How well do you now your pipeline?
PPSA Seminar – Aberdeen
18th November 2009
Paul Birkinshaw
The industry challenge
Choosing the right pigging options
for in-service pipelines
with little or no pigging history
‘Pigging The Unpigged’
(not the unpigabble!)
The challenge for Penspen
Penspen Integrity Have been providing of pigging related consultancy
services for more than10 years
Penspen O&M Services (GreyStar UK) Significant growth area within Penspen in the UK
Providing O&M services for onshore pipelines
Pipeline operators (our clients) with little or no knowledge or experience in pigging
Particularly UK power station gas supply pipelines
We are increasingly being asked to deliver ‘Turnkey Pigging Solutions’
Wearing the operators shoes!
We need to get to know their pipeline intimately
Gathering all the available pipeline data
Collating and carefully assessing the available data
Understand the main drivers (why are we pigging it?)
Defining the key objectives (what do have to achieve?)
Identify the key challenges and uncertainties
Identifying the major constraints
A lot to think about!
What data do we need?
As-built data: Route maps/drawings
Site / AGI plans
P&IDs
Isometric Drawings (usually of AGI plant)
Pipebook / weld records or charts
Construction POs and related procurement documentation
What data do we need?
Operational data Current operating conditions
Historical operating conditions
Suspected or known issues (e.g. evidence of dusts / sludge in filters)
Other useful data sources: Commissioning records (including pigging reports)
Construction reports
Third party incidents
Repair and maintenance records
Why do we need it?
Good ILI data is essential
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2c/(Rt)^0.5 (normalised defect length)
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1.0
d/t
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epth
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DESIGN PRESSURE (72 percent SMYS)
HYDROTEST PRESSURE (100 percent SMYS)
Safety Margin
Repair
Rejection
Acceptance
Getting hold of the data
Review the data from proposal stage
Often limited to diameter, length, service, location
Send an initial data request (the pipeline questionnaire)
The first sign of trouble!
Getting hold of the data Follow-up with meeting and site survey
To establish what's really on site (the AGI equipment)
To find out more about the buried pipeline
Your first introduction to the clients Data Room!!
The data room!!
Getting your head around your client’s document management system can sometimes be difficult!
Preparing for an ILI operation
Preparations Confirming pigging feasibility – can you get a pig
through the line ? o check bores, bends, tees, line pipe data etc.
Verifying the operating conditions are adequate for piggingo flow rate, pressure, temperature etc.
Identifying the pipeline the necessary pipeline preparations or adaptationso access arrangements, fitting temporary traps , bridle
pipework etc.
Preparing for an ILI operation
Setting out the scope of work Defining the overall objectives
Identifying the requirements for the preparatory pigging (pig selection and sequencing of pig runs)
Choosing the right ILI services (geometry, metal loss inspection etc.)
Identifying any ancillary services required (pig tracking / location etc.)
Identifying all general site services required (manning, lifting, handling, tools, waste management etc.)
Preparing for an ILI operation
Procuring the equipment and services Preparing specifications and procurement of all prep
pigs and associated services
Preparing ILI technical and contract requirements specifications
Preparing and administering an ITT for ILI services
Performing tender evaluation (technical and commercial)
Selecting and procuring ILI services (in conjunction with client)
Preparing for an ILI operation
Executing the services at site Preparing method statements and operating
procedures
Risk assessment
Checking the serviceability of the existing pipeline equipment
Carrying out the site preparations
Provision of operators (to operate valves and run pigs)
Provision of all ancillary and general services
Carrying out preparatory pigging
Management of and supporting the ILI pigging
Provision of pig cleaning equipment and waste handling
Preparing for an ILI operation
Delivering the final results Providing a preliminary assessment based on the ILI
preliminary report)
Reviewing the pipeline inspection report
Delivering a integrity integrity assessment
Having access to reliable pipeline data for all stages of the project is essential!
Penspen approach
We start with a ‘Piggability Study’
We basically take our time to gather, properly collate and to assess all the available pipeline data before embarking on a pigging campaign
This has been found to be essential, particularly for turnkey jobs…
….even if the job looks to be straight forward!
The piggability study – the questions
Can the pipeline be pigged?
What do we know about the pipeline? As built data
Operational data
Construction / commissioning records
Operational history
What preparations (or adaptations) are required?
Serviceability of existing facilities
Adaptations (fitting temporary traps etc.)
Adjustments in operating conditions
What are the operational constraints?
The piggability study – the questions
What are the notable pipeline features? Connections
Major crossings (e.g. road, rail, water)
What kind of ILI is required? To facilitate a full integrity assessment
Which pig(s) to start with? Proving and gauging
How much cleaning?
How much contingency?
The piggability assessment provides..
A piggability assessment report
For the client and ourselves
An assessment summary An overview of the issues
A pipeline data file (collating all the relevant data)
For the client and to disseminate within the project team
The data drives everything!
Piggability study – key outputs
Confirm pigging feasibility (hopefully!)
Identify any necessary pipeline adaptations and modifications
Identify any areas of uncertainty for further investigation
Scope out the appropriate preparatory pigging operations and related tasks
Collate key technical data for pig selection and specification
Identify the key requirements for ILI pigging (the ILI service requirements specification)
Piggability study – outputs
Identify any appropriate ancillary services (e.g. pig tracking)
Develop a project plan for the operations
Provide key input data for the development of method statements and reliable operational procedures (none routine procedure)
Provide a sound basis for risk assessment and the development of mitigation measures
Provide valuable input data for ILI data analysis process the final integrity assessment
Power station gas supply pipelines
Owned by power station operator
Utility companies or private operators
High pressure lines Connected to NTS
With or without PRS
Continuous operation Must keep the generators
going
Often no alternative source of gas supply
Sole grid connection
Power station gas supply pipelines
No operational pigging
No permanent pigging facilities
Usually facility to install temporary traps
Limited operator knowledge
Not core business / O&M contracted out
Lack of confidence in (or availability of) pipeline as-built records
24” example (turnkey project)
HDD Crossing800m / 19.1mm pipe / 16m deep
High Gas Flows (3.5 m/s)
Doubts about final routing (fabricated bends?)
No records of any commissioning pigging
Concerns about debris (dust / liquids build up)
Daily revenue from pipeline £1.2M!
Horizontal Directional Drilling (HDD)
24” Receive pipework
24” example
HDD Crossing800m / 19.1mm pipe / 16m deep
High Gas Flows (3.5 m/s)
Doubts about final routingFabricated bens?)
No records of any commissioning pigging
Concerns about debris (dust / liquids build up)
Cautious progressive approach to pigging / early geometry pig run (+ bend detection)
Concerns reduced through further investigations
Key input to requirements specification (ILI tool capabilities
After the ILI pig run…
Forged Bends
Pipe Joints
Using the ILI mapping data
Piggability study – benefits
Confirming the adequacy of all launch and receive facilities
Pig trap requirements
Access issues
Confirming the arrangement s of the existing AGI pipework
Quantify the full range of pipe thickness and bores
Optimum sizing of pigs and sealing elements
ILI service specifications
Piggability study – benefits
Identifying the location and configuration of all major infrastructure crossings locations
For risk management and emergency response planning
Identification of significant geometrical features including known minimum bend radius
For correct pig selection,
Pig configurations
Sequencing of pig runs (pipeline proving)
Piggability study – benefits
Identification of potential debris sources and contaminants
For correct pig selection,
Evaluating risk to downstream plant and for
Preparedness at the receive end (pig cleaning and debris handling)
Sound procurement Getting the right equipment and service levels (quality
control)
Managing financial risk
Piggability study – benefits
Reliable planning and execution Managing risk and QHSE
Delivering effectively and to time and budget
Reliable data analysis and reporting Eliminating uncertainties in the data
Getting more out of the data
Assuring pipeline integrity
Summing up
Access to good pipeline records is key to successful pigging
Increased effectiveness Choosing the right pigs
Selecting the right ILI services
Get the most out of the results
Increased efficiency Get it right first time
Avoiding mistakes
Take out unnecessary conservatism
Reduced risk
Smart pigging requires a smart approach!