Winter Drilling & Sub-zero Operations

Information courtesy of an article published in Trenchless Technology Canada

With the Fall season behind us and colder months ahead, winter drilling comes with its own set of demands, especially for those customers in the northern states and Canada. When sending equipment and crews out into frigid temperatures there are a number of things to keep in mind. Using the right equipment can ensure that a drilling operation is getting the most out of its people and machines.

Equipment Considerations

The drill string can be the first piece of equipment impacted by the challenges of a winter drill. As rods are made up and broken apart, the threads and shoulder of the pipe can take a beating; going into the ground on every shot and resulting in poor makeup and binding issues. “And when this happens at -40 C, it is just no fun,” says Michael Criss, the HDD specialist with Tecvalco Ltd. “But you can prevent this. If you do not regularly change out the lead rod on your drill string, now is the time to shuffle that first piece of drill steam to the back of the basket.”

Drilling Fluids in Sub-zero Temperatures

All fluids are crucial when drilling in winter conditions, be it anti-freeze, drilling fluids, or even thread lube. Often overlooked, thread lube is a very important part of winter drilling operations, especially in sub-zero situations. Freezing temperatures can be offset by utilizing arctic-grade thread lube, such as Melfred Borzall’s Auntie C’s: Arctic Grade notes Criss, which will work with auto-greasing mechanisms on the coldest of days. This product provides superior lubrication at low temperatures and can be purchased economically in a variety of volumes.

 

 

Tooling Choices in the Cold

While many areas already have challenging conditions to drill through, adding frigid air and frozen ground increases the operational difficulty — especially when it comes to the pilot shot. Drillers often prefer to use dirt bits or paddles (blades) to pilot out and there are a wide variety of designs available to suit virtually any ground type or drill.

 

The Steep Taper UltraBit from Melfred Borzall excels in hard drilling conditions. This blade features an aggressive center carbide on the point of the blade, carbide blocks down the sides and loads of chunky hard-facing, and powers through difficult winter ground with ease. Another great feature is this blade can be rebuilt at a fraction of the cost of replacing when wear and tear finally catch up with it. Another Borzall blade that works well for winter conditions is the Rock Saw. This blade has a low profile, bull-nosed, and contoured back design to minimize torque-stealing drag and excels in hard ground and cobble conditions.

 

Other Borzall tools that fit well into winter drilling include Iron Fist and Eagle Claw SD hard soil bits. The Iron Fist is well suited for cobbled ground and allows for superior steering while maintaining forward momentum. The design uses replaceable carbide “blocks” that wrap across the drilling face of the bit. This protects the body of the tool, allowing for quick and inexpensive replacement of the “blocks”. The mud ports are located high up the steer face, which helps keep them from getting clogged with fine rocks, cuttings, or other winter debris. This also helps to wash sticky clay off the steering face and keeps the bit running true.

 

For those really difficult conditions, there are even more aggressive tools, such as the Eagle Claw SD. This bit features a trifecta of aggressive carbide cutters that fracture and chew through the more solid ground with ease. The carbide pins are quickly removed in the field, allowing the driller to change out the cutters and get back to work fast.

 

Using the right tools for the pullback part of the drilling process is also an important consideration in the winter. Melfred Borzall’s Fast-Back tool swap system allows a driller to pilot out with one of their bits and then with the pullback device, quickly and easily attach a swivel for the pullback of the product pipe. Less time changing over means less time out in the cold.