Published: 02/22/2016
Published: 02/22/2016
While pad drilling in the Texas portion of the Anadarko basin, Unit Petroleum Company sought to improve single-run ROP in the 8 3/4-in intermediate section for future offset wells in the area. The interval to be drilled is primarily shale with harder interbedded layers of sandstone and limestone, with unconfined compressive strength (UCS) range of 3,000 to 15,000 psi.
Using a directional motor, the operator wanted to drill the intermediate section to the kickoff point at the top of the targeted Granite Wash formation. Because of nearby wells on the pad, the interval to be drilled typically included a slight nudge.
On an offset well approximately 5 miles from the planned Mahler 108-1H well, Unit Petroleum drilled the 8 3/4-in intermediate section using an 8 3/4-in MSi616PX premium PDC bit from Smith Bits. From 5,545 to 9,115 ft, the operator achieved an ROP of 75.16 ft/h, and the bit exhibited relatively minimal cutter wear (1-1-WT).
To increase ROP over the offset well when drilling Mahler 108-1H, Schlumberger suggested that Unit Petroleum deploy an AxeBlade bit for instantaneous ROP improvement. An 8 3/4-in bit with ridged diamond elements was selected to enable faster speeds and improve directional control through higher frontal impact resistance and increased cutting efficiency.
The aggressive geometry of the unique ridge-shaped element achieves at least 22% deeper penetration than conventional PDC cutters at the same drilling parameters. Additionally, the ridged diamond elements enable less overall torque and fewer torque fluctuations for smoother drilling operations. With better toolface control, the AxeBlade ridged diamond element bit achieves better ROP, especially in directional drilling operations.
Prior to drilling, an analysis using the IDEAS integrated drillbit design platform determined that the AxeBlade bit would provide enhanced cutting efficiency through instantaneously increased ROP and lower drilling torque compared with the premium PDC bit used on the previous well. Once drilling began, Schlumberger provided directional drilling services for the well.
Unit Petroleum drilled the Mahler 108-1H well’s intermediate interval from 5,918 to 9,047 ft in a single run at an ROP of 95.54 ft/h, a 27% increase over the offset well. Under similar drilling parameters and using the same cutting structure layout, the AxeBlade bit not only increased ROP but generated 20% less surface torque and impressive dull condition. This improved drilling performance saved the operator 14.75 hours of rig time. The higher ROP enabled by the bit means that the operator can finish the well sooner and reduce the cost of operations.
Challenge: Improve ROP and reduce torque while drilling through interbedded formations of shale, sand, and limestone above the Granite Wash in the Anadarko basin.
Solution: Deploy AxeBlade ridged diamond element bit to drill the intermediate section.
Results: Drilled the entire interval at 27% higher ROP and generated 20% less torque.
