Centrifuge is a core separating machine. It utilizes centrifugal force to separate the particles and liquid from suspensions, or separate two different density and immiscible liquids from emulsions. Decanter centrifuge is a kind of centrifugal machine. It is widely used in oil and gas drilling field, for food industry, for chemicals, for waste water treatment and oily sludge separation.

Below is a general proposal for water base drilling fluids treatment.

As decanter centrifuge cannot allow big size particles and cannot treat high solids content material. Firstly, shale shaker or mud cleaner, desilter should be used to remove the bigger particles and reduce the mud weight. From this step, most particles over than 30 micron will be removed.

Secondly step, a middle speed decanter centrifuge (GNLW363CG, GNLW363CG, or GNLW452) can be used to further reduce the solids content in the fluids. Decanter centrifuge for this step can be fixed speed, and use a middle speed to reduce the mud weight. From this step, most particles over than 5 ~ 6 microns can be removed.

As the separation point of high speed decanter centrifuge is 2 ~ 5 micron. There are high content ultra fine solids cannot be treated. In this case, the chemical dosing system (also called dewatering unit) will be used before high speed centrifuge. Flocculant will be used in this step to help the solids settle down and easy for treatment.

A high speed decanter centrifuge (GNLW363CG-VFD, GNLW453C-VFD, GNLW553C-VFD) will be used together with the dewatering unit. Chemicals and drilling fluids will be mixed before enter into centrifuge bowl. The dewatering unit decanter centrifuge should be variable frequency control. Operator can adjust to find out the most suitable speed and G force to optimize the performance. GN offers different bowl diameter centrifuge for option: 14’’, 18’’ and big bowl 22’’.

After above treatment, the solids phase is dry enough for truck shipment, GN do also offers drill cuttings solidification unit for treat the solids.

And the fluids phase can meet the industry discharge requirement in most countries.