Case Study: Driver^® Tools Reduces Stick-Slip

Summary

Two 7” Driver® tools were run in a Rotary Steerable Assembly as a trial to improve weight transfer to the bit, and also to reduce vibration & Stick-Slip within the BHA. The 8 ½” section goal was to drill from the 9 5/8” casing shoe at 9,820’, building from 78° to horizontal, before initiating an 87° left turn, whilst holding horizontal to section TD at 16,569’. A new M222 PDC bit was utilised, consistent with the offset wells.

Test Results

The 6,740’ section was successfully drilled in 96.7 hours, with a drilling ROP of 69.6ft/hr. Offset ROP’s varied between 57ft/hr to 78ft/hr. A significant reduction in Stick-Slip was measured at the LWD tool, with severe Stick-Slip held below 2% for the entire section. The best offset run had measured Severe Stick-Slip, with intervals in excess of 30 minutes, for 20% of the 8 ½” section. Bit grading revealed Worn Cutters on the Driver® assembly bit, compared to chipped teeth witnessed on the offset runs; suggesting improved consistent WOB.