Directional Drilling Technologies

Task Description

This task involves the adaptation of four petroleum and utility indus-
tries directional drilling methods for application to environmental restoration activities. The use of directional wells allows the reme-
diation of areas not generally accessible by vertical drilling methodology and increases the efficiency of a variety of remedia-
tion, characterization, and moni-
toring activities (Photo 2.1a).

In addition, it allows remediation activities to be performed without generating new contaminant path-
ways into unperturbed ground-
water- bearing horizons. Techno-
logies that were also demonstrat-

ed and evaluated utilizing the seven horizontal wells that instal-
led during this task include in situ air stripping, bioenhancement for in situ bioremediation through injection of nutrients, and in situ radio frequency heating. They are described in separate sections. The four tested drilling techno-
logies are:

Short-Radius Drilling (SRD)

The basic equipment for this type of directional drilling is essentially the same as would be used for the installation of a vertical recovery or monitoring well. The borehole is drilled vertically using a non-steerable drill bit to the point where it needs to be deviated to achieve the desired configuration. At this point a wedge-shaped