FPSO Tank Sludge Removal: Air-Operated Vacuum Transfer for Offshore Tank Cleaning

Thirty metres below deck, access becomes part of the pumping problem.

So does the vertical distance back to the receiving point.

Then add tank-bottom sludge, solids, restricted hatches and the need to reduce labour-intensive material handling, and an FPSO tank-cleaning operation quickly becomes more than a conventional pumping exercise.

This is one of the applications where SupaVac has documented field experience.

For Takmeel Global, that makes FPSO tank sludge removal an application worth evaluating around real operating parameters rather than generic pump claims.

A Documented SupaVac FPSO Tank-Cleaning Case

SupaVac has published an FPSO project in which the operator’s previous sludge-removal method used buckets and winches.

According to the manufacturer, that method was achieving approximately three tanks during a day shift using two crews and two winches.

For the project, SupaVac supplied three SV60-V2 units configured with vent-to-atmosphere.

The pumps were lowered approximately 30 metres into the tanks through restricted access hatches and transferred solids vertically more than 30 metres to the top deck.

SupaVac reports that, in this specific application, the customer subsequently achieved:

• 7–10 tanks cleaned per day per crew;
• approximately 50% lower onsite personnel requirements compared with the previous method;
• a manufacturer-reported 650% acceleration in tank cleaning.

These figures are valuable because they relate to an actual documented project.

They should not be presented as guaranteed results for every FPSO.

Every tank layout, sludge condition, hose route, air supply and cleaning procedure is different.

Why FPSO Sludge Removal Is a Unique Transfer Problem

An offshore tank-cleaning system must often solve several problems simultaneously.

The material may contain:

• oily sludge;
• sediment;
• scale;
• sand;
• solids;
• slops;
• contaminated water;
• heavy hydrocarbon residue.

At the same time, the equipment may need to operate through:

• small tank openings;
• long vertical lifts;
• limited deck area;
• complex hose routes;
• controlled waste-receiving points.

A pump therefore cannot be evaluated only by nominal throughput.

Access and transfer geometry are equally important.

SupaVac’s Official Marine Applications

SupaVac lists the following marine applications within its current application portfolio:

• FPSO tank cleaning/desludging;
• bilge cleaning;
• spill management;
• vacuum cleaning of barge and vessel bottoms;
• barge and hull cleaning waste recovery.

Its wider oil-and-gas applications also include tank cleaning/desludging, petrochemical tank cleaning, oil sludge and tank-bottom residue transfer, heavy crude transfer and slops sump cleaning.

This gives the technology relevance to FPSOs, FSOs, tankers, barges, shipyards and offshore maintenance contractors dealing with difficult sludge and solids.

SV30: Designed for Small FPSO Access

The SV30 is particularly noteworthy for marine applications.

SupaVac states that the SV30 was specifically designed for small FPSO applications and can be lowered through service hatches into restricted areas for sludge removal.

The manufacturer also lists tank cleaning, bilge cleaning and tank-sludge extraction among its applications.

Its compact dimensions and 66 kg published weight make it a model worth evaluating where physical access is a dominant constraint.

Again, access alone does not determine suitability. The sludge and transfer duty must also fit the pump’s operating range.

SV60-V2: Proven in a Documented FPSO Application

The SV60-V2 is directly relevant because it was the model used in SupaVac’s published FPSO tank-cleaning case.

The SV60-V2 is a portable compressed-air-operated solids pump with manufacturer-rated throughput up to 27 m³/hr at SG1.0.

Its official applications include tank cleaning and sludge extraction.

In the documented FPSO project, the relatively compact units were physically lowered into the tanks and discharged material vertically to deck level.

That real-world application is more useful than simply describing the unit as a “marine pump.”

Larger Marine Solids-Transfer Duties

For heavier or larger-scale marine applications, other SupaVac models may also be evaluated.

The SV250V officially lists barge and hull cleaning as an application.

The SV510 lists:

• oil sludge and tank-bottom residue transfer;
• tank cleaning and sludge extraction;
• vacuum cleaning of barge and vessel bottoms;
• heavy crude transfer.

These references demonstrate the breadth of SupaVac’s marine and tank-cleaning application range without implying that every model is appropriate for every FPSO tank.

Bilge Sludge Removal

Bilge areas can contain mixtures of:

• oily water;
• sediment;
• sludge;
• solids;
• debris.

When the material becomes solids-laden, the requirement moves beyond straightforward liquid transfer.

SupaVac explicitly lists bilge cleaning as an application, including on the SV30 product page.

For vessel-maintenance contractors, a compact solids vacuum pump can therefore be worth evaluating when bilge material is difficult for conventional liquid pumps.

Slops and Tank-Bottom Waste

Slops may contain variable proportions of oil, water and solids.

That variability matters because pump performance can change significantly as solids concentration or viscosity increases.

Rather than defining an application as simply “slops transfer,” Takmeel recommends establishing:

• actual solids content;
• SG;
• viscosity;
• particle size;
• suction geometry;
• discharge destination.

SupaVac’s oil-and-gas application list includes slops sump cleaning, tank cleaning and oil-sludge/tank-bottom residue transfer.

Why Vertical Lift Must Be Treated Separately

Offshore enquiries often state a single transfer distance.

For example:

“The pump needs to move sludge 50 metres.”

That is insufficient information.

We need to know whether the 50 metres consists of:

• 5 metres horizontal + 45 metres vertical;
• 45 metres horizontal + 5 metres vertical;
• or a more complex route with several changes in elevation.

In an FPSO tank, vertical suction and discharge requirements can dominate pump-system design.

Always provide four measurements separately:

Horizontal suction distance

Vertical suction lift

Horizontal discharge distance

Vertical discharge elevation

This gives a much more useful picture of the duty.

Compressed Air Must Be Verified Before Mobilisation

SupaVac pumps are pneumatically powered.

The appropriate compressed-air supply therefore has to be confirmed before the unit is selected or mobilised.

For the SV60-V2, SupaVac publishes approximately 150 cfm air consumption at its stated operating pressure. Larger units can require significantly more compressed air.

A project team should confirm:

• compressor capacity;
• operating pressure;
• air-hose diameter;
• air-hose distance;
• simultaneous air users.

An otherwise suitable pump can underperform if the available air package cannot support it.

Hazardous-Area Considerations

The SV30 and SV60-V2 currently carry manufacturer-listed ATEX Zone 2 conformity.

This should not be generalised into a statement that every SupaVac configuration is suitable for every classified offshore area.

For each project, verify:

• selected model;
• actual certification;
• tank/area classification;
• operator requirements;
• project HSE procedures.

Certification should always be checked against the specific duty.

Can SupaVac Reduce Manual Sludge Handling?

The documented FPSO case provides useful evidence that a mechanised vacuum-transfer approach can significantly change the way sludge is removed.

In that specific project, SupaVac reports lower manpower requirements and substantially faster tank-cleaning rates compared with the customer’s previous bucket-and-winch method.

However, this should not be interpreted to mean that a SupaVac pump removes every need for:

• tank entry;
• washing;
• inspection;
• gas freeing;
• isolation;
• final cleaning;
• other site-specific tank-cleaning operations.

Its role is specifically in improving the recovery and transfer of difficult sludge and solids.

That distinction is important for responsible project planning.

SupaVac and Vacuum-Truck Dependency Offshore

Onshore tank-cleaning projects may have the option to position a vacuum truck relatively close to the tank.

An FPSO presents a different physical environment.

Portable or compact vacuum-transfer equipment can be positioned within the asset and connected by hose to an appropriate receiving point.

This does not make a SupaVac universally equivalent to a vacuum truck.

The two systems perform different functions.

Where the primary challenge is recovering sludge from a difficult offshore location and transferring it through a hose system, an air-operated solids vacuum pump may provide a particularly relevant alternative method.

What Takmeel Needs for an FPSO Application Review

Send us:

Asset:
FPSO, FSO, tanker, vessel, barge or other.

Tank/application:

Material:

Approximate solids percentage:

Maximum solids size:

Specific gravity:

Viscosity:

Temperature:

Horizontal suction distance:

Vertical suction lift:

Horizontal discharge distance:

Vertical discharge elevation:

Required transfer capacity:

Compressed-air pressure:

Available compressor capacity:

Area classification:

Access/manway dimensions:

Continuous or intermittent operation:

Photos or videos of the actual material and access area can also be useful during preliminary assessment.

SupaVac FPSO and Marine Solutions from Takmeel Global

Takmeel Global is based in Dubai and is listed within SupaVac’s official distribution network.

We support customers across the GCC evaluating SupaVac equipment for tank sludge, marine waste, bilge cleaning and difficult solids-transfer applications.

If you are planning an FPSO, FSO, tanker or vessel-cleaning project, send us the material data, access conditions, transfer route and compressed-air availability.

We can then review which SupaVac model and configuration should be evaluated for the actual duty.

Takmeel Global General Trading LLC
Dubai, UAE
Mobile: +971 52 692 2575
Office: +971 4 256 4920
Email: info@takmeeltrading.com
Web: www.takmeeltrading.com