Centrifuges Greatly Enhance Fluid Recycling

June 2014, Vol. 69, No. 6

A centrifuge also can be used as a barite recovery system or dewatering system, a practice widely used in the oil and gas industry. The dewatering process, said Anderson, allows up to 100 percent removal of all suspended solids from the drilling fluid. The reclaimed water can be used to make up new mud for another job or as rig wash-down water.

However, the use of a centrifuge is not appropriate for every HDD project.

“It comes down to drilling fluid volume and the complexity of the drilling fluid additives used,” said Anderson. “Small jobs might use 100 to 300 gallons per minute of circulating drilling fluid. Consequently, Kentron’s experience has been that the break-even point for a centrifuge-enabled system is for longer, wider-diameter bores requiring at least 400 gallons per minute of recirculation.”

Drilling fluid “life,” he added, is dependent on the particle size distribution of the
solids generated and the degradation life cycle of the solids within the drilling fluid.

Anderson said that incorporating a centrifuge into a recycling system has benefits in addition to fluid savings, such as increased production.

“Studies have shown,” Anderson continued, “that the lower the colloidal solids content in a water-based drilling fluid with particulates in sizes less than 2 microns, the faster the rate of penetration. Minimizing colloidal solids lowers the plastic viscosity of drilling fluid, contributing to greater horsepower at the bit.”

More benefits

In addition, he explained, cleaner fluids reduce wear on pumps and wear seals, contributing to longer equipment life.

“Oil and gas drillers utilize the centrifuge to minimize waste and to manage the weight of the mud prior to recirculation,” said Anderson. “It has only been over the last decade that HDD companies have been adopting such systems into the HDD drilling operations.”

Kemtron currently manufactures three centrifuge models for HDD applications. Several companies offer centrifuges for HDD work, some are available for rent.

“However,” Anderson said, “of all the HDD mud reclaimer manufacturers, Kemtron is one of the only companies that manufactures both packaged mud systems and centrifuges. Contractors routinely shop multiple companies to put together packages that we already offer – Kemtron has a product line that incorporates conventional drilling fluid recycling equipment and centrifuges into one integrated package.”

Anderson foresees continuing growth in the use of centrifuges on HDD projects.