Auto-curve technology drilled 1,500 m at 2°/30-m DLS

Summary

Using the rotary steerable system (RSS) auto-curve capability, an offshore Brazil operator reduced downlink commands by 33% and improved net rate of penetration (ROP) by 38%. Increased drilling efficiency enabled a reduction in total drilling time by 17 hours compared with the perfect well time in this field.

Objective

An operator in Brazil wanted to drill a 12¼-in section from an offshore fixed platform. The well plan specified a 3D trajectory of 2°/30-m dogleg severity (DLS) for almost 1,500 m. Previous wells from this platform were drilled by directional drillers in manual mode, sending downlinks from the surface to change the steering ratio and toolface on demand to follow the proposed well trajectory. This field test assessed the autonomous downhole control system’s ability to navigate the curve.

Results

The PowerDrive Xcel™ RSS was recommended for a single run bottomhole assembly (BHA) because the auto-curve mode adjusts the steering ratio automatically based on required DLS and toolface.

Auto-curve mode was engaged once the BHA was out of the casing shoe at 10° inclination. The directional drillers varied the DLS and toolface as necessary, which were the only two inputs needed to drill to total depth (TD). Using auto-curve mode reduced the number of downlink commands by 33% from drilling in manual mode.

The autonomous downhole control system accounted for the influences of drilling parameters and formation characteristics on the trajectory response. The PowerDrive Xcel RSS reacted quickly to the changes compared with manual drilling. Thus, the drilled well path was closer to the planned wellbore path, and the risks associated with directional drilling uncertainties were minimized. Both the operator and the directional drillers provided positive feedback on auto-curve’s performance.

Using the autonomous downhole control system enabled the operator to improve net ROP by 38%, beating the perfect well net ROP by 10%. Additionally, total drilling time was reduced by 25 hours compared with the budgeted well time and 17 hours compared with the perfect well time for this field.

Key Performance Indicator in 12¼-in Section	Perfect Well Time	Budgeted Well Time	PowerDrive Xcel RSS Time
Total drilling time, h	61	69.15	44.5
Net ROP, m/h	45	na	49.6

PowerDrive Xcel RSS with auto-curve improved drilling efficiency for the operator by increasing ROP, reducing downlink commands, and decreasing total drilling time.

Well log of continuous and desired inclination, toolface, continuous azimuth, and steering ratio.

The operator drilled almost 1,500 m at 2°/30-m DLS with the autonomous downhole control system to adjust steering ratios and improve drilling efficiency.

Graph of the overlaid plan and drilled path and the engagement of auto-curve mode before the curve.

The PowerDrive Xcel RSS auto-curve mode adjusted the steering ratio automatically based on the required DLS and toolface. The drilled well path (blue) was nearly identical to the planned trajectory (grey), and the risks associated with directional drilling uncertainties were minimized.

The graph maps the 3D turn accomplished by the PowerDrive Xcel RSS auto-curve mode.

Auto-curve mode on the PowerDrive Xcel RSS successfully drilled the 3D trajectory of the well, mapped here from a bird's-eye view. The system automatically adjusted the steering ratio based on the required DLS and toolface.