How deep do you drill in rock & overburden?

Drilling in Rock and Overburden 1.1 Methods − Typically 3 to 12‐inch diameter. − Typically ≤ 200‐foot depth. − Typically within 30° of vertical or horizontal. − Mostly beneath the water table.

What is a hydro-lock drill?

Hydro-lock – drilling term – A condition where the well casing and screens become “locked” in the borehole during pullback. This occurs when fluid becomes trapped inside the borehole behind the well materials. Suction increases to the point where the drill can no longer pull the casing into the hole.

How does a drill head work?

The driller can literally move the drillhead up, down, left or right underground. This is accomplished by drilling a pilot bore into the ground at an angle and then leveling out at a specified depth. Once the proper depth has been reached, the pilot bore is typically advanced horizontally a specified distance and then back to the surface.

Do you need a drill rig to jet a well?

Jetting is recommended in clayey soils or in wells where the screens are longer. Jetting can be accomplished using a drilling rig to push drill rods and jets into the well or by pulling a jetting tool into the well using a cable. Because this technique requires tools inside the well, it is typically more time consuming and more expensive.

How do I choose the right drilling mud system?

The best way to choose the right system is to work with your driller to evaluate the alternatives. Drilling mud is necessary to cool the drillhead and to remove cuttings from the borehole. The ideal drilling mud has the ability to suspend solids, flow easily, maintain the borehole and lubricate the materials to be installed.

How do you install a hollow bar micropile?

Hollow bar micropiles are installed self-drilling, typically using a large-diameter drill bit. Installation is accomplished with rotary or rotary-percussive drilling equipment, depending on the ground conditions and the intended installation length. Filling/grouting of the borehole is either performed simultaneously while drilling or afterwards.