New Achievement in Seeking Deep Reservoir at Yangbajain Geothermal Field, Tibet, China

Abstract

The downhole temperature of 202;C at 959 m depth was recorded by a explo at Sulfur Mine, the uphill terrain no the borefield, of 4 L I Yanbajain Geoth the exploitation has been restricted within the shallow reservoir of lim- I ited size for more than thCE years. n e exp1oratf;eh- I ling also reveals the fracture permeability within the I granite at &deep level, and a systematically vertical I zonation of hydrothermal alteration repre'hnted by advanced argillization + acid sulfate alteration- * silicification and brecciation - illite + epidote alteration, suggesting the upflow condition of A geothermal fluid. It is believed that the upflow zone of 1 Aa-Yangbajain geothermal system is located at, or even northwestkrz$ to, Sulfur Mine, and probably a deep hot reservoir was created there.