WHD- DRILLING Method

BHG Brechtel invented a new registered drilling method for 480 mm horizontal drilling in water saturated aquifers. The developing process went on for nearly three years and was administrated by the inventor, Mr. Horst Derwand in close cooperation with the engineering company IB Dieterle. Notable companies of Mechanical Engineering and IT-Technology took part in this development because of their contribution of technical knowledge and mechanical skills.

WHD stands for WATER HYDRAULIC DRILLING. The use of pure water in combination with such high efficiency and compactness is absolutely new and environmentally friendly.The complete drilling system has three main parts witch share the same high pressure water supply. The Drilling Tool with the Drilling Head / Pilot removes and crushes the soil / rock. The so called “Pig” is the tool witch is responsible for locking the entire drilling system in its position during the drilling process. Additionally this tool manages the automatically independent movements of the drilling system within the drilling pipe. The combined Water Hydraulic and Electronic Control Tool monitors and controls all working functions of the drilling system.

By using this new drilling method we are now able to perform horizontal drilling in all formations including hard rock. Within the horizontal laterals we are able to install screens by using the established PREUSSAG-Gravel-Pack-Method. During the drilling process the existing kf-value / conductivity of the aquifer is not negatively affected because of the use of pure water without any drilling mud.

An additional benefit of the new WHD-drilling technique comes from the backflow water after its use in the hydraulic motors. This backflow and additionally flushing water enables us to use this drilling method in soil even without ground water. The amount of backflow is sufficient to carry out the cuttings.

When the invention research started we decided to use state of the art engineering and IT-technologies. Otherwise we could not have reached the desired results. We had to break new ground when we designed the motor part during development of the water hydraulic control. We found a solution for wireless data transfer between the drilling system and the control panel. This has never been done before in such an application.
The electronic control is self sustaining without any external electric supply.

During drilling we reached a high directional stability due to the arrangement of cutting tools at the drilling head. The water pressure supply is currently about 160 bar with about 160 l/min (about 2300 psi with about 43,3 gal/min). From this water pressure supply the drilling tool creates a very high torque moment of up to 10500 Nm (about 7750 ft.lb) despite the compactness of the drilling system.

The „Pig“ locks the drilling system within the drilling pipe by using a kind of elastic clamp elements. These clamps operate at the same water pressure as the drilling tool. When the final length of the lateral is reached a “step function” will move the entire drilling system out of the drilling pipe automatically. The registered technology of the “Pig” offers more positive effects during drilling into hard rock.

The WHD-drilling method has successfully performed the first test in practice. We drilled a horizontal lateral in a new build Radial Collector Well.

A report about this first practice test and our experiences will be published in the reputable professional journal for well construction “bbr” in Germany. Soon we will provide you with an English translation.