ARKOIL Technologies developed and implemented its exclusive system for all types of storage tanks cleaning and hydrocarbons recovery in oil and petrochemical industries.
ARKOIL System
-Technology is based on transformation of steam energy and application of special tank cleaning nozzles;
-More than 1.000 (one thousand) of crude tanks have been cleaned by ARKOIL system;
-ARKOIL System is developed to operate in potentially hazardous zones;
-The System can be tailored to customers’ any special needs and/or requirements;
-Size of tanks can reach up to 200.000 m3, with fixed or floating roofs. The total amount of accumulated sludge is unlimited;
-ARKOIL Technologies has a very considerable experience in cleaning of damaged tanks.
Main Disadvantages of the Conventional Cleaning
-Low level of Quality, Health, Safety, Environmental standards;
-High risk of fatality accidents;
-Financial losses due to non-recovered oil;
-Logistic costs;
-Oil sludge utilization costs;
-Potential damage to the shell, roof and coating;
-Unreasonably expended time terms;
-Low quality of a final result;
-This method is unadvisable to be used for damaged tanks cleaning.
Advantages of ARKOIL Non-Man Entry System
-ALL TYPES of tanks, roofs & crude;
-The highest HSE standards: non-man entry, no emission, no chemical or additional crude used, no risk of explosion;
-Increasing efficiency of tank cleaning and desludging processes: cleaning & recovery performed simultaneously;
-Almost100% of oil recovery;
-Tanks cleaning excludes damar to the shell, roof and coating, if any;
-The system requires for several times less time-terms than a conventional method;
-Minimal quantity of solid sediments to be utilized;
-Complete neutralization of pyrophoric compounds;
-No weather or seasonal restrictions.
DESCRIPTION OF OPERATIONS
Mobilization: Equipment set up, energy/steam supply arrangements in accordance with potentially hazardous zones regulations. Depending on the tank’s diameter the required number of nozzles installed via the roof-5 days.
Steaming: Steam is supplied through tank cleaning nozzles directly into sludge. Steaming process continues until all sludge has been liquefied and separated into three fractions: oil, water and solid sediments. Operators constantly manage speed of steam supply and storage tanks’ surface temperature (+/- 55C°). Exact duration of steaming depends on quantity and composition – 14 days.
Hydrocarbons (HC) Recovery: HC are pumped directly to the pipeline or holding tank – 5 days.
Condensate drain: water is drained into the sewage or the same tank. No special water treatment is required and it can be treated internally – 2 days.
Ventilation: After the water drain, manholes should be opened to vent the tank. Once the tank atmosphere has been approved by a safety manager, personnel are admitted to enter.
Final Cleaning: At this stage no sludge left in the tank, only a layer of oil-contaminated solid sediments on the bottom. Roof, shell (coating) and legs are clean ideally and oil-free. Approximate quantity of sediments is 50-150 m3 in large tanks with capacity more than 50,000 m3 – 15-20 days.
Total for large storage tanks: around 40-50 days.
Result: tank is ready for maintenance and hot works.
QUESTIONS AND ANSWERS
QUESTION1
Do you use any chemical solutions in the cleaning?
ANSWER1
No. It helps to keep the technology green and environmentally friendly. Moreover, it helps to avoid any damage to pipelines or other facilities.
QUESTION2
Why do you claim your technology can help in fixing damaged tanks?
ANSWER2
The system does not require any staff presence inside the tank during cleaning and recovery stages. The process is safe and explosion-proof.
QUESTION3
Can the recovered oil be pumped into existing tank which is in service, or it must be pumped into another holding tank? This is during the sludge recovery period.
ANSWER3
There is no restrictions to deliver oil into an operating tank. There is no need to isolate a tank and treat it as a holding one. Recovered HC can be delivered to another crude tank which is operating 24 hours per day (during day and night shifts).
QUESTION4
What is the category of steam required?
ANSWER4
Steam parameters: quantity 2-5 t/hr (depends on tank’s storage capacity), temperature +150C°.
QUESTION5
Does ARKOIL tank cleaning technology require to drill New holes on top of tank roof, or you can use existing holes?
ANSWER5
New eruptions are not required as water and oil are pumped out from the existing sump/water drain-off or side manhole of the tank.
QUESTION6
How are the oil and water layers drained after being separated? Is there any need to weld new eruptions in the tank shell?
ANSWER6
New eruptions are not required as water and oil are pumped out from the existing sump/water drain-off or side manhole of the tank.
QUESTION7
How is the last part of solid sediments being removed?
ANSWER7
The solid sediments are removed manually but the quantity of these sediments is minor (around 50-150 m3).
QUESTION8
What is the indoor temperature at steaming stage? We are concerned that the required steam temperature at +150C° will disintegrate the primary seals of the floating roof, which have the maximum temperature of +90C°
ANSWER8
The temperature at the level of seals reaches +60C°- 70C°
QUESTION9
The ambient temperature in our region is higher (about +30C°) than the ambient temperature in The Netherlands (about +5 – 20C°). Will this cause more vapour to be emitted when the peripheral seals are opened for insertion of the tank cleaning nozzles by the engineer?
ANSWER9
The vapour emission due to the opening of the seals for insertion of the tank cleaning nozzles is insignificant. We have positive experience of working in regions with air temperature around +50C°.
QUESTION10
We are concerned that the recovered product will contain water (condensed) and hydrocarbons mixture, and the presence of water will inflate the final recovered volume of hydrocarbons. Moreover, the transfer of the recovered emusification containing oil and water into a holding tank might reduce the quality of crude oil?
ANSWER10
During the recovery stage only hydrocarbons are recovered (99.94%). Only at skimming stage there can be some unconsiderable volume of water in the mixture of hydrocarbons but even this can be excluded. The water left will never deteriorate crude oil in the holding tank. The process of recovery & skimming is being closely monitored by the client though constant sampling of the recovered product.