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SUBSEA AND PIPELINES ENGINEERING

Concept Development
Engineering Design and Analysis
Execution Support
Integrity Management
Decommissioning

CONCEPT DEVELOPMENT

Feasibility, Concept Selection, Pre-FEED Studies

Atteris’ experienced concept engineers will screen and define concepts at an appropriate level of detail for each stage of project definition. A small 1-2 week study might support an exploration well’s economic case. A several months duration Pre-FEED study might assess a wide range of value opportunities before selecting a concept to progress to FEED.

Concept Screening Workshops

Atteris’ wide-ranging concept screening workshops, which tap-in to the combined wisdom and creativity of the client’s team and Atteris’ subject matter experts, ensure that all reasonable design concepts are considered at an early phase of concept definition. Working with client’s team, Atteris can facilitate concept workshops which brainstorm alternatives, perform SWOT analyses, and agree a short-list of concepts for further technical evaluation.

Conceptual Development Layouts

Atteris can prepare concept development layouts ranging from a dimensioned sketch of the new facilities, through to a suite of detailed development layouts, including drill centre layouts and riser approaches for offshore developments, and pipeline alignments for onshore waterway, road, and rail crossings. Atteris’ concept drawings are sufficiently detailed to define key concept differentiators, whilst limiting unnecessary drafting effort which is more efficiently done at a later phase of design, once the concept is better defined.

Analogue Project Review And Benchmarking

Atteris’ collective project experience, and its in-house database of worldwide project data, enables it to identify analogue projects which can give a client better confidence that a proposed concept is technically and economically robust, and ready to proceed to the next project phase.

Subsea Architecture Definition

Good subsea architecture selection depends upon good definition of the constraints. Subsurface and drilling constraints drive wellhead locations, dropped object constraints drive equipment spacing, installation vessel constraints limit equipment sizes, future flowlines corridors constrain the foundation project’s flowlines, spool material selection drives spool sizes, etc. Atteris has “been there and done that” on countless projects, and can consider all of these issues, and many more, to achieve the best life cycle value in its subsea architecture designs.

Subsea- Systems Engineering

Atteris’ study managers are highly experienced in understanding clients’ subsurface (reservoir and drilling) and facility constraints, and collaborating with client’s subsurface teams and facilities teams to optimise project value.

Technical Integration

Atteris’ experience through all phases of a project, from concept through to execution and operation ensures we understand and can identify key technical decisions which require integrating into our concepts to ensure feasibility for future development.

Subsea and Pipeline Preliminary Design

Atteris’ core strengths in Subsea Umbilical Riser and Facilities (SURF) and offshore and onshore pipeline design ensure fundamental engineering areas are fully appreciated during the concept definition phase, resulting in robust, constructible and operational development concept options.

Installation and Construction Strategies

Atteris will always strive for designs with the lowest installed / constructed cost without undue sacrifice of integrity. This is achieved by first understanding the installation vessel / equipment capabilities in the region, and then designing flowlines / pipelines and equipment which are installable by a range of contractors, to ensure competitive installation and construction bids during the execution phase.

Safety & Risk Engineering

Safety in design is a key consideration at all phases of Atteris’ concept design and definition. Atteris can facilitate risk reviews and preliminary HAZID workshops at a concept design level. Atteris study managers are highly experienced in effectively managing specialist safety & risk consultants for the more complex or rigorous assessments and studies such as HAZOPs, subsea consequence modelling, dropped object risk analysis, quantitative risk analysis, safety bow tie diagrams, etc.

Schedule & Cost Estimates

Atteris’ in-house database enables rapid and accurate estimation of subsea developments’ CAPEX, OPEX and execution schedules. Atteris is experienced in working with client’s economic team so that CAPEX and OPEX spend profiles can seamlessly integrate into client’s economic analysis.

Value Improvement Practices

VIP workshops can add immense value to a development during the early design phases. Atteris’ VIP workshops typically would involve key client personnel and Atteris subject experts, and the workshop would systematically:

  • Attain common alignment of the project, and the exact VIP workshop process (project specific)
  • Review critical project drivers
  • Review major development value drivers and seek value challenges as appropriate
  • Identify key project risks
  • Rank new and existing value or risk opportunities
  • Agree follow up action plans and responsibilities

Scope Definition Of Next Design Phase

Once the highest value concept is identified, Atteris can assist its clients to define the scopes of work for the next phase of design which will maximise value, and also prevent value-erosion as the concept matures.

ENGINEERING DESIGN AND ANALYSIS

Flow Assurance

Atteris’ flow assurance capabilities include:

  • Fluid sampling and offshore testing program definition, in advance of an exploration or appraisal well
  • Fluid laboratory testing program definition
  • Fluid characterisation (PVTSim or Multiflash)
  • Flow assurance strategy selection, considering all aspects such as liquids management, hydrate management, wax, emulsions, asphaltenes, scale, etc.
  • Subsea processing process design (HYSYS)
  • Steady state and transient multiphase pipeline modelling (PIPESIM / OLGA).
  • Preparation of operating procedures.

Materials Engineering

Atteris has in-house expertise to assist our clients with a range of material selection/assessment issues and their protection against corrosion and erosion associated with subsea and onshore pipelines and related structures. Depending on the complexity of the subject, Atteris will engage recognised subject matter experts as required. This approach has proven to deliver the best results.

Our engineering expertise includes:

  • Materials selection and engineering, including  non-metallic, carbon steel and corrosion resistant alloys linepipe
  • Corrosion and erosion assessments
  • Welding engineering
  • Internal and external coating systems for flow assurance, corrosion prevention, insulation, weight coating
  • Cathodic protection design and assessments
  • Specifications and datasheets

Subsea System Technical Integration

Systems Engineering considers the entire development’s performance, from the reservoir through to the cargo offtake, and ensures that each major system element remains fully integrated throughout the asset lifecycle. It can prevent the enormous costs associated with under-designed or over-design of an element, relative to the greater system.

Atteris’ Systems Engineering approach is to:

  • Maintain overall Safety and risk engineering oversight, with a particular focus on issues across system element boundaries, where a “cause” in one system element might result in a consequence in another system element designed by another engineering team.
  • Actively coordinate inter-discipline engineering (e.g. subsurface-subsea, or subsea-topsides, or topsides-onshore, and the like.)
  • Actively coordinate interface engineering between design teams and between major system elements
  • Consider the full asset lifecycle, to ensure system elements aren’t relatively under or over designed at various stages of asset life

Pipeline Route Survey Support

Atteris has a long track record of supporting our clients with any type of route survey for pipelines, flowlines, umbilicals and cables, including:

  • Survey plans and strategies
  • Planning, cost estimating
  • Scopes of work and specifications
  • Project management and contract administration
  • Offshore and onshore survey support including shore and waterway crossings
  • Geophysical and geotechnical surveys

On multiple projects, an experienced and competent engineer was present on the survey vessel with the necessary computer hardware and software to support the client, and to assist selecting and narrowing down pipeline route options.

Pipeline Route Selection

Analysis selecting the most cost-effective route for pipelines, umbilicals and cables is arguably one of the most important decisions for your pipeline design for both offshore and onshore. Atteris employs engineers with the necessary expertise to select the best possible route for your assets.

Metocean, Geological and Geotechnical Assessments

Atteris has the in-house capabilities to undertake most metocean, geological and geotechnical engineering-related work. Atteris employs engineers with significant expertise in effectively managing specialist consultants in these fields for the more complex assessments and studies in these disciplines.

Pipeline Mechanical Design

Atteris has the capability and experience to perform mechanical design for all aspects of pipeline systems including:

  • Onshore and offshore pipelines
  • All pipeline sizes from large diameter trunklines to small diameter flowlines
  • Deep and shallow water
  • End connections including tie-in spools and risers
  • Design in accordance with various codes including DNVGL, API, AS and ASME
  • Materials selection and engineering, including  non-metallic, carbon steel and corrosion resistant alloys linepipe, welding engineering, internal and external coating systems for flow assurance, corrosion prevention, insulation, weight coating
  • Cathodic protection systems (impressed current and galvanic anode systems).
  • Engineering criticality assessments (ECAs)

Pipeline Stabilisation Design

Atteris has pioneered a large number of innovative hydrodynamic stabilisation designs and methodologies for pipelines and related infrastructure, such as:

  • On-bottom stability engineering assessments taking into account seabed instability processes such as scour and liquefaction
  • Secondary stabilisation designs using rock bolts, rubble mound structures (rock berms) and gravity anchors
  • Pipeline sheltering using pre-trenching and post trenching techniques

Between 2006 and 2010, Atteris, in conjunction with the University of Western Australia (UWA) and with support from Woodside Energy, pioneered the development of a more realistic pipeline on-bottom stability methodology, which takes into account the often complex seabed material local scour and liquefaction processes along pipelines. As part of a project, which assessed the hydrodynamic stability of a large diameter gas trunkline, Atteris convinced Woodside and UWA to undertake large scale model testing as a world first, to simulate the complex interaction between the movement of the water, the pipeline and the seabed material. This resulted in the development, construction and commissioning of the O-tube laboratory testing facility, which has been used multiple times since by Atteris to simulate the behaviour of pipelines, flowlines, umbilicals, rock berms, and concrete and steel mattresses under extreme hydrodynamic loading.

Pipeline Impact Protection Design

Atteris develops cost-effective external impact protection designs and methodologies for pipelines and related infrastructure. Our expertise includes:

  • Quantitative Risk Assessments (QRAs)
  • Dropped object studies using deterministic as well as probabilistic methods
  • Protection designs based on trenching, burial, rock dumping concrete mattresses

Pipeline Global and Local Buckling Mitigation and Response

Atteris has engineering professionals with the ability to undertake global and local buckling analysis and mitigation system design for pipelines. High level study is performed to determine susceptibility of pipelines and flowlines to buckling followed by evaluation to determine if a buckling mitigation strategy is required. Designs consider through life changes in reservoir performance and transient operating procedures with respect to ongoing IMMR costs. Atteris is experienced in the use of the latest design tools and methodologies, including SAFEBUCK and similar in-house developed verified numerical models.

Dynamic Risers

Atteris has in-house engineering expertise for all types of dynamic risers including:

  • Flexible Risers
  • Steel Catenary Risers (SCRs) and variations including lazy wave SCRs
  • Umbilicals
  • Cables

Atteris has expertise in performing quasi-static analyses for early screening work, global dynamic analysis (extreme, fatigue, interference) for detailed design of dynamic riser systems and ancillary equipment as well as offshore installation and operations support including definition of lay tables and maximum allowable sea states for installation/recovery campaigns, design validation and verification.  We can also perform industry benchmarking to provide clients with a simple understanding of where the proposed riser design sits with regards to industry limits of water depth, pressure and ID.

Shore Crossings

Atteris is the recognised leader for the design of shore approaches and shoreline crossings in Australia since 1999, and has left a legacy of innovative and cost-effective designs, based on conventional open cut and cover, horizontal directional drilling and tunnelling. Well known projects, many of which have won an Engineering Excellence Award from The Institution of Engineers Australia, include: TSEP, Otway Gas Project, Gorgon, Wheatstone, Pluto, Reindeer/Devil Creek, Macedon, Alkimos (ocean outfall), Cliff Head, to name a few. Outside of Australia, Atteris has been involved in the design of shore crossing projects in New Zealand, Indonesia, Taiwan, Singapore, and the USA.

Subsea Structures

Atteris’s engineers can perform basic design of subsea structures, including in-line tee structures, PLEMs and PLETs and manifolds. Piping stress analysis is performed in-house. Atteris has expertise in effectively managing specialist structural design consultants for the more complex assessments and studies such as detailed structural analysis (SACS or GTStrudl software) and 3-D drafting (3D CAD or Solidworks).

Trenchless Technology

Atteris is an internationally recognised engineering industry leader in the field of trenchless technology applications in onshore pipeline/cable routes and for pipeline/cable shore crossings, including:

  • Horizontal directional drilling (HDD)
  • Tunnelling and pipe-jacking for pipeline and cable infrastructure

Atteris applies its unique independent and un-biased approach when selecting the best method for any crossing situation, be it open cut and cover, horizontal directional drilling or tunnelling. Atteris is the author of the Engineering Guideline for Shoreline and Waterway Crossings.

Analysis Tools

Atteris uses an impressive suite of licenced engineering computer software packages to support its engineering analysis and decisions, including:

  • ABAQUS, a Finite Element Analysis package used for the modelling of sophisticated engineering problems involving statics, dynamics, multibody systems, impact, nonlinear statics, thermal couplings and the like
  • SAGE PROFILE 3D is a powerful finite element software used for the design and analysis of subsea pipelines. The software is capable of pipeline route simulation and optimisation, bottom roughness analysis, simulation of the pipe-laying process, on-bottom pipeline stress calculations, prediction of lateral and upheaval (global) buckling, evaluation of internal and external forces on pipelines and free span evaluation.
  • AUTOPIPE is a piping, spool, and riser design and analysis software that incorporates the guidelines and design limits of DNVGL, ISO, ASME / ANSI, API and other international design codes.
  • FLEDERMAUS is a 4D geo-spatial processing, mapping and pipeline routing analysis tool used to interact with large geographical datasets, and numerous data types, from bathymetry surveys. FLEDERMAUS is used on board survey vessels to assure datasets at near realtime speeds, plan base and alternate survey scopes, and perform preliminary pipeline routing for feasibility during route surveys. FLEDERMAUS is also used in the office environment to perform comprehensive route evaluation and selection studies which assess straight forward flat seabeds to difficult pipeline routing through geohazard like continental scarp crossings and / or debris flows. Pipeline route x,y,z data can also be exported to software for on-bottom roughness (pipeline stress) assessment leading to routing changes as required. The software is also capable of developing presentations which fly along the pipeline to assist in stakeholder engagement and route visualisation.
  • CORUS 3D is an Atteris proprietary finite element analysis software used for the on-bottom stability assessment of subsea pipelines, flowlines, umbilicals and cables under wave and current loading over time. This dynamic on-bottom stability analysis software has been wholly developed by Atteris and has since been independently analysed and validated by DNV-GL. CORUS 3D is a powerful software package which has a track record of delivering reliable, robust and cost-effective engineering designs for subsea pipelines.
  • PROBED allows for the conceptual design of static and dynamic engineered rock structures or berms that are used for scour protection, foundation beds, pipeline secondary stabilisation, and pipeline protection. The software allows for the inclusion of external loading on the rock structures from steady currents and oscillating currents induced by non-breaking waves. PROBED uses empirical and semi-empirical design equations based on wave height, Shields parameter, shear stress and other inputs to calculate a hydrodynamically stable D50 rock particle size. PROBED can be used in both the conceptual design of top layer rock to resist hydrodynamic loading and filter layers to protect structures from damage by the larger top layers or provide a foundation bed in weak seabed material.
  • ORCAFLEX is a 3D non-linear time domain finite element program that provides fast and accurate analysis of dynamic offshore marine systems under wave, current, and externally imposed loads including vessel motions. Orcaflex is capable of dealing with large deflections and can perform installation and in-place analysis. It is used for the analysis of risers (Steel Catenary Risers (SCRs), Hybrids, tensioned), umbilicals, flexibles, hoses, cables, moorings, towed systems (pipelines, bundles), pipelay, cable lay, through splash zone deployment, dynamic lifts, J-tube pull-ins and pull-outs, and stab and hinge simulations and more.
  • ABAQUS CFD is a Computational Fluid Dynamics package for the the modelling and assessment of nonlinear coupled fluid-thermal and fluid-structural problems. Modelling of laminar and turbulent: internal or external flows that are steady-state or transient, span a broad Reynolds number range, and involve complex geometry is all within the software’s capabilities. Atteris uses Abaqus CFD for the assessment of subsea heat exchanges to determine efficiencies in design as well as hydrodynamic coefficients for complex structures and increases in shear stress due to flow amplification.
  • D-GEO enables the design of trenchless pipeline installation such as micro-tunnelling and horizontal directional drilling. It allows for the input of geotechnical conditions to complete soil spring models around the pipeline for analysis of arching and settlement effects on the pipeline as well as stresses in the pipeline and casings during the installation stage.
  • PDAM Atteris is a Joint Industry Partner of the Pipeline Defect Assessment Manual (PDAM). PDAM presents the best methods and tools available in industry for the assessment of pipeline defects. Defect types that are considered in this manual include corrosion, gouges, dents (plain, kinked and smooth), manufacturing defects, girth and seam weld defects, cracking and environmental cracking. The manual provides guidance for single and interacting defects, and considers whether the defect is longitudinally or circumferentially orientated.

Health, Safety and Environmental

Atteris applies highly effective systems in its work to protect the safety and health of its staff and general public, and the care of our natural environment.

The adopted culture is Behavioural Based Safety (BBS), which is an approach that focuses on employee’s behaviour as the cause of most work-related injuries and illnesses. It is based on solid principles about engaging, motivating, assisting, reinforcing, and sustaining safe behaviours. It is an ongoing effort by all but comes with the reward of working in an environment that truly values the safety of all individuals, sees no boundaries, and everyone is considered equal. The aim of BBS is to create a safety culture within the workplace; ensuring the safe performance of duties through genuine care and respect for one another.

  • A safety culture is a culture in which:
  • Individuals hold safety as a value and not just a priority
  • Individuals take responsibility for the safety of their co-workers in addition to themselves
  • All levels of employee are willing and able to act on their sense of responsibility.

An efficient and effective in-house developed “HSE-in-engineering” procedure supports all our work, assuring our services result in cost-effective, safe and sustainable engineering solutions.

EXECUTION SUPPORT

Safety and Risk Assessments

Atteris support’s its clients in performing safety and risk assessments (HAZOPS / HAZIDS) related to our designs and the associated construction activities, or as a consultant to your designs and operations. We have a proud track record of considering safety and risk in design and striving to maximise the inherent safety and demonstrate certainty in risk of the designs we produce. Our knowledge and experience of design, construct, and operated (IMMR) is a valuable asset to these processes.

Support to Project Approvals

Atteris has a long track record in effectively supporting project developers with environmental and regulatory approvals. Engineering support can be provided for:

  • Offshore and onshore environmental impact statements
  • Sea dumping permits
  • Consent to construct applications
  • Right of Way (ROW)
  • Safety cases
  • Attendance at meetings with government and regulators
  • Pipeline licenses

Package Management and Project Engineering

Atteris has engineering professionals with significant expertise in project management and construction support. This includes:

  • Development of tendering and contracting strategies
  • Preparation of ITT documentation, such as contracts, pricing schedules, scopes of work, specifications and drawings
  • Review of tender submissions
  • Package management, project management, contract administration and construction supervision
  • Project close-out reports

Installation Analysis

Atteris has in house expertise and software to perform installation analysis for pipelay, flexlay, umbilical lay, pull-ins, pull-outs, pipe-push, mechanical connection make-up, structure deployment etc. As well as performing high level studies to confirm installability of proposed designs in the early stages of projects, Atteris has on a number of occasions performed detailed installation analysis on behalf of construction and installation contractors.

Cost and Schedule Estimates

Atteris has advanced systems, comprehensive cost and schedule database and significant expertise in relation to the preparation of cost estimates and schedules for pipeline projects. Cost estimating and schedules can be performed deterministic as well as probabilistic, taking into account design, construction and fabrication, and commercial risks.

Construction Support

Atteris has a successful track record of supporting our clients in the field during construction activities, in particular where this involves overseeing the construction and / or installation of Atteris designed solutions. We have a firm belief that this serves the client in ensuring that no aspect of the design is overlooked in the construction stage, while also exposing our engineers to field operations and thus constantly improving our ability to ensure our designs can be efficiently constructed and installed.

Construction Method Development and Review

Construction and execution experience is a valuable part of a design engineer’s development. At Atteris we recognise this fact and have made this part of our development program for our engineers. Most of our engineers have a strong construction background, which we draw upon to develop and review construction methodologies, often running internal workshops to ensure the most constructible designs. Understanding construction methodologies early in your project phases will reduce risk of cost and schedule overrun during execution, maintaining project value.

Regulatory Compliance

Atteris understands Regulatory Compliance and can assist / manage the assembly of evidence required to demonstrate compliance in addition to performing engineering assessment as required. Atteris also has expertise in effectively managing regulatory compliance specialists for more complex submissions.

INTEGRITY MANAGEMENT

IMMR Engineering and Support

Inspection, Monitoring, Maintenance and Repair (IMMR) activities are cornerstone to successful risk management of offshore and onshore infrastructure. Risk based IMM plans and practical Emergency Response and Repair plans and procedures facilitate effective management of risk. We take a holistic and practical approach to IMMR engineering that considers project and location specific variables, operational constraints and system interdependences, and stage in the asset lifecycle.

Risk Assessments

The key to maintaining integrity of offshore and onshore infrastructure is through understanding credible risks to the system. Our holistic, practical and systemic approach to risk assessment returns a technically sound and realistic output. Our approach also considers the stage in the asset lifecycle. This is forms the foundation of an effective integrity management program to manage the risks, and one that maximises economic recovery without compromising on health, safety or the environment.

Integrity Management System Design

An effectively designed and implemented integrity management system is the backbone to successful management of offshore and offshore infrastructure. Our practical approach takes into account the policies and philosophy of your operations, available systems and resources, and stage in the asset lifecycle. The focus is on delivering a system that addresses the organisations key drivers, considers constraints of the organisation, project or operating location.

Intervention and Retrofit Design

Intervention and retrofit design includes design for retrofit or repair, to restore or modify the functionality of your offshore or onshore infrastructure. We deliver bespoke, practical engineering solutions that fit our client’s key drivers. Our practical solutions have consistently proven to deliver cost, time or risk reduction to our clients. We are able to develop intervention and retrofit designs from concept through to detailed design and provide project engineering support for execution. Our holistic through-life approach ensures that the design solution is practical to implement and can be inspected, monitored and maintained.

Fitness for Service Engineering

During the operational life of an asset, IMM activities will return condition and anomaly data. Our approach to fitness for service engineering assessment is focused on determining whether integrity could be compromised and defining action that needs to be taken. Remaining life assessments can be performed to establish a timeline for proactive response and adequate anomaly monitoring strategy. Atteris are JIP members of the Pipeline Defect Assessment Manual (PDAM), giving access to global best practices and software tools to carry out these engineering assessments.

Life Extension Assessments

Life extension assessments, also known as design requalification assessments, comprise of a full integrity review of your offshore or onshore asset at the end of its design life. The purpose of these assessments is to demonstrate fitness for continued service. Our approach best practice international guidelines for the process and a bespoke approach for assessing integrity depending on the current condition of your asset, its operating history and projected operating requirements. Each asset is unique and understanding credible and relevant risks is fundamental to minimising business exposure. Even for assets with minimal data, Atteris can help to realise your life extension needs.

DECOMMISSIONING

Offshore Pipeline Decommissioning Engineering Guideline

Atteris wrote the Offshore Pipeline Decommissioning Engineering Guideline for the Energy Pipelines Cooperative Research Centre (EPCRC). The guideline was developed in consultation with the Decommissioning Committee established by the Australian Petroleum Production and Exploration Association (APPEA).

Decommissioning Studies

At the end of an asset’s lifecycle, decisions around decommissioning must be made. To facilitate the decision making process, decommissioning studies can be performed to guide your operations through the technical, commercial and regulatory requirements for decommissioning options. Atteris provides the needed engineering support for decommissioning concept studies and methodologies, cost and schedule estimations, and onshore and offshore project engineering support through to completion of decommissioning works. Our approach is to focus on maximising economic recovery without impacting on health, safety or the environment.

Decommissioning Engineering and Support

Atteris provides engineering and project management services to help you realise your decommissioning projects. We provide engineering support for project planning, safety case and environmental plans, engineering for in-situ, suspension and recovery options, development of plans and procedures, risk assessment workshops, environmental studies, cost and schedule estimates, project management services in relation to tender and offshore contractor management and engineering support during execution. Our approach is to focus on ensuring the project is executed as planned without impacting on health, safety or the environment.