SIMULATION OF SCOUR PREVENTION METHODS FOR OFFSHORE PLATFORM IN CHENGDAO OIL FIELD

摘要

This paper presents a numerical study of the scour preventions around a circular pile in the ChengDao Oil Field conditions. The turbulence of threedimensional flow is obtained by use of the Large Eddy Simulation (LES) model. Scour always makes pile foundation exposed, the platform deck oblique, and affects both lateral and axial pile performance and capacity, so the problems of aging platforms are more serious. The paper describes two methods of scour prevention proposed by the author. The self bury method is putting burbling facilities around the leg near the seabed, and fluid diversion method is setting flow deflectors on the leg. The CFD results suggest that the height of burbling facility and the flow deflector position of fluid diversion strongly influenced the flow velocity near the pile, which is the main factor of silt transportation. When the height of burbling facility increase, flow velocity near the seabed around leg decrease, and moved silt deposit; when the flow deflector position of fluid diversion decrease, the flow deflected by flow deflector increase. Results obtained from the computer model have demonstrated the CFD method is suitable for modeling the effect of factors about the scour prevention, and method of self bury is better than fluid diversion.