M/D Totco’s™ Twister™ automated drillpipe oscillator is designed to rotate the pipe back and forth when the directional driller slides. The software enhancement keeps the pipe in rotation, resulting in a more efficient transfer of weight on the bit and improved performance of directional BHAs without adding costly pieces of equipment. Accessed from the Top Drive screen on the HMI, the driller can choose Bump, Follow, or Rock modes from an intuitive interface, allowing for precise toolface orientation or induce RPM oscillations in the drillstring to reduce the static friction that occurs during sliding operations. The addition of Twister’s automated feature results in a considerably higher sliding ROP, better wellbore quality, reduced days to drill, and cost savings.
Bump Mode – Drill Bit Face Orientation
Bump mode rotates the top drive shaft a fixed distance in one direction. The driller can choose Bump clockwise or Bump counterclockwise, depending on the desired direction. The top drive then smoothly rotates the shaft the desired distance in a specified direction.
Follow Mode – Drill Bit Face Orientation
Follow mode gives the driller very fine control of the TDS model top drive shaft, and is best suited for bit-face orientation. In this mode, the top drive shaft follows the driller’s commands from the Amphion™ chair’s rotary encoder. This mode give very accurate and fine control of the shaft in both clockwise and counterclockwise directions.
Rock Mode – Drill String Friction Reduction
Rock mode rocks the drill string in a preset direction using a specified amount of energy, then reverses direction, and rotates back to the original position. This allows for maximum weight transfer as friction is broken while maintaining the toolface.
Features and Benefits
- Keeps pipe in rotation during slide drilling, resulting in more efficient transfer of weight to the bit
- Energy setpoint system allows for a dynamic number of wraps to be applied during a slide
- Ensures the right number of wraps are applied to maximize the breaking of friction while minimizing the risk of unwanted toolface movement
- Result is a considerably higher sliding ROP and a better quality wellbore, from an easy to use interface