Subsea Asset Integrity Management

The aim of integrity management is to prevent structural, containment and function failures through a structured process which consists of the following items:

  • Threat identification and risk assessments

  • Inspection, testing and maintenance planning

  • Inspection, monitoring and testing (IMT) activities

  • Integrity assessments and investigations

  • Mitigation, intervention and repair

The A60N team has extensive experience in providing integrity management services to Operators, during the entire life from conceptual design to abandonment, in accordance with the following codes:

  • DNVGL-RP-0002 - Integrity management of subsea production systems

  • ISO 13628 - Design and operation of subsea production systems

  • DNVGL-RP-F206 - Riser integrity management

  • API 17J - Specification for unbonded flexible pipe

  • DNVGL-RP-F116 - Integrity management of submarine pipeline systems

  • AS 2885.3 - Pipelines - Gas and liquid petroleum operation and maintenance

Please see below for examples of our previous subsea asset integrity management work. 

Case Studies

Subsea Interface Functionality Review

Scope

Following an equipment operational problem, due to calcareous deposit build up, a field wide SPS interface functionality review was performed.

Services Provided

Review of all interface materials / geometries to assess seize likelihoods. Risk assessment of interfaces with / without mitigations. Mitigations / design modification recommendations.

Benefits

All interfaces were risk ranked to allow the Operator to prioritise mitigation solutions / intervention tooling development

Subsea Pipelines Integrity Review

Scope

An review was performed on a subsea pipeline system to establish its integrity.

Services Provided

Review of internal and external inspection data covering topsides, splashzone and subsea. Review of production data, including: corrosion probe and production chemistry.

Review of valve maintenance and performance records. Review of historical integrity documents. Development of integrity summaries for the pipeline system.

Benefits

The work highlighted integrity status of the system to the Operator and provided maintenance and operation cost estimates to the end of field life.

Flexible Riser and Flowline Integrity Testing

Scope

A flexible riser annulus testing campaign was performed for a client in South East Asia.

Services Provided

Review of two previous riser annulus test reports with conflicting conclusions.

Development of a test procedure. Offshore testing campaign including a vacuum and positive pressure testing and reporting of findings.

Benefits

The testing provided a definitive answer as to the nature of the flooded annulus, allowing the Operator to develop plans for the its continued safe operation. 

SDU Materials and CP Design Reviews

Scope

A design review was carried out for the electrical connectors on a subsea distribution unit (SDU).

Services Provided

The review focused on electrical connector materials, CP system design and electrical isolation methods. Support was provided to site personnel during the electrical harness installation phase.

Benefits

The electrical components were installed in accordance with supplier recommendations, thereby minimising the risk of failure / functionality issues of the electrical connectors and junction boxes.

Subsea and Pipelines - CP Survey

Scope

An offshore cathodic protection survey campaign was supported for a client in the Bass Strait.

Services Provide

Provision of:

  • Subsea engineers;

  • 3.4U inspectors; and

  • CP technician and equipment.

Inspection of pipelines, structures and subsea systems and CP Reporting

Benefits

The client was provided with the external integrity status of their subsea assets including; pipelines; jacket structures and subsea production system.

 

Testing and Materials

A60N provides bespoke testing and materials services to our clients to help them understand the performance of equipment and materials such as metals, coatings and polymers under various hostile conditions.

A60N has relations with various commercial laboratories, university research centres coupled with access to offshore and onshore test facilities to perform representative tests and obtain results for clients.

Test results aid in key decision making regarding subsea asset design and operation.

Case Studies

SCM Electrical Connector Testing

Scope

A subsea control module (SCM) was stuck in a partially disconnected state, and prolonged acid cleaning was proposed to aid in the recovery of the SCM.

Services Provided

Two bespoke tests were developed to establish if acid cleaning could be carried out on the SCM / SCMMB interfaces and for how long. Three electrical connectors were set up to represent the partial disconnection and soaked in the cleaning fluid for various durations. Insulation resistance (IR) checks were conducted throughout the test duration to establish any IR deterioration. Tests were also conducted on a connector fully immersed in the acidic cleaning fluid.    

Benefits

The positive outcomes of the testing scope allowed the Operator to conduct the cleaning scope with the necessary exposure time to remove the SCM.

Electrical Connector Material Testing

Scope

Testing was required to establish the allowable acid exposure times for a variety of electrical connector polymers.

Services Provided

A test program was developed to conduct a series of acid immersion tests on a variety of electrical connector polymer materials. Disassembly of connectors was performed to obtain the required materials. Following set periods of acid exposure mass, volume, hardness and tensile tests were conducted. Microscopy was also utlisied to check surfaces for any signs of deterioration. 

Benefits

The testing program allowed safe subsea acid soaking durations to be established for a variety of interventions

Calcareous Deposit Cleaning Efficiency

Scope

A testing program was conducted to benchmark commercially available cleaning products in relation to removing calcareous deposits subsea.

Services Provided

A program was developed to test the effectiveness of five calcareous deposit cleaning products for use subsea. Effectiveness was tested on deposit samples recovered from subsea and pellets produced from the recovered deposits. Test pellets were also produced from CaCO3 and Mg(OH)2 powders, and mixtures thereof, in order to quantify the efficiency of the various acids with varying deposit Mg(OH)2 content. The effects of acid dilution by seawater were also tested. 

Benefits

The testing program provided an extensive knowledge base for the selection of an optimum subsea calcareous deposit cleaning product. 

Super Duplex Stainless Steel HISC Testing

Scope

Testing was conducted to quantify the effects of hydrogen on the structural properties of swaged super duplex stainless steel (UNS32760).

Services Provided

A comprehensive testing program was developed and performed to establish the effects of hydrogen evolved from the subsea sacrificial cathodic protection system on swaged SDSS. The scope included: Chemical and microstructure analysis; Fractographic examination; Total hydrogen content testing; Hardness profiling; Corrosion resistance testing and Tensile testing.  

Benefits

Recommendations were developed for the use of swaged super duplex stainless steel (UNS32760) in subsea applications.

Subsea Bolt Corrosion and Coatings Testing

Scope

Bolts used subsea frequently suffer from coating breakdown, corrosion and subsequent seizing / bolt failure.

Services Provided

Bolts with a number of different surface treatments were tested subsea. The tests were run for 6 months, and the bolts were monitored utilising a subsea camera powered from shore during the test period. The testing was conducted locally off the coast of Fremantle, thereby providing similar temperatures and salinity conditions to those observed for typical Australian subsea developments.

Benefits

The extensive test program allowed a knowledge base to be developed regarding the performance of a variety of bolt materials and coatings when exposed to harsh subsea conditions.

 

Failure Investigations

A60N provides failure analysis services to our clients in a structured manner through a variety of methods such as: fault tree analysis (FTA), failure modes, effects and criticality analysis (FMECA), Ishikawa / fishbone diagrams and 5 whys.

Following initial review work an appropriate testing plan would be developed, typically consisting of a variety of destructive and non-destructive tests to identify the root cause of failure.

Once the cause of failure has been identified plans can be developed to mitigate future occurrences, and/or improve future designs. 

Case Studies

Gas Lift Jumper Failure Investigation 1

Scope

Failure analysis was conducted to identify the root cause of a subsea gas lift jumper (GLJ) end termination leak. 

Services Provided

A structured methodology and procedure was developed to systematically identify the source and root cause of the leak. The work included internal and external visual inspection of the jumper utilising borescopes. Low pressure leak path testing. Disassembly of end termination fittings and a range of material characterisation, micro-analysis and mechanical  testing.

Benefits

The root cause of the leak was established and modifications to the design were actioned to mitigate any future failures.

Bulkhead Electrical Connector Investigation

Scope

An investigation was performed on a number of bulkhead electrical connectors recovered from subsea to check performance and for possible failure modes / locations.

Services Provided

A structured methodology and procedure was developed to investigate the connectors. Insulation resistance (IR) and continuity checks were initially performed followed by inspection and systematic disassembly of the connectors. Material samples were sent to the laboratory for further analysis.    

Benefits

Findings from the investigation identified key issues to manage and mitigate for future reliability improvements.

Gas Lift Jumper Failure Investigation 2

Scope

Failure analysis was conducted to identify the root cause of a subsea gas lift jumper (GLJ) end termination minor leak. 

Services Provided

A structured methodology and procedure was developed to systematically identify the source and root cause of the leak. The work included internal visual inspection of the jumper utilising borescopes. Low pressure and high pressure testing was performed on the jumper including all end fittings. Vacuum and positive pressure testing with helium was performed on the hose. The hose end fitting was dissected utilising ultra high water pressure cutting. 

Benefits

The root cause of the leak was established and enabled ongoing management of the issue.

FITA Electrical Connectors Investigation

Scope

An investigation was performed on a number of umbilical electrical cable connectors recovered from a subsea UTA to check performance and for possible failure modes / locations.

Services Provided

A structured methodology and procedure was developed to investigate the connectors. Insulation resistance (IR) and continuity checks were initially performed followed by inspection and systematic disassembly of the connectors. Material samples were sent to the laboratory for further analysis.  

Benefits

A number of failure locations and root causes were identified which provide insights into improving subsea electrical control system reliability.

Subsea Power and Comms Cable Failure

Scope

An investigation was conducted to identify the location, nature and root cause of a 48 V DC power and communications cable failure.

Services Provided

A plan was developed to initially identify the fault location via time-domain reflectometer (TDR). Once the location of the fault was identified a dive campaign was organised to investigate the nature of the fault at a midline connection. A partial disconnection due to an anchor drag and subsequent burnt-out pin was identified as the root cause. 

Benefits

Having identified the root cause of the failure a cable anchor drag mitigation plan was developed to prevent a re-occurrence of the issue.

Email
Phone
+61 (0) 432 765 009
Address
Suite 35
102 Railway St
West Perth
Western Australia
6005
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