Chemical Technology June 2015

19 / 40

17
Chemical Technology • June 2015
Construction
The first works will be civil works in the form of base camps,
access roads, and laydown areas for materials. The Con-
struction Management teamwill act for and on behalf of the
owner and the team will usually consist of a Site Construc-
tion Manager an HSE Manager, a Quality Control Manager
and numerous Site Craft Supervisors and a site Planner.
Quality Management System
Construction quality systems usually follow the International
Standards Organisation (ISO) 9001:2008 format [7]. The
owners demand written documentation defining quality
requirements of every aspect of the new pipeline.
Scheduling of packages
Contractor personnel will maintain a status of the prog-
ress on the completion of package activities when overall
construction progress reaches the 50 % milestone. These
system handover packages will be used to track the comple-
tion of various construction, inspection, or mechanical
completion activities in order to be able to quickly determine
the completion status of any given system.
Punchlists
System punchlists will list items that are incomplete, not
in conformance with the construction documents, or that
require modification.
Contractor will sign-off and advise owner to verify that
the punchlist items have been completed in accordance
with the construction documents.
Handover /Mechanical completion
Handover is the sequence of events leading to transfer
of custody of a system from contractor to owner. It is the
demarcation between the construction phase and commis-
sioning/Start-up operations.
Pre-commissioning [8]
Pre-commissioning activities are associated withmaking the
system ready for operation and will include the following:
• De-watering of residual hydrostatic test water in the
pipeline
• Flushing and dry air blowing of above ground piping and
valve and pigging stations.
• Swabbing of pipeline
• Low pressure leak check (with air) for the above ground
section of the pipelines.
Commissioning procedure [9]
Instrument controls and interlocks are functional as per the
normal operating conditions.
Utilities - Utilities such as power, UPS, water, air, instru-
ment air and HVAC will be checked.
Alarm systems - Setting off alarms and their functioning
will be ensured.
Safety - Identification of possible emergencies and pre-
paredness for its mitigation will be checked.
To clear the pipeline of metallic particles, magnetic clean-
ing will be carried out using a train of brush magnetic pigs.
An intelligent pigging survey will be carried out recording the
entire length in one single run. The report will include a de-
tailed description of the type, size and location of individual
mechanical defects. The repair of defects will be carried out
in accordance with that specified in IS 15663 (Part 1) [9].
The pipeline system needs to be rendered inert using
nitrogen.
The system will be considered to have been commis-
sioned successfully when the pipeline system has run suc-
cessfully for a minimum period of 72 h at stable operating
conditions and instrumentation/control systems, process
utilities and support systems taken on line. Commissioning
documentation records must be kept by the contractor.
Start-up/Runtest
Start-up begins when all system pre-commissioning and
commissioning are completed and accepted by the owner.
Performance guarantee
Contractor will guarantee the performance of all equipment
and material in his supply, based on the ability of the com-
plete system to be able to flow the design volume of gas, at
the design pressure to the discharge location
Challenges involved in constructing a
pipeline
There are a significant number of challenges in the construc-
tion of a pipeline [9], in particular:
• Sustaining the project with the number of resources
required over a long period of time
• Permission from local authorities and construction
notifications
• EIA assessment approvals, in particular wildlife conserva-
tion areas and mitigation plans
• Different sections of a pipeline will have particular issues,
eg, conservation areas
• Pipeline safety can have special conditions that have to
be agreed to as part of the EIA
• During construction, local authorities need to be kept
abreast of any issues that may arise
• Directional drilling at water or road crossings will be
necessary and can be difficult
• Safety in the design of the pipeline is paramount and
needs acute attention
• Trained artisans can be a problem to locate but proper
skills development is essential
• Multiple construction offices and laydown areas along
the pipeline are necessary
• Vendors need to be aware of the importance of materi-
als and equipment deliveries on time and at the right
location.
• Experienced project managers, engineering managers,
construction managers and craft supervisors are essen-
tial to enable a pipeline to be constructed under budget
and on time.
References
A list of references for this article is available from the editor
at
PETROCHEMICALS
Advanced
Software
Platforms reduce
time spent on
routing the pipe-
line to weeks
rather than
months.