Desander Desilter

Recently one batch of 18 inch decanter centrifuges and mud agitators are ready for shipment to Offshore drilling company.

The decanter centrifuge with 4 lifting pads which meets the lifting requirement of offshore drilling company. The centrifuge pulley protection cover is painted with safety mark. The main motor and back drive motor comply with ATEX explosion proof standard for offshore used. The 18 inch decanter centrifuge model number is GNLW453, the bowl diameter is 18inch (450mm), bowl length is 61 inch (1540mm), the typical treating capacity is 264gpm (60m3/h) for drilling fluids. The max bowl speed is 3200rpm, the typical bowl speed is up to 2800rpm, the max G force is 2578G, typical G force is 1973G, the main motor is 55KW, the back drive motor is 22KW. The recommend feeding pump motor is 15KW. The mechanical separation cut point is 2 ~5 microns.

Features of offshore used decanter centrifuge:
1) Compact structure, smaller footprint, lifting pad to meet offshore lifting standard
2) ATEX certified motor and control panel to meet offshore use
3) The screw is protected by tungsten carbide tiles for longer life and easy maintenance
4) The bowl is made of duplex stainless steel SS2304 by centrifugal casting
5) The solids discharge port and fluids distribution port is protected by tungsten carbide inserts for wear resistance.
The coupler type mud agitator consists of C face ATEX explosion proof motor, helical bevel heavy duty gearbox, coupler painted with yellow color, offshore standard skid, agitator shaft, impeller, stabilizer. It is suitable for oil based mud , water based mud and synthetic based mud. Based on mud tank dimension, we will use different size impeller.

Except for coupling connection mud agitator, GN also produce direct connection mud agitator with helical bevel type gearbox, We can provide different models mud agitators for your different applications.

A zero discharge system consists of three or four linear motion shale shakers to treat mud to separate the cuttings from drilling fluids. The drilling cuttings are discharged from shale shaker, desander, desilter, decanter centrifuge to a screw conveyor to transfer the cuttings to vertical cuttings dryer ( oil based drilling cuttings) or high G drying shaker ( water based drilling cuttings).

The vertical cuttings dryer is used to recover the oil from drilling cuttings. The discharged solids with oil content below 5% will be collected by screw conveyor for disposal or landfill directly or be sent to Thermal desorption unit for further heating and reduce the oil content to meet the environmental protection regulation.
The recovered oil fluids will be collected by fluids holding tank. One submersible slurry pump or progressive displacement pump transfer the fluids to decanter centrifuge to separate the colloidal particle solids from the drilling fluids. The fluids is returned to the solids control system by a transfer pump.

The water based drilling cuttings are treated by high G drying shaker through shaker screens, the discharged solids together with the solids discharged from decanter centrifuge are collected by screw conveyor and transfer to cuttings solidification unit, to mix with lime and absorber, the solidification of waste allowed the transportation and disposal of the solids without secondary containment, and converts hydrologic sensitive liquid and semi-liquids waste in a physical form which can be storage safely.
During the whole processing, the drilling waste treatment is in a closed loop without requiring dig a waste pit. Zero discharge system including shale shaker, desander, desilter, mud cleaner, centrifugal pump, decanter centrifuge, high G drying shaker, vertical cuttings dryer, waste centrifuge and feeding pump, screw conveyor, etc. If you need a zero discharge system for drilling rig, pls contact with GN solids control.

An integrated solids control system might include scalping shakers, linear motion shale shakers, desander , desilter, vacuum degasser, decanter centrifuge, mud agitators, mud gun, mixing hopper, centrifugal pump, which are installed on the mud tank system.

The solids bigger than 100 microns are removed by primary shale shaker, solids bigger than 45 microns are removed by desander, solids bigger than 25 microns are removed by desilter/ mud cleaner, solids bigger than 10 microns are removed by decanter centrifuge. The low gravity solids are separated by high speed decanter centrifuge, the high gravity solids are separated by middle speed decanter centrifuge. The drilling cuttings will be collected by cuttings collection box or screw conveyor, and then transfer the drilling cuttings to drilling waste management system.
Water based drilling cuttings treatment system consists of high G drying shaker and VFD decanter centrifuge with chemical dosing unit, the water can be sent to waste water treatment facility for final disposal or add additive to prepare for new drilling fluids.

Oil based drilling cuttings treatment system including vertical cuttings dryer, VFD decanter centrifuge, the recovered drilling fluids will be pumped back to solids control system for reuse.
The linear motion shale shaker will be installed on the shaker tank with drilling fluids distribution box which will receive the drilling fluids from flowline and flow to each shale shaker evenly for better separation. The shaker screen installed on the shale shaker is composite material frame shaker screen which is produced comply with API RP13C standard. We can produce shaker screens from API 20 to API 325 as per client’s requirement, the mud engineer can control the mud weight to use different API mesh screen.
GN solids control can design and produce the integrated solids control system for their drilling rig, for more information of our equipments, pls contact with us freely.

The solids vacuum pump is mainly used for drilling cuttings transfer, mud tank cleaning, drilling rig platform cleaning, waste pit cleaning, etc. applications by oil service company and drilling companies.

GN solids control have different model vacuum pumps for option based on their requirement. GNSP-40B max capacity is 40m3/h, GNSP-20B max capacity is 20m3/h, GNSP-10B max capacity is 10m3/h. The design capacity of the vacuum pump is nominal capacity, it will varied based on different material, suction and discharge distance and depth. The air supply should be sufficient for vacuum pump reliable operation. The drilling waste can be picked up automatically and transferred to drilling waste management system. Another method to transfer drilling cuttings is screw conveyor, due to place limit and rig site layout, the screw conveyor system may not be used, then solids vacuum pump can be used instead.
The suction process is that the air compressor provide the air into the vacuum generator, which produces negative pressure in the pump body and suck the drilling waste from the suction pipe. The discharge valve is in close condition. According to suction time, the pump will suck material automatically.
The discharge process is that close the valve of vacuum generator, the air flow to the pump body to produce positive pressure inside the pump body. The discharge valve is open, and the drilling waste is pushed out by positive pressure to the expected area.
The features of GN vacuum pump:

1. It can be used for hazardous area application, since it is 100% air operation pump. But air compressor is required for air supply.
2. The suction horizontal distance is up to 50m, the discharge horizontal distance is up to 500 ~ 1000m.
3. The solids size allowed to enter into vacuum pump is up to 50mm or 75mm, the solids content is up to 80%.

As an oil sludge treatment system supplier in China, GN solids control also provide customized oily soil treatment solution. Recently one set of customized Oil Contaminated Soil Washing and Separation system are ready for shipment to our customer. Before feeding to standard oil sludge treatment system, we need to broke the solids into small pieces and mining separation shaker to screen the coarse solids and wash the solids so that the oil sludge became fluidity for easy separation by the oil sludge treatment system.

The crushed solids can be transferred by solids vacuum pump and be diluted in the pre-mixing tank and adding proper chemicals, agitating and mixing, the oil sludge will be transferred to screening module by submersible slurry pump. The solids vacuum pump is 100% air operated pump which needs an air compressor to supply air, it can be operated with automatic mode or manual mode according to their requirement.

There is an separate chemical dosing module to add chemicals in the pre-mixing tank and feed the chemicals to decanter centrifuge and 3 phase disc separator, the automatic chemical preparation and dosing unit is used in the preparation, storage, and dosing of powder chemicals. The single barrel manual dosing system is commonly used for manual injection of chemicals, which has the basic function of continuous and stable dosing. Both of the barrel dosing system and automatic chemical dosing unit are installed inside the container for reliable operation and for sun/rain proof.

The main separation components is the centrifuge separation module, including solids liquid separation decanter centrifuge, 3 phase separation disc separator for oil and water separation. The recovered oil is collected into buffer oil tank, the treated water is stocked into water tank, which can be used in the circulation system. The discharged solids will be collected by waste container for further treatment or final disposal.

One set of customized mud tank system is ready for shipment to Middle East. The ATEX certified motor and electric control system can be applied for offshore drilling rig solids control system. The mud tank system is composed of 1 ea shaker tank, 2 ea storage tank, 1 ea water tank, 1ea of pump skid and 1 set of electric control system.

The main equipments of shaker tank including 3 sets of linear motion shale shaker and 1 set of hydrocyclone assembly, 2 sets of mud agitator, 4 sets of mud gun. The linear motion shale shaker is a 4 panel screen shale shaker with 585x1165mm shaker screen. We can produce different API from API 20 to API 325 as per client’s requirement. The drilling fluids from well head flow to fluids distribution box and evenly flow to shale shaker for primary solids separation, the desander cone and desilter cone assembly installed on top of the 3rd shale shaker as the 2nd phase separation and 3rd phase separation equipments, the feeding pump are installed on the pump skid, and the suction and discharge pipeline are connected. The standard mud cleaner with compact footprint is without buffer box, when it is used as back up shale shaker, an extra buffer box will be added, and the hydrocyclone assembly frame will be installed on top of the shale shaker.

The 2ea mixing hopper , 2ea mixing pump, 2 ea centrifugal pump and a special designed collection hopper will be installed on a skid, the mixing pump can be also used as transfer pump, for longer working life, the pump housing and impeller are made of hard ductile iron alloy for better abrasion resistant capability, the mechanical seal to provide zero leakage and longer operation life. For more details, pls contact with GN solids control.

Mud agitator is drilling mud agitating and mixing equipment of solids control system. All the mud tank compartments except for sander trap should be agitated to avoid solids deposition at the tank bottom and maintain a consistent mixture throughout the surface system. The mud agitator use an electric motor to drive single or double impeller blades which flow the mud in a pattern throughout the mud tank. The mud agitator prevents settling enhances the efficiency of solids removal equipmnets, such as shale shaker, desander, desilter, decanter centrifuge, degasser, etc.

According to the mud weight, mud tank dimension, mud tank design ( round or square), mud agitator qty, desired turnover ratio ,the user will select proper size impeller, agitator qty, motor and even impeller qty ( single layer or double layer). If the agitator model and qty is not proper used, it will lead overheating and over current and lead over torque to damage the mud agitator. The main components of the mud agitator including electric motor ,gearbox, mounting plate, agitator shaft, impeller, and stabilizer, there are direct connection and coupler connection based on different requirement. Based on different type gearbox, there are helical bevel type gearbox and worm wheel type gearbox. Based on mud tank dimension and remained room, there are horizontal type mud agitator or vertical mud agitator. Based on different ambient temperature, the required gear oil is different. If the gearbox oil temperature exceeds the upper limit or the motor temperature exceed 95℃, and there is vibration and abnormal noise, the user should stop the agitator immediately for inspection.

GN produced mud agitator utilized heavy duty helical bevel gearbox, direct connection, horizontally installed, which is with compact size, reliable operation, low noise, good mixing performance, the explosion proof motor can be CNEX, ATEX or IEC EX standard to meet different explosion proof standard.

As a manufacturer of solids removal unit in China, GN produced solids control/ removal unit has been widely used for mineral engineering projects. More and more clients start to realize that the solids removal unit’s usage will take a lot of advantages to the users.

1. The Solids removal unit will reduce the water consumption and reduce the drilling cost significantly
2. The solids removal unit will reduce the wear on drill components and protect the drilling rig, it will extend the drilling rig service life effectively
3. The solids removal unit can reduce the drilling waste and lower the waste disposal cost and environmental management cost
   Anyway the investment on the solids removal unit will be another consideration compared with the direct cost savings and potential cost savings, it is not easy to clear the potential cost savings. The client may select to rent the solids removal unit for a short term project, for a long term mineral projects, to buy a solids removal unit is an economic way.
4. 
   GN Solids Removal Unit including fluids picking up pump ( it will be installed in the mud pit vertically to pick up drilling fluids from mud pit to shale shaker), shale shaker( to removal coarse solids and reduce solids content to let the drilling fluids suitable to be treated by decanter centrifugue), decanter centrifuge ( mechanical separation cut point is 5 microns) and feeding pump, mixing hopper, mixing pump and mud tank. The clean fluids treated by decanter centrifuge will be mixed with chemicals and pump back to drilling rig. The electric control system can control all the motors and starter of all the equipments. A generator can be installed on the solids removal unit skid as power supply.
   For more information of the solids removal unit, pls contact with GN solids engineer.

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.