Numerical and experimental investigation for extreme storm-safe drilling riser

Abstract

ABSTRACT Extreme storm-safe drilling riser, a solution to overcome high time cost of riser emergency retrieval under the situation of the imminent typhoon arrival, is to modify the existing drilling riser to make it disconnectable and leave the long riser string below in a freestanding mode to survive. The buoyancy can maintains neutral during the normal drilling operation. However, locally the buoyancy can will have some effect on the riser system nearby. Numerical analysis and a hybrid scaled truncated model test in the water tank are conducted for the two critical configuration modes: connected mode and freestanding mode. A series of load cases under various current and wave, buoyancy upthrust are conducted in the experimental test to evaluate the hydrodynamic and strength performance of the riser near buoyancy can. The numerical analysis, experimental model design, data post-process method and result discussion can be a valuable reference for deepwater drilling engineering.