POF 2016 In-Line Pipeline Inspection Specifications (PDF)

Specifications and requirements for in-line inspection of pipelines Version 2016  Specifications and requirements for in-line inspection of pipelines - Version 2016 Contents 1 Introduction...............................................................................

Specifications and requirements for in-line inspection of pipelines Version 2016  Specifications and requirements for in-line inspection of pipelines - Version 2016 Contents 1 Introduction..................................................................................................................................... 3 2 Definitions and abbreviations......................................................................................................... 4 2.1 General.................................................................................................................................... 4 2.2 Definitions............................................................................................................................... 4 2.3 Abbreviations.......................................................................................................................... 9 2.4 Parameters and interaction of anomalies............................................................................. 11 2.4.1 Metal loss...................................................................................................................... 11 2.4.2 Dent............................................................................................................................... 13 2.4.3 Gouge............................................................................................................................ 14 2.4.4 Ovality............................................................................................................................ 14 2.4.5 Buckle............................................................................................................................ 14 2.4.6 Ripple/Wrinkle............................................................................................................... 15 2.4.7 Roof topping/peaking.................................................................................................... 16 2.4.8 Crack and crack-like....................................................................................................... 16 2.4.9 Crack colonies................................................................................................................ 17 2.5 Nomenclature of features..................................................................................................... 17 2.6 Anomaly assessment............................................................................................................. 18 2.6.1 Interaction rules............................................................................................................ 18 2.6.2 Indication of anomaly severity (ERF)............................................................................. 18 2.7 Resolution of measurement parameters.............................................................................. 19 3 Health and safety.......................................................................................................................... 20 3.1 ATEX....................................................................................................................................... 20 3.2 IECEx...................................................................................................................................... 21 4 Tool specifications......................................................................................................................... 22 4.1 Introduction........................................................................................................................... 22 4.2 Tool data sheets.................................................................................................................... 22 4.3 Tool class history................................................................................................................... 22 4.4 Tool performance specification............................................................................................. 23 4.4.1 General.......................................................................................................................... 23 4.4.2 Basis of performance..................................................................................................... 24 4.4.3 Exclusions and limitations............................................................................................. 24 4.4.4 Access to supporting performance information........................................................... 25 4.5 Tool performance verification............................................................................................... 25 Pipeline Operators Forum – www.pipelineoperators.org - 1 -  Specifications and requirements for in-line inspection of pipelines - Version 2016 4.6 Changes to tool specification or performance specification sheets..................................... 25 5 Personnel qualification.................................................................................................................. 26 6 ILI preparation and contracting..................................................................................................... 27 6.1 ILI preparation....................................................................................................................... 27 6.2 Contracting............................................................................................................................ 27 7 Reporting....................................................................................................................................... 28 7.1 Operations report.................................................................................................................. 28 7.2 Preliminary report................................................................................................................. 29 7.3 Final report............................................................................................................................ 30 7.3.1 Pipe tally........................................................................................................................ 30 7.3.2 List of anomalies, clusters, data loss and other lists..................................................... 30 7.3.3 List of components........................................................................................................ 31 7.3.4 Summary and statistical data........................................................................................ 31 7.3.5 Performance.................................................................................................................. 33 7.3.6 Dig sheet........................................................................................................................ 33 7.3.7 Software and signal....................................................................................................... 33 7.3.8 Anomaly ranking method for ERF................................................................................. 34 7.3.9 Detection of markers..................................................................................................... 34 7.3.10 Personnel qualification.................................................................................................. 34 7.4 Raw data report..................................................................................................................... 34 7.5 Multiple run comparisons report.......................................................................................... 34 7.6 Experience report.................................................................................................................. 35 7.7 Additional reporting.............................................................................................................. 35 8 References..................................................................................................................................... 36 Appendix 1: ILI companies that provided comments to the draft version of these specifications...... 37 Appendix 2: Guideline to clients for defining specific details of the POF specifications...................... 38 Appendix 3: Report structure, terminology and acronyms................................................................... 42 Appendix 4: Detailed tool data sheet requirements............................................................................. 44 Appendix 5: Tool technology performance specifications.................................................................... 47 Appendix 6: Typical example of Pipe tally*........................................................................................... 53 Appendix 7: Typical example List of anomalies*................................................................................... 54 Appendix 8: Typical example List of clusters*....................................................................................... 55 Appendix 9: Typical example Run comparison overview*.................................................................... 56 Pipeline Operators Forum – www.pipelineoperators.org - 2 -  Specifications and requirements for in-line inspection of pipelines - Version 2016 1 Introduction This document specifies the advised operational and reporting requirements for tools to be used for geometric measurement, mapping, metal loss, crack or other anomaly detection during their passage through pipelines. The tools may pass through the pipeline driven by the flow of a medium or may be towed by a vehicle or cable. The tools may be automatic and self-contained or may be operated from outside the pipeline via a data and power link. This document has been reviewed and approved by the Pipeline Operator Forum (POF). It is stated however, that neither any of the member companies of the POF nor their representatives can be held responsible for the fitness for purpose, completeness, accuracy and/or application of this document. A draft version of this document has been sent for comments to in-line-inspection Contractors as listed in Appendix 1. The POF like to thank the Contractors for their constructive feedback. This document is intended to serve as a generic in-line-inspection specification and therefore cannot cover all pipeline or pipeline operator specific issues. POF members and other users of this specification are therefore free to add or change requirements that should be based on their specific pipeline situation. To support the pipeline operator in specifying/detailing optional items in this document, a guideline with a short description of these items is given in Appendix 2. Comments on this specification and proposals for updates may be submitted to the Administrator at [email protected] with the form which is available on the POF website (www.pipelineoperators.org). Pipeline Operators Forum – www.pipelineoperators.org - 3 -  Specifications and requirements for in-line inspection of pipelines - Version 2016 2 Definitions and abbreviations 2.1 General During the update of this specification, reference to standards such as API 1163 and PDAM1 have been reviewed and some terminology has been aligned. However, if referenced standards are in conflict with this (POF) specification, this specification prevails. If the word "shall" is used in this document it indicates a requirement. If the word "should" is used in this document it indicates a recommendation. 2.2 Definitions Anomaly/feature definitions are provided in such manner that the ILI vendor can identify them accurately, e.g. general reporting like metal loss and deformation is not sufficiently detailed. For the purpose of this document, the following definitions apply: Above Ground Marker: A device, on the outside of and close to a pipeline, that detects and records the passage of an ILI tool or transmits a signal that is detected and recorded by the tool. Reference magnets can be applied to serve identical purposes. Anomaly: An indication, detected by in-line inspection, of an irregularity or deviation from the norm in pipe material, weld material or coating, which may or may not be an actual flaw. Arc strike : Localised point(s) of surface melting caused by arcing between a welding electrode or ground and the pipe surface. The defect formed is a surface depression which may be associated with a local increase in hardness. Blister : A raised spot on the surface of the pipe caused by expansion of gas in a cavity within the pipe wall. Buckle : A local geometric instability causing ovalisation and flattening of the pipe as a result of excessive bending or compression with possibly abrupt changes in the local curvature, which may or may not result in a loss of containment. Note: Buckle to be defined in detail for reporting as Global, Local or Propagation, see below. Buckle arrestor: A device or element in the pipeline with high wall thickness that will act to stop the advance of a propagating buckle. Buckle, global or Global buckle : A Global Buckle will typically involve several pipe joints. It can be horizontal or vertical. Buckle, local or Local buckle : A Local Buckle is a mode causing gross deformation of the pipe cross section, also known as pipe wall buckling. Collapse, 1 PDAM is only used as a reference for definitions Pipeline Operators Forum – www.pipelineoperators.org - 4 -  Specifications and requirements for in-line inspection of pipelines - Version 2016 localised wall wrinkling and kinking are examples of local buckling. Buckle, propagation or Propagating Buckle : A Propagating Buckle is the result of a dynamic process whereby a local buckle propagates along the length of the pipeline. A propagating buckle cannot initiate unless a local buckle has occurred. Casing: A type of feature consisting of a larger diameter pipe placed concentrically around the pipeline, usually in high stress areas such as road crossings or otherwise protecting the pipe from mechanical damage. Certainty: The probability that the characteristics of a reported anomaly are within the stated tolerances. Characteristic : A physical descriptor of a pipeline e.g. grade, wall thickness, manufacturing process or type, size, shape of an anomaly. Client : An organisation that owns and/or operates the pipeline facilities. Cluster: Two or more adjacent anomalies in the wall of a pipeline or component of a pipeline that may interact to weaken the pipeline more than either would individually. Colony : A grouping of stress corrosion cracks (cluster) occurring in groups of a few to thousands of cracks within a relative confined area. Combined features: Features that appear at the same location but at different (inner and outer) surfaces. Component : Any physical part of the pipeline, other than line pipe, including but not limited to valve, weld, tee, flange, fitting, tap, branch connection, outlet, support, anchor, above ground marker, anode, repair, additional metal and wall thickness change. Contractor : Any organisation providing ILI services to Clients. Corrosion: An (electro)-chemical reaction causing loss of metal. Corrosion Resistant Alloy (CRA): An alloy with increased corrosion resistance which may contain metals such as: chrome, cobalt, nickel, iron, titanium, molybdenum. Corrosion related to CRA: Corrosion between carbon steel and CRA affecting the interface. Crack: A planar, two-dimensional anomaly feature with a high length to width ratio, a sharp root radius and a possible displacement (surface opening) < 0.1 mm of the fracture surfaces. Pipeline Operators Forum – www.pipelineoperators.org - 5 -  Specifications and requirements for in-line inspection of pipelines - Version 2016 Crack-like An anomaly feature similar to a crack with some volume and a displacement (surface opening) between 0.1 and 1.0 mm of the fracture surfaces but that might not have a sharp root radius. Debris: Extraneous material in a pipeline. Deformation: A plastic change in shape in the steel pipeline. Note: Deformations are to be reported as e.g. bend, dent, ripple/wrinkle, buckle or ovality, see below. Dent: A local plastic or elastic deformation of the pipe wall resulting in a change of the internal diameter caused by an external force. Note: Dents to be defined in more detail for reporting as Kinked, Plain or Complex Dent, Complex A dent which causes a smooth change in curvature of the pipe wall that contains an anomaly (such as e.g. gouge, corrosion loss, crack) and/or is associated with an adjacent girth, spiral or seam weld. Dent, Kinked : Dent with an abrupt change in the curvature of the pipe wall if any radius of curvature in the dent is ≤ 5 times the wall thickness. This type of dent might also be associated with wall thickness reduction or crack. Dent, Plain : A dent which causes a smooth change in curvature of the pipe wall that contains no wall thickness reduction (such as gouge, crack, corrosion) and is not associated with an adjacent girth, spiral or seam weld. Detection threshold: Minimum detectable feature dimension at a certain certainty. Feature: Component or anomaly in a pipeline detected by in-line inspection. Geodetic Datum 3D coordinate system. Note: the World Geodetic System (WGS84) is commonly used, but others include ETRF89, NAD83, NAD27, RGF93 and more. Gouge: A surface damage with elongated grooves or cavities caused by mechanically displaced or removed material from the pipe wall by interference with a foreign object. Grinding: Wall thickness reduction by removal of material by hand filing or power disk grinding. Heat affected zone (HAZ): The area around a weld where the metallurgy of the metal is altered by the rise in temperature caused by the welding process, but this is distinct from the weld itself. For the purpose of this specification it is considered to be within 2t with a minimum of 20mm. Pipeline Operators Forum – www.pipelineoperators.org - 6 -  Specifications and requirements for in-line inspection of pipelines - Version 2016 In-Line Inspection (ILI): Inspection of a pipeline from the interior of the pipe using an In-Line Inspection tool. In-Line Inspection (ILI) tool: Device or vehicle, also known as an intelligent or smart pig that uses a non-destructive testing technique to inspect the pipeline from the inside. Interaction of anomalies: Two or more adjacent anomalies in the wall of a pipeline or component of a pipeline that may interact to weaken the pipeline more than either would individually. Joint: Single section (also pipe spool) of pipe that is circumferentially welded to form a pipeline. Lamination : Internal metal wall separation creating layers generally orientated parallel to the pipe wall. Lap: A flap of metal that has been rolled or otherwise worked against the surface of the metal but is not fixed, usually with a trapped residue of oxide or scale beneath it. Mapping: Recording of the 3D pipeline route using the inertial navigation system of the ILI tool. Maximum allowable operating pressure : The maximum allowable operating pressure (MAOP) is a pressure less than or equal to the design pressure and represents the maximum allowed pressure during normal operation. Metal loss : Any volumetric pipe anomaly in which metal has been removed. Note: Metal loss to be reported as e.g. corrosion, gouging, grinding or mill anomaly. Measurement threshold: The minimum dimension(s) of a feature to make sizing possible. Mill anomaly: An anomaly that arises during manufacture of a pipe joint or component. Note: Mill anomalies to be reported as e.g. lap, sliver, lamination, non-metallic inclusion, grinding roll mark or arc strike. Ovality : Out-of-roundness of the pipe joint, defined in terms of the difference between the maximum and minimum internal diameter of the pipe joint. Pinhole: Localized corrosion with surface dimensions smaller than 1t or 10 mm whichever is greater in length and width direction. Pipeline: A system of joints and other components used for the transportation of products. A pipeline extends from launcher tool trap to receiver tool trap, including the tool traps, or, if no tool trap is fitted, to the first isolation valve within the Pipeline Operators Forum – www.pipelineoperators.org - 7 -  Specifications and requirements for in-line inspection of pipelines - Version 2016 plant boundaries or a more inward valve if so nominated and designed to a pipeline design code. Pitting: Localized corrosion of a metal surface that is confined to small areas and takes the form of cavities called pits, but are larger than pinholes. Note: The dimensions of pitting are defined in detail further in this document. Probability of Detection: The probability of detection is the probability that a specified feature will be detected by the ILI tool. Note: The level of probability to be used is defined in detail further in this document. Probability of Identification: The probability that a detected anomaly or feature will be correctly identified. Processed raw data: Data gathered from ILI tool sensors and passed through one or several filtering algorithms e.g. corrected for odometer slippage. Raw data: Unprocessed data from all sensors attached to the respective inspection tool during a pipeline inspection. Reference magnet: A permanent magnet placed on the pipeline with known location and/or coordinates used to correlate the inspection data. See also Above Ground Marker. Reporting threshold: A parameter, which defines whether or not an anomaly will be reported. Ripple/Wrinkle: A smooth local plastic, mainly circumferential orientated, deformation on the out and/or inside wall of the pipe caused by bending stresses. For a wrinkle, the peak-to-valley distance is greater than a ripple. Roll mark : Markings on the pipe surface resulting from the plate or pipe rolling process used for spirally or longitudinally seam welded pipe. Roof topping/peaking : Incorrect forming of the plate edges into the pipe curvature during fabrication, resulting in meeting of the edges as a triangular apex with the seam weld projecting beyond the circular contour of the pipe, also called peaking or angular misalignment. Sizing accuracy: Sizing accuracy is given by the interval with which a fixed percentage of features will be sized. This fixed percentage is stated as the certainty level. Sliver : A thin elongated piece of metal rolled into the surface of the pipe, often metallurgically attached at one end. Sometimes reported as lap or lamination. Pipeline Operators Forum – www.pipelineoperators.org - 8 -  Specifications and requirements for in-line inspection of pipelines - Version 2016 Strain Geometrical, non-dimensional measure of deformation representing the relative displacement between particles in a material body. Trap, launcher/receiver: An ancillary item of pipeline equipment, with associated pipe work and valves, for introducing an ILI tool into a pipeline (launcher trap) or removing an ILI tool from a pipeline (receiver trap). Wall thickness, Measured: The average of measured, un-corroded wall thickness values that is representative for a whole pipe joint/component. Wall thickness, Nominal: The wall thickness required by the specification for the manufacture of the pipe. Wall thickness, Reference: The actual undiminished wall thickness surrounding a feature, used as reference for the determination of the feature depth. Weld: The area where joining has been realised by welding. This is distinct from the heat-affected zone, but is located within it. Weld anomaly: Anomaly in the body or the heat affected zone of a weld. Weld affected area: Area on both sides of a weld where ILI measurements are affected by the geometry of the weld. See also "Heat affected zone". 2.3 Abbreviations For the purpose of this document, the following acronyms apply: A A geometrical parameter used to specify the dimension class of metal loss anomalies detected by in-line inspection of a pipeline and further defined in Figure 2.1 of this document. AGM Above Ground Marker CRA Corrosion Resistant Alloy d Depth of metal loss E End point of anomaly EC Eddy Current EMAT Electro Magnetic Acoustic Transducer ERF Estimated Repair Factor GIS Geographic Information System GNSS Global Navigation Satellite System GPS Global Positioning System h Height or depth of Wrinkle/Ripple/Dent or Roof topping HAZ Heat Affected Zone Pipeline Operators Forum – www.pipelineoperators.org - 9 -  Specifications and requirements for in-line inspection of pipelines - Version 2016 ILI In-Line Inspection IMU Inertial Mapping Unit ID Internal pipe Diameter l Length of anomaly/feature dimension in the axial direction and length of cracks in any direction MAOP Maximum Allowable Operating Pressure MOP Maximum Operating Pressure MFL Magnetic Flux Leakage NDE/NDT Non-Destructive Examination/Non-Destructive Testing OD Outer pipe Diameter PDAM Pipeline Defect Assessment Manual POD Probability Of Detection POI Probability Of Identification Psafe Safe operation pressure as per calculated defect assessment method R Internal pipe Radius S Start point of anomaly SCC Stress Corrosion Cracking t Wall thickness UT Ultrasonic Testing w Width of anomaly/feature in the circumferential direction and opening dimension for crack-like features WGS 84 World Geodetic System 1984 Pipeline Operators Forum – www.pipelineoperators.org - 10 -  Specifications and requirements for in-line inspection of pipelines - Version 2016 2.4 Parameters and interaction of anomalies 2.4.1 Metal loss The parameters of anomalies are length "l", width "w" and depth "d". The starting point, S, and the dimension of an anomaly are defined as illustrated in Figure 2.1 looking in the ILI run direction. Start and end points are diagonally in a rectangle enclosing the anomaly. The depth represents the deepest point reported within the rectangle. Figure 2.1: Illustration of parameters describing location and dimension of metal loss feature. Pipeline Operators Forum – www.pipelineoperators.org - 11 -  Specifications and requirements for in-line inspection of pipelines - Version 2016 The start position of the anomaly has a lower clock position than the end position. Anomalies crossing the 0:00 o’clock position have a higher clock position at the start. Full circumferential anomalies are reported with S at 0:00 o’clock. Note: highest clock position shall be 11:59. Metal loss anomaly classification The measurement capabilities of non-destructive examination techniques, in particular the MFL technique, depend on the geometry of the metal loss anomalies. Metal loss anomaly classes have been defined as shown in Figure 2.2 for anomaly reporting purposes. In addition it allows for a proper specification of the measurement capabilities of MFL ILI tools. Each anomaly class permits a large range of shapes. Within that shape a reference point/size is defined at which the POD for MFL tools is specified, see Table 2.1. An even distribution of length, width and depth shall be assumed for each anomaly dimension class to derive a statistical measurement performance on sizing accuracy. Table 2.1: Definition of anomaly dimension class and MFL POD reference point/size Reference point/size for Anomaly dimension class Definition the POD in terms of l x w General: {[w  3A] and [l  3A]} 4A x 4A {([1A  w < 6A] and [1A  l < 6A] and Pitting: [0.5 < l/w < 2]) and not 2A x 2A ([w  3A] and [l  3A])} Axial grooving: {[1A  w < 3A] and [l/w  2]} 4A x 2A Circumferential grooving: {[l/w  0.5] and [1A  l < 3A]} 2A x 4A Minimum dimensions to {[0 mm < w < 1A] and Pinhole: be further defined by [0 mm < l < 1A} Contractor, see table A3-2 Axial slotting*: {[0 mm < w < 1A] and [l  1A]} 2A x ½A Circumferential slotting*: {[w  1A] and [0 mm < l < 1A]} ½A x 2A * Anomalies with a width < 1mm are defined as crack of crack-like which might or might not be metal loss Pipeline Operators Forum – www.pipelineoperators.org - 12 -  Specifications and requirements for in-line inspection of pipelines - Version 2016 The geometrical parameter A is linked to the NDE methods in the following manner:  If t < 10 mm then A = 10 mm  If t ≥ 10 mm then A = t Figure 2.2: Graphical presentation of surface dimensions of metal loss anomalies per dimension class. 2.4.2 Dent A dent is defined by its type (Kinked, Plain, Smooth), maximum depth (h), width and length, as shown in Figure 2.3. If requested, the maximum strain based on a methodology agreed between Client and Contractor. If the dent results in an ovality of the pipe then a more detailed description and evaluation is required. Figure 2.3: Measurement of dent. Pipeline Operators Forum – www.pipelineoperators.org - 13 -  Specifications and requirements for in-line inspection of pipelines - Version 2016 The dent is defined as a percentage of the OD where h is measured from either the inside or outside of the pipe: 2.4.3 Gouge As a gouge can take various forms, a schematic drawing is not available. Gouge anomaly dimensions are defined by the rectangle as shown in Figure 2.1, but the Contractor shall classify them as gouges with the angle related to the pipe axis reported as well. If a gouge is associated with a dent, then it shall be reported as a "Smooth or Kinked Dent with Gouge" with separate dimensions of the gouge and dent. 2.4.4 Ovality Ovality is specified by IDmax and IDmin as shown in Figure 2.4 Figure 2.4: Measurement of ovality at one point over distance. The ovality is defined as the ratio given in the equation below: The ovality reported at the joint is based on a statistical approach of the measurements along the joint. It can be the mean ovality or any percentile (90th is common) or the maximum measured, which is to be detailed by the Client in the contract. If not specified otherwise, the maximum shall be reported. Note: Reporting of ovality dimensions depends on the used formula (code) and it is therefore required that the formula applied is stated in the report. 2.4.5 Buckle As a buckle can take various forms, a schematic drawing is not available. Pipeline Operators Forum – www.pipelineoperators.org - 14 -  Specifications and requirements for in-line inspection of pipelines - Version 2016 2.4.6 Ripple/Wrinkle A ripple/wrinkle is specified by its height and length as shown in Figure 2.5Figure 2.5, Figure 2.6 and Figure 2.7. The maximum values shall be reported and, if requested, also the maximum strain based on a methodology agreed between Client and Contractor. Figure 2.5: Measurement of ripple / wrinkle. Figure 2.6: Measurement of single ripple/wrinkle. A ripple/wrinkle is defined by its length (l) and maximum height (h). Figure 2.7: Measurement of multiple ripple / wrinkle. Multiple ripples/wrinkles are defined by the total length (l) and maximum height (h). Pipeline Operators Forum – www.pipelineoperators.org - 15 -  Specifications and requirements for in-line inspection of pipelines - Version 2016 2.4.7 Roof topping/peaking Roof topping/peaking is specified by the angle 2Ѳ and height (h), see Figure 2.8. Figure 2.8: Measurement of peaking/roof topping. Roof topping/peaking is defined by its height h in mm and angle 2Ѳ in degrees (°). 2.4.8 Crack and crack-like A crack or crack-like feature is specified by the length (l, from tip S to tip E), depth (d) and orientation (angle α) to the pipeline axis, see Figure 2.9. Figure 2.9: Illustration (top view and cross section) of parameters describing location and dimension of crack and crack-like features. Planar, two-dimensional and elongated pipeline features mechanically splitting the pipe wall into two parts and oriented primarily perpendicular to the pipe surface are referred to as cracks or crack-like anomalies depending on the driving cracking mechanism. Cracks are typically oriented either axially in the pipe body, or in the longitudinal, spiral, or circumferential weld areas and welds. Independent from the nature of the cracking mechanism, cracks in pipelines are observed as single or colonies. Pipeline Operators Forum – www.pipelineoperators.org - 16 -  Specifications and requirements for in-line inspection of pipelines - Version 2016 The parameters of single crack and crack-like anomalies are length "l" and depth "d". Due to its planar, two-dimensional nature a crack or crack-like anomaly shows no width but may show a crack opening depending on the geometry and nature of the crack. Cracks are regarded to have an opening at the surface < 0.1 mm, crack like defects to have an opening at the surface of 0.1 mm to 1.0 mm. The capabilities of non-destructive examination techniques to detect, classify and size crack and crack-like anomalies strongly depend on the technology itself and its implementation on the inspection tool. In contrast to metal loss anomalies, no anomaly classes exist for cracks and crack-like anomalies. The Contractor shall provide the tool performance specifications in accordance to section 4.4 and table A5-4 with special emphasis on:  The POD at 90% as a function of the anomaly dimensions.  Details on the basis of the performance shall be clearly presented with regards to artificial and/or natural features. 2.4.9 Crack colonies A crack colony is specified by the length (l), width (w), see Figure 2.10 and depth of the deepest single crack in the colony (see Figure 2.9). Figure 2.10: Illustration (top view) of parameters describing location and dimensions of crack colonies. Colonies of cracks can be formed as a result of corrosion (e.g. SCC) and cracks in such a colony might interact depending on their dimensions, separation and density. Interaction rules are applicable for assessment, see 2.6.1. 2.5 Nomenclature of features Features can be divided into component features and anomaly features. Features shall be identified in accordance with Appendix 3: Report structure, terminology and abbreviations: Column Feature type. The type of features shall be further identified in accordance with Appendix 3: Report structure, terminology and abbreviations: Column Feature identification. Pipeline Operators Forum – www.pipelineoperators.org - 17 -  Specifications and requirements for in-line inspection of pipelines - Version 2016 2.6 Anomaly assessment 2.6.1 Interaction rules Clustering of anomalies will be required if defects can interact and thereby pose a greater risk to the pipeline than individually assessed. The applicable assessment method shall define the interaction rules and clustering requirement. If not specified otherwise by the Client, the latest version of ASME B31G should be used for assessment and interaction rules of metal loss. Possible alternative methods include, but are not limited to: API 579/ASME FFS (general, including metal loss and cracking) Modified ASME B31 G, (metal loss) BS 7910 (general, including metal loss and cracking) DNV RP-F101 (metal loss) Kastner (only circumferential features) CEPA Recommended Practices for Managing Near-neutral pH Stress Corrosion Cracking (only SCC) Pipeline Defect Assessment Manual (PDAM). 2.6.2 Indication of anomaly severity (ERF) To allow the Client to rank the indications of anomalies in the pipeline on the basis of a first pass screening of severity, the Estimated Repair Factor (ERF) can be used. It is noted that for significantly ranked defects a more sophisticated assessment may then be applied. The ERF is defined as: ERF = MAOP/Psafe Psafe is the safe working pressure as calculated by the latest version of an appropriate anomaly assessment method as agreed between Client and Contractor. Psafe shall be calculated using specific information of the pipeline segment such as the measured wall thickness and appropriate design factor for the area class. If not specified otherwise by the Client, the latest version of ASME B31G should be used for metal loss features. For possible alternative assessment methods (but not limited to) see section 2.6.1. Note: The calculation of ERF has been updated from previous versions of this POF specification by replacing MOP with the MAOP. Whereas MOP could be applied as a temporary process restriction, MAOP implies the maximum pressure that could be introduced to the pipeline both at the time of the calculation and for any future operations. Pipeline Operators Forum – www.pipelineoperators.org - 18 -  Specifications and requirements for in-line inspection of pipelines - Version 2016 2.7 Resolution of measurement parameters A list of definitions with resolution and associated units to be used is presented in Table 2.2. Table 2.2: List of definitions with minimum resolution and associated units to be used. Definition SI/metric units Alternative units Log distances 0.001 m 0.01 ft Feature length and width 1 mm 0.01 inch Feature depth 0.1 mm or 1% 0.01”or 1% Reference t 0.1 mm or 1% 0.01” or 1% Orientation 0.5° or 1 minute 1 minute ERF 0.01 0.01 Magnetic field strength (H) 0.1 kA/m 1 Oe (Oersted) Magnetic flux density (B) 0.1 T (Tesla) 103 G (Gauss) Axial sampling distance 0.1 mm 0.01 inch Circumferential sensor spacing 0.1 mm 0.01 inch Tool speed 0.1 m/s 0.1 ft/sec Temperature 1 °C 1 °F Pressure 0.01 MPa/0.1 bar 1 psi 1) Global Position Coordinates 0.01 m 10-8 ° (Decimal degree) 1) Unless specified otherwise, WGS84 shall be used as the coordinate system Pipeline Operators Forum – www.pipelineoperators.org - 19 -  Specifications and requirements for in-line inspection of pipelines - Version 2016 3 Health and safety Care for health and safety is essential during any stage of any activity. As ILI of pipelines typically involves working with pressurized components and potentially explosive, flammable or hazardous atmosphere, adequate procedures must be in place to prevent any harm to personnel, environment or equipment. It is the responsibility of both Client and Contractor to agree on health and safety requirements and procedures and to check if latest and most stringent versions of (local) HSE requirements are met. ILI operations require a pipeline to be opened and an inspection tool to be loaded/unloaded whereby explosive environments might occur. Special measures to prevent unsafe situations during ILI activities shall be taken. Regulations have been developed to prevent accidents due to explosive environments. Examples of these regulations are the ATEX guidelines (ATmosphères EXplosive) which is mandatory for activities in the European Union or the IECEx system (International Electro technical Commission: IEC System for Certification to Standards relating to equipment for use in Explosive Atmospheres). Implementation of ATEX, IECEx or an equivalent directive might be mandatory on the basis of national, local legislation or Client policy and if required shall be employed for ILI operations in addition to already applicable standards and procedures. For use of non-electrical equipment in potentially explosives atmospheres, EN 13463 or an equivalent standard can be applicable. For use of electrical equipment in potentially explosives atmospheres, EN-IEC 60079-xx (-10, -14, -17) or an equivalent standard can be applicable. 3.1 ATEX ATEX zone 1 is considered to be applicable for ILI operations. The Client shall specify if ATEX certification is required and if so, the following two directives shall be followed:  ATEX 1142, Directive 2014/34/EU of the European Parliament and of the Council of 26 February 2014 on the harmonization of the laws of the Member States relating to equipment and protective systems intended for use in potentially explosive atmospheres. For ILI activities in the oil and gas industry it is considered that, unless specific measures are taken, zone 1 (areas with occasional dangerous explosive atmosphere caused by gas, vapour or mist) is typically applicable. Unless the Client specifies otherwise, the ATEX certified ILI tool shall comply with:  Group II: Equipment intended for use in explosive atmospheres other than mines  Category 2: High protection level for use in zone 1  Minimum temperature class T3: Surface temperature of equipment < 200°C (depending on the medium, another temperature class might be required e.g. T4 (.11 MPa during receiving and launching of tools. 3.2 IECEx The IECEx is an alternative code for certification of ILI equipment with equal area of application as ATEX 114, but not further discussed in this specification. Pipeline Operators Forum – www.pipelineoperators.org - 21 -  Specifications and requirements for in-line inspection of pipelines - Version 2016 4 Tool specifications 4.1 Introduction Tool specifications are important for the Client to clearly understand the capabilities and limitations of an ILI tool before selection and use. The purpose of this section is to present a consistent approach for presenting tool specifications and agreed tool specifications shall be part of the contract between Client and Contractor, as further described in chapter 6. Tool specifications typically consist of the combination of tool data sheets and tool performance specification:  Tool data sheets cover the physical dimensions of the tool and operating conditions the tool can work in  Performance specifications describe the inspection capabilities and limitations of the inspection technology applied. Tool performance follows the general requirements of API 1163 supported by Contractor quality systems. The Client should clearly define the goals and objectives of an ILI before tool selection can take place. A key aspect in this process is a proper identification of pipeline threats and anticipated degradation mechanisms. The expected type, size, location and orientation of anomalies are important inputs to tool selection. In many cases tool selection requires a deeper understanding and details of specific tools which can best be obtained in a discussion between Client and Contractor. Factors that may influence tool performance, such as level of cleanliness and pipeline operating conditions need to be considered as well. Prior to an in-line inspection the following should be in place:  The Client to communicate the goal and objectives of the ILI to the Contractor  Tool selection to be discussed and agreed between Client and Contractor  Contractor to confirm that tool selection is appropriate given the goals and objectives of the ILI. 4.2 Tool data sheets Tool data sheets provide information to allow Client to understand the limitations of service and suitability for use in pipeline system. Typically separate tool data sheets exist for each diameter and inspection technology combination. They shall clearly present:  Tool identification  Tool specifications  Safety  Operating conditions/parameters  Pipeline restrictions  Launcher and Receiver trap details. Detailed tool data sheet requirements are included in Appendix 4. 4.3 Tool class history In order to achieve a high probability of first run success (Ref. POF document "Guidance on achieving ILI First Run Success" ), it is important that the Client clearly understands the operating history of Pipeline Operators Forum – www.pipelineoperators.org - 22 -  Specifications and requirements for in-line inspection of pipelines - Version 2016 the tool class and its level of operational testing. Before the ILI contract is confirmed and unless otherwise agreed, Client may request any or all of the following information:  Technology readiness of tool class hardware for operating conditions using the following grades: 1. Newly designed component with limited testing 2. Limited field operation ( < 20 runs or < 500 km distance) 3. Multiple uses with clear history of components and subsequent changes  Provide a unique tool reference number and applicable data sheet. Design changes to tool components or modules that may affect level of readiness shall be clearly communicated to Client both at time of placing order and for any subsequent change made by Contractor. 4.4 Tool performance specification Tool performance specifications shall define the ability of the ILI system to detect, locate, identify, and size pipeline features, components and anomalies. It is typically linked to the inspection technology applied in the tool (e.g. UT, MFL, EC, EMAT or mapping). 4.4.1 General Tool performance specifications shall comply with requirements given in API 1163 , chapter 6. The following general requirements are given for tool performance specifications:  The Probability Of Detection, POD (a), is the probability that a feature with size a will be detected by the ILI tool. Two feature sizes are frequently extracted from the POD information: a90/50 (a90) is the feature size at which the average POD is 90% and a90/95 is the feature size at which the lower 95% confidence limit of the POD is 90%, see also Figure 4.1. In the tool performance specification it shall be clearly specified what POD value is given. It is recommended to specify the POD90/95 value  The Probability of Identification, POI, is the probability that a feature is correctly identified by the ILI tool. The type or types of anomalies, components, and characteristics that are to be detected, identified, and sized by the ILI system shall be clearly indicated. Identification of each feature type shall be reported as specified in Appendix 5, Table A5-1  The measurement specifications for detection and sizing of the various anomalies and pipeline location shall be reported as specified in Appendix 5, Tables A5-2 to A5-8 where they apply. The Client might request to complete the alternative Table A5-3a in favour of Tables A5-2 and A5-3  Performance specification shall clearly state the level of analysis that is required to support the level of specification  Where a higher level of performance is based on more detailed analysis, the additional performance level and commercial basis for additional analysis shall be clearly stated and agreed by Client and Contractor  If different technologies (e.g. MFL, UT, EC or EMAT) are combined into one tool, then the specifications shall be provided as if the technologies were applied in a separate tool and additionally a table with the specifications of the multi-technology tool shall be provided. The performance specification shall define and document the essential variables. In general two types of essential variables should be considered for ILI tool performance: i) pipeline design and Pipeline Operators Forum – www.pipelineoperators.org - 23 -  Specifications and requirements for in-line inspection of pipelines - Version 2016 operational characteristics, ii) inspection tool design and physical characteristics. More detailed requirements on the essential variables are to be included in the performance specifications as listed in Appendix 5. Figure 4.1: Typical example of the average and lower limit POD curve as function of anomaly size with indication of the definitions of a90/50 (a90) and a90/95 4.4.2 Basis of performance The basis on which performance specification is made shall be clearly stated for each feature type using the following:  Modelling only  Limited pull through tests and modelling (where effects of essential variables have not been fully tested by pull through runs and features used are predominantly manufactured)  Extensive pull through tests covering range of speed and wall thickness using a combination of manufactured and natural features  Limited field verification with less than 20 operational runs  Extensive field verification results reviewed on an annual basis. Where multiple methods are used, the Contractor shall clarify what has been used. Details of manufactured and/or natural features shall be clearly presented. 4.4.3 Exclusions and limitations Physical and operational factors or conditions that limit the detection thresholds, PODs, POIs, and sizing accuracies shall be identified in the performance specification. It shall be clearly stated what the acceptable limits are for, but not limited to, e.g. tool speed and pipe wall thickness, see also Appendix 5. Pipeline Operators Forum – www.pipelineoperators.org - 24 -  Specifications and requirements for in-line inspection of pipelines - Version 2016 4.4.4 Access to supporting performance information Contractor shall provide access to information in support of stated tool performance specification on request of Client. The ILI tool testing information of the contractor shall be auditable and contain information regarding the calibration procedure and latest calibration record of the tool. The procedure should give insight in, but not limited to: used calibration features, line pipe material, wall thickness and manufacturing process, tool velocity, date and frequency of calibration. For magnetic tools the calibration information will include the tool speed and the measured magnetic field strength value with the position where it was measured. In addition the Contractor shall supply a definition of which sizing model and revision was used. How and where the information is to be provided is to be agreed between Contractor and Client. It is the responsibility of the Contractor to check that the tool and the calibration methods are valid and adapted to the Client’s objectives. 4.5 Tool performance verification A Client may choose to verify tool performance through formal testing or field verification. In case formal testing is carried out, the report should at least contain the following information:  Details of runs and essential variables tested  Details of features  Comparison of stated performance with actual reported features. Regarding field verification more guidance can be found in POF document “Guidance on Field Verification Procedures for In-Line-Inspection” and API 1163 (chapter 8 and Annex C). In case field verification is performed the following requirements apply:  To ensure meaningful data is collected from the field, Client should facilitate access for Contractor to verify field measurement  Client shall provide Contractor with field verification data (dig data)  Contractor shall use field verification data to confirm tool performance. 4.6 Changes to tool specification or performance specification sheets Changes to tool and performance specifications shall be tracked in Contractor Quality Assurance system. Each revision shall have date and issue number. Where a change could affect earlier pipeline integrity assessment, Client shall be notified of change and potential implications. This typically applies when performance specification for certain features is reduced based on new information or additional testing. Any requirement for reassessment of features as a result of change shall be agreed between Client and Contractor. Pipeline Operators Forum – www.pipelineoperators.org - 25 -  Specifications and requirements for in-line inspection of pipelines - Version 2016 5 Personnel qualification The personnel operating the ILI systems and the personnel handling, analyzing and reporting the inspection results shall be qualified and certified according to ANSI/ASNT-ILI-PQ-2005 (reapproved 2010) or later version/superseding document. Unless the Client specifies otherwise, key personnel shall meet the following minimum qualifications, ref. ANSI/ASNT-ILI-PQ-2005 :  Team leader during ILI field activities: Level II Tool Operator for the applicable technology  Data analysis and reporting Lead: Level II Data Analyst for the applicable technology  Review of final Client report: Level III Data Analyst for the applicable technology. The review should include (but not limited to) e.g. a quality check of data analysis and reported results. An overview of personnel qualifications that will be deployed for the ILI tool run, data analysis and final report review shall be submitted to the Client. The personnel qualifications shall be auditable. Pipeline Operators Forum – www.pipelineoperators.org - 26 -  Specifications and requirements for in-line inspection of pipelines - Version 2016 6 ILI preparation and contracting 6.1 ILI preparation The POF document “Guidance on achieving ILI First Run Success” stresses the importance of the preparation and contracting phases to meet all the objectives of the inspection. The preparation phase is described in length in this document, which includes some check lists in Appendix B. 6.2 Contracting This POF document is intended to serve as a generic ILI specification where details and deviations for ILI runs still need to be defined to serve Client's specific issues. Such details and deviations (Appendix 2 provides guidance), should be agreed between Client and Contractor and stated in the ILI contract. The contract between the Client and the Contractor shall, as a minimum include the following items:  Organization: The organization shall be defined between Client and Contractor, in terms of human and materials resources, communication, schedule of the operations, run conditions, procedures, roles and responsibilities, actions in the event of an emergency etc. The POF document "In-Line-Inspection Check Lists" provides guidance  Specific details: Details and deviations from the POF document "Specifications and requirements for in-line inspection of pipelines" (this document, if applicable)  Run preparation: The Client should supply the Contractor with details of the pipeline(s) to be inspected. The POF document "ILI Pipeline Questionnaire" provides guidance  Operations: The operations shall be defined in terms of pipeline technical data, tool specifications, characteristics and performances, criteria for cleaning and run validation  Results: The results shall be reported as per chapter 7. If requested by the Client, a revised version of the final report shall be issued in case of proven discrepancies between reported information and verifications. The requirements herein may be changed at Client’s request. Some points may depend on the configuration of the network to be inspected, the Contractor, the technology used, the internal (Client) policies and practices and local regulations. It can be considered that, for specific applications, specifications and/or defect geometries, dedicated tool calibration can be performed (e.g. with spare project pipes), followed by a modified interpretation/sizing model. Pipeline Operators Forum – www.pipelineoperators.org - 27 -  Specifications and requirements for in-line inspection of pipelines - Version 2016 7 Reporting Reporting is an essential part of the inspection process and depending on the time and information required by the Client, various types of reports can be issued, see below. If the Contractor finds an anomaly during the inspection and/or evaluation of the ILI data which could be an immediate threat to the integrity of the pipeline, he has the duty to report this to the Client without delay. If not agreed otherwise between Client and Contractor, reporting is based on at least two separate documents:  Operations report  Final report. In addition to the above mentioned reports, one or more of the following reports can be requested and agreed between Client and Contractor:  Preliminary report  Raw data report  Multiple run comparison report  Additional reporting. All documents and all lists (e.g. pipe tally, list of anomalies, etc.) will contain the following general information:  Identification of the Contractor and Client  Identification of the pipeline  Product  Outside or nominal diameter  Length  Construction year  ILI technology/technologies  Inspection date/Reference. 7.1 Operations report The operations report should summarize important operational information such that the Client is informed on the success of the inspection and quality of data collected and should include information on run preparation, running of tool, run quality including pipeline cleanliness to verify if targets are achieved. If data quality is not as required for a successful pipeline feature evaluation, a re-run (if possible) can be considered. This report follows good practices regarding ILI activities as described in the POF document "Guidance on achieving ILI First Run Success". The operations report shall be sent in electronic form to the Client before demobilization of the tool and ultimately within 2 days of the ILI run, unless agreed otherwise. The demobilization of tool and crew shall be agreed between Client and Contractor based on the operations report results using the criteria below. The operations report shall contain, unless agreed otherwise:  Any reported safety observation (e.g. near miss)  A description of the operations (cleaning, gauging, dummy tool run, ILI tool run) including run conditions Pipeline Operators Forum – www.pipelineoperators.org - 28 -  Specifications and requirements for in-line inspection of pipelines - Version 2016  Used tool(s) identification (serial number) with tool(s) data sheet and calibration  AGM statistics (if applicable)  Cleaning results and comparison to criteria  Gauging/dummy tool run results and comparison to criteria  Details of ILI run(s): o Time and date of tool launching and receiving o Travelling time o Min/max tool velocity, and tool velocity plot over the length of the pipeline o Min/max pressure o For MFL tools: min/max magnetization level, and a plot of the magnetic field strength in kA/m over the length of the pipeline measured at the inner surface of the pipe o Condition of tool(s) after receipt e.g. damaged sensors o Data loss statistics from faulty sensors and in case of UT echo loss statistics o Data recording and quality within contract specifications  The suitability of the recorded data to allow a successful evaluation. ,The formulation for acceptable data loss shall be, unless specified otherwise:  Continuous loss of data less or equal to 0.5 % of pipeline length  Discontinuous loss of data less or equal to 3% of pipeline length  Continuous loss of data from less than 4 adjacent sensors or 25 mm circumference (whichever is smallest).  The criteria apply to each section of the pipeline i.e. each diameter, wall thickness and pipe manufacturing process.  If data loss exceeds one of the criteria above, this shall be discussed between Client and Contractor to reveal the cause and decide on follow-up actions which might be: o A re-run of the tool o Check if the data loss has an effect on anomaly detection and sizing capability of the ILI tool. The tool operational data statement shall indicate whether the tool has performed according to specifications and shall detail all locations of data loss and where the measurement specifications are not met. When the specifications are not met (e.g. due to speed excursions, sensor/data loss), the number and total length of the sections shall be reported with possible changes of accuracies and certainties of the reported results. 7.2 Preliminary report A preliminary report is a list of features, including by their dig sheets. The reporting format is as per the list of anomalies in the final report. The preliminary report shall be delivered if requested by the Client or if the Contractor finds an anomaly (or anomalies) during the analysis of the ILI data which might be (are) an integrity threat to the pipeline. The preliminary report aims at summarizing the most important features (individual and clustered) based on Client criteria as defined in the contract, in order to guarantee a safe pipeline operation. Unless agreed otherwise, typical reporting should include:  Features with an ERF ≥ 0.8  Metal loss features ≥ 50% Pipeline Operators Forum – www.pipelineoperators.org - 29 -  Specifications and requirements for in-line inspection of pipelines - Version 2016  Dents, Wrinkles/Buckles ≥5%  Cracks with depth ≥ 4.0 mm. Actual data quality shall be confirmed in terms of:  Reporting threshold  Method of analysis  POD, POI, Sizing accuracy. The preliminary report shall be sent in electronic form to the Client within 4 weeks of the ILI run, unless agreed otherwise. 7.3 Final report Standard criteria for the final report are given in this chapter, but can be changed if agreed between Client and Contractor. The final inspection report (hard and electronic copy) of either a single or combined ILI tool run shall contain the information as described in this chapter and be submitted within 8 weeks of the ILI run, unless agreed otherwise. The reporting thresholds shall (if not specified otherwise) be:  For MFL tools: Metal loss with a depth ≥ 10% t for welded pipe and ≥15% for SMLS pipe  For UT and other tools: Metal loss with a depth ≥ 1.0 mm  Cracks with a length ≥ 25 mm  Dents, ripples/wrinkles with a height/depth ≥ 1% ID  Ovalities ≥ 5% ID. 7.3.1 Pipe tally The pipe tally shall be a listing of all pipeline component features and anomaly features and should be reported in accordance with a typical report structure as given in Appendix 6 (including terminology, see Appendix 3 "Feature identification"). The Client can specify the pipe tally to specific requirements, e.g. add or delete specific columns. The pipe tally shall be compatible with standard files such as CSV, ODS or another agreed format. 7.3.2 List of anomalies, clusters, data loss and other lists Unless specified otherwise by the Client, the following lists shall be provided:  List of anomalies: The list of anomalies shall contain the anomalies which are clustered if required by the interaction rules (according to chapter 2.6.1), with dimensions above the reporting threshold at POD=90% or above a reporting threshold as specified by the Client (including terminology, see Appendix 3). For a typical example see Appendix 7. Note: if no defect interaction rule is applied, then this list can be waived in favour of the "List of individual anomalies", see below.  List of clusters: The list of clusters (according to chapter 2.6.1) shall contain the clusters and the individual anomalies that are part of the cluster. It shall be clearly indicated what anomalies form a certain cluster. For a typical example see Appendix 8.  List of individual anomalies: Pipeline Operators Forum – www.pipelineoperators.org - 30 -  Specifications and requirements for in-line inspection of pipelines - Version 2016 The list of individual (all) anomalies shall be a listing of all anomalies without applying a defect interaction rule and with dimensions above the detection threshold at POD=90% or above a reporting threshold as specified by the Client.  List of data loss: The list of data loss shall be a listing of all locations with data loss indicating the cause of data loss. (Note: as data loss might be caused by e.g. a dent or debris whereby an anomaly can be missed such a location shall be carefully checked).  Other lists: If requested by the client a list with specific, to be indicated, items. On the Client’s request also the location of the deepest point in the metal loss area or clustered area shall be reported. Unidentified/unknown features with strong signal shall be reported as “unknown” with, in commentary, an indication of the signal level. The list of anomalies shall be compatible with standard files such as CSV, ODS or another agreed format. 7.3.3 List of components The list of components shall be a listing of all feature types as listed in Appendix 3, except welds and anomalies. The list of components shall contain the same fields as the pipe tally. The list of components shall be compatible with standard files such as CSV, ODS or another agreed format. 7.3.4 Summary and statistical data The summary and statistical information as stated below should be agreed between Client and Contractor. 7.3.4.1 Metal loss If a metal loss tool was run, the summary report for metal loss shall contain a listing of:  Total number of anomalies  Number of internal anomalies  Number of external anomalies  Number of anomalies for each metal loss anomaly class  Number of anomalies per depth range of 10% (lower limit included)  If applicable, number of anomalies per ERF range of 0.1, starting from 0.6 (lower limit included). The following plots shall be provided:  If applicable, sentenced plot including ERF=1 curve of anomaly length against metal-loss feature depth showing all anomalies for each representative wall thickness  Orientation plot of all anomalies over the full pipeline length  Orientation plot of all internal anomalies over the full pipeline length  Orientation plot of all external anomalies over the full pipeline length  Orientation plot of all anomalies as function of relative distance to the closest girth weld. Pipeline Operators Forum – www.pipelineoperators.org - 31 -  Specifications and requirements for in-line inspection of pipelines - Version 2016 7.3.4.2 Cracks, crack-like and crack colonies If a crack detection tool was run, the summary report for cracks, crack-like and crack colonies shall contain a listing of:  Total number of anomalies per type and orientation to pipe axis  Number of internal anomalies per type and orientation to pipe axis  Number of external anomalies per type and orientation to pipe axis  Number of anomalies per type per depth range of 2 mm and orientation to pipe axis (lower limit included). The following plots shall be provided:  Number of anomalies over the pipeline length  Circumferentially orientated anomalies as function of relative distance to the closest girth weld  Longitudinally orientated anomalies as a function of relative distance to the seam weld over the pipeline length. 7.3.4.3 Local and global geometry features If a geometry tool was run, the summary report of geometry tool shall contain a listing of:  Total number of dents, ripples/wrinkles, buckles  Total number of ovalities  Total number of joints with ovality  Total number of other localized deformation/geometry anomalies  Number of dents, ripples/wrinkles, buckles per depth range of 1%  Number of ovalities per ratio range of 1%  Number of joints with ovality per ratio range of 1%  Orientation plot of all dents, ripples/wrinkles, buckles over the pipeline length  Orientation plot of all ovalities over the pipeline length. 7.3.4.4 Other types of features (e.g. illegal taps) If a tool capable of detecting other feature types was run, on request of the Client, the summary report for these features shall contain a listing of:  Total number of features per type  Number of internal features per type  Number of external features per type  Number of features per type per depth range of 10% (lower limit included). The following plots shall be provided:  Number of features over the pipeline length  Orientation plot of all anomalies as function of relative distance to the closest girth weld  Relative distance plot of all anomalies to the seam weld over the pipeline length. The lists and plots as defined above can be completed at Client’s request. Pipeline Operators Forum – www.pipelineoperators.org - 32 -  Specifications and requirements for in-line inspection of pipelines - Version 2016 7.3.5 Performance The final report shall contain:  Completed tables A3-1 to A3-8 as per the Contract  Completed tables A3-1 to A3-8 with actual run performance data depending on run conditions, tool functioning, pipeline cleanliness, etc. Actual performance data must be given for each pipeline section where it is constant. These sections will be clearly identified. 7.3.6 Dig sheet The purpose of the dig sheet is to provide the Client with all the information useful to carry out the field verification of a chosen feature. Unless agreed otherwise, dig sheets shall be included in the final report. Dig sheets shall contain the following information:  Length of pipe joint and (when present) orientation of longitudinal or spiral seam at start and end of every joint  Length and longitudinal or spiral seam orientation of the 3 upstream and 3 downstream neighbouring pipe joints  Log distance of anomaly  Wall thickness of the pipe joints (up to the 3 upstream and 3 downstream joints)  Log distance of closest features like magnet markers, fixtures, steel casings, tees, valves, etc.  Distance of upstream girth weld to nearest, second and third upstream marker  Distance of upstream girth weld to nearest, second and third downstream marker  Distance of anomaly to upstream girth weld  Distance of anomaly to downstream girth weld  Orientation of anomaly  Geographical coordinates of an anomaly if a mapping unit was applied, including the Geodetic Datum Standard used. Unless specified otherwise, WGS84 shall be used  Anomaly description and dimensions  Internal/external/mid-wall indication. 7.3.7 Software and signal In addition to the hard copy (if applicable), a user friendly software package shall be provided to enable review and assessment of the data collected by the inspection tool. This software shall enable the Client to carry out the following tasks:  Viewing of signal for each tool which was run, with possibility to modify gain, scale, etc.  Preparing dig sheet for each anomaly (including dents, combined features, etc.)  Plotting graphs and histograms  Computing ERF (input data, models)  Accessing detailed profile data for dents. Pipeline Operators Forum – www.pipelineoperators.org - 33 -  Specifications and requirements for in-line inspection of pipelines - Version 2016 7.3.8 Anomaly ranking method for ERF If requested by the Client, the Estimated Repair Factor for anomalies shall be reported on the basis of the assessment method indicated in Chapter 2.6.2 and input data shall be clearly stated in the final report. ERF shall be reported for each individual feature. When clustering is applied, specific ERF for clusters shall be provided by the Contractor. 7.3.9 Detection of markers AGMs or permanent markers that have been positively identified during the ILI run shall be indicated in the pipe tally. In addition, in the final inspection report the total number of installed AGMs and the number of identified AGMs shall be reported. 7.3.10 Personnel qualification An overview of key personnel qualification level that has been deployed for the ILI tool run, data analysis, reporting and final report review shall be reported. 7.4 Raw data report On request of the Client the raw data or processed raw data from an ILI run or a specific pipeline section shall be provided. The format of the data depends on the type of tool applied and is to be agreed between Client and Contractor and shall be defined in the inspection contract. 7.5 Multiple run comparisons report If requested by the Client, anomaly data from two or more successive ILI runs carried out on the same pipeline, shall be compared individually and clustered. Aim is to detect discrepancies between reported anomalies of successive runs like new or missed features, corrosion growth, etc. The run comparison report shall contain a table with matching and non-matching features per joint and include the results of these matching in terms of location, sizing and evolution. For a typical example see Appendix 9. If the same Contractor is chosen for two successive inspection runs, the Client may request:  A signal to signal comparison analysis between the two inspections  A 2nd report based on the raw data of the previous inspection, but processed with the new algorithm. The final run comparison report shall include the "Final report" (section 7.3) requirements and in addition:  A comparison in terms of quality, velocity, performance and accuracy (tool rotation, velocity, acceleration, behaviour anomalies, magnetization level, …)  A comparison of used tools (performance, characteristics, number, type and distance between sensors, acquisition frequency, environment, magnetization, …)  A comparison of analysis and reporting parameters (e.g. but not limited to algorithms, thresholds, assessment code, interacting rules, …) Pipeline Operators Forum – www.pipelineoperators.org - 34 -  Specifications and requirements for in-line inspection of pipelines - Version 2016 7.6 Experience report The experience report summarizes the operation. Good practices as well as possible improvements are reported. Special attention is paid to  Project planning  Interaction between interfaces  Logistics on site  Coordination with other operations  Data quality  Dig up results The report will contribute to improved future operations. 7.7 Additional reporting On request of the client an additional report might be requested including separate reports for each technology used in combination runs, Integrity assessment reports, etc. Pipeline Operators Forum – www.pipelineoperators.org - 35 -  Specifications and requirements for in-line inspection of pipelines - Version 2016 8 References 1. Anon, “In-Line Inspection Systems Qualification”, API 1163, American Petroleum Institute, 2nd Ed., April 2013. 2. Cosham, A. and Hopkin, P., “Pipeline Defect Assessment Manual (PDAM)”, A Joint Industry Project, Penspen, 2013. 3. Anon, “Recommended Practices For Managing Near-Neutral Ph Stress Corrosion Cracking” 3rd Ed., Canadian Energy Pipeline Association (CEPA), May 2015. 4. Anon, “In-line Inspection Personnel Qualification and Certification” ANSI/ASNT-ILI-PQ-2005, American Society for Nondestructive Testing. 2010. 5. Anon, “Guidance on Achieving ILI First Run Success”, Pipeline Operators Forum, December 2012. 6. Anon, “In-line Inspection Check Lists”, Pipeline Operators Forum, December 2012. 7. Anon, “ILI Pipeline Questionnaire”, Pipeline Operators Forum, December 2012. 8. Kastner, W., Rohrich, E., Schmitt, W. and Steinbuch, R., “Critical Crack Sizes in Ductile Piping”, Int. J. Press. Ves. Piping 9 (3) 197–219, 1981. 9. Anon, “Fitness-For-Service”, API 579-1/ASME FFS-1, American Petroleum Institute, 2016. 10. Anon, “Guide to Methods for Assessing the Acceptability of Flaws in Metallic Structures”, BS 7910, British Standards Institution, 2013. 11. Anon, “Manual for Determining the Remaining Strength of Corroded Pipelines”, ASME B31G, American Society for Mechanical Engineers, 2012. 12. Anon, “Corroded Pipelines”, DNV-RP-F101, Det Norske Veritas, January 2015. Pipeline Operators Forum – www.pipelineoperators.org - 36 -  Specifications and requirements for in-line inspection of pipelines - Version 2016 Appendix 1: ILI companies that provided comments to the draft version of these specifications COMPANY COUNTRY WEBSITE 3P Services Germany www.3p-services.com A. Hak Industrial Services Netherlands www.a-hak-is.com Baker Hughes USA www.bakerhughes.com General Electric (PII) USA www.geoilandgas.com/pii NDT Global Ireland http://www.ndt-global.com Pipe Survey International Netherlands www.pipesurveyinternational.com PipeWay Brazil www.pipeway.com Rosen Switzerland www.rosen-group.com T.D. Williamson USA www.tdwilliamson.com Quest Integrity USA www.questintegrity.com Pipeline Operators Forum – www.pipelineoperators.org - 37 -  Specifications and requirements for in-line inspection of pipelines - Version 2016 Appendix 2: Guideline to clients for defining specific details of the POF specifications Introduction The POF document “Specifications and requirements for in-line inspection of pipelines” gives an outline of advised specifications for In-line-inspection (ILI) of pipelines. The Client should adapt certain specifications to reflect Client’s specific requirements. For certain aspects of the inspection and/or reporting requirements, some options and default values are already considered, but the document gives the opportunity to define specific items. This guideline is intended to support the Client by listing the considered optional items in the specifications based on the expected integrity threats of the pipeline to be inspected. The items should be defined prior to sending the specifications to the ILI company and agreement of the contract. In addition, in this guideline also some notes and advised specifications are given (printed in Italic), like the minimum requirements that are regarded essential for a successful ILI run. Chapter 2.4.2 - Dent The Client should agree with Contractor the methodology if strain based assessment is required and of minimum planar size accuracies of dents expected to be reported for technology selection. Chapter 2.4.4 - Ovality Default reporting is the maximum ovality measured. If another value shall be reported, this is to be indicated. Chapter 2.4.6 - Ripple/Wrinkle Maximum values shall be reported. If additionally also the maximum strain should be reported, the methodology shall be agreed between Client and Contractor. Chapter 2.6.1- Interaction rules ASME B31G methodology is specified as the default assessment method, but another methodology can be specified and agreed if required. Chapter 2.6.2- Indication of anomaly severity (ERF) The ASME B31G methodology is specified as the default assessment method for the ERF calculation, but another methodology can be specified if required. Chapter 2.7 Resolution of measurement parameters The Client shall specify if SI, metric or alternative units shall be used. Chapter 2.7 – Coordinates for mapping work. It is important for the client to specify the final coordinates required from the mapping data. Considerations will include using the latest geodetic system to ensure ‘future proofing’ of data, but also to ensure the data will match any existing mapping system used (which may in fact not be the latest system). Chapter 0 - Health and Safety Health and safety requirements to be agreed between Client and Contractor, including Client' policy on ATEX, IECEx or equivalent directive. Pipeline Operators Forum – www.pipelineoperators.org - 38 -  Specifications and requirements for in-line inspection of pipelines - Version 2016 Chapter 3.1 – ATEX Client shall specify if ATEX certification is required and if so, assess the zone classification. Client shall specify, whether the Contractor shall ensure safe operation of ILI equipment under explosive conditions for pressures >.11 MPa during receiving and launching of tools. Chapter 4.3 Client may request for information on tool readiness. Chapter 4.4.1 - General Client may request to complete the alternative table A5-3a in favour of tables A5-2 and A5-3. If a higher level of performance is based on more detailed analysis, the additional performance level and commercial basis shall be agreed. Chapter 4.4.4 Access to supporting performance information If access on information in support of stated tool performance specification is requested, details on how and where shall to be agreed. Chapter 4.6 - Changes to tool specification or performance specification sheets Any requirement for reassessment of features as a result of tool specification changes shall be agreed (if required). Chapter 0 - Personnel qualification Default requirements for qualifications of key personnel are given but can be specified otherwise by the Client. Chapter 6.2 - Contracting Various contracting details should be specified. Chapter 0 - Reporting Two reports are indicated as standard (default). Additional reporting should be requested and agreed. Chapter 7.1 - Operations report Default time for reporting is within 2 days. Change of reporting time should be agreed. Default content report is listed, modifications to be agreed. Default values for acceptable data loss are given, modifications to be agreed. Chapter 7.2 - Preliminary report Default time for reporting is within 4 weeks. Change of reporting time should be agreed. Default content report is listed, modifications to be agreed. Typical reporting criteria are given, modifications to be agreed. Chapter 7.3 - Final report Default time for reporting is within 8 weeks. Change of reporting time should be agreed. Default content report is listed, modifications to be agreed. Default reporting thresholds are listed, modifications to be agreed. In chapter 7.3.1 to 7.3.10 typical reporting options are listed and should be used as default. Modifications to be agreed. Chapter 7.4 - RAW data report If requested by Client, the raw data or processed raw data shall be provided by agreement. Pipeline Operators Forum – www.pipelineoperators.org - 39 -  Specifications and requirements for in-line inspection of pipelines - Version 2016 Chapter 7.5- Multiple run comparisons report If requested by Client, anomaly data from two or more runs shall be compared. A typical reporting structure is given, modifications to be agreed. Chapter 7.6- Additional reporting Any additional desired reporting should be requested and agreed upon by Client and Contractor. Appendix 5 - Tool technology performance specifications It is requested that the ILI company provides information on anomaly detection and sizing and other measurement capabilities of their tool. Below some typical values that can support the Client in his review of the proposed specifications. POD of detected anomalies The POD of a tool is normally taken at 90% and is based on anomalies with reference dimensions as given in the tables of appendix 5. The typical minimal detectable depth of a high resolution MFL tool for general corrosion is 10% t and for pitting defects it is 15% t both with a POD of 90%. For seamless pipes and other category defects other values can apply. The typical minimal detectable defect depth of a UT tool is 1 to 1.5 mm with a POD of 90%. Depth, length and width sizing accuracies The accuracy depends on the anomaly dimension class: Typical for (high resolution) MFL tools: depth 10-15% t, length and width accuracy 10-20 mm Typical for UT tools: depth 0.3 – 0.5 mm, length and width accuracy 10 mm For anomaly depth, length and width sizing accuracy, the typical certainty level is 80%. Accuracy of distance and orientation (clock position) of features: Typical accuracy of distance to/from marker: 0.25% of distance Typical accuracy of distance to closest weld: 0.15 m Typical accuracy of circumferential position: 10°. Certainty and accuracy of sizing deformations by geometry tool: The certainties and accuracies of reported dents and ovalities shall be defined. Typical certainties and accuracies are: Ovalities: ID reduction, accuracy 1% of pipeline ID with certainty = 90% Length, accuracy 10% of pipeline ID with certainty = 90%. Dents: Depth, accuracy 1% of pipeline ID with certainty = 90% Length, accuracy 10% pipeline ID with certainty = 90% Width, accuracy 10% pipeline ID with certainty = 90%. Mapping: The accuracy of mapping is dependent on a variety of factors. Some of the main ones include the quality/technology of the IMU, the accelerometers, the odometer, the AGM’s clock matching that of the inspection tool, the AGM’s and also spacing of the accuracy with which the position of AGM is determined. Manufacturers and service providers will have varying technologies that provide varying accuracies. It is generally thought that the accuracy of an IMU varies over distance travel, but the accuracy degrades over time, so it is important to consider the speed of the product in the pipe during the mapping inspection run. It is therefore important to specify maximum and minimum flow rates during mapping surveys. Pipeline Operators Forum – www.pipelineoperators.org - 40 -  Specifications and requirements for in-line inspection of pipelines - Version 2016 AGM’s are used to correct the IMU’s ‘drift’ over time (and hence distance). The closer the AGM spacing, the more accurate the final coordinates will be. Many mapping runs use a 1 mile or 2 kilometre spacing, but for very or extremely high accuracy work 1 kilometre or even 500m spacing can be used. AGM’s should not be placed where the pipe is too deep for the inspection tool to be detected by the AGM. Below are some reference documents that relate to magnetic properties for MFL inspection: - In “Magnetisation as a key parameter of magnetic flux leakage pigs for pipeline inspection” by H.J.M. Jansen, P.B.J. van de Camp and M. Geerdink (Insight Vol. 36, September 1994) it is concluded that MFL pigs are least sensitive to error sources (e.g. residual stresses, pressure, remnant magnetization) if the magnetic induction in the pipe wall > 1.8T. The magnetic field strength required to obtain such an induced magnetisation level depends on the type of material, wall thickness, pig speed etc. - NACE International Publication 35100: “In-Line Non-destructive Inspection of Pipelines gives the following typical specifications for high-resolution MFL tools: Minimum magnetic field strength: 10 to 12 kA/m (3 to 3.7 kA/ft) Minimum magnetic flux density: 1.7 T. Mapping tool specifications Geographical locations shall be reported in GPS coordinates by default, but another method can b