Blue Flower

The principle aim of waste management is to ensure that waste does not contaminate the environment at such a rate or in such a form or quantity as to overload natural assimilative processes and cause pollution. Eliminating or minimizing waste generation is crucial, not only to reduce environmental liabilities but also operational cost. Many disposal practices of the past are being questioned now. As inadequate waste handling eventually leads to environmental damage and financial liabilities, systematic waste management through integrated environmental economics became a preferred approach in the up stream phase of the petroleum industry.

Decanter centrifuge and vertical cuttings dryer has become a popular approach to avoid the environment damage and save high drilling waste cost.

Decanter centrifuge GN vertical cuttings dryer
Historically, waste pits (reserve pits) were used at land rig sites. At the end of each well the wet cuttings left to dry naturally and then bulldozed or covered with natural soil. More recent history the cuttings were dug out and trucked to landfill, where a significant cost is incurred as the cuttings were treated purely as waste material current practice for operators onshore and offshore employs extensive fluids recovery and drilling cuttings disposal methods. Often, because they want to be considered responsible guests by their host country, oil and gas operators impose even more stringent environmental regulations on their operations than those imposed by the country in which they are drilling. E&P waste- management has evolved beyond the traditional drill cuttings and excessdrilling fluids during drilling and workover operations. Though these comprise the vast majority of the wastes other materials include contaminated water, material and chemical packaging, emissions such as carbon dioxide, scrap metals, fuel, lubricants and other oils as well as the usual human and industrial wastes associated with E&P operations.
Shell Exploration and Production Company established a Rig Waste Reduction Pilot Project in 2001 to identify potential waste reduction strategies. Their preferential hierarchy that they developed is: reduce, reuse, recycle, recover and dispose. The major of the total waste stream was found to be drilling discharges and non-hazardous oilfield waste. Mud use was reduced by 20% and mud component packaging was reduced by 90% through a combination of solids control efficiency, vertical cuttings dryer technology and bulk mixing equipment. In addition, Shell implemented a sorting, compaction and recycling process for solid waste (consumables and trash) to reduce landfill disposal.
Schlumberger has introduced a total waste management program to mitigate rising quantities of landfill waste. Benefits included an overall improvement in general housekeeping that reduced health and safety exposure and a general increase in environmental awareness and concern. Mobil implemented a waste management program for the Hugoton field operations.
The waste management system decreased overall waste-related costs while improving compliance assurance and reducing potential liability. The key element was a mechanical solids control system consisting of a semi-closed loop centrifuge flocculation dewatering process that removes solids for burial on location.Waste management, however, incorporates other aspects in addition to drilling fluids and cuttings. Air emissions and water runoff from the site should also be considered. With the increase in rig activity in the Rocky Mountain states, pollution from drilling rigs and other oil field related equipment has become a concern.

GN decanter centrifuge is now available from Huston, Texas USA. Clients of America, Canada and Latin America can buy centrifuges from Huston Warehouse. GN Solids Control (China) with her subsidiary Solids America LLC located in located 6710 Windfern Road, Houston, TX 77040, is the first Solids / Liquid Separation Equipment manufacturer from China that set foot into the US market.

A number of GN high standard decanter centrifuges are now working in the America Oilfield. There is no doult that GN decanter centrifuges can meet the performance requirement and environment regulations of American oilfield.

Now we have GNLW363 decanter centrifuge for sale in Huston, Texas
GNLW363 Decanter Centrifuge is the most popular size centrifuge in the oil drilling industry. It can be used for fine/ultra fine solids separation, barite recovery and zero-discharge dewatering. With it’s removable legs, the GNLW363 can be used on solids control mud tank system or the telescopic skid for drilling waste management. GN have the fixed speed available with different pulley for option to change speed, and VFD drive with PLC control available for your different applications. With sales of 150 Sets of Centrifuge every year around the world, you can see GN centrifuge all working all around the world.

High Decanting Bowl Rotational Speed
Bowl speed adjustment is usually achieved by variable frequency motor or hydraulic motor. The greater is the speed, the greater is the centrifugal force and high centrifugal force helps improve the mud cake dryness.

Excessive Decanting Bowl Rotational Speed
But excessive rotational speed will destroy sludge flocculation, and reduce the dewatering effect. At the same time, the higher speed requires more strictly for material. The wear and tear on the decanting bowl and drum increase, meanwhile, the power consumption, vibration and noise will be correspondingly increased.


Conclusion
It is not true obviously that the higher the speed, the better the decanter centrifuge. You have to balance the rotation speed with the actual service centrifuge material. GN decanter centrifuge main material:
1. Top brand material, e.g. bearing we used SKF or FAG
2. Screw propeller protected by tungsten carbide tiles
3. Bowl assy is made of stainless steel 316
4. Welding connection of straight cone and taper cylinder.

GN Solids Control branded decanter centrifuge are big bowl, big volume, high G force available. Please visit Decanting Centrifuge page for more information.

In weighted, oil-base mud applications, decanting centrifuges are operated in series. The first unit returns the coarse solids fraction (weight material) to the active system, with the light, liquid fraction being routed to a holding tank (rather than being discarded as in a classic weighted mud application). A second unit, often a higher capacity machine, strips out the solids and discards them, returning the effluent to the active mud system.


This process is not as effective as a single unit for viscosity control — a large portion of the colloidal size solids are returned to the active mud system in the effluent stream of the second unit — but the effluent stream from the first unit is too valuable to discard, especially with synthetic oil muds. Usually the coarse solids fraction is discarded and the base fluid is retained for re-use.

In oil based mud applications, a kind of vertical centrifuge - Vertical Cuttings Dryer is often used for drying the drilled solids in order to reduce the drilling waste volume.

GNLW452S decanter centrifuge was ready for delivery to Kazakhstan. This is a middle speed decanter centrifuge which operates 815 G’s at bowl speed of 1800RPM with 2-5 micron solids removed.

Decanter Centrifuge to Kazakhstan 001
Driven by one 45kw (60hp) electric motor, the normal operating flow capacity of this unit is 176GPM (40M3/h) and can reach maximum to 250GPM (57m3/h). The solids bowl diameter is 450mm (17.7inch) and bowl length 1100mm (43.3inch).

Decanter Centrifuge to Kazakhstan 002
In Kazakhstan, GN has gained the good fame. Beside the decanter centrifuge unit, GN also have HDD Drilling Mud Recycling Unit Working in Kazakhstan.

In the classic weighted mud application the solids discharge (containing the majority of the weighting material) is returned to the mud system. The liquid effluent (containing the majority of the colloidal size solids) is discarded. As part of a“closed loop”, larger high capacity (75–250 GPM) decanting centrifuges (and sometimes standard centrifuges) are used to maximize fine solids removal. The coarser solids fraction is discarded in dry form, while the liquid and colloidal solids fraction is returned to the mud system.

decanting centrifuge

Decanting centrifuges are becoming more popular for processing unweighted oil mud, especially if
1) the mud has been brought in from another location and may contain a large amount of fine drilled solids,
2) slow, hard drilling with a gradual buildup of ultra-fine solids is anticipated or
3) the liquid mud phase is valuable.
GN offers Decanting Centrifuge for unweighted mud applications.