)
)
The ability to be manufactured and spooled in long
lengths.
Liner qualification and development
process
The qualification of the liner has been generally
undertaken in accordance with the API Recommended
Practice 15S (First Edition March 2006) “Qualification
of Spoolable Reinforced Plastic Line Pipe”, with further
reference to the applicable ASTM test standards, API 17
series and NACE standards. The testing and qualification
procedures have been undertaken in a number of locations
including Germany, Norway and the UAE.
The final IFL liner matrix is comprised of a solvay
Solexis PVDF inner liner, a tightly woven aramid core, using
Dupont Kevlar fabric and this is completed by an our layer
of abrasive resistant Thermoplastic Polyurethane from
BASF. Other versions of the liner are also available for less
aggressive service conditions, such as water reinjection
and gas transmission.
All the principal objectives and milestones of the
project have since been totally fulfilled. A new enhanced
version of the IFL liner has been developed. Performance
testing has been undertaken which has been able to
completely justify the utilisation of IFL in very aggressive,
hot, sour hydrocarbon service conditions of up to 110˚C,
with IFL liners exhibiting a stand-alone burst capability of
up to 110 Bar.
Prototype testing
The concept of prototype testing was developed at
the start of the R&D project. It was felt essential that
the theoretical IFL liner towing load formulations and
predictive software that were derived from the finite
element analysis were checked and if necessary calibrated
against empirical results. This enables future confidence in
accurate assessment.
This concept was further developed to include the
opportunity of full liner insertion rehearsals and onsite
training of the actual installation crews that would be
ultimately working with the product offshore. For ease
of access for the main construction and installation task
force, the prototype test-yard was established close to the
main APS operations centre in Dubai.
Much of the equipment used during this phase of the
project was also developed for offshore installation, thus
providing an ideal opportunity to put workers and tools
together during the insertion and rehearsal process.
The prototype set-up comprised of two steel platforms
constructed about 350 m apart, each with risers and 5D
bends, between which a wide variety and combination
of 8 in. dia. straight spools and bends were assembled,
disassembled and swapped around so as to produce the
60 differing candidate insertion configurations that were
undertaken during the four months of testing.
During the final stages of this project, liners were
actually inflated and hydro-tested as would be the case in
the actual offshore candidates.
IFL installation; summer 2013
In the summer of 2013, the final phase of the IFL
development project was set in motion when APS installed
IFL in a 8 in. OD crude oil pipeline in Petronas’s Samarang
oilfield, offshore Sabah, East Malaysia in the South China
Sea, about 72 km northwest of the Labuan gas terminal.
The line was operating at 10 bar. The pipeline, slightly
shorter than 2 km, was nearing the end of its natural
service life, after operating for more than 35 years.
Samarang was initially developed by Sabah Shell in
1975, with PCSB becoming operator in 1995, turning it into
a hub for production of adjacent fields.
A thorough inspection of the existing subsea
pipeline preceded detailed planning of the Samarang IFL
rehabilitation project. This process included collation
of all data relative to prevailing operating
parameters and conditions. Inspections were
carried out by intelligent pigs and other
external remote inspection tools.
This data helped engineers assess the
general condition and remaining wall thickness
of the existing pipeline and verify the IFL
liner size requirements in the event that an
enhanced tight-fit high pressure liner was
required. Decommissioning, cleaning and
gauging preceded offshore deployment of the
IFL-marine spread, as did shipment of the liner
drums to a local supply base, where the liners
were further processed into a folded format for
shipment to Samarang field.
The actual IFL liner installation process
was extremely fast, being operated at speeds
of approximately 10 m/min., hence providing
for the insertion of a typical 2 km liner in a
period of no more than 3.5 hours. The IFL liner
Figure 5.
Liner guidance into riser.
62
World Pipelines
/
JUNE 2015
