Automated Cleaning Process

Process Simulation

Mechanical action of continuous mixing in a stirrer for a determinate time (100 rpm)

Chemical Action

Chemicals concentration tested at different levels vs sludge volume
Crude oil volume vs sludge volume tested to check chemical injection process

STEP 1

Sludge Mapping & Characterization

Mapping

Thermographic, density and viscosity profiles are taken to determine the quantity of sludge

Characterization

Sampling, density & viscosity profiles and analysis of the sludge enable the optimal tank cleaning strategy to be developed.

Parameter	Method
H2O Marcusson	ASTM D95
Soxhlet Oil	EPA 3540C
Soxhlet Residue	EPA 3540C
105 C Residue	APHA 2540G
600 C Residue	APHA 2540G
Asphaltenes	IP 143

STEP 2

Cold Tapping

Without opening the tank, several bolts are removed from the lateral man-way, leaving 8 bolts in place.

The manhole adaptor, with a gasket, is placed over the man-way and bolted down. The adaptor has 8 larger holes to fit the man-way plate bolts.

Two side valves (10” and 6”) and one 16” (front) valves are installed on the adaptor. The valves are closed and the assembly is leak tested.

Without taking the tank out of service, a cold tapping device is used to cut the man-way.

The cold tapping device is bolted in place

The main valve is opened and the cutting head cuts into the man-way flange.

STEP 3

Installing Telescopic Jet

The cold tapping device is removed and replaced by the telescopic jet. The tank remains in service throughout this operation.

STEP 4

Circulation System

Circulation The position of the jetting tool is controlled hydraulically or manually. The range of the jetting tool is:

+/- 20° vertically
180° horizontally

The washing and dilution effect of fresh crude is from the lowest tank level (maximum specific energy) to the highest (maximum paraffin dispersion). Circulating

Circulating while filling the tank
Paraffin suspension and dispersion with mechanical action and chemical injection

Without taking the tank out of service, we are able to run desludging phase according to your offloading program. It means that we can start circulating as soon as you need to fill the tank, we will stop circulation early enough to permit water and sediment settling. Quality control, sampling and analysis will be done every three hours during this phase. Crude oil quality will not be affected.

STEP 5

Separation

Paraffin dispersant/surfactant agent action:

Allows oil, fats and hydrocarbons to disperse into water through reduction of surface and interfacial tension.

A temporary stable emulsion is formed which afterwards breaks allowing the hydrocarbons, water and solids to separate in layers.

At the end of the circulation, or more if necessary, the oil and water are separated from the solid phase.

Sludge consisting of sand and gravel mixed with oil and water.

Sludge now has up to 95% of the hydrocarbons removed and returned to the oil phase.

Hydrocarbon can be recovered by customer to be sent to a tanker. After last circulation to empty the tank (if needed) crude oil will be recovered from the 10” valve and thereafter from bottom drains.