Nonlinear Dynamic Characteristic Analysis of a Landing String in Deepwater Riserless Drilling

Table 1

Parameters of the standpipe.

Parameter	Case 1	Case 2
Outer diameter	100 mm	100 mm
Inner diameter	50 mm	50 mm
Elastic modulus	206,000 MPa	206,000 MPa
Density	7846 × 10^−9 kg/mm^3	7846 × 10^−9 kg/mm^3
Pipe length,	10 m	200 m
Upper boundary condition,	0.005 sin (10t) m	0.01 sin (4t) m
Horizontal load in the middle of the pipe,	2000 sin (10t) N	200 sin (4t) N