Tank Cleaning

PROKLEEN uses three methods of tank cleaning services; Manual method, Downhole nozzle application method and Sludge Master Solvent Extraction method.

The following information is based on Prokleen tank cleaning practices for downhole nozzle application method.

A) Process and Equipment:

1st) It is in the best interest of the customer to recover as much oil as possible without significant solids contamination. This oil can be economically processed as crude unit feed rather than as a slop stream which is usually a refinery bottleneck.

2nd) The crude remaining in the tank is diluted with an available hydrocarbon like diesel, kerosene or jet fuel and is pumped off until analysis shows that the crude available above the sludge is minimized. This is done in a bath process, and permits maximum economic oil recovery.

3rd) The next step is to introduce water and JPX into the tank to wash the sludge and float the dispersed oil to the surface for recovery. In order to contact the sludge with wash mix, the sludge must be agitated to facilitate wash penetration. This is accomplished in various ways like : side entry mixers, butter worth type mixers, and rotary nozzles inside man ways or the roof ports. Many different types of rotating nozzles are available to agitate the sludge and allow wash mix contact. The number and location of the nozzles as well as flow rates would depend on the tank’s access port number and location.

4th) The wash sludge mix is pumped from the tank and decanted to recover the oil and settle the sludge.

5th) If sour odors are present, then an additized version of JPX, JPX-E , can be utilized to eliminate the problem.

B) Products dosage and application:

1) Quantity: 2% to 5% JPX in the volume of water utilized.

2) Dilution ratio: ~25-1 With water. Do not use sea-water. Salt will reduce effectiveness of cleaner.

3) Temperature of injection: Product is effective at room temperature, but it will be increasingly effective at

higher temperatures up to 160 F.

4) Application through spray nozzles: Premix the JPX with water before use.

5) Removal of Benzene , LEL and H2S: JPX will remove benzene and reduce LEL. Consider application of JPX-E for sour materials.

C) Methods for leveling the uneven sludge height : Use high-pressure nozzles:

• Spray Nozzles

• Water draw

• Baker tanks

• Pump at flow rate based on nozzles specifications & number

• Method for heating : steam via exchanger

• Time for cleaning: weeks

• Time for de-emulsification: hours

• Condition of remaining waste: unknown

• Hazardous waste: heavy metals

• Sampling: Obtain sample of sludge by thief device &

test with diluents & JPX for concentration impact.

• Test sludge for % of oil concentration.

D) Disposal:

If refinery has a delayed coker, water and dirt emulsion can be disposed of as quench water to coke

Prokleen Sludge Master Tank Cleaning Technology

Prokleen Nigeria Limited uses the latest equipment in its tank cleaning operations. The Sludge Master Jet Nozzles is the latest technology for cleaning Crude Oil and other tanks containing heavy sludge. The Sludge Master Jet Nozzle can be mounted on tanks where the sludge levels are above the man ways using an adapter flange and cold tap and the customer wants to recover the oil. This method eliminates the need to hot tap. Generally , crude oil is 90% recoverable as a usable oil .The Sludge Master /Tank sweep jet Nozzles are designed to circulate, suspend and fluidize the sludge using the existing oil in the tank, although a better recovery rate can be achieve using a solvent that’s made in the refinery such a light cycle oil or unfinished diesel.

SludgeMaster has a flow rate of 660m3/hour @ 10bar.One SludgeMaster has the capacity to clean up to a 31m diameter tank. For 90m diameter tanks at least 3 SludgeMaster are required .They can be mounted on the tank’s existing man ways , regardless of the sludge/oil level, without having to hot tap the tank.

Tanks with 1meter or more of sludge can be circulated, fluidized, and pumped out in as little as 3-5 days depending on the sludge profile and the customer’s needs.

Selective Solvent Extraction Method.

This method liquefies the organic compounds in the sludge without using expensive chemicals, returning valuable hydrocarbons to the customer and significantly reducing waste disposal while cutting the cleaning time by almost 2/3.


The SludgeMasters are mounted on the tank.

The tank is emptied of all oil.

The roof is then refloated with a solvent.

Tank is then circulated and heated to suspend and dissolve the solids.

What we can do for your company:

Cleaning crude oil and other heavy oil tanks have a history of being expensive, time consuming, and generate solid waste and it is a science that most companies have yet to master. We can offer your company the following benefits from using our system:

• Significant reduction in tank cleaning costs.

• Cut your tank out of service time for cleaning.

• Return tanks to service faster.

• Decrease margin/debit loss from not having the tank available for product.

• Reduce your waste disposal by 90% in most cases.

• Reduce personnel exposure to hazardous materials.

Solvent Extraction is;

• Safe

• Effective

• Environmentally friendly

• Simple to execute

We also;

• Clean and Coat Tanks (Adisa Tank coating system)

• Pipeline Cleaning

• Perform sludge measurement

• Oil and Gas Safety

• Write step by step Tank Cleaning Procedures

• Teach Safe Tank Entry Procedures

• Pressure Vessel Cleaning.

• Petrochemical cleaning

• Opening /Blinding Permits

• Atmospheric Vessels

• Entry Permits, including vessel entry.

Finally we can assure you that the dollars you will save from our oil recovery will be much more than what it cost to do the work. For example, you are going to recover around 90% of the sludge as a useable oil. For instance, if you recover 10,000 barrels of oil, multiply that by the current cost of a barrel of oil. You have also eliminated 90% of what it would cost for disposing of the sludge.

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