P1987-3
Developments in IVIarine Teclinology, 4
Floating Structures
and
Offshore Operations
Proceedings of a Worl<shop on Floating Structures and Offshore Operations
Wageningen, The Netherlands, 1 9 - 2 0 November 1987
Edited by
G. van Oortmerssen
Maritime Research Institute Netherlands (MARIN), Wageningen, The Netherlands
ELSEVIER
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V
PREFACE
E a r l y 1986 t h e o f f s h o r e i n d u s t r y was a f f e c t e d by a d r a s t i c drop i n t h e p r i c e o f c r u d e o i l . As a r e s u l t , o i l companies d e f e r r e d new p r o j e c t s and r e c o n s i d e r e d t h e i r i n v e s t m e n t p o l i c i e s . A t t e n t i o n was f o c u s s e d on a r e d u c t i o n o f c o s t s o f b o t h new f i e l d developments and o p e r a t i o n s . T h i s has f o r i n s t a n c e l e d t o i n c r e a s e d i n t e r e s t i n f l o a t i n g p r o d u c t i o n systems o f v a r i o u s k i n d s , such as t e n s i o n l e g p l a t f o r m s , s e m i - s u b m e r s i b l e s , o r s h i p based systems. The t e c h n i c a l c h a l l e n g e s i n d e v e l o p i n g such systems f o r t h e h a r s h o f f s h o r e e n v i r o n m e n t a r e m a n i f o l d : m o t i o n b e h a v i o u r , r i s e r systems, mooring and dynamic p o s i t i o n i n g , t o name a few.
I t i s a g a i n s t t h i s background t h a t t h e M a r i t i m e Research I n s t i t u t e N e t h e r l a n d s (MARIN) i n Wageningen d e c i d e d t o o r g a n i z e an i n t e r n a t i o n a l Workshop on F l o a t i n g S t r u c t u r e s and O f f s h o r e O p e r a t i o n s , w i t h t h e aim t o p r o v i d e a p l a t f o r m f o r d e s i g n e r s , t e c h n i c a l managers and r e s e a r c h -e r s t o -exchang-e i n f o r m a t i o n and i d -e a s on -e x i s t i n g and n-ew f l o a t i n g -equipm-ent, o p -e r a t i o n s and d e s i g n t e c h n i q u e s .
The program o f t h e Workshop covers t h e f o l l o w i n g t h r e e main areas o f o f f s h o r e a c t i v i t i e s : • E x p l o r a t i o n , w i t h a t t e n t i o n f o c u s s e d on t h e b e h a v i o u r o f s e m i - s u b m e r s i b l e d r i l l i n g r i g s and
the t r a n s p o r t a t i o n o f such r i g s ;
• C o n s t r u c t i o n and O p e r a t i o n , w i t h c o n t r i b u t i o n s on o f f s h o r e c o n s t r u c t i o n a c t i v i t i e s , m a i n t e -nance and s u p p l y v e s s e l s ;
• F l o a t i n g P r o d u c t i o n / S t o r a g e / O f f l o a d i n g , w i t h papers on f l o a t i n g p r o d u c t i o n systems, m o o r i n g and dynamic p o s i t i o n i n g problems, s i n g l e p o i n t m o o r i n g systems and dynamics o f r i s e r s y s -tems.
C l e a r emphasis was p l a c e d on t h e l a s t t o p i c , s i n c e t h i s i s one o f t h e f a s t e s t e x p a n d i n g a r e a s of i n t e r e s t a t t h e p r e s e n t t i m e .
MARIN w i s h e s t o e x p r e s s i t s g r a t i t u d e t o a l l who have c o n t r i b u t e d t o t h e success o f t h i s Work-shop, e i t h e r as a u t h o r o f a paper, as s e s s i o n c h a i r m a n , as d i s c u s s e r o r as p a r t i c i p a n t .
Dr. Gerard v a n Oortmerssen Chairman, O r g a n i z i n g Committee
CONTENTS
S e s s i o n I : E x p l o r a t i o n
Dry T r a n s p o r t a t i o n o f Large Semi-Submersible U n i t s
F. van Hoorn ( W i j s m u l l e r T r a n s p o r t , The N e t h e r l a n d s ) and R.P. D a l l i n g a (MARIN, The N e t h e r l a n d s )
Do C a l c u l a t i o n s and Model T e s t s R e a l l y P r o v i d e I n s i g h t i n t o t h e Hydrodynamic Design A s p e c t s o f Semi-Submersibles?
J.A. van Santen ( M a r i n e S t r u c t u r e C o n s u l t a n t s , The N e t h e r l a n d s )
A C o n t r o l D e v i c e f o r S t a b i l i z i n g a Semi-Submersible P l a t f o r m w i t h a Large L i s t Angle i n Waves
a . T a k a k i , Y. H i g o , M. Kohno and P. X i u ( U n i v e r s i t y o f H i r o s h i m a , Japan)
S e s s i o n I I : C o n s t r u c t i o n and O p e r a t i o n
Keynote Address:
Computer S u p p o r t f r o m C o n c e p t u a l Design t o P l a t f o r m Removal J.E. Holmes (McDermott E n g i n e e r i n g London, U.K.)
D e t e r m i n a t i o n o f Hydrodynamic Loads f o r t h e S t r e n g t h - and F a t i g u e A n a l y s i s o f Semi-Submersible P l a t f o r m s
S.A.W. Janse (Gusto E n g i n e e r i n g , The N e t h e r l a n d s )
M o t i o n s and F o r c e s d u r i n g Heavy L i f t O p e r a t i o n s O f f s h o r e
H.J.J, van den Boom (MARIN, The N e t h e r l a n d s ) , A. Coppens (Heerema E n g i n e e r i n g S e r v i c e s , The N e t h e r l a n d s ) , R.P. D a l l i n g a (MARIN, The N e t h e r l a n d s ) and
J.G.L. P i j f e r s ( S h e l l , The N e t h e r l a n d s )
D e s i g n and C o n s t r u c t i o n o f a Semi-Submersible Workover V e s s e l "Amethyst" B. von U b i s c h ( U b i t e c , The N e t h e r l a n d s ) , F. D r e n t h ( W i j s m u l l e r E n g i n e e r i n g , The N e t h e r l a n d s ) and G. L o u w e r i e r ( S h i p y a r d "de Hoop", The N e t h e r l a n d s )
O p e r a t i o n a l Performance o f S u p p l y V e s s e l s
vm
S e s s i o n I I I : F l o a t i n g P r o d u c t i o n / S t o r a g e / O f f l o a d i n g
Keynote Address:
S t a t u s and Trends i n D e s i g n o f F l o a t i n g P r o d u c t i o n Systems H. Sannura and T. Naess ( A k e r E n g i n e e r i n g , Norway)
The E f f e c t o f Hawser E l a s t i c i t y on SPH M o o r i n g Loads
J.F. F l o r y ( T e n s i o n Technology I n t e r n a t i o n a l , U.S.A.), M.R. Parsey ( T e n s i o n Technology I n t e r n a t i o n a l , U.K.) and A.T. R a c t l i f f e ( U n i v e r s i t y o f N e w c a s t l e upon Tyne, U.K.)
T h e o r e t i c a l and E x p e r i m e n t a l I n v e s t i g a t i o n o f t h e Low Frequency M o t i o n s o f a S i n g l e Anchor Leg Moored Buoy and Tanker
W.J. B r e n d l i n g and D. W i l s o n ( B r i t i s h M a r i t i m e T e c h n o l o g y , U.K.)
The P r e d i c t i o n o f t h e B e h a v i o u r o f S i n g l e P o i n t Moored Tankers J.E.W. Wichers (MARIN, The N e t h e r l a n d s )
T u r r e t M o o r i n g s f o r Tanker Based FPSO's W.C. de Boom ( S i n g l e Buoy M o o r i n g s , Monaco)
F u r t h e r Developments on Permanent M o o r i n g Systems
R. U i t t e n b o g a a r d and F. Lange ( B l u e w a t e r E n g i n e e r i n g , The N e t h e r l a n d s )
Permanent S i n g l e P o i n t M o o r i n g s : D e s i g n Loads and R e l a t e d Problems A. P i t t a l u g a ( R e g i s t r o I t a l i a n o N a v a l e , I t a l y )
UKOLS - Ugland Kongsberg O f f s h o r e L o a d i n g System K.R. Mork ( U g l a n d E n g i n e e r i n g , Norway)
S i m u l a t i o n o f DP V e s s e l s by Model T e s t s o r C o m p u t a t i o n s
U. N i e n h u i s , H.J.M. de Bock (MARIN, The N e t h e r l a n d s ) and P.H. B r a k e r (Twente U n i v e r s i t y o f T e c h n o l o g y , The N e t h e r l a n d s )
Wave D r i f t Dam.ping C h a r a c t e r i s t i c s o f D i f f e r e n t O f f s h o r e S t r u c t u r e s G.E. Hearn and K.C. Tong ( U n i v e r s i t y o f N e w c a s t l e upon Tyne, U.K.)
On t h e D e t e r m i n a t i o n o f t h e S t a t i s t i c a l P r o p e r t i e s o f t h e B e h a v i o u r o f Moored Tankers
C o m p a r a t i v e E v a l u a t i o n o f N u m e r i c a l Methods f o r Non-Linear R i s e r Problems K. K o k k i n o w r a c h o s , K. Giese and P. M a r k o u l i d i s ( T e c h n i c a l U n i v e r s i t y Aachen,
F.R.G.) 233
P r o g r e s s i n t h e P r e d i c t i o n o f F o r c e s on C y l i n d e r s
J.J.W. van der Vegt and F. van Walree (MARIN, The N e t h e r l a n d s ) 251
D e t e r m i n a t i o n o f C r i t i c a l Wave Sequences f o r Moored F l o a t i n g S t r u c t u r e s
