Published: 10/07/2014
Published: 10/07/2014
An operator planned to drill a 12 1/4-in vertical section in the Browse basin offshore Australia through the challenging Dampier, Heywood, Baudin Marl, and Wollaston Formations. These formations are composed of interbedded hard limestones and chert with high compressive strengths, which induce heavy damage to conventional PDC bits. Such damage slows ROP and requires the operator to pull bits prematurely, requiring more time to drill the section.
To improve bit durability and ROP, Smith Bits, a Schlumberger company, recommended using StingBlade bits. Engineers used the IDEAS platform to determine the optimal placement of Stinger elements across the bit face. The Stinger elements’ 3D conical shape is designed to fail high-compressive-strength rock with a concentrated point load. The elements also have a thicker diamond layer for maximum strength and durability. This enables StingBlade bits to drill farther through formations that typically cause impact damage to PDC bits while also sustaining higher ROP throughout the run.
The first StingBlade bit drilled 1,516 m at 11 m/h, equaling 97% more footage than the best run in the same section of the offset well. ROP also improved by 57% in this run. The second StingBlade bit drilled the remaining section to TD at an average ROP of 16 m/h. Altogether, the two StingBlade bits helped the operator save more than 5 days of drilling time.
Challenge: Drill 12 1/4-in vertical section through formation known to induce excessive damage on conventional PDC bits, causing short footage runs and low ROPs.
Solution: Use StingBlade conical diamond element bits to drill through interbedded hard limestone with high chert content; place Stinger conical diamond elements across the bit face using the IDEAS integrated drillbit design platform to ensure maximum durability for longer runs with high sustained ROP.
Results:
