Abstract: Drilling apparatuses and methods for limiting precession are provided. According to one embodiment, a drilling apparatus includes a non-rotating stabilizer. The non-rotating stabilizer includes a first blade and a second blade, the first blade being arranged opposite the second blade. The first blade is biased radially outwardly by a force of a first value. The second blade is not biased radially outwardly by a force corresponding to the first value. The second blade may be a blade which is slidable along the non-rotating stabilizer in an axial direction and allow free sliding axial contact with the formation.

Abstract: Drilling apparatuses and methods for limiting precession are provided. According to one embodiment, a drilling apparatus includes a non-rotating stabilizer. The non-rotating stabilizer includes a first blade and a second blade, the first blade being arranged opposite the second blade. The first blade is biased radially outwardly by a force of a first value. The second blade is not biased radially outwardly by a force corresponding to the first value. The second blade may be a blade which is slidable along the non-rotating stabilizer in an axial direction and allow free sliding axial contact with the formation.

Abstract: A method and apparatus for recomputing an optimum path between a present location of a drill bit and a direction or horizontal target uses linear approximations of circular arc paths. The technique does not attempt to return to a preplanned drilling profile when there actual drilling results deviate from the preplanned profile. By recomputing an optimum path, the borehole to the target has a reduced tortuosity.