Oil Sludge processing system

In April, a full set of drilling cuttings washing system is ready for commissioning for a China client at client’s job site. The drilling cuttings washing system is used to wash and separate oil base drilling cuttings and oil sludge generated from oil and gas drilling, and refinery.

There are 7 treatment modular in this drill cuttings treatment washing system:
1.Pre-treatment: A set of coarse shale shaker is used in this modular for crushing the big rocks and for pre-seperation. It is the pre-treatment before all separation steps.
2.Screening separation modular. There is a high G drying shale shaker used in this step to remove the big size particles.
3.Washing modular with static mixing for mixing and preparing solids and liquid mixture. After that, the liquid mixture can be separated by next step separation equipment.
4.Liquid and Solids separation modular with decanter centrifuge for 2-phase separation. It is the 1st time liquid and solids separation.
5.The 2nd time washing modular with dewatering treatment to remove the fine solids in the liquid.
6.The 2nd time 2-phase decanter centrifuge separation unit for ultra fine solids separation.
7.The liquid recovery modular.

It is a a full function oil based drilling cuttings washing and separation system with a full set of separation and treatment equipment. Below list is the major treatment equipment used in this oil based drill cuttings washing system:
1.A Drum shale shaker is used in the pre-treatment unit to crush the big rocks and remove it.
2.A high G drying shale shaker is used in the screening separation modular to remove the big size particles. It is the most hot sale shaker model GNZS594F which is widely used in oil and gas drilling solids control systems.
3.2 sets of static mixing unit are used in the 2 stage washing modular.
4.A inclined plate clarify is used for soil settle down in the oily liquid, which is discharged from decanter centrifuges.
5.Screw conveyor and belt drive conveyor are used in the system to feed for shaker and for solids discharge from decanter centrifuges and shale shakers.

As the oil sludge treatment is a new trend. It means a new business scope for many companies. Many clients do not have much experience before they run GN waste management plant.

In order to ensure they have enough knowledge to operate the unit and reach good performance, GN Solids Control will send engineer to job site to help for the first time commissioning. GN engineer will support to test the treatment unit with real oil sludge and to train their stuff about how to adjust the system based on the material situation in order to reach a good performance. And GN engineer will give training about normal maintenance and trouble shooting if requested by clients.

Recently, GN Solids Control engineers just finished the commissioning job of an oil sludge treatment plant. The treatment plant is for a China domestic client which is used in China. It is a middle size oil sludge treatment system with 14inch centrifuges to treat oil contaminated wastes. And it is also the most popular size oil sludge treatment plant.

It is a complete oil sludge treatment plant for 2-phase and 3-phase separation. Below is the major separation plant of the oil sludge treatment plant for this project:

1) The 1st modular of the oil sludge treatment plant is premixing and heating tank package. The solids and liquid inside the raw oil sludge is not equal. Or some time, the solids control is too much high. The first stage is to prepare the sludge and make it suitable for separation. The processes which maybe be used in this stage are: mixing, dilution, heating, chemical dosing. Clients and chose 1 or more process based on the material situation.

2) The 2nd modular is drying shaker tank unit for coarse separation. The drying shaker is customized with rubber sealing cover and steam nozzle pipelines for heating. Clients choose the right API shaker screen to remove particles above a certain sizes.

3) The 3rd modular is decanter centrifuge C/W a holding tank for 2-phase separation.

4) The 4th modular is 3-phase centrifuge C/W holding tanks

5) The 5th modular is containerized dosing system to supply chemicals for the whole treatment process.

Oil and gas drilling, refinery, and crude oil production will all generate a large number of oil sludge waste.The oil sludge waste generated from drilling, refinery and crude oil production have complex composition, which may cause serious pollution to the surrounding environment and wasted resources. As this reasons, it is essential and necessary to treat the oil sludge waste, to reduce and minimize the waste in order to protect our environment.

GN Solids Control utilizes heating washing technology with chemical enhancing system to treat the oil sludge from oil and gas drilling and refineries. 2-phase / 3-phase decanter centrifuge and 2-phase / 3-phase disc centrifuge are used in GN oil sludge treatment system.  The major function of GN oil sludge treatment system is to reduce the solids and liquid waste volume before enter into superior processing equipment.

The water recovered from GN oil sludge system can be reused in the separation system, or use the water for injection. But the water cannot be discharged into environment. They need further slurry separation treatment before discharge. The recovered oil can be sold to refinery companies. The solids can be used as construction field material, like to to make bricks for road construction.

With suitable chemical dosing, below is the major parameters of soil, oil and water after separation from GN oil sludge separation system:

The Oil on Solids Discharged from Decanter Centrifuge is around 1-3%. The solids waste volume is greatly reduced, clients can send the solids waste to TDU company to treat. The cost will be much lower than you buy a TDU. As the cost of TDU and its operation cost is greatly high. Besides TUD, the clients can also use Biodegradation technology to further reduce OOC to 0.5% or less.

Recovery Oil from 3 phase centrifuge BS&W is around 2-3%. Clients can sell it to refinery company.

Oil Content in recovery water from 3 phase centrifuge is 1000-3000PPM. The recovered water can be reused for premixing tank inside the treatment system.
You can add a Water Treatment system to reach 50-100PPM (Oil Content, Water after treatment unit). Or you send the water to slurry treatment company to treat for you.

Oil sludge treatment, oil base mud and drill cuttings treatment is the major product made by GN Solids Control. Some clients do not know the difference of Oil sludge treatment system and oil base cuttings treatment system. They want to know the difference and know how to choose the right separation equipment.

Normally for OBM cuttings treatment, clients will separate cuttings and recover usable drilling fluids, and sell the drilling fluids. It is 2-phase separation. While for oil sludge treatment, clients will separate oil, water and solids. They do 3-phase separation.

Below are some general information to let clients know more about the different and about the equipment choosing.

1) As 3-phase centrifuge can only allow slurry with max. 10% solids content and particle size less than 2mm, 2-phase decanter centrifuge is must to be used before 3-phase separation to reduce the mud weight and solids percentage. After 2-phase centrifuge separation, the oil, water and soil mixture slurry flow into 3-phase decanter centrifuge to get oil, water and soil.

2) In order to remove as more ultra fine solids as possible, chemical dosing unit will be used together with decanter centrifuges for dewantering flocculation treatment. We quote you the 3-tank antomatic chemical dosing unit. It is used for powder chemicals. If you will use liquid chemical, pls tell me to revise the quotation.

3) Per our communication on Whatsapp. The pre-separation equipment for OBM cuttings and oil sludge is different. For pure OBM cuttings from shale shaker and mud cleaner, Vertical cuttings dryer is better. It can reduce the oil on the cuttings to 3% ~ 5%. It can remove more usable liquid. And the solids discharge is very dry.

But vertical cuttings dryer cannot be used to treat the soil sludge discharged from centrifuge. As its screen basket opening is 0.5mm, 0.35mm and min. 0.25mm. The soil cake from centrifuge is very fine and will all pass the screen opening.

4) Oil sludge is normally the mixture from different application, like drilling mud, drilling cuttings, soil cake from centrifuge separation, tank bottom slurry, slope oil, refinery waste oil slurry, industry waste oil, etc… The solids size and solids content is more complex. In this case, high G drying shaker is used for pre-seperation. And as the oil slurry is more complex, sometime, need to dilute and heating the sludge before separation. The solids waste discharge from High G drying shaker is with higher oil on the cuttings after separation. For example, before treatment the sludge with 15~20% oil content. After high G drying shaker, maybe around 10~15%, or even higher if the sludge with high viscosity and density.

GN Solids Control has an oil sludge treatment system which is used at Qinghai Oilfield in China. The system is used since May 2018 till now. It is a customized oil sludge waste reduction system. Clients are happy with its performance.

Many clients are showed great interest on the system, below is some information of the system to let people know more.

1.The system is used since May 2018 till now, the location is Qinghai Oilfield in China.

2.The liquid content of the raw material oil sludge is 70% – 80%.

3.There is a pre-mixing and heating modular in the oil sludge separation system. Oil sludge will be heated up to 60C degree, during the heating process, chemicals will be enhanced into the process procedure to help for separation. The chemical enhancing is based on the material situation. If the material is easy for separation, heating and chemical dosing may be not needed. It depends on the separation result.

4.There is a double deck drying shale shaker in the customized system for pre-separation. After shale shaker, there is a desander separator.

5.After desander mud cleaner, it is decanter centrifuge separation by an 18inch big bowl centrifuge. There are 2 sets GNLW453C-VFD centrifuge for ultra fine solids separation.

6.There are 2 types of sludge vacuum pump for sludge and slurry transfer in the system: GNSP20B and GNSP40B.

7.The system for the client is 2-phase separation. After separation, clients get clean oil slurry with small percentage ultra fine soil. The oil slurry recovered from GN oil sludge system will be further treated by slurry separation system to get oil and water. The final solid waste is taken to third party the biodegradation and pyrolysis company for processing.

GN Solids Control can also offer 3 phase separation after the 2 phase centrifuge sepration to get clean oil, water and solids.

Big bowl decanter centrifuge is a major separation equipment for oil sludge treatment. GN Solids Control makes 2-phase decanter centrifuge for liquid and solids separation, and 3-phase decanter centrifuge for water, oil and solids separation. The centrifuge bowl sizes are vary from mini size 9 inch to big bowl 22 inch size and the largest big bowl 30 inch.

Last week, some sets of GNLW554ET- VFD decanter centrifuge were shipped to an clients doing oil sludge treatment. GN Solids Control makes T Series Decanter Centrifuge mainly for dewatering treatment and for thickness.

GN T series decanter centrifuge for dewatering / Thickening is with beach angle of 8.5 degree. It is widely used for maximum dewatering requirements of municipal and industrial waste water sludge. The dewatering decanter centrifuge is designed for easy separation material include large particle size, high density difference of solid and liquid, low viscosity, high concentration, high treatment capacity and higher dryness than clarity. The materials like sludge or wastewater containing fine particles usually need to be added with flocculants to gather the fine particles condensed into large ones, and then dewatered with T series decanter centrifuge.

Applicable Material of GN Solids Control T Series Decanter Centrifuge can be used to treat below materials, but not only limited to them: Drilling mud, environmental protection sewage, oily sludge, cutting fluid, sand washing water, mineral washing water, soda white mud, salt mud dewatering, magnesium aluminum emulsion, steel-making waste water, precision casting waste water, construction mud, tunnel mud, mine waste water, industrial waste water, organic waste water, aquaculture waste water, chemical industrial waste water, printing and dyeing waste water, municipal sewage, river sludge, water plant sludge, lake sludge, kaolin grading, calcium carbonate, bentonite, Silica, titanium dioxide, calcium sulfate, barium sulfate, conductive film glass polishing solution, aluminum hydroxide, cryolite, silicate, oil sand separation, landing oil, oil sludge, coal tar, inorganic fertilizer, Chinese medicine extraction such as taxus chinensis, honeysuckle and liquorice, clarification, concentration and dehydration of salt crystals, etc

The most popular bowl size used for oil sludge separation is 9 inch, 14 inch and 22 inch decanter centrifuge. For the 3 bowl sizes, GN Solids Control has 2 model series to suit for different material situation. The 2 model series are defined per the ratio of bowl length and bowl diameter. GNLW223, GNLW224, GNLW363, GNLW364, GNLW553, GNLW554.

Regarding the 3 bowl diameter 9 inch, 14 inch and 22 inch decanter centrifuge, the ratio of bowl length and bowl diameter can be 3 or 4. The ratio 3 serials decanter centrifuge can be used for oil and gas drilling fluids treatment. The ratio 4 decanter centrifuge is specially designed for oil sludge treatment and waste water, waste oil treatment.

GNSX-450 is a three phase decanter centrifuge. The bowl size of GNSX-450 three phase decanter centrifuge is 450mm (18 inch) diameter by 1800mm in length. It is designed for 24 hours continuous and smooth operation throughout the day. It is mainly composed of driving system, decanter bowl, and screw conveyor inside the bowl, cover box, skid and VFD control panel.

Working principle of GN Solids Control 3 phase decanter centrifuge

GN Solids Control 3 phase decanter centrifuge is mainly designed and made for liquid, liquid and solids separation. GN Solids Control 3 phase decanter centrifuge can also be applied to two immiscible liquids with different specific gravities. When the solids and liquid mixture (raw material before separation) rotates into the high-speed rotating bowl internal the 3 phase decanter centrifuge, the solids and liquid mixture rotates synchronously with the drum. As the reason of the different specific gravity, the centrifugal force of the solids and different liquid is different.

The solid particles which with the larger specific gravity are subjected to the greatest centrifugal force, followed by the heavy phase liquid (such as water) and the light phase liquid (such as oil). So the centrifugal force is becoming less from outside to inside according to the magnitude of centrifugal force. A concentric solid layer and two liquid layers are formed.

The Solids phase inside the mixture will be pushed out by the conveyor impeller of the centrifuge bowl, and liquids are removed from their respective nozzles depending on different gravities. As the reason, GN Solids Control three-phase decanter centrifuge can not only separate the solid from the solids and liquid mixture, but also separate the two-phase liquid with different specific gravity in the liquid and liquid mixture. In this case, Solid / liquid / liquid separation can be achieved.

Besides 3-phase decanter centrifuge for oil field and non-oil field, GN Solids Control has other separation equipment to cater for different application, like shale shaker, mud cleaner, desander, desilter, degasser, transfer pumps, drilling waste management equipment, etc…

GN Solids Control is specialized in drilling mud solids control and waste management solutions. GN Solids Control is capable to design and make Oil Water and Solids Separation System to treat and recover various kinds of waste materials.

GN Oil Water and Solids Separation Systems are capable to treat below waste materials, but not only limited to below materials:

1. It can be used to treat oil sludge and oil, oil contaminated soil remediation, like from drilling waste pits, or from pondsand tanks
2. It can be used for water oil contaminated water-control and recovery
3. It can be used to treat waste oil and recover the oil to reuse
4. It can also be used to treat waste oil, water and solids mixture, and to recover oil, water and reduce the solids waste

Oil sludge means the waste mixture consisting of oil, water and solids. Oil water separation system is used to treat the oil sludge in order to reduce waste material, and recover oil and water for reuse. The oil sludge treatment system is also a popular solution to treat oil contaminated soil and sands.

Oil sludge is a mixture consisting of oil, water and sands. The treatment on oil sludge would recover much oil and water for reuse. Also it is an ideal solution to for the solids disposal. More oil and water recovered, more energy and resource could be saved. GN oil sludge treatment products mainly include decanter centrifuge, oil water separators and thermal desorption unit.

As many customers did not do waste management system before. To ensure GN Oil Water and Solids Separation Systems can applied for their applications, GN Solids Control specially designed a one-skid compact Oil Water and Solids Separation System for trial purpose. GN one-skid Oil Water Solids Separation System is in stock for sale. Clients can buy the small system as trial base to show to their clients their capacity to do the projects. For clients in China, they can choose to buy or rent the one-skid system.

If clients do not want to buy the one-skid compact Oil Water and Solids Separation, they can send their oil sludge or waste material to GN Solids Control. GN Solids Control can do the separation at GN factories and show clients the performance. After separation, GN Solids Control can do lab test and show the final output specs to the clients.


This week, a package of oil sludge treatment system was departed to an oil field service company in China. The unit will be used to recovery oil sludge from oil base drilling cuttings. The oil sludge treatment system including below items:
1) 2 phase decanter centrifuge. Material fed to 2 phase decanter centrifuge must be with solids content Less 20% and Particle Size less than 20mm.
2) 3 phase disc centrifuge. The solid phase material entering the three phase disc separator usually shall be reduced the solid content to less than 3% and the solid particles to less than 400 micrometers by the decanter centrifuge, then the three-phase disc separator can achieve the best effect.

3) Transfer pumps
4) Dewatering chemical dosing system with dosing pumps and automatic control system
5) Transfer tank and holding tanks for mud recovery and mud transfer.

The project is for processing oil and solid wastes in sludge storage tanks. After the oily sludge wastes have been pre-treated. After the oil sludge wastes have been treated by sieving, sand washing, demulsify, and finely screened, they have now achieved reductions and preliminary separation. After that, the oily sludge will be treated for three-phase separation.

Two phase decanter centrifuge and three phase disc centrifuge is used in the three phase separation process. After three phase centrifuge separation, the final outputs are soil, oil and water.

Chemical dosing system is used before 2 phase and 3 phase centrifuge separation to help for the removal of as more fine solids as possible.

Besides 2 phase decanter centrifuge, 3 phase disc centrifuge and chemical dosing sytem, GN Solids Control also offers other oil sludge treatment and transfer equipment, like 3 phase decanter centrifuge, high G drying shale shaker, mud cleaner, Vertical cuttings dryer, Drilling Cuttings Solidification Unit, Thermal Desorption Unit (TDU), oil water separator, sludge vacuum pump, screw conveyor, etc…

Recently, GN Solid Control has completed the design and manufacture of a set of oil sludge treatment system for an oil field environmental protection company in China. Since the oil sludge treatment system was launched on the market, it has been widely concerned by customers no matter in China or outside of China, and the feedback from the on-site operation of the market is good. More and more oil field environmental protection contractors inquire and order the system as an important solution to reduce the content of harmful substances in oil sludge efficiently and economically.

The oil sludge treatment system has two separation principles: chemical dosing and physical separation after heating. GN oil sludge separation system is composed of several modules with different functions to gradually recover water and oil from the sludge. The following is a brief introduction of the system:

1) Sludge vacuum transfer pump module – the sludge from oil-based mud drilling cuttings has high viscosity and high sludge content, which requires a powerful and efficient conveying device to suck the sludge out of the mud pit and feed to the oil sludge treatment system. GN sludge vacuum pump is a fully pneumatic pump with no electrical components and does not produce any sparks in use. it is especially suitable for oil and gas explosion-proof environment. With 85Kpa vacuum, the viscous sludge can be sucked and discharged to other place far away.

2) Pre-mixing module – before the sludge is fed into the separation module, the material needs to be homogeneously mixed to more than 80% of the liquid content. At the same time, in order to enhance the separation effect of oil and mud, it is necessary to add chemicals in the process of homogeneous mixing.

3) Separation module – GN Solid Control uses different separation equipment to separate oil and water from the sludge step by step. High G force shale shaker, 2-phase decanter centrifuge and 3-phase disc centrifuge are used in the Separation module.