How can I identify an inadvertent return and how can I fix it?

By Trenchlesspedia Staff | Last updated: July 7, 2023

In the geotech surveys on most horizontal directional drilling (HDD) crossings, the soils being drilled are identified. So you can plan ahead with drilling programs best suited for the terrain you'll be drilling. With certain soils, you can almost expect inadvertent returns because you're pumping through sensitive areas at high pump rates.

Lower mud levels in the pits are one of the first signs of an inadvertent return along with reduced pressure readings in the drill cab. An easy way to identify an inadvertent return is if you see it fracture up into the the ground. Having Lost Circulation Material (LCM) products on location is a cost-effective way to remediate inadvertent returns and reduce downtime. Most LCMs are designed to be spotted/squeezed, and/or swept through "thief zones" at the onset of the inadvertent return.

Essentially, you're looking to seal unconsolidated and loose soils with the LCM. Knowing the calculations to spot the LCM pill in the exact location is paramount to the success of the spotting procedure, so, having a qualified Mud Engineer on location is highly advised.

Share this

  • Facebook
  • LinkedIn
  • Twitter
Trenchlesspedia Staff
At Trenchlesspedia, we deliver educational content about trenchless construction and trenchless rehabilitation technologies and methods. Our aim is to connect trenchless industry professionals to the solutions and issues that matter most with our complete source of industry-specific information and answers.

More Q&As from our experts

Term of the Day

Industrial Radiography

Industrial radiography is a non-destructive method of assessing the conditions of pipes using electromagnetic radiation in…
Read Full Term

Don’t Miss the Latest From Trenchlesspedia!

Subscribe to our newsletter to get expert advice and top insights into every aspect of trenchless construction and rehabilitation. We create top educational content for and about the trenchless industry, insuring you have the knowledge you need for successful trenchless projects.

Go back to top