Schlumberger married its rotary steerable system (RSS) technology with its electromagnetic pulse telemetry in a seven-well pilot program sponsored by BP in the San Juan Basin of Colorado and New Mexico. The systems used included PowerDrive X5, PowerDrive vorteX, PowerDrive vorteX running PowerV rotary steerable systems and E-Pulse XR measurement while drilling (MWD).

This technology was used in the world’s first well drilled directionally using 31¼2-in. coiled tubing. BP was able to prove that 8 3/4-in. boreholes could be drilled reliably and efficiently in vertical, slanted and S-well configurations.

The use of a rotary steerable system provides all of the advantages of rotary steerable directional drilling to an inherently sliding system. It results in a smoother trajectory borehole and drilling penetration rates that meet or exceed standards set with conventionally drilled offsets, largely due to the reduction in orienting time, the elimination of connection-time and significantly faster trip times.

In vertical sections, the PowerV control senses any deviation from vertical and automatically compensates for it. Use of the system resulted in closures of less than 1 ft (.3 m) at the bottom of the vertical section, compared to 90.5 ft and 85.3 ft (27.5 m and 26 m) for two previously drilled wells where PowerV was not used. In build-up sections, downlink commands are pulsed to the tool with the bit off bottom for maximum build-up rate, but in tangent or drop sections, commands can be sent while drilling ahead in the form of a toolface direction and steering percentage. This removes the need for orienting a bent housing motor or the requirement for electrical or hydraulic orienting devices.

Critical MWD data was continuously transmitted using E-Pulse XR telemetry. Destructive bit vibration can be all but eliminated because triaxial vibration data are continuously sent to surface so the driller can take immediate corrective action. Stick-slip vibration was eliminated by using the PowerEdge power section.