RESULTS FROM A PREDICTIVE FLOW MODEL USED TO ASSESS INTERNAL CORROSION LIKELIHOOD AND THE SUBSEQUENT DEVELOPMENT OF A RISK-BASED INTEGRITY PLAN FOR A NATURAL GAS GATHERING SYSTEM

摘要

A predictive flow model was used to identify specific locations where internal corrosion is likelyrnto occur in an aging gas gathering system. The model integrates the effects of a fully compositional,rnmechanistic pipeline simulation model combined with digital elevation profile data to determine specificrnlocations and severity of identified stagnant water hold-up locations. The work was completed for 17rnhigh-pressure line segments (230 cumulative kilometres) and 96 low-pressure collection laterals (650rncumulative kilometres) covering a region of approximately 14,500 square kilometres. Conventionalrncorrosion rate models suggest a very low unmitigated corrosion rate of 0.15 mm/year (6.0 MPY),rnhowever, an overall integrity assessment was warranted given that the majority of the gathering systemrnhas been operating for approximately 40 years without an internal corrosion mitigation program inrnplace. The results of the evaluation were used to develop a focused inspection and corrosion mitigationrnplan for the most highly susceptible pipeline segments identified within the study.