Principles of HDD Solids Management

The evolution of drilling fluids paired with the ever-increasing cost of waste management and disposal allows for an easy conclusion to be drawn in connection with the economic practicality of including drilling fluids in the HDD process. The economic feasibility is highly dependent on the ability to recover and recycle the products. There is no question—the cost of the HDD business is rising. While barite and bentonite have become considerably commoditized over time, critical additives continue to rise in price, impacting overall costs. Additionally, the cost of qualified talent has escalated dramatically, leaving HDD rig operators with a difficult question: How can they continue to generate profits when business costs are rising exponentially?

When evaluating and choosing a package mud reclamation system, many important considerations must be kept in mind. The following guide offers a high-level overview of the critical components of HDD solids control and drilling fluid management. Of course, this guide is not all-encompassing to every set of circumstances. Therefore, it is essential to discuss your individual needs with the supplier of the drilling fluid and the original equipment manufacturer of your solids control and waste management equipment. That discussion, paired with an understanding of the content below, will help guide your business decisions effectively and strategically in the right direction.

Particle Size & Effects

The oil and gas industry is unique to the HDD industry. While the former uses both oil- and water-based drilling fluids, HDD drilling fluids are expected to remain water-based due to local laws and regulations that make oil-based drilling fluids impractical—especially when drilling near the surface.

As indicated by their name, water-based drilling fluids rely upon water as the liquid solute (or the media the additives are mixed into). The solid component of any drilling fluid is either commercial solids or drilled solids. Commercial solids, like bentonite, which is used as a thickening agent to increase the fluid's viscosity, typically have a relative particle size between less than one micron—or 0.000039 inches—to ten microns—or 0.00039 inches. A commonly utilized weighting agent, barite ranges from one micron to one-hundred microns. In examining Figure 1, which highlights particle size distribution from four different barite suppliers, please remember that a micron is 1/1000 of a millimeter—and there are 24 millimeters in one inch.