In Conversation
February 2017

In Conversation with: Raul Risi

In this issue of our “In Conversation with:” we are pleased to share with our readers some interesting thoughts and views from Mr. Raul Risi, Oil & Gas Division Manager of TTK. We would like to thank Mr. Risi for his efforts in comprehensively answering our questions which provide some highly valuable insights into the importance of Liquid Leak Detection Systems and the proper monitoring of underground storage tanks to ensure early stage detection of any leakages into the environment.


Mr. Raul Risi
Oil & Gas Division Manager
TTK – Paris

Currently, Raul is Oil & Gas Division Manager and Business Development Manager for Europe, Africa, Middle East & Asia at TTK.

Raul has twenty-five-year cumulated experience in Oil and Gas Industry as Division Manager (4 years), Project Manager (9 years) and Process Technology Design (12 years).

Before joining TTK, he worked in TOTAL E&P as manager of R&D activities related to LNG, Gas Treatment and Safety Engineering – Gas (2010-2012).

From 1992 to 2010, Raul worked in Technip. Spending twelve years (1992 to 2004) in the Process and Technology Division, he was Principal Engineer on gas treatment and LNG projects such as Yemen LNG and Nigeria LNG.

From 2004 to 2010, Raul was actively involved in the development of Technip Offshore LNG technologies as Project Manager - several patents filed, author or co-author of different publications on LNG transfer technologies.

Raul has also been member of:

  • the Foreign Advisory Committee on the 2nd Trondheim Technology Gas Conference, Norway, 2-3 November 2011
  • the Steering Committee on the SPE Forum "Economic and Sustainability Challenges in the Future Development of Sour Gas", Bali, Indonesia, 8-13 May 2011
  • the Technip “Experts Network” as “Main Expert - LNG” for several years
  • the Italian Register of Engineers

He holds a “summa cum laude” master’s degree in Chemical Engineering from Rome University “La Sapienza”.

Q: Can you please introduce your company and yourself to our readers, by sharing some of TTK’s history and own background experience with us?

A: TTK is one of the world’s major manufacturers of Liquid Leak Detection Systems. With 28 years’ experience, our expertise focuses in two fields: Oil Leak Detection and Water Leak Detection.

TTK’s headquarters, R&D center and the manufacturing facilities are based in Paris, France. We conceive, develop, manufacture in France and install leak detection systems in Europe, Asia, Middle East and North America via our subsidiaries or distributors.

TTK Liquid Leak Detection Systems are designed for: Oil Pipelines, Hydrocarbon and Petrochemical plants, Bulk Storages; Data Centres (chilled water pipes), Critical IT Infrastructures, Commercial and Administrative Buildings, Museums and Official Residential Properties.

Since the company was established, technology innovation helps us to deliver leading-edge liquid leak detection solutions. TTK technology is patented. We are always setting the pace for product development:

- In the early 1990’s, TTK was the first company which offered the digital range products.
- In 2011, TTK lead the industry to the new Millennium by introducing the first touch-screen and network connected digital panel on the market.

After I joined TTK, the first reusable, addressable Oil sensing cable, called FG-OD – allowing a true multi-leak system – has been finalised from a technology point of view and commercially launched end of 2013.

Since then, the system design and product range have been improved to cover a wide range of applications, some of them more and more challenging (e.g. very heavy oils, permanent contact with water / humid atmosphere, …). Our product catalogue now includes three sense cable references, having different sensitivities (low, medium and high), new references for oil sensor probe, as well as alarm and satellite units with different capacities.

Thanks to the permanent commitment of our technical development team, additional new features for oil sensing will be available soon, to even better suit our clients’ demands.

Following technology qualifications conducted with End Users and Engineering Companies, as well as solid references acquired in oil detection, our Business Development is boosting-up and TTK is hopefully becoming the preferred client choice and the reference technology solution in terms of liquid leak detection.

Q: Underground storage systems are an important factor in every oil company’s, storage terminal’s and fuel retailer’s daily business life. Can you share with us how the TTK Liquid Leak Detection System works?

A: TTK Digital Liquid Leak Detection System is based on addressable (thanks to electronic module embedded in each cable), liquid sensing cables connected to a monitoring panel.

Here is the working principle of our system:
- Our oil sense cable include a beam of wires (electrical conductors), protected by an external braid – cable structure being presented in the figure below.

- The wires are connected to an embedded microprocessor, located inside the cable connector.

- One of the wires is the sensing element, which includes a special silicone sheath, able to absorb hydrocarbon / oil while being impermeable to water.
- The silicone sheath is composed by :

  • an inner conductive layer, thanks to presence of carbon black particles
  • an outer non-conductive layer, providing electrical insulation to the sensing element

- In case of contact with hydrocarbon / oil :

1. The silicone sheath absorbs some of the product, and its volume increases locally.

2. In conjunction to such swelling, the electrical resistance of the sensing element rises (following distance increase between adjacent carbon black particles).

3. On the concerned cable, the embedded microprocessor detects the resistance rise and send an alarm signal to the alarm panel.

4. The alarm panel trigs a leak alarm indicating the concerned cable.

- The product absorption is reversible, so that the cable can be reused after cleaning (if required, e.g. non-volatile oils)

- Sensing string (circuit) composed by several interconnected cables - standard lengths of a single cable : 3m, 7m, 12m, 20m

- True multi-leak system : in case of leak, all the other sense cables remain operational and are able to detect and locate additional leaks

- When used for underground installation, the cable is inserted in a sleeve-protected slotted pipe as illustrated in the picture below, to keep it serviceable / accessible (e.g. visual / olfactory checking in case of leak detection, …)

Q: What makes the TTK Liquid Leak Detection System different from others? What are in your opinion the advantages of your system?

A: To properly answer to your question, let me first briefly provide some background relating to the “leak detection world”.

There is quite a broad panel of many different leak detection technologies, some of them being specific to the type of targeted application: underground storage tanks, above ground storage tanks, pipelines, pipe networks (e.g. airport fuel hydrant system), …

Generally speaking, leak detection technologies can be either internal or external.

Internal leak detection technologies, as well as some of the external ones, are not based on direct product sensing, rather on measurements of (indirect) physical parameters such as pressure, temperature, flow, level / volume, vibrations, Infrared wave absorption…

Whenever leak detection is based on indirect parameter measurement, there is usually a minimum leak rate which the specific technology is able to detect. Moreover, instrument calibration over time is critical and can significantly affect the minimum rate that can be detected. In real conditions, where different parameters change at the same time, the specific technology could either provide false alarms, or fail to detect even large leaks.

A relatively small leak which is going on for several weeks or even months would result on a significant spilled volume overall, likely provoking damages to the environment or even generate safety hazards.

Beyond theoretical considerations, operational experience relating to conventional leak detection systems has shown how difficult is reaching a reliable leak monitoring, despite the fact that a large number of different leak detection technologies is available today.

At this regard, examination of ten years’ span of US federal data from the “Pipeline and Hazardous Materials Safety Administration” (PHMSA), has highlighted that, between 2002 and July 2012 , leak detection systems in place detected only 5 percent of USA pipeline spills – over a total of 1,763 oil pipeline spills.

Moreover, only 20% of the very significant leaks (i.e. larger than 1000 barrels) were detected by monitoring systems in place.

For more details on PHMSA database and spill analysis, you can refer to the following article or visit PHMSA website: sense cable is based on external, direct sensing technology.

This allows TTK cable to sense the product presence (rather than its flow) outside the monitored equipment, so there is no minimum rate required for detecting the spill : even one drop of liquid (e.g. for refined products such as naphtha, gasoline, diesel, …) in contact with our sense cable would trig an alarm – though a less sensitive cable is also available on our catalogue, if required.

Consequently, since very small leaks can be detected, the first advantage of our cable - comparing to other conventional leak detection technologies - is the ability to perform early stage detection.

A second advantage of our sense cable is that, since the detection is not based on conventional instrumentation (that would require sufficient instrument precision and regular calibration), the system is reliable over time.

A third advantage is that our cable is reusable, which also allows testing the full system in real conditions:

- if a sensing cable is contaminated by a volatile liquid such as gasoline, the cable will rapidly dry by itself when exposed to open air

- if the contamination is by oil (such as gasoil), this latter is removed by immerging the concerned part into a volatile liquid such as naphtha or gasoline, and then by exposing the cable to open air as above.

Also, TTK sensing cable is insensitive to water: no false alarm due to humid or wet conditions.

Last but not least, the detection time is relatively short (e.g. compared to the time required for soil migration): e.g. less than 5 minutes when the cable is contaminated by gasoline.

Q: How much does your system cost? Are there any affordable solutions for the entire supply chain, from oil refiners, via distribution terminals to individual petrol stations?

A: TTK monitoring system is definitely affordable, which allows deployment through the entire supply chain: from refinery / tank farm to petrol stations.

The cost will depend on the particular installation, being function of several factors such as total number of sense cables and alarm units, cable lengths, overall market size with the same client, etc.

To provide some ballpark figures, here below the material cost of complete leak monitoring system - comprising all the required accessories such as slotted conduits, etc.:

- for fuel (gas) station (seven / eight different product compartments) : between 5 and 10k€.

- for bottom leak monitoring of a tank farm including above ground storage tanks of 25m diameter each : about 25 k€ per storage tank

Relating to installation cost, this is less than 30% of the material cost in most cases.

Q: Apart from the industry’s involvement, is there enough public awareness being generated? Do you view the support from non-industrial, political and commercial sources as sufficient?

A: What we note is that the awareness concerning the importance of having reliable leak detection in place sharply increases when spill incidents, engendering severe damage to the environment or the public health, occur.

At that point, usually new measures are quickly imposed by the regulatory authority to the different industrial and commercial operators.

Unless that point is reached, we also see that support from different stakeholders may not be sufficient to push having adequate measures correctly in place, unfortunately.

Nevertheless, we positively note a recent gradual increase of the general mindfulness relating to leak detection. As well, concerned technology experts become more and more conscious that new, reliable leak monitoring solutions are available today.

Q: Underground storage leaks have caused widespread problems even in technically developed regions. What do you think is the best approach to introduce, implement and monitor leak detection management in developing countries?

A: Different approaches for implementing leak detection in developing countries are possible, of course. We should distinguish between new units and retrofitting of existing ones - the installation cost being smaller for new units.

For new units, it is advisable that the design rules adopted in developing counties be similar to the one used in developed countries, where adequate leak detection systems are put in place – e.g. : use of double wall storage tanks provided with interstitial leak detection.

Such an attitude would allow having a gradual increase of CAPEX investments in leak prevention by taking advantage of technology progresses, while minimizing future OPEX on the same installations in the middle term, thanks to the more robust design.

For retrofitting, e.g. of single containment underground storage tanks, I would suggest the addition of a leak monitoring system based on two possible approaches:

1. Sense cables added at the top of the storage tanks as per the drawing below.

In this case the slotted conduit containing the sense cables is installed in a shallow trench (e.g. 20 -30 cm deep), so that the installation cost as well as the risk of damaging the underground system are minimized.

In such a configuration, gasoline or diesel oil spilled in a wet or compact soil would preferentially go upwards (thanks to density difference), then being rapidly spotted by the sense cables.

2. Sense cables installed inside narrow, shallow, vertical pits (e.g. 7-12m deep), drilled close to the storage tanks: to monitor possible soil / groundwater contamination.

Q: In an ideal world all kinds of groundwater contamination should be avoided. ACFA believes that "No Leaks" is the ultimate but the only responsible way for fuel retailers and for governments to strive for and implement. Do you think a complete leakage prevention situation is achievable? How can your system help to achieve this? Are there any early-warning/monitoring devices available?

A: I definitely agree with ACFA statement relating to “No leaks” approach.

I believe that it is always possible to put in place adequate measures to ensure that “No leaks” situation is achieved, whatever the type of installation: refinery, pipeline, above ground storage tank, retail network, …

The architecture of the most appropriate sensing system highly depends on the application - oil system to be monitored.

For example, on the fuel service stations, I would suggest:

  • Firstly, using double wall storage tanks properly protected against corrosion and provided with interstitial leak detection. TTK sense cable can be easily adopted at this end.
  • Secondly, installing sense cables to monitor the manifold chamber as well as the storage tank turrets.
  • Last but not least, installing sense cables inside vertical pits at specific locations to monitor possible soil / groundwater contamination. This would allow detecting possible spillages from any source within the station. Including the ones from dispensers that should be properly collected via the draining and disposal system.

Since our cable is very sensitive, it will provide early warning in case of spill / contamination whenever installed in a proper location.

Q: We very much appreciate your contribution to this interview and we would like to provide you the opportunity to address any other issues you may wish to raise which have not been captured by our questions.  

A: I would like to warmly thank ACFA for providing this opportunity to digress on a sensitive argument such as the leak detection.

I am confident that “No leaks” approach will become more and more the standard one, hopefully in a near future also in developing countries.

This ambitious goal can be reached by adopting appropriate equipment design and proper installation layout, taking advantage of the different technology improvements now available on the market, including reliable leak detection systems such as the ones based on sense cables.

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