FOR OPEN RELEASE
Issue 1: 26 September 2016
HOIS Joint Industry Project:
Good practice for NDT in the oil & gas industry
Highlights for 2015/16
Membership
The total number of HOIS members was 43 as of April 2015. Membership comprised fifteen category 1 members (oil
& gas producing companies) and twenty eight category 2 members (inspection service companies, inspection
equipment suppliers and notified/appointed bodies). The UK Health and Safety Executive is also a member.
Category 1 members
Category 2 members
BG Group
Shell
Aker Solutions
GE Inspection
Technologies
Olympus NDT
BP
Statoil
Applus RTD
GUL
Rosen Group
ConocoPhillips
Talisman
Baugh & Weedon
HSE
SGS
DOW
Taqa
Bilfinger
HSI Lateral Wave
Sonomatic
Gasco
Total
Bureau Veritas
Innospection
Gassco
CAN
Inspectahire
Marathon Oil
DNV GL
ISQ
TRAC Oil and Gas
Nexen Petroleum
U.K. Ltd
Doosan
Lloyds Register
TSC Inspection
Systems
Petrobras
Eddyfi
Mistras Group
Santos
FujiFilm
Oceaneering
International
Sonovation TUV
Rheinland
Stork Technical
Services
Total subscription income in the year 2015/16 was £836,000 which gave substantial gearing for each member’s
subscription (£33,000 for oil & gas company members, £11,000 for inspection service/vendor company members
and HSE).
SPECIMEN TRIAL AND STORAGE (‘NICE’) FACILITY
The HOIS trial and specimen storage facility (referred to as the ‘National Inventory of Corroded Equipment’ or NICE)
continues to play an important role by providing trial facilities for a number of HOIS projects.
The facility houses a large number of ex-service components with examples of weld corrosion, flange face corrosion,
external corrosion scabs, and corrosion under pipe supports (CUPS), supplied by several of the category 1 HOIS
members. A recent addition is an “L-pipe”: a 7m straight 8" sch 40 carbon steel pipe length with a 90° bend and
further 2m straight.
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Several rigorously controlled blind trials of inspection techniques have been performed on these specimens by HOIS
category 2 members, hosted by ESR Technology, primarily for the HOIS projects on inspection of external corrosion,
corrosion under insulation (CUI), pipe supports (CUPS) and a guided wave corrosion monitoring trial on the L-pipe.
The NICE facility provides HOIS with substantial capabilities for storage of ex-service components, some of
significant size. The venue continues to prove its worth in allowing a number of blind inspection trials to be carried
out for technique assessment, verification and validation. It has also been agreed that members may also commission
ESR to host technique validation and inspector competence verification trials outside of HOIS, using this facility.
Technical Programme
1. Evaluation of CUI inspection methods
Main highlights: Issuing a HOIS report containing results of the substantial trial programme involving both
onshore UK site trials and those at the HOIS NICE facility. A draft guidelines document for NDT of CUI has
also been issued to HOIS members for comment.
Corrosion Under Insulation (CUI) is an unpredictable
corrosion mechanism that can occur anywhere in the
large amounts of insulated components found on
many oil and gas assets. It is known to be a
challenging form of degradation to detect reliably
using NDT methods.
Ideally NDT techniques would reliably and cost
effectively detect the presence of and accurately size
CUI across a wide variety of components and
geometries. However, effective rapid screening to
identify suspect areas for further investigation is also
of substantial value. Current experience with and track
record of NDT techniques is mixed, and the perception
of some is that the industry awaits more effective NDT
approaches. Given these issues, many upstream
asset owners rely on stripping followed by visual
inspection.
Examples of CUI
This ambitious HOIS project included a substantial experimental trial programme with both on-site and laboratory
based trials which have demonstrated the potential of novel techniques in addition to highlighting some limitations of
existing technologies.
2. Evaluation of techniques for inspection of corrosion under pipe supports (CUPS)
Main highlight: Issuing of a HOIS report on the results of further NDT trials for corrosion under pipe supports.
These independently verified HOIS trials, based on carefully obtained benchmarking information, have
allowed a detailed assessment of the current capabilities of a large number of CUPS NDT techniques. This
has led to the development of a draft guidance document which has been issued to members for comment.
In service corrosion under pipe supports (CUPS) is an
area of active concern in the oil and gas industry
because of the number of leaks and ruptures that have
occurred in service. The main aim of this project has
been to evaluate the performance of available NDT
techniques by means of experimental blind trials. The
focus has been on the assessment of through wall
sizing accuracy of the technique, although detection
performance was also evaluated.
Examples of CUPS
These independently verified HOIS trials, based on
carefully obtained benchmarking information, have allowed a detailed assessment of the current capabilities of a
large number of techniques. The results of the trial programme have led to the development of a draft guidance
document on inspection of corrosion under pipe supports, which has now been issued to members for comments.
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3. NII & IVI trials on ex-service pressure vessels
Main highlights: The results of an ambitious and extensive HOIS
project involving both NII and IVI trials on two ex-service pressure
vessels with differing forms of service degradation have been
published in a trial report. The project has provided a unique set of
results which have been compared with detailed benchmark data.
Crack like indications found by
internal dye penetrant examination
Two ex-service pressure vessels with differing forms of degradation are
installed at the ESR head office near Warrington. One has extensive
corrosion over the lower half of the vessel whereas the other has stress
corrosion cracking (SCC) and shallow pits in the internal CRA cladding
layer.
These vessels have provided a unique opportunity for internal visual
inspection (IVI) and non-intrusive inspection (NII) trials to be followed by
detailed comparisons with benchmark data. The trial programme
consisted of five IVI and external NII trials.
One of the aims of this project was to evaluate the effectiveness and
performance of NII and IVI techniques; this has implications for the
application of DNV-RP-G103 (which gives guidance on when NII can be
justified as an alternative to the more traditional IVI approach and aims to
ensure that, when NII is performed, it is at least as effective as IVI).
Manway entrance of pressure vessel.
4. Development of Interactive knowledge bases (IKBs) for subsea inspection
Main highlight: Release to members of the new HOIS
subsea interactive knowledge base (IKB) and
associated modules on composites, FPSOs and
flexible risers.
Home page of new Subsea IKB
HOIS has completed programmes to collate information on
subsea commercial equipment available for diverless
inspection and monitoring in the splash-zone, shallow
water and deepwater. These programmes generated a
substantive amount of structured information on
underwater inspection equipment, deployment systems,
access and communication methods. This information has
been collated into a new subsea inspection IKB (accessed
via a simple web-based browse facility) with additional
sections on FPSOs, flexible risers and composites.
5. Development of Guidance for Effective Inspection of Pipework
Main highlight: Circulation of a preliminary draft of a guidance
document on more effective routine inspection of pipework for internal
degradation.
The industry currently expends considerable resources on routine manual
pulse-echo inspection of piping for internal corrosion. The effectiveness of
these extensive inspection programmes is affected by the limitations of the
approach in terms of accuracy, probability of detection, coverage and the
locations selected for inspection.
The main objective of this project is to develop guidance on more effective
inspection of pipework in situations where degradation resulting in internal
wall loss, e.g. corrosion and erosion, is identified as a potential threat to
integrity. The document will provide practical guidance on how to implement
and manage improvements to current practice so that operators can use it to
make changes to their existing approaches to make assurance of pipework
integrity more efficient and cost effective.
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Input Information defines
Predicted Current State
Review all background
information
Aim of
Inspection
Clarify desired output
requirements
Plan
Develop workscopes to
meet desired outcomes
Enact
Inspection
Acquire information on
current state of
pipework
Understanding of
Current State
Analyse inspection
results wrt current state
and short term actions
Prediction of Future
State
Analyse results to
predict future state and
longer term actions
High level flow chart for inspection
6. Qualification of ultrasonic corrosion monitoring systems by means of accelerated
corrosion trials
Main highlights: Issue of a comprehensive report on the HOIS accelerated corrosion trials of periodic
inspection systems on flat plates. Initiation of first round of periodic inspection trials on corroded pipes.
The first independently verified trials of a long range guided wave continuous monitoring device installed
on a 9m test piece, including a 90° bend.
Knowledge of the corrosion rate in plant and facilities is of increasing interest to operators in order to enable active
management of corroding systems and to optimise inspection programmes. Periodic ultrasonic measurements, either
at points or by scanning areas, is being increasingly used for this application. Recent HOIS projects have shown
that the accuracies achieved using different systems can be variable. An increasing number of continuous monitoring
systems using installed (fixed) sensors are entering the market, with very different properties.
This project has included the performance accelerated corrosion trials on flat plates in order to further develop the
HOIS Recommended Practice on monitoring of corrosion by means of periodic inspection ultrasonic inspections.
Subsequent work looks at test pipes (rather than flat plates) and the first independently verified trials of a long range
guided wave gPIMS system to assess detection performance on straight pipe sections and around a pipe bend.
L-pipe with trace heating applied and no insulating jacket.
Installation of gPIMS ring.
The third and final phase of this project will be modifications to the existing HOIS RP precision thickness
measurements for ultrasonic corrosion monitoring, based on the results from the periodic inspection trials.
7. External Corrosion Inspection – Phase 2 project
Main highlight: This new HOIS project aims to perform further trials of the most promising techniques
identified in the earlier project C12-01 and to deliver an RP and generic inspection procedures which will
lead to a more consistent approach across the industry. Ultimately this will result in greater operator
confidence that there will not be a loss of containment due to external corrosion.
A substantial 3 year trial based project (C12-01) on external corrosion inspection
was completed in 2015 and has led to a second phase of work which aims to
evaluate in more detail the most promising techniques identified in the first project
by performing trials on further examples of corrosion scabs. Any novel or
emerging technologies with relevance to this application will also be trialled.
Recent progress includes further M-skip trials on thicker-walled components
which have produced the most accurate results obtained by any recent HOIS trial
on inaccessible components. Emerging or novel technologies currently being
investigated include the Eddyfi LYFT PEC system, a low frequency eddy current
technique and Echo3D.
Externally corroded component
The final objective is to deliver an RP and generic inspection procedures for
inspection of external corrosion. This will provide operators with technique capabilities and limitations, allow
inspection service providers to improve their procedures and lead to a more consistent approach across the industry.
Ultimately this will result in greater operator confidence that there will not be a loss of containment due to external
corrosion.
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8. Non-intrusive inspection of CRA clad Vessels
Main highlight: Completion of the Phase 1 project report
Non-intrusive inspection (NII) of corrosion resistant alloy
(CRA) clad vessels poses particular inspection challenges
due to the differing types of cladding in use, and their
degradation mechanisms which frequently include small
pitting and fine stress corrosion cracking (SCC), both of
which can be difficult to detect and characterise non
intrusively.
The first phase of this project assessed operators’ views on
the integrity risks associated with CRA lined equipment
and how degradation in CRA lined vessels is managed.
Ex-service CRA clad vessel installed at ESR Warrington
The project now focuses on performing evaluation trials of techniques for the NII of the internal cladding condition as
well as the carbon steel vessel shell. The blind trial components include the ex-service CRA clad vessel (currently
installed at ESR Warrington) and two additional test specimens: a manufactured weld overlay plate sample and an
ex-service heat exchanger plate with hot rolled cladding (similar to the open specimen
9. Guidelines for External Remote Visual inspection (RVI)
Main highlight: Release of phase 1 report which included a summary of visual
inspection standards, RVI equipment, the results from initial scoping
experiments on RVI image resolution and initial suggestions for guidance on
RVI image quality.
Remote visual inspection (RVI) equipment including UAVs and static digital cameras
are increasingly being used in the industry to obtain information to inform engineering
assessments on external condition of piping, vessels, tanks and structures. However,
there is a lack of any guidance concerning the performance of the RVI system as a
whole, with no definition of the minimum image qualities needed to make adequate
engineering assessments.
HOIS has produced a report which contains a summary of visual inspection standards,
information on currently available RVI equipment, HOIS member experience and
quantitative measures of image quality.
UAV RVI image of a
flare stack
This valuable work will be continued in a new project for the HOIS 2016/17 year which
aims to develop an authoritative trial based guidance document on the usage of UAV
(drone) based external RVI. The main focus will be on the minimum quality of the images generated with particular
emphasis on 2-3 of the most frequent UAV inspection applications within the industry such as flare stacks or coating
assessments. The definition of minimum quality standards for images will inform decisions about the selection of
appropriate RVI equipment and lead to more reliable engineering assessments.
10. Human Factors Aspects of NDT in the Offshore Oil & Gas Industry
Main highlights: Raising awareness of human factors within HOIS and their effects on inspection. The phase
1 report, published in May 2015, summarises lessons learned from other industries and past human factors
studies for NDT inspection before identifying the key human factors for
successful inspections.
Human factors affect all stages of the inspection process and are influenced by
environmental factors such as ergonomics, temperature and shift time as well
as the ethos of the companies This project has raised general awareness and
discussion of human factors for the first time in HOIS.
There is currently little guidance of the human factors affecting the different
stages of an offshore inspection workscope and how to minimise their effects.
Phase 2 of the work begins in April 2016 and aims to address this gap by
producing specific guidance for three selected NDE methods: internal visual
inspection of pressure vessels, and external visual inspection and manual UT
inspection of pipework for corrosion.
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Other projects:
In addition to the above highlighted activities, other HOIS projects in 2015/16 comprised:
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Inspection of buried pipes at road crossings and under dykes - reviewed potential techniques for the
inspection of pipes at road crossings and dykes with relevant case studies.
Subsea coating inspection trials - three underwater inspection trials on coated test pieces with simulated
realistic corrosion defects.
HOIS Interactive Knowledge Base (IKB) on NDT (M6) – Continued updating of information and maintenance.
FPSO, flexible risers and subsea working group (M9) – Annual meeting held March 2016.
Member Benefits
Members gain access to, and have rights to exploit, the results arising from an annual programme of work, currently
with a value of over £650,000. This allows cost-effective development of, and early access to, relevant new
technology and optimised performance of NDT techniques. The main aim is to achieve more reliable and cost
effective NDT, and hence improved operational safety.
Members have identified the following key benefits from participation in HOIS:
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The regular HOIS meetings provide a forum in which oil & gas plant operators and service companies meet and
exchange ideas and views on NDT needs and developments. This caters for upstream applications primarily,
but with some downstream interest as well.
HOIS is a good vehicle to address technology gaps that need medium term technical development, for which
individual member companies cannot justify "going it alone".
With the participation in "evaluation projects", and maintenance of the IKB, HOIS generates and disseminates
the knowledge required to operate techniques in an effective and responsible manner (including evaluating the
performance of the more mature techniques compared to the latest technology).
HOIS is recognised as an industry leader in identifying future requirements in both the service sector and
research arena. This is of particular interest to many of the larger inspection service providers, who are also able
to licence any technological developments arising from projects.
HOIS is recognised by regulatory bodies as a group that helps to develop best practice and improvements in
integrity monitoring of oil and gas plant/equipment.
HOIS members may commission ESR to host technique validation and inspector competence trials outside of
HOIS, using the well benchmarked specimens within the NICE facility and the ex-service pressure vessels at
ESR Warrington.
World-wide access to the Internet-based Interactive Knowledge Base (IKB) on NDT.
Access to the HOIS members only website, which contains all information (reports, presentations etc.) generated
since the start of the present HOIS Agreement, in April 1999.
Further Information
HOIS has a publicly accessible website at: www.hois.co.uk. Further information on HOIS can also be obtained from
the HOIS project manager:
Dr Steve Burch, ESR Technology Ltd steve.burch@esrtechnology.com
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Members’ logos for 2015/16
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