Why water-powered drilling is enviromentally friendly
When drilling with water-powered equipment, there is no introduction of oil or dust to the ground or to the air. The consumed water is often completely safe to discharge. If an unwanted substance (like chalk) is brought from the borehole to surface with the drill cuttings, it may require a separate sedimentation unit.
As the velocity of the water is low, the flushing effect is reduced when drilling in maritime environment. The disturbing of the sediment is kept to a minimum.
Why water-powered drilling gives lower power consumtion
Water is a media that can easily be pumped.
To power a 6” air-powered DTH hammer, a compressor that gives 570 l/s at 35 bar is required; the required power is 430kW.
To power a 6” water-powered DTH hammer, a high-pressure pump that gives 490 l/min at 200 bar is required; the required power is 190kW.
A water-powered DTH system usually consumes less than half of the energy required by an air-powered DTH system. And if the work environment doesn’t allow the compressor to be stationed close to the rig, the pressure loss in the piping system can be considerable.
There is a clear difference in power consumption
1. With other solutions 2. With Wassara
Better working conditions
All mechanical machines need some kind of lubrication to operate over their lifetime. A water powered hammer uses the pressurized water for more than just powering the hammer and bringing the cuttings to surface. Water also acts as a lubricant and eliminates the need for any oil. This means that the ground is not polluted and workers or people in the vicinity are not exposed to oil mist or dust caused by the drilling process. This is particularly important in underground work sites where ventilation is limited.
With an air-powered DTH hammer, the lubrication is usually done by continuously adding oil to the drill string. The oil not only lubricates the hammer mechanism, it also follow the air through the hammer and out into the rock formation and environment.
Water-powered hammers are also considerably quieter than top hammers, as the percussion unit is down the borehole. The sound level is also significantly lower compared to air DTH, since the borehole is almost always full of water, dampening the noise.