Operators are looking for cost-effective ways to drill faster and longer laterals since the more footage that they can expose, the higher the level of returns, said Juan Restrepo, product champion for RSS for Schlumberger.
“When you measure drilling efficiency, it can be seen in two ways—drilling faster and minimizing the number of BHAs used to drill to the objective. All the development we have had in recent years has to do with how to have the system provide a quality hole for our client in the shortest period of time,” he continued.
There are three points that have to be hit to reach new levels of performance—drill faster, the ability to drill longer wellbores in the target zone and provide high quality holes. “No matter how far you drill, if you don’t have a hole that can be used, it is going to be a waste of time and money for the whole well construction and production process,” he added.
Schlumberger has added two new members to its PowerDrive RSS family. The PowerDrive Xcel RSS is focused on offshore and ultra-extended-reach-drilling (ERD) wells。
“The ERD wells are getting longer and longer, so downhole automation is becoming more critical for the consistent performance of directional tools, since building micro-tortuosities across the extended lengths reduces the amount of energy required for the actual drilling process,” Restrepo explained.
“There are no more commands to be sent to the tool. The tool is going to measure its orientation downhole and do exactly what it needs to keep the target set,” he said. That takes the human out of the equation.
At 350 revolutions per minute, the tool can still measure downhole both inclination and azimuth. “One of the quests we had [in the design] was to accurately measure the inclination and azimuth dynamically to confidently let the tool decide for itself what to do without requirements from the surface. That is a very important point of this,” he emphasized.
Vibration affects where energy is going in the drillstring. “For drilling performance characterization of the vibration patterns is critical. Both technologies provide triaxial measurement of both shocks and vibration,” Restrepo continued.
The PowerDrive Xcel RSS also was shown to be effective in open-hole and cased-hole sidetracks due to the inclusion of a gyro and a customizable bend offset. The tool can measure rotation and stick-and-slip in magnetic interference environments. It also maintains directional control through the zone of exclusion, he added.
PowerDrive Xcel* RSS is part of the PowerDrive* RSS family of fully rotating steerable systems that minimize the risk of sticking. The entire family has a complete direction and inclination sensor package close to the bit for precise well placement and independently generates power for 3D steering and control.
In any drilling environment, the PowerDrive RSS family delivers the power required to place wells accurately with superior borehole quality while ensuring maximum drilling efficiency.
The PowerDrive Xcel RSS was designed for use in high-profile directional drilling operations. In contrast with many RSS units, which rely on a magnetic and gravity field measurement for steering control in areas with high magnetic interference, such as drilling out of a whipstock window and close to offset wells or ferrous formations, the PowerDrive Xcel RSS provides inertial directional control in deviated sections. This feature, which can be toggled on and off by a downlink, enables tight directional control even hrough the magnetic zone-of-exclusion (ZOE). Its gyro can also be used as a redundant backup system to magnetic control. The PowerDrive Xcel RSS also has the ability to sense magnetic and inertial stick/slip as well as shock and vibration on three axes, enabling the tool to completely monitor downhole drilling for maximum drilling performance in any environment.
Versatile and customizable drilling system
The system features automated closed loops for simultaneous inclination and azimuth and can be customized for ERD applications to optimize the curvature delivery and provide tighter control in long tangent sections. Reinforced critical components deliver greater durability for extended periods and through harsh environments. Evolving from one size fits all to an optimal configuration to maximize performance, PowerDrive Xcel RSS can be also configured to improve the curvature delivery in dogleg severity (DLS) assurance applications and to deliver on challenging environments. The PowerDrive Xcel RSS has a gamma ray sensor placed near the bit, which enables geostopping, early identification of zones of interest, and more accurate data that enhances real-time decision making.
System redundancy for unrestricted drilling
The PowerDrive Xcel RSS was designed for use in high-profile directional drilling operations. In contrast with many RSS units, which rely on a magnetic and gravity field measurement for steering control in areas with high magnetic interference, such as drilling out of a whipstock window and close to offset wells or ferrous formations, the PowerDrive Xcel RSS provides inertial directional control in deviated sections. This feature, which can be toggled on and off by a downlink, enables tight directional control even through the magnetic ZOE. Its gyro can also be used as a redundant backup system to magnetic control.
The PowerDrive Xcel RSS also has the ability to sense magnetic and inertial stick/slip as well as shock and vibration on three axes, enabling the tool to completely monitor downhole drilling for maximum drilling performance in any environment.
APPLICATIONS
■ Sidetracking
■ Zone-of-exclusion (ZOE) drilling
■ Geostopping
■ Dogleg severity (DLS) assurance
■ Extended-reach drilling (ERD)
BENEFITS
■ Delivers sidetracking capabilities
■ Increases geological certainty near the bit
■ Provides redundant control for trajectory optimization and superior reliability
■ Enables both higher DLS and smoother well profiles
■ Enables longer runs in standard PowerDrive vorteX* RSS configurations
CNOOC China Ltd. needed to drill a 121/4-in section to reach TD. However, the optimal trajectory required an azimuth of 0.09°—forcing the well design to plot through the ZOE and presenting additional accuracy challenges. Avoiding the ZOE meant that well tortuosity would increase tremendously. It would also force a much longer well path, increasing other drilling costs. It was determined that the PowerDrive Xcel* rotary steerable system in gyro mode was the best solution. CNOOC successfully reached the TD with a center-to-center distance between planned and actual trajectory of 2.14 m [7 ft]