A risk-based inspection (RBI) programme, covering ZADCO's offshore production and onshore processing facilities, has recently been completed. The scope of work, which included over 25,000 items of static pressure equipment, piping, relief valves and pipelines, had key objectives of reducing the risks to personnel, the environment and to the business through compliance with a regional, corporate Code of Practice for the identification and integrity assurance of health, safety and environmental critical equipment and systems (HSECES).
The RBI programme for static equipment and piping, which comprised over 80% of the total equipment count, was carried out in two phases: Phase 1, a screening phase, comprised qualitative risk assessments at the system level; system risk was based on the worst-case combination of failure likelihood and loss of containment consequence applicable to that system. Equipment and piping within low risk systems were allocated generic inspection plans, consistent with equipment type and materials of construction. Phase 2 comprised semi-quantitative risk assessments of the remaining equipment and piping within medium and high risk systems. All credible degradation mechanisms were separately risk ranked and inspection plans were allocated, based on relevant degradation mechanisms, equipment type, accessibility, materials of construction, internal lining/cladding and insulation status. Both phases of the RBI implementation were backed-up by a series of multi-disciplinary workshops during which the initial assessments were subject to rigorous challenge and review.
This approach has enabled ZADCO to fully implement RBI in a timely and efficient manner, with the screening phase, in particular, facilitating appropriate focus on current and emerging integrity threats to the facilities. A key element of the programme was the development of an RBI methodology and configuration of software to integrate much of ZADCO's existing integrity management practices with an innovative, efficient approach to risk assessments and inspection planning.