Integrity of Non-Piggable Oil and Gas Flowlines Contributing Factors and Proposed Mitigation Methods

Abstract

Abstract Integrity management of Non-Piggable Gas and Oil Flowlines is a challenge. In this paper, Contributing Factors affecting Flowlines integrity and life cycle cost effective Mitigation Methods are discussed. Gas Flowlines were designed without pigging facilities and handle wet natural gas. Several leaks were reported due to internal and external corrosion. Hence, it was essential to assure integrity of those lines. One Flowline was piloted for conventional MFL intelligent pigging driven by nitrogen. Portable launcher and receiver facilities were installed avoiding elbows which exist only at both ends of the Flowline. Intelligent pigging revealed few integrity threats anomalies along the trial Flowline, replacement of defective sections were completed. The project completed successfully for implementing pigging of non-Piggable gas Flowlines for condition assessment and proactive repairs actions, which increase confidence in plant condition and assure health and safety. Number of leaks in oil Flowlines is increasing in recent years mainly due to internal corrosion, Several corrosion mitigation options are considered in this paper including Solar Chemical injection, HDPE internal lining, Non-metallic line (RTP) oil Flowlines. HDPE internal lining is proposed for corrosion mitigation of oil Flowlines with welded coupling and one-way valve in the liner