centrifuge

Two weeks ago, GN Solids Control completed one set 40 feet water based drilling waste treatment system that is used for oilfield waste management service. Water based drilling waste is coming from the drilling projects where
use the water based drilling fluids to cool down the drill bit, protect the drilling well wall and take out the drilling cuttings.

The main equipment included in this 40 feet water based drilling waste treatment system are as follows:

1) High G force dryer shakers used to further drying the cuttings discharged from the primary solids control equipment, wide open deck design allows the feeding of waste easily
2) Dosing System for mixing chemicals that will fed to the centrifuge for flocculation process
3) High speed Decanter Centrifuge for liquid and solids separation
4) Mud Tank unit under the shaker to collect the liquid going through the shaker screens
5) Screw Pump transfer the fluids to decanter centrifuge for polishing

water-base-drilling-waste-management-system-2

Drilling Waste Management System

Working diagram of the 40 feet water based drilling waste management system

The drilling waste, always coarse drilling cuttings, was fed to dryer shaker for further drying, and then the screw pump will transfer the drilling fluids with ultra fine solids to the decanter centrifuge (It is also dewatering centrifuge). In the meanwhile, the chemical dosing system mixes polymer, once the polymer solution is cured. The diaphragm pump transfers the polymer to the dewatering centrifuge. The ultra fine solids will get together once meet with the polymer, which will help the centrifuge to separate the solids. The drilling waste management system for separating the ultra solids in waster based drilling fluids is also called dewatering system.

Equipment features of the 40 feet water based drilling waste management system

GN’s high G force dryer shaker has up to 8 G force. with 4 panels composite material screen, the Dryer shaker has an excellent separation and drying performance.
GN high speed decanter centrifuge and feeding screw pump are VFD driven and controlled by PLC. The operators could set the suitable parameters to treat different kinds of drilling fluids.
Besides the drilling waste management system for water based mud, GN also developed the equipment for oil based mud. Even the oily sludge treatment solution is one of GN’s main businesses. GN’s system for drilling waste management has many performance cases that will prove GN equipment quality and availability. This is why customers choose GN Solids Control.

GN now is gradually known as a separation solution provider who not only has the business to provide equipment for drilling cuttings separation from drilling fluids, but also for recovery the oil in the oily sludge. After couple years research, GN developed a 4 stages separation system that could effectively recover the oil from the oily sludge coming from oil based drilling waste, refineries waste and crude oil tank cleaning slurry.
To be frank, GN’s 4-stage oily sludge treatment system is consisting of 4 modules. These 4 modules could be combined freely as per different sludge conditions or outputs. Now let’s see what is the 4-stage oil sludge treatment system.

gn-waste-oil-recovery-system

Waste Oil Recovery System

The first stage is the high G force drying shaker with washing tank. The high G force drying shaker is located on a slurry tank. With a hopper type feeder, the oily sludge could be fed to the shaker easily. Up to 8 G force could effectively remove the coarse material in the sludge. The shaker unit could be equipped with hot water spraying system for better demulsification. To prevent the oily sludge spraying out of the shaker deck, this shaker will have a top cover.

GN was founded as a manufacturer of solids control equipment that used in drilling industry. Drilling fluids was used to lubricate and cool down the drill bit, and it can also bring out the drilling cutting from inside of the drilling hole. The working principle of solids control equipment is to remove the solid phase from liquid phase by various methods, mostly using screen technology and centrifugal separation. Thus the solids control equipment are more and more used in some other industries where need separate the solid from liquid.

mining-ore-washing-water-treatment

Gravel Washing Water

High pressure water for mining is one of the industries that can use the solids control equipment to increase the working efficiency. The mining worker will use the high pressure water gun to flush the mineral ore, thus the mixture of ore, silt and water will collected in a pit. High pressure washing will reduce the silt content on the ore, thus the more pure ore could be obtained.
Ore and water slurry would be firstly fed to a coarse shaker for large size solid particles separation. Then de- sander and de-silter would be used for much finer solids separation. The extreme fine ore particles may use decanter centrifuge to separate. Decanter centrifuge is an ideal choice for slurry separation, as the centrifuge is working by centrifugal force, water, silt and ore particles have different specific gravity, which would make the separation much easier.
The worker will get different ore from each stage of solids control equipment. The more important is large volume water is recovered. This greatly reduces the consumption of water. The recovered water could be used again and again.
Nowadays, GN solids control is not only a manufacturer of solids control equipment, but also a separation solution provider. For a example, GN developed the centrifuge for food and beverage industry.

Most of the horizontal directional drilling mud system is not equipped with decanter centrifuge unit as by using the 3-phase separation system including shale shaker, de-sander and de-silter unit, it can work good enough for removing the solids from drilling fluids. Centrifuge is relative high cost, which is also a reason the drilling contractor doesn’t equip it in the mud system.

gn compact centrifuge system

GN Centrifuge System

However, for some high request drilling condition, the driller may use the heavy mud for better drilling performance. Sometimes the drillers add the certain chemicals to make the drilling mud heavier so that the mud can better protect the wall of the drilling hole. If the driller went to drill another well, the heavy chemicals need to be separated, and then the centrifuge could be used to do this job. In some other conditions, after many times recycling of the drilling mud, there is much ultra fine solid particles that cannot be removed by the shaker and cyclone unit, and then the centrifuge unit is needed.
GN Solids Control has nearly 10 years in fabricating the drilling mud system for HDD projects. This type mud system need to be compact structure and easy for transportation. See the picture in this article, both the de-sander and de-silter unit are equipped with under flow shaker for drying the discharged solids. The shakers used are 2-layer screen design. The bottom layer screen is used as primary shaker and upper layer screen to dry the discharges out from the cyclone units. This design greatly reduces the footprint of the mud system. And all tank top surface equipment are pre-installed on a frame with same base dimension as storage tank. When transport the mud system, the shaker and decanter centrifuge units could be removed by lifting the frame for fast disassemble. With the frame, the equipment could be easily transported by flat bed trailer.
GN can provide both standard and customized HDD mud system for clients. Just send us your request, and then you will get a satisfying and cost effective solution.

In drilling mud solids control system, pumps are used to transfer the drilling fluids from one machine to another. Submersible slurry pump is one type pump installed vertically on mud tank or mud pit. In GN designed solids control system, this type slurry pump is often used in HDD project and feeding to centrifuge wherever it is used.

hdd mud system

hdd mud system

Submersible pump used in HDD mud system

GN has standard model of HDD mud system ranging from 200GPM to 1500GPM. All the models are compact structure. The used drilling fluid in this horizontal drilling comes out from the drilling hole and accumulates in a mud pit. It requests a pump to transfer the drilling mud to the mud system. Above picture perfectly shows the how the submersible slurry pump is installed vertically on the mud pit to transfer the drilling mud to the shale shaker in the HDD mud system. As this pump is installed out of the mud system, when making the quote to clients, GN always recommends an independent submersible slurry pump as an option.

submersible slurry pump

slurry pump

Submersible pump used as centrifuge feeding pump

In an oil and gas drilling mud system, after treated by the de-silter cyclone, the drilling mud will be pumped to decanter centrifuge for fine solids separation. Vertically installed in mud tank will ensure a larger tank compartment capacity for more drilling mud storage.
GN’s submersible slurry pump is single stage single suction type pump that is usually used to transfer the slurry with larger solids content. There is no bearing and gland seal between impeller and pump body; hence the slurry pump is maintenance-free and high temperature resistance. Submersible slurry pump is an ideal equipment to transfer the mud to centrifuge and HDD shale shaker. Besides, it can also be used to feed the de-sander and de-silter.

All persons who ever been a drilling site will know that the solids control equipment like shale shakers are located on top of the mud tank. The shakers are fixed directly by bolts onto the mud tank top, if you want disassemble the system, you need loose the bolt and take off all the shakers units one by one which will cost much time.
GN Solids Control ever made several mud systems in which the primary solids control equipment are pre-installed on a framework, and then the framework whole package is put on the mud tank top. Just like below picture shows 2 unit GN’s double layers shale shakers in installed in a 20 ft container size framework, under the shaker base and on the frame skid, there are opening through where the drilling fluids could flow down to the mud tank.

20160217 gn frame installed shale shaker

GN Shakers Pre-installed in Framework

What benefit this design would brought to the operator
1. Preinstalled shakers on the frame greatly save the time for assembling and disassembling, not bolt will be lost during the procedure of many times installation.
2. Container sized frame with container fixing point at all 8 corners of the bottom skid and top beam. This frame could be put directly on the flat bed trailer for easy transportation.
3. The horizontal and vertical beams and legs could be used as support of rain cloth to cover outside the frame for bed weather.
Actually, not only shale shakers could be pre-installed in this type framework, the decanter centrifuge unit can also be put in it. On the frame, there will be enough space for wire cables laying.

Framework is simple but it could bring convenience to operators. Besides this type frame, GN could also provide telescopic skid frame used to put decanter centrifuge and vertical cuttings dryer on that for waste cuttings management application. That type frame is little complex, however, it could make the equipment a modular package to meet customers’ requirements better.

The drilling operator might know that after several times reuse of the drilling mud, there will accumulate more and more ultra fine solids in the mud that cannot be separated out with physical method even by using high speed decanter centrifuge unit.
The accumulated solids will rise up the mud specific gravity that will greatly affect the mud performance. While, in order to keep the normal density of the mud, under this circumstance, the flocculation no doubt is the most popular method to be used.

polymer mixing unit (1)

polymer mixing unit

The flocculation process is produced in a type of machine called polymer mixing unit. This unit is used to mix the polymer that will be fed into the centrifuge to gather the fine solids in the mud. This polymer mixing unit is always connected with the centrifuge unit in the solids control system. After the separation by primary solids control equipment like shale shaker and cyclone unit, most of the solids larger than 5 microns could be removed out. The centrifuge unit plays an important role in this flocculation process. Sometimes, this centrifuge is called dewatering centrifuge.
GN’s polymer mixing unit is designed as 3 compartments mixing tank with automatic dosing conveyor and agitating device. Dry chemicals and water are fed into the first compartment for mixing, and then overflow into the second compartment for maturing process. The third compartment is used to store the solutions waiting for use.

polymer mixing unit (2)

dewatering centrifuge

The material of this machine body is PP. At each compartment, there is installed one automatic agitator with stainless steel made agitating shaft and impeller. The chemicals feed hopper is also made of SS304.

In order to realize the continuously mixing, the tank compartments are installed with liquid level control device. The mixing, maturing and storing process continuously transfer with low labor cost. The PLC design makes the operator adjust the solution concentration as per request, high automatic degree, and no need human watch over.
GN could provide the polymer mixing unit with dewatering centrifuge containerized for weather proof. For more information, welcome click to see GN Dewatering System.

GN Solids Control LTD and GN Solids America LLC’s VFD (variable speed drive) decanter centrifuge it allows oil well drilling service contractors or drilling mud service contractor company to perform the barite recovery, fine/ ultra fine solids filtrations and water-removal centrifuge. GN Solids Control LTD has the decanter centrifuge from 9 inch bowl to 22 inch bowl available for different solids-removal applications. GN Solid Control’s decanter centrifuge bowl length and diameter ratio is over 3 times and it gives the best result for the drilling fluids cleaning.

GN Solids Control China

Purposely to make drilling fluid decanter centrifuge parameter to perform adjustment according to the drilling stratum, depth of the oil well and drilling technology evolved through times, the development of the variable-control  speed and the closed-looped solids control system which basic on the main electric current to be as sending the control signal.

The oil-field application shows that drilling fluid decanter centrifuge matched frequency control speed closed-loop control system can use the different drilling fluid viscosity and density according to technology used and oil field’s physical condition.

Using decanter centrifuge main electric current signal, it automatic adjust the feeding pump displacement and high speed centrifuge actual parameter to realize drilling fluid centrifuge closed-loop control, ensure the de-slugging quantity and decanter centrifuge handing capacity always be in the condition at the fullest.

Drilling fluid decanter centrifuge frequency control closed-loop control system parameter can be automatic adjustment and realize self-awareness, also can efficiency avoid decanter centrifuge overload the fluid feeding and blocking.  It can improve the reliability of centrifuge operation; reduce the uncertain operation surprise because of sudden failure.

By using frequency control speed closed-loop centrifuge can automatic and manual adjust decanter centrifuge’s rotary speed, make it can be as the middle speed centrifuge(1000-2000 rpm), also can as the high speed centrifuge( 2000-3000 rpm) to achieve efficiency control drilling fluid solid phase content and improve drilling fluid solid control condition.

 

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Few months before, GN got order of 4 pieces decanter centrifuges from one Africa drilling company, after the jobsite actual operation, they placed the repeated order of 6 pieces decanter centrifuge. Many of the GN’s customers are this kind of old customers. A certain percentage of GN’s business is coming from the old customer who is satisfied with GN’s equipment performance.

This total 10 Sets decanter centrifuge are all package provided with the feed pumps. While for the centrifuge, there are both the fixed speed model of GNLW363BG and the variable speed model of GNLW363BG-VFD. The feeding pump is provided as a package solution for the customer; it is also an option for the customer.

GN Decanter Centrifuge

GN Decanter Centrifuge to Africa Drilling Company

The parameters of the centrifuges and feeding pumps are as below:

GN’s fixed speed centrifuge is designed typical speed of 3200 RPM, while maximum speed is 3900RPM. And there are different belt pulley for option and could also be package provided, the belt pulley are 2500RPM and 2200 RPM. The variable speed model could be adjusted from 0 to 3200 RPM. GN’s 363 series decanter centrifuge is designed bowl diameter of 14 inch and bowl length 50 inch which is very popular used in the drilling mud solids control and waste cuttings proposal processing. The treating capacity of 130 GPM could meet the general application demand on site.

GN always recommends the feeding pump for the provided centrifuge. The pump proposed is positive displacement type screw pump. The main material of the pump is stainless steel of SS316L that make sure a long life time and better feeding performance. The gearbox used for this pump is from Germany Nord. The capacity of 30 cubic meters per hour is matched to the treating capacity of the centrifuge.

GN’s decanter centrifuges are more and more used in the jobsite of drilling company worldwide. It is the stable performance won the customers trust and got the repeated orders for GN Solids Control.

GN solids control is the first one China based API certified manufacturer for drilling fluids processing decanter centrifuge. To meet customers’ requirement from different industries for different purpose, by now, GN has released a relative complete series centrifuges which have been proved good performance on site.

GN high speed centrifuge

GN High Speed Centrifuge on Site

This article is to give a brief introduction on how to choose GN’s decanter centrifuge according to different purpose. GN now has models of GNLW363 fixed speed and VFD, GNLW452 fixed speed and GNLW453 VFD, GNLW553 VFD.

1. For barite recovery, GN always recommends the model of GNLW452 with RPM 1800, designed maximum RPM is 2200. This is the lowest RPM model GN hold. GN also has the model GNLW363 with RPM 2200.
2. For general drilling mud solids control, the model of GNLW452 is proposed for high gravity solids separation. The customer could also choose the model of GNLW 363 with RPM 2700. If the customer has a cuttings dryer in the system, then GN firmly propose latter model.
3. For solids separation application to the low solids content drilling mud or the low gravity solids. It always is difficult to separate the solids thoroughly, then a centrifuge with high centrifugal force would be need. High speed centrifuge always has large centrifugal force could perform well for this application. GN always recommends the model of GNLW363 with RPM 3200.
4. For some of the mud recycling system, the operators always choose 2-centrifuge system for solids separation. One middle speed and then one high speed. For this application, GN’s solution is 1 unit GNLW452 with speed of 1800 and 1 unit GNLW363 with RPM 2700 or 3200.
5. GN could also provide centrifuge unit with several belt pulleys for different speed, the customer could adjust the RPM by changing the belt pulley.
The best solution for all this different working condition is to get a VFD model with different RPM in same unit centrifuge. GN could provide VFD model for 14”, 18” and 22” bowl with different capacity.

The above mentioned large size decanter centrifuge are all used for oil gas industry. GN also has a model of GNLW223 with capacity 6 cubic meters which is a very popular model for core drilling. This model is both fixed speed and variable speed available.
Any questions, you may contact with GN or send Email to us for more information.