Shallow water flow hazard: a challenge in deepwater drilling
深水钻探面临的挑战:浅水流灾害问题

One of challenges in deepwater drilling is shallow water flow(SWF)hazard,which is referred to that sand and water eject into drill hole shrewdly,when drilling into poorly consolidated overpressured layer,and cause damage to drill platform.SWF hazards are only met in deep water regions and occurred in hundreds meters below sea floor.They locate in the sloppy loosen sands with overpressure,covered with shale with low permeability.The origin of overpressure is often related to rapid deposit compression,or to geological structure and gas hydrate.SWF sands have the properties of low density,low velocity and high Vp/Vs,and hence can be identified by the seismic exploration techniques.Deepwater drilling will be proceeded in our country,and the studies of SWF hazards should be carried out in order to avoid and lessen the potent hazards in the deepwater drilling works.