As a manufacturer of solids control equipments and waste treatment equipments in China, GN Solids Control can provide customized solution for oil sludge treatment, oily soil treatment, drilling waste treatment. Soil pollution mainly come from oil & gas drilling, production and processing process, including oily sludge, drilling waste, oil sewage, and also produced during crude oil storage, transportation and processing, etc. contaminated soil. GN designed oily soil treatment system can achieve oily waste reduction treatment which will greatly reduce the total amount of oily waste and reduce the cost of subsequent harmless treatment. The oily soil waste treatment result can be recovery oil (Basic Sediment and Water in oil is less than 3% with proper chemicals), discharged solids ( oil content is below 2%) and water (which can be reused in the treatment process). For the contaminated soil washing process, firstly the contaminated soil should be grinded , crushed and separated the coarse solids, then washing process will be applied, the oily soil treatment is after the contaminated soil washing process.

The customized oily soil treatment solution including crushing pretreatment, material pre-mixing treatment, scrubbing pulping, first phase separation treatment double deck coarse shale shaker GNZS706F and mud heating and diluted, fine solids removal shale shaker GNZS594F separation, three phase decanter centrifuge GNSX554E-VFD with chemical dosing unit to separate oil, water and solids. The chemical dosing unit can add both dry powder chemicals and liquid chemicals. The three phase decanter centrifuge is based on the weight difference of solids, oil and water.
Due to the difference of specific gravity, the centrifugal force is different. The solids with the largest specific gravity and produce greatest centrifugal force, the water is the heavier phase liquid, the oil is the lighter phase liquid.
For the detailed working process, pls contact with GN solids sales.

To confirm if 2 phase separation decanter centrifuge can be applied for drilling fluids cleaning/ waste water treatment/ solids liquid separation project.
firstly we need to clear the pre-conditions of separation: 1) density difference (Layering inside the bowl) 2) rotary speed difference/ differential speed ( the solids and liquid can be discharged separately)

secondly we need to clear the material feeding requirement of decanter centrifuge: 1) solids content < 20%; 2)solids size < 500 microns, if not, the user could use pre-treatment equipment for primary separation, normally shale shaker, the user can use different mesh size shaker screen to control the solids content and solids size. Without adding chemicals, the centrifuge mechanical separation cut point is 2~ 7 microns.
The decanter centrifuge main components including bowl assembly, fluids collection box, main motor, back drive motor, cover, skid, inlet pipe, flushing port, fluids discharge port, gearbox, pulley with belt. The main motor drived the bowl through pulley and belt, the back drive motor drived the screw through pulley and gearbox. The bowl and screw with same rotary direction, different rotary speed, the differential speed generates. The VFD control panel with main motor, back drive motor and pump motor 3 VFD, the user can adjust the frequency of the 3 motors through PLC smart control and HMI interface. The engineer can use different frequency according to drilling fluids condition. The fluids pond depth can be adjusted as per requirement, to control the discharged solids moisture and treating capacity.

The decanter centrifuge working principal is as below:
The high speed rotating bowl generates a strong centrifugal force and sticks the solid particles with higher density on the inner wall of the bowl to form a solid layer: due to the low density of liquid, the centrifugal force is small, the liquid layer is formed inside the annular layer.

I don’t agree with that who say drilling cuttings are good for drilling fluids, he doesn’t realize the dangers of drilling cuttings to drilling fluids. The phenomenon that drilling cuttings increase the solids content of the drilling fluid will not be discovered very soon. The occurrence of this hazard has a certain process, so the increase in cost will not appear soon. I think that the cuttings will increase drilling costs, damage the reservoir, and increase the cost of drilling fluids treatment. During the drilling process, the solid phase in the drilling fluids is disposed of by the surface solids control system, after adding appropriate additives to make the drilling fluids meet the required performance specification, it is pumped into the well again, which is the meaning of the solids control system.

Shale shaker is the first phase solids cleaning equipment to separate big drilling cuttings, according to the drilling depth and required mud treatment capacity, the user can use 2 units shale shaker, 3 units shale shaker or 4 units shale shaker for option. The desander cone is the second phase cleaning equipment to separate solids size bigger than 45 microns, the desilter cone is the third phase cleaning equipment to separate solids size bigger than 25 microns. The user can use separate desander, desilter which without bottom shaker, or desander , desilter with separate mini bottom shaker, or mud cleaner with desander cone, desilter cone and bottom shale shaker 3 in 1, the discharged drilling cuttings will be much drier and drilling waste volume can be reduced.
Decanter centrifuge is the fourth phase cleaning equipment, the separation cut point is 2~5 microns.
The good solids control equipments can reduce drilling waste and recovery more drilling fluids, if you have any requirements of solids control equipments, pls contact with GN solids control.