Pilot unit for drill cuttings treatment Induction Thermal Desorption Unit (ITDU)
One of the main environmental concerns is pollution caused by oil and gas industry. Drilling process wastes pose the highest risk to natural environment. These wastes contain lots of various chemical agents with different level of environmental hazard. Lots of cuttings pits appear during oil and gas well drilling.
Content of oil products in drill cuttings is in the range from 2000 to 13870 mg/kg where 5,6% — gums, 20,1 % — polycyclic aromatic hydrocarbons.
When drill cuttings are heated at temperature 300 С°, toxicity level of drill cuttings is decreased by 10 times and at 500 С° drill cuttings are totally detoxified.
In 2014 four specialists of different disciplines from different countries joined into one team to design and manufacture pilot Induction Thermal Desorption Unit.
In 2015 pilot unit was tested in Tomsk in workshop of “Ambit” company. First successful results were obtained in March, 2015. In June, 2015 Norwegian company “Quality Group AS” made decision to manufacture ITDU-1.5 with capacity 1.5 — 2 tons / hour.
Drill cuttings are loaded to ITDU feed hopper by additional equipment and then feeding directly to ITDU process chamber by double-screw conveyor. Indirect heating of feed material takes place into process chamber. Process chamber is heated by induction to operating temperature, which may vary from 300 С° to 550 С° depending on chemical contaminants of feed material. High temperature allows drying of drill cuttings ensuring maximum removal of hydrocarbons. Specially designed shape of inductors allows to maximum heat process area where material is passing.
ITDU process technology is characterized as continuous process – 24 hours/day. ITDU is referred to “explosion hazardous” category.
Feed hopper with capacity 0,2 — 0,3 m3 is cone shaped. Feed conveyor is double-screw conveyor allowing to feed material with different viscosity. Feed rate is monitored by control system – frequency converter which allows controlling material volume in process chamber to maintain desired operating temperature. There is always some level of material in the hopper. Inlet material prevents air to come into process chamber and does not let gas to come out from chamber as well.
Level transmitter is installed on top of the hopper. This transmitter shuts down feeding conveyor if material level in the hopper is decreased (Critical level or minimum level required to keep chamber sealing).