High-Temperature Slurry System for Dry Hot Rock

Abstract

Dry hot rock (DHR) is a kind of rock without water or steam lying 2-6 km underground with a temperature of 150-650°C. Domestic DHR at 3.5-7.5 km depth had a temperature of 150-250°C with a total energy of 6.3· 10²⁴J, which was 1320 times the total energy consumption of China in 2010 assuming 2% of available exploration volume. Mixing of H₂S, H₂SO₃, etc. in the steam and hot water of a DHR well can easily corrode the pipe materials and the well-stabilization slurry. A high-temperature sulfur-corrosion-resistant slurry system containing HTR2000 (retarder) (density 1.86 g/cm³, initial consistency 12 Bc, consistency time 252 min, water loss 23 mL in 30 min (API), bleeding rate 1.20%, 1-d strength 34.4 MPa, 28-d strength 25.6 MPa) that met all DHR well-stabilization requirements was developed.