Edimac has taken part in the “Reforco de Potencia – Venda Nova III” project in Vieira Do Minho, Portugal. The project includes a new hydroelectric plant that will significantly increase the power of an existing plant and which will begin to produce power in 2015. A dam on the Rio Cavado has so far been built as well as an underground plant with various auxiliary and access tunnels. Edilmac began drilling 6 wells in April 2011 and completed these in May 2014. The work involved three stages: the drilling of a vertical well 68 m deep and 2.44 m wide; the excavation of 3 other wells (two vertical ones and another at 45 degrees) between 50 and 85 m deep and 2.44 and 1.55 m in diameter; and, lastly, the creation of 2 larger vertical wells measuring 360 m deep and 5.46 m wide. The type of rock was granite and granodiorite considered medium strong with a UCS range up to 160 MPa. The Raise Borer machine RBM 73 DC was used for the narrower wells while the Raise Borer machine RBM Herrenknecht 550 VF and Directional Drilling RVDS equipment were used for the larger wells.
Despite the major geological difficulties and the problems associated with drilling wells of different types and sizes, the work went perfectly to plan and entirely in compliance with the environmental and safety regulations.