BOREHOLE GUIDE

摘要

A borehole guide for drilling interpenetrating boreholes which may be parallel to one another or inclined to one another. The borehole guide is clamped in position in an already drilled borehole by inflating an inflatable member. Thereafter a drill which is directed by the guide is used to drill a second borehole which overlaps the first hole. A number of the borehole guides may be used end to end, and their relative orientation may be varied to direct the second borehole, within limits along a desired path.