FAILURE ANALYSIS OF WATER OUTLET PIPING IN THREE-PHASE SEPARATION UNIT

Abstract

This study was carried out to analyze complicated failure case within oil and gas field. Repetitive failures occurred in a line carrying water produced from a three-phase oil separator in the middle-stream oil process. The main objectives of the analysis are to define the failure mechanism, determine root cause and present practical recommendations. Failure analysis approach relied on macro examination, micro examination, mechanical testing and chemical analysis in addition to the available process information. Different models from literature were used within the study to compare them with the actual corrosion rate. The transformation of the flow type from single phase flow to multiphase slug flow caused removal of corrosion inhibitor film followed by mechanical deformation and micro corrosion pits formation.