New rotary steerable system offers high build rates exceeding 17°/100 ft
Schlumberger unveiled its new PowerDrive Archer high-build rate rotary steerable system (RSS) at the 2011 SPE/IADC Drilling Conference on 1 March in Amsterdam. According to Andy Hendricks, president of Schlumberger drilling and measurements, the system has consistently drilled high build rates in wells exceeding 17°/100 ft during field trials.
“This technology maximizes reservoir exposure, reduces risk and increases potential hydrocarbon production,” Mr Hendricks said. The hybrid steering system is a combination of both push-the-bit and point-the-bit technologies, allowing the tool to deliver high build rates from any deviation and do so accurately from vertical.
According to Mr Hendricks, the control section is based on the company’s PowerDrive X6 control section. It contains a new torque assembly for higher torques to maintain a better toolface. It also includes improved robustness for dealing with higher temperatures on the bearing systems in this tool and with some of the contaminated mud systems sometimes seen on land rigs.
The steering section of the assembly has been tested in more than 100 wells across North America and the Middle East. Where the pads in the PowerDrive X5 and X6 systems have pads on the outside of the drill collar, the PowerDrive Archer has the pads on the inside of the collar so they are pushing in a controlled environment, minimizing pad wear and controlling the consistency of the build rate. “We’re getting a combination of push and point at the same time,” Mr Hendricks said.
The PowerDrive Archer has the ability to drill a very high curvature in wells. Schlumberger said it has tested the tool where clients have needed to build 8-9° in the drilling section; the new RSS can build from 15-17°/100 ft. This capability delivers well profiles previously possible only with motors.
All external parts on the new RSS rotate, which improves hole cleaning and reduces risks of stuck pipe. The system can also drill complex 3D trajectories and open-hole sidetracks from any inclination, according to the company. It can drill vertical and horizontal sections, in one run, with no flat time for trips to change the bottomhole assembly.
Mr Hendricks pointed out that one operator in the Marcellus Shale saved more than US$1 million by eliminating 10 days of drilling time per well, in addition to acquiring high-quality wellbores, which facilitated completions. In the Middle East, an operator was able to maintain verticality longer, drilling the 12 ¼-in. section faster and pushing kickoff deeper with the higher build rate achieved in the 8 ½-in. section.
In another well, the new tool was able to kick off from vertical, drill a 3D curve with more than a 100° change in azimuth, and hold an unplanned tangent section made necessary by a landing-point change of more than 70 ft. The RSS quickly built to 16°/100 ft once the geological marker was found, and then soft-landed the well from 85° to 90° at a 2° build rate.
PowerDrive Archer is a trademark of Schlumberger.