Turbines
A turbine is made up of several sections:
• Drive stages or motor section.
• Axial thrust bearing assembly and radial bearings.
• Bit drive sub.
As stated earlier, the drive stages, or motor section, consists of a series of
stators and rotors of a bladed design. This stator and rotor combination
form a stage. Turbines are referred to as 90 stage, 250 stage, etc. The
number of stages determines the torque generated. Each stage,
theoretically, applies an equal amount of torque to the control shaft and it is
the sum of those torques which will be output to the bit.
The drive sub is simply the bit connection and bearing shaft. Radial
bearings protect the shaft from lateral loading and the thrust bearings
support the downwards hydraulic thrust from mud being pumped through
the tool and the upward thrust of weight being applied to the bit.
Theoretically, weight on bit should be applied to equalize the hydraulic
thrust, which unloads the bearings and prolongs their life.
A turbine is made up of several sections:
• Drive stages or motor section.
• Axial thrust bearing assembly and radial bearings.
• Bit drive sub.
As stated earlier, the drive stages, or motor section, consists of a series of
stators and rotors of a bladed design. This stator and rotor combination
form a stage. Turbines are referred to as 90 stage, 250 stage, etc. The
number of stages determines the torque generated. Each stage,
theoretically, applies an equal amount of torque to the control shaft and it is
the sum of those torques which will be output to the bit.
The drive sub is simply the bit connection and bearing shaft. Radial
bearings protect the shaft from lateral loading and the thrust bearings
support the downwards hydraulic thrust from mud being pumped through
the tool and the upward thrust of weight being applied to the bit.
Theoretically, weight on bit should be applied to equalize the hydraulic
thrust, which unloads the bearings and prolongs their life.
