Underground drilling


Underground exploration drilling

In the short term research program (1995-98) of the Boda Claystone Formation the objective of the program was to investigate the suitability of the formation for hosting high level radioactive waste repository in underground. We have implemented drilling works to reach and penetrate the transition of the claystone and the sandstone overburden and a significant cracked zone within the Boda Claystone Formation. The underground drillings were implemented by keeping direction with HQ, NQ, NQ-U,BQ diameter, wire-line technology.
The rock bored through were: sandstone, claystone, siltstone. The depth varied between 70 and 245 m. The core recovery was 95 %.
A given part of the boreholes were reamed according to the requirements of the Client to make them suitable for large diameter multipacker tests. (for the Canadian AECL URL Hydrogeology).
During the rock mechanical drilling program we drilled boreholes for hosting extensometers, triaxial cells of overcoring tests.
During the underground drilling program . according to the requirements of the Client . we applied clean water as flushing we didn.t use mud improvers at all.