Qualitative Root Cause Assessment Approach to Quantify the Impact of Flowline Internal Coating Disbondment

Abstract

Abstract Objective and Scope (25-74 words) During High Speed Flushing (HSF) of two water injection flowlines (WIFL) located at offshore Sabah, Malaysia at water speed of 3.0m/s, internal Fusion Bonded Epoxy (FBE) coating flakes were observed being ejected from end of flowline by ROV. There were concerns that the dis-bonded FBE flakes would block the wells during operation causing a reduction in the water injection performance. The objective of this qualitative root cause analysis is to determine the likelihood of further internal FBE coating disbondment during operation and assess whether the water injection flowlines internal FBE coating failure is localize or systemic. Systemic failure is defined as the location of the internal FBE coating disbondment has no specific pattern and is randomly distributed throughout the entire flowlines. Localize failure is defined as the failure pattern is discernible and limited to a few specific linepipe along the flowlines. Methods and procedures, process (75-100 words) The qualitative roots cause assessment of the internal FBE coating disbondment consists of the following work streams: Results, observations, conclusions (100-200 words) In conclusion, there is no evidence to suggest that the FBE disbondment in the water injection flowlines was a systemic failure or that further application of flow would cause more coating to detach from the flowlines. It is deemed that the internal FBE disbondment is high likely localized based on the following observations: New/novel information (25-75 words) The water injection flowlines had started its operation since September 2015 and the wells performance is closely monitored by WRFM team. To date there is no decline in water injectivity being observed or reported for all water injection wells. Hence, the qualitative root cause analysis approach employed by the project team is deemed a workable analysis method in concluding the water injection flowlines internal FBE coating failure is localize and low likelihood of further disbondment during operation.