Halliburton announced the release of Stega efficient layout design, an advanced drill bit that optimizes the placement of back-up cutters to improve bit durability without decreasing drilling efficiency or rate of penetration (ROP).
Traditional back-up cutters on polycrystalline diamond bits have many limitations such as increased heat and wear, poor bit cleaning and reduced ROP. To overcome these challenges, Halliburton designed the Stega bit with offset back-up cutters placed 180 degrees or more from the primary cutter. As a result, the new layout enhances durability with less cutter wear while maximizing drilling efficiency compared to traditional dual row or single row cutting structures.
"The development of Stega provides operators with the latest energy-efficient layout methodologies for targeted applications," said Scott Regimbald, vice president of Drill Bits and Services. "The advantages translate to extended bit life with no loss of ROP to help operators drill longer and faster while reducing costs."
As cutters wear, more engagement area is exposed to rock and this increased area reduces cutting efficiency. A large portion of energy is lost as friction from the increased contact area takes away from the bit's ability to shear rock. Increased friction translates to heat culminating in a vicious cycle of rapidly increasing wear. Stega breaks this cycle by taking advantage of the bottom-hole pattern already created and removing load from the primary cutter before rapid acceleration of wear begins.
An operator in West Texas deployed the Stega bit in a harsh drilling application that historically used traditional non-Stega bit designs. Compared to the best performance of the non-Stega layouts, the Stega bit drilled approximately 40 percent (2,400 feet) further at an ROP that was 19 percent (15 feet) per hour faster. This resulted in valuable rig-time savings.