Development of simplified deep sea water intake system - Plan, design, analysis and experiment

Abstract

A simplified intake system for pumping deep sea water (DSW) far away from land is developed. Based on a development system for natural gases or oils, the structure in new concept for DSW intake consists of a riser pipe, an anchor, and a buoy. The riser connected with a polyethylene pipe stands vertically in the low tension due to the specific gravity of 0.95 of a Polyethylene without a mooring line. The bottom end of the riser is positioned far from the seabed in order to prevent the influx of particles on the seabed. With a hose inserted on hole of the riser pipe and a water pump on a ship the DSW located at deeper than a water depth of 200m is transferred to a tank on a ship. The structural safety of the riser pipe made from a P.E. material that has a low allowable strength must be checked with the numerical or experimental studies before it is actually installed at sea. From the results of the 3-D dynamic structural analysis it is concluded that the designed riser pipe under a severe ocean environment can perform its function without destruction. The actually experiment at sea was carried out to certify the pumping performance of the newly designed development system. From the results of the experiment, it is demonstrated that the DSW intake can be done with the development system suggested in this study in very simple and low cost. Copyright ？ 2008 by The International Society of Offshore and Polar Engineers (ISOPE).