In a perfect world, drilling fluids for each project would have exactly the right properties for the job at hand and the work would go as planned. But, sometimes, changing conditions downhole—e.g., shale, rock, sand or salt—require further modification in water loss properties, rheology control or viscosity modification. On site, particularly in small-footprint applications such as water well or horizontal directional drilling (HDD), there simply is not enough physical space to bring in complex equipment needed to disperse classical water soluble polymers. In these applications, a driller could be bringing a rig on to a homeowner’s front yard, between two buildings, or alongside a highway and not have the room for all equipment. In these “equipment challenged” applications or when faced with cold weather conditions, which also can slow mixing, polymers that easily disperse and become usable in a reasonable amount of time become necessary.
Drilling fluids are used to maintain wall stability, control fluid loss through their water-retention properties, enhance the ability to suspend cuttings and improve the ability to plug open formations. Whether water well drilling, HDD or tunneling, each project has its own drilling fluid requirements. The selection of additives is key in delivering value to the drilling operation and the friendliness of the drilling fluids.