Being 2006.87m in depth, Wulanhada geothermal well was constructed with 30 type oil drilling rig in the Inner Mongolia Autonomous Region Chayouhou Banner, most drilled formations, more than 1500m, were metamorphic rocks, the roller bits were seriously damaged; and 18 times of coring were required for the construction. HJ637G roller bit was selected, the drilling efficiency per hour was up to 0.8～1.2m and the service life reached 80～100h. Chuan 7-4 double tube single rotary coring barrel was used, the core recovery could be 70%～95%.