Abstract: A turbine drilling assembly can include a turbine drilling motor having an upper drill string connector, and an inclination sensor positioned in the turbine drilling assembly below the upper drill string connector. Another turbine drilling assembly can include a turbine drilling motor having an upper drill string connector, a sensor positioned in the turbine drilling assembly below the upper drill string connector, and a transmitter which transmits sensor data through a housing of the turbine drilling motor.

Abstract: A drilling motor assembly can include a housing, a shaft, and a pawl which selectively engages a recess, the pawl having an axis of rotation and a generally planar engagement face which engages a generally planar engagement face of the recess when relative rotation between the housing and the shaft is prevented. The engaged engagement faces can be oblique relative to a radius extending from the axis of rotation to the engaged engagement faces. A method of drilling a wellbore can include flowing a fluid through a drilling motor assembly, thereby rotating a shaft relative to a housing, and rotating the housing, thereby engaging a pawl with a recess and preventing relative rotation between the housing and the shaft, the pawl and recess each having a generally planar engagement face, whereby the engaged engagement faces prevent relative rotation between the shaft and the housing.

Abstract: A drilling motor assembly can include a housing, a shaft, and a pawl which selectively engages a recess, the pawl having an axis of rotation and a generally planar engagement face which engages a generally planar engagement face of the recess when relative rotation between the housing and the shaft is prevented. The engaged engagement faces can be oblique relative to a radius extending from the axis of rotation to the engaged engagement faces. A method of drilling a wellbore can include flowing a fluid through a drilling motor assembly, thereby rotating a shaft relative to a housing, and rotating the housing, thereby engaging a pawl with a recess and preventing relative rotation between the housing and the shaft, the pawl and recess each having a generally planar engagement face, whereby the engaged engagement faces prevent relative rotation between the shaft and the housing.

Abstract: A turbine drilling assembly can include a turbine drilling motor having an upper drill string connector, and an inclination sensor positioned 10 in the turbine drilling assembly below the upper drill string connector. Another turbine drilling assembly can include a turbine drilling motor having an upper drill string connector, a sensor positioned in the turbine drilling assembly below the upper drill string connector, and a transmitter which transmits sensor data through a housing of the turbine drilling motor.

Abstract: A stabilization device for a down-hole motor for use in drilling operations for example in oil-fields to control any tendency for spiralling of the tool bit during the drilling action and to permit steering by a "orientate and rotate" technique. In an example of the device, an end portion of a motor shaft (26) projects from a motor body (20), the projecting portion being comprised of an attachment apparatus or bit box (28) by which a tool bit (38) is connected for rotation. The bit box (28) may be separable from the shaft (26) or may be integrally formed therewith, but, is provided with a stabiliser means (32) in the form of part-helical vanes surrounding the bit box (28). The bit (38), when secured in the box (28), is located immediately adjacent the stabilising vanes (32) for maximum control; additionally, stabiliser vanes (22,24) may be provided on the motor body portion (20) and, if required, on the selected tool bit.