Pipeline Overview

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A pipeline is a most economical mean of transporting liquids and gases over long distances. Although they require high initial capital investment, they far more than compensate for the expenses made during their construction.

Index

  1.  About  Pipelines
  2. Types of Pipelines.
  3. Major Advantages of Pipelines.
  4. Disadvantages of Pipelines.
  5. Construction Methodology.
  6. Tenders to Float
  7. Material Procurement
  8. Recent Developments.
  9. Cost Breakup for a Pipeline Project
  10. Stages of Pipeline Project
  11. Energy Savings Due to Pipelines.
  12. Pipeline Risk Management
  13. Pipeline Quality and Assurance and Control
  14. Pipeline Construction Safety and Environment.

About Pipelines

Pipelines are used for transporation of Gases, Liquids and Solids. Various gases transported are Natural Gas, LPG and LNG. Most commonly transported liquids are Crude Oil, Petrolium products and water. Pipelines are also used for transporation of solids in suspension form e.g. Iron Ore, coal etc. Various petrolium products like Motor Spirit, HSD, ATF etc. are transported by pipelines.

Types of Pipelines

  1. Offshore submarine pipeline laid on sea bed – Marine offloading Terminals and Outfalls.
  2. Onshore cross country pipeline laid 1 meters underground – Trunk Pipelines.
  3. Spur/Branch Pipelines

Major Advantages of Pipelines

Major advantages of pipelines w.r.t. other modes of material transport are low cost of transportation, accessibility to remote areas, less time for transportation. Pipe lines are environment friendly, require least energy requirement and have lowest cost of maintenance. They have minimum impact on land use pattern with negligible loss of product in transit. Their high reliability and multi product transportation facility makes them attractive mode of product transport.

Disadvantages of Pipelines

Major disadvantage of pipelines is their high initial cost. Also there is a problem of dead stock / inventory in pipelines.

Construction Methodology

Various engineering aspects must be taken care of during pipeline construction. These aspects are Quality assurance, Quality Control, Applicable codes and standards, Contractor specifications, HSE Requirements. Requirements of pipeline coating at yard, dumpsite and laying of pipelines needs to be considered.

Tenders to float

Various tenders needs to be floated for pipeline construction. These include Survey Tender, Pipe coating tender, Pipeline Installation Tender etc.

Material Procurement

  1. Line Pipes
  2. Valves and Actuators
  3. Scraper Traps, QOEC, Pig Signallers
  4. Flow Tees and Insulating Joints
  5. Induction Bends
  6. Flow Meters
  7. Pumps and Compressors
  8. OFC Cables

Recent Developments.

  1. Automatic Welding & Automatic UT
  2. Micro-Tunneling for pipeline construction
  3. Internal flow coating on line pipes for gas pipelines
  4. 3LPP coating on High Temperature pipelines

Cost Breakup for a Pipeline Project

Sr.No. Item Description Percentage of Capital Cost
Liquid Lines Gas Lines
1 Survey, ROW and Compensation 2% 1%
2 Line Pipe Steel Cost 33% 45%
3 Main Line Materials 2% 3%
4 Coating of Pipes 11% 6%
5 Main Line Construction 33% 25%
6 Cathodic Protection 1% 1%
7 Telecommunications, SCADA and RCPs 5% 2%
8 Pump / Compressor Stations 5% 12%
9 Delivery Terminal Facilities 2% 1%
10 Project Management 5% 4%
  SubTotal 100% 100%

 Stages of Pipeline Project

  1. Conceptualization
    1. Establish Requirement
    2. Evaluate Alternatives
    3. Finalize the Concept
  2. Feasibility Study
    1. Pipeline route Study and Selection
    2. Hydraulic Studies and Optimization
    3. Establish Project Cost
    4. Project Implementation Scheme
    5. Environmental Impact Assessment and Risk Analysis
  3. Basic Engineering
    1. Process Design and Sizing
    2. Optimization Studies
    3. Route Surveys and Investigations
  4. Detailed Engineering
    1. Engineering Design basis
    2. Route Engineering and Engineering Analysis
    3. Specifications and Job Standards
    4. Engineering for Procurement
    5. Installation Engineering and Construction Procedures

Energy Savings Due to Pipelines.

Sr.No. Transportation Mode Energy Consumption in Percentage of Energy Transported
1 Liquid Pipelines 0.5
2 Liquid -> Coastal Transportation 0.8
3 Liquid  ->Trains Transportation 1
4 Liquid -> Trucks Transportation 3.2
5 Coal -> Trains 0.8
6 Coal -> Coastal 1.1
7 Natural Gas Pipelines 2

Pipeline Risk Management

  1. The risk associated with the pipeline, in terms of the safety of people, damage to the environment, and loss of income, depends on the expected failure frequency and the associated consequence, which is directly related to the type of fluids transported and the sensitivity of locations of the pipeline.
  2. In this context, pipeline failures are defined as loss of containment.
  3. The potential pipeline failures, causes and their consequences, should be inventorised and taken into account in the design and the operating philosophy.
  4. The most common pipeline threats which may lead to the loss of technical integrity are given below.
    1. Internal corrosion and hydrogen induced cracking (HIC).
    2. Internal erosion.
    3. External corrosion and bi-carbonate stress corrosion cracking.
    4. Mechanical impact, external interference.
    5. Hydrodynamic forces.
    6. Geo-technical forces.
    7. Growth of material defects.
    8. Over pressurisation.
    9. Thermal expansion forces.
  5. Notwithstanding the requirements of the ANSI/ASME B31.4/8 , the factors which are critical to public safety and the protection of the environment should be analysed over the entire life of the pipeline, including abandonment.
  6. The risk should be reduced to as low as reasonably practicable, with the definite objective of preventing leaks.
  7. The level of risk may change with time, and it is likely to increase to some extent as the pipeline ages.

Onshore Pipelines

A formal quantitative   risk  assessment   (QRA) should be carried out in the following   situations   with   the   location   classes   as   defined in (3.3.3):

    1. Fluid category  B  and  C  in  location classes 3 and 4.
    2. Fluid category D in all location classes.
  1. The assessment  should  confirm  that  the selected    design    factors    (3.4.1)    and proximity distances (3.3.4) are adequate.

 Offshore Pipelines

A formal quantitative risk assessment (QRA) shall be carried out for pipelines connected to permanently manned offshore complexes, except for pipelines transporting category A fluids. The   necessary   riser protection  and  safety  systems  shall  be derived from this assessment.

  1. The risk depends firstly on the expected frequency of failure, due to internal and external corrosion, external loading (e.g. impacts, settlement differences, free spans), material or construction defects, and operational mishaps.
  2. Secondly, it depends on the consequences of the failure, based on the nature of the fluid in terms of flammability, stability, toxicity and polluting effect, the location of the pipeline in terms of ignition sources, population densities and proximity to occupied buildings, and the prevailing climatic conditions.
  3. The expected frequency of failure and the possible consequences may be time-dependent and should be analysed over the entire life of the pipeline.
  4. Risks levels can be reduced by using lower design factors (e.g. higher wall thickness or stronger steel),  rerouting,  providing additional protection  to  the  pipeline, application of facilities to minimise  any released fluid volumes, and controlled methods of operation, maintenance and inspection.
  5. NOTE: Pipelines with a wall thickness lower than 10 mm  are susceptible  to penetration, even by small mechanical excavators. External interference by third parties is a major cause of pipeline failures. Specific precautions against this type of hazard should be addressed; this is particularly relevant to onshore pipelines transporting category C and D fluids.

Environmental impact assesments

  1. An environmental impact assessment (EIA) shall be carried out for all pipelines or groups of pipelines.
  2. EIA is a process for identifying the possible impact of a project on the environment, for determining the significance of those impacts, and for designing strategies and means to eliminate or minimise adverse impacts.
  3. An EIA should consider the interaction between the pipeline and the environment during each stage of the pipeline life cycle.
  4. The characteristics of the environment may affect pipeline design, construction method, reinstatement techniques, and operations philosophy.

Economic risk.

  1. The economic risk is associated with deferment of income, cost of repair, and other costs such as liabilities to the public and clean-up costs.
  2. The economic risk should be evaluated for each phase of the pipeline operating life, and should be compatible with the overall objectives of the Principal.
  3. For the predicted life cycle conditions, the design shall take due account of operations, inspection and maintenance requirements, as well as established operating philosophy and practices, agreed  in  advance  with  the  personnel  responsible  for  the  operation  of  the pipeline.
  4. These include manning levels for the operation, integrity monitoring and maintenance of the pipeline system, the requirements for telecommunications and remote operations, means of access to the onshore right of way, etc.
  5. The design of pipelines which are continuously in operation should address the requirement for bypass at components which need regular maintenance.

Pipeline Quality and Assurance and Control

  1. Review and Approval of Contractors QAP for all activities.
  2. Review and Approval of Contractors Inspection and Test Plans (ITP’s) with reference to standard ITP’s of EIL before start of work.
  3. Review and approval of job procedures and inspection formats based on ITP’s for all pipeline activities.
  4. Quality audits and resolution of non-conformances (NC’s) observed during execution of work and quality audits.

Pipeline Construction Safety and Environment.

  1. During all stages of the pipeline construction, the Contractor shall work to the highest achievable safety and environmental standards.
  2. The safety performance of all staff involved in the work shall be monitored and recorded.
  3. Regular safety inspection of the construction sites shall be carried out, to ensure compliance with the relevant procedures, as well as maintaining awareness of all staff regarding potential hazards.
  4. The aspects related to the management of safety during the construction phase are covered in Shell Standard EP 55000 Sections 15 and 16.

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