James, our most recent engineering placement has returned from the village of Bo in Sierra Leone. Here is summary of the progress made.
Repair and maintenance
James carried out some much-needed repairs and maintenance to the drill tools which had been stored on site since July 2010. Access to materials is always a challenge in the location Developing Technologies works, but James showed great ingenuity and resourcefulness in successfully repairing the drill engine as well as the pulley system.
Drill behaviour through different rock types
James’ research involved testing the percussion drill in new rock types.
Drilling challenges below the water level
A major challenge associated with percussion drilling is drilling into material that is saturated with water. This happens when either the main aquifer is reached or when a lot of water is added to aid the drilling process. As the drill moves through saturated material, the walls often do not have enough cohesion to maintain their shape and can slump into the bottom of the hole. This means that the drilling process becomes slower – more material having to be excavated without increasing the well depth.
Building on the operational data from James work, DT is developing several possible solutions to this problem which we aim to test in early 2011.
