drilling fluids

GN solids America has 2 units of variable frequency drive decanter centrifuge in Houston warehouse, we accept to make test firstly in the factory before shipment, welcome to contact GN solids sales to arrange for a test.

Working principal of VFD decanter centrifuge:

GN use Netzsch Brand NEMO pump to feed the drilling mud into the feed tube and flow to the centrifuge bowl, the bowl rotates high speed under , the screw conveyor, which is inside the bowl ,get a differential speed through the gearbox. The bowl and conveyor compose the pulley and belt with the differential speed and rotates in the same direction.

Under the working of different centrifugal force , the heavier solids paticles is pushed to the inner bowl and pushed theought the screw to the solids discharge port, the lighter weight fluids is settle down and discharged through the fluids output port, which with 6pcs adjustable dams to adjust the fluids pond depth inside the centrifuge bow.

Viriable frequency drive decanter centrifuge can adjust the screw rotary speed to achieve different working purpose. For example, when start the centrifuge, firstly you start it with a low frequency to get a lower electric currency to protect the VFD control panle, when it works stably, you can adjust the frequency to your required data to get your required performance. For the drilling mud with high gravity solids, 2500rpm rotation speed is required; for the drilling fluids with low gravity solids, 3200rpm is recommend. To collect the barite, 1800rpm is recommend. But such recommendation is just for oil & gas drilling, not inludes food, waste water, etc.

Applications of GN decanter centrifuge

1 solids control system, working to separate fine solids 2~5 microns

2 drilling waste managements system, working to separate the fine solids from the recycled mud from linner shale shaker

3 Liquid mud plant, working to separate fine solids and re-mix the drilling fluids, which can be re-used by the rig.

Mud System Check List


General description of Hydraucyclone desander desitler

Hydraucyclone is a normal parts used for mining industry, for drilling field, for waste water separation, soil depuration. In drilling field. Hydraucyclone can be used as desander desilter per different size. Or combined with shale shaker to work as mud cleaner. 

Big size desander cone normally used for mining, piling or CBM drilling.  Hydraucyclone for desander desilter in drilling fieldi usually small size:

1) Hydraucyclone for desander: 12inch, 10inch

2) Hydraucyclone for desilter: 5inch, 4inch

Main parts of Hydraucyclone for desander desitler. Take example of 4 inch desilter cone, it is components of below parts:

1) Shell

2) Cone tube

3) Drop in Apex

4) Orifice nut

When combined for a desilter machine, elbows and clamps, ball valves will be used for connection.

Principle of Hydraucyclone for desander desitler

Hydrocyclone is a cylindrical part of the conical vessel. The upper part of the internal cone section called the liquid cavity. Cone outside is provided with a liquid inlet pipe, and the liquid cavity is communicated to the tangential direction. The top of the container is the overflow port, the bottom is underflow (also called the discharging port). Cyclone size is determined by the maximum diameter of the cone. Its working principle is centrifugal sedimentation. Because of the coarse particles and fine particle size difference exists (or density difference), the centrifugal force, under the centripetal buoyancy, drag force of different sizes, due to the centrifugal sedimentation, pyramidal intermediate creates a low pressure area, forming a column of air, caused by vacuum suction effect, play, most of the fine particles in the cyclone under the actions of upper discharged from the overflow tube, heavy particles thrown to the wall of the barrel, slide along the barrel wall, from bottom outlet.

Materials ofd Hydraucyclone for desander desitler

Polyurethane is also called polyurethane formate, is a kind of polymer between the plastic and the rubber polymer materials. It has not only high strength plastic, and has the high elasticity of rubber. It is a new type of wear resistant material, an excellent comprehensive performance. It has many excellent performance, high wear resistance, in the synthetic material of the first, even more than some alloy steels. The polyurethane as hydrocyclone lining, its service life is four times of high chromium cast iron, four times eight times Ding hydrogen rubber, natural rubber. Polyurethane shore hardness in the range of 17~97 to 85~90, the best wear resistance.

Per different control system, there are fixed speed decanter centrifuge and variable speed control (VFD) decanter centrifuge.

Features of fixed speed control centrifuge

As the bowl speed and conveyer speed is fixed, cannot be changed, fixed speed control centrifuge is easy for operation and maintenance. And price lower compared with the same model VFD centrifuge.

Feature of variable speed control (VFD) decanter centrifuge

For the same model centrifuge decanter, VFD model cost more than fixed speed. Per International Explosion-proof standard, there should be positive pressured control panel for variable speed control for better cooling. It requests more professional on operators for the VFD decanter centrifuge.

For GN design VFD centrifuge, the bowl speed, conveyer speed and feeding pump flow are all flexible. Customer can change one or all of the 3 parameters to get the best separation performance in different jobsite. An and customer can change centrifuge parameter for getting the max. capacity centrifuge can reach.

Take GNLW363BG-VFD centrifuge for example, below steps show you how to find out the max. capacity of the centrifuge

1) For a bigger capacity, we should reduce the BOWL speed and increase CONVEYOR speed.



Pump running model set as AUTO

Then pump will running to the max. capacity it can reach.

2) Or you can try more settings to compare the capacity, with pump AUTO running:

a. Bowl 1600rpm, Conveyer 34rpm

b. Bowl 1800rpm, Conveyer 38rpm

3) The back drive motor is opposite rotating under low speed and high conveyer. If centrifuge shut down during running , reduce Conveyer speed.

4) For this centrifuge, the max. capacity will be not over 30cbm. As the pump max. capacity is 30cbm.

CBM drilling is the short name of Coal Bed methane. 95% of CBM drilling is getting nature gas. It is very different with oil and gas drilling. Oil and gas drilling rig normally need to drill very deep well to get crude oil, while CBM drilling is normally in small depth.  

As the special features of CBM drilling, it has higher standard for drilling fluids. High quality bentonite is widely be used for CBM drilling mud systems.

As the high request on environmental protection, zero discharge mud system for Coal Bed Methane drilling necessarily should be equipped.

GN international high standard Zero discharge mud system for CBM drilling

1) GN double deck shale shaker with 4×4 inch desilter cone.

It is the first stage and the third stage solids control process. The double deck shale shake combine the function of shale shaker and desilter.

2) Baby centrifuge GNLW223VFD with small PLC control for VFD. It is used as forth stage solids control.

3) Mixing hopper and mixing pump for mud mixing

The mud tank can be skid mounted, mobile mounted, or equipped with hydraulic jack up legs for self-lifting.  

GN Solids Control is world famous manufacturer for mud recycling system for HDD, CBM, piling, underground instruction, trenchless, dredge slurry separation, etc…
GN Solids Control also offers customized solution per customer’s condition. A customer request 500GPM mud system for HDD rig. Below are their requirements on equipment for the 500GPM mud system. GN Solids Control gives solution relatively to optimize the mud system for HDD rig:
1) Customer request on 500GPM mud tank dimension: Mud tank to same as 20 ft standard O.T. container.( Standard frame with container corners for transport on containers vessels and for quick lifting)
GN Solution on the 500GPM mud system tank dimension: It is no problem for exactly same dimension with 20ft container. But GN recommends the tank with a smaller width: 2000mm in order to put into container for shipment.
2) Tank compartment for the 500GPM mud system: Divide the 20 ft mud tank to three chambers – (1) Shale shaker chamber, (2) De-sander chamber, (3) Desilter chamber
GN confirms the 3 chamber of the 500gpm mud tank system
3) Customer request to install bigger shale shaker model GNZS594E with 616 GPM.
GN team confirms the big shaker for 500GPM mud system.
4) Furthermore, customer request install 2 Nos. of big power pump 6×5 centrifugal pump with 45 Kw motor.

And install big capacity mud cleaner (shaker + 2 nos. of de-sander + 12 Nos. of desilter) model GNZJ594E-2S12N with 1056 GPM capacity.
Per the big centrifugal pump and big capacity mud cleaner, GN engineer give solution that: connection shale shaker with mud cleaner shaker with distribution box, controlled by valve, customer can choose to use 1 shaker or 2 shakers. In this case, the mud system can extend to be with 500GPM capacity or 1000GPM capacity.
During 500GPM capacity, the user blocks half of desander cone and half of desilter cone for a better hydraucyclone separation.
5) Regarding mixing system, as customer already have some mud tanks locally, GN offers a separate jet mud mixer for option. Customer can chose it to match with its local mud mixing tank. Or connect the shale shaker tank with its original mud tanks.
The system is easy to shift between 500gpm and 1000gpm capacity. Customer is very happy with professional engineering team of GN Solids Control.
If you have interest on above 500 / 1000 GPM HDD mud system, or you have any special request on no-dig compact mud recycling system, you can contact GN group freely for more information.