High elevation drilling

Southern Bolivia can be considered an idyllic place except when you go there in winter to conduct a survey. Françoise Aye* tells us about the particular conditions of this mission.

Forage dans le cadre d’une prospection pour l’or sur le Cerro Galapago (Bolivie, 1997)
Drilling as part of a gold prospecting on Cerro Galapago (Bolivia, 1997). © BRGM

“July, South America, the tropics, taken together, first evoke the holidays, the heat, the humidity and the lush vegetation of the Amazon basin. But in Cerro Galapago, in southern Bolivia, between 4,000 and 5,000 metres above sea level in the Andes Mountains, people and engines lack oxygen. The lumpy top of the mountain is reminiscent of turtle backs, but the slopes are steep, and the slightest movement requires enormous effort. In winter, the desert is icy, and the temperature drops to about -30°C every night.

Drilling under these conditions is a considerable achievement. We called on a Canadian company accustomed to working under extreme conditions.

The drill was installed in a container

For the comfort of the drillers and to prevent the diesel fuel from freezing, the drill was installed in a container, which helps to keep the engine warm and protect workers from the wind.

We were looking for gold in a volcanic formation composed of soft, friable weathered rocks criss-crossed by a silica lattice. These differences in mechanical behaviour made the drillers’ task difficult. The chief driller and his assistant were listening for any suspicious noise from their machine.”

*Françoise Aye is a former geological engineer, who worked at BRGM, in the mineral deposits department in Orléans.

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