KhPD has a vast flowlines networkof more than 3,333 km total length, these flowlines shall be inspected one timeevery five years. Maintaining the integrity and production rate of theseflowlines is obligatory while there is a limitation in resources to inspect thehuge numbers of flowlines in order to prevent leaks occurrence. The optimumsolution is to establish a risk based semi-quantitative methodology forassessing the corrosion likelihood and consequence of existing flowlines. Thiswill allow KhPD to focus on highest risk flowlines, prioritize flowlines withhighest corrosion risk in terms of inspection, prioritize flowlines withhighest corrosion risk in terms of rehabilitation and replacement and prioritizationof maintenance plans.
This study was conducted by creatinga decision matrix support system enables us to evaluate various aspects of ourflowlines and rank them according to a risk severity. With the lack of RiskBased Inspection Methodology or software in the industry for off plot piping, thisstudy has adopted the concept of API-580 by conducting a risk assessment modelbased on two criteria: corrosion likelihood and consequence of corrosion.
Under each criterion, there areitems attributes in the final scoring of the criteria. Both criteria forcorrosion likelihood and consequence of corrosion are developed with theconsideration of some possible factors that affect the flowlines integrity orsafety.
This matrix engineering analysisstarts with gathering detailed data for Khurais’ fieldscrude lines. Approximately 200,000 data inputs covering each flowline (atotal of 310) have been placed into the matrix. The flowlines are then rankedbased on their score from the likelihood and consequence of corrosion. Thisallows for prioritization of flowlines based on their relative risks againstleaks by proactively inspecting and repairing flowlines. The assessment rankingresults were used to appropriately identify the required action to reduceoverall operational risk and to streamline the inspection activities.