Drilling fluids decanter centrifuge used at offshore platform

Recently, good news comes from KOSUN Marketing Center that KOSUN has won the bid for dedicated drilling fluids decanter centrifuge used at offshore platform of a CNOOC subsidiary by virtue of its excellent product performance and perfect after-sales service system. Three DC355-VFD centrifuges (LW355×1257N-VFD) will be delivered to CNOOC Enping Oilfields, servicing at Enping-231 and Enping-181 offshore drilling platforms.
Debugging for Main Engine of DC355 High Speed VFD Centrifuge It is worth mentioning that length-diameter ratio of the bowl for this bid-winning DC355 high speed VFD centrifuge is 355×1257 and the maximum speed is up to 3800rpm. This model has been enjoying popularity among major drilling companies and oilfield service companies after its launch on the market in 2013. It is particularly suitable for drilling waste management and has yielded extraordinary results on domestic market of drilling waste zero discharge. As core equipment for drilling fluid recovery and solids treatment and discharge, this centrifuge has excellently completed each solids control and drilling waste management task.
These three DC355-VFD high speed decanter centrifuges winning the bid are equipped with dedicated CCS certified motors. Both anticorrosion and painting on equipment surface meet use standards of offshore drilling platform. Electrical appliances of well-known German brand are adopted for electrical control unit. The bowl adopts hard alloy empiecement process, which is stronger and more wear resistant compared with inferior ceramic empiecement technology, especially meeting remanufacturing standards for refurbishment and reinforcement of screw conveyor separately (which is impossible for ceramic empiecement). It is these advanced process and manufacturing standards that make KOSUN stand out among numerous competitors.
Hard Alloy Empiecement Process of KOSUN DC355-VFD Centrifuge Conveyor KOSUN Centrifuge in Service on a COSL Well Site at Gulf of Mexico KOSUN Centrifuge in Service on an Offshore Drilling Platform in Middles East
Cooperation between KOSUN and CNOOC can be traced back to the year of 2007, when KOSUN provided two drilling fluid centrifuges for COSL for its PEMEX project, and since then, KOSUN has been unceasingly delivering centrifuges to offshore drilling platforms of COSL. Moreover, KOSUN centrifuges have also serviced at offshore drilling platforms in North Africa, South America and other regions and won praise from customers at home and abroad.

Drilling waste management equipment of high performance

Lately, the performance of KOSUN drilling waste management equipment (After being treated by KOSUN Hi-G dryer, the mud is ≤1.03 in specific gravity) attracts many customers from different zone, which have approached KOSUN technical service engineering team in Wushen County oilfield drilling site in Inner Mongolia from Henan, Xinjiang, etc. These customers examined running conditions and treatment effects of KOSUN drilling waste management equipment on the oilfield site.
KOSUN technical service engineering team explained process flow of KOSUN drilling waste management system, working principles of centrifuge and Hi-G dryer to customers based on the live treatment system while drilling, and showed them excellent treatment effect of Hi-G dryer and vertical cuttings dryer. Below is the operation video of Hi-G dryer.
Field Operation KOSUN technical service engineering team has successfully completed maintenance of the drilling waste management system and is moving to another well site in Wushen County for engineering services of treatment while-drilling.
Another set of KOSUN drilling waste management system has delivered to the drilling crew, and installation and debugging are about to begin.
Perspective View of Oilfield
Besides providing More-Than-Customized services, one-stop drilling fluid solids control products and waste management products, KOSUN focuses more on the ecological environment we live in, devoting itself to research and development of multi-field environmental protection products to facilitate clean oilfield production and maintain clear water and blue sky, aiming at taking resources from the environment and returning cleanliness to the environment.

KOSUN solids control products sent to Russian market

In fruitful October, delivery for several sets of solids control systems customized for a Russian customer has all been completed. This successful cooperation between KOSUN and the Russian drilling service company further expands share of KOSUN solids control products in Russian market once again. Both parties have agreed to establish long-term strategic partnership in line with principles of mutual benefit and joint development.
KOSUN Production & Machining Center Vacuum Degasser Ready for Delivery Jet Mud Mixer Ready for Delivery KOSUN has set up a product accessories warehouse in Nefteyugansk in a Russian oil drilling block. Currently, shale shaker and large numbers of screens are stored in the warehouse, which allows KOSUN to provide a series of localized services of solids control products for numerous Russian drilling companies.

Now, KOSUN products have occupied a decisive market share in Pan-Russian regions and won favorable word of mouth. KOSUN has been sticking to winning markets by virtue of product upgrading and technological innovation and acutely grasping customers' demands, winning great reputation in the industry for stable product quality, personalized product customization services and perfect global after-sales services.

The important solids control component hydrocyclone

A hydrocyclone is most often used to separate "heavies" from a liquid mixture originating at a centrifugal pump or some other continuous source of pressurized liquid. A hydrocyclone is most likely to be the right choice for processes where "lights" are the greater part of the mixture and where the "heavies" settle fairly easily.
In oilfield drilling mud solids control system, hydrocyclone is usually installed on mud desilter, desander and mud cleaner. It is the most important solids control component for them.

For the work principle of hydrocyclones, it works like this. First, the drilling fluids is sucked up to 0.25Mpa ~ 0.4Mpa by sand pump, and enters into the cones through the side inlet which is normally only 2-1/2″ in diameter. The fluids then flows spirally inside of the cone. Effected by the centrifugal force, the heavy solids in the fluids would be thrown towards the inner wall of the cones, go down to the bottom, and discharge through the sand discharge port, while the light fluids would go up and discharge through the upper outlet. The diameter of the bottom discharge port is adjustable, and with a cover of hydrocyclone.

The main types of decanter centrifuge

The main types of decanter centrifuge are the vertical orientation, horizontal orientation and Conveyor/Scroll.
In vertical centrifuge,also called vertical cuttings dryer in DWM control field, the rotating assembly is mounted vertically with its weight supported by a single bearing at the bottom or suspended from the top. The gearbox and bowl are suspended from the drive head, which is connected to the frame. The vertical decanter allows for high temperature and/or high-pressure operation due to the orientation and the rotational seals provided at one end. However, this makes the device more expensive than the horizontal decanter centrifuge, which is non-pressurised and open. The advantage of the vertical machine over the horizontal machine is that the noise emitted during production is much lower due to less vibration.
In horizontal decanter centrifuge, the rotating assembly is mounted horizontally with bearings on each end to a rigid frame, which provides a good sealing surface for high-pressure applications. The feed enters through one end of the bearings, while the gearbox is attached to the other end and is operated below critical speed. Capacities range up to 40,000 pounds (18,000 kg) of solids per hour with liquid feed rates of up to 300 US gallons (1.1 m3) per minute. The horizontal machine is arranged in a way that slurry can be introduced at the centre of a rotating horizontal cylindrical bowl. The scroll discharge screw forces the solids to one end of the bowl as it is collected on the walls. This orientation is the most common design implemented in industry.

In conveyor decanter centrifuges the conveyer or scroll fits inside a rotating bowl and carries the solids settled against the wall, pushing them across a beach towards the underflow where the solids discharge. The conveyor allows for an increase in separation efficiency and feed capacity.

Decanter centrifuge functions for various industries

Decanter centrifuge is used to separate (dewater) solid materials from liquids in solids control system when they are mixed together in mud. Besides, decanter centrifuge is applied in many industries such as:
1. Solids separation (oil well drilling, refining, de-watering)
2. Industrial and biological wastewater treatment
3. Food processing (olive oil, wine, fruit juice)
4. Fish processing (fish meal, fish oil)
5. Chemical slurry

Decanter centrifuge is driven by two motors. The main motor drives the drum and the outer casing of differential through belts while the auxiliary motor, after the differential shifting speed, drives the spiral propeller. This will make the drum and the spiral propeller rotate in the same direction with a certain differential speed. There are several different types of decanter centrifuges, such as: Vertical, horizontal, or scroll (conveyor).

Mechanical separation technology of decanter centrifuge

The rapid development of the decanter centrifuge over the 20th century saw it expand into a vast range of over 100 industrial applications. Further development since then has seen the refinement of machine design and control methods, improving its overall performance, which allows the system to respond quickly to varying feed conditions.
The newest development in decanter centrifuge technology aims to achieve enhanced control of the separation process occurring inside the decanter. The way in which manufacturers aim to address this is by utilising variable mechanical devices in the rotating part of the decanter centrifuge.
To control the separation process, the operational parameters should be transferred from the rotating part to the stationary part of the decanter whilst also constantly controlling and maintaining the mechanical device inside the process region. This can be achieved using hydraulic and electronic transfer systems. A hydraulic drive motor is easily able to access the rotating area of the decanter centrifuge.
There are numerous manufacturers specialising in mechanical separation technology that have adapted these new designs into industrial standard equipment. This advanced technology has allowed decanter centrifuges to operate up to 250 cubic metres per hour and has developed numerous designs such as the Z8E decanter, known as the world's largest decanter centrifuge with an adjustable impeller, which supplies a torque of 24,000 newton metres. Other designs can reduce power consumption by up to thirty percent due to a large slurry discharge, and are best utilised in the water treatment industry.

Decanter centrifuge is the last stage equipment in drilling mud system for solids control and mud cleaning. The superiority of decanting centrifuge is embodied in the solids processing size. Decanter centrifuge could remove the solid particles with size 2-7 microns using the principle of centrifugal action, it is an ideal choice for separating particles in drilling mud. Always there is a screw pump or submersible pump to feed the mud to decanter centrifuge.