2017 Award Nomination - NACE Internationalevents.nace.org/WA/mp/FiGS-Field-Gradient-Sensor.pdf · 4...
Transcript of 2017 Award Nomination - NACE Internationalevents.nace.org/WA/mp/FiGS-Field-Gradient-Sensor.pdf · 4...
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2017 Award Nomination Title of Innovation: FiGS - Field Gradient Sensor
Nominee(s) Jens Christofer Werenskiold and John Robert Vinje of FORCE Technology Norway AS]) Category: Cathodic Protection
Dates of Innovation Development: (from [1, 2012 ] to [10, 2016] and in continuous development)
Web site: www.figs.no
Summary Description: FORCE Technology Field Gradient Sensor
(FiGS) is a state of the art, non-contact CP
inspection tool that performs highly
accurate measurements of electric currents
in seawater, with a resolution and detection
level that surpasses all other sensors
available on the market. The sensitivity
enables the identification of corrosion
problems and the characterization of CP
system status on pipelines and subsea
structures, even when buried.
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Accurate field gradient data from FiGS combined with FORCE Technology’s proprietary CP Computer
Modelling expertise will not only give our clients confirmation of a protected structure. Design codes are
usually overly conservative when calculating the steel current density, and using real values in retrofit
CP designs have demonstrated typical cost savings of 50%
Surveys with FiGS are carried out with Remotely Operated Vehicles (ROV) as the price of oil is dropping,
the push for cost-saving subsea operations is at an all- time high. Subsea vehicles are now moving
towards automation with longer, faster subsea surveys, avoiding the heavy vessels and equipment
required for ROV operations. FiGS is the only CP tool on the market today that offers non-contact CP
inspection suitable for autonomous vehicles.
The FiGS technology has proven substantial cost savings on several levels, from more efficient and
quicker inspections, to eliminating the use of divers and excavation of buried or covered structures. The
high quality mapping of field gradient data offered by FiGS has opened possibilities, not only to predict
the future performance and degradation of a CP system, thereby reducing the frequency of inspections,
but also to pinpoint areas of interest offering only necessary and coordinated intervention. Due to the
added value and cost saving potential, several customers have now established FiGS as their preferred
CP Inspection tool, for everything from baseline to standard periodic and life extension surveys.
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Full Description:
(Please provide complete answers to the questions below. Graphs, charts, and photos can be
inserted to support the answers.)
1. What is the innovation?
FiGS (Field Gradient Sensor) is a state of the art, non-contact CP inspection tool that performs highly
accurate measurements of electric currents in seawater, with a resolution and detection level that
surpasses all other sensors available on the market. The sensitivity of the sensor enables the
identification of corrosion problems and the characterization of CP system status on pipelines and
subsea structures, even when buried.
2. How does the innovation work?
The sensor has two sensing electrodes, rotating around a common axis, measuring the relative field
gradient in the seawater. A huge advantage of this device is that it can measure far weaker signals than
existing sensors, and it will also measure the vector of the signal. The compact size of the sensor enables
electric field measurements close to the surface, where the field is stronger, thereby increasing the
accuracy. The short inter-distance between the electrodes gives measurements close to a point
measurement, which closely approximates the real field gradient, as opposed to averaging the gradient
over a greater distance.
In addition to increasing the accuracy, this also increases the quality and reliability of the readings. Due
to the physical shift between the two reference cells, the system will not be influenced by cell drift and
filtration of noise fields from the ROV will be a lot easier.
Operation
FiGS is normally fitted to a ROV, but the non-contact method also opens up the possibility for use on
Autonomous vehicles (AUV/AIV). FiGS inspections are performed as stand-alone inspections but also
often tagged on to general visual inspection (GVI) programs.
Sensitivity
The measurement range is from 0.1 μV/cm to 10 mV/cm. The accuracy of the measurements of the
electric field gradient vector is 2° and absolute value accuracy of 1% of the reading.
The sensitivity surpasses all other sensors on the market. Where the traditional sensors are unable to
distinguish anodes and coating damages from noise, FiGS’ high signal to noise ratio gives detailed
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information, even at low current outputs.
The figures above show the sensitivity of FiGS compared to traditional sensors.
Angular sensitivity
The angular information is used to map where the current is distributed from and where it is delivered.
This feature opens up for better interpretation and understanding of how different CP systems interact
with each other, and how current is drained to connected structures or buried/piled areas. The high
angular sensitivity also comes to its right when inspecting multiple pipelines installed in the same
trench, making it possible to separate the lines from each other and associate the correct anodes to the
correct line. As an added bonus, using the angular output on buried pipelines, we are able to triangulate
the location of anodes, giving us depth of burial and location. This feature has been used to update
correct pipelay, where traditional pipetrackers have not been able to locate the pipe.
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The figure above shows how FiGS angular information can be used to triangulate anodes to give depth
of burial and location.
Figure above shows 3D plot of field gradient measurements when passing two anodes
3. Describe the corrosion problem or technological gap that sparked the development of the
innovation? How does the innovation improve upon existing methods/technologies to
address this corrosion problem or provide a new solution to bridge the technology gap?
FiGS was initially developed, and partially funded by Statoil, Shell and Gassco, to make a tool
sensitive enough to detect small coating damages on a Statoil DEH (direct electrically heated)
pipelines. A small damage in the coating of a DEH pipeline can be devastating, as the AC
Seabed
Sensor positions
Pipe location
Field gradient vectors
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currents from the piggyback (AC) line can short circuit through the pipeline leading to
aggressive AC corrosion. The sensitivity obtained however later opened the door for much
wider use of the sensor, and today we use it for:
Mapping of Field Gradients (FG) on steel and anodes, forming the basis for:
o Measurement of Current Densities (CD) on steel and anodes, based on Field
Gradients above
o Anode current outputs, based on Current Densities above
o Estimation of remaining anode lives, based on current outputs above
o Detection of coating damages, with calculated size
o Potentials (within +/- 5 mV of contact measured potentials)
The measuring method is a non-contact method, and the sensitivity enables its use on buried
pipelines and structures, where contact measurements are not possible. In addition, this
enables measurements from a greater distance on exposed structures and pipelines. It also
makes it possible to determine the real steel current density. Proving the real steel current
density for use in retrofit designs has shown huge cost savings for our clients. The real steel
current densities are normally much lower (50%-70% lower) than in the design codes, often
reducing the retrofit needs by more than 50%.
Another benefit of the non-contact method is that it makes Cathodic Protection inspection
possible using autonomous vehicles. Using two sensors with 90 degree displacement, we are
able to measure currents in 3D (three dimensions) mapping the current flows in great detail.
This enables us to use our CP computer modelling tool SeaCorr™, to make potential plots of
complex subsea structures, such as X-mas trees, Manifolds, SSIV’s, wellheads etc…
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In the example above, we found current flowing into the structure and not out from the
structure as we expected. This indicated that the anodes were completely depleted and that all
the protection was offered by the connected pipelines. GVI confirmed the anodes on the
manifold to be depleted.
The potential in the above example was calibrated based on one stab point, since it was
available, but we can also use an anode measurement by FiGS as reference, using the open
circuit potential to calibrate the potential level. This method has proven an accuracy of
potential in the +/- 5mV range.
Buried pipelines and structures:
Before FiGS came on the market, buried or covered pipelines were often inspected only by
internal pigging, excavation or an expensive and HSE critical diving operation. An internal pig
can give you information on internal pitting, the wall thickness and such, but provides no
information about the status of the external CP.
The sensitivity of FiGS enables a much more cost and HSE efficient option. By simply flying over
the buried sections with FiGS, we are able to collect all relevant information about the status of
the external CP system; reporting potentials plots, anode current outputs, steel current density,
anode wastage, coating damage and even predict the life expectancy of the CP system. We
have several reference projects on buried pipelines and structures, where we have saved our
clients both time and money, at the same time eliminating the HSE risk involved with a diving
operation.
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4. Has the innovation been tested in the laboratory or in the field? If so, please describe any
tests or field demonstrations and the results that support the capability and feasibility of the
innovation.
FiGS has been commercially used since 2013 by many of the global, Oil and Gas companies
already. Some abstracts from the results so far follows: (innovasjonen virker ikke som en nyhet
slik det står her). Kanskje få inn «during the last year»?
5. How can the innovation be incorporated into existing corrosion prevention and control
activities and how does it benefit the industry/industries it serves (i.e., does it provide a cost
and/or time savings; improve an inspection, testing, or data collection process; help to
extend the service life of assets or corrosion-control systems, etc.)?
FiGS can easily be incorporated into existing CP inspection programs, and can replace
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traditional CP inspection tools. The big benefit of using FiGS is that it will give you all the
information normally obtained by two different (field gradient and potential) systems in one.
Normal contact measurements are time consuming, and impossible for buried pipelines and
structures. FiGS can gather data continuously as you pass over the given structure, also buried,
which will save both time and cost.
Another key feature is that by measuring the current, we are able to calculate the remaining life
of the anodes, leading to extending the life of an asset or at least optimize the retrofit. By
knowing the remaining life of the system you can also go from a periodic inspection program to
a predictive (risk based) inspection program, extending the intervals between surveys.
Some examples of the benefits for our clients are:
Eliminating diving scope on concrete mattress covered flange, saving the client GBP
250.000 and eliminating HSE risk
Reducing retrofit need of a buried concrete covered pipeline by 50%, using real current
density as opposed to design codes, saving the client approx. USD 15 Million. At the
same time correcting pipe position, as FiGS could track the pipe where an active pipe
tracker could not (too deeply buried)
Reducing retrofit need of an exposed bundle by 50%, using real current densities as
opposed to design codes, saving the client approx. USD 3 Million.
Detection of coating damage on flexible pipeline outer sheet and calculation of size of
the delaminated/seawater exposed armor.
Determination of potential profile along buried pipelines
Determination of current drain to wells
Determination of current distribution on offshore monopile structures, as well as
quantifying current drain to buried parts of the structure.
Detection of “non-working” anodes on jacket structure, where measured potentials
were good, calculating new life expectancy of the system
The list goes on and on. But the key feature is that we are able to get much more
information about the integrity of a CP system with FiGS than any other CP inspection
method available.
6. Is the innovation commercially available? If yes, how long has it been utilized? If not, what
is the next step in making the innovation commercially available? What are the challenges, if
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any, that may affect further development or use of this innovation and how could they be
overcome?
FiGS has been commercially available since 2013 with several projects under the belt,
worldwide. FiGS has been used on everything from exposed pipelines, buried pipelines, jackets,
manifolds, SSIV, X-mas trees, wind farm monopiles, flexibles, concrete mattress covered flanges
to wellheads and DEH pipelines.
FiGS is under continuous development, increasing post processing software efficiency,
upgrading hardware and continuously pushing the technology limits to keep up with customers’
requests for new features and areas for use (e.g pipetracking, tracking of powercables (AC/DC),
detection of damages on powercables(AC/DC), mapping of stray currents (AC) etc...). The
natural next step for FiGS is to integrate it into autonomous vehicles, and FORCE Technology is
working with several AUV operators to integrate the technology.
Some of the challenges are
FiGS weight (14 kg each). Can the AUV carry this much weight
Electrical interface between FiGS and ROV
Software to log and store FiGS data locally on AUV (start/stop sequence)
Possible interfering systems (electrical noise) on AUV
Mechanical interface (placement of sensors)
These are all challenges that are easy to resolve. It is just a matter of time and money.
7. Are there any patents related to this work? If yes, please provide the patent title, number,
and inventor.
Yes we currently have the following patent pending in Norway:
Patent application no. 20160104 (Norway)
FORCE Technology Norway AS
Method for detection of electric fields surrounding a structure in an electrically conducting
medium