Sonic drilling is a soil penetration technique that strongly reduces friction on the drill string and drill bit due to liquefaction, inertia effects and temporary reduction of porosity of the soil. The combination makes penetrating for a large range of soils easy for our Sonic rigs and tooling. The penetration rates in most bedrock are faster with this technology also.
Sonic vibration is generated within the sonic drill Head.
The oscillator within the sonic drill head generates a high-frequency, resonant energy which is directed down into the drill string. During drilling the resonant energy is combined with rotational movement. This evenly distributes the energy which impacts the drill bit and drill string of tooling. The drill operator can control the amount of sonic vibration the drill head generates to match the force needed to optimally penetrate the soil and bedrock formations.
When you engage the Sonic drill head, the entire drill string is brought to a vibration frequency of up to 150 Hz. This causes a very thin zone that directly surrounding the drill string and bit to lose structure. This reduces the friction of the soil and drill cuttings to become fluid and be able to be flushed or removed from the bore hole with ease.
The vibrations of the drill bit cause the soil to lose structure which changes density and porosity. This way the soil & cuttings move in the sample barrel and up the drill string to help the tooling advance freely.
The liquefaction and inertia effects enable you to collect long and continuous samples. Due to the vertical high-frequency movement the drill string stays extremely straight with very little deflection.
Less power, fewer problems
Because of the reduced friction on the length of the drill string, sonic drilling needs less power to achieve the same effect as conventional drilling. This unique characteristic of sonic drilling prevents torsional forces on the drill string. Another benefit of applying sonic high frequency is the ease of retrieving the drill string, even in quick expanding clays or boulders and difficult conditions. All the drilling rods, casings and tooling are pulled faster and easier.
Sonic drilling is clean drilling
There are situations where you want to avoid the usage of drilling mud, air or even water while drilling. Sonic drilling does not necessarily require air or drilling mud while drilling. This makes sonic drilling the preferred method for geotechnical, geo-construction and environmental applications. Also there are special projects where sonic drilling can and has run dry in overburden conditions.
Environmental projects can realize significant cost savings using the Sonic drilling method. These types of projects can require a substantial amount of time and consequently money, in order to properly dispose of investigation derived waste.
In a mining project, specifically a leach pad, adding water or air is a disturbance and can influence the mechanical properties of the soil. In extreme cases it can cause erosion which could lead to a failure such as a partial landslide.
Sonic Drill Rigs & Tooling are the best drilling technique for most overburden conditions.
Where conventional drilling methods chronically struggle to obtain a continuous core sample in unconsolidated formations. Sonic drill rigs & tooling excel in penetrating soft, mixed , hard and all other types of overburdens. Also providing highly undisturbed samples with a excellent track record of recovery.