TotalEnergies reduced uncertainty by 7 m at 5,345-m TD

Summary

TotalEnergies pinpointed well spacing in a complex field and reduced the overall ellipse of uncertainty by an estimated 25% with new gyro technology. High-accuracy surveys increased the confidence to drill additional wells.

Objective

Because the location contained many wells, one of the main concerns was avoiding collision. TotalEnergies also wanted to reduce invisible lost time by proactively identifying tight spots to decrease the number of adjustments during drilling. Additionally, TotalEnergies sought to increase the size of the drilling tunnel to provide more space for drilling a lower tortuosity wellbore and reducing downlink commands to improve the rate of penetration (ROP).

Results

TotalEnergies selected GyroLink™ definitive gyro-while-drilling service because of its capability to survey from three axis points, enabling a greater understanding of potential collision and more precise well spacing. The service also includes MicroGuide™ high-resolution tortuosity log, which delivers real-time identification of tights spots for TotalEnergies to optimize pull out of hole operations and guide the casing program.

To further reduce surveying uncertainty, TotalEnergies combined the surveys of the GyroLink service, which take no rig time, with the continuous six-axis surveys of the TruLink™ definitive dynamic survey-while-drilling service. The combined services reduced the ellipse of uncertainty compared with conventional gyro-while-drilling (GWD) techniques. This reduction enabled a significant increase in the drilling tunnel size—a difference of 5 m over a 1,000-m section for the directional driller to drill through.

Even in a very congested field for drilling, TotalEnergies passed a 9⅝-in casing joint through a 12¼-in diameter hole with a maximum bend of 2.74°/30 m at a depth of 1,887 m. In a complex drilling profile such as this, precision drilling was necessary.

GyroLink service decreased lateral uncertainty 12%, by 7 m at TD (5,345 m). A 25% overall reduction in the ellipse of uncertainty was anticipated for other sections of the well. The reduced ellipse of uncertainty resulted in fewer downlink commands, which improved ROP. TotalEnergies diminished collision risk, improved clearance, and pinpointed well spacing for optimal well construction efficiency.

Graph of larger ellipse of uncertainty for conventional gyro surveys compared with GyroLink survey.

GyroLink service reduced the ellipse of uncertainty by 7 m at TD (5,345 m) compared with conventional gyro-while-drilling techniques (2.8 sigma confidence level).

GyroLink service’s 3D well profile indicates measured depth markers along the well and maximum diameter. (Casing diameter and horizontal displacements are not to scale.)

GyroLink and TruLink are marks of SLB.
MicroGuide is a mark of Gyrodata, Inc.