Patent ID: 7159674

Claim:
Method of directional drilling of a hole, for which is used a drill support in the form of a flexible continuous drill tube with proximal end and distal end, that at the end of the drill support's distal end is connected a bottom hole assembly comprising a drill machine and a percussion tool acting on a drill bit for forming a drill string, which is fed into the gradually formed hole, the method including: indexing the drill bit while drilling is in progress by gradually rotating around its axis between each blow of the drill bit, performing the indexing in the area between the drill support's distal end and the drill bit, the indexing taking place when the drill bit is moving away from a rock surface or being in its retracted position, carrying out the indexing using a rotatable fluid activated motor, a liquid driving fluid for which is fed via a passage that extends through the drill support; and controlling the direction of the drill bit relative to the drill support using a controller including a motor adjustable joint, said bottom hole assembly including said controller.