DWU-250 Dewatering Unit

The BRANDT DWU-250 dewatering unit minimizes waste volume from closed-loop drilling operations, reserve pit closures, and site remediation projects.


Processing drilling fluid in sensitive environments

As part of the family of proven liquid/solids separation products and services available from NOV, the BRANDT™ DWU-250 provides dependable service and simple operation in a variety of applications and locations.

The DWU-250 is used with one or more decanting centrifuges as part of the chemically enhanced dewatering (CED) process to treat 50 to 350 barrels of fluid per hour. The liquid phase can be less than 1% total suspended solids to relatively solids free, depending on the type of feed fluid and degree of clarity required.

The CED process

The CED process consists of injecting premixed conditioning and/or flocculating chemicals with the feed mud entering a decanting centrifuge. This increases the amount of ultrafine solids that can be separated from the liquid phase of the fluid. The process can be used on weighted and unweighted closed-loop drilling mud systems. The CED process is also an important part of waste pit closures and other site remediation projects.

For best results, high-performance solids separation equipment should be installed upstream from the DWU-250. After the fluid is processed by these units, it is routed to the DWU-250 and one or more decanting centrifuges. The number of centrifuges used is determined by the processing requirements.

Unitized, modular design

The DWU-250 has mixing tanks, pumps, piping and connection points, controls, quality check points, and test facilities. All are permanently installed in a weatherized enclosure.

The mixing and aging tanks are equipped with educators and mechanical agitators for mixing bulk flocculants, coagulants, and other conditioning chemicals. The DWU-250 uses powdered or liquid chemical concentrates. The tanks are calibrated for easy reference when mixing specific volumes or concentrations of chemical solutions. A preplumbed water distribution system enables simple and efficient mixing.

Positive displacement, metering, and injection pumps provide accurate addition of fresh water and chemical solutions from the mixing tanks to the centrifuge. Piping and addition points are acid resistant to reduce corrosion and provide long, dependable service. Connections and operating controls are conveniently located and clearly labeled to simplify installation, operation, and repair. Each unit includes a quality check tank to monitor centrifuge effluent. Online adjustments may be made as the mud is being processed. If preferred, the mud may be batch treated (dewatered) and returned to reserve tankage before being transferred to the active system. The lab area/workbench provides a convenient place to pilot-test chemical type and concentration for a specific project. Usually, the same chemical solutions are used throughout a job. However, some of the chemical solutions require adjustments due to changes in feed slurry, water source, or other factors.

All equipment is mounted on a skid or a trailer-mounted enclosure with large access doors. The DWU-250 can be supplied with air conditioning, Arctic heaters, or both, depending on anticipated operating conditions. All units are insulated and feature a master control panel, environmental controls, and interior lighting. All components are easily accessible and provide dependable performance in remote locations. A wide variety of custom options include door and window placement, interior and exterior finishes, a lab/test area, and detail and placement to meet specific application requirements.


  • Weatherized enclosure
  • Eductors and mechanical agitators
  • Preplumbed water distribution system
  • Calibrated tanks
  • Acid-resistant piping and addition points
  • Quality check tank for monitoring
  • Lab area/workbench
  • Skid or trailer mounted
  • Arctic heaters, AC, or both
  • Master control panel
  • Wide variety of custom options


  • Continuous or batch mixing
  • Provides water for reuse or disposal
  • Recycles dissolved chemicals
  • Improves drilling fluid properties
  • Reduces drilling fluid cost
  • Reduces disposal volume
  • Produces “paint filter specification” solids
  • Improves effluent clarity
  • Reduces water requirements
  • Allows smaller location
  • Reduces clean-up cost

DWU-250 Dewatering Unit Specifications

Dimensions (L × W × H) 20 × 8 × 8 ft
Weight 12,500 lb (5681 kg)
Process rate 50 to 350 bbl/hr
Electrics 230/460 VAC, 60 Hz or 190/380 VAC, 50 Hz
Models Standard, Arctic, tropical, or custom
Electrical requirements 6.26 hp, 84.0 FLa