Abstract: A steerable drilling system comprises a rotary drill bit 14 secured to a housing 16, a secondary rotary drill component 22 carried by the housing and rotatable therewith, the second rotary drill component 22 having a gauge dimension greater than that of the rotary drill bit 14, and a drive arrangement operable to displace the secondary rotary drill component 22 relative to the housing 16 while maintaining an axis 24 of the secondary rotary drill component 22 substantially parallel to an axis 18 of the housing 16.

Abstract: A method for displaying a formation model while drilling a wellbore in the formation includes operating a well logging instrument at a measurement point in the formation along a wellbore while the wellbore is being drilled. Measurement data regarding the formation are obtained from the well logging instrument. An actual orientation of a geological structure is determined from the measurement data. A trajectory of the wellbore is displayed in three dimensions as it is being drilled through the formation. While drilling the wellbore, the geological structure is displayed along the trajectory of the wellbore according to the determined actual orientation of the geological structure. The actual orientation reflects an azimuth angle of planes corresponding to the geological structure. The trajectory of the wellbore is changed in response to displaying the determined actual orientation of the geological structure relative to the trajectory.

Abstract: A method for displaying a formation model while drilling a wellbore in the formation includes operating a well logging instrument at a measurement point in the formation along a wellbore while the wellbore is being drilled. Measurement data regarding the formation are obtained from the well logging instrument. An actual orientation of a geological structure is determined from the measurement data. A trajectory of the wellbore is displayed in three dimensions as it is being drilled through the formation. While drilling the wellbore, the geological structure is displayed along the trajectory of the wellbore according to the determined actual orientation of the geological structure. The actual orientation reflects an azimuth angle of planes corresponding to the geological structure. The trajectory of the wellbore is changed in response to displaying the determined actual orientation of the geological structure relative to the trajectory.

Abstract: A method for displaying a formation model includes displaying a trajectory representing a three-dimensional structure of the wellbore; and displaying objects representing a bed boundary along the trajectory, wherein the objects are displayed at distances from the trajectory according to measurement data, wherein the objects are displayed in orientations reflecting azimuth angles of planes corresponding to the bed boundary.

Abstract: A steerable drilling system comprises a rotary drill bit 14 secured to a housing 16, a secondary rotary drill component 22 carried by the housing and rotatable therewith, the second rotary drill component 22 having a gauge dimension greater than that of the rotary drill bit 14, and a drive arrangement operable to displace the secondary rotary drill component 22 relative to the housing 16 whilst maintaining an axis 24 of the secondary rotary drill component 22 substantially parallel to an axis 18 of the housing 16.

Abstract: A method for displaying a formation model includes displaying a trajectory representing a three-dimensional structure of the wellbore; and displaying objects representing a bed boundary along the trajectory, wherein the objects are displayed at distances from the trajectory according to measurement data, wherein the objects are displayed in orientations reflecting azimuth angles of planes corresponding to the bed boundary.