North Sea trials deliver strong results
Stina Ophaug Boge, PSW Group
Identification and control of drillstring vibrations has become an increasing priority for the drilling industry over the past two decades, with more complex wells being accompanied by greater incidence of downhole tool failures. The APS Technology SureDrill Active Vibration Damper (AVD) is a new drilling optimization development that employs similar technology to that applied to adaptive shock absorbers by the automotive sector.
A major offshore operator and a service company recently deployed the AVD tool on an operation in the Norwegian continental shelf (NCS) with impressive results. The run with the tool was the best achieved on the field, drilling more footage at a faster penetration rate than the previous eight wells. More importantly, it also saved the cost of one or more trips for bottomhole assembly changes.
PSW Group has signed an exclusive partnership agreement with APS Technology for distribution and continued development of the SureDrill-AVD tool for offshore operations, and is confident of a strong uptake, with drilling becoming more challenging as the industry explores and develops harsher environments.
The SureDrill Active Vibration Damper. (All images courtesy of PSW Group)
The main objective with managing vibrations is to ensure consistent drilling performance in continuously changing conditions, while avoiding potential dysfunctions such as severe vibration and stick-slip that can lead to tool failure, bit damage, and low rate of penetration (ROP). The financial impact of such failures can be significant in terms of the cost of repairing or replacing damaged components, and the extended drilling time caused by unplanned events. Although progress has been made over the last several years, the industry is still working to find a solution that achieves more reliable drilling performance.
So how did an automotive shock absorber technology make its way to North Sea drilling? Klaus Magnus Wergeland, now Oilfield Manager at PSW Group, was watching a TV commercial for Hummer and its ‘MagneRide’ adaptive suspension system and wondered why this technology had not been applied to drilling. Although downhole tools bear little relation to a car, both need to adapt to changing vibrations to run smoothly.
The MagneRide is an electronically controlled adaptive damping system that automatically reacts to the texture of the road and adjusts the damping in real time. The essential elements to the system are a viscous liquid containing magnetic particles (magnetorheological fluid), sophisticated motion sensors, and an electrical control unit which receives information from the motion sensors and applies an electrical charge to the particles. This magnetizes the particles and causes the viscosity of the liquid to change, thereby stiffening the suspension.
PSW Group’s research revealed that APS Technology had adapted and patented the technology for use in downhole drilling applications and had been developing its version and associated control algorithms for more than a decade. While the SureDrill-AVD is based on similar principles as the ones behind the magnetic adaptive suspension system, various unique requirements had to be addressed to make the technology work in a drilling environment. Following contact between the two companies, it soon became clear that APS’ technological advancement was a good fit with PSW Group’s offshore experience.
On the left is with the AVD tool. On the right is without the AVD tool.
Damping based on real-time data
As with the adaptive suspension system for cars, the SureDrill-AVD receives real-time data and automatically adjusts the damping by means of magnetorheological fluid viscosity changes. An integrated motion sensor measures displacement several times per second and changes the damping factor over a 7-to-1 range based on observed drilling conditions. By keeping tool string damping in the right range for current drilling conditions, the AVD significantly reduces axial, lateral and high frequency vibrations, and stick slip; this allows for a more consistent weight on bit, more consistent drilling torque, and increased ROP. It essentially decouples vibrations from the lower BHA from the rest of the drillstring, minimizing drillstring dysfunction, and leading to cost savings both on drilling operations and equipment.
On the left is with the AVD tool. On the right is without AVD tool.
When SureDrill-AVD was first tested on the NCS, the tool was used to drill a 1,656-m (5,433-ft) 12¼-in. section from casing point to casing point, in a 66° tangent section. The entire section was drilled in one single bit run: analysis of the data revealed that tangential resonance was significantly reduced, and the vibration analysis clearly shows a substantial decrease in axial and lateral vibrations, with an increased ROP due to mitigated vibrations and optimized parameters.
Field data also showed a significant decrease in stick slip, minimizing destructive vibrations.
After the successful run on the NCS, the tool has been employed on several wells, again with promising results, and PSW Group now sees additional applications for the tool. The company plans to continue developing its partnership with APS Technology and to expand the tool fleet. Potentially, SureDrill-AVD could improve drilling efficiency worldwide, allowing the industry to drill longer and faster with fewer bit trips and reduced downtime on downhole equipment. •
The author
Stina Ophaug Boge is Communications and Marketing Manager in PSW Group, and held positions within the oil and gas industry for the past eight years. She previously worked on global communication for FMC Technologies, Subsea Services. She holds an M.Sc. in Marketing from Leeds Metropolitan University and is a member of the board of the Society of Petroleum Engineers Bergen Section.
