Improve ROP and maintain steerability in lateral and curve sections

Shell was drilling four directional shale wells in Neuquén, Argentina that were characterized by low compressive strengths. Each one had a curve in the Quintuco formation with a lateral in the Vaca Muerta formation.

The two wells in the Sierras Blanca block were drilled using first-generation Spear shale-optimized steel-body PDC drill bits on a conventional downhole motor with the curve and lateral drilled separately.

The first well was drilled using an SDi513 Spear bit on a PowerDrive Archer high build rate RSS assembly with both sections completed by the same bit in one run. In the second well, the operator wanted to drill an 8.5-in interval from surface casing at 2,668 m to a TD of 4,078 m in one run. To achieve that goal, the operator had to improve ROP in the lateral and maintain bit steerability in the curve.

Optimize drilling performance with large cutters and enhanced hydraulic features

To maximize bit performance, Schlumberger recommended the next-generation Spear SDi516 bit with five blades and 16-mm cutters. The larger and more aggressive cutters allowed for takeoff in the lateral and a smooth toolface control for the curve. In addition, the bit was designed using a cutter and gauge configuration optimized for the PowerDrive Archer RSS. The customized design ensured smooth sliding and improved rotating capabilities while building the curve and maximizing ROP in the lateral.

Furthermore, the SDi516 differentiates itself from its predecessor with two enhanced hydraulic features: shale evacuation channels and a super bullet body design. These features significantly reduce drill time by combating factors that slow down operations such as long lateral sections and low hydraulic horsepower caused by poor pumping capabilities.