When stuck between a rock and a hard place, I was determined to come up with a solution to penetrate very coarse alluvial gravels, where traditional split spoon and Shelby-tube sampling methods could not.

The BLN Sample Hammer, the proprietary technology I developed, offers an alternative sampling method compatible with air rotary and air rotary casing advance systems. The technology combines the power of an air hammer with the superior sample quality once only associated with sonic drilling methodologies. It consists of a specially designed air hammer body and dual-tube core barrel to reduce sample refusal — all while providing excellent sample recovery in most unconsolidated formations.

The sample is driven in advance of the boring, so it is not exposed to a circulation medium that may otherwise penetrate or dilute the contaminant. When the project requires a sample where VOCs may be present, or the geologist needs to see if there is staining within the capillary fringe, this tool makes all the difference. The sample is driven much the same as a sonic core, but without the heat-producing vibration. The sample is captured in a sleeve to prevent volatizing and ensuring any volatile organics remain.

First used in remote mountain-front terrain in southern New Mexico, the system is ideal for use in unconsolidated alluvial material with both loose and tightly bedded gravels. It is the type of complex geology I had in mind when designing the system. The crew working the New Mexico jobsite was able to significantly increase alluvial soil sample recoveries relative to previous investigation efforts. In difficult environmental sampling conditions where drilling with water is not an option, the BLN Sampler allowed the collection of soil samples that would otherwise have been impossible to collect. 

The BLN Sample Hammer has proven successful on complex drilling sites throughout the western United States. The custom tooling offers the benefits of high quality samples through a robust drilling technology. Fitted on an existing rotary platform, it reduces the need for additional rig mobilizations, safely completing projects on time and on budget.