Fit-Up Solutions – Latest Practice
Denise Smiles
Summary
Good fit-up of pipes – what is it and why it is
necessary?
Defining terms – pipe end geometry
Methods for achieving better fit up
Application to SCR and fatigue senstive pipes
Application to flowlines
Conclusions
Pipe end geometry
Pipe End
Geometry
Example Calliper
Measurements
(no common datum)
2-D Geometry in
Laser
Measurement Data
Choice – Vernier Calliper
No Diameter
If you want this
1 193.4
2 193.9
3 194.1
4 193.8
Use this
Don’t expect to know the pipe shape!
Choice – Laser Tool
If you want to fit pipes together
Use this
Pipe shape is known
Platform Geometry
Riser facts
Risers are:
Dynamic structures and hence fatigue sensitive
One of the most challenging aspects of deepwater development
Failure would cause pollution problems
Issues the riser has to deal with:
Waves
Currents more than 1 knot
Winds Hurricane Katrina decreased the expected life of risers that were
affected
Critical regions:
Flexjoint attachment to floating vessel
Touchdown region as riser connects with sea bed
Automatic Welding
Automatic
Welding is used
routinely
Better control over
parameters
improves welding
reliablity
HiLo is one of the
key factors
Cut-outs are a
significant expense
Internal Pipe Joint Mismatch (HiLo)
Internal HiLo mismatch
must be less than 0.5
mm
4
End Matching – pick pipe and
rotate to fit
Rotate to fit
Definition of the
Rotation Mark location
with respect to the
Free Pipe (right)
If pipes are not
rotated exactly
right
HiLo increases
dramatically
HiLo
Sweet
spot
Rotation
Rotation
Examples of pipe fit up software
Bad fit up, shapes do
not match
Good fit up, shapes
match
Graphical Explanation of
reordering requirements
Pipes Requiring
Reordering (%)
100
80
60
40
20
0
1.5
1
0.7
HiLo Requirement (mm)
0.5
OMS Software “Best Possible” Fit
OMS Fit Up Software provides users with a “best
possible” fit up based on a perfect rotation and
alignment of a pipe
Perfect alignment and perfect rotation will not
be achieved all of the time
The next slide shows how alignment and
rotation will affect the HiLo achieved
Flowline Solutions
OMS has created solutions for Flowlines
HiLo tolerances are relaxed compared to SCR’s
Fabrications efficiencies can be highly cost
effective
Solutions are designed to be as easy to
implement as possible
Results are faster and cheaper production
What to expect
A typical flowline project will have fit up
requirements of:
Internal HiLo = 1 mm
External HiLo = 2 mm
Such a HiLo requirement would be expected to
result in fit up problems in around 5 – 10% of
the pipes
Any problem pipes would be recycled back into
the firing line sequence at any time
Obtaining a better fit-up
If the HiLo requirement are lowered – i.e. for a
more accurate fit up then some changes to the
fit up procedure will have to be made
Achieving a lower HiLo becomes harder the
lower the HiLo requirement
Even small HiLo reductions can result in many
more pipes that need reordering
Larger reductions will result in all pipes needing
to be reordered
Firing Line
Welding Stations and AUT etc
Ready rack
Beveling
shed
Unloading rack
Loader - full
Loader - empty
Pipe Yard
Pipe stacks contain measured
pipes awaiting welding
Sorting rack / buffer area
Software
used here
Implementation
Sorting rack or ‘buffer area’ in
the pipe yard
Software used when pipes are
pulled from stack
Pipes are rolled out on the
sorting rack and checked
All pipes delivered to firing
line can be used
in sequence
Summary
Management of fit up can be achieved for any
HiLo ID (0.5 mm to 1.0 mm) or OD (1-3 mm)
Problem fit-ups that would normally slow
production can be managed so that they rarely
occur
Cost savings generally pay for the solution
OMS have a range of solutions that enable any
firing line fit up scenario to be improved
Case Study No 1. 20” UOE SCR for Gulf of
Mexico, SLAY – Shell Amberjack/Allseas
Critical pipe lay for project
0.5 mm HiLo requirements
UOE pipe with significant peaking, shape and
size variations
Failed attempt by calliper measurements
Requirement to develop solution with Shell
1 SCR, 1 Spare SCR and contingency planning
Measurement of pipes
Pipes measured
in New Iberia
Marks on pipe
from failed
attempt to
measure using
calipers
UOE Shape problems
UOE pipes often have
peaking problems near
long seam
This makes it difficult
for these pipes to be
fitted together
Methodology
Arrange pipes in sequence provided by OMS
Mark one end of each pipe with the rotation
datum mark
When welding pipes rotate new pipe to align
datum with long seam of the existing pipe
Spacer to align
Check HiLo is within specification and weld
Small 20 mm sections allowed to have 0.7 mm
HiLo
Marking datum and rotating to fit
System proven during pipe lay
Pipes were welded into double joints then put
into Main Line for SLaying
All HiLo’s were found to be in specified
tolerance of 0.5 mm for fatigue critical sections
and 0.7 mm for small regions around the girth of
the pipe
Inspector observed that fit-ups were so good
that the pipes were brought together and
needed no adjustment before welding
Conclusion – Case
study 1
Difficult SCR was built to specification
All pipes welded in sequence without
requirement for any contingency pipe to be
used
All fit ups within the HiLo requirement
Project manager stated that he would repeat
the methodology the next time
Case Study No 2. 8” and 10”
Seamless Pipe for spoolbase welding
1 x 8” SCR
1 x 10” SCR
Cold end sized pipes
No counterboring
HiLo to be achieved by:
Specific architecture (matching ends)
Rotation of pipes (to best fit angle)
Specific Pipe Ordering
Pipes are put
together in a specific
order to create the
SCR architecture
A significant
improvement in Fit
Up is achieved by
this specific odering
of the pipes
Client reported
excellent fit up of
pipes for this project
Fit up table provided to client
Joint Number
Weld Number
Pipe Fixed
(mm)
Pipe Free (mm)
ID Max Hi/Lo
(mm)
SCR ID Min
Hi/Lo (mm)
ID Rotation
(mm)
OD Max Hi/Lo
(mm)
OD Min Hi/Lo
(mm)
Negative
Rotation
Tolerance (mm)
Positive
Rotation
Tolerance (mm)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
ATP-GR3.01
ATP-GR3.02
ATP-GR3.03
ATP-GR3.04
ATP-GR3.05
ATP-GR3.06
ATP-GR3.07
ATP-GR3.08
ATP-GR3.09
ATP-GR3.10
ATP-GR3.11
ATP-GR3.12
ATP-GR3.13
ATP-GR3.14
ATP-GR3.15
03025_A
03023_B
01022_A
01005_B
01148_A
01064_B
01204_B
01207_B
01239_A
01303_A
01224_B
01234_B
01231_A
01320_A
01449_B
03023_A
01022_B
01005_A
01148_B
01064_A
01204_A
01207_A
01239_B
01303_B
01224_A
01234_A
01231_B
01320_B
01449_A
01297_A
0.76
0.37
0.57
0.61
0.89
0.78
0.68
0.75
0.98
0.82
0.93
0.87
0.99
0.75
0.89
0.21
0.37
0.15
0.13
0.15
0.14
0.17
0.18
0.18
0.16
0.16
0.20
0.16
0.16
0.13
106
118
-267
172
-87
-154
-236
158
-249
314
-186
172
156
192
-7
0.93
0.86
0.61
0.64
0.74
0.53
0.71
0.76
0.84
1.05
0.64
0.85
0.67
0.73
0.53
0.39
0.53
0.37
0.38
0.18
0.36
0.30
0.40
0.46
0.44
0.22
0.43
0.26
0.38
0.30
-26
N/A
-37
-30
-23
-24
-13
-21
-26
-15
-13
-10
-14
-20
-10
33
N/A
29
36
16
16
10
15
17
9
10
13
9
14
14
Conclusions – Case Study 2
Efficient measurement of pipes
Cold end sized pipes give good fit up but not
good enough for SCR
Rotation gave better fit but still not good
enough
Unique string build gave best result
SCR build successfully and efficiently
Case Study No 3. Seamless pipe in Brasil,
Spoolbase BC10/TU/P56 – Petrobras/Subsea7
Requirement for ID HiLo of 1.0 mm and OD HiLo
of 2.0 mm
Pipes measured offline
Pipes loaded onto sorting rack
Sequencing of pipes in software
Pipes put into ready rack for firing line in
sequence and with rotation datums marked
Measurement
Pipes are delivered to racks for OMS to measure
Operating the system on the
spoolbase
Pipe sorting
Sequenced pipes
OMS Tried and Tested Solution
Rotation of pipes to find the best ID and OD fit provides a huge
benefit in the firing line
The majority of pipes can be used directly
Problem pipes are identified before fit-up at the welding station
A method of dealing with problem fit ups can be implemented in
various locations (examples are provided below)
The impact on logistics/pipe handling is minimal
Benefits are very significant, due to avoidance of fit-up issues
and avoiding disruption due to removal of bad pipes at a welding
station or underaking remedial work in the firing line
Conclusions – Case study 3
Most pipes can be welded directly (using rotation)
A small proportion need to be held back or diverted
There are several schemes to achieve this
OMS will endeavour to find the optimal solution for
client in terms of:
Minimised Logistics
Ease of implementation in a given yard/spoolbase scenario
Lowest cost/effort in fabricating the strings/stalks overall
Overall Conclusions
Deliver solutions that achieve the best possible fit-up of
pipes for client – flowline or SCR
Philosophy:
Measure + Analysis or Visualisation Software = Best
Fit-up via End Matching or Counterboring
Solution can be tailored to meet client needs
Best fit-up solution using true pipe geometry
Minimise overall logistics to achieve best result
Up-front management of problems
Packages includes operators or operator training