Curve ROP improved by 53.4% compared to the average curves in previous wells
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Identify unique drill bit solution to improve steerability in curve section
Middle East
During an ongoing drilling campaign, an operator faced challenges with the optimization of a single bottomhole assembly (BHA) run performance in the 8.5 in. vertical, curve, and lateral sections from ~7,500 to 18,000 ft. They used a rotary steerable system (RSS) while drilling through interbedded carbonate layers.
The 1,800 ft curve section builds from 0 to 90° at an average build rate of 6 to 7°/100 ft. In addition, this section involves drilling across four formation layers with a dropping tendency constraint, and with relatively low rock strength values (approximately 12 to 15 kpsi). The control of the rate of penetration (ROP) is critical to achieving optimal build rates per directional plan, even if it results in reduced ROP.
The operator challenged Halliburton to develop a unique solution that improves steerability in the curve without compromising stability and performance in the vertical and lateral sections. Each section presents distinct challenges, including vibration mitigation in the vertical, build rate targets in the curve, and effective weight on bit (WOB) transfer in the lateral. Drill bit design plays a crucial role in the review of these challenges because stability in the vertical and lateral often involves trade-offs with lateral efficiency in the curve. The balance of these trade-offs can limit performance advancement in this application.
One key factor that influences lateral aggressiveness in an RSS is the bit-to-pad distance. A shorter distance from the bit to the pad allows a more effective transfer of applied side force to the bit. Thus, Halliburton combined the HyperSteer™ 8.5 in. GT65RHs directional drill bit and the iCruise® X intelligent RSS. This approach shortened the bit’s make-up length (MUL) without compromising critical design features, such as gauge length and bit profile.
With the elimination of the traditional shank that connects the bit to the drill string, the HyperSteer shankless bit provides a direct and responsive connection between the drill bit and the drilling assembly. This design enhances the bit’s ability to quickly respond to changes in directional and steering commands and helps improve steerability. In addition, increased gauge pad length improves stability without a MUL increase.
The engineered solution delivered effective build rates in the curve section without parameter control. As a result, the curve ROP improved by 53.4% compared to the average curves in previous wells. The use of these scientific principles with the HyperSteer directional drill bit design led to enhanced drilling performance and operational efficiency. The operator expressed satisfaction with the curve performance due to a significant ROP improvement compared to previous ultimate recovery wells in the region.