Baker Hughes Inc. announced the availability of its StayCool™ multidimensional cutter, which helps operators drill to total depth faster and more cost effectively by extending cutter life and footage per run. Used exclusively on the Hughes Christensen Talon™ platform of premium polycrystalline diamond compact bits, these cutters incorporate a contoured diamond table, wear-resistant diamond materials, and new interface designs.
“Historically, operators would design more cutters into a bit to compensate for cutter wear or damaged cutters, which isn’t always the most efficient way to drill,” said Scott Donald, vice president of Drill Bits for Baker Hughes. “The StayCool cutter allows us to offer a bit that maintains the same cutter density but can perform better when cutters are worn.”
In challenging environments such as interbedded sandstones and carbonates, bit performance is directly related to cutters and their ability to withstand heat. Overheated cutters experience abrasive wear faster, which can lead to lower rates of penetration (ROP) and higher mechanical specific energy (MSE) or wasted energy that is not directly transferred into removing rock.
In the Cana Woodford field of Oklahoma, this technology provided customers with a 10% improvement in ROP and a 37% improvement in footage when drilling through hard sands interbedded with hard limestones.
“The [StayCool] cutter in the Devon Cana field has given us better penetration rates in the variable changes of formation, and allowed us to have longer bit hours; thus, lowering the overall cost per foot,” said TerryWilhoit, drilling consultant for Devon Energy.
“StayCool cutters require less weight and energy input to drill the formations at the desired ROP. The cutters continue drilling long after the standard cutters slow down due to wear. These cutters save time and money by reducing the number of bit trips,” adds Justin Mullinax, drilling engineer for Devon Energy.
In the Pinedale anticline of southwestern Wyoming, StayCool cutters are being used to drill through abrasive sandstones interbedded with shale. In this area, the Talon bit with StayCool cutters has improved the distance drilled by 12% in 50 runs totaling 156,000ft. StayCool cutters have already drilled more than 289,000ft in 89 runs, in five different applications in field tests, and for more than 20 customers throughout the United States.
The StayCool cutter’s patent-pending contoured design reduces friction, maintains a sharper cutting edge throughout the bit run, and reduces MSE. Laboratory testing has shown that the cutters generate 20% less heat on the cutter face than conventional flat-surface cutters. Less heat minimizes cracking tendencies on the diamond table that can lead to failures and shorten run life. As a result, run lengths are extended, and the cutters remain aggressive while enabling the bit to maintain higher ROPs throughout the bit run.