Apparatus for drilling colinear holes through concentric pipes

A method for forming a hole through concentric pipes, comprising:

• placing a clamp adapted for enclosing an outside pipe, the clamp having an inside diameter and a door sized to pass the outside pipe into the clamp, around the outside pipe and operating adjustable devices disposed at selected positions around the inside diameter of the clamp to hold the clamp to the outside pipe;
• providing a pair of drilling assemblies and bits, each of the drilling assemblies being attached to the clamp and comprising a hydraulic motor and a mechanism for connecting the motor to the bit, the bit having an axis for drilling, and a carriage, the carriage having a rigid slidable support and being driven along the support by hydraulic apparatus, the rigid slidable support being disposed such that the axes for drilling of the bits are colinear and in opposite directions;
• providing a pair of control modules for the drilling assemblies and hydraulically connecting a control module to at least one of the drilling assemblies;
• and
• providing hydraulic power to at least one of the hydraulic motors and the hydraulic apparatus and operating at least one of the control modules so as to form at least a part of the hole through the concentric pipes.