IPLOCA Excellence in Project Execution Award€¦ · IPLOCA Excellence in Project Execution Award...
Transcript of IPLOCA Excellence in Project Execution Award€¦ · IPLOCA Excellence in Project Execution Award...
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18-05-2016
EFU
ITO / KFM
Van Oord Offshore bv submission
IPLOCA Excellence in Project Execution Award
Tetney sealine replacement project
Van Oord Offshore bv
Project: Van Oord Offshore bv Submission IPLOCA Excellence in Project Execution Award
Client: International Pipe Line & Offshore Contractors Association
Van Oord Offshore bv
2 of 8 18 May 2016
Contents
Contents ........................................................................................................................................... 2
1. Business Profile ................................................................................................................. 3
2. Project description .......................................................................................................... 3
2.1 Project introduction ......................................................................................................... 3
2.2 Project constraints (findings) .......................................................................................... 5
3. Project execution method (solutions) .................................................................. 6
4. Project achievements ..................................................................................................... 8
Project: Van Oord Offshore bv Submission IPLOCA Excellence in Project Execution Award
Client: International Pipe Line & Offshore Contractors Association
Van Oord Offshore bv
3 of 8 18 May 2016
1. Business Profile
For the last decades, Van Oord Offshore has delivered on numerous worldwide projects of-
fering a variety of highly specialised offshore installation and construction projects. We have
developed and expanded our capabilities in the offshore market, evolving into a world-
renowned engineering, procurement and construction (EPC) contractor. Our fully integrated
EPC services encompass detailed design and verification, procurement of materials and as-
sociated services, and of course installation and commissioning services; all delivered in one
complete package.
The extensive range of offshore services we offer includes:
- Subsea Rock Installation
- Pipeline shore approaches
- Shallow water pipeline installation
- Offshore dredging, trenching and backfilling
- SPM (Single Point Mooring) installation
- GBS (Gravity Based Structure) installation
2. Project description
2.1 Project introduction
The Humber Refinery is owned by Phillips 66 Ltd and is located in South Killingholme, North
Lincolnshire, England. The refinery receives crude supply through a single 36 inch NB pipe-
line that runs from a Catenary Anchor Leg Mooring (CALM) buoy, located in the Humber es-
tuary, to a crude oil transfer terminal at Tetney, Lincolnshire, England. The 36inch NB crude
oil import pipeline, commissioned in 1971, has an approximate total length of 8.4km and
runs from Tetney Oil Terminal under flat agricultural land, over one river, under environ-
mentally sensitive salt marshes and sands and then beneath the seabed to a pipeline end
manifold (PLEM) located on the seabed.
Project: Van Oord Offshore bv Submission IPLOCA Excellence in Project Execution Award
Client: International Pipe Line & Offshore Contractors Association
Van Oord Offshore bv
4 of 8 18 May 2016
The PLEM is positioned approximately 4km from the shoreline and is connected to the tank-
er off-loading CALM buoy by a single string of 20inch NB sub-sea hoses. The buoy provides
an offloading point for tankers carrying crude oil for the Company’s Humber Refinery and
Tetney provides an intermediate store for the crude until it is pumped to the Refinery for
processing.
The monobuoy is anchored in a water depth of approximately 16 metres below chart datum.
The Humber estuary is tidal and currents can reach nearly 3.6 knots. Visibility underwater is
poor due to the amount of naturally occurring silt suspension in the water.
Inspection results gathered over a period of approximately twelve years have identified that
localised wall loss due to corrosion will result in maintenance work being necessary at four
points by 2015. In view of the age of the line and the fact that there are already four clamps
installed on the subsea section, Company has hired Van Oord Offshore to replace the sub-
sea pipeline end manifold (PLEM) and part of the transfer line.
The Tie in between the existing pipeline and the new pipeline will be at the beach around
Mean High Water at Kp 0.
The Humber Refinery is owned by Phillips 66 Ltd and is located in South Killingholme, North
Lincolnshire, England.
Project: Van Oord Offshore bv Submission IPLOCA Excellence in Project Execution Award
Client: International Pipe Line & Offshore Contractors Association
Van Oord Offshore bv
5 of 8 18 May 2016
2.2 Project constraints (findings)
In order to execute this project Van Oord Offshore had to overcome the following main chal-
lenging project constraints:
Environmental
The access to the working area was
restricted to offshore. All equipment
and personal had to be mobilised over
water.
During water levels higher than mean
high water the complete beach was
submerged,
7m tidal difference and high currents
Preparation and execution
Short preperation time
Beach only accesible after 1st
of march
2015
Existing pipe should be fully operational until 8th
of may 2015
New pipe should be fully operational from 12th
of july 2015
Only 65 days for the pipe to be out of operation, which coinsides with the major
maintenance shut down window of the refinery
Delay of first oil was very costly for the client therefore the project execution method
shoud be risk “free”
Scope of work Van Oord
• Removal and reconnection of the single point mooring (SPM) and subsea hoses.
• Excavation and backfilling of the trench for the new pipeline.
• Fabrication, installation and piling of a new PLEM.
• Pipe fabrication, welding and NDT.
• Field joints, in- and external corrosion coatings and concrete weight coating.
• Installation and pre-commissioning of the replacement pipeline.
• Removal of a section of the existing pipeline between kp 0 and kp 0.38.
• Removal of the existing PLEM, PLEM frame and pipeline S-bend.
• Capping the open ends of the existing pipeline.
Restricted area at Tetney beach
Project: Van Oord Offshore bv Submission IPLOCA Excellence in Project Execution Award
Client: International Pipe Line & Offshore Contractors Association
Van Oord Offshore bv
6 of 8 18 May 2016
3. Project execution method (solutions)
In order to overcome the project constraints Van Oord Offshore had to come with an innova-
tive project execution method as conventional execution methods were not suitable or too
risky;
A string yard on land in combination with an offshore pull was not possible due to
the land access constraint
A float and sink method would have been possible, but was considered to be too
risky due to the high currents perpendicular to the pipe trajectory
A pipe lay barge solution would have been possible but due to the shallow area this
would have involved large quantities to be dredged (not favourable for
environmental and morphological reasons)
Execution method
43 pipe strings with a length of 100m (8 pipe joints) were fabricated in a yard in
Amsterdam and loaded on the
specially designed String
Barge
The specially designed string barge and a specially designed accomodation barge
(120p) were beached and ballasted during spring tide at the beach near Tetney, for a
duration of approximatly 1.5 month.
Loading String Barge
Accommodation barge and String barge
at the beach
Project: Van Oord Offshore bv Submission IPLOCA Excellence in Project Execution Award
Client: International Pipe Line & Offshore Contractors Association
Van Oord Offshore bv
7 of 8 18 May 2016
The stringbarge with a dimension of 120m x 36m consisted out of the following
main items:
o 4 specially designed and build gantry cranes to move the pipestrings into
the firing line
o A pipe string stack, consisting of 43 pipe strings of 100m long stacked 4
high
o A firing line
consisting out of
adjustable rollers
to allign the strings
o Two welding and
coating locations
to connect the
strings to
eachother
Two adjustable
launchways (one to
onshore and one to
offshore) were built at the
beach to guide the pipe
from the barge to the
beach.
Thirtyeight 100m pipestrings and the PLEM were pulled offshore through a pre
dredged trench (with a curve with a radius of 10000m) to the final position using
a 600mTon winch installed
on a pull barge. After each
pull of 100m the next
section of 100m was
welded to the allready
pulled pipe.
String barge
Launchway
Pull barge
Project: Van Oord Offshore bv Submission IPLOCA Excellence in Project Execution Award
Client: International Pipe Line & Offshore Contractors Association
Van Oord Offshore bv
8 of 8 18 May 2016
Five 100m pipestrings were pulled over rollers towards the shore using terrestrial
equipment.
After the final pull and removal of the stringbarge the onshore section and
offshore section were connected at the beach. After the connection the section at
the beach was post
trenched.
After post trenching the new pipe was connected to the existing pipe using a
spool piece.
4. Project achievements
The innovative project execution method proofed to be a great success. The project was de-
livered in time and within budget.
The method was a robust solution in order to mitigate the project constraints. The biggest
project constraint that the working area was fully submerged during high water was used as
an advantage: during high water spring the barges with the pipe were beached, during low
water dry equipment was used to install the launch ways and to post lower the pipe at the
beach.
Using barges and not a large temporary man-made island at the beach, reduced the morpho-
logical and environmental impact at the beach significantly.
Post trenching