Dynamic boundary of floating platform and its influence on the deepwater testing tube

The motion of the floating platform is one of the important factors influencing the safety of testing string. The allowable motion limits of various floating drilling platforms are discussed and their calculation formulas are presented, based on which the nonlinear dynamic response characteristics of the testing tube are investigated through ABAQUS software. Results show that an excessive offset of floating platform will cause many problems to testing tube, such as operation difficulty in rising and landing pipe string, disconnection difficulty of testing tree in case of emergency. Under heave motion and slow drift motion condition, the maximum Mises stress appears in the part closed to the upper end. The heave and horizontal motions of the platform have a superposition influence on the axial force of the pipe. So, a more precise dynamic theoretical model should be developed to study the longitudinal-transverse coupled vibration of testing string in the future.