New Steel PDC Drill-Bit Technology Redefines Performance Standards in Key Natural-Gas Applications

One of the biggest ongoing challenges to the successful production of many hard, interbedded and abrasive applications is the ability to improve drilling efficiency. In many of these applications, the use of PDC drill bits has been sporadic as many formations have been labeled 'not PDC drillable'. As a result, these intervals often include several trips to change out drill bits (both rollercone and PDC drill bits of different types) in an attempt to maximize drilling performance. While PDC drill bits have generally proven to drill with higher ROP than rollercone bits, in these difficult drilling environments, the ROP differential can be very small, and the durability differential can be very large. A new line of steel bodied drill bits has recently been introduced that has shown dramatic improvements in drilling efficiency in highly difficult Western Canadian drilling applications. These new steel bodied drill bits incorporate a second row of PDC cutters to add durability to the bit while still remaining aggressive enough to drill at a high ROP. The use of steel as a body material makes it possible to have the best of both worlds - a bit with very high diamond volume for excellent durability (two rows of PDC cutters per blade) while also achieving a high void volume and large junk slot area for excellent cleaning. New techniques have also been developed to protect the steel body from the typical erosion and wear that has historically been seen in highly abrasive applications. Recent runs with this new line of drill bits have been recorded in intervals and through formations previously only drilled with rollercone bits. The new technology developed for these bits allows higher ROP and longer runs in demanding applications. In one challenging well in British Colombia, a series of these new steel multi-row bits drilled nearly twice as fast and over 30% more footage per bit than a direct offset well - saving days off the drilling curve. Introduction: The field of study is located deep in the Rocky Mountains of Northeast British Columbia, Canada, and has a reputation of being a very challenging area to drill. As a result of these difficulties, activity in the area has been relatively low as the economics of production in the area were less than ideal. Historically, the wells in this area were primarily vertical or low-deviation wells targeted at gas production in the Halfway. Recent work, however, has proven that deep horizontal wells through the Montney are showing much greater returns than the earlier Halfway wells. While the addition of the horizontal component has obviously added expense to the drilling program, with advances in drilling performance, the applications have become more attractive economically and have sparked the interest of many operators in the area. Future activity in the region is strong.

Multi-Row Steel PDC Drill Bit Technology Redefines Performance Standards in Hard, Interbedded, and Abrasive Applications

Beaton¹,

Krooshoop²,

Herman³

2008

New Technologies Eliminate Drill Bit Wear in Oil Sands Applications

Beaton¹,

Cyre²,

Isnor³

et al. 2013

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.

Paradigm Shift in Egypt's Western Desert: Premium Grade Steel-Body Bits Displacing Matrix Designs in Key Applications

Kamel¹,

Mansour²,

Ibrahim³

et al. 2015

Recent manufacturing and hardfacing advances have produced a steel-body PDC bit (SB-PDC) capable of efficiently drilling interbedded formations at significant depth. These technological advances have increased the bit's resistance to abrasion/erosion and enabled a new style steel-body PDC bit to drill formations in Egypt's western desert previously drilled by matrix PDC bits. Field tests have confirmed the steel-body PDC bit can outperform matrix PDCs in a wide-range of interbedded applications that contain a heterogeneous mixture of shale, sand/siltstone, and limestone. The approach combines optimized cutting structure design and premium PDC cutters that enable the steel-body PDC bit to drill the abrasive sand/siltstone component. The bit can also efficiently drill shale and soft limestone due to its hydraulic efficiency which was a factor limiting performance improvement in previous designs. The bit solution employs: ➣Cutting structure optimized using FEA-based modeling system➣Premium grade PDC cutters➣Next generation of abrasion/erosion resistant hardfacing material➣Hydraulically efficient bullet-shaped body type The new SB-PDC technology was deployed in a sequence of tests in different applications and fields in Egypt's western desert. The trials were run in different lithologies at different depths. Direct comparisons to relevant matrix PDC technology and other available steel-body bits clearly demonstrates the new-style steel-body PDC bit's value by setting new benchmarks and reducing cost/ft.