Drive of Your Life
31 May 2007 10:42
As oil companies search for new fields in deeper waters, there is a booming demand for drilling vessels fitted with the very latest technology. This has been good news for electrical engineering and automation company ABB. In the past year, ABB electrical, thruster and drive systems were specified in more than half of the 24 new rigs and drill ships ordered. These systems enable vessels to remain in position over drill sites thousands of meters below, even in harsh weather and heavy seas.
ABB was the first company to introduce AC drilling drives in the early 1990s. The company now has drilling drives in over 50 drilling platforms and vessels worldwide and more than 200 topside AC drive systems in downhole and subsea pumps. As a result, ABB is widely regarded as the undisputed leader in supplying AC drives for offshore and onshore drilling, and subsea production systems.
AC drilling drives offer immense benefits: they last longer, as the motor can adjust its speed to provide a smooth, gradual drilling action; they use less energy, reducing the impact on the environment; and they offer improved drilling performance across a wide speed range. The ultimate pay off, however, is a dramatic cost saving, due to reduced drilling time, lower labour and operating costs, and improved safety and drill control.
Variable Speed Drive (VSD)
At the heart of the AC drilling operation is a versatile Variable Speed Drive (VSD). Technological advances have resulted in far more powerful and flexible VSDs capable of controlling the speed
of drilling on barges and platforms, jack-up rigs, semi-submersible rigs and floating drill ships.
Drilling drives offer responsive, high-accuracy speed and torque control, and they have excellent dynamic characteristics across the entire speed range from zero to maximum. One of the keys
to this success was the arrival, in 1996, of an innovative motor control technology called direct torque control (DTC). DTC has an unprecedented ability to accurately control the torque and speed of drilling applications.
The VSD provides straightforward and precise control that enables operators to quickly find the optimum drilling speed. The VSD’s sophisticated electrical brake control ensures that top drive and draw-work applications are undertaken safely and reliably. All applications powered by VSDs, including mud pumps, cement pumps, cutting injection pumps and anchor winches, can be controlled by the operator using a single joystick control.
Liquid-Cooled Industrial Drive
While the AC drive is now regarded as a mature technology, there is always scope for innovation, and there is a great need for well designed, verified and proven drive technology that has been tested to the stringent standards of the marine authorities. Recently ABB launched a liquid-cooled version of its hugely successful ABB industrial drive, which is some 30% shorter and 40% smaller in footprint than previous generation drive systems. In drilling applications, where space is restricted, liquid cooling avoids the need for a large, costly and noisy air conditioning plant in the control room.
One important recent development in AC drive technology is that the drive modules are now three-phase. Earlier drive modules were single phase, and it was necessary to combine three modules in parallel for a three-phase system. The new technology, with three-phase built into one module, allows other modules to be used to maintain uptime on the rig with reduced power, in the event of one failure.
Motors, High-Voltage Transformers and Low-Voltage Switchgear
As well as supplying drives, ABB’s can provide a complete package consisting of motors, high-voltage transformers and low-voltage switchgear.
The regulatory environment in which drives operate is complex and constantly changing. However, ABB adheres to the relevant regulations and in many cases surpasses them. Faced with a high oil price and a low level of surplus capacity, oil companies and offshore drilling contractors are searching for new reserves in locations where they were previously considered inaccessible or economically unviable. The future for VSDs, it would appear, is very bouyant.
For more information on this company:
ABB - AC Drive Systems for Drilling and Subsea Production
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