In August 2015 DTD mobilized to a mid-Atlantic air national guard base to supplement an existing remediation system by adding a horizontal air sparge well. The airfield is in the Piedmont Physiographic Province, and accordingly, is underlain by saprolite that grades into fresh granitic bedrock. This which passes directly under an active taxiway, was made more challenging because the drilling had to pass through 40′ of construction debris (concrete, rebar, & man-made materials) before reaching the hard clayey saprolite.
We mobilized our American Augers DD210, to complete the well and added a hydraulic mud motor to increase the penetration rates. Even with the large rig and mud motor, drilling was slow due to the hardness of the geologic formation and the difficulty steering. The fractured and collapsing ground necessitated the use of DTD’s Knock Off Technology to install this well as a blind well. The total length of the well was ~652′ and included 200′ of sparge screen.