live visual feed through ROV systems

Post Commissioning Monitoring

Decommissioning activities are regulated through the submission and approval of revised Field Management Plans (FMP), Well Management Plans (WMP), Environment Plans (EP) and Safety Cases (SC). Our team of specialists work closely with the asset owner to plan and optimise environmental monitoring (particularly where infrastructure is partially decommissioned or decommissioned in-situ) to confirm that impacts have been reduced to ALARP. Through our subsidiaries in Geo Oceans and Blue Ocean Marine Services, Vertech Group are able to offer asset-deployed or vessel of opportunity Mini-ROV systems and industry-leading Autonomous Underwater Vehicle (AUV) systems for detailed and comprehensive post decommissioning monitoring.

Geo Oceans has set a new standard in survey efficiency and data quality by performing a range of real-time data analysis and processing tasks in the field. Our ROV systems and towed cameras combine with our GO Visions™ software, allowing us to create fine-scale habitat maps across large areas, far more accurately and efficiently than previously possible. The data collected allows us to provide fish surveys to millimetre accuracy and bathymetry survey data for mapping marine habitats.

Geo Oceans specialise in:

Blue Ocean Marine Services have a sound understanding and unparalleled experience of the offshore regulatory environment relating to the early site appraisal and late field decommissioning cycles. Blue Ocean Marine services bring together a fleet of industry-leading light Autonomous Underwater Vehicle (AUV) technology, marine scientists, specialist tooling, sensors, and cutting-edge software to provide fully autonomous subsea post decommissioning monitoring and survey packages.

Blue Ocean Marine Services specialise in:

  • Real-time statistical data processing to check the data meets requirements
  • Stereo images allow accurate size measurements
  • Scour monitoring
  • Production of fine-scale subsea maps (in real-time)
  • HD still imagery and video footage with real time data transfer
  • Passive Acoustic Monitoring (PAM)
  • Water and sediment sampling / testing
  • Scour monitoring
  • Environmental and ecological surveys
  • Meteorological and oceanographic surveys
  • Benthic habitat mapping

CASE STUDIES

RTM DECOMMISSIONING

Vertech was contracted to assist with the decommissioning of a Riser Turret Mooring (RTM) from a disconnected FPSO. The Project required detailed front-end planning to access the structure, survey it using Remote Digital Visual Inspection (RDVI), and use NDT to confirm the RTMs internal watertight structures' integrity. The Project was delivered safely, under budget, and the acquired inspection results played a crucial part in the overall program.

NRA DERRICK DECOMMISSIONING

Vertech was engaged by Woodside energy to decommission the North Rankin Alpha drill derrick while the platform was operational. Vertech provided; planning, engineering and technical services for eight months prior to execution; completed onshore mock-up trials; and managed full implementation of multi-disciplinary inspection, craft and rope access personnel to complete this challenging project successfully.

CHERVIL PLATFORM

Fugro engaged our team to provide rope access, welding and rigging solutions to remove Quadrant Energy’s Chervil Facility, following the end of its economically viable production life. Due to the facility being located in a Class A nature reserve, the team put a particular focus on environmental safety, ensuring all work complied and exceeded any applicable regulations.

GWA DERRICK DECOMMISSIONING

Vertech was engaged to decommission the Goodwyn Alpha (GWA) drill derrick while the platform was in production. Vertech provided its full suite of engineering, technical services and site surveys throughout the planning phase. The implementation phase required multi-disciplined rope access inspection, mechanical, electrical, and advanced rigging personnel to complete the project on time, within budget and with a perfect safety record.

NGANHURRA FPSO DISCONNECT

Vertech provided multi-disciplined marine class inspectors, NDT inspectors and lifting engineers to confirm the integrity of critical structures required for the disconnect and tow. Simultaneously, over multiple campaigns, our maintenance and IRATA rope access personnel (including mechanical fitters, EEHA inspectors and riggers) prepared the asset for the FPSO disconnect and ultimate decommissioning phase.

NE FPSO DECOMMISSIONING PLANNING

Vertech was engaged by Woodside to conduct thorough inspection & integrity assessments as part of the decommissioning assessment phase. This included work on items such as facility fixed lifting points & structures, fairleads, main sheaves & handling tables, riser winch assemblies, turret main winches, riser hook-up pulling boom boxes and the primary marine structures.

Capability Statement

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