Oil sands applications are well known to be one of the most demanding drilling environments in the industry with regard to durability. The bodies of the cutters and the body of the bit experience severe wear in these applications, leading to inconsistent drilling performance. Extensive efforts in the past decade to solve this issue have been met with limited success. In oil sands applications, the sands are highly abrasive and unconsolidated. The result is that the sand particles quickly become suspended in the drilling fluid and mimic the effect of sandblasting the bit for the duration of the run. In many cases, the bit body wear around the cutters is extensive enough to cause premature bit failure due to cutter loss. The bodies of the PDC cutters themselves also suffer extreme material loss, which leads to cutter breakage and an associated reduction in drilling performance. Finally, in the lateral interval, the sands in cutting beds lying on the low side of the hole cause serious wear to both the gage and backreaming portions of the bit.

This paper will discuss new technologies that have proven to eliminate bit wear in the horizontal reservoir interval. Comparisons will be made detailing the severe wear experienced with conventional bits and the absence of wear experienced with identical bit designs using a new body construction technology. A novel PDC cutter will also be presented that has been developed to eliminate cutter body wear.

The requirements for improving drilling performance in oil sands applications are as unconventional as the wear experienced in these applications. Unlike traditional applications where improving performance includes an effort to drill faster or further, oil sands applications are typically control drilled and the entire interval is almost always completed in one run. The focus in these applications to augment performance is to improve directional control, enhance backreaming efficiency and hole quality, and increase bit durability. The new technologies detailed in this paper have proven to dramatically enhance each of these key performance indicators, resulting in the ability to drill further and faster, while improving the possibility of success of the well completion.

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