Introducción
a la ingeniería offshore – Subsea Infrastructure
Sergio Antonio Muñoz Pinzón
November, 2015
1. The drillship Transocean Deepwater
Discovery has a drilling riser with the following properties:
Length: 2000 m
External diameter: 21,25”
Wall width: 0,812”
Young’s modulus: 2,07e+11
Pa
Axial force: 9e+6 N
Assuming
the whole riser is immersed in fresh water in a water depth of 2000. A constant current (same direction and
velocity) of 2 knots is loading the whole riser. It is necessary to take in account
the axial force. However, the effects of
gravity, internal and external hydrostatic pressure can be neglected.
Plot
the graphs of (i) deflection, (ii)
angle of rotation, (iii) shear force and (iv) bending moment along the whole drilling
riser for the following cases:
a.
Riser
with both ends fixed
b.
Riser
with both ends equipped with ball joints
For
both cases a. and b. the riser can be assumed to be a tensioned beam,