Common Questions About Rotary Drilling, Part 1

Between the two of them, Operations Managers Bryan Nydoske and Mike Mottet have 81 years of drilling experience, which they drew upon for a popular webinar last month about rotary drilling. Titled Drilling 104: An Introduction to Rotary Drilling, it is the most well-attended webinar in Cascade history.

If you weren’t able to catch the live webinar, it’s now available to watch on demand.

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Participants submitted a lot of great questions covering a variety of applications and scenarios, and in this blog post, we share Part 1 of Bryan and Mike’s responses.

IS THERE A DIFFERENCE IN THE AMOUNT OF SOIL CUTTINGS THAT EACH ROTARY DRILLING METHOD GENERATES?

Using air rotary, you can expect your cuttings to grow from actual borehole volume by 15% to 20%. If you’re using mud, you’ll have the same solids volume, and mud will be three to four times the volume of the original borehole volume.

As with everything else in drilling, there’s always an “it depends” clause. For example, if you’re drilling with air and get below the water table, you may generate some water—do you consider the entire volume of everything that is removed from the borehole? It depends on what you mean when you use the term “cuttings”—whether you’re referring to that which came specifically from the formation or if you mean all the waste generated during the drilling process.

WHAT ARE THE BENEFITS OF ROTARY DRILLING OVER HSA OR SONIC DRILLING?

It really all depends on the project, and what depth and diameter are required. Rotary drilling is not inherently better than HSA or sonic drilling, it just happens to better in some specific applications. If someone tells you otherwise, you may want to ask why they would say so.

For example, some companies may direct you to the technology that falls in their wheelhouse—whatever limited drilling methodology they provide with their equipment and drill operators. “It’s the best option” may mean it’s the best they are able to offer you, but not necessarily the best for your project’s lithology, timeline and budget.

At Cascade, we provide the complete range of drilling technologies, so we aren’t invested in suggesting one specific thing. It allows us to evaluate your project and recommend the best method and value each time.

CAN SAMPLING BE CONDUCTED USING ROTARY DRILLING?

Absolutely. Almost every type of sampling available can be run in conjunction with rotary methods. Everything from coring soft sands and alluvial formations to split spoon sampling to core drilling. We also have proprietary methods that allow us to take a core sample that has not been exposed to any circulation medium, which can be especially helpful if there are suspected VOCs.

If you’d like to learn more about rotary drilling, come back in a few weeks for Part 2 of Bryan and Mike’s Q&A.

Can’t wait that long? Watch their webinar, Drilling 104: An Introduction to Rotary Drilling.

WATCH NOW >>