Common Problems Inside Storage Tanks

Common problems inside storage tanks are related to emulsion, water and solids as they cause production stops and may damage equipment if they enter the outlet. Knowing the tank's level, layers and their interfaces are vital for assuring continuous production and high-quality throughput. Any and all problems regarding storage tanks can rack up the costs to a sky-high number, whether it is from treatment costs, deferred production, unplanned - or even emergency - shutdown.

Storage tank is a challenging environment and knowing it's actual contents is a real challenge. Traditional instrumentation may struggle with contamination and emulsion, manual sampling is a major HSE risk and while nucleonic devices may be unhindered by the conditions, the speed and ease of use is a challenge itself.

Challenges in tanks and flow assurance.

Rocsole's Solution and Benefits

Here at Rocsole, we've developed our systems to work accurately in hostile environments without posing any HSE risks or without the burden of handling nucleonic devices, while offering a real-time profile of the tank. The systems consists of a computer, an electronics cabinet (IECEx certification available) and the sensor - Rocsole Tank Profiler.

Rocsole's solution allows the operator to get the process in­sights of the tank emulsion layers and level interfaces without any interruption due to complex process fluids. The sensors are virtually unaffected by surface fouling and contamination and works in harsh environments providing rich data allowing for re­al-time monitoring and predictive analytics. We provide process insights for stable emulsions, rag layers, bitumen, froth layers and solids buildup.

  • Avoid H2S safety risk when working with manual samples in tanks
  • Safe, improved HSE
  • Reduced admin
  • Oil field life cycle optimization
  • Increased production throughput
  • Reduced need for Shutdowns & optimized chemical costs
  • Improved separation efficiency by optimizing the emulsion
  • Real-time process optimization
  • Improves asset environmental compliance
  • Low maintenance
  • 24/7 data monitoring all data to database

Liquid In-Tank Inspection (LITI)

We also use Tank Profiler to provide Liquid In-Tank Inspection service, in which we scan the tanks contents on-site and deliver the results soon afterwards.

This is the easiest way to inspect the contents of one or more tanks in one go at a minimal cost in processes where no real-time results are required.

The services can be done on a permanent basis, on a regularity or by-demand. Rocsole is the first company bringing tomographic imaging to the oil & gas industry enabling a new level of process optimiza­tion for challenging operations to provide better product quality, higher output, reducing operational costs and improving safety levels.

In Liquid In-Tank Inspection (LITI), each of the tanks' contents are scanned and the results delivered later.

Rocsole Tank Profiler

To reap the benefits of the Tank Profiler, it is available in two flavours:

  • A permanent installation
  • As a service (Liquid In-Tank Inspection or LITI for short)
Installation options of Rocsole Tank Profiler including Liquid In-Tank Inspection (LITI).

With permanent installation, we deliver the Tank Profiler system for you. It is easy to install and does not require modifications to the target. Commissioning can be done remotely or on-site.

The image above shows a sensor for detecting and locating oil-water interface in an open caisson. The cable is approximately 30 meters / 100 ft. long.

Complete Multi-Sensor Monitoring Solution

In processes where knowing the true content of a tank is only part of the battle, Rocsole's Tank Profiler can be combined with one or more additional Pipe Sensors which are installed to tank's inlet piping, outlet piping or both.

Tank monitoring with Tank Profiler and Pipe Sensor combination.

Benefits of multi-sensor systems are apparent; not only the tanks contents can be accurately profiled, but by monitoring inlet and outlet piping, preventative or proactive measures can be taken if there are any temporary irregularities in the flow. By knowing what is coming through the inlet, it is significantly easier to estimate e.g. the water content, which helps in administering the correct, sufficient amount of emulsifiers and other chemical agents.

While this is happening, Tank Profiler monitors the events inside the tank and gives further insight about the required residence time and dosages of chemical agents. Especially in greenfield projects, the quality of mediums vary from well to well, making it tough to apply same parameters every time. So far manual sampling has held it's position, but it is time-consuming and poses major health risks for the staff on-site.

Finally, if one or more Pipe Sensors are installed to outlet piping, it can be used to monitor the quality of oil, the quality of the wastewater, or both. Monitoring the quality of wastewater is exceedingly important as the treatment costs can become a major expense; up to $ 3 USD per barrel of wastewater. Considering that on average, producing one barrel of oil produces three barrels of wastewater during the whole process, treatment costs are measured in millions, and a failure to comply with the regulations regarding it's treatment or disposal may carry out hefty sanctions. Therefore, using all the available information to optimize the process creates considerable savings every year.

Rocsole Profiler vs. Nucleonic Device

We have also conducted tests in which we compared our Profiler's performance against nucleonic device. Rocsole Profiler was installed to a separator in a medium scale three-phase flow loop. Test runs were performed between November 6th, 2018 and November 26th, 2018.

Raw measurements were recorded with approximately 1 Hz frame rate. 127 density profiles were recorded with a nucleonic gamma scanner. Gamma scanner moves vertically and gives point-wise measurements (one complete scan taking 15-20 minutes).

Profiler measures conductivities, which are converted to water cut and then compared to profiles produced by the gamma scanner. The table below shows result comparisons of both sensors with a one minute time resolution.

Rocsole Profilers are See Beyond compliant.

As the Profiler utilizes Rocsole's See Beyond technology, which means that it is not affected by contamination unlike traditional instrumentation, all the results from the Profiler are computed with a same set of algorithms and parameters and without calibration in between the measurements.

The purpose of the test campaign was to verify the performance of the Rocsole profiler vs. typical nucleonic device (reference)
Rocsole Nucleonic
Measurement time 1 second 15-20 minutes
Installation type Fixed Vertical movement
(0.04 in/s, 1.00 mm/s)
Operating principle Electrical conductivity * Density *
Rocsole profiler was installed in a 3-phase separator in a closed medium scale multi-phase flow loop. Test runs were performed between November 6th, 2018 and November 26th, 2018.
Note that Gamma water cut (cyan) is closer to the first water cut profile in the bottom part of the tank …and close to the last profile in upper part of the tank.
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Delivery Content of an IECEx Certified Tank Profiler (cabinet-on-tank installation)
Delivery Content of an IECEx Certified Tank Profiler (cabinet-on-tank installation)
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Delivery Content of an IECEx Certified Tank Profiler (cabinet-on-ground installation)
Delivery Content of an IECEx Certified Tank Profiler (cabinet-on-ground installation)
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Delivery Content of LITI service (temporary installation)
Delivery Content of LITI service (temporary installation)
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Request a Tank Solution

Need a solution or something different? Contact us, and let us worry about the rest. We can modify the design to fit your tank perfectly.

We are here to help you, don't hesitate to contact us!

Pekka Kaunisto

Pekka Kaunisto

Vice President Sales +358 40 024 0707
Harri Hedman

Harri Hedman

Chief Marketing Officer +358 40 166 3871
James Walls

James Walls

Regional Sales Director +31 61 466 9435
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