Overburden Drilling System

The name “Overburden Drilling” results from the composition of the earth‘s crust. The bedrock is covered with loose layers of earth consisting of sand, gravel, boulders combined with loose ground and other deposits. All these formations are grouped together under the umbrella term “Overburden”, which overlies the bedrock. 

Certain drilling processes make it necessary to support a borehole wall with tubes. Based on the requirements and circumstances at hand, different drilling variants can be used, pure rotary drilling with a rotary head or rotary percussion with a hydraulic drifter or with a double head drilling unit rotary / rotary or rotary / rotary / rotary-percussion. Please see below the different variants in detail.