In a Nutshell:

Even today, tank inspection remains a complex task with challenges both expected and unforeseen. Service engineers work in almost complete darkness, performing to the best of their ability in unpleasant conditions while inspecting and searching for any repairs the tank may require – the environment notwithstanding. While you could say that this is the norm for any tank inspection, there is no doubt that anyone tasked with this job would be glad to have the support of equipment to make the process easier. In this case, experts from our Asia Pacific region were looking to carry out a tank bottom inspection for a Malaysian customer using our TBIT Ultra technology.

APPROACHING THE CHALLENGE

A client located on the East Coast of Malaysia had recently requested a tank bottom inspection of a condensate tank with an external floating roof, which required a visual inspection, bottom plate numbering and a tank bottom drawing. The client also required that a 1,493 mm² area of the tank bottom be inspected without removing any internal obstructions, which increased the difficulty of the task. Fortunately, the service engineers were able to bring along ROSEN’s most recent addition to its toolset: TBIT Ultra.

Figure 1 – Our latest floor scanner, the TBIT Ultra

Figure 1 – Our latest floor scanner, the TBIT Ultra

The Solution

Equipped with sensors that offer 6.7 times the resolution of previous models, the new features would also enable a more efficient approach to this particular task, with more accurate signal-based sizing, an improved ability to scan through thicker coatings, a new capability to measure remaining coating thickness, maximized scanning of surface areas, early detection of microbially induced corrosion (MIC) on features as small as 2 mm in diameter, and flexibility when working within and around critical zones and obstructions, such as scanning below heating coils, which typically must be removed in order for a scan to be conducted. These new features would help tremendously in meeting the client’s requirements for the inspection of the tank bottom without any additional intervention.

Figure 2 – Increased sensitivity and precision using TBIT Ultra technology

Figure 2 – Increased sensitivity and precision using TBIT Ultra technology

Time to get scanning

After an initial walkthrough of the tank and a successful kickoff meeting, it was agreed that ROSEN’s regional service engineers would begin work using our TBIT Ultra technology. The reason behind choosing this technology was the high probability of detection (POD) and higher inspection coverage with reduced blind zones of the tank bottom inspection. Additionally, the client was looking for a short inspection window. The tank bottom was revealed to be generally clear of residual matter, except for rust debris discovered on the tank floor.

Figure 3 – Service engineer during tank bottom inspection

Figure 3 – Service engineer during tank bottom inspection

To complete the scanning, our local team used TBIT Ultra technology, which was easily deployed thanks to its ability to maneuver under the low external floating roof and internal piping via remote control. This avoided unnecessary dismantling work and allowed us to easily fulfill the client’s requirements. Thanks to the tool’s ability to scan in a curvature line, particularly around the annular plates, TBIT Ultra also managed to cover more than 95% of the tank floor. Thus, it provided more Magnetic Flux Leakage (MFL) data than other scanners and enabled more accurate metal loss detection, which made it possible for the team to perform an online evaluation and immediately report the required length, width and depth information.

The recorded high-quality data ultimately allowed the client to make better decisions regarding the tank’s preventive maintenance. As shown in Figure 4, our local experts were able to collect all MFL indications under the obstructed area (piping).

Figure 4 – Results of the tank bottom inspection

Figure 4 – Results of the tank bottom inspection

Looking ahead

Both the working team and the client were pleased with the successful run and efficient approach to the tank bottom inspection. Thanks to the new technology of the scanner, the job was made far easier, safer and more efficient, always keeping the future of the asset in mind. With our solutions being tailored to the individual needs of our clients and with the help of our regional experts, we were once again able to successfully complete a project using our TBIT Ultra technology.

Authors

Sherman Anthony Nunis

Boasting more than 20 years of tank inspection experience in the industry, Sherman Anthony Nunis currently heads the non-disruptive technology division in the Asia Pacific region. He started his career as a certified inspector and has gathered vast knowledge working in the oil and gas sector across the globe. He is a visionary and leads a team driven to deliver continuous innovation in the inspection market.

Asral Mohamed

With more than 15 years of experience in the oil and gas industry, Asral Mohamed has gained valuable experience with Magnetic Flux Leakage (MFL) TBIT over the past eight years. Having been with the company for more than eight years, Asral now serves as a workgroup lead for ROSEN Asia Pacific.