A Novel Installation Methodology for Ultra-Large Diameter Sea Water Intake Pipelines

摘要

A seawater intake system with four 1500 m ultra-large diameter steelpipelines (2700 mm dia.) had been designed and fabricated to supply200000 cubic meters per hour seawater into a 360,000 BPSDcondensate refinery in Bandar Abbas/IRAN. The usual float and freeflood had been considered for installation of the pipelines in basicengineering phase. Within the detailed installation engineering theproposed method was found to be not applicable leading to line failurewithin submergence operation. Other potential installationmethodologies were studied and found uneconomical imposing veryhigh rate of cost and time impacts to the project. A novel installationmethodology using partial compartments from the pipeline body itselfthroughout a time-based sequential ballasting procedure was proposedand successfully undertaken based on the series of sophisticated finiteelement analyses and engineering design challenges. The paperdiscusses the core analysis, engineering design and operationalchallenges in detail and reviews the undertaken solutions to resolvevarious problems encountered throughout the project and try to sharethe lessons learned.