The present invention relates to a stabilizer tool to be used in oil well drilling. This drill string tool is typically mounted in the lower part of a drill string and is rotated by adding a rotating force to the drill string from the surface or by actuation of a down hole motor. The rotating drill bit produces a borehole at a diameter equal to the drill bit as the drilling proceeds downward. In many cases, earth formation can be relatively soft or subject or suffers a geometrical change. This change may take place due to absorbing moisture from the drilling mud. In such cases earth formation swells and closes on the drill string, choking the drill string rotary movement and producing potentially damaging torque. The present invention provides a hole reaming tool that has: - A body contains a through bore for passing drilling fluid.

- Outside of said body, it has a lower tapered part that holds hard reaming carbide buttons to ream the hole back to size. Above the tapered part is a straight stabilizing part which constrains and holds the drill string steady during the drilling operation.

The invention relates to a vibration damping Reamer to be used in stabilizing of oil well drilling tools during operation. The vibration damper (1) is an arrangement that will damp vibrations arising from drilling using rotary drill bit. The said tool with two axially spaced gauged sections (2) and (3) cleans and gauges the hole to size using carbide buttons inserted on the tool side (4). The second function is to keep the drill stem in the centre of drilled hole. By stabilizing the drill stem inside the hole and keeping it in the hole centre, the stabilizer extends the life of the drill bit, cuts down on vibration by minimizing the possible undesired lateral movements of the drill stem while drilling. This tool is threaded at the bottom into the drill bit and at the top into the drill stem.

An apparatus for the directional drilling of a bore hole through a solid substrate includes a main bore head (2) mounted for rotation on a flexible main drive shaft (10) The apparatus includes elongate tensioning means (30) extending axially along the flexible drive shaft (10) substantially from the main bore head end of the drive shaft (10) towards a driven end of the drive shaft (10), and tension in the tensioning means (30) tends to urge the flexible drive shaft (10) to bend, thereby altering the drilling direction.

A drill bit including a bit body and a plurality of blades formed in the bit body. The blades are formed, at least in part, from a base matrix material that on one embodiment is impregnated with abrasive particles. One side of the bit is formed, with respect to its axis of rotation, to a smaller radius than the opposite side of the bit. The asymmetry of the bit enables the bit to drill a larger diameter hole than a pass through diameter of the bit. The opposite side defines a contact angle between the bit and a formation. In one embodiment, the contact angle is at least 140 degrees.. In one embodiment, a plurality of inserts may be located on the blades to provide gage protection. In another embodiment, the bit may also include a gage sleeve that helps keep the bit stabilized in the wellbore.