Service Continuity

Decision support when inspection schedules are challenged
Keep your pipeline integrity on track

In-line inspections and excavations are critical components of every operator’s Integrity Management Program. Threat assessment plans can be disrupted for many reasons, including political instability, socio-economic pressures, operational factors and extreme weather events. In these difficult times, operators still bear responsibility for the safe and reliable operation of critical infrastructure to deliver vital resources. ROSEN delivers inspection services under challenging conditions worldwide and has the staff, training, equipment and procedures to ensure that inspections can be completed safely. However, in some circumstances, it may be necessary for an operator to either extend the schedule of a planned inspection or reaffirm the need to complete it in a required timeframe.

When operators are faced with having to reschedule inspection or remediation, our integrity experts are here to assist with Integrity Management Program decision support. We can support operators with a structured review of their assets’ integrity, based upon extensive experience, and recommend alternate schedules, supplemental activities and compliance requirements.

Our aim is to provide operators with decision support by providing the necessary experts for technical justification to:

• safely re-schedule,
• demonstrate what is critical and
• maintain compliance.

Level 1: Consultancy-led review

Through close dialogue with the operator, our integrity consultants will conduct an integrity review to assess whether it is possible to technically justify a delay of the current target inspection date and estimate the impact an ILI deferment would have on safe and reliable continued operation.

Using a qualitative risk-based approach drawing on industry codes, the review will establish whether there is sufficient evidence to justify:

• inspection deferment,
• whether additional assessment (or more data) is required to support a decision or
• whether deferment is not appropriate.

We will review prior threat assessments, inspection history, known integrity concerns and prescribed inspection intervals and will consider past, prevailing and future predicted operating conditions.

Deliverable and output

ROSEN will deliver a technical note that gives an independent expert opinion based on available data, whether or not ILI deferment can be technically justified and, if necessary, specify the Level 2 steps required to support this decision.

Level 2: Inspection window re-analysis

ROSEN will reassess the immediate and future pipeline integrity to provide the basis for a technical justification to update the existing inspection window:

• Established fitness-for-service (FFS) and corrosion growth assessment (CGA) methods will be used, in accordance with international codes and guidance.
• Threat evaluation and the effect of revised mitigation to push out intervention will be considered, with full consideration of past and future operational conditions.
• Where appropriate, ROSEN’s advanced corrosion growth assessment CGApro and AutoSCAN (ILI signal comparison) tools will be used to reduce prediction uncertainties and conservatism, thus extending the inspection interval.

Deliverable and output

ROSEN will deliver a detailed and optimized report that uses the Level 2 evaluation results to provide the next safe inspection date. To ensure ongoing operational integrity prior to the next inspection, the report will be supplemented by an anomaly repair plan and recommended key mitigation measures. If necessary, the Level 3 steps required to support this decision or to justify a further interval increase will be specified as well.

Level 3: Advanced critical inspection scheduling

We can complete a range of more detailed and advanced integrity assessments. These may be necessary where:

• the Level 2 assessment was not able to justify satisfactory deferment,
• it may be operationally difficult to complete a planned inspection that is intended to address significant existing integrity concerns or
• there is a requirement to inspect a critical pipeline asset.

The applicable assessment method(s) will be dictated by the individual situation and client preferences. They may include:

• detailed corrosion risk assessment, including flow and corrosion modelling and possibly direct assessment,
• fracture and fatigue assessment,
• FEA and advanced stress analysis,
• Virtual-Dig Up and
• probabilistic structural reliability assessments.

Deliverable and output

ROSEN will use the Level 3 evaluation results to provide the most accurate optimized safe next inspection date. Where appropriate, this will again be supplemented with a detailed anomaly repair plan and recommended key mitigation measures to ensure ongoing operational integrity prior to the next inspection.

Contact your local ROSEN representative to explore the options most suitable for you.